Displaying publications 281 - 300 of 586 in total

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  1. Chua LS
    Plant Physiol Biochem, 2016 Sep;106:16-22.
    PMID: 27135814 DOI: 10.1016/j.plaphy.2016.04.040
    The identification of plant metabolites is very important for the understanding of plant physiology including plant growth, development and defense mechanism, particularly for herbal medicinal plants. The metabolite profile could possibly be used for future drug discovery since the pharmacological activities of the indigenous herbs have been proven for centuries. An untargeted mass spectrometric approach was used to identify metabolites from the leaves and stems of Impatiens balsamina using LC-DAD-MS/MS. The putative compounds are mostly from the groups of phenolic, organic and amino acids which are essential for plant growth and as intermediates for other compounds. Alanine appeared to be the main amino acid in the plant because many alanine derived metabolites were detected. There are also several secondary metabolites from the groups of benzopyrones, benzofuranones, naphthoquinones, alkaloids and flavonoids. The widely reported bioactive components such as kaempferol, quercetin and their glycosylated, lawsone and its derivatives were detected in this study. The results also revealed that aqueous methanol could extract flavonoids better than water, and mostly, flavonoids were detected from the leaf samples. The score plots of component analysis show that there is a minor variance in the metabolite profiles of water and aqueous methanolic extracts with 21.5 and 30.5% of the total variance for the first principal component at the positive and negative ion modes, respectively.
    Matched MeSH terms: Flavonoids/analysis
  2. Ismail NA, Jusoh SA
    Interdiscip Sci, 2017 Dec;9(4):499-511.
    PMID: 26969331 DOI: 10.1007/s12539-016-0157-8
    Dengue infections are currently estimated to be 390 million cases annually. Yet, there is no vaccine or specific therapy available. Envelope glycoprotein E (E protein) of DENV mediates viral attachment and entry into the host cells. Several flavonoids have been shown to inhibit HIV-1 and hepatitis C virus entry during the virus-host membrane fusion. In this work, molecular docking method was employed to predict the binding of nine flavonoids (baicalin, baicalein, EGCG, fisetin, glabranine, hyperoside, ladanein, quercetin and flavone) to the soluble ectodomain of DENV type 2 (DENV2) E protein. Interestingly, eight flavonoids were found to dock into the same binding pocket located between the domain I and domain II of different subunits of E protein. Consistent docking results were observed not only for the E protein structures of the DENV2-Thai and DENV2-Malaysia (a homology model) but also for the E protein structures of tick-borne encephalitis virus and Japanese encephalitis virus. In addition, molecular dynamics simulations were performed to further evaluate the interaction profile of the docked E protein-flavonoid complexes. Ile4, Gly5, Asp98, Gly100 and Val151 residues of the DENV2-My E protein that aligned to the same residues in the DENV2-Thai E protein form consistent hydrogen bond interactions with baicalein, quercetin and EGCG during the simulations. This study demonstrates flavonoids potentially form interactions with the E protein of DENV2.
    Matched MeSH terms: Flavonoids/metabolism
  3. Ghasemzadeh A, Jaafar HZ, Juraimi AS, Tayebi-Meigooni A
    Molecules, 2015 Jun 11;20(6):10822-38.
    PMID: 26111171 DOI: 10.3390/molecules200610822
    Secondary metabolite contents (total phenolic, flavonoid, tocopherol, and tocotrienol) and antioxidant activities of Hashemi rice bran extracts obtained by ultrasound-assisted and traditional solvent (ethanol and 50:50 (v/v) ethanol-water) extraction techniques were compared. Phenolic and, flavonoid compounds were identified using ultra-high performance liquid chromatography and method validation was performed. Significant differences (p < 0.05) were observed among the different extraction techniques upon comparison of phytochemical contents and antioxidant activities. The extracts obtained using the ethanol-water (50:50 v/v) ultrasonic technique showed the highest amounts of total phenolics (288.40 mg/100 g dry material (DM)), total flavonoids (156.20 mg/100 g DM), and total tocotrienols (56.23 mg/100 g DM), and the highest antioxidant activity (84.21% 1,1-diphenyl-2-picrylhydrazyl (DPPH), 65.27% β-carotene-linoleic bleaching and 82.20% nitric oxide scavenging activity). Secondary metabolite contents and antioxidant activities of the rice bran extracts varied depending of the extraction method used, and according to their effectiveness, these were organized in a decreasing order as follows: ethanol-water (50:50 v/v) ultrasonic, ethanol-water (50:50 v/v) maceration, ethanol ultrasonic and ethanol maceration methods. Ferulic, gallic and chlorogenic acids were the most abundant phenolic compounds in rice bran extracts. The phytochemical constituents of Hashemi rice bran and its antioxidant properties provides insights into its potential application to promote health.
    Matched MeSH terms: Flavonoids/chemistry*
  4. Loo YC, Hu HC, Yu SY, Tsai YH, Korinek M, Wu YC, et al.
    Phytomedicine, 2023 Feb;110:154643.
    PMID: 36623444 DOI: 10.1016/j.phymed.2023.154643
    BACKGROUND: Skin aging is associated with degradation of collagen by matrix metalloproteinases (MMPs), which leads to loss of skin elasticity and formation of wrinkles. Cosmos caudatus Kunth (CC) has been traditionally claimed as an anti-aging agent in Malaysia. Despite its well-known antioxidant activity, the anti-aging properties of CC was not validated.

