Displaying publications 1 - 20 of 41 in total

  1. Vishwas S, Kumar R, Khursheed R, Ramanunny AK, Kumar R, Awasthi A, et al.
    Curr Neuropharmacol, 2023;21(7):1558-1574.
    PMID: 35950245 DOI: 10.2174/1570159X20666220810105421
    Quercetin (Qu), a dietary flavonoid, is obtained from many fruits and vegetables such as coriander, broccoli, capers, asparagus, onion, figs, radish leaves, cranberry, walnuts, and citrus fruits. It has proven its role as a nutraceutical owing to numerous pharmacological effects against various diseases in preclinical studies. Despite these facts, Qu and its nanoparticles are less explored in clinical research as a nutraceutical. The present review covers various neuroprotective actions of Qu against various neurodegenerative diseases (NDs) such as Alzheimer's, Parkinson's, Huntington's, and Amyotrophic lateral sclerosis. A literature search was conducted to systematically review the various mechanistic pathways through which Qu elicits its neuroprotective actions and the challenges associated with raw Qu that compromise therapeutic efficacy. The nanoformulations developed to enhance Qu's therapeutic efficacy are also covered. Various ongoing/completed clinical trials related to Qu in treating various diseases, including NDs, are also tabulated. Despite these many successes, the exploration of research on Qu-loaded nanoformulations is limited mostly to preclinical studies, probably due to poor drug loading and stability of the formulation, time-consuming steps involved in the formulation, and their poor scale-up capacity. Hence, future efforts are required in this area to reach Qu nanoformulations to the clinical level.
    Matched MeSH terms: Quercetin/pharmacology
  2. Yan L, Vaghari-Tabari M, Malakoti F, Moein S, Qujeq D, Yousefi B, et al.
    Crit Rev Food Sci Nutr, 2023;63(28):9163-9186.
    PMID: 35468007 DOI: 10.1080/10408398.2022.2067825
    Various studies, especially in recent years, have shown that quercetin has beneficial therapeutic effects in various human diseases, including diabetes. Quercetin has significant anti-diabetic effects and may be helpful in lowering blood sugar and increasing insulin sensitivity. Quercetin appears to affect many factors and signaling pathways involved in insulin resistance and the pathogenesis of type 2 of diabetes. TNFα, NFKB, AMPK, AKT, and NRF2 are among the factors that are affected by quercetin. In addition, quercetin can be effective in preventing and ameliorating the diabetic complications, including diabetic nephropathy, cardiovascular complications, neuropathy, delayed wound healing, and retinopathy, and affects the key mechanisms involved in the pathogenesis of these complications. These positive effects of quercetin may be related to its anti-inflammatory and anti-oxidant properties. In this article, after a brief review of the pathogenesis of insulin resistance and type 2 diabetes, we will review the latest findings on the anti-diabetic effects of quercetin with a molecular perspective. Then we will review the effects of quercetin on the key mechanisms of pathogenesis of diabetes complications including nephropathy, cardiovascular complications, neuropathy, delayed wound healing, and retinopathy. Finally, clinical trials investigating the effect of quercetin on diabetes and diabetes complications will be reviewed.
    Matched MeSH terms: Quercetin/pharmacology
  3. Mohammed HA, Sulaiman GM, Anwar SS, Tawfeeq AT, Khan RA, Mohammed SAA, et al.
    Nanomedicine (Lond), 2021 09;16(22):1937-1961.
    PMID: 34431317 DOI: 10.2217/nnm-2021-0070
    Aims: To evaluate the anti breast-cancer activity, biocompatibility and toxicity of poly(d,l)-lactic-co-glycolic acid (PLGA)-encapsulated quercetin nanoparticles (Q-PLGA-NPs). Materials & methods: Quercetin was nano-encapsulated by an emulsion-diffusion process, and the nanoparticles were fully characterized through Fourier transform infrared spectroscopy, x-ray diffractions, FESEM and zeta-sizer analysis. Activity against CAL51 and MCF7 cell lines were assessed by DNA fragmentation assays, fluorescence microscopy, and acridine-orange, and propidium-iodide double-stainings. Biocompatibility towards red blood cells and toxicity towards mice were also explored. Results: The Q-PLGA-NPs exhibited apoptotic activity against the cell lines. The murine in vivo studies showed no significant alterations in the liver and kidney's functional biomarkers, and no apparent abnormalities, or tissue damages were observed in the histological images of the liver, spleen, lungs, heart and kidneys. Conclusion: The study established the preliminary in vitro efficacy and in vivo safety of Q-PLGA-NPs as a potential anti-breast cancer formulation.
