REVIEW | doi:10.20944/preprints202203.0124.v2
Subject: Biology And Life Sciences, Plant Sciences Keywords: anthocyanins; proanthocyanidins; flavonols; flavones; flavonoid transport; flavonoid biosynthesis; flavonoid accumulation; ligandin; MATE; ABCC
Online: 28 March 2022 (17:03:39 CEST)
Flavonoids are a biochemically diverse group of specialized metabolites in plants that are derived from phenylalanine. While the biosynthesis of the flavonoid aglycone is highly conserved across species and well characterized, numerous species-specific decoration steps and their relevance remained largely unexplored. The flavonoid biosynthesis takes place at the cytosolic site of the endoplasmatic reticulum (ER), but accumulation of various flavonoids was observed in the central vacuole. A universal explanation for the subcellular transport of flavonoids has eluded researchers for decades. Current knowledge suggests that a glutathione S-transferase-like protein (ligandin) protects anthocyanins and potentially proanthocyanidin precursors during the transport to the central vacuole. ABCC transporters and to a lower extend MATE transporters sequester anthocyanins into the vacuole. Glycosides of specific proanthocyanidin precursors are sequestered through MATE transporters. A P-ATPase in the tonoplast and potentially other proteins generate the proton gradient that is required for the MATE-mediated antiport. Vesicle-mediated transport of flavonoids from the ER to the vacuole is considered as an alternative or additional route.
ARTICLE | doi:10.20944/preprints202306.1280.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Berberis vulgaris; antioxidants; phenolic acids, flavonoid glycosides, flavonoid aglycones, anti-inflammatory
Online: 19 June 2023 (04:07:26 CEST)
Berberis vulgaris L. is currently widely studied for its antioxidant and chemopreventive proper-ties, especially given the beneficial properties of its fruits in this regard. Although the bark and roots have been well known and used in traditional medicine since ancient times, little is known about the other parts of this plant. The aim of the research was to determine the antioxidant and LOX inhibitory activity effects of extracts obtained from leaves, fruits, and stems. Another aim of the work was to carry out the quantitative and qualitative analysis of phenolic acids, flavonoid aglycones, and flavonoid glycosides. Extracts were obtained with the use of ASE (accelerated solvent extraction). The total content of polyphenols was determined and was found to vary de-pending on the organ, with the highest amount of polyphenols found in the leaves extract. The free radical scavenging activity of the extracts was determined spectrophotometrically in relation to the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, with results ranging from 63.88 mgTE/g for leaves to 65.25 mgTE/g for the stem. Antioxidant activity was also assessed using the ABTS test. The lowest value was recorded for the barberry fruit (117.93 mg TE/g) and the highest level was found for the barberry leaves (140.49 mgTE/g). The oxygen radical absorption capacity test (ORAC) showed the lowest value for the stem (167.70 mgTE/g) and the highest level for the leaves (267.81 mgTE/g). The range of percentage inhibition of LOX was determined as well. The percentage inhibition of the enzyme was positively correlated with the sum of flavonoids, TPC, TFC, and the content of selected flavonoids. For the first time, phenolic acids, flavonoid agly-cones, and flavonoid glycosides were determined qualitatively and quantitatively in individual parts of Berberis vulgaris L. The content of phenolic acids, flavonoid aglycones, and flavonoid glycosides was determined with the LC-MS/MS method. For the first time, the following phenol-ic acids were quantitatively and qualitatively identified in individual parts of Berberis vulgaris: 3-caffeoylquinic acid, protocatechuic acid, 5-caffeoylquinic acid, flavonoid glycosides: eleuthero-side E, rutin, isoquercitin, luteoloside, nar-cissoside, naringenin-7-glucoside, isorhamnetin-3-glucoside, afzeline, and quercitrin. Flavonoid aglycones: catechin, luteolin, and eriodictyol were determined qualitatively and quantitatively for the first time as well.