    PURPOSE: This study aimed to investigate the anti-aging potential of CC extracts and fractions, particularly their inhibition of collagenase, MMP-1 and MMP-3 activities in human dermal fibroblasts CCD-966SK, followed by isolation, identification and analysis of their bioactive constituents.

    STUDY DESIGN AND METHODS: DPPH assay was firstly used to evaluate the antioxidant activity throughout the bioactivity-guided fractionation. Cell viability was determined using MTS assay. Collagenase activity was examined, while MMP-1 and MMP-3 expression were measured using qRT-PCR and western blotting. Then, chemical identification of pure compounds isolated from CC fractions was done by using ESIMS, 1H and 13C NMR spectroscopies. HPLC analyses were carried out for bioactive fractions to quantify the major components.

    RESULTS: Throughout the antioxidant activity-guided fractionation, fractions CC-E2 and CC-E3 with antioxidant activity and no toxicity towards CCD-966SK cells were obtained from CC 75% ethanol partitioned layer (CC-E). Both fractions inhibited collagenase activity, MMP-1 and MMP-3 mRNA and protein expression, as well as NF-κB activation induced by TNF-α in CCD-966SK cells. 14 compounds, which mainly consists of flavonoids and their glycosides, were isolated. Quercitrin (14.79% w/w) and quercetin (11.20% w/w) were major compounds in CC-E2 and CC-E3, respectively, as quantified by HPLC. Interestingly, both fractions also inhibited the MMP-3 protein expression synergistically, compared with treatment alone.

    CONCLUSION: The quantified CC fractions rich in flavonoid glycosides exhibited skin anti-aging effects via the inhibition of collagenase, MMP-1 and MMP-3 activities, probably through NF-κB pathway. This is the first study reported on MMP-1 and MMP-3 inhibitory activity of CC with its chemical profile, which revealed its potential to be developed as anti-aging products in the future.

