ARTICLE | doi:10.20944/preprints202001.0157.v3
Subject: Life Sciences, Biochemistry 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.
REVIEW | doi:10.20944/preprints202205.0197.v1
Subject: Life Sciences, Other 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/preprints201812.0050.v1
Subject: Medicine & Pharmacology, Pharmacology & 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/preprints202201.0095.v2
Subject: Chemistry, General & Theoretical Chemistry Keywords: antioxidant activity; eearomatization; frontier molecular orbital; fukui function f0; DFT
Online: 3 February 2022 (15:19:51 CET)
This study reports a computational investigation on the antioxidant activity of five plant food benzoic acid derivatives, namely gallic acid (GA), para-hydroxybenzoic acid (PHBA), protocatechuic acid (PCA), syringic acid (SA), and vanillic acid (VA). Based on computed thermodynamics parameters, a detailed comparative debate is developed concerning their free radical scavenging activity in the gas phase and polar solutions (in water and methanol solvents). This discussion goes on to elucidate both the most preferred mechanism and the order of antioxidant activity for these molecules in each environment. Paradoxically, calculations using the harmonic oscillator model of aromaticity (HOMA) suggest that H abstraction radicals gain in stability as the central benzene ring loses in structural aromaticity. Finally, spin densities and fukui function f0 seem to be good indicators of the local reactivity of these compounds towards free radicals.
ARTICLE | doi:10.20944/preprints202009.0231.v1
Subject: Chemistry, 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/preprints202105.0371.v1
Subject: Materials Science, Biomaterials Keywords: carboxymethy chitosan; corn peptide; antioxidant activity; antibacterial activity; film
Online: 17 May 2021 (07:59:06 CEST)
Active films based on carboxymethyl chitosan incorporated corn peptide were developed. Physicochemical properties of the films, including thickness, opacity, moisture content, color, mechanical properties, water vapor permeability, and oil resistance, were measured. Biological activities of the films, including the antioxidant and antibacterial activities, were characterized in terms of 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging activity, reducing power, the total antioxidant activity, and the filter disc inhibition zone method. The results indicated that the incorporation of corn peptide caused interactions between carboxymethyl chitosan and corn peptide in Maillard reaction and gave rise to the films light yellow appearance. Compared with the Control, the degree of glycosylation, browning intensity, thickness, opacity, tensile strength, antioxidant activity, and antibacterial activity of films were increased, but the elongation, vapor permeability, and oil resistance of films were decreased. The films based on corn peptide and carboxymethyl chitosan can potentially be applied to food packaging.
ARTICLE | doi:10.20944/preprints202102.0282.v1
Subject: Chemistry, Analytical Chemistry Keywords: Fuscoporia torulosa; triterpenes; cytotoxic; antioxidant; synergism; antibacterial; ORAC; DPPH
Online: 11 February 2021 (11:45:31 CET)
Investigation of the methanol extract of the poroid fungus Fuscoporia torulosa resulted in the isolation of a novel triterpene, fuscoporic acid (1) together with inoscavin A and its previously undescribed Z isomer (2 and 3), 3,4-dihydroxy-benzaldehide (4), osmundacetone (5), senexdiolic acid (6), natalic acid (7), and ergosta-7,22-diene-3-one (8). The structures of fungal compounds were determined on the basis of NMR and MS spectroscopic analysis, as well as molecular modelling studies. Compounds 1, 6-8 were examined for their antibacterial properties on resistant clinical isolates, and cytotoxic activity on human colon adenocarcinoma cell lines. Compound 8 was effective against Colo 205 (IC50 11.65±1.67 µM), Colo 320 (IC50 8.43±1.1 µM) and MRC-5 (IC50 7.92±1.42 µM) cell lines. Potentially synergistic relationship was investigated between 8 and doxorubicin, which revealed a synergism between the examined compounds with a combination index (CI) at the 50% growth inhibition dose (ED50) of 0.521±0.15. Several compounds (1, and 6-8) were tested for P‐glycoprotein modulatory effect in Colo 320 resistant cancer cells, but none of the compounds proved to be effective in this assay. Fungal metabolites 2-5 were evaluated for their antioxidant activity using the oxygen radical absorbance capacity (ORAC) and DPPH assays. Compounds 4 and 5 proved to possess considerable antioxidant effect with EC50 0.25±0.01 (DPPH) and 12.20±0.92 mmol TE/g (ORAC). The current article provides valuable information on both chemical and pharmacological profiles of Fuscoporia torulosa, paving the way for future studies with this species.
ARTICLE | doi:10.20944/preprints202012.0453.v1
Subject: Biology, Anatomy & Morphology Keywords: Actinidia arguta; leaf; bioactivity; antioxidant activity; LC-MS/MS
Online: 18 December 2020 (11:14:24 CET)
Actinidia arguta (Sieb. et Zucc.) Planch. ex Miq. is abundant of vitamin C and bioactive compounds with high antioxidant activities. In this study, eight wild A. arguta accessions from different areas in Northeast China were collected. Some bioactive compounds were examined on the different tissues of different germplasms including four kinds of leaves, petioles and fruits. The method of UPLC-MS was used to detect the flavonoid compounds. The results showed that some bioactive compounds including vitamin C, soluble sugar, free amino acid, total phenolics and flavonoids content showed significant differences between six tissues of A. arguta accessions and showed significant variability with maturity. In eight accessions, the highest vitamin C content was found in young apical leaves of ‘CBS-6’ (7.47 mg/g fresh weight), and the highest soluble sugar content was in fruits of ‘CJ-1’ (196.52 mg/g fresh weight) and the highest total phenolic content and total flavonoids content were in young apical leaves of ‘CBS-11’ (3.48 mg/g fresh weight) and of ‘CBS-3’ (2.00 mg/g fresh weight), respectively. Ten flavonoid compounds including kaempferol, isorhamnetin and quercetin were detected in leaves, petioles and fruits. The total content of flavonoids were highest in young apical leaves (10219.84 µg·g-1) and the lowest in fruits (78.75 µg·g-1). Based on the comparison of the contents of several bioactive compounds, the two accessions ‘CJ-1’ and ‘CBS-8’ had relatively outstanding performance, and in the comprehensive evaluation of the antioxidant activity among different tissues, the young leaves had the strongest antioxidant activity. These results highlighted the antioxidant potentialities of A. arguta leaves as a major source of phenolics and vitamin C as well as flavonoids. It provided a theoretical basis for the utilization of leaves of A. arguta.
ARTICLE | doi:10.20944/preprints201609.0037.v1
Subject: Biology, Plant Sciences Keywords: Consolida orientalis; ethyl acetate extract; antioxidant activity; β-sitosterol
Online: 9 September 2016 (11:18:02 CEST)
General phytochemical screening of the aerial parts of Consolida orientalis revealed the presence of steroids, terpenes, phenolic compounds, saponins, fatty acids, alkaloids. This study was conducted to investigate the bioactivities of extracts, isolation and identification the compounds from aerial parts of C.orientalis. The main goal of the present study is identifying and characterizing the antioxidant activity of the Consolida orientalis and biological isolation of active terpenoid. Aerial parts of the plant were dried at room temperature and reduced to small pieces, followed by using extraction with ethyl acetate percolation. Tree complementary analysis system was used, DPPH free radical scavenging test, total phenolic metabolites and FRAP. The total phenolic content was 38.83±2.09 mg gallic acid corresponding to g-1 extract with regarding to standard curve (y=0.0054x+0.0488, r2=0.995). IC50 value for DPPH radical – scavenging was 987.11±28.66 mgml-1. The extract was exhibited a medium reducing power compared with Vit C. The isolation and purification was afforded white crystalline powder which was subjected to physical, chemical and spectral identification by IR, 1H- and 13C- NMR and GC-MS. Isolated compound was identified as β-sitosterol. That is a terpenoid with melting point 133.4-134.5 ͦ c and with molecular formula C29H50O.
Subject: Medicine & Pharmacology, Allergology Keywords: galangin; Self microemulsion drug delivery system; Antioxidant damage; Pharmacokinetics
Online: 15 June 2021 (15:30:12 CEST)
Galangin(Gal) is a natural active flavonoid compound separated from the roots and rhizomes of Alpinia ofcinarum Hance. Modern pharmacological studies have shown that Gal has a variety of biological activities such as anti-tumor, anti-fungal, anti-bacterial, anti-inflammatory, anti-ischemic stroke, suppressing vitiligo and Alzheimer’s disease, etc. The purpose of this research was to prepare a galangin self-microemulsion drug delivery system (Gal-SMEDDS) and compare its anti-oxidant activity and pharmacokinetics with free Gal.The average particle size of the prepared Gal-SMEDDS was approximately 21.33 nm, the polydispersity index was 0.096, the zeta potential was -4.09 mV, and the entrapment efficiency was 96.74%. Compared with free Gal, the release of Gal-SMEDDS was improved in vitro release experiment. Cell experiments showed that Gal had obvious anti-oxidation effect, and the effect of Gal-SMEDDS was better than that of free Gal. In vivo pharmacokinetic experiments showed that the pharmacokinetic parameters of Gal-SMEDDS were better than that of free Gal, which indicated that the self-microemulsion drug delivery system(SMEDDS) effectively increases the oral bioavailability of Gal and alters its pharmacokinetic parameters, such that it may be effective in the treatment of anti-oxidant.
