Ameliorative effects of curcumin against renal injuries mediated by inducible nitric oxide synthase and nuclear factor kappa B during gentamicin-induced toxicity in Wistar rats

The ameliorative role of curcumin in attenuating gentamicin-induced nephrotoxicity has been reported earlier however, the mechanism of action remains unclear. Gentamicin was injected intraperitoneally (100 mg/kg body weight) once daily for 6 days. Curcumin was administered orally (200 mg/kg body weight) once daily for 7, 15 and 30 days. Gentamicin-induced rats showed significant increase in the levels of kidney markers and the activities of urinary marker enzymes, which was reversed upon curcumin treatment. A significant increase in kidney lipid peroxidation (LPO) and decrease in activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) were observed in gentamicin-induced rats. Immunohistochemical, Western blot and RT-PCR studies in gentamicin-induced rats also demonstrated an increase in the levels of inducible nitric oxide synthase (iNOS) and nuclear factor-κB (NF-κB). All these effects induced by gentamicin were reduced upon treatment with curcumin in a time dependent manner. To conclude, curcumin enhances antioxidants, and decreases iNOS and NF-κB, thereby protecting the cells against oxidative stress induced by gentamicin.