    Matched MeSH terms: Flavonoids/pharmacology
  5. Benjamin MAZ, Ng SY, Saikim FH, Rusdi NA
    Molecules, 2022 Sep 30;27(19).
    PMID: 36234995 DOI: 10.3390/molecules27196458
    The therapeutic potential of bamboos has acquired global attention. Nonetheless, the biological activities of the plants are rarely considered due to limited available references in Sabah, Malaysia. Furthermore, the drying technique could significantly affect the retention and degradation of nutrients in bamboos. Consequently, the current study investigated five drying methods, namely, sun, shade, microwave, oven, and freeze-drying, of the leaves of six bamboo species, Bambusa multiplex, Bambusa tuldoides, Bambusa vulgaris, Dinochloa sublaevigata, Gigantochloa levis, and Schizostachyum brachycladum. The infused bamboo leaves extracts were analysed for their total phenolic content (TPC) and total flavonoid content (TFC). The antioxidant activities of the samples were determined via the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays, whereas their toxicities were evaluated through the brine shrimp lethality assay (BSLA). The chemical constituents of the samples were determined using liquid chromatography−tandem mass spectrometry (LC-MS/MS). The freeze-drying method exhibited the highest phytochemical contents and antioxidant activity yield, excluding the B. vulgaris sample, in which the microwave-dried sample recorded the most antioxidant and phytochemical levels. The TPC and TFC results were within the 2.69 ± 0.01−12.59 ± 0.09 mg gallic acid equivalent (GAE)/g and 0.77 ± 0.01−2.12 ± 0.01 mg quercetin equivalent (QE)/g ranges, respectively. The DPPH and ABTS IC50 (half-maximal inhibitory concentration) were 2.92 ± 0.01−4.73 ± 0.02 and 1.89−0.01 to 3.47 ± 0.00 µg/mL, respectively, indicating high radical scavenging activities. The FRAP values differed significantly between the drying methods, within the 6.40 ± 0.12−36.65 ± 0.09 mg Trolox equivalent (TE)/g range. The phytochemical contents and antioxidant capacities exhibited a moderate correlation, revealing that the TPC and TFC were slightly responsible for the antioxidant activities. The toxicity assessment of the bamboo extracts in the current study demonstrated no toxicity against the BSLA based on the LC50 (lethal concentration 50) analysis at >1000 µg/mL. LC-MS analysis showed that alkaloid and pharmaceutical compounds influence antioxidant activities, as found in previous studies. The acquired information might aid in the development of bamboo leaves as functional food items, such as bamboo tea. They could also be investigated for their medicinal ingredients that can be used in the discovery of potential drugs.
    Matched MeSH terms: Flavonoids/pharmacology
  6. Cheong NDH, Mohamed E, Haron N, Camalxaman SN, Abdullah A, Mohamad Yusof MI, et al.
    Med J Malaysia, 2024 Mar;79(Suppl 1):34-39.
    PMID: 38555883
    INTRODUCTION: Parkia speciosa Hassk., commonly known as bitter bean or twisted cluster bean, is a tropical leguminous plant species native to Southeast Asia. The plant's edible pods have been traditionally used in various cuisines, particularly in Malaysian, Thai, and Indonesian cooking. Apart from being used as a food ingredient, the pods of P. speciosa also have a range of potential applications in other fields, including medicine, agriculture, and industry. The pods are said to have several phytochemicals that hold great therapeutic values such as reducing inflammation, improving digestion, and lowering blood sugar levels. However, there is limited information on the specific phytochemical contents of the pods in the literature. Thus, the aim of this study is to quantify the total phenolic and flavonoid compounds and to determine the concentrations of four selected phytochemical compounds in the P. speciosa pod extract (PSPE).

    MATERIALS AND METHODS: Quantification of the total phenolic (TPC) and flavonoid contents (TFC) in PSPE were done via colourimetric methods; and the determination of the concentrations of four specific phytochemicals (gallic acid, caffeic acid, rutin, and quercetin) were done via High- Performance Liquid Chromatography (HPLC).

    RESULTS: Colourimetric determination of PSPE showed TPC and TFC values of 84.53±9.40 mg GAE/g and 11.96±4.51 mg QE/g, respectively. Additional analysis of the phytochemicals using HPLC revealed that there were 6.45±3.36 g/kg, 5.91±1.07 g/kg, 0.39±0.84 g/kg, and 0.19±0.47 g/kg of caffeic acid, gallic acid, rutin, and quercetin, respectively.

    CONCLUSION: The findings show that PSPE contains substantial amounts of caffeic acid, gallic acid, rutin, and quercetin, which may indicate its potential as antibacterial, anti-inflammatory, anti-lipid, and antiviral medicines.