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: Astragalus aitosensis; flavonoid; glycoside
Online: 29 March 2019 (09:13:02 CET)
Astragalus is a very interesting plant genus well-known for content of flavonoids, triterpenes and polysaccharides. Its secondary metabolites are described as biologically active compounds showing a number of activities, like immunomodulating, antibacterial, antiviral and hepatoprotective. This inspired us to analyze the Bulgarian endemic A. aitosensis (Ivanisch.) to obtain deeper information about its phenolic components. We used extensive chromatographic separation of A. aitosensis extract to obtain seven phenolic compounds (1–7), which were identified using combined LC-MS and NMR spectral studies. The 1D and 2D NMR analysis and HR-MS allowed us to resolve the structures of known compounds 5–7 as isorhamnetin-3-O-robinobioside, isorhamnetin-3-O-(2,6-di-O-α-rhamno-pyranosyl-β-galactopyranoside), and alangiflavoside, respectively, and further comparison of these spectral data with available literature helped us with structural analysis of newly described flavonoid glycosides 1–4. These were described in plant source for the first time.
ARTICLE | doi:10.20944/preprints202310.1261.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: hesperidin; α-glucosidase; antidiabetic; flavonoid; orange
Online: 19 October 2023 (10:07:53 CEST)
The α-glucosidase inhibitor is of interest to researchers due to its association with type-II diabetes treatment by suppressing postprandial hyperglycemia. Hesperidin is a major flavonoid in orange fruit with diverse biological properties. This paper evaluates the effects of hesperidin on α-glucosidase through inhibitory kinetics, fluorescence quenching, and molecular docking methods for the first time. The inhibition kinetic analysis showed that hesperidin reversibly inhibited the α-glucosidase activity with an IC50 value of 18.52 M and the inhibition was performed in an uncompetitive type. Fluorescence quenching studies indicated that the intrinsic fluorescence of α-glucosidase was quenched via a static quenching process and only one binding site was present between hesperidin and α-glucosidase. The interaction between them was spontaneous and mainly driven by hydrogen bonds as well as hydrophobic forces. Furthermore, molecular docking results suggested that hesperidin might bond to the entrance or outlet part of the active site of α-glucosidase through a network of five hydrogen bonds formed between hesperidin and the four amino acid residues (Trp709, Arg422, Asn424, and Arg467) of ?-glucosidase and hydrophobic effects. These results provide new insights into the inhibitory mechanisms of hesperidin on α-glucosidase, supporting the potential application of hesperidin-rich orange product as a hypoglycemic functional food.
ARTICLE | doi:10.20944/preprints202305.1294.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: mulberry leaf; frost; metabolomics; DNJ alkaloid; flavonoid
Online: 18 May 2023 (08:01:00 CEST)
Mulberry leaves are a classic herb commonly used in traditional Chinese medicine, and experience since ancient times has shown that leaves collected after frost have better medicinal properties. However, the characteristics of the changes of critical metabolic components in mulberry leaves, especially Morus nigra L., are still unknown. To further study the influence of harvesting time on the dynamic changes of metabolites, especially DNJ compounds and flavonoids, in mulberry leaves after frost. We used metabolomics technology to select 100+ metabolites as indexes to reflect the dynamic changes of metabolites in mulberry leaves comprehensively. The results showed significant differences in the effects of defrosting on the accumulation of metabolites in the leaves of Morus nigra L. and Morus alba L. The content of DNJ in the leaves of Morus nigra L. showed a decreasing trend after the frost, while flavonoids reached the peak of the second frost. For Morus alba L, DNJ showed an increasing trend after frost, especially reaching its peak one day after the second frost. Flavonoids mainly peak in the week before the frost. In addition, by analyzing the influence of picking time on metabolite accumulation in two mulberry leaves, it was concluded that higher DNJ alkaloids and flavonoids would be obtained in mulberry leaves collected in the morning. This study also provides scientific guidance for the optimum harvesting time of mulberry leaves.
