keywords: Anticonvulsant, Epilepsy, Isoniazide, Pentylenetetrazole, Strychnos spinosa , 4-aminopyridine.
Strychnos spinosa is a pantropical plant with wide applications in the treatment of both communicable and non-communicable diseases. The objective of this study is to evaluate the anticonvulsant activities of methanol leaf extract of Strychnos spinosa at 150, 300 and 600mg/kg in experimental animals. Phytochemical screening and acute toxicity studies were conducted on the extract as well as evaluation of anticonvulsant activity against maximal electroshock induced convulsions in a day old chicks, pentylenetetrazole, 4-aminopyridine, strychnine, picritoxin and isoniazide induced seizures in mice. The median lethal dose of Strycnos spinosa was estimated to be 2000mg/kg in mice and >5000 mg/kg in chicks. Phytochemicals screening revealed the presence of alkaloids, flavonoids, cardiac glycosides, saponins, tannins, streroids, anthraquinones and triterpines. The extract provided 30% seizure protection at 300mg/kg against maximal electroshock test. Protection of 66.67% was offered at 300 and 600 mg/kg against pentylenetetrazole induced convulsions. There was significant(p<0.001) increase in the mean onset of 4-aminopyridine induced convulsions at 300 and 600 mg/kg. Protections was provided in 50% of the mice at 300mg/kg in strychnine induced convulsions model. Upto 16.67% seizure protection was observed at both 150 and 300 mg/kg against picritoxin induced convulsions. On isoniazide induced convulsions the plant extract (150 mg/kg), diazeparm(5 mg) and pyridoxin(300 mg/kg) each provided 83.33% seizure protection, similarly, there was significant increase in the mean onset of seizures by the extract (150 mg/kg)(p<0.01) and diazeparm(5 mg)(p<0.001). The result revealed that the methanol leaf extract of Strychnos spinosa possesses anticonvulsant activity against different models of epilepsy. This provides scientific credence for the ethno-medical use of the plant in the management of various types of epilepsy.