Background: Prolonged use of benzodiazepines to treat chronic anxiety disorders has adverse effects such as impaired cognitive function and motor control, tolerance, dependence and abuse. Ondansetron (5-HT3 receptor antagonist) and Ursolic acid (ubiquitous phytochemical) have anxiolytic activity comparable to Diazepam with no such adverse effects. This study evaluated and compared the effect of Ondansetron and Ursolic acid on chronic anxiety in rats using elevated plus maze (EPM) test, which is a validated animal model to investigate anxiolytic agents.
Methodology: Wistar albino rats of either sex (150-250 g) were divided into four groups with eight rats in each group. To induce chronic anxiety, all rats underwent forced swim test daily for 21 days after which the study groups were given distilled water (2 ml p.o.), Diazepam (1 mg/kg i.p.), Ondansetron (1 mg/kg i.p.) and Ursolic acid (0.2 mg/kg p.o.) respectively. Effect of test drugs on anxiety was evaluated using EPM test and parameters such as number of entries in open arms and closed arms as well as time spent in open arms were assessed. Results (mean±standard deviation) were analysed using one-way ANOVA test followed by Bonferroni’s correction.
Results: Statistically significant increase (p <0.05) was seen in time spent and number of entries in open arms in other three groups compared to Control group, in Diazepam group compared to Ondansetron and Ursolic acid groups, and in Ondansetron group compared to Ursolic acid group.
Conclusion: This study revealed that Ondansetron had significant anxiolytic activity compared to Ursolic acid in chronic anxiety.