ARTICLE | doi:10.20944/preprints201812.0027.v1
Subject: Chemistry, Medicinal Chemistry Keywords: Rumex tunetanus; Phenolic compounds; Metabolic profiling; Antioxidant activity; RP-UHPLC-ESI-QTOF-MS
Online: 3 December 2018 (13:58:52 CET)
The present study was designed to investigate the bioactive compound in Rumextunetanus extracts (polygonaceae), a plant growing in GarâaSejnane region (NW-Tunisia). Hydro-methanol extracts of flowers and stems of Rumextunetanus were analyzed by RP-UHPLC-ESI-QTOF-MS in the negative mode to identify the maximum of bioactive compounds. Applied the aforementioned method, a total of 60 bioactive compounds were characterized for the first time in Rumextunetanus between them, 18 photochemical were firstly identified in the Polygonaceae family in negative ionization mode. Quantification of the identified compounds revealed that quercetin-3-O-glucuronide and (-)-epicatechingallate were the most abundant phenolic compounds in flowers and stems, respectively. Moreover, positive correlations were found between the antioxidant activity measured by DPPH and FRAP assays with the total phenolic compounds (r = 0.98; r = 0.99, respectively) and the abundance of some phenolic subfamilies such as hydroxycinnamic acids, hydroxybenzoic acids, flavonols and flavones with r > 0.86. The compounds displaying significant (P < 0.01) and good correlations with the antioxidant activity (r > 0.93) were hydroxybenzoic acid, rutin, quercetin-3-O-glucuronide, quercetin-3-O-glucoside, quercetin and luteolin-7-O-rutinoside. In addition, the flowers and stems of Rumex tunetanus showed different bioactive compound profiles and significant antioxidant properties of extracts. These results highlight the potential of the RP-UHPLC-ESI-QTOF-MS and MS/MS system to identify untargeted metabolic profiling of Rumex tunetanus. Overall, these results contribute to the clear explanation of the past and current usage of genus Rumex in folk medicine. Future investigations are necessary to develop purified antioxidant extracts, with the application of more selective extraction techniques.
ARTICLE | doi:10.20944/preprints201701.0084.v1
Subject: Chemistry, Food Chemistry Keywords: onions; A. × cornutum; A. cepa; phenolic compounds; antioxidant activity; genotoxicity; antimutagenic activity; antiproliferative activity
Online: 19 January 2017 (02:09:32 CET)
Here we report a comparative study of the pyhtochemical profile and a biological activity of the two onion extracts, namely A. cepa L. and A. × cornutum (Clementi ex Visiani 1842). Identification of flavonoids and anthocyanins and their individual quantities were determined by high performance liquid chromatography (HPLC). The potency of both extracts to scavenge free radicals was determined by DPPH (2,2'-diphenyl-1-picrylhydrazyl) radical-scavenging activity and oxygen radical absorbance capacity (ORAC) methods. DNA protective role was further tested by single-cell gel electrophoresis (COMET) assay and by Fenton’s reagent causing double strand brakes on pUC19 plasmid. In the presence of both extracts, a significant decrease in the DNA damage was observed, which indicates a protective role of A. cepa and A. × cornutum on the DNA strand brakes. Additionally, cytotoxicity was tested on glioblastoma and breast cancer cell lines. The results showed that both extracts had antiproliferative effect, but the most prominent decrease in cellular growth was observed with glioblastoma cells
ARTICLE | doi:10.20944/preprints201808.0548.v1
Subject: Biology, Plant Sciences Keywords: Origanum vulgare; Spodoptera littoralis; terpenoid biosynthesis; larval survival; antioxidant enzyme activity and gene expression; toxicity
Online: 31 August 2018 (13:28:51 CEST)
Terpenoids are toxic compounds produced by plants as a defense strategy against insect herbivores. We tested the effect of Origanum vulgare terpenoids on the generalist herbivore Spodoptera littoralis and the response of the plant to herbivory. Terpenoids were analyzed by GC-FID and GC-MS and quantitative gene expression (qPCR) was evaluated on selected plant genes involved in both terpene biosynthesis. The insect detoxification response to terpenes was evaluated by monitoring antioxidant enzymes activity and expression of insect genes involved in terpene detoxification. O. vulgare terpenoid biosynthesis and gene expression was modulated by S. littoralis feeding. The herbivore-induced increased level of terpenoids (particularly carvacrol and p-cymene) interacted with the herbivore by decreasing larval survival and growth rate. The assimilation by S. littoralis of more than 50% of ingested terpenes correlated with the possible toxic effects of O. vulgare terpenoids. In choice test experiments, carvacrol and γ-terpinene mediated the larval feeding preferences, wherease the prolonged feeding on O. vulgare terpenoids (particularly on γ-terpinene) exerted relevant antinutritional effects on larvae. S. littoralis was found to react to O. vulgare terpenoids by increasing its antioxidant enzymes activities and gene expression, although this was not sufficient to sustain the toxicity of O. vulgare terpenoids.
ARTICLE | doi:10.20944/preprints201711.0082.v1
Subject: Keywords: fatty hydroxamic acids; synthesis; spectroscopy; antioxidant activity; cytotoxic activity; biological targets; ADMET; safety profile
Online: 14 November 2017 (04:42:18 CET)
A fatty hydroxamic acid (FHA) mixture synthesized from olive oil triacylglycerides by hydroxylaminolysis and composed predominantly of oleyl and linoleyl hydroxamic acid (OHA and LHA, respectively) was characterized by means of IR, Raman, MS and 1D and 2D 1H- and 13C-NMR spectroscopy. The ratio of OHA and LHA (4:1) was confirmed by MALDI TOF/TOF mass spectrometry. The radical scavenging and the Fe2+-chelating activity, as well as antioxidant activity in β-carotene-linoleic acid and the Fe3+-reducing power assays of the FHAs yielded positive results. The results of FHA cell toxicity on normal fibroblast (BJ) and a tumour cell line (HeLa) revealed that the normal cell line was sensitive to FHAs within the entire range of applied concentrations (5 × 10−4 mg/mL to 5 × 10−1 mg/mL), while the HeLa tumour cell line was sensitive only at the highest FHA concentration (5 × 10−1 mg/mL). In silico target prediction indicated cannabinoid receptors 1 and 2, the fatty-acid amide hydrolase 1 and hystone deacetylases as the most probable targets of OHA and LHA. According to ADMET predictor analysis, the safety profiles of OHA and LHA are comparable to that of SAHA (vorinostat) the histone deacetylase inhibitor in use as an antineoplastic and immunomodulating agent.
ARTICLE | doi:10.20944/preprints201808.0060.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: eggplant peel; polyphenols; HSV-1; Warburg effect; antioxidant activity; antiviral agents; vegetable waste
Online: 3 August 2018 (04:53:37 CEST)
DR2B and DR2C extracts, from peel of commercially and physiologically ripe eggplants, were studied for the antioxidative cytoprotective properties and anti-HSV-1 activity, in line with the evidence that several antioxidants can impair viral replication by maintaining reducing conditions into the host cells. The antioxidative cytoprotective effects against tBOOH-induced damage was assessed in Caco2 cells, while the antiviral activity was studied in Vero cells; phenolic and anthocyanin fingerprint was characterized by integrated phytochemical methods. Results highlighted different compositions of the extracts, with chlorogenic acid and delphinidin-3-rutinoside as the major constituents; other peculiar phytochemicals were also identified. DR2C resulted able to partly counteract the tBOOH-induced cytotoxicity, with a remarkable lowering of lactate metabolism under both normoxia and hypoxia. DR2B and DR2C reduced ROS production, possessed scavenging and chelating properties. Interestingly, DR2C increased intracellular GSH levels. Furthermore, DR2C inhibited the HSV-1 replication when added for 24 h after viral adsorption, as also confirmed by the reduction of many viral proteins expression. Since DR2C was able to reduce NOX4 expression during HSV-1 infection, its antiviral activity may be correlated to its antioxidant properties. Although further studies are needed to better characterize DR2C activity, the results suggest this extract as a promising new anti-HSV-1 agent.
ARTICLE | doi:10.20944/preprints202012.0414.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: galantamine; curcumin; in vivo AChE inhibition; acute toxicity in mice; antioxidant activity; malondialdehide levels; glutathione levels; brain homogenate; complete blood count; biochemical serum parameters
Online: 16 December 2020 (13:45:10 CET)
The acetylcholinesterase (AChE) inhibitors are the main drugs for symptomatic treatment of neurodegenerative disorders like Alzheimer’s disease. A recently designed, synthesized and tested hybrid compound between the AChE inhibitor galantamine (GAL) and the antioxidant polyphenol curcumin (CU) showed high AChE inhibition in vitro. Here, we describe tests for acute and short-term toxicity in mice as well as antioxidant tests on brain homogenates measured the levels of malondialdehide (MDA) and glutathione (GSH). Haematological and serum biochemical analyses were also performed. In the acute toxicity tests, the novel AChE inhibitor given orally in mice showed LD50 of 49 mg/kg. The short-term administration of 2.5 and 5 mg/kg did not show toxicity. In the ex vivo tests, the GAL-CU hybrid performed better than GAL and CU themselves. In a dose of 5 mg/kg, it demonstrates 25% reduction in AChE activity, 28% and 73% increase in the levels of MDA and GSH, respectively. No significant changes in blood biochemical data were observed. The GAL-CU hybrid is a novel non-toxic AChE inhibitor with high antioxidant activity which makes it a perspective multitarget drug candidate for treatment of Alzheimer’s disease.