    Matched MeSH terms: Flavonoids/analysis
  7. Ullah F, Irfan M, Khatoon S, Khalil S, Sher A, Alsulami N, et al.
    Braz J Biol, 2025;84:e287016.
    PMID: 39968987 DOI: 10.1590/1519-6984.287016
    The exposure of plant seeds to gamma radiation is a promising prospect to crop improvement through the manipulation of their genetic makeup. Previous studies have shed light on the potential of radiation to enhance the genetic variability. In this study, we investigated the effect of gamma radiation on Pisum sativum seeds under heavy metal (nickel chloride) stress to determine the changes in morpho-biochemical attributes. Morphological parameters such as germination and photosynthetic pigments while biochemical attributes such as protein content, sugar, phenolics, and flavonoids were determined. The results showed that gamma radiation, along with (NiCl2) has a pronounced effect on plant morphology and production. In the biochemical analysis of the range from 50 Gy to 100 Gy, photosynthetic pigments and proteins were significantly associated. Although the 50 Gy dose induced a partial reduction in sugar content while the 100 Gy dose demonstrated a slight improvement relative to the 50 Gy dose. However, the phenol content increased in response to 50 Gy, whereas the flavonoid content decreased compared to the control. In combination with heavy metal (50mM) at Gy doses, the protein, sugar, phenol, and flavonoid contents showed a gradual decrease with the increase in Gy doses. In conclusion, the current study based on observations suggests that the range of gamma radiation from 50 Gy to 100 Gy is suitable for causing the mutant form of seeds. However, further studies should be conducted to determine the precise mechanism, in order to be benefitted from full potential role of gamma radiation in improving productivity under heavy metal stress.
    Matched MeSH terms: Flavonoids/analysis
  8. George S, Ajikumaran Nair S, Johnson AJ, Venkataraman R, Baby S
    J Ethnopharmacol, 2015 Jun 20;168:158-63.
    PMID: 25858510 DOI: 10.1016/j.jep.2015.03.060
    Melicope lunu-ankenda leaves are used to treat diabetes in folklore medicinal practices in India and Malaysia. Here we report the isolation of an O-prenylated flavonoid (3,5,4'-trihydroxy-8,3'-dimethoxy-7-(3-methylbut-2-enoxy)flavone; OPF) from the leaves of M. lunu-ankenda and its antidiabetes activity against type-2 diabetes mellitus (T2DM).
    Matched MeSH terms: Flavonoids/isolation & purification; Flavonoids/pharmacology; Flavonoids/therapeutic use*; Flavonoids/toxicity
  9. Tasnuva ST, Qamar UA, Ghafoor K, Sahena F, Jahurul MHA, Rukshana AH, et al.
    Nat Prod Res, 2019 May;33(10):1495-1499.
    PMID: 29281898 DOI: 10.1080/14786419.2017.1419224
    The aim of the study was to isolate digestive enzymes inhibitors from Mimosa pudica through a bioassay-guided fractionation approach. Repeated silica gel and sephadex LH 20 column chromatographies of bioactive fractions afforded stigmasterol, quercetin and avicularin as digestive enzymes inhibitors whose IC50 values as compared to acarbose (351.02 ± 1.46 μg mL-1) were found to be as 91.08 ± 1.54, 75.16 ± 0.92 and 481.7 ± 0.703 μg mL-1, respectively. In conclusion, M. pudica could be a good and safe source of digestive enzymes inhibitors for the management of diabetes in future.
    Matched MeSH terms: Flavonoids/isolation & purification; Flavonoids/pharmacology
  10. Oo A, Rausalu K, Merits A, Higgs S, Vanlandingham D, Bakar SA, et al.
    Antiviral Res, 2018 02;150:101-111.
    PMID: 29269135 DOI: 10.1016/j.antiviral.2017.12.012
