Neuropharmacological activity of the aqueous leaf extract of Croton zambesicus (euphorbiaceae) in some laboratory animals

&nbsp;To determine the neuropharmacological activity of the leaf extract of Croton zambesicus in mice and chicks.&nbsp;The effect of aqueous leaf extract of Croton zambesicus on thiopental sodium &ndash; induced sleeping time in mice, on gross locomotor activity (GLA) in 2-day old chicks and effect of extract on apomorphine - induced stereotyped behavior in chicks were evaluated.&nbsp;The aqueous extract (1000 and 1500 mg/kg), administered per os (p.o), prolonged the thiopental sodium - induced sleeping time in mice. &nbsp; Extract (20-40 mg/kg i.p) produced a significant ( P < 0.05) decrease in GLA in 2-day old chicks in a dose dependent manner. 40-60 mg/kg administered intraperitoneally (i.p) produced sedation and sleep with a significant ( P < 0.05) decrease in onset and an increase in duration of sleep. The extract had an insignificant (P > 0.05) effect on apomorphine - induced stereotyped behavior in chicks.&nbsp; &nbsp; These results suggest that leaf extract of Croton zambesicus possesses CNS depressant, sedative, and hypnotic activity.