Psychopharmacological and Anticonvulsant Effects of Litsea polyantha Juss Bark Extract in Mice

Abstract

The aim of the present study is to investigate psychopharmacological and anticonvulsant activities of methanolic extract of Litsea polyantha Juss. in animal models and to determine its possible anticonvulsant mechanism. Anticonvulsant activity of methanolic extract of Litsea polyantha Juss. (50, 75 and 100 mg/kg, i.p.) was studied in seizures induced by maximum electroshock and pentylenetetrazol. Cyproheptadine, a nonselective (5HT_1/2) serotonin antagonist (4 mg/kg, i.p.) was used to study the reversal of protective effect of extract in the above mentioned models. Extract showed no neurotoxicity, potentiated pentobarbitone induced sleep and inhibited seizures induced by maximum electroshock in a dose dependent manner. Anticonvulsant effect of extract was comparable to clinically used antiepileptic drugs (phenytoin and diazepam). However, pentylenetetrazol induced seizures were not inhibited. Animals pretreated with cyproheptadine showed inhibition of the anticonvulsant effect of extract. Inhibition of the anticonvulsant effect of extract by cyproheptadine substantiates the involvement of serotonergic pathways for the anticonvulsant activity of extract.