Flavonoids have been reported to be potent antioxidants and beneficial in the treatment of oxidative stress-related diseases. Quercetin, a major flavonoid naturally occurring in plants, deserves attention because of its beneficial effects observed in various in vitro and in vivo neural damage models; however, the actions of quercetin are paradoxical. In an effort to confirm the neuroprotective ...

The flavonoid quercetin has been reported to inhibit the proliferation of cancer cells, whereas it has no effect on nonneoplastic cells. U87-MG, U251, A172, LN229, and U373 malignant glioma cells were treated with quercetin (50-200 microM). Quercetin did not cause cytotoxicity 24 h after treatment. Combining quercetin with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) strongly...

BACKGROUND Chronic oral quercetin reduces blood pressure and restores endothelial dysfunction in hypertensive animals. However, quercetin (aglycone) is usually not present in plasma, because it is rapidly metabolized into conjugated, mostly inactive, metabolites. The aim of the study is to analyze whether deconjugation of these metabolites is involved in the blood pressure lowering effect of qu...

Quercetin, a flavonoid present in many plants, is reported to be effective in models of neurodegenerative diseases. The aim of the present study was to evaluate the anti-tremor effects of quercetin in 6-hydroxydopamine (6-OHDA)-induced rat model of Parkinson's disease. In rats, quercetin had no effect on apomorphine-induced rotations, but it could significantly attenuate muscle tremor of 6-OHDA...

Flavonoids distribution in three algerian Bupleureum (Apiaceae) species has been investigated. Quercetin (1), quercetin 3-rutinoside (2) and isorhamnetin 3-rutinoside (3) were found in the endemic species B. plantagineum Desf. Three kaempferol glycosides, kaempferol 3-glucoside (4), kaempferol 3-galactoside (5), kaempferol 3-rutinoside (6) and three quercetin glycosides, quercetin 3-rutinoside ...

We have studied the uptake of quercetin aglycone into CaCo-2/TC7 cells in the presence and absence of mixed micelles that are present in the human small intestine. The micelles inhibited the transport of quercetin into the cells. To gain an understanding of why this is the case we examined the solubilisation of quercetin in micelles of differing composition and into pure lipid phases. We did th...

BACKGROUND Eugenia spp. are used in popular medicine in the treatment of pain, diabetes, intestinal disorders and cough. The aim of the work is to evaluate, ex vivo and in vivo, the anti-inflammatory activity of the hydroethanolic extracts of the leaves of Eugenia aurata (EA) and Eugenia punicifolia HBK (EP) upon neutrophils. METHODS Ex vivo, isolated human neutrophils were sensitized by Euge...

PURPOSE To investigate the effect of quercetin on the reversal of tamoxifen resistance in breast cancer cells, and explore the underlying mechanism. METHODS We established a tamoxifen-resistant breast cancer cell line (MCF-7Ca/TAM-R), and exposed it to different concentrations of quercetin (experimental group 1: 10 μM, group 2: 25 μM, and group 3: 50μM). Each group was further subdivided into...

Effects of quercetin, a kind of flavonoids, on the vasodilating actions were investigated. Among the mechanisms for quercetin-induced vasodilatation in rat aorta, the involvement with the Ca(2+) activated K(+) (K(Ca)) channel was examined. Pretreatment with NE (5 microM) or KCl (60 mM) was carried out and then, the modulation by quercetin of the constriction was examined using rat aorta ring st...