Experimental evaluation of antidepressant and antianxiety activities of aqueous leaf extracts of Senna alata (L.) Roxb. using in vitro animal models

Abstract

Objective: In the present investigation antidepressant and antianxiety activities of aqueous leaf extracts of Senna alata (200 mg/Kg) were carried out to establish the species as a potent natural antidepressant and anxiolytic drug. Methods: Antidepressant activity was carried out using forced swim test and tail suspension test. In both these tests, the animals were subjected to external stress that results in alteration of the behavior of animal due to fear. The antianxiety activity of aqueous leaf extracts of S. alata has been studied by the elevated plus-maze test in rats. The mean number of entries and the time spent in the open arm after 45 min of the administration of test drug was noted to determine the antianxiety effect of the test drug. Results: For antidepressant activity administration of test drug (200 mg/Kg) showed a significant decrease in the time spent by the animal in state of depression in both the assays which clearly indicates that the aqueous leaf extracts of S. alata exhibited a strong antidepressant activity similar to that of the control drug (Imipramine). In the antianxiety activity, administration of aqueous leaf extract (200 mg/Kg) of S. alata significantly increased the mean number of entries (2.25±0.98) in the open arm and the time spent in open arm (2.23±0.04) compared to the control group. The activity of the extract was slightly greater than standard drug Diazepam. Conclusion: From the above-presented results, it can be concluded that administration of Senna alata aqueous leaf extracts (200 mg/Kg) showed a considerable decrease in both antidepressant and antianxiety activities in all the test animals and can be used in the replacement of commercially available synthetic drugs in the near future.