Antidepressant-like activity of beta-carotene in unstressed and chronic unpredictable mild stressed mice

The antidepressant-like activity of beta-carotene in Swiss young male albino mice subjected to chronic unpredictable mild stress was evaluated. