title: High-dose green tea polyphenols induce nephrotoxicity in dextran sulfate sodium-induced colitis mice by down-regulation of antioxidant enzymes and heat-shock protein expressions.
abstract: Previously, we reported that oral feeding of 1% green tea polyphenols (GTPs) aggravated the dextran sulfate sodium (DSS)-induced colitis in mice. In the present study, we assessed the toxicity of 1% GTPs in several organs from normal and DSS-exposed mice. Sixty-two male ICR mice were initially divided into four groups. Non-treated group (group 1, n = 15) was given standard diet and water, GTPs (group 2, n = 15) received 1% GTPs in diet and water, DSS (group 3, n = 15) received diet and 5% DSS in water, and GTPs + DSS group (group 4, n = 17) received 1% GTPs in diet and 5% DSS in water. We found that group 4 significantly increased (P < 0.05) kidney weight, the levels of serum creatinine and thiobarbituric acid-reactive substances in both kidney and liver, as compared with those in group 3. The mRNA expression levels of antioxidant enzymes and heat-shock proteins (HSPs) in group 4 were lower than those of group 3. For instance, heme oxygenase-1 (HO-1), HSP27, and 90 mRNA in the kidney of group 4 were dramatically down-regulated as compared with those of group 3. Furthermore, 1% GTPs diet decreased the expression of HO-1, NAD(P)H:quinone oxidoreductase 1 (NQO1) and HSP90 in kidney and liver of non-treated mice. Taken together, our results indicate that high-dose GTPs diet disrupts kidney functions through the reduction of antioxidant enzymes and heat-shock protein expressions in not only colitis but also non-treated ICR mice.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Inoue
authors.forename: Satoko
authors.initials: S
authors.lastname: Akiyama
authors.forename: Mari
authors.initials: M
authors.lastname: Maeda-Yamamoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nesumi
authors.forename: Takuji
authors.initials: T
authors.lastname: Tanaka
authors.forename: Akira
authors.initials: A
authors.lastname: Murakami
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D003092:Colitis / Q000139:chemically induced*; D016264:Dextran Sulfate; D015536:Down-Regulation / Q000187:drug effects; D006360:Heat-Shock Proteins / Q000235:genetics*; D051547:Heme Oxygenase-1 / Q000235:genetics; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects; D008297:Male; D051379:Mice; D009929:Organ Size / Q000187:drug effects; D059808:Polyphenols / Q000008:administration & dosage / Q000633:toxicity*; D012333:RNA, Messenger / Q000235:genetics; D013662:Tea / Q000633:toxicity*
chemical_list: D000975:Antioxidants; D006360:Heat-Shock Proteins; D059808:Polyphenols; D012333:RNA, Messenger; D013662:Tea; D016264:Dextran Sulfate; D051547:Heme Oxygenase-1