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

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. (C) 2011 Elsevier Ireland Ltd. All rights reserved.