ARTICLE | doi:10.20944/preprints201701.0036.v1
Subject: Biology, Plant Sciences Keywords: Acer truncatum leaves; ultrasonic-assisted extraction; response surface methodology; phenolics; antioxidant activity; UPLC-QTOF-MS/MS
Online: 9 January 2017 (04:16:01 CET)
This study was designed for the first time to improve phenolic yield and antioxidant activity of ultrasonic-assisted extraction from Acer truncatum leaves (ATL) using response surface methodology, and phenolic composition in ATL extracted under the optimized condition were characterized by UPLC-QTOF-MS/MS. Solvent and extraction time were selected based on preliminary experiments, and a four-factors-three-levels central composite design was conducted to optimize solvent concentration (X1), material-to-liquid ratio (X2), ultrasonic temperature (X3) and power (X4) for an optimal total phenol yield (Y1) and DPPH• antioxidant activity (Y2). The results showed that the optimal combination was ethanol: water (v:v) 66.21%, material-to-liquid ratio 1:15.31 g/mL, ultrasonic temperature 60 °C, power 267.30 W, and time 30 min with three extractions, giving a maximal total phenol yield of 7593.62 mg gallic acid equivalent /100 g d.w. and a maximal DPPH• antioxidant activity of 74241.61 μmol Trolox equivalent/100 g d.w.. Furthermore, 22 phenolics were first identified in ATL extract obtained under the optimized conditions, indicating that gallates, gallotannins, quercetin, myricetin and chlorogenic acid derivatives were the main phenolic composition in ATL. What’s more, a gallotannins pathway existing in ATL from gallic acid to penta-O-galloyl-glucoside was interpreted. All these results provided practical information aiming at full utilization of phenolics in ATL, together with fundamental knowledge for further research.
ARTICLE | doi:10.20944/preprints201907.0055.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Barhi date palm kernels (BDPK); non-extractable polyphenols (NEPP); anticancer activity; antioxidant activity; response surface methodology; optimisation.
Online: 3 July 2019 (09:23:01 CEST)
Dietary polyphenols exist in two forms; extractable polyphenols (EPP) or compounds solubilised by aqueous/organic solvents, and non-extractable polyphenols (NEPP) or compounds remain in the corresponding residues after the extraction. At present, most researchers focus on EEP fractions, while NEPP is neglected. Thus, this study aimed to release NEPP from the remaining powder residue of Barhi date palm kernels (BDPK) with acid hydrolysis. The related extraction conditions were determined and optimised using response surface methodology (RSM) for maximisation of NEPP with highest cytotoxic and antioxidant activities. The face-centred central composite design (FCCCD) was used to establish treatments based on three independent variables, namely; extraction temperature, time, and solvent/sample ratio. Under the optimal conditions, the experimental values for DPPH radical-scavenging capacity of NEPP (IC50=57.52µg/mL), and cytotoxicity of NEPP against A549 and HT29 cells were IC50=17.4 µg/mL and 31.4µg/mL, respectively. The experimental values were in agreement with those predicted by RSM models, confirming the suitability of the model employed and the success of RSM for optimisation of the extraction conditions for NEPP from BDPK. These results indicate that NEPP from industrial date fruit waste could be a promising candidate as natural antioxidants with significant antiproliferation effect against A549 and HT29 cancer cells in-vitro.
ARTICLE | doi:10.20944/preprints202104.0603.v2
Subject: Biology, Anatomy & Morphology Keywords: Phagnalon saxatile subsp. Saxatile; phenolic compounds; polarity; antioxidant activities; UPLC-DAD-ESI-MSn; chlorogenic acids
Online: 26 April 2021 (12:23:33 CEST)
Phagnalon saxatile subsp. saxatileest une espèce sauvage très répandue en Algérie qui est utilisée à des fins médicinales comme analgésique et anticholestérolémique. Cependant, les informations sur son contenu phytochimique sont encore rares. L'objectif de cette étude était d'identifier et de quantifier les composés phénoliques de différents extraits de ses tiges feuillues. A cet effet, les effets de quatre solvants d'extraction ont été étudiés sur la teneur en composés phénoliques et l'activité antioxydante de cette plante. Les extraits préparés avec des solvants polaires (méthanol et eau) contenaient des quantités plus élevées de composés phénoliques et présentaient une meilleure activité antioxydante que les extraits avec des solvants apolaires (hexane, dichlorométhane). L'extrait méthanolique, le plus riche en phénoliques totaux et en flavonoïdes totaux, avait une activité antioxydante significative au regard de la capacité de piégeage du DPPH ° (IC50 de 5,47 µg / mL), Capacité de piégeage ABTS (CI50 de 63,77 µg / mL) et inhibition de l'oxydation de l'acide linoléique (CI50 de 22,71 µg / mL), par rapport aux antioxydants synthétiques. Les acides chlorogéniques et quelques flavonoïdes ont été identifiés et quantifiés par UPLC-DAD-MSn. Les isomères des acides di-O-caféoylquiniques étaient les composés phénoliques les plus concentrés (25,4 mg / g DW) dans l'extrait méthanolique.
Subject: Life Sciences, Microbiology Keywords: essential oil; Mentha pulegium; Mentha suaveolens; Listeria monocytogenes; Salmonella enterica; antioxidant; sub-lethally injured bacteria
Online: 5 May 2019 (12:05:03 CEST)
The essential oils (EOs) obtained from aromatic plants are rich in natural compounds with interesting biological effects. The aim of this study was to evaluate the chemical composition of EOs of Mentha pulegium (MP-EO) and Mentha suaveolens (MS-EO) collected from Morocco, and their antioxidant properties and antibacterial activity against Salmonella enterica and Listeria monocytogenes. The EOs were extracted by hydro-distillation, while the chemical compositions were determined by GC-MS. The antioxidant activity was evaluated by DPPH and FRAP assay. Antibacterial activity was tested with disc diffusion assay; determination of minimum inhibitory concentration, minimum bactericidal concentration and the evaluation of sub-lethally injured cell were also performed. The results of chemical composition showed the presence of compounds not still reported in EOs obtained from these plants. MS-EO was characterized by the best antioxidant and antibacterial activity vs S. enterica and L. monocytogenes respect to MP-EO. The EOs tested in this study were rich in compounds with interesting activities and they could be applied in the medical fields, as well as in food industries as natural preservatives against tested food borne pathogens.
ARTICLE | doi:10.20944/preprints202205.0296.v1
Subject: Life Sciences, 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/preprints202012.0821.v1
Subject: Medicine & Pharmacology, Allergology 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, 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/preprints201803.0061.v1
Subject: Chemistry, 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.
ARTICLE | doi:10.20944/preprints202008.0541.v1
Subject: Life Sciences, 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: Medicine & Pharmacology, General Medical Research 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, Other 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
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, 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, Agricultural Sciences & 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
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: Life Sciences, Other 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 & Pharmacology, General Medical Research 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/preprints202209.0437.v1
Subject: Biology, Other 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 & Pharmacology, Pharmacology & 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, 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: Life Sciences, Biochemistry 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: Engineering, Biomedical & Chemical Engineering 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, Agricultural Sciences & 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: Medicine & Pharmacology, Other 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, 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, Other 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: Life Sciences, Biochemistry 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: Life Sciences, Biochemistry 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: Materials Science, General Materials Science 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
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: Medicine & Pharmacology, Nutrition 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 & Pharmacology, Pharmacology & 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/preprints202207.0258.v1
Subject: Biology, 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 & Pharmacology, Pharmacology & 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: Life Sciences, Immunology 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, Anatomy & Morphology 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, 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, 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 & Pharmacology, Allergology 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/preprints202005.0254.v1
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, 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: Life Sciences, Other 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, Other 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 & Pharmacology, Pharmacology & 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/preprints201811.0283.v1
Subject: Medicine & Pharmacology, Pharmacology & 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, 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, 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, Other 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, 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.
REVIEW | doi:10.20944/preprints202209.0464.v1
Subject: Life Sciences, Other Keywords: wheat aleurone; dietary fibre; extraction process; antioxidant; bread; arabinoxylans
Online: 29 September 2022 (09:00:46 CEST)
The wheat aleurone layer is, according to millers, the main bran fraction. It is a source of nutritionally valuable compounds, such as dietary fibres, proteins, minerals and vitamins, that may exhibit health benefits. Despite these advantages, the aleurone layer is scarce on the market, probably due to issues related to its extraction. Many processes exist with some patents, but a choice must be made between the quality and quantity of the resulting product. Nonetheless, its potential has been studied mainly in bread and pasta. While the nutritional benefits of aleurone-rich flour addition to bread agree, opposite results have been obtained concerning its effects on end-product characteristics (namely loaf volume and sensory characteristics), thus ensuing different acceptability responses from consumers. However, the observed negative effects of aleurone-rich flour on bread dough could be reduced by subjecting it to pre- or post-extracting treatments meant to either reduce the particle size of the aleurone’s fibres or to change the conformation of its components.
ARTICLE | doi:10.20944/preprints202205.0154.v1
Subject: Biology, Physiology Keywords: antioxidant enzymes; freshwater fish; oxidative stress; PFAS; Veneto region
Online: 12 May 2022 (02:47:28 CEST)
In recent decades, the interest in PFAS has grown exponentially around the world, due to the toxic effects induced by these chemical compounds in humans, as well as in other animals and in plants. However, current knowledge related to the antistress responses that organisms can express when exposed to these substances is still insufficient and therefore it requires further investigation. The present study focuses on antioxidant responses in Squalius cephalus and Padogobius bonelli, exposed to significant levels of PFAS in an area of the Veneto region subjected to a recent relevant pollution case. These two ubiquitous freshwater species were sampled in three rivers characterized by different concentrations of PFAS. Several biomarkers of oxidative stress have been evaluated and the results suggest that PFAS chronic exposure induces some physiological responses in the target species, at both cellular and tissue scales. The risk of oxidative stress seems to be kept under control by the antioxidant system by means of gene activation at the mitochondrial level. Moreover, the histological analysis suggests an interesting protective mechanism against damage to the protein component based on lipid vacuolization.
ARTICLE | doi:10.20944/preprints202112.0166.v1
Subject: Biology, Animal Sciences & Zoology Keywords: methyl sulfonyl methane; sodium sulfate; laying hen; antioxidant capacity
Online: 10 December 2021 (08:32:41 CET)
The present study was conducted to investigate the comparative effects of organic and inorganic forms of sulfur, methyl sulfonyl methane (MSM) and sodium sulfate (SS), on laying performance, egg quality, ileal morphology, ileal volatile fatty acids, and antioxidant and stress markers in various biological samples in aged laying hens. A total of 144, 73-week-old Lohman Brown-Lite laying hens were randomly assigned to one of three experimental diets: basal diet (CONT), CONT + 0.2% MSM (MSM), and CONT + 0.3% SS (SS). The trial lasted for 12 weeks. MSM and SS groups contained 0.07% of sulfur, either organic or inorganic. Dietary MSM did not affect egg production and feed conversion ratio at 12 weeks compared with the CONT group. Dietary sulfur did not affect egg quality except for Haugh unit at 4 weeks which was lowered (P < 0.05) in the SS group. Compared with the CONT group, higher (P < 0.05) villus height and crypt depth ratio was observed in the SS group. None of dietary sulfur affected the percentages of short-chain fatty acids in the ileum. Total antioxidant capacity of liver increased (P < 0.05) in laying hens fed MSM- and SS-added diets compared with the CONT group. The MSM and SS groups lowered (P < 0.05) malondialdehyde (MDA) concentration in serum samples compared with the CONT. Finally, dietary MSM had the lowest (P < 0.05) MDA concentrations in yolk samples. Taken together, our study showed that dietary organic and inorganic sulfur have positive effects on ileal morphology and antioxidant capacity in laying hens. However, SS-mediated inhibition in laying performance needs to be clarified.
ARTICLE | doi:10.20944/preprints202108.0478.v1
Subject: Biology, Plant Sciences Keywords: antioxidant activity; chlorophyll; glycinebetaine; membrane stability index; salt stress
Online: 25 August 2021 (08:19:23 CEST)
Tagetes genus of Composite family consider one of the most favorite floriculture plant. Therefore, of particular interest examine the salt tolerance of this bedding and coloring agent plant. In this research, was report the role of glycinebetaine (GB) in attenuating the adverse impacts of salt stress in African marigold plant, along with their anti-oxidative capacities and biochemical attributes. The salt stressed African marigold (100 and 150 mM NaCl) was treated with GB at 200 mM, beside untreated control plants. According to the obtained results, the growth characters were negatively in salt stressed plants but a mitigate impact of GB were observed in this respect. Obviously, the morphological as well as some physiological characters were reduced with salinity treatments while GB treatment reverses these effects. Overall, the alleviate impact of GB on the negative impact of salt stress was enhanced through improving total phenolic and antioxidant enzyme activity. Further, it is concluded that GB concentration induces the activities of antioxidative enzymes which scavenged ROS increased under saline conditions.
ARTICLE | doi:10.20944/preprints202108.0296.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Ephedra alata; antioxidant activity; anti-inflammatory activity; phytochemical screening
Online: 13 August 2021 (09:23:00 CEST)
Ephedra alata Decne. (Ephedraceae) is a medicinal species commonly used to treat cancers, respiratory diseases, fever, and hypertension. The present study aimed to establish a phytochemical profile, evaluate the antioxidant potential and estimate the anti-inflammatory activities of .. Aqueous and methanolic extracts of E. alata aerial parts were phytochemically investigated using standard methods. DPPH, phosphomolybdenum total antioxidant capacity and reducing power assays were used to evaluate the antioxidant activity. Antioxidant activity was determined using total antioxidant capacity, the scavenging activity of the stable DPPH free radical and ferric reducing antioxidant power assays. The anti-inflammatory activity was determined using egg albumin membrane denaturation and human red blood cells membrane stabilizing assays. The anti-inflammatory potential of E. alata extracts was evaluated using human red blood cells membrane stabilization, egg albumin and BSA albumin denaturation assays. Quinones, anthraquinones, steroids, phytosteroids, phenols, terpenoids, flavonoids, saponins, glycosides, Cardiac glycosides, reducing sugars and anthocyanins were present in the E. alata’s aqueous extract, in addition to coumarins and proteins in the methanolic extract. The highest total phenolic and flavonoid content was recorded in the aqueous extract with 8.66 ±0.09 mg GA/g and 248.04 ±1.47 mg Q/g, respectively. On the other hand, E. alata methanolic extract had the highest tannin content of 62.12 ±0.10 mg C/g. The best radical scavenging activity (IC50 = 4.63±0.00 mg/ml) and total antioxidant capacity were exhibited by the E. alata aqueous (7.35±0.12 mg/ml AAE), whereas the methanolic extract possessed the highest reducing power activity (1.81±0.00 mg AAE/ml). Regarding the anti-inflammatory activities, E. alata methanolic extract exerted the highest HRBC stabilization of 34.72 ±0.08% whereas the aqueous extract exhibited the highest bovine serum and Egg albumin denaturation inhibition of 99.22 ±0.02% and 73.31 ±0.90, respectively. Taken together, our results suggest that E. alata aerial parts aqueous and methanolic extracts can be utilized as future antioxidants and anti-inflammatory ethnomedicines owing to their rich bioactive molecules content.
REVIEW | doi:10.20944/preprints202107.0361.v1
Subject: Medicine & Pharmacology, Allergology Keywords: wound healing; oxidative stress; antioxidant dressing; reactive oxygen species.
Online: 15 July 2021 (13:32:15 CEST)
(1) Background: Reactive oxygen species (ROS) play a crucial role in the preparation of the normal wound healing response. Therefore, a correct balance between low or high levels of ROS is essential. Antioxidant dressings that regulate this balance is a target for new therapies. The purpose of this review is to identify the compounds with antioxidant properties that have been tested for wound healing and to summarize the available evidence on their effects. (2) Methods: A literature search was conducted and included any study that evaluated the effects or mechanisms of antioxidants in the healing process (in vitro, animal models, or human studies). (3) Results: Seven compounds with antioxidant activity were identified (Curcumin, N-acetyl cysteine, Chitosan, Gallic Acid, Edaravone, Crocin, Safranal, and Quercetin) and 46 studies reporting the effects on the healing process of these antioxidants compounds were included. (4) Conclusions: These results highlight that numerous novel investigations are being conducted to develop more efficient systems for wound healing activity. The application of antioxidants is useful against oxidative damage and accelerates wound healing. Designing biomaterials that can scavenge excess reactive oxygen species requires new technologies and further research, especially human studies.
REVIEW | doi:10.20944/preprints202106.0653.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: COVID-19 therapy, oxidant, antioxidant, nitric oxide (NO), thrombosis
Online: 28 June 2021 (13:49:50 CEST)
Patients with underlying health conditions are at risk for a poor outcome from Coronavirus disease 2019 (COVID-19). Using machine reasoning by the sci.AI system, we investigated the pathobiochemistry of this observation to generate therapeutic guidelines. Facts were extracted and linked from publications available in nlm.nih.gov and Europe PMC to form the dataset which was validated by medical experts. Previously we described how preexisting chronic inflammation renders the acute inflammatory response to Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) excessive translating the SARS-CoV-2 infection into the clinical COVID-19 syndrome. Herein we focus on therapeutic interventions that mitigate the immune response. In essence, from bench to bedside, as depicted in the Graphical Abstract, the clinical management of COVID-19 should aim at: A. Control of excessive oxidant production. B. Neutralization of excessive oxidants. C. Upregulation of nitric oxide (NO) production.
Subject: Chemistry, Analytical Chemistry Keywords: Fullerene; Endofullerene; Aqueous Fullerene Dispersion; Antioxidant Potential; Kinetic Chemiluminometry
Online: 26 May 2021 (14:19:39 CEST)
The antioxidant potential (capacity and activity) of aqueous fullerene dispersions (AFD) of non-functionalized C60, C70, and Gd@C82 endofullerene (in micromolar concentration range) was estimated based on chemiluminescence measurements of the model of luminol and generation of organic radicals by 2,2’-azobis(2-amidinopropane) dihydrochloride (ABAP). The antioxidant capacity was estimated by the TRAP method, from the concentration of half-suppression, and from the suppression area in the initial period. All three approaches agree and show that the antioxidant capacity of AFDs increased in the row Gd@C82 < C70 < C60. Mathematical modeling of the long-term kinetics data was used for antioxidant activity estimation. The effect of C60 and C70 is found to be quenching of the excited product of luminol with ABAP-generated radical and not an actual antioxidant effect; quenching constants differ insignificantly. Apart from quenching with a similar constant, the AFD of Gd@C82 exhibits actual antioxidant action. The antioxidant activity in Gd@C82 is 300-fold higher than quenching constants.
