Evaluation of Antidepressant and Anxiolytic Activity of Solanum melongena L. Fruits Aqueous Extract via Monoaminergic and GABAergic Pathway

Abstract

The current study proposed the in vivo antidepressant and anxiolytic activities of the aqueous extract from Solanum melongena fruits (AESM) in mice. The mice were administered with AESM 100 and 200 mg/kg, p.o. for anxiolytic (elevated plus maze test (EPMT) and locomotor action), and antidepressant (forced swimming test (FST) and tail suspension test (TST) activities. The possible mechanism of action of Solanum melongena fruits was also analyzed by measuring the level of serotonin (5HT), monoamine oxidase enzyme (MAO-A) and GABA activity in the blood of experimental animals. When mice were treated for seven days with 100 (*** P < 0.01) and 200 mg / kg, AESM p.o. and 2 mg / kg, diazepam p.o. (*** P < 0.001) showed significant increases in the average time expended and the number of entries into the open arms of the EPMT, as compared to control group in dose dependent fashion. However, when mice were treated with standard Imipramine (10 mg/kg) (***P < 0.001), AESM 100 mg/kg (**P < 0.01) and 200 mg/kg (*P < 0.05) after day 7, there was significant reduction in locomotor activity in both TST and FST in dose dependent fashion. Monoamine oxidase - A level in the entire brain of mice were significantly reduced when pretreated with AESM 100 and 200 mg/kg, p.o. for 7 days as compared to control group in dose dependent fashion.  The mechanisms of action of antidepressant effect of Solanum melongena fruits extract act by increasing serotonin and also GABA. Moreover, the extract also decreased the MAO-A enzyme in the experimental animals. These results demonstrated that both of these doses. Of aqueous extract from Solanum melongena fruits possess potential antidepressant activities in dose dependent fashion.