REVIEW | doi:10.20944/preprints202306.0663.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Flavonoid; non-canonical inflammasome; anti-inflammatory; inflammatory disease; nutraceutical
Online: 9 June 2023 (04:12:04 CEST)
Inflammasomes are multiprotein complexes that activate inflammatory responses by inducing pyroptosis and secretion of pro-inflammatory cytokines. Along with many previous studies on inflammatory responses and diseases induced by canonical inflammasomes, an increasing number of studies have demonstrated that non-canonical inflammasomes, such as mouse caspase-11 and human caspase-4 inflammasomes, are emerging key players in inflammatory responses and various diseases. Flavonoids are natural bioactive compounds found in plants, fruits, vegetables, and teas and have pharmacological properties in a wide range of human diseases. Many studies have successfully demonstrated that flavonoids play an anti-inflammatory role and ameliorate many inflammatory diseases by inhibiting canonical inflammasomes. Others have demonstrated the anti-inflammatory roles of flavonoids in inflammatory responses and various diseases, with a new mechanism by which flavonoids inhibit non-canonical inflammasomes. This review discusses recent studies that have investigated the anti-inflammatory roles and pharmacological properties of flavonoids in inflammatory responses and diseases induced by non-canonical inflammasomes and further provides insight into developing flavonoid-based therapeutics as potential nutraceuticals against human inflammatory diseases.
REVIEW | doi:10.20944/preprints202312.0265.v1
Subject: Dietetics And Nutrition, Medicine And Pharmacology Keywords: Antidiabetic; GLP-1; Ipomoea batatas L. flavonoid; pharmacology
Online: 6 December 2023 (05:15:09 CET)
Ipomoea batatas L. (IBL) has gained significant popularity as a complementary therapy or herbal medicine in the treatment of anti-diabetes. The objective of this review is to examine the mechanism of action of flavonoid compounds found in IBL that can activate GLP-1 as an anti-diabetic agent. The review article refers to PRISMA guidelines. The literature search was conducted using electronic databases such as Crossref, Pubmed, Scopus, and Science Direct. The search query was based on specific keywords, including Ipomoea batatas OR sweet potato AND anti-diabetic OR hypoglycemic. A total of 1055 articles were found, but only 32 articles were selected for further review based on inclusion and exclusion criteria. IBL contains various compounds, including phenolic acid, flavonols, flavanols, flavones, and anthocyanins, which exhibit activity against anti-diabetes. Flavonols, flavonols, and flavones belong to a group of flavonoids that possess the ability to form complexes with AlCl3 and Ca2+. Retention of Ca2+ within intracellular L cells, resulting in the release of GLP-1. Flavonols, flavones, and flavone groups have been found to strongly interact with DPP-IV, which inhibits the degradation of GLP-1. This mechanism effectively prolongs the half-life of GLP-1 in the systemic system, thereby contributing to the anti-diabetic activity of IBL
ARTICLE | doi:10.20944/preprints202304.1235.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Genomic prediction; flavonoid pigmentation; Sorghum bicolor; prediction accuracy; marker-assisted selection
Online: 29 April 2023 (10:11:10 CEST)
Marker-assisted selection (MAS) and genomic selection (GS) have been used to select individuals with desirable traits. MAS used a few markers associated with a specific trait to select individuals with desirable traits, which are determined after a Genome-wide association studies (GWAS). On the contrary, GS uses a large number of markers distributed across the genome to predict the genomic breeding values for a further selection of the individuals. In general, MAS has shown a high prediction accuracy but is not suitable for traits that are controlled for multiple genes, and has another constraint, it is required the phenotypic data; on the contrary, GS has not shown the highest prediction accuracy as MAS but it takes into account the effect of multiple genes controlling a target trait and it can be used without phenotypic data. Including GWAS-selected markers in GS can enhance the reduced prediction accuracy that GS shows in comparison with MAS. Thus, the objective of this study was to compare the prediction accuracy of MAS, and some models of genomic prediction (gBLUP, gBLUP including GWAs-selected markers, and some Bayesian models such as Bayes A, Bayes B, Bayes LASSO and Bayesian Ridge Regression) with GWAS-selected markers incorporated in gBLUP in order to confirm if the incorporation of GWAS in GS increases the prediction accuracy of GS. As a model for this study, it was used data from Sorghum which has shown population structure, to evaluate if the incorporation of GWAs-selected markers into GS improves prediciton accuracy. It was used a sample of 6000 SNPs out of the 265.487 reported in the study conducted by Morris et al (2013), and also it was considered some parameters that affect the efficiency of the selection such as the size of the training population, the heritability, and the number of QTNs. The GWAS-selected SNPs were identified after using the model BLINK. The results showed that the incorporation of GWAS-selected markers enhanced the performance of the genomic selection with similar prediction accuracy as MAS, the number of QTNs and size of the training population affected the accuracy, with higher accuracy with a bigger size of the training population and with a lower number of QTNs, but it seems that the heritability does not have any impact in the model where GWAS-selected SNPs were included in gBLUP.