REVIEW | doi:10.20944/preprints202102.0592.v1
Subject: Chemistry, Analytical Chemistry Keywords: gastrointestinal diseases; nutraceutical; natural anti-inflammatory; natural antioxidant; watercress
Online: 25 February 2021 (17:03:03 CET)
The incidence of gastrointestinal diseases (cancer in particular) has increased progressively with considerable morbidity, mortality, and a high economic impact on the healthcare system. Dietary intake of natural bioactive phytochemicals showed to have cancer-preventing and therapeutic effects. This includes the cruciferous vegetable derivative phenethyl isothiocyanate (PEITC), a bioactive compound from watercress. PEITC antioxidant, anti-inflammatory and anti-cancer properties are of particular importance. This review summarizes the current knowledge on the role of PEITC as a potential natural nutraceutical or an adjuvant against oxidative/inflammatory-related disorders in the gastrointestinal tract. We also discuss the safe and recommended dose of PEITC. Besides, we establish a framework to guide the research and development of sustainable methodologies for obtaining and stabilizing this natural nutraceutical for industrial use. This is a topic that still needs more scientific development, but with the potential to lead to a viable strategy in the prevention of cancer and other associated diseases of the gastrointestinal tract.
ARTICLE | doi:10.20944/preprints202011.0586.v1
Subject: Chemistry, Analytical Chemistry Keywords: chemical composition; antioxidant; Citrus; essential oils; Principal Component Analysis.
Online: 23 November 2020 (14:19:03 CET)
Citrus essential oils (EOs) have various bioactivities like antioxidants, with many applications. Antioxidant activities depend on the chemical compositions of the EOs, which are affected by climate, soil, and geographical region. Thus, investigations on chemical compositions and antioxidant activities of Citrus EOs in different countries are valuable. In this study, we distilled EOs from peels of Indonesian-grown Citrus, including C. nobilis, C. limon, C. aurantifolia, C. amblycarpa, and Citrus spp.Chemical compositions of EOs were analyzed using Gas Chromatography-Mass Spectrometer (GC-MS), whereas the antioxidant activities were determined by employing 2,2-diphenyl-2-picrylhydrazyl (DPPH) method. Furthermore, principal component analysis (PCA) was applied to elucidate the main contributing compounds for antioxidant activity. The results show that all EOs possess unique chemical characteristics, with limonene as the majority constituent. For antioxidant activities, C. limon and C. amblycarpa EOs are the two strongest, IC50 values below 7.00 μL/mL. PCA approach suggests that -terpinene mainly contributes to the high antioxidant activities of C. limon and C. amblycarpa. Moreover, o-cymene, thymol, p-cymene, and α-pharnesene may also be responsible for the antioxidant activity of C. limon EO. These results are valuable information for the applications of Citrus EOs as antioxidant sources.
ARTICLE | doi:10.20944/preprints202008.0130.v1
Subject: Medicine & Pharmacology, Other Keywords: antioxidant; C2C12 cell; Jakyakgamcho-tang; muscle atrophy; oxidative stress
Online: 5 August 2020 (10:43:24 CEST)
Oxidative stress is a major contributor to muscle aging and loss of muscle tissue. Jakyakgamcho-tang has been used in traditional Eastern medicine to treat muscle pain. Here, we compared various solvent-based Jakyakgamcho-tang extracts in terms of their effects against hydrogen peroxide-induced oxidative stress in murine C2C12 skeletal muscle cells. Total phenolic content and total flavonoid content in 30% ethanol extracts of Jakyakgamcho-tang were higher than those of water extracts of Jakyakgamcho-tang. Ethanol extracts of Jakyakgamcho-tang had stronger antioxidant and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid and 2,2´-diphenyl-1-picrylhydrazyl-scavenging activity than water extracts of Jakyakgamcho-tang. The ethanol extract of Jakyakgamcho-tang inhibited peroxide-induced cell viability and intracellular reactive oxygen species generation more effectively than the water extract of Jakyakgamcho-tang in a dose-dependent manner. These results suggest that the ethanol extract of Jakyakgamcho-tang is relatively more efficacious at protecting against oxidative stress-induced muscle cell death because it prevents reactive oxygen species generation in C2C12 cells. Moreover, the current study indicated that the effective dose of the ethanol extract of Jakyakgamcho-tang required to alleviate muscle pain might be lower than that required for Jakyakgamcho-tang.
REVIEW | doi:10.20944/preprints202008.0119.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: astaxanthin; cardiovascular disease; atherosclerosis; inflammation; oxidative stress; carotenoids; antioxidant
Online: 5 August 2020 (09:53:14 CEST)
Cardiovascular disease is the most common cause of death. Oxidative stress and inflammation are pathophysiological processes involved in the development of cardiovascular diseases, so anti-inflammatory and antioxidant agents that modulate redox balance have become the targets of research to evaluate their molecular mechanisms and therapeutic properties. Astaxanthin, a carotenoid of the xanthophyll group, has potent antioxidant effects due to its molecular structure and its arrangement in the plasma membrane, factors that favor the neutralization of reactive oxygen and nitrogen species. This carotenoid also stands out for its anti-inflammatory activity, possibly interrelated with its antioxidant effect, as well as for its modulation of lipid and glucose metabolism. Considering the potential positive effects of astaxanthin on cardiovascular health evidenced by preclinical and clinical studies, this paper describes the molecular and cellular mechanisms related to the antioxidant and anti-inflammatory properties of this carotenoid in cardiovascular diseases, especially atherosclerosis.
Subject: Life Sciences, Cell & Developmental Biology Keywords: Nigella sativa; Carica papaya; Boswellia sacra; Antioxidant and Haematology
Online: 3 August 2020 (08:48:27 CEST)
Nigella sativa, Carica papaya and Boswellia sacra are medicinal plants in the commonly used in folkloric medicine due to the presence of its immense therapeutic properties. Fifty (50) female albino mice weighing between 15-22g were divided into five groups of 10 mice each. Animal in group 1 served as control group and were administered distilled water while animal in group 2 were given 2ml of cisplatin (orally). Animal in group 3-5 were given orally; 100 mg/kg (low dose), 200 mg/kg (medium dose) and 400 mg/kg (high dose) of triherbal preparation. The feeding regimens lasted for 28 days. After 28 days, mammary gland and blood samples were collected for haematological and antioxidant analysis. The triherbal formula decreased the GSH and MDA levels of mice treated with 100 mg/kg and 400 mg/kg doses compare to control. The measurement of total protein content, SOD and CAT increased in treated animals compared to control. However, RBC (Red Blood Cell) counts significantly decreased in the low, medium and high dose groups (0.95±0.08, 6.57±0.08 and 3.55±0.55 x 106 cells/mm3 respectively) compared to control (7.34±0.40) at P<0.05. Also, significant decreases (P<0.05) in the level of the total WBC (White Blood Cell) count, platelet count, PCV (Packed Cell Volume) and Hb (haemoglobin) concentration were observed. The decreases were dose dependent. The MCH (Mean Corpuscular Haemoglobin) and MCHC (Mean Corpuscular Haemoglobin Concentration) except MCV (Mean Corpuscular Volume) significantly decreased in treated group only. The triherbal formulation exhibited significant antioxidant activities showing increased levels of SOD, CAT and Protein content due to activation of the enzyme involve in detoxification of free radicals and decreased in the level of GSH and MDA due to accumulation of peroxides and H2O2. Also, decreased in haematological parameters due to the presence of phytochemicals such as phenol, resins, saponins, sterols, tannis and terpenes in the triherbal formula. Therefore, it has potential to induce haematotoxicity hence consumption of high concentrations should be discouraged.
Subject: Life Sciences, Molecular Biology Keywords: icariin; nicotine; sperm density; testosterone; antioxidant enzyme; male mice
Online: 14 October 2019 (09:58:40 CEST)
Nicotine is a pharmacologically active component of tobacco which adversely affects the male reproductive system and fertility and Icariin (ICA) is the main active ingredient of Epimedium herba which has been used to treat several male reproductive problems. This study was aimed at investigating the protective or ameliorative effect of ICA against reproductive toxicity induced by intraperitoneal injection of nicotine in mice. Forty male mice were randomly divided into 4 groups: control, nicotine (0.75 mg/kg intraperitoneally), icariin (ICA, 75 mg/kg), and icariin plus nicotine (ICA + nicotine) group. After 35 days of treatment, the mice were weighed, sacrificed, and their reproductive organs were collected and examined for further studies. In the nicotine-treated group, epididymal sperm density and serum testosterone concentrations significantly decreased relative to the control group. Nicotine also caused oxidative damage as shown by significant reduction in the activities of antioxidant enzymes and an elevation in Malondialdehyde (MDA) levels. Icariin on the other hand, improved the reduction in sperm characteristics, hormone levels, and activities of antioxidant enzymes alterations observed in the nicotine treated mice. These findings indicate that the nicotine-induced reproductive toxicity and oxidative damages on male reproductive tissues can be effectively attenuated by icariin.