    Matched MeSH terms: Quercetin/pharmacology
  4. Magalingam KB, Radhakrishnan A, Haleagrahara N
    Int J Immunopathol Pharmacol, 2016 Mar;29(1):30-9.
    PMID: 26542606 DOI: 10.1177/0394632015613039
    There is increasing evidence that free radicals induced oxidative stress is a major causative agent in the pathogenesis of neurodegenerative diseases, particularly Parkinson's disease. Quercetin glycosides, namely rutin and isoquercitrin, are flavonoid polyphenol compounds found ubiquitously in fruits and vegetables and have been known to possess antioxidant effects. This study was designed to compare the neuroprotective effects of quercetin glycosides rutin and isoquercitrin in 6-OHDA-induced rat pheochromocytoma (PC-12) cells. The results showed that both rutin and isoquercitrin significantly increased antioxidant enzymes, catalase, superoxide dismutase, glutathione peroxidase, and glutathione level that were attenuated by 6-OHDA in PC-12 cells. There was no significant difference in the activation of glutathione and glutathione peroxidase enzymes between rutin and isoquercitrin. These two glycosides were equally effective in suppressing lipid peroxidation in 6-OHDA-induced PC-12 cells as both compounds suppressed the malondialdehyde generation and prevented cell damage. In conclusion, quercetin glycosides rutin and isoquercetrin are having a significant neuroprotective effect against 6-OHDA toxicity in PC-12 cells.
    Matched MeSH terms: Quercetin/pharmacology
  5. Teh SS, Ee GC, Mah SH, Lim YM, Ahmad Z
    Molecules, 2013 Feb 04;18(2):1985-94.
    PMID: 23381024 DOI: 10.3390/molecules18021985
    The cytotoxic structure-activity relationships among a series of xanthone derivatives from Mesua beccariana, Mesua ferrea and Mesua congestiflora were studied. Eleven xanthone derivatives identified as mesuarianone (1), mesuasinone (2), mesuaferrin A (3), mesuaferrin B (4), mesuaferrin C (5), 6-deoxyjacareubin (6), caloxanthone C (7), macluraxanthone (8), 1,5-dihydroxyxanthone (9), tovopyrifolin C (10) and α-mangostin (11) were isolated from the three Mesua species. The human cancer cell lines tested were Raji, SNU-1, K562, LS-174T, SK-MEL-28, IMR-32, HeLa, Hep G2 and NCI-H23. Mesuaferrin A (3), macluraxanthone (8) and α-mangostin (11) showed strong cytotoxicities as they possess significant inhibitory effects against all the cell lines. The structure-activity relationship (SAR) study revealed that the diprenyl, dipyrano and prenylated pyrano substituent groups of the xanthone derivatives contributed towards the cytotoxicities.
    Matched MeSH terms: Quercetin/pharmacology
  6. Jalal TK, Khan AYF, Natto HA, Abdull Rasad MSB, Arifin Kaderi M, Mohammad M, et al.
    Nutr Cancer, 2019;71(5):792-805.
    PMID: 30614285 DOI: 10.1080/01635581.2018.1516790
    Nine phenolic compounds were identified and quantified in Artocarpus altilia fruit. One of the main compounds was quercetin, which is the major class of flavonoids has been identified and quantified in pulp part of A. altilis fruit of methanol extract. The aim of this study was to evaluate in vitro cytotoxic assay. Inhibitory concentration 50% concentration was determined using trypan blue exclusion assay. Apoptosis induction and cell cycle regulation were studied by flow cytometric analysis. The expression of apoptosis and cell cycle-related regulatory genes were assessed by RT-qPCR study of the methanol extract of pulp part on human lung carcinoma (A549) cell line. A significant increase of cells at G2/M phases was detected (P quercetin in pulp part, 78% of total flavonoids. Taken together, these findings suggested that A. altilis induces apoptosis in a mitochondrial-dependent pathway by releasing and upregulating CYTOCHROME C expression and regulates the expression of downstream apoptotic components, including BCL-2 and BAX.