    The past decade has seen the re-emergence of Chikungunya virus (CHIKV) as a major global health threat, affecting millions around the world. Although fatal infections are rare among infected patients, the occurrence of long-lasting polyarthralgia has a significant impact on patients' quality of lives and ability to work. These issues were the stimuli for this study to determine the potential of baicalin, a bioflavonoid, as the novel antiviral compound against CHIKV. It was found that baicalin was well tolerated by Vero, BHK-21 and HEK 293T cells with maximal nontoxic doses >600 μM, ≈ 350 μM and ≈110 μM, respectively. Antiviral assays indicated that baicalin was the most effective inhibitor when tested for its direct virucidal activity with EC50 ≈ 7 μM, followed by inhibition of virus entry into the host cell, attachment of virus particle to cellular receptors and finally intracellular replication of viral RNA genome. In silico analysis using molecular docking demonstrated close interactions between baicalin and CHIKV envelope protein with considerably strong binding affinity of -9.7 kcal/mol. qRT-PCR analysis revealed that baicalin had the greatest effect on the synthesis of viral negative stand RNA with EC50 ≈ 0.4 μM followed by the inhibition of synthesis of positive-strand genomic (EC50 ≈ 13 μM) and subgenomic RNAs (EC50 ≈ 14 μM). These readings indicate that the compound efficiently inhibits replicase complexes formation but is a less potent inhibitor of existing replicase complexes. Coherent with this hypothesis, the use of recombinant CHIKV replicons harboring Renilla luciferase marker showed that replication of corresponding replicon RNAs was only slightly downregulated at higher doses of baicalin, with EC50 > 100 μM. Immunofluorescence and western blotting experiments demonstrated dose-dependent inhibition of expression of different viral proteins. It was also observed that levels of important protein markers for cellular autophagy (LC3) and apoptosis (Bax) were reduced in baicalin treatment groups as compared with untreated virus infected controls. In summary, given its low toxicity and high efficacy against CHIKV, baicalin has great potential to be developed as the novel antiviral compound for CHIKV. In vivo studies to evaluate its activity in a more complexed system represent a necessary step for future analysis.
    Matched MeSH terms: Flavonoids/pharmacology*; Flavonoids/chemistry
  11. Duangjai A, Nuengchamnong N, Lee LH, Goh BH, Saokaew S, Suphrom N
    Nat Prod Res, 2019 May;33(10):1491-1494.
    PMID: 29258345 DOI: 10.1080/14786419.2017.1416386
    Azadirachta indica has long been used in traditional medicine. This study focused on isolation and characterisation of active ingredients in the extract, its fractions (NF-EA, NF-AQ, NF-G) and its effect on the cholesterol absorption activity. The NF-EA fraction was identified by marker compounds by LC-ESI-QTOF/MS. Cholesterol absorption activity was performed by measuring the solubility and size of cholesterol micelles. The intestinal motility was also examined by isolated rat's ileum to test the contraction. The extract and its fractions consist of flavonoids and phenolic compounds, like quercetin, kaempferol and myricetin. We found that A. indica extract and NF-EA increase cholesterol micelles size, while the extract, NF-AQ, myricetin and quercetin, reduced the solubility of cholesterol in micelles. The extract and quercetin inhibited the contraction induced by KCl up to 29 and 18%, respectively, and also decreased CaCl2-induced contraction. This finding is in support to traditional uses of A. indica as cholesterol-lowering agents and regulator of gastrointestinal motility.
    Matched MeSH terms: Flavonoids/analysis; Flavonoids/pharmacology
  12. Adom MB, Taher M, Mutalabisin MF, Amri MS, Abdul Kudos MB, Wan Sulaiman MWA, et al.
    Biomed Pharmacother, 2017 Dec;96:348-360.
    PMID: 29028587 DOI: 10.1016/j.biopha.2017.09.152