ARTICLE | doi:10.20944/preprints201908.0293.v1
Subject: Chemistry, Organic Chemistry Keywords: Citrus aurantifolia; Citrus hystrix; Citrus microcarpa; phytochemical; antioxidant properties
Online: 28 August 2019 (11:16:06 CEST)
Leaves of Citrus aurantifolia, Citrus hystrix and Citrus microcarpa collected from Mersing, Johor were selected for this research. The extraction of these samples were carried out using three different polarities of solvents (hexane, ethyl acetate, and methanol). Phytochemical screening were done with various test for each of crude extracts. The results showed that C. aurantifolia gave positive result for alkaloids, saponins, reducing sugar and carbohydrates in hexane and ethyl acetate extracts. In contrast to C. hystrix where the presence of alkaloids, steroids, reducing sugar and carbohydrates were proven in all crude extracts. Lastly, C. microcarpa showed positive result for alkaloids, triterpenoids, saponins, flavonoids, reducing sugar, carbohydrates, phenolic content, glycosides and tannins for hexane and ethyl acetate crude extracts. Through antioxidant assays measured at wavelength 234 nm, C. aurantifoliaa has the highest AOA which was 10. The scavenging effect on DPPH radical was done at the wavelength of 517 nm and C. microcarpa has the highest percentage of scavenging effect with 96.41%. Next, the non-enzymatic antioxidant assays on the determination of α-tocopherol and carotenoids showed that C. hystrix has the highest concentration of α-tocopherol (2.30 ± 0.026), while C. microcarpa has the highest concentration of carotenoids (18.40 ± 2.83).
ARTICLE | doi:10.20944/preprints201906.0308.v1
Subject: Life Sciences, Biochemistry Keywords: chrysanthemum; HPLC; phenolic compounds; principal component analysis; antioxidant capacity
Online: 30 June 2019 (08:55:38 CEST)
This study investigated the phenolic compounds of 15 Chrysanthemum morifolium Ramat cv. ‘Hangbaiju’, including 6 ‘Duoju’ and 9 ‘Taiju’ using high performance liquid chromatography. The antioxidant activities of these ‘Hangbaiju’ were estimated by DPPH, ABTS and FPAR assays. Results showed that a total of 14 phenolic compounds were detected in these flowers, including 3 mono-caffeoylquinic acids, 3 di-caffeoylquinic acids, 1 phenolic acid and 7 flavonoids. ‘Duoju’ and ‘Taiju’ possessed different concentration of phenolic compounds, and ‘Taiju’ exhibited higher caffeoylquinic acids and stronger antioxidant activities than ‘Duoju’. Caffeoylquinic acids showed a strong correlation with the antioxidant activities of the samples. Principal component analysis revealed an obvious separation between ‘Duoju’ and ‘Taiju’ using phenolic compounds as variables. Apigenin-7-O-glucoside, 3,5-di-O-caffeoylquinic acid, luteolin and acacetin were found to be the key phenolic compounds to differentiate ‘Duoju’ from ‘Taiju’.
ARTICLE | doi:10.20944/preprints201901.0143.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: acidity; alkalinity; antioxidant defense; methylglyoxal; phytotoxicity; reactive oxygen species
Online: 15 January 2019 (07:37:11 CET)
Soil pH, either low (acidity) or high (alkalinity) is one of the major constraints that affect many biochemical and biological processes within the cell. The present study was carried out to understand the oxidative damage and antioxidant defense in wheat (Triticum aestivum L. cv. BARI Gom-25) grown under different pH regimes. Eight-day-old seedlings were exposed to growing media with different pH levels (4.0, 5.5, 7.0 and 8.5). Seedlings grown in pH 4.0 and in pH 8.5 showed reductions in biomass, water, and chlorophyll contents; whereas plants grown at pH 7.0 (neutral) exhibited better performance. Extremely acidic (pH 4.0) and/or strongly alkaline (pH 8.5)-stress also increased oxidative damages in wheat by excess reactive oxygen species (ROS) generation and methylglyoxal (MG) production, which increased lipid peroxidation and disrupted the redox state. In contrary, the lowest oxidative damage was observed at neutral condition followed by strong acidic condition (pH 5.5), which was attributed mainly due to better performance of the antioxidant defense and glyoxalase systems. Interestingly, seedlings grown at pH 5.5 showed a significant increase in morphophysiological attributes compared with extreme acidic (pH 4.0)- and strong alkaline (pH 8.5)-stress treatments, which indicates the tolerance of wheat to the acidic condition.
ARTICLE | doi:10.20944/preprints201811.0015.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: metabolic syndrome; multicomponent functional foods; antioxidant bioactive ingredients; polyphenols
Online: 2 November 2018 (05:06:26 CET)
The ANTIATERO-ALIM study was a randomized, parallel design nutritional trial testing functional food (FF) diets against the usual diet recommended in the metabolic syndrome. Functional meals included balsamic vinegar from apples and honey and grape juice enriched with polyphenols from seeds of red grapes. 300 patients with metabolic syndrome were randomized into 4 groups: gr.1: FF + Ω-3 supplements, gr.2: FF, gr.3: Ω-3 supplements, gr.4: control. IRHOMA insulin resistance, plasma lipids and oxidative stress were assessed at inclusion and at 6 months. After 6 months there was a very significant decrease of oxidative stress in group 3, followed by a significant decrease in groups 1 and 2.
COMMUNICATION | doi:10.20944/preprints201810.0408.v1
Subject: Chemistry, Other Keywords: Salvia pachyphylla; plant extracts; antioxidant; antimicrobial; antiproliferative; enzyme inhibitory
Online: 18 October 2018 (09:56:26 CEST)
The antioxidant, antimicrobial, antiproliferative, and enzyme inhibitory properties of five extracts from aerial parts of Salvia pachyphylla were examined to assess the prospective of this plant as a source of natural products with therapeutic potential. Those properties were analyzed performing a set of standard assays. The extract obtained with dichloromethane showed the most variety of components, as yielded promising results in all completed assays. Furthermore, the extract obtained with ethyl acetate exhibited that greatest antioxidant activity as well as the best xanthine oxidase inhibitory activity. Remarkably, both extracts obtained with n-hexane or dichloromethane revealed significant antimicrobial activity against the Gram-positive bacteria; also, they showed greater antiproliferative activity against three representative cell lines of the most common types of cancers in women worldwide, and against a cell line that exemplifies cancers that typically develop drug resistance. Despite that other extracts were less active, such as the methanolic or aqueous, their results are promising for the isolation and identification of novel bioactive molecules.
ARTICLE | doi:10.20944/preprints201809.0508.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Moringa oleifera L., antioxidant activity, cell culture, irritant potential
Online: 26 September 2018 (13:16:14 CEST)
Extracts obtained from leaves of Moringa tree (Moringa oleifera) are a rich source of many bioactive compounds: flavonoids, phenolic acids or carotenoids. It also contains such components as, vitamins (A, C, niacin, pantothenic acid), alkaloids, tannins or saponins. Extracts and plant substances derived from the leaves of Moringa oleifera L. have a strong antioxidant, toning and anti-inflammatory effect. The work attempts to obtain a multifunctional plant extract derived from Moringa tree leaves. Obtained extracts was analyzed for their biochemical and physicochemical properties. The obtained results indicate on a strong antioxidative potential of the tested extracts. The further step was an attempt to apply the extracts in the model body wash cosmetic. The biological activity of extracts and model cosmetic formulation were assayed by in vitro analysis on two human cell lines: keratinocytes (HaCat,) and fibroblasts (BJ). The results showed that the tested extracts may affect on increasing of cell proliferation and reduce oxidative stress in cells. The addition of the tested extracts to the model cosmetic formulation, were contributed to the reduction of their ability to irritate the skin and improve the safety of use of the product.
ARTICLE | doi:10.20944/preprints201807.0088.v1
Subject: Chemistry, Analytical Chemistry Keywords: nutrient profiling; simulated gastrointestinal digestion; antioxidant activity; fish soup
Online: 5 July 2018 (08:51:14 CEST)
Different kinds of freshwater fish soups show a diverse range of health functions, due to their different nutritional substances and corresponding bioactivities. Crucian carp soup and snakehead soup have different dietotherapy functions, crucian carp soup is suitable for lactating women and snakehead soup is suitable for postoperative patients. In the current study, the changes of nutrient profiles in the different fish soups, such as chemical composition, free amino acids, mineral and fatty acid contents, were investigated. The antioxidant activities of the fish soups were evaluated by using the DPPH radical scavenging activity, the ferrous ion chelating activity, the hydroxyl radical-scavenging activity and the reducing power effect. In order to learn the theoretical basis of the potential role fish soup plays in diet therapy functions after being digested by the human body, the nutrient profiling and bioactivities of the fish soup samples after simulated gastrointestinal digestion were also explored. The intensive profiles of nutritional composition and antioxidant activities of these two kinds of fish soups were expected to partly provide the theoretical basis of therapeutic effects.