    Matched MeSH terms: Quercetin/pharmacology*
  7. Wong SK, Chin KY, Ima-Nirwana S
    Int J Mol Sci, 2020 Sep 03;21(17).
    PMID: 32899435 DOI: 10.3390/ijms21176448
    Quercetin is a flavonoid abundantly found in fruits and vegetables. It possesses a wide spectrum of biological activities, thus suggesting a role in disease prevention and health promotion. The present review aimed to uncover the bone-sparing effects of quercetin and its mechanism of action. Animal studies have found that the action of quercetin on bone is largely protective, with a small number of studies reporting negative outcomes. Quercetin was shown to inhibit RANKL-mediated osteoclastogenesis, osteoblast apoptosis, oxidative stress and inflammatory response while promoting osteogenesis, angiogenesis, antioxidant expression, adipocyte apoptosis and osteoclast apoptosis. The possible underlying mechanisms involved are regulation of Wnt, NF-κB, Nrf2, SMAD-dependent, and intrinsic and extrinsic apoptotic pathways. On the other hand, quercetin was shown to exert complex and competing actions on the MAPK signalling pathway to orchestrate bone metabolism, resulting in both stimulatory and inhibitory effects on bone in parallel. The overall interaction is believed to result in a positive effect on bone. Considering the important contributions of quercetin in regulating bone homeostasis, it may be considered an economical and promising agent for improving bone health. The documented preclinical findings await further validation from human clinical trials.
    Matched MeSH terms: Quercetin/pharmacology*
  8. Shahzad H, Giribabu N, Karim K, Muniandy S, Kassim NM, Salleh N
    Reprod Toxicol, 2017 04;69:276-285.
    PMID: 28341573 DOI: 10.1016/j.reprotox.2017.03.012
    Effects of quercetin on uterine fluid volume and aquaporin (AQP) expression in the uterus were investigated. Estradiol (E) or estradiol followed by progesterone (E+P) were given to ovariectomised rats with or without quercetin (10, 50 or 100mg/kg/day) treatment. Uteri were harvested and its inner/outer circumference ratio was determined. AQP-1, 2, 5 and 7 mRNA and protein levels in uterus were quantified by Real-time PCR and Western blotting respectively. Protein distribution was observed by immunohistochemistry. Administration of quercetin in E-treated rats decreased the uterine fluid volume and uterine AQP-2 expression. In E+P-treated rats, administration of 100mg/kg/day quercetin increased uterine fluid volume, AQP-1 and 2 expression but decreased AQP-7 expression in uterus. AQP-1 was distributed in stromal blood vessels while AQP-2, 5 and 7 were distributed in uterine epithelium.

    CONCLUSIONS: Quercetin-induced changes in uterine fluid volume and AQP subunits expression in uterus could affect the uterine reproductive functions under different sex-steroid influence.

    Matched MeSH terms: Quercetin/pharmacology*
  9. Vimalraj S, Rajalakshmi S, Raj Preeth D, Vinoth Kumar S, Deepak T, Gopinath V, et al.
    Mater Sci Eng C Mater Biol Appl, 2018 Feb 01;83:187-194.
