Antidepressant activity of Ondansetron in Albino Mice - A Case Study

The 5-HT3 receptors are ligand gated ion channels which mediate the release of number of neurotransmitters. Anxiolytic activity of ondansetron, a 5-HT3 antagonist has been shown in animals. Greenshaw suggested the possible involvement of 5-HT3 receptors in depression. Redrobe and Bourir reported the partial role of 5-HT3 and its receptors in the activity of antidepressants in forced swimming test in mice.

The study was done to evaluate the antidepressant potential of ondansetron and compare it with desipramine. The study included male swiss albino mice which were divided into five treatment groups and injected with Normal Saline 5ml/kg (control), desipramine 30mg/kg (standard), ondansetron 0.5 mg/kg, 1 mg/kg and 2 mg/kg (test drugs) intraperitoneally. Each group contained 6 animals. Duration of immobility was observed for 6 minutes in tail suspension test and for 4 minutes in forced swimming test on same set of animals after giving a sufficient wash out period of 4 weeks.

Results were analyzed by ANOVA followed by post hoc Tukey's test. Ondansetron at the above doses significantly reduced the immobility time in both the tests compared to control (p < 0.001). The reduction in duration of immobility was comparable to desipramine. The study showed that ondansetron has significant antidepressant activity in acute models of depression.