Quercetin:3,3',4',5,7-Pentahydroxyflavone dihydrate:Introduction and Its Benefit Applications.

Quercetin Safety and Toxicity.

Quercetin:3,3',4',5,7-Pentahydroxyflavone dihydrate CAS:6151-25-3 EINECS ELINCS No.:204-187-1 Chem IUPAC Name:2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxychromen-4-one bioflavonoid anti-tumour photo picture image Caution:

If you are pregnant or breastfeeding, consult your health care professional before using this product. Quercetin will stain fabrics.

Quercetin is the major flavonoid involved in vegetables and fruits. Quercetin is ingested from the daily diet, but in 1970s it was reported as mutagenic. Quercetin possesses a variety of pharmacological activities, and in order for further clinical application, it is important to evaluate its safety. In Ames test, quercetin is regarded as mutagenic. However, recent in vitro studies indicate that quercetin is protective against genotoxicants, and regarded as antimutagenic. Some in vivo studies including National Toxicology Program reported carcinogenic effect of quercetin in F344 rats. However, the method used in the study was unusual and the result was not reproduced. Most of the results of in vivo studies indicate that quercetin is not carcinogenic. Since 1969, the International Agency for Research on Cancer (IARC) has undertaken a program to evaluate the carcinogenic risk of chemicals. In 1999, IARC concluded that quercetin is not classified carcinogenic to humans. In the U.S. and Europe, supplements of quercetin is commercially available, and beneficial effects of quercetin supplements were reported in clinical trials. Overall, quercetin is genotoxic to salmonella, but its safety upon human application is approved.

Quercetin is a naturally occurring chemical found in our daily diet in fruits and vegetables. Toxicity and carcinogenicity studies of quercetin were conducted in male and female F344/N rats, under conditions which allowed comparison to results of approximately 400 previously tested chemicals. The chemical was administered in the feed for 2-years at concentrations of 0, 1000, 10,000, or 40,000 ppm, and the estimated dose delivered was approximately 40~1900 mg/kg/day. There were no treatment-related effects on survival and no treatment-related clinical signs of toxicity. The high-dose groups had reduced body weight gain in comparison to controls during the last half of the study. At interim evaluations at 6 and 15 months, treatment-related toxic lesions were not observed, but at 2 years toxic and neoplastic lesions were seen in the kidney of male rats, including increased severity of chronic nephropathy, hyperplasia, and neoplasia of the renal tubular epithelium. Under the conditions of these 2- year studies quercetin showed carcinogenic activity in the kidney of the male rat, causing primarily benign tumors of the renal tubular epithelium. Quercetin did not cause tumors at other sites. Quercetin is a genotoxic chemical, but the neoplastic response observed in the kidney may be due in part to a combination of nongenotoxic and genotoxic events.