Evaluation of the Biochemical Effects of Ethanolic Extract of Cola Nitida (Kola Nut) on Female Reproductive Hormones in Albino Rats

Abstract

The Kola nut (Cola nitida) is commonly used in West Africa due to its stimulant characteristics and cultural importance; yet, its possible effects on female reproductive endocrine function are poorly understood. This study investigated the biochemical effects of ethanolic extract of Cola nitida on selected reproductive hormones in female albino rats. Experimental study design was utilised. Female albino rats were randomly assigned into three groups. Group I was the control and was given distilled water and normal rat meal. Group II and III were given normal rat feed and distilled water supplemented with the ethanolic C. nitida extract at 100 and 400 mg/kg body weight respectively for 28 days. At the end of the therapy period blood samples were taken and sera were separated for hormonal analysis. Serum concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin and progesterone were measured by enzyme linked immunosorbent assay (ELISA). Data were represented as mean ± standard deviation and analysed using one-way analysis of variance (ANOVA) followed by Tukey’s post hoc test and significance was established at p < 0.05. The results demonstrated significant changes in the concentrations of all the studied hormones. The FSH concentration was lowered from 5.15 ± 0.13 mIU/mL in control group to 4.78 ± 0.15 mIU/mL in high dosage group (p = 0.015). Likewise, there were substantial reductions in prolactin and LH concentrations in all therapy groups (p = 0.001 and 0.004, respectively). However, the progesterone concentration was considerably enhanced from 1.60 ± 0.08 ng/mL in the control group to 2.43 ± 0.15 ng/mL in the high-dose group (p < 0.001). These results demonstrate that the ethanolic C. nitida extract altered the reproductive hormonal profile of female albino rats, characterised by decrease in FSH, LH and prolactin and increase in progesterone. The modifications observed, particularly at higher doses, indicate that long-term use of C. nitida may impact on the hypothalamic–pituitary–ovarian axis and subsequently alter the female reproductive endocrine function.