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. Nontreated 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.

Antioxidant fractions of Khaya grandifoliola C.DC. and Entada africana Guill. et Perr. induce nuclear translocation of Nrf2 in HC-04 cells

“…In fact, production of H 2 O 2 by polyphenols in culture media has been previously demonstrated (Long et al 2000;Erlank et al 2011). In the same line, high-dose green tea polyphenols was reported to be nephrotoxic in mice (Inoue et al 2011).…”

Chemoprevention Against Arsenic-Induced Mutagenic DNA Breakage and Apoptotic Liver Damage in Rat Via Antioxidant and SOD1 Upregulation by Green Tea (Camellia sinensis) which Recovers Broken DNA Resulted from Arsenic-H2O2Related in Vitro Oxidant Stress

“…The remaining group (I) designated as control was supplied with same amount of drinking water for stipulated duration. Group-III animals were supplemented with lyophilized 1 ml extract of CS by gavages at a concentration of 10 mg/ml/100 g body weight/day for 28 days [17]. On day 29, animals were exposed to light anesthesia (by ether), and blood was collected using a disposable syringe (21-gauge needle), serum was separated from the collected blood samples.…”

Low and Medium but Not High Doses of Green Tea Polyphenols Ameliorated Dextran Sodium Sulfate-Induced Hepatotoxicity and Nephrotoxicity

“…PCR was done using a thermal cycler (PTC-0100; MJ Research, Cambridge, MA) with mouse hypoxanthine phosphoribosyl transferase (HPRT), HO-1, HSP70, and HSP90 primers. 19) The PCR products were subjected to electrophoresis in 3% agarose gels and were stained with 0.01% SYBR Gold stain (Molecular Probes, Eugene, OR). Band intensities were quantified by NIH image, and an absence of PCR saturation was confirmed.…”

“…18) Furthermore, a 1% GTPs diet exacerbated kidney and liver functioning, presumably through downregulation of antioxidant enzymes and HSPs, in both normal mice and ones with DSS-induced colitis. 19) Lambert et al found that EGCG at 1% induced hepatotoxicity, as demonstrated by increased formation of malonyldialdehyde and 4-hydroxynonenal. 20) In addition, several cases of hepatotoxicity in humans following the consumption of dietary supplements containing green tea extracts have been reported.…”