Sedative and hypnotic effects of the roots of Asparagus africanus (Asparagaceae) decoction on white mice (Mus musculus Swiss)

Asparagus africanus Lam. (Asparagaceae) is a plant widely used in traditional medicine as an anti-inflammatory, for the treatment of nervous disorders and insomnia. The aim of this work was to study the sedative and hypnotic effects of the roots of A. africanus decoction on white mice (Mus musculus Swiss). Sleep potentiation tests induced by diazepam and sodium pentobarbital were used. The sleep latency period onset and the sleep duration were recorded. The concentrations of GABA a[nd GABA-T in the brains of mice were also estimated. A. africanus significantly decreased the sleep latency period onset and increased the sleep duration induced by diazepam and sodium pentobarbital. Bicuculline, a competitive photosensitive antagonist of the GABAA receptor complex, did not prevent this potentiation. The effect of A. africanus on the sleep time was not blocked by flumazenil, a specific antagonist to the benzodiazepine site in the GABAA receptor complex. GABA increased and GABA-T decreased in the animals brain A. africanus treated significantly. Therefore the sedative properties of A. africanus might be possibly mediated by the activation of GABAergic neurotransmission on inhibitory receptors and by the decrease in the recapture of GABA by inhibiting GABA-T. These properties justified its use against insomnia in traditional medicine.