ARTICLE | doi:10.20944/preprints202304.0456.v1
Subject: Biology And Life Sciences, Horticulture Keywords: Loropetalum chinense var. rubrum; flavonoid biosynthesis; anthocyanins; flower coloring; metabolomic; transcriptomic.
Online: 18 April 2023 (02:28:00 CEST)
The Loropetalum chinense and Loropetalum chinense var. rubrum are typical and traditional ornamental and Chinese herbal medicine in Asia. However, more information is needed on the mechanisms underlying its flower coloring. Here, we profiled the flavonoid metabolome, full-length sequencing, and transcriptome analysis to investigate the flavonoid biosynthesis and global transcriptome changes among different petal coloring cultivars of L. chinense and L. chinense var. rubrum. The total anthocyanins and phenotypic of the petal were highly consistent with the petal color. Moreover, a total of 207 flavonoid components were identified. Of these, 12 flavonoid components were considered significantly different expression compounds among the four samples. Meanwhile, the first reference full-length transcriptome of L. chinense var. rubrum was being built, which had 171,783 high-quality non-redundant transcripts with correcting with next-generation sequencing (NGS). Among them, 52,851 transcripts were annotated in the seven database of NR, KOG, GO, NT, Pfam, Swiss-Port and KEGG. Combined with NGS analysis, the DETs involved in flavonoids and anthocyanins contributed greatest to the flower-coloring. Additionally, the different expressed of eight LcDFRs and four LcANS genes were positively correlated with flavonoid biosynthesis, and the four LcBZ1 and one Lc3Mat1 were positively correlated with the content of seven anthocyanins revealed by coupling with metabolomics and transcriptomics analysis. Together these results were used to mine candidate genes by analyzing flower coloring changes in a comprehensive metabolic and transcriptomic level in L. chinense and L. chinense var. rubrum.
ARTICLE | doi:10.20944/preprints202009.0341.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: flavonoid; polyphenols; orange extract; performance; endurance; aerobic; anaerobic; nutrigenomic; sport nutrition
Online: 16 September 2020 (03:10:12 CEST)
2S-hesperidin is a flavanone (flavonoid) found in high concentrations in citrus fruits. It has an antioxidant and anti-inflammatory effect, improving performance in animals. This study investigated the effects of chronic intake of an orange extract (2S-hesperidin) or placebo on aerobic-anaerobic and metabolic performance markers in amateur cyclists. A double-blind, randomized, placebo-controlled trial was carried out between late September and December 2018. Forty amateur cyclists were randomized into two groups: one taking 500mg/day 2S-hesperidin and other taking 500 mg/day placebo (microcellulose) for 8 weeks. All participants completed the study. Performance and metabolic aerobic-anaerobic markers were measured using incremental and rectangular tests by indirect calorimetry. The anaerobic power was determined using Wingate tests. After 8 weeks supplementation, there was a significant increase in the incremental test in estimated functional threshold power (FTP) (3.23%; p≤0.05) and maximum power (2.68%; p≤0.05) with 2S-Hesperdin compared to placebo. In the rectangular test, there was a significant decrease in VO2 (-8.26%; p≤0.01) and VO2R (-8.88%; p≤0.01) at VT2 in placebo; however, there were no significant differences between groups. In the Wingate test, there was a significant increase (p≤0.05) in peak and relative power in both groups, but without significant differences between groups. Supplementation with an orange extract (2S-hesperdin) 500mg/day improves estimated FTP and maximum power performance in amateur cyclists.
