The Influence of Garcinia kola Seed on Sexual Behavior and Testis Physiology in Wistar Rats

Garcina kola seed is believed by some to enhance male sexual performance but existing scientific data show divergent results. In this study, the sexual and reproductive influence of ethanol (70%) seed extract of G. kola was evaluated in Wistar rats. Adult male rats were gavaged with 0, 50, 100, 200 or 300 mg kg^-1 day^-1 of extract for 30 days and mated with female rats after sexual behavior characteristics were carefully evaluated. Serum concentrations of testosterone, LH and FSH, as well as epididymal sperm indices were analyzed after mating, while pregnancy rate and litter size of female rats were recorded. Extract (50 mg kg^-1) treatment produced no effect on sexual activities, but higher doses caused reduction relative to control. Additionally, except at 50 mg kg^-1, extract treatment caused reduction in sperm count (p<0.0001), sperm viability (p = 0.0011), testosterone and FSH (p<0.0001). LH was unaltered, while abnormal sperm morphology was elevated (p<0.05). Furthermore, pregnancy rate and litter size in extract (100-300 mg kg^-1) treated rats were lower when compared to control. The results suggest that low dose of G. kola seed may not affect sexual activity, whereas high doses may affect fertility by negatively altering sexual behavior, testosterone level and sperm indices.