    PMID: 29208278 DOI: 10.1016/j.msec.2017.09.005
    Copper(II) complex of quercetin Cu+Q, mixed ligand complexes, quercetin-Cu(II)-phenanthroline [Cu+Q(PHt)] and quercetin-Cu(II)-neocuproine [Cu+Q(Neo)] have been synthesized and characterized. From the FT-IR spectroscopic studies, it was evident that C-ring of quercetin is involved in the metal chelation in all the three copper complexes. C-ring chelation was further proven by UV-Visible spectra and the presence of Cu(II) from EPR spectroscopic investigations. These complexes were found to have osteogenic and angiogenic properties, observed through in vitro osteoblast differentiation and chick embryo angiogenesis assay. In osteoblast differentiation, quercetin-Cu(II) complexes treatment increased calcium deposition and alkaline phosphatase activity (ALP) activity at the cellular level and stimulated Runx2 mRNA and protein, ALP mRNA and type 1 collagen mRNA expression at the molecular level. Among the complexes, Q+Cu(PHt) showed more effects on osteoblast differentiation when compared to that of other two copper complexes. Additionally, Q+Cu(Neo) showed more effect compared to Q+Cu. Furthermore, the effect of these complexes on osteoblast differentiation was confirmed by the expression of osteoblast specific microRNA, pre-mir-15b. The chick embryo angiogenesis assay showed that angiogenic parameters such as blood vessel length, size and junctions were stimulated by these complexes. Thus, the present study demonstrated that quercetin copper(II) complexes exhibit as a pharmacological agent for the orthopedic application.
    Matched MeSH terms: Quercetin/pharmacology*
  10. Alrawaiq NS, Atia A, Abdullah A
    Oxid Med Cell Longev, 2023;2023:9291417.
    PMID: 37077659 DOI: 10.1155/2023/9291417
    Certain dietary chemicals influenced the expression of chemopreventive genes through the Nrf2-Keap1 pathway. However, the difference in Nrf2 activation potency of these chemicals is not well studied. This study is aimed at determining the difference in the potency of liver Nrf2 nuclear translocation induced by the administration of equal doses of selected dietary chemicals in mice. Male ICR white mice were administered 50 mg/kg of sulforaphane, quercetin, curcumin, butylated hydroxyanisole, and indole-3-carbinol for 14 days. On day 15, the animals were sacrificed, and their livers were isolated. Liver nuclear extracts were prepared, and Nrf2 nuclear translocation was detected through Western blotting. To determine the implication of the Nrf2 nuclear translocation on the expression levels of several Nrf2-regulated genes, liver RNA was extracted for qPCR assay. Equal doses of sulforaphane, quercetin, curcumin, butylated hydroxyanisole, and indole-3-carbinol significantly induced the nuclear translocation of Nrf2 with different intensities and subsequently increased the expression of Nrf2-regulated genes with an almost similar pattern as the Nrf2 nuclear translocation intensities (sulforaphane > butylated hydroxyanisole = indole-3-carbinol > curcumin > quercetin). In conclusion, sulforaphane is the most potent dietary chemical that induces the Nrf2 translocation into the nuclear fraction in the mouse liver.
    Matched MeSH terms: Quercetin/pharmacology
  11. Sirat HM, Rezali MF, Ujang Z
    J Agric Food Chem, 2010 Oct 13;58(19):10404-9.
    PMID: 20809630 DOI: 10.1021/jf102231h
    Phytochemical and bioactivity studies of the leaves and stem barks of Tibouchina semidecandra L. have been carried out. The ethyl acetate extract of the leaves yielded four flavonoid compounds, identified as quercetin, quercetin 3-O-α-l-(2''-O-acetyl) arabinofuranoside, avicularin, and quercitrin, while the stem barks gave one ellagitannin, identified as 3,3'-O-dimethyl ellagic acid 4-O-α-l-rhamnopyranoside. Evaluation of the antioxidative activity on the crude extracts and pure compounds by electron spin resonance (ESR) and ultraviolet-visible (UV-vis) spectrophotometric assays showed that the pure isolated polyphenols and the EtOAc extract possessed strong antioxidative capabilities. Quercetin was found to be the most active radical scavenger in DPPH-UV and ESR methods with SC(50) values of 0.7 μM ± 1.4 and 0.7 μM ± 0.6 μM, respectively, in the antioxidant assay. A combination of quercetin and quercitrin was tested for synergistic antioxidative capacity;, however, there was no significant improvement observed. Quercetin also exhibited strong antityrosinase activity with a percent inhibition of 95.0% equivalent to the positive control, kojic acid, in the tyrosinase inhibition assay.
    Matched MeSH terms: Quercetin/pharmacology
  12. Johari J, Kianmehr A, Mustafa MR, Abubakar S, Zandi K
    Int J Mol Sci, 2012;13(12):16785-95.
