Pathological, biochemical and hormonal changes associated with prolonged administration of methanol extract of <i>Garcinia kola</i> seed in adult male Wistar rats.

Garcinia kola (GK) seed is believed to possess aphrodisiac properties hence its traditional use to manage erectile dysfunctions in man. However, there has been conflicting reports of its long-term effects on the male reproductive organs. In this study, the effect of varying doses of methanol extract of GK on testicular function and structure in Wistar rats was evaluated. Forty adult male rats (350-360g) were randomly divided into 4 groups. Groups 1, 2 and 3 received oral doses of 600mg/kg, 400mg/kg and 100mg/kg of the extract daily, respectively for 70 days while group 4 (control group) received normal saline (0.9% NaCl). Blood samples were collected fortnightly from each rat for serum chemistry and testosterone analysis. At termination, the testes, epididymides and livers were harvested, weighed and fixed in 10% neutral buffered formalin and processed for histopathology. The results were presented as mean ± standard error of mean (SEM) and analyzed using one way analysis of variance (ANOVA) at P< 0.05. Dose-related pathological changes were observed in the testes and epididymides. Testicular weight decreased significantly (p<0.05) in 400mg/kg and 600mg/kg groups compared to the control group. There was testicular necrosis associated with distortion of the seminiferous tubular wall and reduced seminiferous tubular diameter. Seminiferous tubules had reduced germinal epithelial thickness along with an absence of viable spermatids and spermatozoa. Serum testosterone levels decreased progressively (p < 0.01) in groups 1 and 2 while those of groups 3 and 4 remain unchanged. The results established that ingestion of methanol extracts of GK seed at the dose of 400mg/kg and 600mg/kg produced significant gonadal pathology in adult male Wistar rats despite the absence of remarkable hepatic biochemical and structural changes.