Anticonvulsant activity of ethanol leaf extract of Spathodea campanulata P. Beauv (Bignoniaceae)

The anticonvulsant properties of ethanol leaf extract of Spathodea campanulata, a plant used in traditional medicine to treat convulsion and epilepsy, were studied in mice using pentylenetetrazole-, picrotoxin-, and electroshock-induced models in mice. Other central nervous system effects and anticonvulsant-related activities such as the effects on position sense, righting reflex, Rota-Rod performance, phenobarbital sleep time, and amphetamine-induced stereotypy were also investigated. The acute toxicity potential in mice was determined by the oral route. The results showed that the administration of S. campanulata extract (250-1,000 mg/kg, p.o.) 30 minutes prior to intraperitoneal administration of pentylenetetrazole (70 mg/kg) or picrotoxin (5 mg/kg) protected the treated mice against the respective pentylenetetrazole- and picrotoxin-induced convulsion in a dose-dependent manner, offering 100% protection at the maximum dose of 1,000 mg/kg. The extract increased the threshold of maximum electroshock and reduced duration of convulsive episodes, dose-dependently. Oral administration of S. campanulata ethanol extract did not significantly (P > .05) affect other centrally coordinated behaviors and convulsion-related properties such as position sense, righting reflex, Rota-Rod performance, phenobarbital sleep time, and amphetamine-induced stereotypy in treated animals. The oral median lethal dose of the extract was estimated as 4.5 g/kg. These results show that the ethanol leaf extracts of S. campanulata possess anticonvulsant activity. The results also show that S. campanulata extract is nonsedating, has no antipsychotic properties, and may not affect motor coordination when used as an anticonvulsant.