Ameliorative effects of hydromethanolic extract of Citrullus lanatus (watermelon) rind on semen parameters, reproductive hormones and testicular oxidative status following nicotine administration in male Wistar rats

Abstract

Summary: The present study examines the possible ameliorative effects of the hydromethanolic extract of Citrullus lanatus rind (HECL) on some reproductive function and oxidative indices of the testes in male Wistar rats following administration of nicotine. Twenty male rats were assigned into four groups: Group A to D of five rats each. Group A served as control and received 2ml/kg body weight of 10% extract vehicle; Group B received 1mg/kg body weight of nicotine; Group C were co-administered 1mg/kg body weight nicotine and 500 mg/kg body weight of HECL and Group D received only 500mg/kg body weight of HECL. The drugs and extracts were administered orally to the rats for 42days; blood samples were collected by direct cardiac puncture for determination of serum concentrations of testosterone, Follicle Stimulating Hormone and Luteinizing Hormone. The testes were also harvested for determination of semen parameters: motility, morphology, viability and count and testicular tissue processed for superoxide dismutase and malondialdehyde concentration. Compared to Group A control rats, administration of HECL significantly increased sperm count and reproductive hormone concentrations amongst Group B rats (p<0.05). Treatment with nicotine caused a significant reduction in the levels of all reproductive hormones with significant diminution of some sperm parameters: motility, morphology and viability; and decrease in superoxide dismutase and increase in malondialdehyde concentration amongst Group B rats compared to Group A control rats (p<0.05). Co-administration of HECL with nicotine to Group C rats apparently reversed the effects of nicotine resulting in significant increases in sperm count and the reproductive hormones concentration as compared to Group A control rats (p<0.05). Amongst Group D rats, the extract also caused a significant increase in superoxide dismutase concentration and a significant decrease in malondialdehyde concentration compared with the Group A control rats (p<0.05). The findings suggest that the hydromethanolic extract of Citrullus lanatus rind possibly ameliorates the deleterious effects of nicotine on some reproductive indices in male Wistar rats.

Keywords: Citrullus lanatus; nicotine, superoxide dismutase, lipid peroxidation, semen; reproductive hormones