Neuropharmacological Screening and Lack of Anti- Depressant Activity of Standardized Extract of Fumaria Indica: a Preclinical Study

The standardized 50% ethanolic extract of Fumaria indica (FI) containing 0.45% fumaric acid and 0.35% dimethyl fumarate w/w, was used in this study. Five groups of rats and mice of either sex, each group comprising of six animals, were used (i.e. control, respective standard drug, and 100 mg/kg, 200 mg/kg and 400 mg/kg doses of FI, p.o.). Potentiation of pentobarbital induced sleeping time, locomotor activity, effect on muscle grip performance of mice, maximal electroshock seizures (MES) in rats and pentylenetetrazole (PTZ) induced convulsions in mice were used as behavioural models to evaluate general effects of the FI on central nervous system. Further, antidepressant activity of the extract was also evaluated using validated models of depression in rodents viz. behavioural despair test, learned helplessness test, tail suspension test, reserpine induced hypothermia, 5-Hydroxytryptophan (5-HTP) induced head twitches in mice and L-dopa induced hyperactivity and aggressive behaviour in mice. The animals treated with FI showed significant and dose dependent increase in pentobarbital-induced sleeping time and marked decrease in onset of sleeping time in rats. FI and diazepam have shown significant decrease in locomotor activity. FI did not show any muscle relaxant effect in the rota-rod test in mice while diazepam has shown significant muscle relaxant effect. FI, phenobarbitone and diazepam showed significant anticonvulsant activity in MES in rats and PTZ induced convulsions in mice respectively. However, no antidepressant activity was observed with FI in any of above six validated models of depression. It may be concluded that FI has significant central nervous system depressant activity and lacking antidepressant activity in rodents.