In/ex copula ejaculatory activities of aqueous and methanolic extracts of Aframomum melegueta (Zingiberaceae) in sexually experienced male rat.

This study was undertaken to evaluate the effects of Aframomum melegueta on male rat ejaculation using in/ex copula techniques. For the in copula experiment, rats were orally treated with aqueous or methanolic extract (20 and 100 mg/kg) of A. melegueta for 14 days. Each rat was mated with a primed receptive female on days 0, 7 and 14 of treatment, and the ejaculatory latency and post-ejaculatory interval were measured. In the ex copula experiment, the electromyography of the bulbospongiosus muscles and intraseminal pressure were recorded in spinal rats after mechanical (urethral and penile) and pharmacological stimulations (intravenous injection of dopamine (5 mg/kg) and, aqueous or methanolic extract of A. melegueta, 2.5; 5; 10 and 20 mg/kg). Furthermore, the effect of dopamine on fictive ejaculation was monitored in rats orally pre-treated with A. melegueta extracts (20 and 100 mg/kg) for 7 or 14 days. Treatment with the aqueous or methanolic extract of A. melegueta significantly decreased the ejaculatory latency (p < .05) and post-ejaculatory interval (p < .01) after 14 days. In spinal rats, mechanical or pharmacological stimulations triggered fictive ejaculation. In animals orally pre-treated with A. melegueta extracts, the pro-ejaculatory effect of dopamine was more expressed. Present findings show that A. melegueta possesses pro-ejaculatory effects.