    The medicinal benefits of Plantago major have been acknowledged around the world for hundreds of years. This plant contains a number of effective chemical constituents including flavonoids, alkaloids, terpenoids, phenolic acid derivatives, iridoid glycosides, fatty acids, polysaccharides and vitamins which contribute to its exerting specific therapeutic effects. Correspondingly, studies have found that Plantago major is effective as a wound healer, as well as an antiulcerative, antidiabetic, antidiarrhoeal, anti-inflammatory, antinociceptive, antibacterial, and antiviral agent. It also combats fatigue and cancer, is an antioxidant and a free radical scavenger. This paper provides a review of the medicinal benefits and chemical constituents of Plantago major published in journals from year 1937 to 2015 which are available from PubMed, ScienceDirect and Google Scholar.
    Matched MeSH terms: Flavonoids/isolation & purification; Flavonoids/chemistry*
  13. Agatonovic-Kustrin S, Morton DW, Adam A, Mizaton HH, Zakaria H
    J Chromatogr A, 2017 Dec 29;1530:192-196.
    PMID: 29132827 DOI: 10.1016/j.chroma.2017.11.012
    The steady increase of diabetes is becoming a major burden on health care systems. As diabetic complications arise from oxidative stress, an antioxidant therapy along with anti-diabetic drugs is recommended. Myrmecodia or ant plant is highly valued as a traditional medicine in West Papua. It is used as an alternative treatment for diabetes, as the substances produced by ants can reduce blood sugar levels. The aim of this study was to develop and establish high-performance thin-layer chromatographic (HPTLC)-bioautographic methods to measure the antioxidant and hypoglycemic effects in different extracts from Myrmecodia platytyrea and to compare them with sterol content. Antioxidant activity in methanol, ethanol, dichloromethane (DCM) and ethyl acetate (EA) extracts were measured with a direct HPTLC-2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) assay, while hypoglycemic effects were assessed using a newly developed α-amylase inhibitory activity assay. Stigmasterol is observed, after derivatization with anisaldehyde, as purple colored zones under visible light at hRF values of 0.66. The highest antioxidant activity was observed in the ethanol extract which is rich in polyphenols and flavonoids, while the DCM extract did not show antioxidant activity, but had significant α-amylase inhibitory activity. The highest α-amylase inhibitory activity was observed in the EA and DCM extracts and was related to their stigmasterol content.
    Matched MeSH terms: Flavonoids/pharmacology; Flavonoids/therapeutic use
  14. Saleem H, Htar TT, Naidu R, Zengin G, Ahmad I, Ahemad N
    Nat Prod Res, 2020 Sep;34(18):2602-2606.
    PMID: 30600720 DOI: 10.1080/14786419.2018.1543684
    In this study, phytochemical composition, antioxidant, enzyme inhibition and cytotoxic activities of methanol and dichloromethane (DCM) extracts of Bougainvillea glabra (B. glabra) flowers were investigated. Methanol extract was found to have higher total bioactive contents and UHPLC-MS analysis of methanol extract revealed the presence of well-known phenolic and flavonoid compounds. Antioxidant activities were performed by radical scavenging (DPPH and ABTS), reducing power (FRAP and CUPRAC), phosphomolybdenum (TAC) and metal chelating assays. From our result, we observed that methanol extract had many antioxidant compounds. The DCM extract exhibited higher cholinesterases and α-glucosidase enzyme inhibition, while methanol extract showed significant urease inhibition. Both extracts exhibited strong to moderate cytotoxicity against MCF-7, MDA-MB-231, CaSki, DU-145 and SW-480 cancer cells with IC50 values ranging from 88.49 to 304.7 µg/mL. The findings showed the B. glabra to possess considerable antioxidant, enzyme inhibition and cytotoxic potentials and therefore has potential to discover novel bioactive molecules.
    Matched MeSH terms: Flavonoids/analysis; Flavonoids/isolation & purification
  15. Zakaria ZA, Mahmood ND, Omar MH, Taher M, Basir R
    Pharm Biol, 2019 Dec;57(1):335-344.
    PMID: 31068038 DOI: 10.1080/13880209.2019.1606836
    CONTEXT: Muntingia calabura L. (Muntingiaceae) exerts antioxidant and anti-inflammatory activities, thus, it might be a good hepatoprotective agent.

