Evaluation of antidepressant-like activity of glycyrrhizin in mice Evaluation of antidepressant-like activity of glycyrrhizin in mice Evaluation of antidepressant-like activity of glycyrrhizin in mice Evaluation of antidepressant-like activity of glycyrrhizin in mice Evaluation of antidepressant-like activity of glycyrrhizin in mice

Objective: To investigate the antidepressant-like effect of glycyrrhizin (glycyrrhizic acid ammo­ nium) in mice. Materials and Methods: Glycyrrhizin (1.5, 3.0 and 6.0 mg/kg, i.p.) was administered once daily Pharmacology Division, for seven successive days to separate groups of young male Swiss albino mice. The immobility Dept. Pharmaceutical periods of control and treated mice were recorded in forced swim test (FST) and tail suspension Sciences, test (TST). Effect of sulpiride (50 mg/kg, i.p.; a selective D 2 receptor antagonist), prazosin (62.5 Guru Jambheshwar µg/kg, i.p.; an α 1 -adrenoceptor antagonist) and p-chlorophenylalanine (100 mg/kg, i.p.; an inUniversity, hibitor of serotonin synthesis) on antidepressant-like effect of glycyrrhizin in TST was also studHisar-125001 (Haryana), ied. The antidepressant-like effect of glycyrrhizin was compared to that of imipramine (15 mg/ India. kg, i.p.) and fluoxetine (20 mg/kg, i.p.) administered for seven successive days. Received: 6.5.2005 Results: Glycyrrhizin produced significant antidepressant-like effect at a dose of 3.0 mg/kg adRevised: 29.7.2005 ministered for seven successive days, as indicated by reduction in the immobility times of mice Accepted: 9.9.2005 in both FST and TST. Glycyrrhizin did not show significant effect on locomotor activity of mice. The efficacy of glycyrrhizin was found to be comparable to that of imipramine and fluoxetine. Correspondence to: Sulpiride and prazosin significantly attenuated the glycyrrhizin-induced antidepressant-like efDinesh Dhingra fect in TST. On the other hand, p-chlorophenylalanine did not reverse antidepressant-like effect E-mail: of glycyrrhizin. This suggests that the antidepressant-like effect of glycyrrhizin seems to be medi­ din_dhingra@rediffmail.com ated by an increase in brain norepinephrine and dopamine, but not by an increase in serotonin. Conclusion: The results of the present study indicate the involvement of adrenergic and dopaminergic systems in the antidepressant-like effect of glycyrrhizin.