ARTICLE | doi:10.20944/preprints202308.0117.v1
Subject: Chemistry And Materials Science, Theoretical Chemistry Keywords: reaction mechanism, solvent, antioxidant, metal influence
Online: 2 August 2023 (08:16:52 CEST)
Antioxidants are molecules that neutralize free radicals. In general, the reaction mechanisms of antioxidants are well known. The main reaction mechanisms of antioxidants are electron transfer (ET), proton transfer (PT), H atom transfer (HAT) and radical adduction (RAF). The study of these mechanisms is helpful to understand how antioxidants control high free radical levels on the cell. There are many studies focused on determine the main mechanism of an antioxidant to neutralize a wide spectrum of radicals, mainly reactive oxygen species (ROS) type radicals. Most of these antioxidants are polyphenols type compounds. Some esters, amides and metal-antioxidants have shown antioxidant activity. There are few experimental and theoretical studies about the antioxidant reaction mechanism of the aforementioned compounds. In this work, we shown the reaction mechanism proposed of an amide and its metal-antioxidant counterpart. We show how the presence of the metal increase the electron transfer on polar media and the H transfer in non-polar media. Even though, esters and amides are non-polar compound, the scavenger activity is good for the metal-antioxidant compound in no-polar media
ARTICLE | doi:10.20944/preprints202305.0752.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Swietenia macrophylla; Nanoparticles; Antioxidant; Cardioprotector; Diabetes
Online: 10 May 2023 (12:02:01 CEST)
Abstract: Hyperglycemia caused cardiac cell damage by increasing ROS production in diabetic complications. The current study will prove the antioxidant activity of Swietenia macrophylla (S. macrophylla) extract nanoparticles as a protector against Streptozotocin (STZ)-induced cardiac cell damage. In this research, high-energy ball milling is used to make S. macrophylla extract nanoparticle. Furthermore, characterize the size of S. macrophylla extract nanoparticles with Dynamic Light Scattering (DLS). Forty male rats were divided randomly into five groups. Control group: rats received orally aqua dest; Diabetic group: rats were injected STZ intraperitoneally; S. macrophylla group: rats were injected STZ and given orally with S. macrophylla extract nanoparticles. The DLS showed that the S. macrophylla extract nanoparticles size was 91.50 ± 23.06 nm. Injected with STZ significantly increased cardiac tissue of MDA levels, serum of CK-MB and LDH levels. STZ also significantly reduced expression of Nrf2, level of SOD and GPx in cardiac tissue compared with control group (p<0.05). In contrast, administration of S. macrophylla extract nanoparticles can prevent STZ-induced cardiac cell damage by decreasing level of CK-MB and LDH in serum, and level of MDA in cardiac tissue. S. macrophylla extract nanoparticles also significantly increments Nrf2 expression, SOD and GPx levels in cardiac tissue. These effects are related to the prevention of cardiac histopathological alteration (degeneration and necrosis) in diabetic rats. These results suggest that S. macrophylla nanoparticles might be a potential cardioprotective agent against STZ-induced cardiac cell damage due to its antioxidant properties
ARTICLE | doi:10.20944/preprints202304.1066.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: crocin; antioxidant properties; pulse radiolysis; gamma radiolysis; molecular simulation; mechanism.
Online: 27 April 2023 (09:55:53 CEST)
The successive steps of the oxidation mechanism of crocin, major compound of saffron, by the free OH• radical are investigated by the pulse radiolysis, steady-state (gamma) radiolysis methods and molecular simulations. The optical absorption properties of the transient species and their reaction rate constants are determined. The absorption spectrum of the oxidized radical of crocin resulting from the H-abstraction presents a maximum at 678 nm and a band at 441 nm, almost as intense as that of crocin. The spectrum of the covalent dimer of this radical contains an intense band at 441 nm and a weaker one at 330 nm. The final oxidized crocin, issued from radical disproportionation, absorbs weaker with a maximum at 330 nm. The molecular simulation results suggest that the OH• radical is electrostatically attracted by the terminal sugar and is scavenged predominantly by the neighbor methyl site of the polyene chain as in a sugar-driven mechanism. Based on detailed experimental and theoretical investigations, the antioxidant properties of crocin are highlighted.
ARTICLE | doi:10.20944/preprints202111.0577.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Ciona robusta; tunicate; metals; typical 2-Cys peroxiredoxins; antioxidant enzymes.
Online: 30 November 2021 (17:58:47 CET)
Typical 2-Cys peroxiredoxins (2-Cys Prdxs) are proteins with antioxidant properties belonging to the thioredoxin peroxidase family. With their peroxidase activity, they contribute to the homeostatic control of reactive oxygen species (ROS) and, therefore, participate in various physiological functions such as cell proliferation, differentiation, and apoptosis. Although Prdxs have been shown to be potential biomarkers for monitoring the aquatic environments, minimal scientific attention has been devoted to describing their molecular architecture and function in marine invertebrates. Our study aims to clarify the protective role against stress induced by exposure to metals (Cu, Zn, and Cd) of three Prdxs (Prdx2, Prdx3, and Prdx4) in the solitary ascidian Ciona robusta, an invertebrate chordate. Here we report a detailed pre- and post-translational regulation of the three Prdx isoforms. Data on intestinal mRNA expression, provided by qRT-PCR analyses, show a generalized increase for Prdx2, 3, and 4, which is correlated to metal accumulation. Furthermore, the increase in tissue enzyme activity observed after Zn exposure is slower than that observed with Cu and Cd. The obtained results increase our knowledge of the evolution of anti-stress proteins in invertebrates and emphasize the importance of the synthesis of Prdxs as an efficient way to face adverse environmental conditions.
ARTICLE | doi:10.20944/preprints202308.1769.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: antioxidant; hawthorn; rat; ultrasound
Online: 28 August 2023 (10:35:48 CEST)
The hawthorn fruit, a member of the Rosaceae family, is a medicinal plant with numerous therapeutic properties. It exhibits a wide range of variants, with Crataegus tanacetifolia being Turkey's most widely recognized species. The hawthorn fruit has various biological activities, including anti-inflammatory, antibacterial, antioxidant, immune-modulating, and anti-carcinogenic properties. Vinegar was produced from the hawthorn fruit and the techniques of pasteurization and ultrasound were employed to enhance the antioxidant capabilities and extend the shelf life. A total of 56 mature Wistar-Albino rats were allocated into seven groups and administered hawthorn fruit vinegar via oral gavage on a daily basis. The experimental groups were classified as pasteurized (HVP) and ultrasound (HVU) treated, with two different dosage levels (0.5 and 1 mg/kg), and a control group consisting of regular vinegar. The SOD, MDA, and CAT antioxidant levels were measured using the ELISA method in plasma and liver tissue samples. The total cholesterol, triglyceride, HDL, LDL, AST, and ALT values were quantified in commercially available kits. The levels of SOD and CAT in the plasma and liver were found to be significantly higher in the HVU1 group. In a manner akin to those mentioned, the HVU1 cohort exhibited the highest HDL value. The levels of LDL were comparably low in both the thermal pasteurized and ultrasound treatment groups. This finding agrees with HDL levels and is statistically significant (p≤0.05). There were significant expressions of both CAT and SOD in HVU groups in liver tissues immunohistochemically. The possible therapeutic effects of hawthorn vinegar may boost its antioxidant capabilities and contribute to an overall improvement in quality of life.
REVIEW | doi:10.20944/preprints202308.1554.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: NRF2; ferroptosis; antioxidant; metabolism
Online: 23 August 2023 (03:28:45 CEST)
Ferroptosis is an iron-dependent and lipid peroxidation-driven cell death cascade, occurring when there is an imbalance of redox homeostasis in the cell. Nuclear factor E2 related factor 2 (NFE2L2, also known as NRF2) is key for cellular antioxidant responses, which promotes downstream gene transcription by binding to their antioxidant response elements (AREs). Numerous studies suggest that NRF2 assumes an extremely important role in the regulation of ferroptosis, for its various functions on iron, lipid and amino acid metabolism and so on. Many pathological states are relevant to ferroptosis. In cancer cells, ferroptosis is frequently found abnormal suppression. While during tissue damages, ferroptosis is recurrently promoted, resulting in a large number of cell deaths and ultimately loss of the functions of the corresponding organs. Therefore, targeting NRF2-related signaling pathways, to induce or inhibit ferroptosis, has become a great potential therapy for combating cancers, as well as preventing neurodegenerative and ischemic diseases. In this review, a brief overview of the research process of ferroptosis over the past decade will be presented. In particular, the mechanisms of ferroptosis and a focus on the regulation of ferroptosis by NRF2 will be discussed. Finally, the review will briefly list some clinical applications of targeting the NRF2 signaling pathway in the treatment of diseases.
ARTICLE | doi:10.20944/preprints202205.0296.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: melanin; antimicrobial; antioxidant; photoprotection
Online: 23 May 2022 (10:32:55 CEST)
Melanins are phenolic polymers synthesized by most of the living organisms. This pigment is mainly attributed to provide photoprotection to the organism while it was found that pigment have immense bioactivities which could be utilized in day-to-day life ranging from sun screens lotions to solar cells. This pigment produced mainly via DOPA or homogentisate in bacteria. Melanin production is usually triggered by stress condition in bacteria. Marine bacteria have been reported as good melanin producers. In this study marine bacteria capable of melanin production were isolated from sea water of Kutch region, Gujarat using tyrosine basal media. The bacteria were identified using microscopic, biochemical and molecular techniques. Melanin produced by the bacteria is extracted and purified and further characterized using physicochemical techniques. Cosmetic properties of melanin like photoprotection, antioxidant and antimicrobial properties are evaluated.
ARTICLE | doi:10.20944/preprints202302.0114.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: dry extract; antioxidant; collection of plant; phytopreparation; antioxidant compound medicine; technological parameters
Online: 7 February 2023 (02:59:51 CET)
This work is the first scientific study on the development of the composition and technology of a new antioxidant agent based on a combination of extracts of tree medicinal plants and the study of the technological parameters of a dry extract. Further draw up technological regulations for their production and their introduction into production. This study aims to the antioxidant activity of dry extract "Antioxim" was determined. In order to create this herbal collection of plant, first of all, to study the technological parameters of raw materials, such as mass size, porosity, dispersibility, free volume of layers of raw materials, water absorption coefficient of extractives, and technological process efficiency to study the effect of parameters, developed at the Department of "Industrial Technology of Medicines" of the Tashkent Pharmaceutical Institute:
ARTICLE | doi:10.20944/preprints202012.0821.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: antioxidant; cryopreservation; dog; resveratrol; sperm
Online: 31 December 2020 (15:31:06 CET)
Antioxidants have multiple protective roles in cells and can be used as a supplement to protect cells against cryopreservation-induced detrimental effects, including protecting sperm fertility quality. The antioxidant resveratrol (3,5,4-trihydroxy-trans-stilbene; RSV) has been shown to be a protective supplement for the cryopreservation of animal sperm, including human sperm. In this study, we assessed the effect of RSV supplementation on canine sperm cryopreservation. Semen was collected from four dogs and the effect of different concentrations of RSV (0, 100, 200, and 400 µM) on post-thaw quality of sperm was examined. After thawing, sperm motility was assessed using computer aided sperm analysis, and the structural integrity of the plasma membrane, acrosome, and chromatin were examined, as well as mitochondrial activity and gene expression were assessed. Dog sperm cryopreserved with 200 µM RSV showed significant improvement in motility and viability following thawing compared with that of the control group (p < 0.05). Moreover, RSV-supplemented samples showed significantly higher numbers of sperm with an intact plasma membrane, active mitochondria, and structural integrity of acrosomes and chromatin than that of control samples (p < 0.05). Furthermore, gene expression showed that RSV supplemented samples showed lower expression of pro-apoptotic (BAX) oxidative stress-related (ROMO1) and oxidative induced DNA damage repair (OGG1) whereas higher expression levels of anti‐apoptotic (BCL2) protamine-2 (PRM2), protamine-3 (PRM3) and sperm acrosome‐associated (SPACA3) genes than control. Our results suggest that RSV, at its optimum concentration, can be efficiently used as an alternative antioxidant in the cryopreservation of dog sperm.
ARTICLE | doi:10.20944/preprints202008.0438.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: acetylcholinesterase; antioxidant; Alzheimer; coumarin; selenazole
Online: 20 August 2020 (07:26:34 CEST)
Inhibition of acetylcholinesterase (AChE) enzyme is a known procedure to treat severe Alzheimer's disease through increasing the acetylcholine level in the brain and thus slowing down the progression of Alzheimer's symptoms. The approved medications are only considered as palliative and addressed some reported deficiencies. Therefore, the demand for safe and effective compounds is substantially increasing. A newly series of coumaryl 1,3-selenazoles derivatives was synthesized in four steps. Then, their antioxidant activities were evaluated using DPPH, ABTS cation radical scavenging assay and cupric reducing antioxidant capacities (CUPRAC). The anticholinesterase activities were evaluated using the Ellman method. Then, the docking studies were carried out to explain the possible correlation between in vitro anticholinesterase activity results and the ligand-receptor interactions. Ten new coumaryl 1,3-selenazoles (5a-5d series and 6a-6f series) derivatives were successfully synthesized. The DPPH radical scavenging assay showed that all tested compounds have IC50 value > 200 μM, for ABTS cation radical scavenging assay the IC50 value > 1000 μM and for CUPRAC assay the IC50 value > 200 μM. Compound 5c was found to be the most active compound against AChE and BChE in its series with IC50 value for AChE is 99.76 μM and IC50 for BChE is 140.28 μM while 6b exhibited the most potent inhibition in its series with IC50 value for AChE is 56.01 μM and IC50 for BChE is 121.34 μM. Besides, the docking studies showed that compound 5c and 6b formed π-π stacking interaction with aromatic residues at the active site of AChE and BChE, which is responsible for inhibiting the enzymes. This shows that the synthesized compounds contain skeletal structures that can interact and inhibit within the enzymes active site.
ARTICLE | doi:10.20944/preprints202001.0157.v3
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: pectin; antioxidant; lemon; flavonoids; hydrodynamic cavitation; IntegroPectin
Online: 31 March 2020 (05:00:13 CEST)
Lemon pectin extracted along with water-soluble flavonoids and other phytochemicals from citrus industry’s waste lemon peel via hydrodynamic cavitation in water, directly at pre-industrial scale and further isolated via freeze drying, shows exceptionally high antioxidant and non-cytotoxic activity. Preliminary investigation indicates also significant antimicrobial activity. These findings open the route to the development of new nutraceutical and healthcare application of a versatile biopolymer endowed with new functionality, rapidly and conveniently obtained from an abundant by-product of the agrofood industry.
ARTICLE | doi:10.20944/preprints201803.0061.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Cucurbitaceae; gourd family; nutraceutical; antioxidant
Online: 8 March 2018 (03:48:02 CET)
Fruits of chayote [Sechium edule (Jacq.) Swartz] are widely consumed in Mesoamerica, but little is known about the nutraceutical potential. This study aimed to determine the chemical compositions, antioxidant activities from the juice fruits from two commercial varieties of chayote cultivated in Mexico, as well as a proposal for the elaboration of chayote juices with stevia leaves and pineapple juice. The physicochemical properties of juice from virens levis (VL) and nigrum spinosum (NS) varieties were determined using standard methods. The juice of the two varieties differ significantly regarding the concentrations of total soluble solids, total sugars, but not vitamin C. The total concentration of phenolics in NS extracts was slightly higher than in VL (1005 and 856 mg 100 g−1 dry-weight, respectively) but the total flavonoid contents were similar (27 and 26 mg 100 g−1 dry-weight, respectively). Cucurbitacin D was predominant in both varieties. The radical scavenging capacities of VL and NS extracts varied slightly (IC50 = 0.45 to 0.65 mg mL−1), while the antioxidant activities were similar (~80%). The NS variety is particularly promising regarding nutraceutical application. The chayote juice combined with stevia and pineapple maintain the original nutraceutical characteristics from the fruit, but enhanced the organoleptic characteristics like density and sugar/acidity balance.
REVIEW | doi:10.20944/preprints202311.1889.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: polyphenols; antioxidant; functional food; anticancer; antidiabetic
Online: 29 November 2023 (12:17:34 CET)
In recent years, the evaluation of many plant-derived compounds as potential new drugs or functional foods has become an active research topic. The characteristics of quinces of the genera Cydonia, Chaenomeles and Pseuocydonia are largely similar, which is why these fruits are often confused. Although they have been appreciated in Asia for centuries as a valuable component of local ethnomedicine, they are less known in Western countries and scientific knowledge about their health benefits remains fragmentary. This literature review presents the bioactive compounds of these fruits with special emphasis on antioxidants. Most space has been devoted to the presentation of the biological activities and potential medical applications of the fruits due to their antioxidant, anti-inflammatory, anticancer, cardioprotective and antidiabetic effects.
