Ameliorative Effect of Salvadora persica (Miswak) on Cigarette Smoke Induced Anxiety and Depression in Rats

Objectives: The aim of the study is to evaluate the anxiolytic and antidepressant activity of Salvadora persica in cigarette smoke-induced neurobehavior changes in rats. Methods: The lyophilized decoction of Salvadora persica (S. persica) was administered daily for four weeks by oral route at the doses 50, 100 and 200 mg/kg to the cigarette smoke exposed rats. The depression and anxiety studies were done by forced swim test and elevated plus maze test, respectively. The serum levels of monoamine oxidase-A and relative brain weight were also determined. The results were analyzed statistically by one-way ANOVA followed by Duncans’ multiple range tests. p<0.05 was considered to indicate the significance of results. Results: The observation from the study indicated that exposure of cigarette smoke for eight weeks significantly (p<0.01) enhanced the experimental parameters of depression and anxiety, besides increasing the monoamine oxidase-A and relative brain weight when compared with control animals. Administration of S. persica exhibited a dose-dependent inhibition in the neurobehavioral parameters. S. persica at 200 mg/kg produced significant (p<0.01) antidepressant and antianxiety effects. The treatment was also found to reduce the serum monoamine oxidase-A and relative brain weight in the cigarette smoked animals. Conclusion: The data suggests that decoction of S. persica might possess antidepressant and anxiolytic properties in the cigarette smoke exposed animals. These actions could be related to its antioxidant and reversal in the neurocircuilatory changes induced by the cigarette smoke.