ARTICLE | doi:10.20944/preprints202007.0122.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Transcriptionally controlled tumor protein (TCTP); Tryptophan; Florescence; Flavonoid; Native gel electrophoresis
Online: 7 July 2020 (09:49:17 CEST)
Transcriptionally controlled tumor protein (TCTP) is a highly conserved protein performing a large number of cellular functions by binding with various partner proteins. The importance of its roles in many diseases requires an assay method to find regulatory compounds. However, the molecular characteristics of TCTP made it difficult to search for chemicals interacting with it. In this study, a tryptophan-based assay method was designed and Y151W mutant TCTP was constructed to search binding chemicals. Since there is no tryptophan in the native sequence of TCTP, the incorporation of tryptophan in the Y151W mutant was very effective to establish the method. A flavonoid library was employed to the assay with the method. With the native and Y151W mutant TCTPs, three flavonoids such as morin, myricetin and isobavachalcone have been found to interact with TCTP. Combined with native gel electrophoresis, the binding region of isobavachalcone was suggested to be the flexible loop of TCTP. This approach can be easily applicable to find binding compounds of proteins with similar molecular characteristics of TCTP.
ARTICLE | doi:10.20944/preprints202305.0807.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Flavonoid; Antimicrobial mechanism; Quinone; Menaquinone; Respiratory chain; bacterium; MIC; Staphylococcus aureus; α-Mangostin
Online: 11 May 2023 (05:50:54 CEST)
Plant flavonoids have increasingly paid a close attention to for new antimicrobial agents or adjuvants. In our previous work, it was confirmed that the cell membrane is the major site of plant flavonoids acting on the gram-positive bacteria, and which likely involves the inhibition of the respiratory chain. Inspired by the similar structural and antioxidant characters of plant flavonoids to MKH2, we deduced that the quinone pool is probably a key target of plant flavonoids inhibiting gram-positive bacteria. To verify this, twelve plant flavonoids with six structural subtypes were preliminary selected, and their MICs against gram-positive bacteria were predicted from the antimicrobial quantitative relationship of plant flavonoids to gram-positive bacteria. The results showed they have different antimicrobial activities. After their MICs against S. aureus were determined using broth microdilution method, nine compounds with the MICs ranged from 2 to 4,096 μg/mL or more than 1,024 μg/mL were eventually selected, and then their MICs against S. aureus were determined interfered with different concentrations of MK-4 and the MKs extracted from S. aureus. The results showed that the greater the antibacterial activities of plant flavonoids were, the more greatly their antibacterial activities decreased along with the increase of the interfering concentrations of MK-4 (from 2 to 256 μg/mL) and MK extract (from 4 to 512 μg/mL), and while those, with the MICs equal to or more than 512 μg/mL, decreased a little or remained unchanged. Especially, under the interference of MK-4 (256 μg/mL) and MK extract (512 μg/mL), the MICs of α-mangostin, a compound with greatest inhibitory activity to S. aureus in these twelve plant flavonoids, increased by 16 times and 8 to16 times, respectively. Based on these above, it was proposed that the quinone pool is a key target of plant flavonoids inhibiting gram-positive bacteria, and which likely involves multiple mechanisms including some enzyme and non-enzyme inhibitions.
ARTICLE | doi:10.20944/preprints202011.0177.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Propolis Flavonoid; UPLC-Q/TOF-MS/MS; immunological enhancement; Ferulic acid; Anti-PPV
Online: 4 November 2020 (08:50:29 CET)
Propolis was widely used in health preservation and disease healing, it contains many ingredients. The previous study had been revealed that the propolis has a wide range of efficacy, such as antiviral, immune enhancement, anti-inflammatory and so on, but its antiviral components and underlying mechanism of action remain unknown. In this study, we investigated the chemical composition, and anti-PPV and immunological enhancement of Propolis Flavonoid(PF). Chemical composition of PF was distinguished by UPLC-Q/TOF-MS/MS analysis.The presence and characterized of 26 major components was distinguished in negative ionization modes.To evaluate the effects of PF used as adjuvant on the immune response porcine parvovirus (PPV). Thirty Landrace-Yorkshire hybrid sows were randomly assigned to 3 groups, and the sows in adjuvant groups were intramuscular injected PPV vaccine with 2.0 mL PF adjuvant (PA), oilemulsion adjuvant (OA), respectively. After that, serum hemagglutination inhibition antibody titers, IgM and IgG subclasses, eripheral lymphocyte proliferation activity, and concentrations of cytokines were measured. Results indicated an enhancing effect of PA on IgM, IL-2, IL-4, IFN-γ and the IgG subclass responses. These findings suggested that PA could significantly enhance the immune responses. Furthermore, we screened the chemical components the effective of anti-PPV, Ferulic acid have an excellently anti-PPV effective.
