Anticonvulsant activity of the methanolic extract of Justicia extensa T. Anders.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: To investigate the anticonvulsant activity of the leaf extract of Justicia extensa T. Anders used traditionally in the treatment of convulsion. MATERIALS AND METHODS: The anticonvulsant activity of the methanolic extract of Justicia extensa (50, 100 and 200 mg/kg, p.o.) was assessed in strychnine-induced (STR) and picrotoxin-induced (PCT) convulsion models in mice. Diazepam (1 mg/kg) and phenobarbitone (2 mg/kg) were used as reference drugs respectively. RESULTS: The extract showed no toxicity and significantly prolonged (p<0.01-0.05) the onset and reduced the duration of the seizures induced by picrotoxin (5 mg/kg, i.p.) in a dose dependent manner. Phenobarbitone completely inhibited the seizures in this model. Similarly, in the seizures induced by strychnine (1 mg/kg, i.p.), the extract also prolonged the onset and reduced the duration of the seizures though not in a dose dependent manner. Diazepam failed to inhibit the strychnine-induced seizures. The plant extract however showed a significantly higher anticonvulsant activity at 100 and 200 mg/kg in comparison with diazepam. CONCLUSIONS: The results obtained from this work suggest that Justicia extensa has anticonvulsant activity and this supports the use of the plant traditionally in the treatment of convulsion.