    OBJECTIVE: This study investigates the effect of methanol extract of M. calabura leaves (MMCL) on hepatic antioxidant and anti-inflammatory activities in CCl4-induced hepatotoxic rat.

    MATERIALS AND METHODS: Sprague Dawley rats (n = 6) were treated (p.o.) with 10% DMSO (Groups 1 and 2), 50 mg/kg N-acetylcysteine (Group 3) or, 50, 250, or 500 mg/kg MMCL (Groups 4-6) for 7 consecutive days followed by pretreatment (i.p.) with vehicle (Group 1) or 50% CCl4 in olive oil (v/v) (Groups 2-6) on day 7th. Plasma liver enzymes and hepatic antioxidant enzymes and pro-inflammatory cytokines concentrations were measured while liver histopathology was examined.

    RESULTS: MMCL, at 500 mg/kg, significantly (p 

    Matched MeSH terms: Flavonoids/isolation & purification; Flavonoids/therapeutic use*
  16. Monowar T, Rahman MS, Bhore SJ, Raju G, Sathasivam KV
    Biomed Res Int, 2019;2019:6951927.
    PMID: 30868071 DOI: 10.1155/2019/6951927
    Secondary bioactive compounds of endophytes are inevitable biomolecules of therapeutical importance. In the present study, secondary metabolites profiling of an endophytic bacterial strain, Acinetobacter baumannii, were explored using GC-MS study. Presence of antioxidant substances and antioxidant properties in chloroform (CHL), diethyl ether (DEE), and ethyl acetate (EA) crude extracts of the endophytic bacteria were studied. Total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferrous ion chelating assay were evaluated. A total of 74 compounds were identified from the GC-MS analysis of the EA extract representing mostly alkane compounds followed by phenols, carboxylic acids, aromatic heterocyclic compounds, ketones, aromatic esters, aromatic benzenes, and alkenes. Among the two phenolic compounds, namely, phenol, 2,4-bis(1,1-dimethylethyl)- and phenol, 3,5-bis(1,1-dimethylethyl)-, the former was found in abundance (11.56%) while the latter was found in smaller quantity (0.14%). Moreover, the endophytic bacteria was found to possess a number of metal ions including Fe(II) and Cu(II) as 1307.13 ± 2.35 ppb and 42.38 ± 0.352 ppb, respectively. The extracts exhibited concentration dependent antioxidant and prooxidant properties at high and low concentrations, respectively. The presence of phenolic compounds and metal ions was believed to play an important role in the antioxidant and prooxidant potentials of the extracts. Further studies are suggested for exploring the untapped resource of endophytic bacteria for the development of novel therapeutic agents.
    Matched MeSH terms: Flavonoids/metabolism; Flavonoids/chemistry
  17. Hellal K, Maulidiani M, Ismail IS, Tan CP, Abas F
    Molecules, 2020 Mar 10;25(5).
    PMID: 32164186 DOI: 10.3390/molecules25051247
    Claims of effective therapy against diabetes using plants including Peganum harmala L., Zygophyllum album, Anacyclus valentinus L., Ammodaucus leucotrichus, Lupinus albus, and Marrubium vulgare in Algerian empirical medicine prompted our interest in evaluating their antidiabetic activity by screening their free radical scavenging (DPPH), α-glucosidase, and nitric oxide (NO) inhibitory activities as well as the total phenolic content (TPC). Extracts of the selected plants were prepared using different ratios of ethanol (0, 50, 80, and 100%). In this study, 100%, and 80% ethanol extracts of L. albus were found to be the most potent, in inhibiting α-glucosidase activity with IC50 values of 6.45 and 8.66 μg/mL, respectively. The 100% ethanol extract of A. leucotrichus exhibited the highest free radical scavenging activity with an IC50 value of 26.26 μg/mL. Moreover, the highest TPC of 612.84 μg GAE/mg extract was observed in M. vulgare, extracted with 80% ethanol. Metabolite profiling of the active extract was conducted using 1H-NMR metabolomics. Partial least square analysis (PLS) was used to assess the relationship between the α-glucosidase inhibitory activity of L. albus and the metabolites identified in the extract. Based on the PLS model, isoflavonoids (lupinoisoflavone G, lupisoflavone, lupinoisolone C), amino acids (asparagine and thiamine), and several fatty acids (stearic acid and oleic acid) were identified as metabolites that contributed to the inhibition of α-glucosidase activity. The results of this study have clearly strengthened the traditional claim of the antihyperglycemic effects of L. albus.
    Matched MeSH terms: Flavonoids/pharmacology; Flavonoids/chemistry
  18. Khor CY, Khoo BY
    Biotechnol Lett, 2020 Aug;42(8):1581-1595.
    PMID: 32385743 DOI: 10.1007/s10529-020-02904-2
    OBJECTIVE: This study aimed to examine the metabolising effect of chrysin by investigating the mRNA expression levels of PPARα and its related cellular mechanisms in HCT116 cells.