ARTICLE | doi:10.20944/preprints201806.0130.v1
Subject: Materials Science, Biomaterials Keywords: wound healing; catechol; conjugated; antioxidant; antiinflammatory; bioadhesion; UV shielding
Online: 8 June 2018 (12:28:07 CEST)
The effective treatment for chronic wounds constitute one of the most common worldwide health care problem due to the presence of high levels of proteases, free radicals and exudates in the wound, which constantly activate the inflammatory system avoiding the tissue regeneration. In this study, we describe a multifunctional bioactive and resorbable membrane with in-built antioxidant agent for the continuous quenching of free radicals as well as to control inflammatory response helping to promote the wound healing process. To reach that goal synthesized statistical copolymers of N-vinylcaprolactam (V) and 2-hydroxyethyl methacrylate (H) have been conjugated with catechol bearing hydrocaffeic acid (HCA) molecules. The natural polyphenol (catechol) is the key molecule responsible for the mechanism of adhesion of mussels, and provides the functionalized polymer conjugate a continuous antioxidant response, antiinflammatory effect, UV screen and bioadhesion in the moist environment of the human body, all of them key features in the wound healing process. Therefore, these novel mussel-inspired materials have an enormous potential of application and can act very positively, favoring and promoting the healing effect in chronic wounds.
ARTICLE | doi:10.20944/preprints201801.0190.v1
Subject: Keywords: apricot; total phenolic; antioxidant activity; organic growing; Hasanbey; Alyanak
Online: 20 January 2018 (14:15:22 CET)
This research was carried out to see the effects of organic farming and determine the yield and some pomological characteristics of apricots in Isparta, Turkey. Isparta province which is located in the west Mediterranean part of Turkey has also gained importance in terms of especially organic apricot production. Two apricot varieties (Hasanbey, Alyanak) were grown with organic farming practices in this study. These two varieties are table types apricot varieties commonly grown in Turkey’s one of the world's major producers. In this research, pomological characteristics as fruit size (fruit height, fruit width, fruit weight, fruit length), fruit firmness, pH, total soluble solid (TSS) content, titrable acidity (TA) and yield values were determined. Total phenolic and antioxidant activity were also determined. Hasanbey cultivar had higher yield value (66.21 kg/tree) than Alyanak (45.71 kg/tree) cultivar. At the same time the total phenolic content of Hasanbey (307.12 mg GAE/100g) variety was determined higher than Alyanak (175.91 mg GAE/100g). Antioxidant activity of Alyanak and Hasanbey were determined as 32.86 mg/ml IC50 and 17.37 mg/ml IC50 respectively. In terms of observed characteristics, Hasanbey cultivar was found to be prominent in Isparta. It can also been recommended for other places similar to Isparta ecological conditions (highland climate).
ARTICLE | doi:10.20944/preprints202111.0577.v1
Subject: Life Sciences, Other 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.
REVIEW | doi:10.20944/preprints202109.0449.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: glutathione; glutamate; psychosis; schizophrenia; redox; antioxidant; oxidative stress; myelin; spectroscopy
Online: 27 September 2021 (12:47:39 CEST)
Schizophrenia continues to be an illness with poor outcome. Most mechanistic changes occur many years before the first episode of schizophrenia; these are not reversible after the illness onset. A developmental mechanism that is still modifiable in adult life may center on intracortical glutathione (GSH). A large body of pre-clinical data has suggested the possibility of notable GSH-deficit in a subgroup of patients with schizophrenia. Nevertheless, studies of intracortical GSH are not conclusive in this regard. In this review, we highlight the recent ultra-high field magnetic resonance spectroscopic studies linking GSH to critical outcome measures across various stages of schizophrenia. We discuss the methodological steps required to conclusively establish or refute the persistence of GSH-deficit subtype and clarify the role of the central antioxidant system in disrupting the brain structure and connectivity in the early stages of schizophrenia. We propose in-vivo GSH quantification for patient selection in forthcoming antioxidant trials in psychosis. This review offers directions for a promising non-dopaminergic early intervention approach in schizophrenia.
REVIEW | doi:10.20944/preprints202108.0558.v1
Subject: Materials Science, Polymers & Plastics Keywords: chitosan; chitin; biological activit; drug delivery; antioxidant; antimicrobial; biocatalysis; nanoparticles
Online: 31 August 2021 (11:07:28 CEST)
Chitosan arouses large interest due to its properties and possible applications. Every year the number of publications and patents based on this polymer increases. Chitosan exhibits poor solubility in neutral and basic media limiting its use in such conditions. Another serious obstacle is directly related to its natural origin. Chitosan is not a single polymer with a defined structure but a family of molecules with differences in their composition, size, and monomer distribution. These properties have a fundamental effect on the biological and technological performance of the polymer. Moreover, some of the biological properties claimed are discrete. In this review, we discuss how chitosan chemistry can solve the problems related to its poor solubility and can boost the polymer properties. We focus on some of the main biological properties of chitosan and the relationship with the physicochemical properties of the polymer. Then, we visit two polymer applications related to green processes: the use of chitosan in the green synthesis of metallic na-noparticles and its use as support in biocatalyst. Finally, we briefly describe how making use of the technological properties of chitosan it is possible to develop a variety of systems for drug delivery
Subject: Life Sciences, Other Keywords: Silage supplement; Pomegranate residues; avocado residues; poultry; antioxidant,; meat quality
Online: 23 August 2021 (13:42:54 CEST)
In the present study pomegranate peels and avocado peels and seeds vacuum microwave extraction solid by-products were supplemented in corn silage in order to investigate the effects on meat quality and growth rate in broiler chicken. 50 broilers were divided in two groups treated with experimental or usual fed for 43 days (group A: 25 broilers fed with avocado and pomegranate by-products and group B: 25 broilers fed with corn-silage used as control). The results showed that broiler chickens fed with diet supplemented with a mixture of pomegranate avocado by-products (group A) shown significant differences in chicken leg meat quality improving in significant level the proteins and fatty acids contents in breast and leg meat respectively. More specific ω3 and ω6 fatty acids contents were three times higher than in group B. Moreover protective effect on the decomposition of polyunsaturated fatty acids induced by free radicals presented in chicken meat based on the evaluation of lipid peroxidation by measuring thiobarbituric acid reactive substances. Pomegranate peels, avocado peels and seeds by-products appeared slight reduction on meat production while it was found to improve the qualitative chicken meat characteristics. Regarding the production costs, it was calculated that the corn-silage supplementation used in this study lead to a 75% lower cost than the commercial corn-silage used for the breeding of broilers.
ARTICLE | doi:10.20944/preprints202012.0511.v1
Subject: Life Sciences, Microbiology Keywords: Antioxidant enzymes; hemibiotroph; reactive oxygen species; host-pathogen interaction; sporulation
Online: 21 December 2020 (11:23:57 CET)
Wheat blast caused by the hemibiotroph fungal pathogen Magnaporthe oryzae Triticum (MoT) pathotype, is a destructive disease of wheat in South America and Bangladesh. Generation of reactive oxygen species (ROS) is one of the defense responses in plants during the infection process by a pathogen. However, empirical evidence on regulation of ROS in wheat and other host and non-host plants towards MoT is limited. This study aimed to determine the susceptibility of some major cereals and weeds of Bangladesh and compare the antioxidant enzyme activities in host and non-host plants in response to artificial inoculation by MoT. Seedlings of wheat, maize, barley and swamp rice grass were susceptible to MoT and produced considerable number of conidia on infected leaves (host). Rice seedlings showed a resistant response in our laboratory conditions (non-host). The activities of ROS-detoxifying enzymes; catalase (CAT), ascorbate peroxidase (APX), Glutathione peroxidase (GPX), Glutathione S-transferase (GST), Peroxidase (POX) increased in all plants after inoculation by MoT with a few exceptions. Interestingly, an early and very high accumulation of CAT was observed within 24 hours of inoculation (hai) in wheat, barley, maize and swamp rice grass while H2O2 concentration was low during that time and immediately after that (24-48 hai). In contrast, an early and high accumulation of H2O2 was observed in rice at 48 hai with little CAT activity only at a late stage. The APX, GST and POD activity was also increased due to the inoculation of MoT at the early stage of infection in rice but were very high at the disease progression stage in wheat, barley, maize and swamp rice grass. GPX activity gradually decreased with the increase of time in rice. Taken together, our results suggest that a robust and late induction of most of the antioxidant enzyme activities occurs in susceptible/host plants whereas an early induction of antioxidant enzyme activities occurs in resistant/ non-host plant but with slow kinetics.
ARTICLE | doi:10.20944/preprints202012.0432.v1
Subject: Life Sciences, Biochemistry Keywords: pomegranate; antioxidant capacity; membrane vesicles; cauliflower; keratinocytes; oxidative stress; cytotoxicity
Online: 17 December 2020 (12:05:42 CET)
Pomegranate extract (PG-E) has been reported to exert a protective effect in skin due to its antioxidant activity. Ingredients rich in phenolic compounds are unstable in extract solutions and, therefore, the use of a suitable nanosystem to encapsulate this type of extract could be necessary in different biotechnological applications. Thus, we investigated the capacity of Brassica oleracea L. (cauliflower) inflorescence vesicles (CI-vesicles) to encapsulate PG-E and determined the stability and the antioxidant capacity of the system over time. In addition, the protective effect against UV radiation and heavy metals in HaCaT cells was also tested. The CI-vesicles had an entrapment efficiency around 50% and accelerated stability tests did not show significant changes in the parameters tested. The results for the HaCaT cells show the non-cytotoxicity of the CI-vesicles containing PG-E and their protection against heavy metals (lead acetate and mercuric chloride) and UV-B radiation through a reduction of oxidative stress. The reduction of the percentage of deleted mtDNA (mtDNA4977, “common deletion”) in UV-treated HaCaT cells due to the presence of CI-vesicles containing PG-E indicates the mechanism of protection. Therefore, the effects of CI-vesicles loaded with PG-E against oxidative stress support their utilization as natural cosmeceuticals to protect skin health against external damage from environmental pollution and UV radiation.
