Comparative in vitro and in vivo aphrodisiac activities of Khaya grandifoliola C. DC. (Meliaceae) stem bark in male rat model

Abstract

Khaya grandifoliola C. DC. (Meliaceae), is a large tree exploited for timber purpose, for treating various illnesses and to enhance libido in Nigerian indigenous traditional medicine. Therefore, this study evaluates the aphrodisiac potential of K. grandifoliola stem bark in male Wistar rats. Aphrodisiac potential was determined following the oral administration of graded doses: 250, 500 and 1000 mg/kg of crude MeOH extract of K. grandifoliola stem bark, and 100 and 200 mg/kg each of aqueous (AQ) and dichloromethane (DCM) fractions. Sildenafil citrate and distilled water served as positive and negative controls, respectively. Sexual behavioural parameters like mount, intromission and ejaculatory frequencies and latencies were recorded on day 7. Serum testosterone concentrations and haematological parameters were also monitored. The findings from the sexual behavioural study indicated that methanol extract of K. grandifoliola was active and significantly increased mount and intromission frequencies, and intromission and mount latencies in a dose- dependent manner, but had no effect on ejaculatory frequency and ejaculatory latency. Both AQ and DCM fractions were more active than the extract but comparable to Sildenafil citrate, with the DCM fraction being comparatively more active. Testosterone concentrations were also increased dose-dependently by all tested agents, but DCM fraction was the most active and comparable to Sildenafil citrate. Improvement in some haematological indices, HB and PCV was evident with DCM fraction. From all indications, methanol extract of K. grandifoliola stem bark which increased serum testosterone and sexual behavioural indices has potential for improving sexual dysfunction in males, and the more active DCM fraction qualifies for further phytochemical investigation to isolate active compounds. These findings therefore justify the acclaimed local use of K. grandifoliola stem bark as an aphrodisiac in males.