Nigella sativa Seed Protects Against Cadmium-induced Renal Toxicity in Rats

Background: Prevalence of chemical-induced renal injuries has been on a fast rise over the years and has become the leading cause of mortality and morbidity in the society, with environmental pollutants, heavy metals inclusive, seen as the causal agents. Recently, the role of medicinal foods in human health has gained considerable attention. Objective: We investigated the protective effects of methanolic extract of Nigella sativa (MENS) (Black seed) against cadmium-induced renal toxicity in albino rats. Methods: Twenty-five (25) male albino rats, weighing (150-170g), were randomly grouped into five groups: A-E. Group B (Negative Control) received intraperitoneal administration of cadmium chloride (CdCl2, 5mg/kg) only, group C received CdCl2 and low dose MENS (300mg/kg, oral), group D received CdCl2 and high dose MENS (600mg/kg, oral), group E (Positive control) received CdCl2 and Vitamin C (200mg/kg, oral), for 7 days. No treatment was administered to group A (Normal control). Renal injury was assessed by measuring serum levels of Na+, K+, creatinine and blood urea nitrogen (BUN) using standard methods. The kidneys were harvested for histopathological examination. Results: CdCl2 induced significant nephrotoxicity with marked elevation in the levels of biochemical markers of renal functions (p<0.05 or p<0.01); these were, however, ameliorated by a low dose of MENS. Histopathological examination of the kidney sections supported the biochemical findings. Conclusion: We conclude that Nigella sativa seed extract, at a low dose, is potentially nephroprotective against harmful chemical toxins such as cadmium.