The purpose of this study was to measure the influence of quercetin on plasma cytokines, leukocyte cytokine mRNA, and related variables in ultramarathoners competing in the 160-km Western States Endurance Run (WSER). Sixty-three runners were randomized to quercetin and placebo groups and under double-blinded methods ingested 1000 mg/day quercetin for 3 weeks before the WSER. Thirty-nine of the ...

8-beta-Hydroxypimar-15-en-19-oic acid (1), taxodione (2), 6,7-dehydro-8-hydrotaxodone (3), quercetin-3-O-beta-D-glucopyranoside (4), and shikimic acid (5) were isolated from the leaves of Taxodium distichum L. (Rich.) for the first time. Previously reported compounds [beta-sitosterol (6), isorhamnetin (7), quercetin (8), isorhamnetin-3-O-alpha-arabinofuranoside (9), quercetin-3-O-a-arabinofuran...

Quercetin is one of the most widely distributed flavonoids present in fruits and vegetables. The present experiments were performed on rats adapted for 3 wk to a semipurified diet supplemented with 0.2% quercetin. The major part of the circulating metabolites of quercetin (91.5%) are glucurono-sulfo conjugates of isorhamnetin (3'-O-methyl quercetin; 89.1 ± 2.1 μM) and of quercetin (14.7 ± 1.7 μ...

Quercetin as one of the key plant secondary metabolite flavonol is ubiquitous in terrestrial plants. In this study, the decrease in sensitivity to lambda-cyhalothrin was observed in quercetin-fed Helicoverpa armigera larvae. In order to figure out the mechanisms underlying the decreased sensitivity of H. armigera larvae to lambda-cyhalothrin by quercetin induction, the changes in carboxylestera...

Although the flavonol quercetin is used as a supplement in commercial dog food, data on quercetin bioavailability in dogs are not available. Thus, we investigated quercetin bioavailability (measured as area under the concentration-time curve) in nine adult beagle dogs at an oral dose of 10 mg/kg body weight (b.w.). The major fraction (>80 %) of flavonols circulating in blood plasma were conjuga...

Albino noninbred weanling male and female rats were fed a basic grain diet (Group 1) or a basic diet supplemented with 33% bracken fern [BF (Group 2)] or 0.1% quercetin [purity, > 99% (Group 3)] for 58 weeks. The quantities of quercetin and kaempferol (a close structural analog) in BF as glycosides were determined to be 0.57 and 1.1 g, respectively, per kg of dried BF. Estimated mean total cumu...

Quercetin is a dietary flavonoid with known antitumor effects against several types of cancers by promoting apoptotic cell death and inducing cell cycle arrest. However, U373MG malignant glioma cells expressing mutant p53 are resistant to a 24 h quercetin treatment. In this study, the anticancer effect of quercetin was reevaluated in U373MG cells, and quercetin was found to be significantly eff...

Fructose-induced hyperinsulinemia is associated with insulin compensative secretion and predicts the onset of type 2 diabetes. In this study, we investigated the preservation of dietary flavonoid quercetin on pancreatic β -cell mass and function in fructose-treated rats and INS-1 β -cells. Quercetin was confirmed to reduce serum insulin and leptin levels and blockade islet hyperplasia in fructo...

Four kaempferol glycosides and five quercetin glycosides have been isolated from a methanolic extract of Paederia scandens var. mairei leaves and stems, in which in addition four un­ known glycosides of kaempferol and quercetin are present in a trace. Nine flavonol glycosides including a new glycoside quercetin 3-0-rutinoside-7-0-xylosylglucoside (paederinin) were identified by PC, HPLC, UV spe...