    PMID: 23222683 DOI: 10.3390/ijms131216785
    Japanese encephalitis (JE), a mosquito-borne viral disease, is endemic to the entire east and southeast Asia, and some other parts of the world. Currently, there is no effective therapeutic available for JE; therefore, finding the effective antiviral agent against JEV replication is crucial. In the present study, the in vitro antiviral activity of baicalein and quercetin, two purportedly antiviral bioflavonoids, was evaluated against Japanese encephalitis virus (JEV) replication in Vero cells. Anti-JEV activities of these compounds were examined on different stages of JEV replication cycle. The effects of the compounds on virus replication were determined by foci forming unit reduction assay (FFURA) and quantitative RT-PCR. Baicalein showed potent antiviral activity with IC(50) = 14.28 µg/mL when it was introduced to the Vero cells after adsorption of JEV. Quercetin exhibited weak anti-JEV effects with IC(50) = 212.1 µg/mL when the JEV infected cells were treated with the compound after virus adsorption. However, baicalein exhibited significant effect against JEV adsorption with IC(50) = 7.27 µg/mL while quercetin did not show any anti-adsorption activity. Baicalein also exhibited direct extracellular virucidal activity on JEV with IC(50) = 3.44 µg/mL. However, results of quantitative RT-PCR experiments confirmed the findings from FFURA. This study demonstrated that baicalein should be considered as an appropriate candidate for further investigations, such as the study of molecular and cellular mechanism(s) of action and in vivo evaluation for the development of an effective antiviral compound against Japanese encephalitis virus.
    Matched MeSH terms: Quercetin/pharmacology*
  13. Lutterodt GD
    J Ethnopharmacol, 1989 May;25(3):235-47.
    PMID: 2747259
    The electrically stimulated guinea-pig ileum and spontaneously contracting guinea-pig ileum preparations were employed in studies on the effects of an alcoholic extract and two flavonoid compounds, quercetin and quercetin-3-arabinoside, extracted from the leaves of Psidium guajava. The extract showed a morphine-like inhibition of acetylcholine release in the coaxially stimulated ileum, together with an initial increase in muscular tone, followed by a gradual decrease. The morphine-like inhibition was found to be due to quercetin, starting at concentrations of 1.6 micrograms/ml. The glycoside did not show any such action at concentrations of up to 1.28 mg/ml. The extract inhibited spontaneous contractions in the unstimulated ileum with a concentration-response relationship.
    Matched MeSH terms: Quercetin/pharmacology*
  14. Arya A, Al-Obaidi MM, Shahid N, Bin Noordin MI, Looi CY, Wong WF, et al.
    Food Chem Toxicol, 2014 Sep;71:183-96.
    PMID: 24953551 DOI: 10.1016/j.fct.2014.06.010
    The aim of this study was to investigate the synergistic effects of quercetin (QE) and quinic acid (QA) on a STZ-induced diabetic rat model to determine their potential role in alleviating diabetes and its associated complications. In our study design, diabetic rats were treated with single and combined doses of QE and QA for 45days to analyse their effects on liver, kidney and pancreas tissues. The study result showed that QE and QA treated groups down-regulated hyperglycaemia and oxidative stress by up-regulating insulin and C-peptide levels. Moreover, histological observations of the liver, kidney and pancreas of diabetic rats treated with single and combined doses of QE and QA showed a significant improvement in the structural degeneration. Interestingly, the combination dose of QE and QA (50 mg/kg) exhibited maximum inhibition of the pro-apoptotic protein Bax expression and demonstrate enhancement of the anti-apoptotic protein Bcl-2 expression in the kidney tissues, suggesting a protective role in the kidneys of diabetic rats. Taken together, these results indicates the synergistic effects of QE and QA in ameliorating hyperglycaemia, hyperlipidemia and insulin resistance in diabetic rats and therefore, open a new window of research on the combinatorial therapy of flavonoids.
    Matched MeSH terms: Quercetin/pharmacology*
  15. Ajay M, Achike FI, Mustafa AM, Mustafa MR
    Diabetes Res Clin Pract, 2006 Jul;73(1):1-7.
