BEHAVIOURAL AND ANTICONVULSANT EFFECTS OF METHANOL EXTRACT OF FICUS VALLIS CHOUDAE (MORACEAE) STEM BARK

ABSTRACT

Ficus vallis choudae is a plant widely spread in tropical Africa including Nigeria. It is said to be of value in ethnomedicine especially in the treatment of jaundice, gastrointestinal problems, giddiness and epilepsy. The anticonvulsant activity of methanol stem bark extract of Ficus vallis was studied in mice and two-day old cockrels. This study was conducted using three models; pentylenetetrazole-induced seizure test, maximal electroshock seizure test and 4-aminopyridine-induced seizure test. Also, the sedative as well as motor coordination deficit effects were studied in mice; using diazepam-induced sleep, hole-board test, and walking beam assay models respectively. The extract afforded 25.0%, 50.0% and 33.3% protections at doses of 80mg/kg, 40mg/kg and 20mg/kg respectively against pentylenetetrazole seizure model. It also significantly increased the onset of seizures at doses of 40 mg/kg and 80 mg/kg (p<0.005 and p<0.05 respectively). The extract did not exhibit significant activity in maximal electroshock seizure model. In the 4-amino pyridine-induced seizure test, at doses of 20 mg/kg, 40 mg/kg and 80 mg/kg, there was only 16.7%, 16.7% and 0% protection against seizure. The corresponding mortality rates were also high: being 83.3%, 83.3% and 100% respectively. However, onset of seizures was found to be significantly different from saline control at p<0.001, p<0.05 and p<0.05 for 20, 40, and 80 mg/kg respectively.. The extract resulted in significant decreases in the onset of sleep at doses of 20 mg/kg, 40 mg/kg and 80 mg/kg (p<0.05, p<0.005 and p<0.005 respectively); and significant increases in the duration of sleep (same graded doses of 20, 40 and 80 mg/kg) at p<0.005, p<0.05 and p<0.005 respectively. The number of head dips were significantly decreased at p<0.001 for all the tested doses of the extract. From the beam walking test for motor deficits, the result showed a significant increase in the

number of foot slips at doses of 20 mg/kg, 40 mg/kg and 80 mg/kg (p<0.001, 0.005 and p<0.005 respectively); with no significant difference in the time taken to cross the two ends of the beam (time taken to complete the task). The median lethal dose (LD50) values of F. vallis extract were found to be 471.2 mg/kg (i.p.) and >5,000 mg/kg (p.o.) in mice whereas that found in chicks were 774.6 mg/kg (i.p.) and >5,000 mg/kg (p.o.). The preliminary phytochemical screening reveals the presence of saponins, alkaloids, flavonoids, tannins and glycosides. These results suggest that, F. vallis extract possess biologically active compounds that have anticonvulsant properties, and are sedative in nature.