Fertility Evaluation of Adult Female Wistar Rats Administered with Ethanolic Extract of Pausinystalia yohimbe Stem Bark

Pausinystalia yohimbe (P. yohimbe) stem bark powder is commonly used as seasoning for barbecue beef in Nigeria and some West African countries. This study evaluated the effect of ingesting ethanol extract of P. yohimbe stem bark on some hormones and tissues linked with fertility in female Wistar rats. A total of fifteen adult female Wistar rats weighing between 140 - 160g were used for this study after an initial Acute Toxicity test was done to establish a safe dose range of the extract. The animals were randomly divided into three groups of five rats per group. Group 1 served as control and received normal saline while Groups 2 and 3 received 400 mg/kg and 800 mg/kg body weight (bw) of ethanol extract of P. yohimbe stem bark respectively, via oral gavage, for 21 days. At the end of the treatment period, the rats were weighed, sacrificed and blood, ovary and uterus samples collected for determination of reproductive hormones (follicle-stimulating hormone, estrogen, and progesterone) and histological examination using standard methods. The results showed that LD50 of the ethanol extract for the female Wistar rats was 3807.89 mg/kg bw. There were significant (p˂0.05) increases in body weight, estrogen and follicle-stimulating hormone (FSH) of the treated groups compared with the control. Histological examination also showed degenerative changes in the uterus of the rats in groups 2 and 3, with no alterations in the ovary when compared to control. These results suggest that continuous consumption of ethanol extract of P. yohimbe stem bark may alter the systemic concentration of estrogen and follicle-stimulating hormone as well as morphology of the uterus which may lead to reduced reproductive function and female infertility.