Pu-erh black tea extract supplementation attenuates the oxidative DNA damage and oxidative stress in Sprague-Dawley rats with renal dysfunction induced by subchronic 3-methyl-2-quinoxalin benzenevinylketo-1,4-dioxide exposure.

3-Methyl-2-quinoxalin benzenevinylketo-1,4-dioxide (Quinocetone, QCT), has been used to treat dysentery and promote growth in animal feeding. However, available data show that QCT has potential nephrotoxicity. The present study was designed to investigate the protective effects of Pu-erh black tea extract (PBTE) which is a traditional remedy in China with antioxidant properties against oxidative DNA damage and oxidative stress in a rat model of QCT-induced renal dysfunction. Increased serum creatinine, blood urea nitrogen, pathological lesions, urinary 8-hydroxy 2-deoxyguanosine (8-OHdG) and renal DNA damage were observed in the QCT-fed rats. These were accompanied by intracellular reactive oxygen species accumulation, enhanced lipid peroxidation, and inhibited antioxidant system, i.e., glutathione glutathione S-transferase, glutathione peroxidase and glutathione reductase. Oral administration of PBTE effectively suppressed QCT-induced renal dysfunction, as evidenced by reduced serum creatinine, urinary 8-OHdG and DNA damage in isolated renal cells, amelioration of oxidative stress and modulation of antioxidative system. In conclusion, PBTE administration ameliorated QCT-induced nephrotoxicity by maintaining DNA's double-helix architecture and mitigating oxidative stress.