Abstract

The neuropharmacological effects of aqueous methanolic extract of leaf base ofSorghum bicolor were studied on Wistar rats and Swiss albino mice; evaluations were done on spontaneous motor activity, exploratory behaviour, apomorphine-induced stereotypic behaviour, pentobarbitone sleeping time and rota-rod performance for motor coordination. The results showed a significant (P < 0.05) reduction in the spontaneous motor activity. The treated animals exhibited: (i) A reduction in the exploratory behaviour as did diazepam (1 mg/kg i.p.); (ii) No change in Apomorphine-induced stereotypic behaviour; (iii) Prolonged pentobarbitone-induced sleep as did diazepam (1 mg/kg i.p.) and cimetidine (100 mg/kg p.o) and no significant (P < 0.05) effect on rota-rod performance for motor coordination. These findings suggest that leaf base extracts of S. bicolor contains sedative substances that act via centrally-mediated actions rather than peripheral neuromuscular blockade and may also be microsomal enzyme inhibitor like cimetidine.

Key words: Sorghum bicolor, spontaneous motor activity, exploratory behaviour, stereotype behaviour, pentobarbitone sleep, motor coordination.