Effects of Vernonia amygdalina Del. (Asteraceae) on Glycemia and Mating Behavior of Male Albino Rats

Aims: To determine the effect of oral administration of Vernonia amygdalina ethanolic leaves extracts on blood glucose concentration of alloxan-induced hyperglycemic albino rats and the effect of the extract on the mating behavior of male albino rats.

Study Design and Methodology: Normoglycemic and alloxan-induced hyperglycemic rats divided into 6 groups of 6 rats each were treated with 400 mg/kg of 70% ethanolic leaves extracts, chlorpropamide 50 mg/kg and distilled water 10 ml/kg respectively once daily for 14 days. The blood glucose concentration and weight were monitored. Oral glucose tolerance test was carried out using another set of rats according to the same grouping. Another set of rats were pretreated with the extract for 7 days and then challenged with alloxan. Sexual function parameters of mount, intromission and ejaculation were evaluated in a fourth set of rats which were administered with 100, 200 and 400 mg/kg of the extract. Rats treated with 5 mg/kg sildenafil citrate and 10 ml/kg distilled water served as the positive and negative controls respectively.

Results: The results obtained showed that the extract significantly reduced blood glucose concentration of alloxan-induced hyperglycemic rats and also improved glucose tolerance. However, in rats pretreated with 400 mg/kg extract for 7 days and then challenged with alloxan, there was a significant increase in blood glucose concentration. No significant changes were observed in the sexual function parameters of rats treated with the extract.

Conclusion: The 70% ethanolic leaves extract of Vernonia amygdalina possesses blood glucose lowering activity in alloxan-induced hyperglycemia and also improves glucose tolerance. However, it did not have aphrodisiac activity at the tested doses and duration of treatment.