ARTICLE | doi:10.20944/preprints202311.1599.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Perilla frutescens; extracts; antioxidant; antitumoral; cytotoxicity
Online: 24 November 2023 (11:33:48 CET)
(1) Background: This study aimed to outline the antitumoral, antioxidant, and cytotoxic proprie-ties of various types of Perilla frutescens extracts obtained from the leaves of the species; (2) Methods: We determined total polyphenols, flavonoids and anthocyanins contents, as well as the in vitro antioxidant, antitumoral, and cytotoxic actions in 3 types of ethanolic extracts (E1, E2, E3) and in 3 types of ethanol: acetone extracts (A1, A2, A3) of Perilla frutescens according to standardized procedures; (3) Results: We found that Perilla frutescens ethanolic extracts had higher total phenol concentrations (p= 0.002). Flavonoids and anthocyanins concentrations were not statistically different between the two extracts. The iron chelating capacity, hydroxyl radical scavenging capacity, superoxide anion radical scavenging capacity, and lipoxygenase inhibition capacity showed a significant increase with higher concentrations of Perilla frutescens extracts, particularly the ethanolic extracts. Perillyl alcohol had greater cytotoxic capacity on MG-63 cell line and E1 extract showed similar significant cytotoxic effects on A431 cell line; (4) Conclusions: Both ethanolic and ethanol: acetone extracts from Perilla frutescens exhibited important antioxi-dant and antitumoral actions in vitro, which proportionally increased with concentration. The cytotoxic threshold determined in this study for various types of extracts could help determine the best dosage with the maximum antioxidant and antitumoral potential.
ARTICLE | doi:10.20944/preprints202310.0655.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: Bangladeshi medicinal plants; antioxidant; anti-inflammatory
Online: 11 October 2023 (06:30:43 CEST)
Bangladeshi medicinal plants (BMP) have been used as traditional medicinal plants to treat chronic inflammatory diseases, but the antioxidant and anti-inflammatory effects of the bark of BMP are not yet known. The objective of this study was to determine antioxidant and anti-inflammatory activities using methanolic extracts of bark obtained from 15 medicinal spices of Bangladesh plants. The bark methanol extracts of BMP evaluated the total antioxidant activity and anti-inflammatory effect of lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophages. Among the 15 bark extracts of BMP, Albizia odoratissima (A. odoratissima), Engelhardia spicata (E. spicata), and Shorea robusta (S. robusta) showed the highest total phenolic contents and total antioxidant capacity by reducing free radicals scavenging activity. In particular, the three bark extracts significantly reduced the mRNA expression of LPS-induced inflammatory cytokines and inflammation-inducible enzymes in macrophages. Also, the mRNA expression of NADPH oxidase 2 was significantly suppressed by three bark extracts in LPS-induced RAW 264.7 macrophages. The results suggest that among the 15 bark extracts obtained from medicinal plant in Bangladesh, three bark extracts of A. odoratissima, E. spicata, and S. robusta exert total antioxidant capacity by reducing free radicals scavenging activity and inhibitory effects on LPS-stimulated inflammation in macrophages.
ARTICLE | doi:10.20944/preprints202305.2051.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: ecological system; pork composition; TBARS; antioxidant
Online: 30 May 2023 (05:18:07 CEST)
The aim of the study was to evaluate the impact of different rearing systems (organic, conventional and traditional) on the physicochemical properties and oxidation states of pork meat. Samples (M.biceps femoris) were obtained from producers directly 3 days after slaughtering. Chemical composition (dry matter, protein, collagen, fat, ash), colour (L*, a*, b*) and oxidation state (Thiobarbituric acid reactive substances -TBARS, free fatty acid -FFA and antioxidant capacity-2,2-diphenyl-1-picrylhydrazyl) of the meat samples were determined. The results indicated that the rearing system affects most of the evaluated parameters. The significant difference (P < 0.05) was observed in colour parameter L* and b*, where the conventional pork was darker and the organic pork yellower. Total protein content in meat of conventional pigs was higher, whereas the fat content in the meat of organically reared pigs was higher than the meat of pigs from both other rearing systems. Organic pork was more susceptible to oxidation process due to its higher TBARS and FFA values and lower antioxidant capacity, which may result in inferior technological properties of meat.
ARTICLE | doi:10.20944/preprints202305.1189.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: antioxidant; chlorogenic acid; caffeine; cytotoxicity; melanoidins
Online: 17 May 2023 (04:58:53 CEST)
: Coffee is one of the most consumed beverages in the world; its production is based mainly on varieties of the Coffea arabica species. Mexico stands out for its specialty and organic coffee. In Guerrero the production is given by small indigenous community’s cooperatives that market their product as raw material. Official Mexican Standards stipulate the necessary requirements for its commercialization within the national ter-ritory. In this work, the physical, chemical, and biological characterizations of green, medium, and dark roasted beans from C. arabica varieties were carried out. Analysis of HPLC showed higher chlorogenic acid (55 mg/g) and caffeine (1.8 mg/g) contents in the green beans of the Bourbon and Oro Azteca varieties. The caffeine (3.88 mg/g) and melanoidins (97 and 29 mg/g) contents increased according to the level of roasting; a dissimilar effect was found in the chlorogenic acid content (14.5 mg/g). The adequate nutritional content and the sensory evaluation allowed the classification of dark roasted as premium coffee (84.25 points) and the roasted medium as specialty coffee (86.25 points). The roasted coffees presented antioxidant activity without cytotoxic effect. The results obtained will serve as a basis for making decisions on the improvements of the coffees analyzed.
REVIEW | doi:10.20944/preprints202305.0665.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: carbon monoxide; hemoglobin; carboxyhemoglobin; glutathione; antioxidant
Online: 9 May 2023 (13:36:14 CEST)
Carbon monoxide (CO) is a cytoprotective endogenous gas that is ubiquitously produced by the stress response enzyme heme-oxygenase. Being a gas, CO rapidly diffuses through tissues and binds to hemoglobin (Hb) increasing carboxyhemoglobin (COHb) levels. COHb can be formed in the erythrocytes or in plasma from cell-free Hb. Herein, it is discussed whether endogenous COHb is or is not an innocuous and inevitable metabolic waste product and it is hypothesized that COHb has a biological role. In the present review literature data is presented to support this hypothesis based on two main premises: (i) there is no direct correlation between COHb levels and CO toxicity; and (ii) COHb seems to have a direct cytoprotective and antioxidant role in erythrocytes and in hemorrhagic models in vivo. Moreover, CO is also antioxidant by generating COHb, which protects against the pro-oxidant damaging effects of cell free Hb. Up to now COHb has been considered as a sink for both exogenous and endogenous CO generated during CO intoxication or heme metabolism, respectively. Hallmarking COHb as an important molecule with a biological (and eventually beneficial) role is a turning point on CO Biology research, namely in CO intoxication and CO cytoprotection.
SHORT NOTE | doi:10.20944/preprints202305.0589.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: coumarin; esculetin; ferulic acid; esterification; antioxidant
Online: 9 May 2023 (07:50:21 CEST)
A conjugate compound 5, (E)-6-hydroxy-2-oxo-2H-chromen-7-yl 3-(4-hydroxy-3-methoxyphenyl)acrylate, of 6,7-hydroxycoumarin (esculetin) 3 and (E)-3-(4-hydroxy-3-methoxyphenyl)- acrylic acid (ferulic acid) 1 was prepared in 61% yield by the esterification reaction of a protected ferulic acid 2a with esculetin 3 in the presence of triethylamine in dichloromethane for 3 h, followed by deprotection using 3M HCl. The structure of compound 5 was confirmed by 1H, 13C NMR spectroscopy, mass-spectrometry and elemental analysis.
REVIEW | doi:10.20944/preprints202302.0333.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Vitamin E; testis; sperm; antioxidant; reproduction
Online: 20 February 2023 (08:59:03 CET)
Vitamin E facilitates testicular development and semen quality in farm animal. And most research tends to investigate antioxidant roles of Vitamin E in reproductive health; some research also find potential non-antioxidant roles of Vitamin E. To further uncover the mechanism by which Vitamin E modulates reproductive health, the paper reviews specific function of Vitamin E and candidate genes involved in male reproductive performance promoted by Vitamin E. The review found that cell proliferation (PDPN, BMP, Myc, AMPKa, GSK3β, PPARγ, CDK4, CDK6, Ki67, PCNA, Cyclin A2, Cyclin B1, Cyclin B3, BLM, REL, KLHL25)-, cell apoptosis (BCL-2, Caspase 9, Bax)-, spermatogenesis (CatSper1, CatSper2, NDRG1, CYP26B1, FSCN3, FLNA, SPCS3, YBX3, RARS)-, hormone receptor (PGR, FSHR, AR)-related genes are the underlying key points. And two miRNAs, miR-107 and miR-493-3p, which mediate cell cycle process, are also identified in response to Vitamin E treatment. The paper paves the way for a comprehensive understanding about effect of Vitamin E on testis development and semen quality in domestic animals.
REVIEW | doi:10.20944/preprints202301.0321.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: Anti-inflamotry; antioxidant; oxidative stress; zebrafish
Online: 18 January 2023 (07:06:34 CET)
This work is based on identifying the analysis techniques used to evaluate the antioxidant and anti-inflammatory effects using the zebrafish model. In this context, a literature review was performed with the Web of Science database. We used the terms zebra fish, antioxidant, anti-inflammatory, model, and Danio rerio. Fifty articles were reviewed, of which thirty-three were chosen to perform this review and were classified according to the source of plant extracts, compounds extracted from plants, chemical compounds, and other sources. This paper is an effort to provide a literature review on zebrafish models and elucidate their pros and cons to evaluate anti-inflamatory and antioxidant activity.
REVIEW | doi:10.20944/preprints202205.0197.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Natural product; bioactive compounds; antimicrobial; antioxidant
Online: 16 May 2022 (05:07:30 CEST)
Natural compounds have diverse structures and are present in different forms of life. Metabolites such as tannins, anthocyanins, and alkaloids, among others, serve as a defense mechanism in live organisms and are undoubtedly compounds of interest for the food, cosmetic and pharmaceutical industries. Plants, bacteria, and insects represent a source of biomolecules with diverse activities, poorly studied in many cases. To use these molecules for different applications, it is essential to know their structure, concentrations, and biological activity potential. In vitro techniques that evaluate the biological activity of the molecules of interest have been developed since the 1950s. Currently, different methodologies have emerged to overcome some of the limitations of these traditional techniques, mainly the reduction of time and costs. However, emerging technologies continue to appear due to the urgent need to expand the analysis capacity of a growing number of reported biomolecules and the lack of therapeutic options to treat various diseases. This review presents an updated summary of the conventional and current methods to evaluate natural compounds' biological activity, including a diagram that summarizes the minimum techniques essential for correctly assessing molecules with biological potential.
ARTICLE | doi:10.20944/preprints202008.0541.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: antioxidant activity; dietary supplements; microalgal cultivation
Online: 25 August 2020 (08:41:14 CEST)
Microalgae production is expensive and demands high volumes of water and energy to meet all market demands and yet the production of secondary metabolites using alternative media needs deeper studies. Among alternative media, the use of sugar cane vinasse has gained attention for microalgae cultivation. In this work, we’ve compared the biomass yield and secondary metabolites of Chlorella sorokiniana grown in a commercial medium (Sueoka) and in alternative medium prepared with cane vinasse (0.1%) supplemented with N, P2O5 and K2O (commercial formula 20-5-20 g.L-1). The production of microalgae biomass grown in an alternative medium was 2.2% lower, but reached its maximum growth point 14 days faster than the commercial medium. The average level of Phenolic compounds on the commercial medium were 6.02 ± 0.13 mg GAE .g-1 and increased to 15.28 ± 0.32 mg GAE.g-1when C. sorokinianawere grown in the vinasse medium. Same how, Flavonoids contents varied from 13.12 ± 1.33 to 72.30 ± 5.28 mg QE. g-1 to commercial and vinasse medium, respectively. The maximum AOA of C. sorokiniana grown in vinasse medium was 88.05% at a concentration of 1500 µg.mL-1 of extract, with IC50 at 357.7 ± 27.35 µg.mL-1. Different factors seem to induce variances on secondary metabolites synthesis, mostly stress due to QOD and ions added to the medium by vinasse. The authors recognize there are more investigations to be done, but increasing a natural and low cost pathway for flavonoids yield open up an interesting field for the bioprospection of microalgae.
Subject: Biology And Life Sciences, Aging Keywords: astaxanthin; antioxidant; skin; ultraviolet; photoaging; capillary
Online: 20 January 2020 (09:55:03 CET)
Abstract: Ultraviolet (UV) induces skin photoaging, which is characterized by thickening, wrinkling, pigmentation, and dryness. Astaxanthin, a ketocarotenoid from Haematococcus pluvialis, has been extensively studied with respect to its possible effect on skin health as well as UV protection. In addition, astaxanthin attenuates increases in the generation of reactive oxygen species (ROS) and capillary regression of skeletal muscle. In the present study, we investigated whether astaxanthin would protect UV-induced photoaging and capillary regression in the skin of HR-1 hairless mice. UV induces wrinkle formation, thickness and capillary regression in dermis of hairless mice and the administration of astaxanthin decreased the UV-induced wrinkle formation, skin thickness, and increase in collagen fibers in skin. Astaxanthin supplementation also inhibited the levels of ROS generation and attenuated the decreases in wrinkle formation, thickness and capillary number in the skin. We also found an inverse correlation between wrinkling and capillary number, and the photoaging associated with capillary regression in skin. These results suggest that astaxanthin can protect against photoaging caused by ultraviolet irradiation and the effects of astaxanthin in photoaging inhibition may be associated with the protection of capillary regression in skin.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Pseudoalteromonas；proteases；hydrolysis；collagen；antioxidant peptides
Online: 24 July 2019 (11:56:00 CEST)
In this study, an extracellular metalloprotease from Pseudoalteromonas sp. H2 was purified and identified. The EH2 maintained more than 80% activity over a wide pH range of 5-10 and the stability was also nearly independent of pH. More than 65% of activity was detected in a wide temperature of 20-70℃. The high stability of the protease in presence of different surfactants and oxidizing agent was also observed. Moreover, we also investigated the antioxidant activities of the hydrolysates generated from porcine and salmon skins collagen by EH2. The results show that salmon skins collagen hydrolysates demonstrated higher DPPH (42.88%±1.85) and hydroxyl radical (61.83%±3.05) scavenging activity compared to those produced with porcine skins collagen. For oxygen radical absorbance capacity, the hydrolysates from porcine skins collagen had higher efficiency (7.72±0.13 μmol·TE/μmol). Even 1 nM mixed peptides can effectively reduce the levels of intracellular ROS. And the two type of substrates exerted the best antioxidant activity when hydrolyzed for 3 hours. Hydrolysis time and type of substrate exerted important effect on the antioxidant property of hydrolysates. This study may have implications for the potential application of marine protease in biocatalysis industry. In addition, the hydrolyzed peptides from meat waste containing beneficial collagen by protease have good antioxidant activity indicating it may be a potential additive in the food processing industry and cosmetics industry.
REVIEW | doi:10.20944/preprints201811.0189.v4
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: beta-alanine; carnosine; oxidative stress; antioxidant
Online: 28 December 2018 (04:39:00 CET)
The objective of this study was to perform a systematic review and meta-analysis of the articles that addressed the effect BA or carnosine supplementation on physical exercise (PE)-induced oxidative stress (OS). Before May 2018 we searched throughout PubMed, CAPES Periodic and SPORTDiscus human model peer review, randomized control studies with chronic BA or carnosine supplementation on PE-induced OS. A total of 128 citations were found. Only four articles met criteria for inclusion. All four studies used healthy young sedentary, recreationally active or athletic participants. After a chronic BA or carnosine supplementation, the studies evaluated PE-induced OS both immediately and several hours after exercise (0.5 to 48 h). In response to PE-induced OS, when compared to placebo, BA/carnosine supplementation increased total antioxidant capacity [TAC; Effect Size (ES) = 0.35, 95% Confidence Interval (CI) 0.06 to 0.65, p = 0.02] and glutathione (GSH; ES = 0.75, 95% CI 0.32 to 1.19, p = 0.0007) concentrations while decreased direct OS markers (ES = −1.19, 95% CI −1.48 to −0.80, p < 0.01) and superoxide dismutase (SOD) activity (ES = − 0.58, 95% CI −1.10 to −0.06, p = 0.03). BA or carnosine supplementation did not prevent the increase in indirect OS markers (ES: 0.06, 95% CI −0.38 to 0.500, p = 0.80). In humans, following PE-induced OS, initial treatment trials of BA or carnosine supplementation seemed to increase TAC and GSH concentrations, while decreasing SOD activity. Also, albeit mitigating the acute increase in direct OS markers (reactive nitrogen and oxygen species), treatment did not decrease measured values of indirect OS markers (peroxidation or molecule oxidation).
ARTICLE | doi:10.20944/preprints201811.0011.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: thiazolyl dyes; anticancer; antioxidant; colour assessment
Online: 2 November 2018 (04:28:50 CET)
This work is aiming to motivation on the prospect of evolving new thiazole dyes with respectable application properties, expected pharmacological activities. Curcumin Coupling with diverse diazonium salts of 2-amino thiazole derivatives as 2-aminobenzothiazole, 2- amino-5-phenylthiazole, 2 amino-5-methylthiazole and 2 amino-5-nitrothiazole to produce novel azo dyes. All synthesised dyes were completely confirmed their structures via elemental and spectroscopic techniques. The synthesised thiazole derivatives were examined for their “antimicrobial, anticancer and antioxidant” activities. All of the synthesized dyes were applied on synthetic fabrics as polyester and successively their dyeing properties, “light, washing, perspiration, rubbing and sublimation” fastness were evaluated. Prepared dyestuffs are suitable for dyeing polyester fabrics. It was initiate that all of prepared dyes own extraordinary colour hue, along with respectable fastness properties. Also the synthesised thiazole derivatives display moral pharmacology activity.
