Quercetin

 Description
Quercetin is a flavonoid compound found in the bark and rinds of many plants and fruits.1 The estimated human normal dietary intake of quercetin, primarily as glycosides, is 0.**0.2 mg/kg.2 Quercetin is present in much greater amounts in nutritional supplements. Quercetin is carcinogenic in male rats, inducing renal adenomas when fed at 2,**0 mg/kg.3 Quercetin has been reported to inhibit phosphodiesterases of both cGMP and cAMP.4,5 1 Gschwendt, M., Horn, F., Kittstein, W., et al. Inhibition of the calcium- and phospholipid-dependent protein kinase activity from mouse brain cytosol by quercetin.. Biochem Biophys Res Commun **7(2) ******7 (***3).
2 Young, J.F., Nielsen, S.E., Haraldsdottir, J., et al. Effect of fruit juice intake on urinary quercetin excretion and biomarkers of antioxidative status.. Am J Clin Nutr *9(1) ****4 (***9).
3 . Toxicology and carcinogenesis studies of quercetin in F**4 rats. National Toxicology Program ****1 (***2 Sep 1).
4 Ruckstuhl, M., Beretz, A., and Anton, R. Flavonoids are selective cyclic GMP phosphodiesterase inhibitors.. Biochem Pharmacol *8(4) ******8 (***9).
5 Lang, D.R., and Racker, E. Effect of quercetin and F1 inhibitor on mitochondrial ATPase and energy-linked reactions in submitochondrial particles.. Biochim Biophys Acta **3(2) ******6 (***4).