Vitamin E Mitigates Chronic Chlorpyrifos-Induced Oxidative Changes in Pituitary Glands and Testes in Wistar Rats

Problem statement: The sperm counts of men have declined by about 50% in the last few decades. The contribution of environmental contaminants to this decline cannot be overemphasized. Pesticide is one of the most pervasive environmental chemical contaminants that have been of increased use due to the compelling need to feed the ever-growing world human and animal population and protect their health. Chlorpyrifos (CPF), a widely used Organophosphate (OP) insecticide has been reported to alter male reproductive hormones and semen characteristics. Apart from acetyl cholinesterase inhibition, the induction of oxidative stress is one of the molecular mechanisms implicated in CPF poisoning. Approach: The present study was aimed at evaluating the effect of vitamin E in mitigating oxidative damage to the pituitary gland and the testis, induced by chronic CPF administration in Wistar rats. Methodology: Twenty adult male Wistar rats divided into 4 groups of 5 rats in each group were used for this study. Group I received soya oil (2 mL kg^-1), while Group II was administered vitamin E (75 mg kg^-1); Group III was administered CPF only (10.6 mg kg^-1~1/8th LD₅₀), while group IV was pretreated with vitamin E (75 mg kg^-1) and exposed to CPF (10.6 mg kg^-1) 30 min later. The regimens were administered orally by gavages once daily for a period of 15 weeks. At the end of the treatment period, the rats were sacrificed and the pituitary glands and testicular tissues were assayed for the concentrations of Malonaldehyde (MDA) and the activities of Superoxide Dismutase (SOD) and Catalane (CAT). Results: The result showed that the increase in concentrations of pituitary and testicular MDA and a decrease in the activities of SOD and CAT recorded in the group exposed to CPF were ameliorated by pretreatment with vitamin E. Conclusion: This indicates that vitamin E mitigates reproductive toxicity induced by chronic CPF exposure due to its protective antioxidant activity on pituitary glands and the testes.