Melatonin mitigates dichlorvos-induced derangements in the testes and epididymis of male Wistar rats

Ajani, Olumide SamuelSamuel, Ekundayo Stephen

Abstract Dichlorvos (DDVP) is a widely used organophosphate insecticide. The reports of its toxicity and induction of oxidative stress have warranted the search for an antidote. Melatonin (MLT), a hormone found naturally in the body is known to mitigate oxidative stress. Therefore, the present study aimed to investigate the protective effects of melatonin on dichlorvos-induced toxicity in the testes and epididymis. Sixty (60) 10 weeks of male Wistar rats (160 ± 10g) randomly grouped into four (n=15, A-D) were used and treated as follows: A (Control): corn oil (1 mL/kg body weight), B: MLT (10 mg/kg), C: DDVP (1.6 mg/kg), and D: DDVP and MLT. Except for the MLT intra-peritoneal treatment, other test samples were administered orally for 45 days. Histomorphometry and histological examinations were conducted on the testes and epididymis 24h, 14 days, and 45 days after treatment. There was a significant decrease in the epithelial length of the epididymis of rats treated with DDVP at 24h and 45 days post-treatment compared to the control. MLT significantly increase the mean epididymal epithelial length at 24h and 45 days post-treatment in the co-treated group. The DDVP-induced significant reduction in the testes' luminal diameter was reversed by MLT in the co-treated group. MLT, DDVP (45th-day treatment), and DDVP+MLT (14th and 45th-day treatment) increased the epididymal luminal diameters significantly compared to the control. Meanwhile, DDVP altered both the testicular and epithelial architectures and caused atrophy of the seminiferous tubules and spermatogenic arrest with atrophy of epithelial tubules, especially following 14- and 45-day treatment. These lesions were reversed in the co-exposed rats by MLT. In conclusion, melatonin mitigates the derangements induced by dichlorvos in the testes and epididymis.