Nigella sativa (black cumin) ameliorates potassium bromate-induced early events of carcinogenesis: diminution of oxidative stress

Abstract

Potassium bromate (KBrO3) is a potent nephrotoxic agent. In this paper, we report the chemopreventive effect ofNigella sativa (black cumin) on KBrO3-mediated renal oxidative stress, toxicity and tumor promotion response in rats. KBrO3 (125 mg/kg body weight, intraperitoneally) enhances lipid peroxidation, g-glutamyl transpeptidase, hydrogen peroxide and xanthine oxidase with reduction in the activities of renal antioxidant enzymes and renal glutathione content. A marked increase in blood urea nitrogen and serum creatinine has also been observed. KBrO3 treatment also enhances ornithine decarboxylase (ODC) activity and [3H] thymidine incorporation into renal DNA. Prophylaxis of rats orally with Nigella sativaextract (50 mg/kg body weight and 100 mg/kg body weight) resulted in a significant decrease in renal microsomal lipid peroxidation (P B-00.001), g-glutamyl transpeptidase (P B-0.001), H2O2 (P B-0.001) and xanthine oxidase (P B-0.05). There was significant recovery of renal glutathione content (P B-0.01) and antioxidant enzymes (P B-0.001). There was also reversal in the enhancement of blood urea nitrogen, serum creatinine, renal ODC activity and DNA synthesis (P B-0.001). Data suggest that Nigella sativa is a potent chemopreventive agent and may suppress KBrO3-mediated renal oxidative stress, toxicity and tumour promotion response in rats.