REVIEW | doi:10.20944/preprints201810.0291.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: food allergy; PUFA; flavonoid; vitamin A; vitamin D; vitamin E; immune response; anti-inflammatory
Online: 15 October 2018 (08:38:59 CEST)
Specific nutrients including n-3 long chain polyunsaturated fatty acids (LCPUFAs), flavonoids, vitamin A, D and E are considered to possess protective properties on human health by impacting on immunological reactions. An ‘inflammation-suppressive’ effect appears to be the common denominator of the beneficial effects of most of these dietary components which may protect against the development of chronic immune disorders such as allergy. However, the majority of these promising data are from preclinical studies such as animal disease models, as the majority of clinical studies only indicate associations. PUFAs, especially n-3 LCPUFAs, have been shown to interact with both the sensitization as well as the effector phase in food allergy. However, it should be noted and realised that PUFAs are highly susceptible to lipid oxidation. Flavonoids and fat-soluble vitamins both contain anti-inflammatory properties and are able to act as anti-oxidants as well. Here, we explore the anti-allergic properties of PUFAs, flavonoids and fat-soluble vitamins in order to create an overview and, more importantly, suggest a strategy to target food allergies using these components and combinations thereof. Dietary n-3 LCPUFAs and the above mentioned micronutrients are promising anti‐allergy agents capable of influencing the allergic immune response through multiple and different biological pathways.
ARTICLE | doi:10.20944/preprints202204.0103.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Monochoria angustifolia; Monochoria hastata; Flavonoid; Antioxidant mechanism; Natural populations; Phytochemical profile; Traditional herbal medicine; Phytopharmaceutical
Online: 12 April 2022 (04:08:17 CEST)
Plants of the genus Monochoria have long been utilized in food, cosmetics, and traditional herbal treatment. Thailand has the highest species diversity of this genus and a new member, Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum has been recently described. This plant is called “Siam Violet Pearl” as a common name or “ไข่มุกสีม่วงแห่งสยาม” as its vernacular name in the same meaning in Thai language. Despite their importance, few researches on Monochoria species have been conducted. This study, thus, provided the results to fill in this gap by: i) determining flavonoids phytochemical profiles of 25 natural populations of M. angustifolia covering the whole floristic regions in Thailand, and ii) determining antioxidant activity using various antioxidant assays to investigate the probable mechanism. The results revealed that M. angustifolia presented a higher flavonoid content than the outgroup, M. hastata. Our results also revealed that flavonoids might be used to investigate Monochoria evolutionary connections and for botanical authentication. The various antioxidant assays revealed that M. angustifolia extracts preferentially act through a hydrogen atom transfer antioxidant mechanism. Pearson correlation analysis indicated significant correlations emphasizing that the antioxidant capacity is most probably the result of a complex phytochemical combinations rather than of a single molecule. Altogether, these results showed that this new species provide an attractive alternative starting material with phytochemical variety and antioxidant potential for the phytopharmaceutical industry.
ARTICLE | doi:10.20944/preprints202311.0414.v1
Subject: Medicine And Pharmacology, Complementary And Alternative Medicine Keywords: Perilla frutescens var. acuta; Anti-inflammation; Peroxisome proliferator-activated receptor; Nu-clear factor kappa B; Flavonoid diglucuronide
Online: 7 November 2023 (08:25:51 CET)
Perilla frutense var. acuta (Lamiaceae) has been used to treat indigestion, asthma, and allergies in traditional medicine. In this study, luteolin 7-O-diglucuronide (1), apigenin 7-O-diglucuronide (2), and rosmarinic acid (3) were isolated from the leaves of P. frutescens var. acuta. Various approaches were performed to investigate the anti-inflammatory activity of the isolated compounds (1-3) and their working mechanisms. In silico docking simulation demonstrated that 1-3 would work as a PPAR-α/δ/γ agonist, and in vitro PPAR-α/δ/γ transcriptional assay showed that the Perilla extract and 3 increased PPAR-α luciferase activity [1.71 and 1.61 times of the control (PPAR-α + PPRE, p < 0.001)]. In the NF-κB luciferase assay, 1 suppressed NF-κB activity the most (56.83 % at 5 µM; 74.96 % at 10 µM; 79.86 % at 50 µM). In addition, 1 and 2 inhibited the mRNA expression of NF-κB target genes, including Il6, Mcp1, and Tnfa, at 50 µM, and 3 suppressed the genes at the mRNA level in a dose-dependent manner. We report that 1 and 2 exert anti-inflammatory effects through NF-κB inhibition, and PPAR-α/NF-κB signaling pathway is related to the anti-inflammatory activity of 3.