ARTICLE | doi:10.20944/preprints202008.0524.v1
Subject: Chemistry, Organic Chemistry Keywords: Isoxazolines; nitrile oxide; 1,3-dipolar cycloaddition; antibacterial activity; antioxidant activity
Online: 24 August 2020 (10:03:22 CEST)
A series of derivatives of trans-3-(2,4,6-trimethoxy phenyl)-4,5-dihydro isoxazolo-4,5-bis(aroylcarbohydrazide) and of trans-3-(2,4,6-trimethoxyphenyl)4,5-dihydroisoxazolo-4,5-bis[carbonyl-(4’phenyl)thiosemi- carbazide (9) were synthesized from trans-3-(2,4,6-trimethoxyphenyl)-4,5-dihydro-4,5-bis(hydrazenocarbonyl) Isoxazole (8). The structures of the Compounds were elucidated by elemental and spectral (IR, NMR, and MS) analysis. The compound 9 show activity against some bacterial species. Whereas, no activity was observed for compounds 10a, 10b and 10c against all bacterial species. The antioxidant activity of new compounds has been screened. Compound 9 showed higher antioxidant activity using the DPPH and ATBS method.
ARTICLE | doi:10.20944/preprints202007.0350.v1
Subject: Chemistry, Medicinal Chemistry Keywords: 3,4-DHPEA-EA; C2C12 myocytes; olive oil; antioxidant; skeletal muscle
Online: 16 July 2020 (12:56:25 CEST)
Oleuropein, glycosylated secoiridoid present in olive leaves is known to be an important antioxidant phenolic compound. We studied the antioxidant effect of low doses of oleuropein aglycone (3,4-DHPEA-EA) and oleuropein aglycone peracetylated (3,4-DHPEA-EA(P)) in murine C2C12 myocytes treated with hydrogen peroxide (H2O2). Both compounds were used at a concentration of 10 μM and were able to inhibit cell death induced by the H2O2 treatment, with 3,4-DHPEA-EA(P) being more. Under our experimental conditions, H2O2 efficiently induced the phosphorylated-active form of JNK and of its downstream target c-Jun. We demonstrated, by Western blot analysis, that 3,4-DHPEA-EA(P) was efficient in inhibiting the phospho-active form of JNK. This data suggests that the growth arrest and cell death of C2C12 proceeds via the JNK/c-Jun pathway. Moreover, we demonstrated that 3,4-DHPEA-EA(P) affects the myogenesis of C2C12 cells; because MyoD mRNA levels and the differentiation process are restored with 3,4-DHPEA-EA(P) after treatment. Overall, the results indicate that 3,4-DHPEA-EA(P) prevents ROS-mediated degenerative process in a genomic and epigenomic manner by functioning as an efficient antioxidant.
ARTICLE | doi:10.20944/preprints202007.0312.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Arbutus unedo L; biochemical assessment; antioxidant capacity; phenolic compounds; Morocco
Online: 14 July 2020 (13:41:53 CEST)
There are not many exhaustive works emphasizing the amount of genetic diversity among the strawberry tree (Arbutus unedo L.) genotypes in Morocco. This work aims to assess the biochemical composition of strawberry tree fruits, as well as to establish the variation of this composition among them. In this study, total phenols, total flavonoids, condensed and hydrolyzable tannins, total anthocyanins and free radical scavenging activity through ABTS were investigated in strawberry tree fruits. Furthermore, qualitative and quantitative analyses of individual phenolic compounds by high-performance liquid chromatography (HPLC) were carried out. Color parameters such as lightness (L*), Chroma (c*) and hue angle (h°) were also investigated. All studied variables showed highly significant differences among all samples with the exception of hydrolyzable tannins and chromatic coordinates. Total phenolics varied from 22.63 ± 1.74 to 39.06 ± 2.44 mg GAE/g dry wt, total flavonoids varied from 3.30 ± 0.60 to 8.62 ± 1.10 mg RE/g dry wt and total anthocyanins ranged between 0.12 ± 0.06 and 0.66 ± 0.15 mg cya-3-glu/100g dry wt. In addition, condensed and hydrolyzable tannins amounts were in the range of 10.41 ± 1.07 - 16.08 ± 1.50 mg TAE/g dry wt and 4.08 ± 2.43 - 6.34 ± 3.47 respectively. Moreover, the IC50 value (ABTS) ranged between 1.75 and 19.58 mg AAE/g dry wt. 17 phenolic compounds were detected in strawberry tree fruits. Gallocatechol and catechin were the most abundant phenolic compound. Matrix of correlations revealed signiﬁcant positive and negative correlations among variables particularly c*, a* and b*. Principal component analysis showed that the ﬁrst three components formed than 68% of the total inertia. The following variables gallic acid, protocatechuic, gallocatechin, gallic acid derivative, chlorogenic acid, syringic acid, ellagic acid derivative II, L* and h* were the most involved in the total variance explained. Hierarchical clustering classified samples into one main cluster, with a single branch. The results highlight a high biochemical diversity within studied strawberry genotypes, which is probably more genetically related
ARTICLE | doi:10.20944/preprints202007.0247.v1
Subject: Life Sciences, Biochemistry Keywords: 3,4-DHPEA-EA; C2C12 myocytes; olive oil; antioxidant; skeletal muscle
Online: 12 July 2020 (08:22:31 CEST)
Oleuropein, glycosylated secoiridoid present in olive leaves is known to be an important antioxidant phenolic compound. We studied the antioxidant effect of low doses of oleuropein aglycone (3,4-DHPEA-EA) and oleuropein aglycone peracetylated (3,4-DHPEA-EA(P)) in murine C2C12 myocytes treated with hydrogen peroxide (H2O2). Both compounds were used at a concentration of 10 μM and were able to inhibit cell death induced by the H2O2 treatment, with 3,4-DHPEA-EA(P) being more. Under our experimental conditions, H2O2 efficiently induced the phosphorylated-active form of JNK and of its downstream target c-Jun. We demonstrated, by Western blot analysis, that 3,4-DHPEA-EA(P) was efficient in inhibiting the phospho-active form of JNK. This data suggests that the growth arrest and cell death of C2C12 proceeds via the JNK/c-Jun pathway. Moreover, we demonstrated that 3,4-DHPEA-EA(P) affects the myogenesis of C2C12 cells; because MyoD mRNA levels and the differentiation process are restored with 3,4-DHPEA-EA(P) after treatment. Overall, the results indicate that 3,4-DHPEA-EA(P) prevents ROS-mediated degenerative process in a genomic and epigenomic manner by functioning as an efficient antioxidant.
ARTICLE | doi:10.3390/sci2020031
Subject: Keywords: Khechechuri pear; Adjara region; phenolic compounds; catechins; flavonoids; antioxidant activity
Online: 9 May 2020 (00:00:00 CEST)
An endemic pear species spreads in one region of western Georgia, Adjara, called Khechechuri. Pears are dietary source of bioactive components such as polyphenols and triterpenic acid. In addition to its gastronomic value, the aim of the article was to examine and compare phenolic compounds, flavonoids, catechins, phenolic acids, and antioxidant activities in five species of Khechechuri collected from various regions in Adjara region: Adjaristskali, Merisi, Dandalo, Shuakhevi, and Khulo. Five fruit parts, the skin, edible pulp, the whole pear (skin + pulp), juice and the pomace were analyzed and the results were compared. Our study revealed that the amount of total phenolic content found in the skin of West Georgian pear types was as much as 4650 mg/kg. Also, the pear pomace showed significant amount of total phenolic content in all species of Khechechuri. In addition, in all species of Khechechuri pears, flavonoids were found, except in the fruit juice.
ARTICLE | doi:10.20944/preprints201912.0387.v1
Subject: Chemistry, Medicinal Chemistry Keywords: 3,4-DHPEA-EA; C2C12 myocytes; olive oil; antioxidant; skeletal muscle
Online: 29 December 2019 (13:55:48 CET)
Oleuropein, glycosylated secoiridoid present in the olive leaves, is known as an important antioxidant phenolic compound. We studied the antioxidant effect of low dose of oleuropein aglycone (3,4-DHPEA-EA) and oleuropein aglycone peracetylated (3,4-DHPEA-EA(P)) in murine C2C12 myocytes treated with hydrogen peroxide (H2O2). Both compounds were used at a concentration of 10 μM and were able to inhibit cell death induced by H2O2 treatment, with 3,4-DHPEA-EA(P) being more. Under our experimental conditions H2O2 efficiently induced the phosphorylated-active form of JNK and of its downstream target c-Jun. We demonstrated, by Western blot analysis, that 3,4-DHPEA-EA(P) was efficient in inhibiting the phospho-active form of JNK. This data suggest that growth arrest and cell dead of C2C12 proceeds via the JNK/c-Jun pathway. Moreover, we demonstrated that 3,4-DHPEA-EA(P) affects myogenesis of C2C12 cells; because the MyoD mRNA levels and the differentiation process are restored after treatment with 3,4-DHPEA-EA(P). Overall, the results indicate that 3,4-DHPEA-EA(P) prevents ROS-mediated degenerative process by functioning as an efficient antioxidant.