Evaluation of Blood Oxidant/Antioxidant Changes and Testicular Toxicity after Subacute Exposure to Cadmium in Albino Rats: Therapeutic Effect of Nigella sativa Seed Extracts

Aim and Objective: Cells and tissues of the body are prone to oxidative damage as a result of an increased level of reactive oxygen species and nitrogen radical beyond the detoxifying ability of the endogenous antioxidant system. This study aimed to evaluate the ameliorative effect of methanolic extracts of Nigella sativa (MENS) against cadmium-induced blood oxidative stress and testicular toxicity in albino rats. Materials and Methods: Twenty-five (25) male albino rats, weighing (200 ± 20g), were randomly grouped into five groups (A-E). Group B (Negative Control) received intraperitoneal administration of cadmium chloride (CdCl2, 5 mg/kg) only, group C received CdCl2 and low dose MENS (300 mg/kg, oral), group D received CdCl2 and high dose MENS (600 mg/kg, oral), group E (Positive control) received CdCl2 and Vitamin C (200 mg/kg, oral), for 14 days. No treatment was administered to group A (Normal control). The oxidative state of the blood was assessed by measuring the blood levels or activities of MDA, CAT, GSH and SOD; while testicular injury was assessed by measuring serum testosterone level using ELISA. The testes were harvested for histopathological examination. Results: The results showed that cadmium induced a marked elevation in the level of MDA, and a decrease in SOD, CAT and GSH levels or activities (p<0.05 or p<0.01); but no significant alteration in the serum testosterone level was found (p>0.05); Histopathological studies on the testes showed that cadmium significantly induced testicular injury, which was however ameliorated by the seed extract of N. sativa. Conclusion: We conclude that N. sativa seed extract is potentially testiculoprotective and attenuates oxidative stress against harmful chemical toxins such as cadmium.