ARTICLE | doi:10.20944/preprints202311.1542.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: IL-1R; Interleukin– 1 receptor; Il-1 receptor; Glycyrrhiza glabra; Licorice; Flavonoid; Inflammation; Periodontitis; Molecular docking; In silico
Online: 24 November 2023 (02:39:37 CET)
Periodontitis is a disease that originates from gingival tissue, and if left untreated, can cause inflammation to spread to deeper tissues, altering bone homeostasis, and even leading to tooth loss. When the bacteria in plaque reach sufficient numbers, the immune system responds by activating immune cells that will produce cytokines, including interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). These immune signaling molecules will coordinate the inflammatory responses. IL-1 binds to the IL-1 receptor (IL-1R) on the surface of target cells, initiating an inflammatory response by activating intracellular signalling pathways. Inhibition of IL-1R can prevent the interaction of IL-1 with this receptor, thereby halting the activation of the inflammatory pathway. By substituting this connection with active anti-inflammatory substances, it is possible to prevent the contact between IL-1 and IL-1R. The licorice plant, Glycyrrhiza glabra, includes eight types of flavonoids with significant anti-inflammatory potential, namely isoliquiritigenin, glyzaglabrin, prunetin, shinpterocarpin, licochalcone A, glabridin, glisoflavone, and isoangustone A. This study aims to assess the potential of such flavonoids as candidates for periodontitis treatment through molecular docking, using AutoDock Tools v.1.5.6. All tested compounds showed highly stable bonds to IL-1R, with a binding affinity values below -7 kcal/mol. Van der Waals forces, hydrogen bonds, and hydrophobic bonds all contribute to the stability of these interactions. Among the eight tested compounds, glisoflavone, which has a Ki value of 90.89 nM and a ΔG value of -9.61 kcal/mol, has the highest binding stability to IL-1R.
ARTICLE | doi:10.20944/preprints202011.0305.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Leucophyllum frutescens; Total Phenolic Contents (TPC); Total Flavonoid Content (TFC); Total Antioxidant Activity (TAA); DPPH; CUPRAC; FRAP; gas chromatography-mass spectrometry (GC-MS)
Online: 10 November 2020 (12:00:06 CET)
The four solvent extractives obtained from aerial parts of Leucophyllum frutescens were evaluated for their Total Antioxidant Activity (TAA) by ammonium molybdate method, scavenging potential by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Trolox-Equivalent Antioxidant Capacity (TEAC) assays, metal-reducing potential by Cupric Reducing Antioxidant Capacity (CUPRAC) and Ferric Reducing Antioxidant Power (FRAP) assays, Total Phenolic Content (TPC), Total Flavonoid Content (TFC) and their biological activities. The study concluded that BULE exhibited total antioxidant activity (226.235±1.222 mg AA.Eq.gm-1 DE±S.D) by molybdate method, CHLE exhibited more scavenging potential (DPPH 209.589±8.500 mg trolox Eq.gm-1 DE±S.D and TEAC 210.166±7.954 mg trolox Eq.gm-1 DE±S.D) and reducing potential (CUPRAC 646.889±16.889 mg trolox Eq.gm-1 DE±S.D & FRAP 472.981±15.625 mg trolox Eq.gm-1 DE±S.D). Phytochemical quantification concluded high TPC by BULE (189.369±1.393 mg GA.Eq.gm-1 DE±S.D) and high TFC by CHLE (232.458±1.589 mg Qu.Eq.gm-1 DE±S.D). Strong inhibition of α-glucosidase and urease enzymes was observed by HELE (IC50 0.3321±0.007 mg.ml-1±SD) and BULE (IC50 4.09±0.357 mg.ml-1±SD) extractives, respectively. The hemolytic effect shown by hexane extract (HELE) was higher with HA50 25.545±0.927 ug.ml-1±SD whereas methanol (MELE), chloroform (CHLE), and butanol (BULE) exhibited hemolytic effects at higher concentration with HA50 400.067±1.364, 321.394±1.332, and 332.957±0.465 µg.ml-1±SD, respectively. GC-MS profiling of HELE of L. frutescens was performed for qualitative analysis. The principal phytochemicals tentatively identified by GC-MS analysis of HELE accounts for fatty acids (60.221%), lignans (17.687%), ketones (3.358%), phenols (2.584%), sesquiterpenes (1.265%), and aldehydes (0.345%).