ARTICLE | doi:10.20944/preprints201810.0553.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Cucumis sativus; nutraceutical; antioxidant; ABTS+, DPPH+
Online: 24 October 2018 (06:30:43 CEST)
The objective of this research was to evaluate the production and phytochemical quality of cucumber fruits (Cucumis sativus), in response to the foliar application of different seaweed extracts. This study was carried out under shadow mesh conditions in the autumn - winter agricultural cycle at Instituto Tecnológico de Torreón, Torreón, Coahuila. The experimental design was completely random, using six treatments with six repetitions each. The treatments evaluated were: Macrocystis pyrifera, Bryothamnion triquetrum, Ascophyllum nodosum, Grammatophora sp., Macrocystis intergrifolia, and a control treatment with inorganic fertilization. The substrate used was a mixture of sand and vermicompost. The yield, commercial quality and phytochemical compounds of the fruit were evaluated. Results showed that yield using Steiner solution (6.75 kg m−2) was higher than that obtained with Bryothamnion triquetrum algae (6.07 kg m−2). Regarding the phenolic content, the extracts surpassed the control treatment, with Macrocystis pyrifera and Macrocystis integrifolia being statistically equal, with values of 47.37 and 43.73 mg equiv. of Ac. Gallic 100 g fresh weight, respectively. The antioxidant capacity by ABTS+ and DPPH+ methods was higher using the treatment with algae Macrocystis pyrifera with 149.4 and 454.1 μM equiv Trolox/100 g fresh base, respectively. This treatment also presented the highest value of vitamin C with 5.07 mg/100 g fresh base, being 27% greater than the control treatment. Algae extracts increased the quality of the fruits by obtaining the highest antioxidant capacity, making their use a viable option to minimize the application of conventional fertilizers, thereby attenuating the effects on the environment and improving the health of the population.
ARTICLE | doi:10.20944/preprints201805.0064.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: finger millet; mycorrhiza; drought; ROS; antioxidant
Online: 3 May 2018 (09:38:17 CEST)
Under abiotic stress conditions, arbuscular mycorrhizal (AM) fungi help plants by improving nutrient and water uptake. Finger millet is an arid crop having soils with poor water holding capacity. Therefore, it is difficult for the plants to obtain water and mineral nutrients from the soil to sustain life. To understand the role of mycorrhizal symbiosis in water and mineral up-take from the soil, we studied the role of Rhizophagus intraradices colonization and its beneficial role for drought stress tolerance in finger millet seedling. Under severe drought stress condition, AM inoculation led to the significant increase in plant growth (7%), phosphorus, and chlorophyll content (29%). Also, the level of osmolytes including proline and soluble sugars were found in higher quantities in AM inoculated seedlings under drought stress. Under water stress, the lipid peroxidation in leaves of mycorrhized seedlings was reduced by 29%. The flavonoid content of roots in AM colonized seedlings was found 16% higher compared to the control, whereas the leaves were accumulated more phenol. Compared to the control, ascorbate level was found to be 25% higher in leaf tissue of AM inoculated seedlings. Moreover, glutathione (GSH) level was increased in mycorrhiza inoculated seedlings with a maximum increment of 182% under severe stress. The results demonstrated that AM provided drought tolerance to the finger millet seedlings through a stronger root system, greater photosynthetic efficiency, a more efficient antioxidant system and improved osmoregulation.
ARTICLE | doi:10.20944/preprints201705.0106.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: propolis; NIR spectroscopy; flavonoids; antioxidant capacity
Online: 12 May 2017 (05:53:14 CEST)
Propolis is a bee product widely used as a dietary supplement and included in sweets or baby foods due to its well-known antioxidant and nutritional properties that are directly correlated with its phenolic composition. For this reason, this study analysed the total contents of flavones and flavonols, flavanones and dihydroflavonols, and the antioxidant capacity by using the methods of ABTS and linoleic acid/β-carotene in 99 samples of propolis from Spain and Chile. A rapid method was developed for quantifying these parameters in raw propolis using near infrared (NIR) spectroscopy with an optical fibre probe of remote reflectance applied directly to the ground up sample. The models developed allow the determination of the total of flavones and flavonols (0-183 mg rutin/ g propolis), of the total of flavanones and dihydroflavonols (9-109 mg pinocembrin/ g propolis extract), and the antioxidant capacity by the ABTS method (0-3212 nmolesTrolox/ mg of propolis) and of linoleic acid/β-carotene (22-86% inhibition). The NIR spectroscopy models were applied in external validation to different samples of the calibration group, which led to the conclusion that the methods developed provide significantly identical data to the initial chemical data of reference.
ARTICLE | doi:10.20944/preprints201610.0083.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: stroke; antioxidant; co-drug; animal model
Online: 20 October 2016 (08:46:38 CEST)
Background: Previously, our laboratory has provided evidence that pre-administration of the antioxidant, lipoic acid covalently bonded to various naturally occurring antioxidants, enhanced neuroprotective capacity compared to the administration of lipoic acid on its own. The naturally occurring compound scopoletin, a coumarin derivative, has been shown in various in vitro studies to have both antioxidant and anti-inflammatory mechanism of actions. To date, the effect of scopoletin on neuronal cell death in an in vivo model of ischemia or ischemia-reperfusion has not been investigated. Therefore, the present investigation was designed to determine if scopoletin on its own, or a co-drug consisting of lipoic acid and scopoletin covalent bond, named UPEI-400, would be capable of demonstrating a similar neuroprotective efficacy. Methods: Using a rodent model of stroke in male rats (anesthetized with Inactin®; 100 mg/kg, iv), the middle cerebral artery was permanently occluded for 6 hours (pMCAO), or in separate animals, occluded for 30 min followed by 5.5 hrs of reperfusion (ischemia/reperfusion; I/R). Results: Pre-administration of either scopoletin or UPEI-400 significantly decreased infarct volume in the I/R model (p<0.05), but not in the pMCAO model of stroke. However, UPEI-400 was ~1000 times more potent as compared to scopoletin on its own. The optimal dose of UPEI-400 was then injected during the occlusion and at several time points during reperfusion and significant neuroprotection was observed for up to 150 mins following the start of reperfusion (p<0.05). Conclusion: The data suggest that synthetic combination of scopoletin with lipoic acid (UPEI-400) is a more effective neuroprotectant that either compound on their own. Also, since UPEI-400 was only effective in a model of I/R, it is possible that it may act to enhance neuronal antioxidant capacity and/or upregulate anti-inflammatory pathways to prevent the neuronal cell death.
ARTICLE | doi:10.20944/preprints202311.1368.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Empetrum rubrum; Antioxidant; Antifungal activity; HPLC-MS
Online: 22 November 2023 (03:43:26 CET)
In searching for compounds with antioxidant and antifungal activity, our study focused on the subshrub species Empetrum rubrum Vahl ex Willd. (Ericaceae), commonly known as Brecillo or Murtilla de Magallanes. We measured the antioxidant activity of its methanolic extract (MEE) obtained from the aerial parts (leaves and stems). The antioxidant activity of MEE was evaluated in vitro by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cationic radical. Results were expressed in gallic acid and Trolox equivalents for DPPH and ABTS assays, respectively. The antioxidant activities, for the DPPH and ABTS assays, were also calculated as an inhibitory concentration of extract needed to inhibit 50% of the absorbance (IC50 value). The results of IC50 values measured by the DPPH and ABTS methods were 0.4145 mg mL-1 and 0.1081 mg mL-1, respectively. In relation to the antioxidant activity, the total phenolic content (TPC) in MEE was determined by the Folin-Ciocalteu method, and the presence of secondary metabolites groups, including phenolic compounds, was determined by using different standardized test procedures. Phenolic compounds contained in leaves, stems, and fruits of E. rubrum were determined qualitatively by means of high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) analysis. The antifungal activity of MEE obtained from aerial parts of E. rubrum was tested against Rhizoctonia solani. In vitro, mycelial growth of this fungus was reduced from 90% to 100% in the presence of MEE.
ARTICLE | doi:10.20944/preprints202311.0207.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Blood groups; Antioxidant; erythroprotective potential; oxidative-stress
Online: 3 November 2023 (11:16:34 CET)
Previous studies detail that the different blood groups are associate to incidence of oxidative stress-related diseases such as certain carcinomas. Bioactive compounds represent an alternative to prevent this oxidative-stress. The aim of this study was to elucidate the impact of blood groups on the erythroprotective potential of Fucoxanthin, β-Carotene, gallic acid, quercetin, and ascorbic acid as therapeutic agents against oxidative-stress. The impact of ABO blood groups on the erythroprotective potential was evaluate by the elucidated antioxidant capacity, blood biocompatibility, blood susceptibility and erythroprotective potential (membrane stabilization, in vitro photostability and antihemolytic activity). All antioxidant tested exhibited a highest potent antioxidant capacity and presented the ability to inhibit ROO•-induced oxidative-stress without compromising the cell membrane, providing an erythroprotective effect dependent on the blood group. Effect that increased in the presence of antigen A. This result could be key to the prevention of carcinomas associated with antigen A, such as breast and skin cancer. These results revealed a probable relationship between the different erythrocyte antigens with the erythroprotective potential, highlighting the importance of bio-targeted drugs for groups mostly susceptible to certain chronic-degenerative pathologies. These compounds could be applied as additive, nutraceutical or encapsulated to improve its bioaccessibility.
ARTICLE | doi:10.20944/preprints202310.1773.v1
Subject: Medicine And Pharmacology, Pharmacy Keywords: Obesity; Diabetes; Ficus carica L.; Phytochemicals; Antioxidant
Online: 27 October 2023 (10:26:21 CEST)
Utilization of medicine derived from plants has been documented in various traditional systems of medicines throughout the world for different diseases. Therefore, the current research work was carried out to evaluate the phytochemical and biological potential of Ficus carica L ethanolic leaf extract. For this purpose, physicochemical and phytochemical analysis, total phenolic and flavonoids contents was performed. Antioxidant potential was determined by FRAP, DPPH and H2O2 assay. Proteinase inhibition, heat induced hemolysis and BSA denaturation assay was carried out for inflammation. Antiglycation potential was assessed by fructosamine assay, Congo-red assay and estimation of free carbonyl groups. In-vivo antidiabetic, anti-obesity, effect on liver and kidney were investigated by high fat high sugar diet model. FTIR, HPLC and LCMS/MS analysis was performed to find out the compounds. Tablet based formulation was developed using wet granulation method and tested for physicochemical parameters. Results shows that total phenolic and flavonoids content was (333 mg GAE/g) and (123 mg RE/g) respectively, H2O2 assay shows 35.6% free radical inhibition potential, DPPH assay shows (IC50) inhibitory concentration at 0.58 mg/mL, and 88.769 µg/g Fe2SO4 solution FRAP values. Proteinase inhibition assay, Heat induced hemolysis and BSA-denaturation assay shows percentage inhibition of 28 ± 0.01, 55 ± 0.03 and 51.2 ± 0.05 respectively. In Antiglycation activity β-amyloid formation assay shows absorption of 0.017, Fructosamine assay shows inhibition of 19.4±0.06 and free carbonyl group estimation shows inhibition of 17.0±0.03. In in-vivo study FLE at (500 mg/kg) significantly decreased total bilirubin (p ≤ 0.001), decreased (p ≤ 0.05) alanine transferase, aspartate aminotransferase, alkaline phosphatase, decreased blood glucose, triglycerides and total cholesterol (p ≤ 0.01) while HDL (p ≤ 0.01) was significantly increased in comparison to obesity and diabetic-obesity groups. Different functional groups presence was confirmed by FTIR spectrum. HPLC analysis revealed the existence of ferulic acid, rutin, chlorogenic acid, coumarin and thymoquinone and these results are corelated by LC-MS/MS. Pre-compression characterization showed angle of repose (33.04°), bulk density (0.54 g/cm3), tapped density (0.73 g/cm3), compressibility index (35.179 %) and Hausner’s ratio (1.35), while the post-compression characterization showed weight variation 826±4.17 mg, thickness 10.50±0.25 kg/cm2, friability 0.57 %, and disintegration time 8.19 min. From the above results it is concluded that F. carica L. leaves extract has strong antioxidant, antidiabetic and hypolipidemic potential and can be used for an obesity and diabetes treatment.
ARTICLE | doi:10.20944/preprints202310.1422.v1
Subject: Biology And Life Sciences, Parasitology Keywords: Lycopene; N-Acetylcysteine; Malaria; Oxidative stress; Antioxidant
Online: 23 October 2023 (15:23:27 CEST)
(1) Background: The severity of malaria is associated with low bioavailability of antioxidants and high concentration of free radicals that induce oxidative damage in cerebral and pulmonary microcirculation. This can be prevented by the action of consumable antioxidants present in foods. Therefore, we investigated the protective role of lycopene (LYC) on the oxidative changes induced by Plasmodium berghei (Pb); (2) Methods: Mice were infected by intraperitoneal injection of 106 parasitized red blood cells and treated via gavage with LYC (3.11 mg/kg bw/day) or NAC (62 mg/kg bw/day). They were then evaluated for 1, 4, 8 or 12 days after infection. Levels of thiobarbituric acid reactive substances (TBARS), antioxidant capacity by inhibition of ABTS radicals (AC-ABTS) and DPPH (AC-DPPH), uric acid (UA), and nitric oxide (NO) were measured in brain and lung tissues; (3) Results: The infection caused oxidative stress confirmed by increased levels of TBARS, AC-ABTS, AC-DPPH, UA, and NO in the tissues leading to the death of the animals. LYC prevented the increase in TBARS, AU, and NO levels compared to Pb (p< 0.0001) and NAC+Pb groups (p<0.0001), reaching values similar to those of Sham animals; (4) Conclusions: These results are striking evidence of the beneficial effect of lycopene supplementation on oxidative stress in experimental malaria in vivo and emphasize the importance of antioxidant supplementation in the treatment of the disease.
ARTICLE | doi:10.20944/preprints202310.0735.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: : theobroma cacao; bromatological; phenolic compounds; antioxidant activity
Online: 11 October 2023 (13:22:01 CEST)
Cocoa bean quality depends mainly on genetic material, edaphoclimatic factors and post-harvest processes such as fermentation. The impact of the fermentation process on the chemical and func-tional composition of different cocoa clones grown in southern Colombia was analyzed. A facto-rial design with repeated measures over time was used to analyze the effect of clone and fermen-tation time on chemical characteristics (bromatology, phenolic compounds and antioxidant ac-tivity). The bromatological characteristics showed significant differences between clones and fermentation time. Clones EET-8 and CCN-51 showed higher contents of acidity (0.51%), fat (63.61%), protein (12.85%) and carbohydrates (1.63 mg g-1). Moisture, acidity and sucrose in-creased their values between day 4 and day 6 of fermentation (P<0.05). Phenolic compounds and antioxidant activity had significant differences between clones, where clones CCN-51 and ICS-95 had high contents of phenols (64.56 mg g-1), flavonoids (3.30 mg g-1) and DPPH reducing capacity (325.55 µmol g-1). In this sense, we consider the FSV-41 clone as the major grain quality index based on the results of chemical composition at bromatological level, antioxidant activity and phenolic compounds.
ARTICLE | doi:10.20944/preprints202310.0149.v1
Subject: Biology And Life Sciences, Horticulture Keywords: abiotic stress; antioxidant system; drought; jasmonates; photosynthesis
Online: 3 October 2023 (10:41:41 CEST)
The plant water status is crucial for growth and production, but the current climate change scenario makes it challenging to match the water plant demand. Blueberry is an economically important crop and plays an acknowledged role in human health due to its antioxidant compounds. This research aimed to determine whether exogenous methyl jasmonate application improves the antioxidant defense mechanisms for protecting the photosynthetic performance in blueberry plants under the stress condition of water deficit. A greenhouse experiment was carried out under a 16-h light period; 20ºC; and 60-80% relative humidity for 2 weeks before treatment application of methyl jasmonate (MeJA) to blueberry plants (Vaccinium corymbosum, Brigitta cultivar). The following treatments were maintained for 7-days: (i) 80% field capacity (NoWD); (ii) 80% field capacity plus MeJA application (NoWD + MeJA); (iii) 20% field capacity (WD); and (iv) 20% field capacity plus MeJA application (WD + MeJA). The MeJA was sprayed as an aqueous solution of 10 µM MeJA (Sigma-Aldrich) over the plant's foliar system. At the end of the assay; blueberry leaves were analyzed for the relative water content; specific leaf area; lipid peroxidation; total antioxidant activity; total phenols; total anthocyanins; anthocyanidin compounds and photosynthetic performance. Brigitta cultivar showed a significant decrease in the oxidative stress at leaf levels; with an increase in antioxidant activity; phenolic compounds; total anthocyanins; delphinidin; petunidin; antheraxanthin; zeaxanthin; and an improvement in photosynthetic performance parameters. Blueberry Brigitta cultivar was shown to be susceptible to WD decreased mainly photosynthesis. However; the MeJA application on leaves induced metabolic changes; through an increase of antioxidant strategy within the plant to counteract the negative effects of WD; protecting the photosynthetic apparatus; which allows the Brigitta cultivar to withstand the period of WD.
