Abstract

Cadmium (Cd) is a well-known human carcinogen and a potent nephrotoxin. Curcumin, the yellow bioactive component of turmeric has established its antioxidant activities. The aim of this study was to investigate the protective role of curcumin against Cd induced nephrotoxicity. The rats were treated once daily by oral gavage for five days and divided into four groups of 8 rats each: control, Cd acetate 200 mg/kg BW, curcumin 250 mg/kg BW and pre-treatment with curcumin 250 mg/kg BW for one hour before administration with Cd acetate 200 mg/kg BW. After 24 h of the last treatment, we examined the level of lipid peroxidation (measured as malondialdehyde, MDA), reduced glutathione (GSH) and histological changes at the light microscopic level in renal tissues. The results showed that Cd treatment increased significantly renal lipid peroxidation (p < 0.01), which was associated with increased significantly reduced GSH levels (p < 0.01). In addition, the hydropic swelling and hypertrophy of proximal tubular cells in renal cortex was also observed by Cd treatment. The pretreatment with curcumin led to an improvement in both biochemical and histological alterations induced by Cd. A slight but not significant reduction of MDA content in renal tissue was observed in curcumin pretreated rats as compared with the Cd treated group. Interestingly, the reduced GSH levels was significantly reduced (p < 0.01) in curcumin pretreated rats when compared with those of Cd-treated group. In parallel, the administration of curcumin to Cd treated rats resulted in the improvement of proximal tubular cells. These results were indicated that Cd caused renal toxicity by inducing lipid peroxidation and morphological alterations. In conclusion, these results suggest that curcumin partially protect against Cd-induced nephrotoxicity. This study could be important for the further understanding of Cd toxicity in renal tissues and in the development of better treatments for people and/or animals exposed to the heavy metal.

Key words: Curcumin, cadmium, nephrotoxicity, histology of kidney, MDA, reduced glutathione.