Behavioural effect of Pavetta crassipes extract on rodents

The effects of the ethanol extract of Pavetta crassipes on the central nervous system (CNS) and on actions of some selected centrally acting drugs were studied in mice and rats. These studies were carried out using the spontaneous motor activity (SMA), amphetamine-induced hyperactivity and stereotyped behaviour, pentobarbital-induced hypnosis and exploratory activity, apomorphine-induced climbing and haloperidol-induced catalepsy in rats. The results demonstrated that the extract of P. crassipes dose-dependently decreased SMA in mice and attenuated amphetamine-induced hyperactivity and the different episodes of stereotypic behavioural patterns induced by amphetamine. In addition. the extract decreased the number of head dips in the exploratory activity test and potentiated pentobarbital-induced sleeping time in rats. Furthermore, the extract inhibited apomorphine-induced climbing in mice and potentiated haloperidol-induced catalepsy in rats. Our results suggest that the extract of P. crassipes contains biologically active substance(s) that might be acting centrally through the inhibition of dopaminergic pathway or a system linked to this pathway to mediate the observed pharmacological effects. (C) 2004 Elsevier Inc. All rights reserved.