ARTICLE | doi:10.20944/preprints202309.1524.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: 1,2,3-triazoles; antioxidant; lanthanum; vibrational analysis; scaling
Online: 22 September 2023 (09:20:38 CEST)
The 1,2,3-triazole derivative 2-(4-chlorophenyl)-5-(pyrrolidin-1-yl)-2H-1,2,3-triazole-4-carboxylic acid with potential anticancer activity was used as a ligand in complex formation with the lan-thanum(III) ion. The molecular structure and vibrational spectra of the complex were optimized at three DFT levels and the scaled IR and Raman spectra were compared to the experimental ones. Several scaling procedures were used. Through a detailed analysis, the structure predicted for the newly synthetized La(III) complex was confirmed by the good accordance of the calculat-ed-experimental IR and Raman spectra. The best DFT method appears to be M06-2X with the Lanl2mb basis set, followed closely by Lanl2dz. The effect of the lanthanide atom on the molecular structure and atomic charge distribution of the triazole ring was evaluated. Potential free radical scavenging activity of both, ligand and complex, was investigated in several radical-generating model systems. Potential mechanisms of antioxidant action (hydrogen atom transfer – HAT and single electron transfer - SET) were elucidated.
COMMUNICATION | doi:10.20944/preprints202306.2148.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: Curcumin-Copper (II); single crystal; cytotoxicity; antioxidant
Online: 29 June 2023 (13:26:13 CEST)
The first single crystal structure of the homoleptic copper (II) ML2 complex (M=Cu (II), L=curcumin) was obtained and its structure was elucidated by X-ray diffraction showing a square planar geometry. The supramolecular arrangement is supported by C-H···O interactions and the solvent (MeOH) plays an important role in stabilizing the crystal packing. The cytotoxic activity of the complex against six cancer cell lines substantially surpasses that of curcumin itself, and it is particularly selective against leukemia (K562) and human glioblastoma (U251) cell lines with similar antioxidant activity to BHT. This constitutes the first crystal structure of pristine curcumin complexed with a metal ion.
ARTICLE | doi:10.20944/preprints202209.0437.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Semen; hesperidin; cryopreservation; oxidative stress; antioxidant; ram
Online: 28 September 2022 (09:35:03 CEST)
We conducted this study to determine the potential cryopreservative effects of different hesperidin (vitamin P; HSP) doses on ram semen after freeze-thawing. Semen samples were obtained from Sönmez rams by an artificial vagina. The samples were divided into six groups: control, 10, 50, 100, 250, and 500 µg/mL HSP (C, HSP10, HSP50, HSP100, HSP250, and HSP500, respectively). At the end of the study, sperm motility and kinetic parameters, plasma membrane acrosome integrity (PMAI), high mitochondrial membrane potential (HMMP), viability, lipid peroxidation levels (LPL), chromatin damage, oxidant parameters, and antioxidant parameters were assayed. None of the doses of HSP added to the semen extender showed any enhancing effect on progressive motility compared to C (p>0.05). In fact, HSP500 had negative effects (p<0.05). Moreover, PMI activities were the highest at the HSP10 dose, while LPL values were the lowest (p<0.05). The doses of HSP10 and HSP50 added to the Tris extender medium showed positive effects on spermatozoon chromatin damage. Consequently, we can say that HSP doses used in this study are not effective on semen progressive motility, but the HSP10 dose is effective on PMAI and chromatin damage by reducing LPL.
REVIEW | doi:10.20944/preprints202108.0200.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: antioxidant; anti-inflammatory; cardiovascular; Channa striatus; diabetes
Online: 9 August 2021 (14:59:08 CEST)
Diabetes mellitus remains a major risk factor for developing cardiovascular diseases, resulting in increased morbidity and mortality associated with cardiovascular complications. Given the burden of diabetes-related cardiovascular complications, there is a need to identify strategies, safe and effective therapeutic agents that could effectively prevent and control diabetes. Presently, many patients living with diabetes depends on traditional medicines as an alternative cure. Channa striatus (Haruan) is a freshwater fish traditionally used to treat wounds, inflammations, and pains. Several pharmacological investigations have supported the folkloric claims of C. striatus extracts, including hypoglycemic, hypolipidemic, antioxidant, anti-inflammatory, and pro-platelet aggregation activities. The therapeutic potentials of C. striatus were demonstrated to be associated with the presence of high content essential amino acids and good fatty acids known to improve cell growth and facilitate wound healing. Therefore, C. striatus bioactive compounds have great potentials to serve as lead candidates in developing novel therapeutic agents for the management of diabetes and related cardiovascular diseases. This review aims to provide a comprehensive overview of the pharmacological properties and therapeutic potentials of C. striatus for the management of diabetes and associated cardiovascular complications.
ARTICLE | doi:10.20944/preprints202106.0395.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Aloe Vera; cake; minerals; polyphenol; antioxidant; texture.
Online: 15 June 2021 (11:04:27 CEST)
Aloe Vera leaves have a great potential as an economic supplement with an adequate nutritional profile. In this study, Aloe Vera leaf gel (AVG) powder was used to fortify plain cakes. Freeze drying of AVG was performed for the production of Aloe Vera powder (ALP) and four plain cakes were prepared with different proportions of ALP for further investigation. Analysis suggested that ALP contained significantly (p<0.05) higher amount of protein (22.23 vs 12.24), ash (19.83 vs 0.64) and iron (175 vs 3.05) content than refined wheat flour (RWF). ALP also contained significant amount of total polyphenols and antioxidant. Moisture, protein, ash, weight, and minerals (Fe, Ca) content were higher (p<0.05) in ALP-cakes; whereas fat, volume, specific volume, height, baking loss, and total carbohydrate content were higher (p<0.05) in RWF-cakes. Incorporation of 6 and 8% ALP in the formulation increased the total polyphenols and anti-oxidant activity in plain cakes. Texture analysis revealed that hardness and chewiness increased in ALP-cakes but decreased in RWF-cakes, however, cohesiveness, springiness, and chewiness decreased in ALP-cakes. Sensory attributes suggested that 4% ALP incorporated cake was attributed as the best formulation. In conclusion, ALP can be supplemented in cakes up to 8% to improve the nutrient value.
ARTICLE | doi:10.20944/preprints202103.0742.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Salinity; wheat; organellar antioxidant; SOS pathway; RBOH
Online: 30 March 2021 (13:49:12 CEST)
The response of salt tolerant wheat genotype (Kharchia 65), and sensitive cultivars (HD2687, HD2009, WL711) to vegetative stage salinity stress (for 4 weeks) were studied at 1.1 (control), 9.1 (S1) and 14.2 (S2) dSm-1 salinity levels. Based on relative change in Membrane stability, PSII efficiency, retention of chlorophyll and carotenoid contents, Kharchia 65 showed better tolerance to salinity than other genotypes considered. To understand the role of different component mechanisms, expression of genes involved in ion exclusion, antioxidant defence and compatible osmolyte synthesis were analysed. Expression of SOS1 (plasma membrane Na+/H+ antiporter), NHX (vacuolar Na+/H+ antiporter), Ionic (sodium exclusion) and tissue tolerance (Sodium compartmentation, compatible solute accumulation and antioxidant defence) mechanisms were analysed in leaves of the genotypes after 4 weeks of salinity stress. Expression assay and the content of respective constituents indicated that apart from the well-known ion exclusion ability, Kharchia 65 also showed high level of tissue tolerance resulting in high early vigour and maintenance of growth rate afterwards. In Kharchia 65, sensing of salinity stress at plasma membrane activates NADPH Oxidase (RBOH) genes and generate ROS at apoplast. Apoplastic ROS triggers calcium influx and activates calcium signaling genes of SOS pathway (SOS1 and NHX). ROS generated from organelles chloroplast, peroxisome and mitochondria triggers cellular oxidative burst. ROS and calcium activates MAPK genes and downstream transcription factors, NAC and bZIP. MAPK signaling induces cellular antioxidant and compatible osmolyte biosynthesis and imparts tissue tolerance to salinity.
REVIEW | doi:10.20944/preprints202101.0025.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Astaxanthin; natural antioxidant; bacteriocins; hispidin; oxidative stress
Online: 4 January 2021 (12:15:33 CET)
Oxidative stress is an elevated intracellular level of free oxygen radicals that cause lipid peroxidation, protein denaturation, DNA hydroxylation, and apoptosis, ultimately negotiating cells viability. Antioxidants can scavenge such free radicals, thus reducing the oxidative stress and eventually prevent cellular damage. Medicinal plants, fruits, and spices remain the prioritized sources of antioxidants and antimicrobial properties since the time immemorial, but in contrast to plants, microorganisms can be grown at a faster rate under controlled conditions. They are non-toxic, non-carcinogenic, and biodegradable as compared to synthetic antioxidants. Microorganisms including actinomycetes, archaea, bacteria, protozoa, yeast, and fungi are auspicious source of vital bioactive compounds. The list comprises ample of bioactive components from microorganisms. One of them is bacteriocins, which are ribosomally synthesized antimicrobial peptides product of Eurotium sp., Streptomyces parvulus, S. thermophiles, Lactococcus lactis, etc. It has a great potential as next-generation antibiotics targeting the multiple-drug resistant pathogens. Pneumocandins are antifungal lipohexapeptides derived from the fungus Glarea lozoyensis, and inhibit 1,3-β-glucan synthase of the fungal cell wall and act as a precursor for the synthesis of caspofungin. It is widely used against invasive fungal infections and has been recently approved by the FDA. Taxol (paclitaxel), a chemotherapeutic drug derived from the bark of Taxus brevifolia can also be produced by endophytic fungi Taxomyces andreanae and Nodulisporium sylviforme. It is known to inhibit several fungi such as Pythium, Aphanomyces and Phytophthora. Hispidin and its derivate isolated from P. hispidus, reduce inducible nitric oxide synthase (iNOS) expression, obstruct the transcriptional activity of NF-κB, and also decrease the production of reactive oxygen species (ROS) in macrophages. Astaxanthin, known as an “aquatic” carotenoid produced by H. pluvialis, also has excellent ROS quenching activity. This study mainly focuses on fascinating antioxidant and antimicrobial compounds that have been scarcely investigated in microorganisms and discuss the promise and challenges of microorganisms as providers of health benefits.
ARTICLE | doi:10.20944/preprints202003.0090.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: biostimulant; plant defence; mushrooms; antioxidant; septoriosis; wheat
Online: 5 March 2020 (12:08:56 CET)
The Septoria Leaf Blotch Complex (SLBC), caused by the two ascomycetes Zymoseptoria tritici and Parastagonospora nodorum, can reduce global yearly yield of wheat by up to 50%. In the last decade in Italy, SLBC incidence has increased; notably, durum wheat has proven to be more susceptible than common wheat. Field fungicide treatment can efficiently control these pathogens, but it leads to the emergence of resistant strains and adversely affects human and animal health, and the environment. Our previous studies indicated that active compounds produced by Trametes versicolor can restrict the growth of mycotoxigenic fungi and the biosynthesis of their secondary metabolites (e.g. mycotoxins). Specifically, we identified Tramesan: a 23 KDa -heteropolysaccharide secreted by T. versicolor that acts as a pro-antioxidant molecule in animal cells, fungi, and plants. Foliar-spraying of Tramesan (3.3 µM) in SLBC-susceptible varieties of durum significantly diminished symptoms of Stagonospora Nodorum Blotch (SNB) and Septoria Tritici Blotch (STB) by 75% and 65%, respectively. Tests were conducted under controlled conditions as well as in field. We show that Tramesan elicits wheat defence against SNB and STB augmenting the synthesis of defence-related hormones, notably JA and SA, that in turn switch on the expression of markers of defence (PR1, PR4 inter alia). In field experiments, yield of durum wheat plants treated with Tramesan was similar to that of untreated ones. The results suggest the use of Tramesan for protecting durum wheat against SLBC.
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: antimicrobial; antioxidant; bioprospecting; lapachol; Tabebuia aurea; toxicity
Online: 22 January 2020 (02:41:05 CET)
Tabebuia aurea (Silva Manso) Benth. & Hook. f. The ex S.Moore (yellow ipe), belonging to the Bignoniaceae family, used in the popular for fever, inflammation and healing of skin wounds. The extract was prepared by maceration, using 70% ethanol. Through HPLC analysis, it was possible to identify substances, mainly phenolic, such as lapachol, present in Bignoniaceae. The phenolic content was 21.36 mg / Eag in the antioxidant activity, the effective concentration of 50% was 53.03 ± 1.14 µg / mL. The antimicrobial activity against S.aureus, E. coli and C. albicans was evaluated by microdilution in broth, which verified action against the tested microorganisms. Cell viability has been inhibited for tumor cells, although this has not been observed for normal cells. The LD50 against A.aegypti mosquito larvae was 3504.6 mg / L and there was no mortality in the concentration tested for the snail B.glabrata. Nontoxic or low toxicity for A. salina and T. molitor, respectively, and did not exhibit hemolytic action at concentrations of antibacterial effect. Given the above, it was concluded that the bark extract of the studied species has bioprospecting potential for the future development of antimicrobial products.
ARTICLE | doi:10.20944/preprints202001.0141.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: elderberry minerals; antioxidant activity; phenolic compounds; anthocyanins.
Online: 14 January 2020 (12:08:35 CET)
This study compared the mineral content and bioactive properties of flowers and fruit coming from wild elderberry plants with those of flowers and fruit harvested from elderberry cultivars grown in an orchard. Elderberry fruit and flowers were analysed for the content of selected minerals, phenolic compounds and anthocyanins and for antioxidant activity. Mineral content was determined by atomic absorption spectrometry method, while antioxidant activity and the content of polyphenols and anthocyanins were determined by spectrophotometric methods. Flowers were found to contain more total ash and to have much higher content of most of minerals, except magnesium, which was present in high concentrations in fruit. Fruit showed significantly higher antioxidant activity than flowers, whereas the total phenolic content varied depending on the growing location / cultivar. The material obtained from selected cultivars growing in an orchard had higher antioxidant activity and polyphenol and anthocyanin content than the material obtained from wild plants. Fruit of the ‘Haschberg’ cultivar and flowers of the ‘Sampo’ cultivar had the best bioactive properties of the studied samples.
ARTICLE | doi:10.20944/preprints201910.0300.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: antioxidant activity; phenolic contents; fermentation; wheat; minerals
Online: 27 October 2019 (10:34:26 CET)
High antioxidants level in food is gradually becoming popular because of the enhanced risk of oxidative stress in humans. Bread wheat is rich in vital antioxidants but its major bioactive compounds are not available for the human. This study was conducted with the aim to enhance the phytochemical constituents and antioxidative activity of wheat grains by fermenting it with the use of Bacillus subtilis KCTC 13241. The antioxidative potential was determined by DPPH (2,2-diphenyl-1-picryl- hydrazyl) and ABTS (3-ethyl-benzothiazo- line-6-sulfonic acid) radical scavenging assay as well by the concentration of amino acids, flavonoids, minerals, carbohydrates, and phenolic compounds. Different varieties showed different free radical scavenging potential on fermentation, which was significantly high with respect to their corresponding unfermented wheat varieties. The highest potential was found in a fermented wheat variety named Namhae and this combination can be used in the pharmaceutical and food industries.
ARTICLE | doi:10.20944/preprints201909.0010.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Pinus; needle; Himalayas; phenolics; flavonoids; antimicrobial; antioxidant
Online: 1 September 2019 (10:41:37 CEST)
Environmental interventions and ecological adaptations harbor millions of valued substances and metabolites in plants which can be employed and commercialized for human benefits. Present study encompasses the untapped potential of pine needles of Indo-Himalayan region for the production of different metabolites and their pharmacological significance in terms of antioxidant and antimicrobial activity. Total phenolic and flavonoid content from the needles of ten pine species was quantified using three different solvent systems. Results revealed that out of 10 different selected Pinus species, Pinus taeda showed highest concentration of total phenolics, soluble-F phenolics and flavonoids content (approx.147.02 mg/g, 141.08 mg/g and 21.91mg/g respectively) as compared to other species. On the other hand P. greggii showed highest Bound-W phenolic content (approx.3.62mg/g). Among all the selected plant species, the needles of P.echinata exhibited the highest and P.thunbergii had the lowest ratio of total flavonoids to total phenolics. Most of these compounds were found to have effective antioxidant activities as well as antimicrobial activity, as estimated by oxygen radical absorbance capacity (ORAC) and disk diffusion test respectively.
ARTICLE | doi:10.20944/preprints201812.0169.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: fungicides; dissipation; winemaking process; anthocyanins; antioxidant activity.
Online: 13 December 2018 (14:42:28 CET)
The effect of fungicides on fermentation is of paramount importance to control the quality and safety of wines. In this work, the quality (oenological parameters, color, phenolic content, antioxidant activity, and fungicide residues) of wines from Monastrell grapes fortified with iprovalicarb, mepanipyrim and tetraconazole fungicides was evaluated. Along of the winemaking process, initial residues of mepanipyrim and tetraconazole were removed in more than a 90 % while dissipation of iprovalicarb was around 73 %. Significant statistical differences were found in presence of iprovalicarb and mepanipyrim residues especially at the highest concentration assayed. For both fungicides, an increase of the volatile acidity (between 4 and 8.6 times), the lactic acid content (between 8.6 and 20.5 times), the percentage of polymeric anthocyanins (between 1.3 and 1.7 times) and also a slight increase of the total phenolic index and the total anthocyanins content determined by spectrophotometry was observed. On the contrary, the total monomeric anthocyanins content decreased about 16.3 and 28.6 % in presence of iprovalicarb and mepanipyrim, respectively. These results could be related with the addition of SO2 to the grape must and a higher development of acetic acid or lactic bacteria in presence of these fungicides. The color of the final wines was also different in comparison with the control, with a higher yellow component, color intensity, tonality and hue angle, because of pH changes in the medium. Tetraconazole fermentations had a more similar trend to the control wine, probably due to the lower concentration of this fungicide in the grape must at the initial time. No effects on the antioxidant activity was observed for anyone of the target fungicides. A multivariate statistical analysis was done to view interrelationships between different variables (color and anthocyanins profile). The obtained model allowed to separate wines according to the fungicide treatment applied.