    PMID: 16378655 DOI: 10.1016/j.diabres.2005.11.004
    The present work examined ex vivo the acute effect of quercetin on diabetic rat aortic ring reactivity in response to endothelium-dependent (acetylcholine, ACh) and endothelium-independent (sodium nitroprusside, SNP) relaxants, and to the alpha(1)-adrenergic agonist phenylephrine (PE). Responses were compared to those of aortic rings from age- and sex-matched euglycemic rats. Compared to euglycemic rat aortic rings, diabetic rings showed less relaxation in response to ACh and SNP, and greater contraction in response to PE. Pretreatment with quercetin (10microM, 20min) increased ACh-induced relaxation and decreased PE-induced contraction in diabetic, but did not affect euglycemic rat aortic ring responses. Following pretreatment with the nitric oxide synthase inhibitor Nomega-nitro-l-arginine methyl ester (l-NAME, 10microM), quercetin reduced PE-induced contractions in both aortic ring types, although l-NAME attenuated the reduction in the diabetic rings. Quercetin did not alter SNP vasodilatory effects in either ring type compared to their respective controls. These findings indicate that quercetin acutely improved vascular responsiveness in blood vessels from diabetic rats, and that these effects were mediated, at least in part, by enhanced endothelial nitric oxide bioavailability. These effects of quercetin suggest the possible beneficial effects of quercetin in vivo in experimental diabetes and possibly in other cardiovascular diseases.
    Matched MeSH terms: Quercetin/pharmacology*
  16. Khursheed R, Singh SK, Wadhwa S, Gulati M, Kapoor B, Jain SK, et al.
    Int J Biol Macromol, 2021 Oct 31;189:744-757.
    PMID: 34464640 DOI: 10.1016/j.ijbiomac.2021.08.170
    The role of mushroom polysaccharides and probiotics as pharmaceutical excipients for development of nanocarriers has never been explored. In the present study an attempt has been made to explore Ganoderma lucidum extract powder (GLEP) containing polysaccharides and probiotics to convert liquid self nanoemulsifying drug delivery system (SNEDDS) into solid free flowing powder. Two lipophilic drugs, curcumin and quercetin were used in this study due to their dissolution rate limited oral bioavailability and poor permeability. These were loaded into liquid SNEDDS by dissolving them into isotropic mixture of Labrafill M1944CS, Capmul MCM, Tween-80 and Transcutol P. The liquid SNEDDS were solidified using probiotics and mushroom polysaccharides as carriers and Aerosil-200 as coating agent. The solidification was carried out using spray drying process. The process and formulation variables for spray drying process of liquid SNEDDS were optimized using Box Behnken Design to attain required powder properties. The release of both drugs from the optimized spray dried (SD) formulation was found to be more than 90%, whereas, it was less than 20% for unprocessed drugs. The results of DSC, PXRD and SEM, showed that the developed L-SNEDDS preconcentrate was successfully loaded onto the porous surface of probiotics, mushroom polysaccharides and Aerosil-200.
    Matched MeSH terms: Quercetin/pharmacology*
  17. Magalingam KB, Radhakrishnan A, Ramdas P, Haleagrahara N
    J Mol Neurosci, 2015 Mar;55(3):609-17.
    PMID: 25129099 DOI: 10.1007/s12031-014-0400-x
    Quercetin glycosides, rutin and isoquercitrin, are potent antioxidants that have been found to possess neuroprotective effect in diseases like Parkinson's and Alzheimer's disease. In the present study, we have examined the gene expression changes with rutin and isoquercitrin pretreatment on 6-hydroxydopamine (6-OHDA)-treated toxicity in rat pheochromocytoma (PC12) cells. PC12 cells were pretreated with rutin or isoquercitrin and subsequently exposed to 6-OHDA. Rutin-pretreated PC12 attenuated the Park2, Park5, Park7, Casp3, and Casp7 genes which were expressed significantly in the 6-OHDA-treated PC12 cells. Rutin upregulated the TH gene which is important in dopamine biosynthesis, but isoquercitrin pretreatment did not affect the expression of this gene. Both rutin and isoquercitrin pretreatments upregulated the ion transport and antiapoptotic genes (NSF and Opa1). The qPCR array data were further validated by qRT-PCR using four primers, Park5, Park7, Casp3, and TH. This finding suggests that changes in the expression levels of transcripts encoded by genes that participate in ubiquitin pathway and dopamine biosynthesis may be involved in Parkinson's disease.
