Green Tea Polyphenols Attenuate High-Fat Diet-Induced Renal Oxidative Stress through SIRT3-Dependent Deacetylation

Fifty male Wistar rats were fed a standard chow diet or a high-fat (HF) diet, and different concentrations of green tea polyphenols (GTPs) (0.8, 1.6, and 3.2 g/L) were administered in the drinking water. We found that the malondialdehyde (MDA) level in the HF diet group was significantly higher than that in the control (CON) group (P<0.05). Decreased peroxisome proliferator-activated receptor (PPAR)-alpha and sirtuin 3 (SIRT3) expression, and increased manganese superoxide dismutase (MnSOD) acetylation levels were also detected in the HF diet group (P<0.05). GTP treatment upregulated SIRT3 and PPAR alpha expression, increased the ppar alpha mRNA level, reduced the MnSOD acetylation level, and decreased MDA production in rats fed a HF diet (P<0.05). No significant differences in total renal MnSOD and PPAR-gamma coactivator-1 alpha (PGC1-alpha) expression were detected. The reduced oxidative stress detected in kidney tissues after GTP treatment was partly due to the higher SIRT3 expression, which was likely mediated by PPAR alpha.