ARTICLE | doi:10.20944/preprints201807.0457.v1
Subject: Chemistry And Materials Science, Electronic, Optical And Magnetic Materials Keywords: bitumen; antioxidant agent; rheology; electron paramagnetic resonance
Online: 24 July 2018 (13:20:22 CEST)
Bitumen aging is the major factor which contributes to the deterioration of the road pavement. Oxidation and volatilization are generally considered as the most important phenomena affecting aging in asphalt paving mixtures. The present study was carried to investigate whether various antioxidants provided by natural resources such as phospholipids, ascorbic acid as well as lignin from rice husk, could be used to reduce age hardening in asphalt binders. A selected bituminous material was modified by adding 2 % w/w of the anti-aging natural additives and subjected to accelerated oxidative aging regimes according to the Rolling Thin Film Oven Test (RTFOT) method. The effects of aging were evaluated based on changes in sol-gel transition temperature of modified bitumens measured through Dynamic Shear Rheology (DSR). Moreover, changes of Electron Paramagnetic Resonance (EPR) spectra were monitored on the bituminous fractions asphaltene and maltene separated by solvent extraction upon oxidative aging. The phospholipids-treated binder exhibited the highest resistance to oxidation and the lowest age-hardening effect compared to the other tested anti-oxidants. The combination of EPR and DSR techniques represents a promising method for elucidating the changes in associated complex properties of bitumen fractions promoted by addition of free radical scavengers borrowed by green resources.
ARTICLE | doi:10.20944/preprints201804.0023.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: diamondback moth; 60Co-γ radiation; antioxidant; testis
Online: 2 April 2018 (11:14:24 CEST)
The diamondback moth, Plutella xylostella (Linnaeus), is one of the notorious pests causing substantial loses to many cruciferous vegetables across the nations. We have got the result that 200Gy dosage irradiated 6-day male pupae of P. xylostella inducing F1 generation sterile. First, in our research, we detected Oxidase system and stress response mechanism of irradiated pupae, the results displayed that 200Gy irradiation significantly alters the antioxidant enzyme regulation in 6-day male pupae of P. xylostella. The level of SOD, CAT were increased significantly in contrast the level of POD and GST were decreased in 12-24h post-treatment. The heat shock proteins (Hsps) gene expression level was significant increasing, maximum > 2 folds up-regulation of genes were observed in peak. But they also had a trend of gradual recovery with development. Second, in order to explore the irradiated sterility further, we detected the testis LDH and ACP activity found that in male adults testis they increased significantly than control during its development. Thus the present research investigation highlights that the 60Co-γ radiation treatments alters the physiological development of diamondback moth. The results showed that 200Gy dosage resulted stress damage to the body and reproductive system of the diamondback moth.
COMMUNICATION | doi:10.20944/preprints201610.0015.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Blackberry juice; Thermoultrasound; Antioxidant Compounds; Fatty Acids
Online: 7 October 2016 (10:12:21 CEST)
Blackberry (Rubus fruticosus spp) is a fruit that has a significant antioxidant activity, due to its content in anthocyanins and antioxidant compounds. Emerging technologies are required as the thermoultrasound technique that ensures microbial reduction and release of compounds with antioxidant properties. The objective of this study was to evaluate changes in the antioxidant content and fatty acid profile of blackberry juice when it is subjected to conservation treatment (pasteurization and thermoultrasound). The blackberry juice and the extracted oil of blackberry juice with n-hexane (control, pasteurized and thermoultrasonicated) were evaluated in antioxidant activity, fatty acid profile and antioxidant content. The thermoultrasound juice had the highest (p < 0.05) amount of total phenols (1011 mg GAE/L), anthocyanins (118 mg Cy-3-GlE/L); antioxidant activity by ABTS (44 mg VCEAC/L) and DPPH (2665 µmol TE/L) compared to the control and pasteurized samples, as well as, as well as, oil extract of obtained of the thermoultrasound juice presented high antioxidant activity (177.54 mg VCEAC/L to ABTS and 1802.60 µmol TE/L to DPPH). The fatty acid composition of the oil extract showed the presence of myristic, linolenic, stearic, oleic, and linoleic acid, the fatty acid profile was similar in the different samples with the exception of stearic acid where this was higher in control sample. The thermoultrasound treatment can be an alternative to pasteurization treatments because keeps and releases antioxidant bioavailable compounds, preserving their fatty acids.
ARTICLE | doi:10.20944/preprints201609.0018.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: polyphenols, flavonoids, seaweeds, antioxidant activity, anticancer activity
Online: 5 September 2016 (14:23:52 CEST)
Seaweeds are considered as one of the largest biomass producers in marine environment that is rich in bioactive metabolites and a source of natural ingredients for functional foods. The potential antioxidant activity and the potential inhibition of Caco2 cell proliferation, of crude extracts of: Chlorophyta (Ulva lactuca, and Codium tomentosum), Phaeophyta (Cystoseira crinita, Cystoseira stricta, and Sargassum vulgare), and Rhodophyta (Gelidium latifolium, Hypnea musciformis, and Jania rubens) collected from western Libyan coast were evaluated in vitro. The antioxidant activity was determined by reducing power and DPPH assays while cell proliferation, morphological changes and the cell cycle arrest were assessed by MTT, inverted light microscope and flow cytometry methods respectively. The polyphenols and flavonoids rich extracts showed remarkable reducing power and antiradical properties. After exposure of Caco2 cells to; various concentrations of extracts (50, 100,150 and 200 µg/mL) especially from brown algae for 72 h, significantly reduced cell proliferation. The antiproliferative effect of algae extracts was correlated with their polyphenol and flavonoid contents. Cell cycle analysis further showed that cells were arrested in G phases along with an increment in sub-diploidal cell population (sub-G) after extract application. These results imply that seaweeds which are rich in bioactive compounds may be in anticancer drug research programs. However, further investigations are essential to reveal the molecular mechanisms of the anticancer activities of these algae.
ARTICLE | doi:10.20944/preprints202311.1052.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: antimicrobial; antioxidant; nanoparticles; phytochemicals; Silybum marianum
Online: 16 November 2023 (07:50:01 CET)
Silybum marianum is a therapeutic plant belonging to the family Asteraceae. It contains silymarin, as its principal component, and has been reported to demonstrate hepatoprotective activity. The study was aimed to investigate the phytochemical constituents, synthesis of nanoparticles, antioxidant activity and antimicrobial effects of the leaf extract. Extracts were synthesized from AgNO3 and characterized via FT-IR, U.V and XRD. The antioxidant activity was determined using DPPH, H2O2 and β-carotene assays. Similarly, all extracts expressed significant DPPH inhibition (IC50) of 5.1, 5.0, 4.7, 2.3, 4.3 and 1.1 (ug/mL), H2O2 of 1.3, 2.2, 4.7, 5.6, 4.0 and 1.0 (ug/mL) from the methanol/water extract, nanoparticles, n-Hexane, ETOAC, n-Butanol and Ascorbic acid (standard) respectively. The extract exerted scavenging activity on β-carotene with a significant IC50 inhibition of 1.5, 0.8, 5.2, 0.8, 2.7, 4.8 at 0 hour and 1.5, 0.8, 5.2, 0.8, 2.7 and 4.8 (ug/mL) after 2 hours water bath incubation at 50°C in the order of the extracts above. Additionally, nanoparticles and plant extracts significantly (p<0.0001) inhibited the growth of bacteria with mean zone of inhibition ranging 7-13 mm and 4-11 mm. This study demonstrated that extracts from different solvents of S. marianum possess significant antioxidant activity, as well as antimicrobial effects which are all concentration dependent. Thus, the result suggests that methanolic/water leaf extract of S. marianum could serve as a potential source of antioxidants and can be explored as a therapeutic agent in free radical induced diseases.
ARTICLE | doi:10.20944/preprints202311.0991.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: purple carrot; elicitor; anthocyanins; storage; antioxidant activity; carotenoids
Online: 15 November 2023 (10:02:49 CET)
Black-purple carrots possess, apart from carotenoids, high content of other bioactive pigments such as anthocyanins. However, both carotenoids and anthocyanins are modified over cold storage due to their lability. In this work, we investigated the effect of the postharvest elicitation on nutritional and organoleptic quality of purple carrots over storage at 5°C for 21 days. Based on our experience, we considered methyl jasmonate and abscisic acid as elicitors. The values obtained were compared with those provided by the fresh-untreated sample on the treatment day (ie, day 0) and after three-week storage (ie, on day 21), which were used as a reference. As a result, carotenoid content increased naturally in untreated samples over storage whereas anthocyanins maintained invariable. Also, physicochemical parameters reflected apparent organoleptic quality loss. However, the postharvest treatment of purple carrot samples with elicitors resulted in similar carotenoid content in elicited samples to fresh carrots on day 0 as well as lower concentration of anthocyanins and antioxidant activity. Besides, elicitation, particularly with abscisic acid, enabled purple carrot deterioration to be slowed down and, therefore, the organoleptic quality to be preserved. This suggests delaying effect of both elicitors on the spoilage rate of purple carrots over the storage time. These findings indicate that the postharvest application of elicitors may be an interesting conservation method, alternative to traditional procedures, to decelerate decomposition and extend shelf-life of purple carrots.
ARTICLE | doi:10.20944/preprints202310.0891.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Stilbenes; resveratrol; ε-viniferin; vitisin B; interactions; antioxidant
Online: 13 October 2023 (11:18:05 CEST)
The control of oxidative stress with natural active substances could limit the development of numerous pathologies. Our objective was to study the antiradical effects of resveratrol (RSV), ε-viniferin (VNF) and vitisin B (VB) alone or in a combination, and those of a stilbene-enriched ex-tract (fraction). In the DPPH, FRAP, and NO scavenging assays, RSV present the highest activity with an IC50 of 83.69, 15.38 and 229 µM, respectively. Binary combinations resulted in additive interaction in the DPPH assay, synergic interaction for RSV+VNF and antagonistic for the others in the FRAP assay, and additive interaction for RSV+VNF or RSV+VB and antagonistic for VNF+VB in the NO scavenging assay. There was no significant difference between the antioxi-dant activity of the fraction and the combination RSV+VNF. In conclusion, RSV presented the highest effects, followed by VNF and VB. Interactions revealed additive or synergistic effects, depending on the combination of stilbenes and the assay.
BRIEF REPORT | doi:10.20944/preprints202309.0013.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Centella asiatica; Antioxidant; Experimental autoimmune encephalomyelitis; Mitochondrial respiration
Online: 1 September 2023 (13:04:45 CEST)
Centella asiatica (Centella) is a traditional botanical medicine that shows promise in treating dementia based on behavioral alterations seen in animal models of aging and cognitive dysfunction. In order to determine if Centella could similarly improve cognitive function and reduce disease burden in multiple sclerosis (MS), we tested its effects in the neuroinflammatory experimental autoimmune encephalomyelitis (EAE) model of MS. In two independent experiments, C57BL/6J mice were treated following induction of EAE with either a standardized water extract of Centella (CAW) or placebo for 2 weeks. At the dosing schedule and concentrations tested, CAW did not improve behavioral performance, EAE motor disability, or degrees of demyelination. However, CAW-treated mice demonstrated increases in nuclear factor (erythroid-derived 2)-like 2 and other antioxidant response element genes, and increases in mitochondrial respiratory activity. Caw also decreased spinal cord inflammation. Our findings indicate that CAW can increase antioxidant gene expression and mitochondrial respiratory activity in mice with EAE, supporting investigation of the clinical effects of CAW in people with MS.
ARTICLE | doi:10.20944/preprints202309.0004.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: propolis; chemical and functional composition; antioxidant activity; Basilicata
Online: 1 September 2023 (13:01:32 CEST)
The study investigated the chemical and functional characterization of propolis collected in southern Italy, in particular in Basilicata, a region rich in ecological and vegetative biodiversity. Sixteen samples of propolis, collected within a radius of 40 km from each other in the Basilicata region, showed significant differences between the chemical and functional parameters investigated: color index (L*, a*, b*; P<0.05), variation in chemical composition and antioxidant activities, by ABTS and FRAP assays. In general, Lucanian propolis had a low content of waxes (P<0.05) and a high content of resin (P<0.05) and balsams (P<0.05). The content of total phenolic compounds and flavonoids were highly variable, as was the biological capacity. In conclusion, Lucanian propolis showed a remarkable variability, highlighting a significant diversification according to the geographical position and the diversity of the flora surrounding the apiary of which the bees use as a source of resin. This study therefore contributes to the enhancement of the quality of propolis, laying the foundations for the production and marketing of propolis not only in the food industry, but also in the pharmaceutical and cosmetic industries.
ARTICLE | doi:10.20944/preprints202308.0214.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: quercetin; antioxidant; apoptotic; anti-inflammatory activity; colon cancer
Online: 3 August 2023 (02:42:07 CEST)
(1) Background: Colon cancer is one of the leading causes of cancer morbidity and mortality globally. It is a multi-step process that involves genetic and epigenetic modifications leading to histological and morphological changes. Several complementary therapeutic options have been analyzed, shedding light on plant-based medication as a potential treatment for colon cancer. Flavonoids such as quercetin are known to have anti-cancer and anti-inflammatory properties. This in vitro study examines quercetin's anti-inflammatory, anti-apoptotic, anti-angiogenesis effects and antioxidant properties in colon cancer cells. (2) Methods: The antioxidant capacity of quercetin-treated cells was investigated using biochemical assays, and angiogenesis and cytokine levels were assessed using enzyme-linked immunosorbent assay (ELISA). The epigenetic modulation and differential expression of aging, apoptotic, and proliferation genes, and Histone deacetylases (HDACs) were also investigated. (3) Results: In this study, the quercetin-treated group significantly reduced the antioxidant enzymes, cytokines, and VEGF levels, altering the expression of epigenetic factors. Quercetin also induced significant senescence in colon cancer cells. Moreover, a considerable increase was observed in the apoptotic and hTERT genes. In contrast, a decrease in p53, proliferation genes, and HDACs was observed, providing a basis for the clinical use of quercetin in cancer treatment. (4) Conclusion: In vitro studies showed that quercetin treatment efficiently induces senescence and apoptosis in colon cancer cells. We also found that quercetin effectively modulated the expression of p53, Wnt1, CTNNB1, and HDACs, indicating that it could be used to treat colon cancer.
ARTICLE | doi:10.20944/preprints202307.1894.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: biocement; honey; antimicrobial properties; antioxidant properties; osteogenic potential
Online: 28 July 2023 (10:27:27 CEST)
New biocements based on a powdered mixture of calcium phosphate/monetite (TTCPM) modified with the honey addition were prepared by mixing the powder and honey liquid components at a non-cytotoxic concentration of honey (up to 10% (w/v)). The setting process of the cements was not affected by the addition of honey, and the set-ting time of ~4 min corresponded to the fast setting calcium phosphate cements (CPC´s). The cement powder mixture was completely transformed into calcium-deficient nanohydroxyapatite after 24 hours of hardening in simulated body fluid, and columnar growth of long needle-like nanohydroxyapatite particles around the original calcium phosphate particles was observed in honey cements. The compressive strength of honey cements was reduced with the content of honey in the cement. The comparable antibacterial activity of cements with honey solutions was found on Escherichia coli, but very low antibacterial activity was found for Staphylococus aureus for all cements. The enhanced antioxidant inhibitory activity of composite extracts was verified. In vitro cytotoxicity testing verified the non-cytotoxic nature of honey cement extracts, and the addition of honey promoted alkaline phosphatase activity, calcium deposit production, and upregulation of osteogenic genes (osteopontin, osteocalcin, and osteonectin) by mesenchymal stem cells, demonstrating a positive synergistic effect of honey and CPC on the bioactivity of cements that could be promising therapeutic candidates for the repair of bone defects.
ARTICLE | doi:10.20944/preprints202306.0691.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Root length; MtTGA1; Antioxidant Enzyme; hormones; salt stress
Online: 9 June 2023 (09:18:28 CEST)
The TGACG motif-binding factor1 (TGA1) transcription factor, a significant protein in the bZIP transcription factor family, exhibits a myriad of functions, contributes to numerous biological events, and holds substantial application potential. In this study, our analysis revealed a diverse range of photoregulatory and hormone regulatory elements within the MtTGA1 promoter region. The expression profile of MtTGA1 indicated its highest expression in the root, with its regulation influenced by SA, ABA, BR, and GA. Under salt stress conditions, transgenic plants demonstrated significantly longer root lengths and heightened activities of antioxidant enzymes such as ascorbic acid catalase (APX), peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) in their roots and leaves compared to control plants. Simultaneously, the levels of endogenous hormones ABA and BR escalated in transgenic plants, with a marked change in the morphology of their leaf cells. Transcriptome analysis identified a total of 193 differentially expressed genes, implicating a wide array of biological processes. Furthermore, we found that MtTGA1 is able to interact with Medicago truncatula SPX domain containing protein 1 (SPX1). In conclusion, the MtTGA1 transcription factor plays a crucial role in enhancing salt tolerance, which provides new insights for improving plant survival under salt stress conditions.
ARTICLE | doi:10.20944/preprints202305.1137.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: antioxidant; anticancer; glucosidase, physic-chemistry characteristics; acute toxicity
Online: 16 May 2023 (09:31:46 CEST)
Alginate extraction is from seaweed, and lignin separation is from by-product corn (stalks and leaves). Alginate/lignin is a synthetic polymer rich in biological activity of great interest. Antioxidant activities of alginate/lignin were evaluated, such as total antioxidant activity, reducing power activity, DPPH free radical scavenging activity, and α – glucosidase inhibition activity. The test of anticancer activity was on four cell lines (Hep G2, fibroblast, MCF-7, and NCI H460). Determination of physical-chemistry characteristics of alginate/lignin was through FTIR, DSC, SEM_EDS, SEM_EDS mapping, XRD, XRF, and 1H-NMR. A study of acute toxicity of alginate/lignin was on Swiss albino mice. The results showed alginate/lignin possessed antioxidant activity such as total antioxidant activity, reducing power activity, especially, α – glucosidase inhibition activity, and no free radical scavenging activity. Alginate/lignin did not be typical in cancer cell lines. Alginate/lignin existed in a thermally stable regular spherical shape in the investigated thermal region. Some specific functional groups of alginate and lignin did not exist in alginate/lignin crystal. Elements such as C, O, Na, and S were popular in the alginate/lignin structure. LD0 and LD100 of alginate/lignin in mice were 3.91 g/kg and 9.77 g/kg, respectively. Alginate/lignin is the potential for application as pharmaceutical materials, functional foods, and supporting diabetes treatment.
ARTICLE | doi:10.20944/preprints202304.0288.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: Layered double hydroxides; grease; antioxidant; oxidative induction time
Online: 13 April 2023 (03:28:21 CEST)
In this paper, MgAl Layered double hydroxides (LDH) were synthesized by co-precipitation method using a colloid mill and characterized by XRD, IR and SEM. The LDHs was repeatedly tested and compared with different bearing lifetime tester in lithium base grease, and it was found that the environmental-friendly LDHs had greater performance than the traditional antioxidant, and it was the development direction of a new generation of environmental-friendly antioxidants in the future. By adding LDHs into large electric shovel greats (GRK-A) in open-pit coal mine, it can be seen by PDSC evaluation that the service lifetime of grease is extended by 20% while the overall performance of grease is not affected. With the increase of LDHs addition, the grease sample gets the greater activation energy, the stronger thermal oxidation and decomposition resistance. Comparing the energy storage modulus and flow transition index at different temperatures, it can be seen that adding the right amount of LDHs needs close attention for the system oxidation resistance and viscoelasticity. For the electric shovel grease system, the best oxidation resistance and rheological properties can be achieved by adding 2% of LDHs. The rheological viscosity-temperature curves show that the grease samples with different ratios of solid LDHs have better low-temperature properties than the mine grease.
REVIEW | doi:10.20944/preprints202301.0515.v2
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: antioxidant supplements; ROS; oxidative stress analysis; metabolic diseases
Online: 30 January 2023 (02:46:04 CET)
Cells produce reactive oxygen species (ROS) as by-products of metabolism, which can give rise to a two-sided effect on the body under balanced and imbalanced oxidant homeostasis conditions. Antioxidant supplements exert their beneficial efficacy in the treatment of metabolic diseases only when the oxidant homeostasis is imbalanced with the over-production of ROS. Over-supplementation of antioxidant(s) can also cause an imbalanced oxidant homeostasis to exert detriments to the induction of metabolic diseases. This commentary raises a concern that prior to precise supplementation of antioxidants, an establishment of oxidant homeostasis status is required in avoiding an imbalanced oxidant homeostasis in vivo. In searching for valid oxidant stress makers, 3-Nitrotyrosine seems to fit in with the selection criteria and its quantification can be correlated with the degree of oxidative stress in vivo.
REVIEW | doi:10.20944/preprints202301.0470.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: Antioxidant; free radical stress; endothelial dysfunction; dyslipidemia; diet
Online: 26 January 2023 (08:20:52 CET)
There is evidence that behavioral risk factors such as western type diet, and life style can predispose to oxidative stress, deficiency in antioxidant status, hyperglycemia, dyslipidemia and increase in inflammation in tissues of various organs: beta cells of the pancreas, LDL receptors in the hepatocytes, endothelium, neurons, osteocytes and gut. Further studies indicate that diets rich in antioxidant flavonoids, omega-3 fatty acids and fiber in foods were inversely associated whereas western-type foods were positively associated with risk of mortality due to cardiovascular diseases (CVDs). One important cause for beneficial effects of diet may be certain foods and nutrients such as vegetables, fruits and whole grains that are rich in fiber and flavonoids, known to produce liters og molecular hydrogen in the gut. It seems that, high-fiber diets, prebiotic and probiotics can produce greater hydrogen, which acts as an antioxidant and may inhibit free radical generation. Recent studies indicate that molecular hydrogen can inhibit hydroxyl and nitrosyl radicals and can directly act as antioxidant in the cells and tissues, which can cause marked decline in oxidative stress and inflammation leading to significant decline in CVDs and metabolic diseases. Clinical and experimental studies indicate that hydrogen therapy such as hydrogen rich water can provide benefits in the management of CVDs and metabolic diseases. Larger studies are necessary to verify the role of hydrogen administration in CVDs.
ARTICLE | doi:10.20944/preprints202207.0258.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Melatonin; glial scar; insertion trauma; anti-inflammatory; antioxidant
Online: 18 July 2022 (10:08:28 CEST)
Neural electrode insertion trauma impedes the recording and stimulation capabilities of numerous diagnostic and treatment avenues. Implantation leads to the activation of inflammatory markers and cell types, which is detrimental to neural tissue health and recording capabilities. Oxidative stress and inflammation at the implant site have been shown to decrease with chronic administration of antioxidant melatonin at week 16, but its effects on the acute landscape have not been studied. To assess the effect of melatonin administration in the acute phase, specifically the first week post-implantation, we utilized histological and q-PCR methods to quantify cellular and molecular indicators of inflammation and oxidative stress as well as two-photon microscopy to track the microglial responses in real-time. Histological results indicate that melatonin effectively maintained neuron density surrounding the electrode, inhibited accumulation and activation of microglia, astrocytes, and reduced oxidative tissue damage. The expression of the pro-inflammatory cytokines, TNF-α and IL-6, were significantly reduced in melatonin-treated animals. Additionally, microglia encapsulation of the implant surface was inhibited by melatonin as compared to control animals following implantation. Our results combined with previous research suggest that melatonin is a particularly suitable drug for modulating inflammatory activity around neural electrode implants both acutely and chronically, translating to more stable and reliable interfaces.
REVIEW | doi:10.20944/preprints202207.0040.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Kalanchoe; antibacterial; anti-inflammatory properties; wound healing; antioxidant
Online: 4 July 2022 (08:27:24 CEST)
The Kalanchoe genus is composed of more than 100 species that usually thrive in tropical environments, which have been used in folkloric medicine to treat various illnesses, including dermatological conditions. With this, the present study assesses the pharmacognostical and pharmacological properties of different species of the Kalanchoe genus as elements for a potential treatment for dermatological-related conditions, from findings of existing literature and studies. It was analyzed that the Kalanchoe pinnata plant, or one of the most common species of Kalanchoe, have been observed to have distinct morphological and microscopic characteristics. Further, it was discovered that different species of Kalanchoe have anti-inflammatory, antioxidant, antibacterial, and wound healing properties, which enable the plant to be used for dermatological products that are available to the market. With this, it is recommended that further studies be conducted in other understudied species of Kalanchoe regarding their pharmacological properties, as well as the use of other structures of the Kalanchoe plant for treatment of various dermatological conditions.
REVIEW | doi:10.20944/preprints202204.0093.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Electrophile signaling; drug mechanism; immunology; antioxidant response; apoptosis
Online: 11 April 2022 (10:39:31 CEST)
Here we draw insights from the latest serendipitous findings made on the opposing roles of a validated drug-target protein Keap1. We weigh up how natural reactive electrophiles and electrophilic small-molecule drugs in clinical use directly impinge on seemingly conflicting, yet both Keap1-electrophile-modification-dependent, cell-survival- vs. cell-death-promoting behaviors. In the process, we convey how understanding reactive chemical-signal regulation at a single-protein-specific level is an enabling necessity in deconstructing otherwise intricate reactive-small-molecule-responsive cellular pathways. We hope this opinion piece further spurs the broader interests of basic and pharmaceutical research communities toward better understanding of molecular mechanisms underpinning reactive small-molecule-regulated signaling subsystems.
ARTICLE | doi:10.20944/preprints202108.0059.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Ballota nigra; salinity; antioxidant; enzyme activity; phytochemical composition
Online: 2 August 2021 (16:31:13 CEST)
Black horehound (Ballota nigra L.) is one of the important medicinal plants, which is a rich source of health-promoting essential oils. Salinity stress affects plant development and alters the quality and quantity of plants extracts and their composition. This study was aimed to investigate the effect of salinity on morphological, physiological characteristics, and secondary metabolites of B. nigra under greenhouse, and in vitro culture conditions. The plants were treated with different concentrations of NaCl (25, 50, 75, 100 mM) and fresh and dry weight of leaf and stem were measured as well as morphological characteristics of the plant. Plant growth was reduced with the increased salinity concentrations. The results showed that all growth-related traits and SPAD were decreased both in vivo and in vitro. Additionally, increased salt concentration affected the cell membrane integrity. Total phenolics content of plants growing in the greenhouse, increased by 21% at 50 mM NaCl, but at higher stress levels (100 mM NaCl), the amounts were decreased significantly. Total flavonoids contents followed similar patterns, with a slight difference. In addition, the maximum and minimum total phenolics contents of plants growing under in vitro condition were observed at 50 mM NaCl and control treatments, respectively. Increasing the salt concentration significantly affected the total flavonoids content, and as a result, the highest amount was observed in 50 and 75 mM NaCl treatments. Antioxidant activity was also measured. Among the NaCl treatments, the highest DPPH scavenging activities (IC50) under greenhouse and in vitro conditions were detected at 50 mM and 25 mM concentrations, respectively. In general, based on the results, with increasing the salinity level to 75 mM, the activities of CAT and APX were significantly upregulated in both greenhouse and in vitro culture conditions. A correlation between total phenolics and flavonoids contents as well as antioxidant activity were obtained. With shifting salinity stress, the type and the amount of the identified essential oil compounds changed. Compounds such as styrene, tridecanol, germacrene-D, beta-Ionone, beta-bisabolene, and caryophyllene oxide increased compared to the controlled treatment.
ARTICLE | doi:10.20944/preprints202103.0735.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: antioxidant enzymes; pharmaceutical residues; pesticides; detergents; integrative indexes
Online: 30 March 2021 (12:26:28 CEST)
Worldwide anthropogenic activities result in the production and release of poten-tially damaging toxic pollutants into ecosystems, thereby jeopardizing their health and continuity. Research studies and biomonitoring programs attend to this emerging problematic by applying and developing statistically relevant indexes that integrate complex biomarker response data to provide an holistic approach reflecting toxically induced alterations at the organism’s or population level. Ultimately, indexes allow simple result communication, enhancing policy makers understanding, so contributing for better resource and environmental managing policies. In this study three indexes , the Integrated Biomarker Response index (IBR), the Bioeffects Assessment Index (BAI) and the Principal Components Analysis (PCA), were evaluated for their sensitivity in revealing toxically induced stress patterns in cells of the diatom Phaeodactylum tricornutum under contaminant exposure. The set of biomarkers selected for index construction comprise the anti-oxidant enzymes APX, CAT and SOD, and the lipid peroxidation marker TBARS. Several significant inverse correlations with the concentration gradients applied, , was noticed for all indexes, though, the IBR excels for its reliability in delivering statistically significant dose-response patterns for four out of the five compounds tested.
ARTICLE | doi:10.20944/preprints202101.0204.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Antioxidant; Anti-inflammatory; Chitosan; Flavonoids; Phenolics; Silybum marianum
Online: 11 January 2021 (15:59:31 CET)
Silybum marianum (L.) Gaertn is a rich source of antioxidants and anti-inflammatory flavonolignans with great potential for use in pharmaceutical and cosmetic products. Its biotechnological production using in vitro culture system has been proposed. Chitosan is a well-known elicitor that strongly affects both secondary metabolites and biomass production by plants. The effect of chitosan on S. marianum cell suspension is not known yet. In the present study, suspension cultures of S marianum were exploited for their in vitro potency to produce bioactive flavonolignans in the presence of chitosan. Established cell suspension culture was maintained on the same hormonal media supplemented with 0.5 mg/L BAP (6-benzylaminopurine) and 1.0 mg/L NAA (α-naphthalene acetic acid) under photoperiod 16/8 h (light/dark) and exposed to various treatments of chitosan (ranging from 0.5 to 50.0 mg/L). The highest biomass production was observed for cell suspension treated with 5.0 mg/L chitosan, resulting in 123.3 g/L fresh weight (FW) and 17.7 g/L dry weight (DW) productions. Chitosan treatment resulted in an overall increase in the accumulation of flavonoids, phenolic compounds and silymarin. High accumulation levels of silybin B, silydianin and silybin A were recorded by HPLC analysis. The corresponding extracts displayed interesting antioxidant and anti-inflammatory capacities. In particular, high ABTS antioxidant activity (741.5 μM Trolox C equivalent antioxidant capacity) was recorded in extracts obtained in presence of 0.5 mg/L of chitosan. On the opposite, highest inhibitions of cyclooxygenase 2 (COX-2, 30.5 %), secretory phospholipase A2 (sPLA2, 33.9 %) and 15-lipoxygenase (15-LOX-2, 31.6 %) enzymes involved in inflammation process were measured in extracts obtained in presence of 5.0 mg/L of chitosan. Taken together, these results highlight the high potential of the chitosan elicitation of the S. marianum cell suspension for enhanced production of antioxidant and anti-inflammatory silymarin-rich extracts.
ARTICLE | doi:10.20944/preprints202011.0442.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: auditory; deafness; acoustic trauma; hair cells; antioxidant; otoprotection
Online: 17 November 2020 (09:40:53 CET)
Noise induces oxidative stress in the cochlea followed by sensory cell death and hearing loss. The proof of principle that injections of antioxidant vitamins and Mg2+ prevent noise-induced hearing loss (NIHL) has been established. However, effectiveness of oral administration remains controversial and otoprotection mechanisms unclear. Using auditory evoked potentials, quantitative PCR and immunocytochemistry, we explored effects of oral administration of vitamins A, C, E and Mg2+ (ACEMg) on auditory function and sensory cell survival following NIHL in rats. Oral ACEMg reduced auditory thresholds shifts after NIHL. Improved auditory function correlated with increased survival of sensory outer hair cells. In parallel, oral ACEMg modulated the expression timeline of antioxidant enzymes in the cochlea after NIHL. There was increased expression of Glutathione peroxidase-1 and Catalase at 1 and 10 days, respectively. Also, pro-apoptotic Caspase-3 and Bax levels were diminished in ACEMg-treated rats, at 10 and 30 days, respectively, following noise overstimulation, whereas, at day 10 after noise exposure, the levels of anti-apoptotic Bcl-2, were significantly increased. Therefore, oral ACEMg improves auditory function by limiting sensory hair cell death in the auditory receptor following NIHL. Regulation of the expression of antioxidant enzymes and apoptosis-related proteins in cochlear structures is involved in such otoprotective mechanism.
ARTICLE | doi:10.20944/preprints202009.0231.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: organic acids; sugars; anthocyanins; antioxidant enzymes; ascorbic acid
Online: 10 September 2020 (09:11:16 CEST)
The changes in nutritional quality, bioactive compounds and antioxidant enzymes in the juice of four blood orange cultivars (‘Moro’, ‘Tarocco’, ‘Sanguinello’ and ‘Sanguine’) stored during 6 months at 2 and 5 °C plus 2 days at 20 °C for shelf life were studied. Sucrose was the sugar found at higher concentration and decreased during storage for all cultivars, as did glucose and fructose. Organic acids decreased at both temperatures and the highest content was found in ‘Sanguinello’, especially the major (citric acid) and ascorbic acid. Total phenolics content (TPC), total anthocyanins (TAC), and the individual (cyanidin 3-glucoside and cyanidin 3-(6″-malonylglucoside)) increased for all cultivars, the ‘Sanguinello’ having the higher concentrations. Antioxidant enzymes catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD) were higher also in ‘Sanguinello’ and increased during storage. Overall, these results together with the sensory analysis suggest that ‘Sanguinello’ would be the best cultivar for prolonged storage.
ARTICLE | doi:10.20944/preprints202005.0254.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: Antioxidant activity; Arabica coffee; Caffeine reduction; Steaming times
Online: 15 May 2020 (10:22:59 CEST)
In addition to being a source of freshener, coffee has an enormous possibility to be developed as a source of antioxidants for functional beverages. However, efforts to increase the value added of coffee as a health functional drink are still hindered by the presence of high level of caffeine, which is thought to have adverse effects on health, especially for coffee lovers who are vulnerable to caffeine. This study aims to optimise the steaming duration to produce low caffeine coffee while maintaining the sensory attributes and antioxidant compounds contained in it. Indonesian Arabica (Leksana variety) green coffee beans were steamed with multi-level steaming durations (0, 20, 40, 60 and 80 min) followed by roasting (medium-dark roast degree), grinding, and brewing (espresso method). The results indicate that caffeine content in the coffee was inversely proportional to the steaming duration. The lowest caffeine content was obtained from the treatment of 80 min steaming with a decrease of caffeine level up to 28.73%. However, the longer process of steaming caused a significant decrease in polyphenol content and antioxidant activity. The hedonic test shows that the steaming treatment of coffee can increase preferences of panellists. There were two driving attributes that influence the overall liking of coffee, namely: bitterness and aftertaste. Coffee obtained from the treatment of 60 min steaming was most preferred by panellists. The results of APLSR biplot mapping show that there was a big change in almost all attributes in the coffee samples after 40 min steaming.