    RESULTS: The mRNA expression of PPARα was significantly induced in HCT116 cells following treatment with chrysin for 36 h, but the mRNA expression of PPARα was inhibited, when the cells were treated with a combination of chrysin and MK886 (PPARα inhibitor). This phenomenon proved that the incorporation of MK886 lowers the expression levels of PPARα, thus enabling us to study the function of PPARα. The cell population of the G0/G1 phase significantly increased in chrysin-treated cells, which was accompanied by a decrease in the percentage of S phase cell population after 12 h of treatment. However, treatments of HCT116 cells with chrysin only or a combination of chrysin and MK886 did not show the opposite situation in the G0/G1 and S phase cell populations, indicating that the expression of PPARα may not be associated with the cell cycle in the treated cells. The migration rate in chrysin-treated HCT116 cells was reduced significantly after 24 and 36 h of treatments. However, the activity was revived, when the expression of PPARα was inhibited, indicating that the migration activity of chrysin-treated cells is likely correlated with the expression of PPARα. Comparison of the CYP2S1 and CYP1B1 mRNA expression in chrysin only treated, and a combination of chrysin and MK886-treated HCT116 cells for 24 and 36 h showed a significant difference in the expression levels, indicating that PPARα inhibitor could also modify the expression of CYP2S1 and CYP1B1.

    CONCLUSION: The study indicates that PPARα may play an essential role in regulating the migration activity, and the expression of CYP2S1 and CYP1B1 in chrysin-treated colorectal cancer cells.

    Matched MeSH terms: Flavonoids/pharmacokinetics; Flavonoids/pharmacology*
  19. Muchtaridi M, Fauzi M, Khairul Ikram NK, Mohd Gazzali A, Wahab HA
    Molecules, 2020 Sep 01;25(17).
    PMID: 32882868 DOI: 10.3390/molecules25173980
    Over the years, coronaviruses (CoV) have posed a severe public health threat, causing an increase in mortality and morbidity rates throughout the world. The recent outbreak of a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the current Coronavirus Disease 2019 (COVID-19) pandemic that affected more than 215 countries with over 23 million cases and 800,000 deaths as of today. The situation is critical, especially with the absence of specific medicines or vaccines; hence, efforts toward the development of anti-COVID-19 medicines are being intensively undertaken. One of the potential therapeutic targets of anti-COVID-19 drugs is the angiotensin-converting enzyme 2 (ACE2). ACE2 was identified as a key functional receptor for CoV associated with COVID-19. ACE2, which is located on the surface of the host cells, binds effectively to the spike protein of CoV, thus enabling the virus to infect the epithelial cells of the host. Previous studies showed that certain flavonoids exhibit angiotensin-converting enzyme inhibition activity, which plays a crucial role in the regulation of arterial blood pressure. Thus, it is being postulated that these flavonoids might also interact with ACE2. This postulation might be of interest because these compounds also show antiviral activity in vitro. This article summarizes the natural flavonoids with potential efficacy against COVID-19 through ACE2 receptor inhibition.
    Matched MeSH terms: Flavonoids/pharmacology*; Flavonoids/chemistry
  20. Yahya HM, Day A, Lawton C, Myrissa K, Croden F, Dye L, et al.
    Eur J Nutr, 2016 Aug;55(5):1839-47.
    PMID: 26210882 DOI: 10.1007/s00394-015-1001-3
    BACKGROUND: Establishing and linking the proposed health benefits of dietary polyphenols to their consumption requires measurement of polyphenol intake in appropriate samples and an understanding of factors that influence their intake in the general population.

    METHODS: This study examined polyphenol intake estimated from 3- and 7-day food diaries in a sample of 246 UK women aged 18-50 years. Estimation of the intake of 20 polyphenol subclasses commonly present in foods consumed by the sample studied was done using Phenol-Explorer(®) and USDA polyphenol databases. Women were participants in the Leeds Women's Wellbeing Study (LWW) (n = 143), a dietary intervention study aimed at overweight women (mean age 37.2 ± 9.4 years; mean BMI 30.8 ± 3.1 kg/m(2)), and the Diet and Health Study (DH) (n = 103) which aimed to examine the relationship between polyphenol intake and cognitive function (mean age 25.0 ± 9.0 years; mean BMI 24.5 ± 4.6 kg/m(2)).

    RESULTS: The estimated intake of polyphenol subclasses was significantly different between the two samples (p 

    Matched MeSH terms: Flavonoids/administration & dosage; Flavonoids/analysis
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