Inhibition of MAO and GABA: Probable mechanisms for antidepressant-like activity of <i style="">Nardostachys jatamansi</i> DC. in mice

Abstract

Ethanolic extract (100, 200 and 400 mg/kg, po) of <i style="">N. jatamansi </i>administered for 14 successive days to Swiss young albino mice (either sex) produced significant antidepressant-like effect in both tail suspension and forced swim tests. The efficacy of the extract was found to be comparable to imipramine (15 mg/kg, po) and sertraline (20 mg/kg, po). Ethanolic extract (200 mg/kg, po) did not show any significant change on locomotor activity of mice as compared to control; hence it did not produce any motor effects. Further, the extract decreased the whole brain MAO-A and MAO-B activities as compared to control, thus increased the levels of monoamines. The antidepressant effect of the extract was also significantly reversed by pretreatment of animals with baclofen (GABA_B agonist); when tested in tail suspension test. The results suggested that the antidepressant-like effect of the extract may also be due to interaction with GABA_B receptors, resulting in decrease in the levels of GABA in mouse brain. Thus, the extract may have potential therapeutic value for the management of mental depression.