ARTICLE | doi:10.20944/preprints202001.0217.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: antioxidant; Nigella sativa; secondary metabolites; thymoquinone; DNA damage
Online: 19 January 2020 (14:33:58 CET)
Nigella sativa (NS) is an effective medicinal plant possessing noteworthy antioxidant property. In NS, there are more than hundred phyto-chemicals reported, out of which thymoquinone is the utmost active phyto-constituent having sturdy antioxidative property. Thymoquinone is a cyclicdione, when reacts with sodium azide, converts into α-azido ketones i.e its analogs which are handy with extensive range of reactions. Sodium azide induces stress in plants thereby, modulating the antioxidant system. The present investigation was planned to elucidate the effect of sodium azide at different concentrations (5µM, 10µM, 20µM, 50µM, 100µM and 200µM) on its secondary metabolites (mainly thymoquinone) in NS callus culture extract (NSE). The results showed sodium azide effect on thymoquinone content and a concentration dependent boost in antioxidant property. It was also observed that thymoquinone content and percent yield (analyzed by RP-HPLC; Reverse Phase- High Performance Liquid Chromatography) were minimum (0.033±0.006% and 0.420±0.045%, respectively) at 200 µM sodium azide used. Whereas, antioxidant activity (analyzed by DPPH; 2, 2-diphenyl-1-picrylhydrazyl) was found to be maximum (3.873±0.402%) at same dose. Further, analysis was done for inhibition of oxidative DNA damage at different concentrations of sodium azide on NSE, maximum inhibition of DNA damage (0.243±0.017%) was found at 200 µM concentration of sodium azide. When correlated, strong positive correlation was observed between percent yield and percent thymoquinone, antioxidant property and inhibition of DNA damage. Whereas, strong negative correlation was observed between percent yield and antioxidant property, percent thymoquinone and antioxidant property, percent thymoquinone and inhibition of DNA damage. The findings evidently point out that the content of thymoquinone, antioxidant property and inhibition of DNA damage was affected by sodium azide.
ARTICLE | doi:10.20944/preprints201911.0137.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Hibiscus sabdariffa; phenolic compounds; spray-drying; antioxidant capacity
Online: 13 November 2019 (03:15:28 CET)
Aqueous and ethanolic extracts of Hibiscus sabdariffa were spray-drying using maltodextrin (MD) and gum arabic (GA) as carriers agents. An experimental design Taguchi L8 with seven variables was implemented. Physicochemical properties in the encapsulates were evaluated by UV-Vis, XRD, spectroscopy and gravimetric techniques. Treatments with aqueous extracts showed the highest concentration of total soluble polyphenols (TSP) 32.12- 21.23 mg EAG/g DW, and antioxidant capacity (AOX) for ABTS assay. The best treatment for TSP and AOX was T4: 2.5% Hibiscus w/w, aqueous extracts, decoction, extract-to-carrier ratio 1:1 (w/w), proportion to carriers (MD:GA) 80:20 (w/w), 10000 rpm, 150°C. Taguchi L8 model is a tool that allows the use of multiple variables with a low number of treatments that indicate the drying conditions that give the best parameters, focusing mainly on TSP and AOX, in addition, is a good alternative for the preservation and stability of the PC in Hibiscus.
Subject: Biology And Life Sciences, Toxicology Keywords: chromerids; transcriptome; heavy metal; antioxidant enzymes; xenobiotics; phylogenies
Online: 21 September 2019 (09:46:22 CEST)
Heavy metal pollution is an increasing global concern. Among heavy metals, mercury (Hg) is especially dangerous because of its massive release into the environment and high toxicity, especially for aquatic organisms. The molecular response mechanisms of algae to Hg exposure are mostly unknown. Here, we combine physiological, biochemical, and transcriptomic analysis to provide, for the first time, a comprehensive view on the pathways activated in Chromera velia in response to toxic levels of Hg. Production of hydrogen peroxide and superoxide anion, two reactive oxygen species (ROS), showed opposite patterns in response to Hg2+ while reactive nitrogen species (RNS) levels did not change. A deep RNA sequencing analysis generated a total of 307,738,790 high-quality reads assembled in 122,874 transcripts, representing 89,853 unigenes successfully annotated in databases. Detailed analysis of the differently expressed genes corroborate the biochemical results observed in ROS production and suggests novel putative molecular mechanisms in the algal response to Hg2+. Moreover, we indicated that important transcription factor (TF) families associated with stress responses differentially expressed in C. velia cultures under Hg stress. Our study presents the first in-depth transcriptomic analysis of C. velia, focusing on the expression of genes involved in different detoxification defense systems in response to heavy metal stress.
ARTICLE | doi:10.20944/preprints201907.0145.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Antinociception, antioxidant, Azadiracta Indica, DPPH assay, Opioids system
Online: 10 July 2019 (10:23:01 CEST)
Background: Azadirachta indica (Neem) is a communal plant of Meliaceae family called Neem Or Kadunimb in Maharashtra, India Neem stated anti-inflammatory through regulation of proinflammatory enzyme activities with COX and LOX enzyme. Previous studies show that Azadirachta Indica (neem) and its chief constituents play an essential role in anticancer management via the modulation of different molecular pathways including NF-κB, p53, PI3K/Akt, Bcl-2, pTEN, and VEGF. Many parts of the plant are traditionally used in the treatment of various pharmacological action, the analgesic activity of Neem Seed Oil has already reported but Neem Leaves. Methods: The antinociceptive activity of Azadirachta Indica Leaves (AZIL) was examined using heat-induced-mechanical (hot-plate and tail-immersion test) and chemical-induced (acetic acid, formalin, glutamic acid, cinnamaldehyde) nociception models in mice at 50,100, and 200 mg/kg doses. ATP-sensitive K+ channel pathway, cyclic guanosine monophosphate (cGMP) pathway and involvement of the opioid system were also tested using glibenclamide, methylene blue, and naloxone/morphine respectively. The methanolic extract of leaves of A.Indica was assessed by using different in vitro antioxidant models of screening like scavenging of 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical, nitric oxide radical, superoxide anion radical, and hydroxyl radical. Results: AZIL showed antinociceptive activity and antioxidant activity. In both hot plate and tail immersion tests AZIL significantly increases the latency to the thermal stimuli. In the acetic acid-induced writhing test the extract repressed the number of abdominal writhing. Similarly, AZIL produced substantial dose-dependent inhibition of paw licking in both neurogenic and inflammatory pain induced by intraplantar injection of formalin. As well, AZIL also expressively withdrawn cinnamaldehyde-induced pain and the glutamate-induced pain in mice. It was also proved that pretreatment with naloxone significantly reversed the antinociception produced by AZIL in mechanical tests signifying the involvement of the opioid system in its effect. Furthermore, administration of methylene blue, enhanced AZIL induced antinociception while glibenclamide, an ATP-sensitive K+ channel antagonist, could not converse antinociceptive activity induced by AZIL. Conclusion: Based on the results of the present study it can be said that AZIL keeps significant antinociceptive activity which acts in both central and peripheral mechanisms.
ARTICLE | doi:10.20944/preprints201812.0050.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Semen Allii Fistulosi; protein; extraction; characterization; antioxidant activity
Online: 4 December 2018 (09:32:34 CET)
Semen Allii Fistulosi is the seed of Allium fistulosum L. of the Liliaceae family. The purpose of this study was to extract, characterize, and evaluate the antioxidant activity in vitro of proteins from Semen Allii Fistulosi (PSAF). Using single factor and orthogonal design, the optimum conditions of extraction were determined to be as follows: extraction time 150 min, pH 8.5, temperature 60℃, and ratio (v/w, mL/g) of extraction solvent to raw material 35. The isoelectric point of the pH was determined to be about 4.4 and 10.2, by measuring the protein content of PSAF solutions at different pH. The amino acid composition of PSAF was determined by high performance liquid chromatography (HPLC), and the results suggested that the species of amino acids contained in the PSAF was complete. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS–PAGE) analysis showed the molecular weight was mainly between 40 and 55 kDa, and Fourier-transform infrared spectroscopy (FTIR) characterized prevalent protein absorption peaks. PSAF exhibited potent scavenging activities against DPPH assays, via targeting of hydroxyl and superoxide radicals, while chelating Fe2+ activity, and demonstrating weak reducing power. This work revealed that PSAF possessed potential antioxidant activity in vitro, suggesting potential for use of PSAF as a natural antioxidant.
ARTICLE | doi:10.20944/preprints201811.0283.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Arthrospira maxima; antioxidant; cardiovascular; nutraceutical; systolic blood pressure
Online: 12 November 2018 (10:42:25 CET)
1) Background: Spirulina (Arthrospira) maxima has shown beneficial effects such anti-dyslipidemic, antiviral, antioxidant and antihypertensive. However, there are few and limited clinical studies. 2) Methods: a prospective, randomized, parallel pilot study of 4.5 g administration of Spirulina maxima or placebo for 12 weeks in 16 patients with systemic arterial hypertension undergoing treatment with ACE inhibitors was performed to assess the effects on endothelial damage and oxidative stress indicators. The blood levels of sICAM-1, sVCAM-1, endothelin-1, and sE-selectin were quantified; the activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase and concentrations of reduced glutathione, oxidized glutathione, and thiobarbituric acid reactive susbtances, were also quantified before and after the treatment period. 3) Results: There were statistically significant (p < 0.05) decreases in systolic blood pressure, sVCAM-1, sE-selectin and endothelin-1 levels, and increases in glutathione peroxidase activity and oxidized glutathione levels. 4) Conclusion: The effects found in the present study agree with antihypertensive and antioxidant effects previously reported for Spirulina maxima. However, this is the first report about the effects on indicators of endothelial damage. More research in this field is necessary to gain an insight into the effects of Spirulina on these indicators.
ARTICLE | doi:10.20944/preprints201810.0425.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Tea; Salvia officinalis; Rosmarinus officinalis; Total phenolic; Antioxidant
Online: 18 October 2018 (12:52:37 CEST)
Vitamin B2, also known as riboflavin (RF) is an essential micronutrient for human health and must be obtained from dietary sources. Plants biosynthesize riboflavin and are important dietary sources of vitamin B2 for humans. Our present study reports sensitive detection of Vitamin B2 in widely consumed for tea infusions, namely black, green, sage and rosemary tea infusions, by a capillary electrophoresis method combined with laser induced fluorescence detection. Moreover, the correlation between Vitamin B2 contents of tea plants with their total phenolics (TPs) and antioxidant capacity are evaluated in this study. Whereas green teas have the highest TPs and antioxidant capacity, the highest RF contents are in sage infusions. The RF contents range between 0.34 and 10.36 µg/g for all tea samples studied. Comparing RF contents of tea samples found in this study to the RF contents of known RF sources, tea infusions are proposed as important dietary sources of Vitamin B2.
REVIEW | doi:10.20944/preprints201809.0422.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: LDL-oxidation; DNA-damage; antioxidant vitamins; oxidative stress
Online: 20 September 2018 (16:53:42 CEST)
Radical oxygen species formed in human tissue cells by many endogenous and exogenous pathways, cause extensive oxidative damage, which has been linked to various human diseases. This review paper provides an overview of lipid peroxidation and focuses on the free-radicals initiated processes of LDL oxidative modification and DNA oxidative damage, which are widely associated to the initiation and development of atherosclerosis and carcinogenesis, respectively. The article subsequently provides an overview of the recent human trials or even in vitro investigations on the potential of natural antioxidant compounds (such as carotenoids, vitamins C and E) to monitor LDL and DNA oxidative changes.
ARTICLE | doi:10.20944/preprints201806.0204.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Aspergillus flavus; antioxidant gallic acid; aflatoxin; farB; creA
Online: 13 June 2018 (09:59:49 CEST)
Aflatoxin biosynthesis is correlated with oxidative stress and is proposed to function as a secondary defense mechanism to redundant intracellular reactive oxygen species (ROS). We find that the antioxidant gallic acid inhibits aflatoxin formation and growth in A. flavus in a dose-dependent manner. Global expression analysis (RNA-Seq) of gallic acid treated A. flavus showed that 0.8% (w/v) gallic acid revealed two possible routes of aflatoxin inhibition. Gallic acid significantly inhibited the expression of farB, encoding a transcription factor that participates in peroxisomal fatty acid β oxidation, a fundamental contributor to aflatoxin production. Secondly, the carbon repression regulator encoding gene creA was significantly down regulated by gallic acid treatment. CreA is necessary for aflatoxin synthesis and aflatoxin biosynthesis genes were significantly downregulated in DcreA mutants. In addition, the results of antioxidant enzyme activities and the lipid oxidation levels coupled with RNA-Seq data of antioxidant genes indicated that gallic acid may reduce oxidative stress through the glutathione- and thioredoxin-dependent systems in A. flavus.
ARTICLE | doi:10.20944/preprints201703.0194.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: aromatic plants; HPLC; antioxidant capacity; DPPH; Rancimat test
Online: 27 March 2017 (09:57:43 CEST)
The antioxidant properties and polyphenol content of some selected aromatic plants grown in Greece were studied. Plants were refluxed with 60% methanol after acid hydrolysis. The phenolic substances were quantified by HPLC-DAD. The antioxidant capacity of the extracts was determined with the Rancimat test using sunflower oil as substrate. Free radical scavenging activity was measured using the stable free radical 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Results were compared with standard BHT and ascorbic acid. Total phenol concentration of the extracts was estimated with Folin-Ciocalteu reagent using gallic acid as standard.
ARTICLE | doi:10.20944/preprints202311.0084.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: thyme; essetial oil; chemical type; antioxidant; multivariate statistical analysis
Online: 2 November 2023 (07:20:51 CET)
Thymus is an herbaceous perennials or subshrubs of the Lamiaceae family and is widely distributed worldwide. Essential oils extracted from thymus have attracted much attention owing to their potential biological functions. Here, we evaluated the chemical compositions of eight thyme essential oils (TEOs) using gas chromatography-mass spectrometry and assessed their antioxidant activity and in potential role in antibacterial and tumor therapy. The results showed that (1) the main components in eight TEOs were monoterpene hydrocarbons and oxygenated monoterpenes, and the chemical compositions of TEOs were affected by the specie factor; (2) eight TEOs could be divided into 3 groups (thymol-, geraniol-and nerol acetate-type), and thymol was main type; (3) eight TEOs had some common compounds, such as thymol and p-cymene, which were the main components in seven TEOs; (4) eight TEOs had antioxidant activit, and thymol-type EOs had strong antioxidant activity, while geraniol-type EOs had relatively weak antioxidant activity. In addition, it was found thymol had strong antibacterial activity against the growth of Escherichia coli and Staphylococcus aureus, and antimigratory activity of A549 cell. Overall, our results can provide theoretical basis for further exploring the function of natural products from thyme essential oils.
REVIEW | doi:10.20944/preprints202310.1953.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Hydrogen; gas medicine; antioxidant; mitochondria; Keap1-Nrf2; Nrf2 activator
Online: 31 October 2023 (03:00:32 CET)
The gas molecules O2, NO, H2S, CO, CH4 , have been increasingly used for medical purposes. Beside these gas molecules, H2, the smallest diatomic molecule in nature, has become a rising star in gas medicine in the past few decades. As a non-toxic and easily accessible gas, H2 has shown preventive and therapeutic effects on various diseases of the respiratory, cardiovascular, central nervous and other systems, but the mechanisms are still unclear and even controversial, especially the mechanism of H2 as a selective radical scavenger. Mitochondria are the main organelles regulating energy metabolism in living organisms, as well as the main organelle of reactive oxygen species generation and target. We propose that the protective role of H2 may be mainly dependent on its unique penetrating ability to everywhere of the cells to regulate mitochondrial homeostasis by activating the Keap1-Nrf2 phase II antioxidant system, rather than its direct free radical scavenging activity. In this review, we summarize the protective effects and focus on the mechanism of H2 as a mitochondria-targeting nutrient by activating the Keap1-Nrf2 system in different disease models, and wish to provide a more rational theoretical support for the medical applications of hydrogen.
ARTICLE | doi:10.20944/preprints202310.1403.v1
Subject: Public Health And Healthcare, Other Keywords: Chestnut biodiversity; pericarp; water extraction; antioxidant activity; cancer cells
Online: 23 October 2023 (09:56:13 CEST)
The residue of chestnut processing generates a large amount of waste material, a resource not adequately exploited. The phenolic composition of water extracts from discarded pericarp of four (MURG, LOCG, ILDP and COEV) chestnut accessions and one marron variety belonging to the Sardinian biodiversity was studied. The antioxidant capacity of cold and hot water extracts was determined by DPPH, ABTS and cyclic voltammetry tests. The antiproliferative effect on normal cells (fibroblasts), and colon (RKO and SW48), breast (MCF7) and melanoma (B16F10) cancer cells, was evaluated by biological assays. MTT test demonstrated that temperature and different extraction times significantly influenced the growth of cells, both normal and tumor. The fibroblast viability was significantly reduced by moderate doses of cold extracts, but only by doses greater than 250 µg/ml of hot extracts, regardless of the accession or cultivar. An even more marked effect was observed when RKO and SW48 were treated with cold extracts, while treatments on B16F10 melanoma cells resulted less effective. Differently, the cold extracts of all accessions induced a significant increase in MCF7 cell viability starting from moderate doses (50 µg/ml), whereas hot extracts had a similar, but less evident, effect compared to reference fibroblasts.