ARTICLE | doi:10.20944/preprints202110.0095.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Phenolic compounds; organosolv extraction; spruce bark; Picea abies; GC-MS identification; Total phenolic content; Total flavonoid content; Total tannins content; Saccharide’s content; antiviral properties
Online: 6 October 2021 (09:05:17 CEST)
Enormous quantities of softwood and hardwood tree bark are generated yearly in the pulp and woodworking industry. Chemical compounds which can be found in bark extracts have important biological properties and therefore a high potential for using in the production of special formulations. In the present study, extraction of Picea abies bark with organosolv solvents was investigated to achieve a high yield of desirable compounds. For the extraction four different solvent ratios of ethanol and water were applied. The temperature range of extraction was set between 40 and 100 °C and stirring velocity of 400 rpm. Extractions were performed with a solid/liquid ratio of 1:20. Yields of phenolics, flavonoids and tannins were determined using gallic acid for total phenolic content (TPC), quercetin for total flavonoid content (TFC) and tannic acid for total tannins content (TTC) as calibration compounds. Qualitative analysis of phenolic constituents was performed after their derivatization, by gas chromatography coupled with mass spectrometry identification. The total yield of bark extract of 14.75 wt.% was achieved by using an ethanol/water ratio of 50% (v/v) and a temperature of 100 °C. Gas chromatography results show 9 aromatic carboxylic acids as phenolic acids and quercetin and (+)-catechin as flavonoid compounds. Highest concentrations of TPC = 3.21 mg gallic acid equivalent/g, TCF = 0.62 mg quercetin equivalent/g and TTC = 0.84 tannic acid equivalent/g were determined at the same process conditions by photometric method. This study determined the conditions for organosolv extraction of useful compounds and suggests that some of extractives, e.g., taxifolin and rhamnetin presented in the spruce bark extracts, have antiviral (SARS-CoV-2) effects. Therefore, this warrants further evaluation of the antiviral properties of spruce bark constituents.
ARTICLE | doi:10.20944/preprints201801.0022.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Phaleria macrocarpa; extraction; free radical scavenging activity (DPPH); ferric ion reducing power assay (FRAP); total phenolic content (TPC); total flavonoid content (TFC); response surface methodology (RSM)
Online: 3 January 2018 (10:15:16 CET)
In this study, the optimal condition for the extraction of antioxidants from the fruit Buah Mahkota Dewa (Phaleria macrocarpa) was determined by using Response Surface Methodology (RSM). The optimization was applied using central composite design (CCD) to investigate the three independent variables, namely extraction temperature (oC), extraction time (minutes) and extraction solvent to-feed ratio (%v/v) on the responses of free radical scavenging activity (DPPH), ferric ion reducing power assay (FRAP), total phenolic content (TPC) and total flavonoid content (TFC).The optimal conditions for the antioxidants extraction were found to be extraction temperature (64oC), extraction time (66 minutes) and solvent to-feed ratio (75 %v/v) with the highest percentage yield of DPPH, FRAP, TPC and TFC were 86.85%, 7.47%, 292.86 mg/g and 3.22 mg/g respectively. Moreover, the data were subjected to response surface methodology (RSM) and the results showed that the polynomial equations for all models were significant, did not show lack of fit, and presented adjusted determination coefficients (R2) above 99%, proving the yield of phenolic, flavonoid and antioxidants activities obtained experimentally were close to the predicted values and the suitability of the model employed in RSM to optimize the extraction conditions. Hence, in this study, the fruit from P.macrocarpa could be considered to have the strong antioxidant ability and can be used in various cosmeceutical or medicinal applications.