    Matched MeSH terms: Quercetin/pharmacology*
  18. Paydar M, Wong YL, Moharam BA, Wong WF, Looi CY
    Pak J Biol Sci, 2013 Oct 15;16(20):1212-5.
    PMID: 24506026
    Sanchezia speciosa, is a bushy shrub from Acanthaceae family which commonly grows in tropical areas of South and Central America. In this study, we employed MTT assay to test the cytotoxicity of that methanolic fraction of S. speciosa leaves on MCF-7 human breast cancer, SK-MEL-5 human malignant melanoma and human umbilical vein endothelial cells, HUVEC cells. The extract showed highest activity on MCF-7 and moderate cytotoxicity towards SK-MEL-5. In contrast, the extract demonstrated lowest cell growth inhibition activity on HUVEC cells, indicating better selectivity compare to standard drug, doxorubicin. In addition, we also performed ORAC assay to determine the radical scavenging capacity of methanolic extract of S. speciosa leaves. The extract exhibited nearly similar anti-oxidant activity as quercetin, suggesting S. speciosa leaves as a potential source of natural anti-oxidant. To the best of our knowledge, this is the first report on anti-oxidant and cytotoxic activity of S. speciosa.
    Matched MeSH terms: Quercetin/pharmacology
  19. Zandi K, Teoh BT, Sam SS, Wong PF, Mustafa MR, Abubakar S
    Virol J, 2011;8:560.
    PMID: 22201648 DOI: 10.1186/1743-422X-8-560
    Dengue is a major mosquito-borne disease currently with no effective antiviral or vaccine available. Effort to find antivirals for it has focused on bioflavonoids, a plant-derived polyphenolic compounds with many potential health benefits. In the present study, antiviral activity of four types of bioflavonoid against dengue virus type -2 (DENV-2) in Vero cell was evaluated. Anti-dengue activity of these compounds was determined at different stages of DENV-2 infection and replication cycle. DENV replication was measured by Foci Forming Unit Reduction Assay (FFURA) and quantitative RT-PCR. Selectivity Index value (SI) was determined as the ratio of cytotoxic concentration 50 (CC50) to inhibitory concentration 50 (IC50) for each compound.
    Matched MeSH terms: Quercetin/pharmacology
  20. Haleagrahara N, Radhakrishnan A, Lee N, Kumar P
    Eur J Pharmacol, 2009 Oct 25;621(1-3):46-52.
    PMID: 19744476 DOI: 10.1016/j.ejphar.2009.08.030
    Quercetin is a bioflavonoid abundant in onions, apples, tea and red wine and one of the most studied flavonoids. Dietary quercetin intake is suggested to be health promoting, but this assumption is mainly based on mechanistic studies performed in vitro. The objective of this study was to investigate the effect of quercetin on stress-induced changes in oxidative biomarkers in the hypothalamus of rats. Adult male Sprague Dawley rats were subjected to forced swimming stress for 45 min daily for 14 days. Effect of quercetin at three different doses (10, 20 and 30 mg/kg body weight) on serum corticosterone and oxidative biomarkers (lipid hydroperoxides, antioxidant enzymes and total antioxidants) was estimated. Swimming stress significantly increased the serum corticosterone and lipid hydroperoxide levels. A significant decrease in total antioxidant levels and super oxide dismutase, glutathione peroxidase and catalase levels was seen in the hypothalamus after stress and treatment with quercetin significantly increased these oxidative parameters and there was a significant decrease in lipid hydroperoxide levels. These data demonstrate that forced swimming stress produced a severe oxidative damage in the hypothalamus and treatment with quercetin markedly attenuated these stress-induced changes. Antioxidant action of quercetin may be beneficial for the prevention and treatment of stress-induced oxidative damage in the brain.
    Matched MeSH terms: Quercetin/pharmacology*
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