REVIEW | doi:10.20944/preprints202309.1502.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: kratom; neurological effects; mitragynine; 7-hydroxymitragynine; antioxidant and antiinflammation
Online: 22 September 2023 (04:31:30 CEST)
Kratom (Mitragyna speciosa Korth. Havil) has been considered a narcotic drug for years, barred by the law in many parts of the world, while extensive research over the past few decades proves its several beneficial effects some of which are still in ambiguity. In many countries, including Thailand, the indiscriminate use and abuse of Kratom have led to the loss of life. Nonetheless, researchers have isolated almost fifty pure compounds from Krat-om, most of which are alkaloids. The most prevalent compounds, mitragynine and 7-hydroxy mitragynine, are reported to display agonist morphine-like effects on human μ-opioid receptors and antagonists at κ- and δ-opioid receptors with multimodal effects at oth-er central receptors. Mitragynine is also credited to be one of the modulatory molecules for the Keap1-Nrf2 pathway and SOD, CAT, GST, and associated gene’s upregulatory cascades leading to play a pivotal role in neuroprotective actions while its long-high dose is evident to cause the neuronal disorder. Additionally, the anti-inflammatory, antioxidative, antibac-terial, and gastroprotective effects are well-cited. In this context, this review focuses on the research gap to resolve the ambiguities about the neuronal effects of kratom to demonstrate its prospects as a therapeutic target for neurodisorders connecting with other pharmacologi-cal effects.
ARTICLE | doi:10.20944/preprints202308.0396.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: salt stress; photosynthesis; antioxidant enzymes; ROS scavenging; Meyerozyma guilliermondii
Online: 4 August 2023 (12:38:03 CEST)
How to improve plant tolerance and yield under salt stress is critical for ensuring sufficient food supply since plant survival and agricultural productivity are both affected by salinity. Some evidence has showed that beneficial microorganisms have a high ability to improve plant salt tolerance and increase crop yield. But few studies were involved in effects of halotolerant yeasts on plants under salt stress. In this present research, Meyerozyma guilliermondii, a halotolerant yeast, was inoculated with tomato plants followed by salt treatment of four different NaCl concentrations (0, 100, 200, and 300 mM). Our results showed that inoculation of M. guilliermondii increased the chlorophyll biosynthesis and photosynthetic machinery effectiveness under salt stress, contributing to biomass accumulation. Under salt treatment of 300 mM NaCl, the yeast inoculation significantly increased ascorbate concentrations in leaves, yet showed no effects on levels of glutathione and proline. Antioxidant enzymes were affected differently by the yeast inoculation. It was found that the yeast inoculation increased superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities under 300, 100, and 200 mM NaCl, respectively. Total soluble sugar levels increased in inoculated tomato plant leaves; however, there were no significant differences between different NaCl concentrations. Under 300 mM NaCl, the yeast inoculation significantly decreased H2O2 levels and reduced malondialdehyde levels. All together, our results showed that halotolerant yeast M. guilliermondii inoculation might be a strong candidate for regulating tomato growth under salt stress by increasing ability to scavenge reactive oxygen species and chlorophyll intactness, and by strengthening photosynthetic machinery.
ARTICLE | doi:10.20944/preprints202308.0206.v1
Subject: Medicine And Pharmacology, Ophthalmology Keywords: diabetic retinopathy; cataracts; gold nanoparticles; rutin; antioxidant; early; incipient
Online: 3 August 2023 (02:32:40 CEST)
Diabetic retinopathy (DR) and cataracts (CA) have an early onset in diabetes mellitus (DM) due to the redox imbalance and inflammation triggered by hyperglycemia. Plant-based therapies are characterized by low bioavailability in ocular tissues. The study aimed to investigate the effect of gold nanoparticles phytoreduced with Rutin (AuNPsR), as a possible solution. Insulin, Rutin, and AuNPsR, were administered to an early, six-week rat model of DR and CA. Oxidative stress (MDA, CAT, SOD) was assessed in serum and eye homogenates, and inflammatory cytokines (IL-1 beta, IL-6, TNF alpha) were quantified in ocular tissues. Fundus of retinal arterioles, retina histopathology and lens transmission electron microscopy (TEM), were also performed. DM was linked to constricted retinal arterioles, reduced endogen antioxidants, and eye inflammation. Histologically, retinal wall thickness decreased. TEM showed increased lens opacity and fiber disorganization. Rutin improved retinal arteriolar diameter, while reducing oxidative stress and inflammation. Retinas were moderately edematous. Lens structure was preserved on TEM. Insulin restored retinal arteriolar diameter, while increasing MDA, and amplifying TEM lens opacity. The best outcomes were obtained for AuNPsR, as it improved fundus appearance of retinal arterioles, decreased MDA formation and increased antioxidant capacity. Retinal edema and disorganization in lens fibers were still present.
ARTICLE | doi:10.20944/preprints202307.1883.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: antibacterial; antioxidant; anti-inflammatory activity; E. radiata; E. cinerea
Online: 27 July 2023 (08:19:02 CEST)
Eucalyptus, a therapeutic plant mentioned in the ancient Algerian pharmacopeia, specifically two species belonging to the Myrtaceae family - E. radiata and E. cinerea, were investigated in this study for their antibacterial, antioxidant, and anti-inflammatory properties. The study used aqueous extracts (AE) obtained from these plants, and the extraction yields were found to be dif-ferent. The in vitro antibacterial activity was evaluated using a disc diffusion assay against three typical bacterial strains. The results showed that E. radiata EAq was effective against all three strains, while E. cinerea EAq was only effective against E. coli. Both extracts displayed significant antioxidant activity compared to BHT. The anti-inflammatory impact was evaluated using a pro-tein (BSA) inhibition denaturation test. The E. radiata extract was found to inhibit inflammation by 75% at a concentration of 250 g/ml, significantly higher than the placebo. Ellagic acid, a pri-mary phytochemical found in the extracts, demonstrated noteworthy toxic and pharmacokinetic characteristics and a maximum binding energy of -7.53 kcal/mol for its anti-TyrRS activity in sili-co. The study suggests that the extracts and their primary phytochemicals could enhance the effi-cacy of antibiotics, antioxidants, and non-steroidal anti-inflammatory drugs (NSAIDs). As phar-maceutical engineering experts, we believe this research contributes to developing natural-based drugs with potential therapeutic benefits.
ARTICLE | doi:10.20944/preprints202307.0222.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: neuropathic pain; honokiol; Magnolia officinalis; antioxidant; cannabinoid receptor; neuroinflammation
Online: 4 July 2023 (12:14:02 CEST)
Neuropathic pain (NP) affects about the 8% of the general population. Current analgesic therapies have limited efficacy, making NP one of the most difficult to treat pain conditions. Evidence indicates that excessive oxidative stress can contribute to the onset of chronic NP and several natural antioxidant compounds have showed promising efficacy in NP models. Thus, the aim of the present study was to investigate the pain-relieving activity of honokiol (HNK)-rich standardized extract of Magnolia officinalis Rehder & E. Wilson bark (MOE), well known for its antioxidant and anti-inflammatory properties, in the spared nerve injury (SNI) model. The molecular mechanisms were investigated in spinal cord samples from SNI mice and in LPS-stimulated BV2. MOE and HNK showed antioxidant activity. MOE (30 mg/kg p.o.), produced an antiallodynic effect in the absence of locomotor impairment. MOE treatment reduced spinal p-p38, p-JNK1, iNOS, p-p65, IL-1ß and Nrf2 overexpression, increased IL-10 and MBP levels and attenuated the Notch signaling pathway by reducing Jagged1 and NEXT. All these effects were prevented by the CB1 antagonist AM251. HNK reduced the proinflammatory state of LPS-stimulated BV2 cells and reduced Jagged1 overexpression. MOE and HNK, by modulating oxidative and proinflammatory responses, might represent interesting candidates for NP management.
REVIEW | doi:10.20944/preprints202307.0110.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: type-2 diabetes mellitus; polyphenols; oxidative stress; antioxidant capacity
Online: 3 July 2023 (14:22:55 CEST)
Type-2 diabetes mellitus is recognized as a serious public health concern with a considerable impact on human life, long-term health expenditures, and substantial health losses. In this context, the use of dietary polyphenols to prevent and manage Type 2 diabetes mellitus is widely documented. These dietary compounds exert their beneficial effects by several actions, including the protection of pancreatic islet β-cell, the antioxidant capacities of these molecules, their effects on insulin secretion and actions, the regulation of intestinal microbiota, and their contribution to ameliorating diabetic complications, particularly those of vascular origin. In the present review, we intend to highlight these multifaceted actions and the molecular mechanisms by which these plant-derived secondary metabolites exert their beneficial effects on type-2 diabetes patients.
REVIEW | doi:10.20944/preprints202306.2234.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: atopic dermatitis; antioxidant agents; oxidative stress; reactive oxygen species
Online: 3 July 2023 (03:12:41 CEST)
Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by itching, impaired epidermal barrier function and unbalanced inflammatory response. The pathophysiology involves immune dysregulation, with a predominance of T-helper 2 cells. AD is triggered by many known and unknown factors, including oxidative stress. Reactive oxygen species (ROS) contribute to AD pathogenesis by causing cellular damage and inflammation. Moreover, increased oxidative stress in AD leads to hyperactivation of the MAP kinase pathway, extracellular signal-regulated kinase (ERK) and p38, with DNA damage and subsequent skin barrier dysfunction. This narrative review provides a comprehensive overview of the role of natural antioxidant compounds, highlighting their potential therapeutic value in AD management. They include vitamin D, vitamin E, pyridoxine (vitamin B6), Vitamin C, carotenoids and melatonin, in AD. Despite some studies have shown an association between vitamin D, vitamin E, vitamin C and carotenoids levels and AD course, conflicting results exist. Pyridoxine supplementation has shown mixed results, and melatonin has demonstrated antioxidant and anti-inflammatory properties in AD; in fact, melatonin treatment resulted in a decrease in symptoms in patients with AD, although no significant correlation with changes in sleep latency was reported. In addition, iron and zinc (Zn) supplementation can also improve AD symptoms. Further research is needed to elucidate the optimal use of these natural antioxidants in AD treatment
REVIEW | doi:10.20944/preprints202306.1706.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Antioxidant activity; autopolyploidy; legumes; salinity stress; reactive oxygen species.
Online: 25 June 2023 (03:41:56 CEST)
Salinity stress affect plant growth and development by causing osmotic stress, and nutrient imbalances through excess Na+, K+ and Cl- ion accumulations that induce toxic effects during germination, seedling development, vegetative growth, flowering, and fruit set. However, the effects of salt stress on such processes, especially in polyploidised leguminous plants remains unexplored and scantly reported compared to their diploid counterparts. This paper discusses the physiological and molecular response of legumes towards salinity stress based osmotic and ionic imbalances in plant cells. A multigenic response involving various compatible solutes, osmolytes, ROS, polyamines and antioxidant activity, together with genes encoding proteins involved in the signal transduction, regulation and response mechanisms to this stress were identified and discussed. This discussion reaffirms polyploidisation as the driving force in plant evolution and adaptation to environmental stress constraints such as drought, feverish temperatures, and in particular, salt stress. As a result, thorough physiological and molecular elucidation of the role of gene duplication through induced autopolyploidisation and possible mechanisms regulating salinity stress tolerance in grain legumes must be further studied.
ARTICLE | doi:10.20944/preprints202305.1613.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: Origanum onites L.; natural products; liposomes; antioxidant activity; mice
Online: 23 May 2023 (08:09:49 CEST)
In the present study the effects of Origanum onites L. extract and essential oil of O. onites L. on the antioxidant status of the liver and brain of mice were investigated. Due to certain disadvantages of essential oils, such as poor solubility, high volatility, sensitivity to UV light and heat, formulation of liposomes with Oregano essentials (OE) was optimized and used in this study. The results demonstrated that the best composition of the lipid carriers and Oregano essentials were conducted in terms of the PDI, mean particle size and EE. The LE4 formulation contained Lipoid S100 of 45 mg, Lipoid S75 of 45 mg and 90 mg of EO. The administration of O. onites L. extract to mice for 21 days significantly decreased glutathione (GSH) level in the liver and brain of mouse as well as malondialdehyde (MDA) concentration in the liver. In the brain of mice MDA level significantly increased after this extract consumption. Whereas liposomes with OE significantly decreased GSH concentration in mouse brain and MDA concentration in mouse liver but increased (p>0.05) GSH level in liver and MDA concentration in brain of mice compared with the control group. It was investigated that both, O. onites L. extract as well as liposomes with OE of this plant material make changes in the antioxidant status in the liver and brain of mice.
ARTICLE | doi:10.20944/preprints202305.1321.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: Abricó de macaco; antioxidant potential; chemistry characterization; dentistry; microbiology
Online: 18 May 2023 (10:08:10 CEST)
The study of phytotherapy in dentistry is relevant due to the low occurrence of research in the treatment of oral pathologies, such as caries and periodontal disease. Thus, the aim of this research was to characterize the chemical composition of extracts from the leaves of Couroupita guianensis Aubl, including toxicological evaluation and the antioxidant and antimicrobial potential against Staphylococcus aureus, Streptococcus mutans and Candida albicans. Three extracts were prepared using assisted ultrasound, originating the Crude Ultrasound Extract (CUE) and Soxhlet apparatus, originating the Crude Soxhlet Extract (CSE) and the Ethanol Soxhlet Extract (ESE). In the analysis of the chemical composition, the presence of flavonoids, tannins and saponins were detected. LC-DAD analysis revealed the presence of caffeic acid, sinapic acid, rutin, quercetin, luteolin, kaempferol and apigenin in all extracts. In the GC-MS analysis, stigmasterol and β-sitosterol were identified in CUE and CSE. The antioxidant potentials, determined by the DPPH• and ABTS•+ methods, the ESE showed higher antioxidant activity (2.98 ± 0.96 and 4.93 ± 0.90, respectively). In the evaluation of toxicity, the CUE 50µg/mL and the ESE 50 µg/mL presented growth stimulation of Allium cepa roots. At a concentration of 750µg/mL, all extracts inhibited root growth. None of the extracts showed toxicity against Artemia salina. Antibacterial action was detected in all extracts, mainly against the microorganisms S. aureus and S. mutans; however, the antifungal action against C. albicans was not detected. From the results, the extracts of C. guianensis have therapeutic potential for use in the control of microorganisms in the oral microbiota.
ARTICLE | doi:10.20944/preprints202305.0405.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: phytochemicals; extraction; ethanol/water; antioxidant; anticancer; DPPH, FRAP; Morin
Online: 6 May 2023 (09:42:55 CEST)
Phytochemicals are gaining popularity due to their antioxidant effects and potential protection against inflammation, cardiovascular disease, and certain types of cancer. The retention of these phytochemicals during extraction must be maximized. This research focused on extracting bioactive compounds from Psidium guajava Linn leaves using solvent extraction (SE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) with distilled water (DW) or 60% (v/v) ethanol/water (ET). Phytochemical screening demonstrated that all of the screening showed positive results in all extraction methods, except glycoside. There were no significant (p>0.05) differences in total phenolic (TPC) and flavonoid content (TFC) during MAE, SE, and UAE in case of ET. However, SE shows better (p<0.05) extraction of TPC and TFC than UAE and MAE in case of DW. ET shows better (p<0.05) extraction of TPC and TFC than DW. Antioxidant analysis shows the same trend though both DPPH and FRAP values were higher in MAE and SE for ET and DW, respectively. MAE/ET showed the highest inhibitory activity and dose-dependent response using SW480 cell via MTT assay. HPLC and TLC analysis reveal the fingerprint of morin, might function as an anticancer agent. In conclusion, MAE/ET is the most efficient among the extraction techniques in terms of anticancer activity.
ARTICLE | doi:10.20944/preprints202304.0512.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: grape skins; seeds; polyphenolic composition; antioxidant potential; RT-HPLC
Online: 18 April 2023 (10:22:09 CEST)
Abstract: The aim of this study was to identify and quantify polyphenolic compounds in skin extracts from four Bulgarian grape varieties and compare to those of seed extracts. The values of total phenolic contents (TPC), flavonoids, anthocyanins, procyanidins, ascorbic acid in grape skin extracts were determined. The antioxidant capacities of skin extracts were evaluated by DPPH, ABTS, FRAP and CUPRAC methods. The TPC values of skin extracts were 2-3 times lower than those of seed extracts. The significant difference between total parameters values of individual grape varieties were also found. According to the TPC and antioxidant capacity of skin extracts the different grape varieties were in the following order: Marselan ≥ Pinot Noir ˃ Cabernet Sauvignon ˃ Tamyanka. The individual compounds in the grape skin extracts were determined by RP-HPLC and compared with those of seed extracts. The determined composition of skin extracts was significant different from seed extracts composition. Qualitative and quantitative evaluation of the procyanidins and catechins in the skins were carried out. A correlation between phenolic contents, individual composition and antioxidant capacity of different extracts was found. The studied grape extracts have a potential to be applied as natural antioxidants in the pharmaceutical and food industries.