Evaluation of Male Fertility-Enhancing Activities of Water Seed Extract of Hunteria umbellata in Wistar Rats

BACKGROUND: In this study, the male fertility-enhancing activity of 100, 200, and 400 mg/kg/day of Hunteria umbellata water seed extract (HU) in Wistar rats was studied for 60 days. In doing this, effect of repeated doses of HU was studied on the weight gain pattern, gonadosomatic index (GSI), serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone (TS), prolactin (PRL), and estradiol (ES)} as well as testicular antioxidant status of the treated rats as a way of elucidating the mechanism(s) of action of HU. METHOD: Thirty-six (36) male Wistar rats were randomly divided into six groups (I-VI) of six rats per group. Group I rats were gavaged with 10 ml/kg/day of distilled water and served as an untreated control; Group II rats were gavaged with 0.3 mg/kg/day of clomiphene in distilled water; Groups III-V rats received 100 mg/kg/day, 200 mg/kg/day, and 400 mg/kg/day of HU, respectively, and Group VI rats received 20 mg/kg/day of Vitamin C all in distilled water. All treatments were for 60 days after which the treated rats were humanely sacrificed. Sera of blood samples were processed for the above stated hormonal profile. Similarly, testicular tissues obtained were processed for semen analysis and complete antioxidant profile of the HU-treated testicles by assaying for superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH), glutathione reductase (GSR), glutathione peroxidase (GSH-Px), and Thiobarbituric Reactive Species (TBARS). RESULTS: Prolonged treatments with 100 mg/kg/day, 200 mg/kg/day, and 400 mg/kg/day of HU for 60 days induced dose dependent reductions in weight gain pattern with the most significant (p<0.001) effect recorded with the highest dose of HU. Conversely, significant (p<0.001) increase was recorded for GSI at the same HU dose. Clomiphene and HU also induced significant (p<0.01, p<0.001) dose dependent increases in the total sperm count, %live sperm, but reverse effects on %dead sperm and %abnormal sperm. On the hormonal profile, oral treatment with 100 mg/kg/day, 200 mg/kg/day, and 400 mg/kg/day of the extract induced profound (p<0.05, p<0.01, and p<0.001) dose related increases in the sera TS, LH, and FSH while it caused reverse effect on serum PRL but caused no significant alterations in the serum ES levels. Similarly, oral treatment with vitamin C and 100-400 mg/kg/day of HU induced profound (p<0.05, p<0.01, and p<0.001) increases in the antioxidant enzyme activities. CONCLUSION: Overall, prolonged oral treatment with 100-400 mg/kg body weight of HU for 60 days significantly improved sperm function which was mediated via enhanced spermatogenesis, steroidogenesis, and antioxidant mechanisms.