title: Low and medium but not high doses of green tea polyphenols ameliorated dextran sodium sulfate-induced hepatotoxicity and nephrotoxicity.
abstract: Our previous study indicated that a diet containing a high dose (1%) of green tea polyphenols (GTPs) disrupted liver and kidney function via a reduction in antioxidant enzyme and heat shock protein (HSP) levels in both colitis and non-treated ICR mice. In the present study, we assessed the effects of 0.01%, 0.1%, and 1% dietary GTPs on liver and kidney physiological functioning in dextran sulfate sodium (DSS)-exposed and normal mice. GTPs at 0.01% and 0.1% significantly suppressed DSS-increased serum aspartate 2-oxoglutarate aminotransferase (AST) and alanine aminotransferase (ALT) levels. In contrast, GTPs at 1% increased kidney weight, serum creatinine levels, and thiobarbituric acid-reactive substances (TBARs) in both the kidney and the liver in normal mice, as compared with DSS-exposed mice. GTPs at 0.01% and 0.1% remarkably upregulated the expression of heme oxygenase-1 (HO-1) and heat shock protein 70 (HSP70) mRNA in the liver and kidney of mice exposed to DSS, whereas GTPs at 1% abolished it. Our results indicate that low and medium doses of GTPs have beneficial effects on DSS-induced hepatotoxicity and nephrotoxicity via upregulation of self-protective enzymes, while these effects disappeared at a high dose.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Inoue
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: D000410:Alanine Transaminase / Q000378:metabolism; D000818:Animals; D001219:Aspartate Aminotransferases / Q000378:metabolism; D016264:Dextran Sulfate / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000473:pathology; D017093:Liver Failure / Q000139:chemically induced / Q000178:diet therapy* / Q000473:pathology; D051379:Mice; D059808:Polyphenols / Q000008:administration & dosage* / Q000737:chemistry; D051437:Renal Insufficiency / Q000139:chemically induced / Q000178:diet therapy* / Q000473:pathology; D013662:Tea
chemical_list: D059808:Polyphenols; D013662:Tea; D016264:Dextran Sulfate; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase