title: Anti- and prooxidant effects of chronic quercetin administration in rats.
abstract: The present study was performed to investigate the effects of chronic administration of quercetin on lipid peroxidation and glutathione concentration in rat liver. Male Sprague-Dawley rats were divided into two groups, one of which was fed a normal diet and the other a vitamin E-free diet. Each of these groups was divided further into three subgroups and treated with quercetin administered orally at either 2 or 20 mg/day or with vehicle for 4 weeks. The concentrations of alpha-tocopherol in serum and liver increased following quercetin treatment, and these increases were significantly greater in rats maintained on a vitamin E-free diet. Quercetin significantly decreased the concentration of malondialdehyde (an indicator of lipid peroxidation) in the liver and this decrease was more pronounced in vitamin E-deprived rats than in those maintained on a normal diet (55-60% and 25-35% decrease in malondialdehyde concentrations, respectively). Quercetin treatment decreased the glutathione concentration and glutathione reductase activity (40 and 34%, respectively) in the liver significantly and to a similar extent in vitamin E-deprived and -undeprived rats. Collectively, these results suggest that quercetin may act not only as an antioxidant, but also as a prooxidant in rats.
authors.affiliation: Department of Biotechnology, Korea University, Anamdong, Sungbuk, Seoul 136-701, South Korea.
authors.forename: Eun Jeong
authors.initials: EJ
authors.lastname: Choi
authors.forename: Kew-Mahn
authors.initials: KM
authors.lastname: Chee
authors.forename: Byung Ho
authors.initials: BH
authors.lastname: Lee
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D015227:Lipid Peroxidation / Q000187:drug effects* / Q000502:physiology; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D016877:Oxidants / Q000008:administration & dosage*; D011794:Quercetin / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014811:Vitamin E Deficiency / Q000378:metabolism
chemical_list: D000975:Antioxidants; D016877:Oxidants; D011794:Quercetin