Tephrosia purpurea ameliorates N-diethylnitrosamine and potassium bromate-mediated renal oxidative stress and toxicity in Wistar rats

In an earlier communication, we have shown that Tephrosia purpurea ameliora tes benzoyl peroxide-induced oxidative stress in murine skin (Saleem et al. 1999). The present study was designed to investigate a chemopreventive eff icacy of T. purpurea against N-diethylnitrosamine-initiated and potassium b romate-mediated oxidative stress and toxicity in rat kidney. A single intra peritoneal dose of N-diethylnitrosamine (200 mg/kg body weight) one hr prio r to the dose of KBrO3 (125 mg/kg body weight) increases microsomal lipid p eroxidation and the activity of xanthine oxidase and decreases the activiti es of renal antioxidant enzymes viz., catalase, glutathione peroxidase, glu tathione reductase and glucose-6-phosphate dehydrogenase, phase II metaboli zing enzymes such as glutathione-S-transferase and quinone reductase and ca uses depletion in the level of renal glutathione content. A sharp increase in blood urea nitrogen and serum creatinine has also been observed. Prophyl actic treatment of rats with T. purpurea at doses of 5 mg/kg body weight an d 10 mg/kg body weight prevented N-diethylnitrosamine-initiated and KBrO3 p romoted renal oxidative stress and toxicity. The susceptibility of renal mi crosomal membrane for iron ascorbate-induced lipid peroxidation and xanthin e oxidase activities were significantly reduced (P<0.01). The depleted leve ls of glutathione, the inhibited activities of antioxidant enzymes, phase I I metabolizing enzymes and the enhanced levels of serum creatinine and bloo d urea nitrogen were recovered to a significant level(P<0.01). All the anti oxidant enzymes were recovered dose-dependently. Our data indicate that T. purpurea besides a skin antioxidant can be a potent chemopreventive agent a gainst renal oxidative stress and carcinogenesis induced by N-diethylnitros amine and KBrO3.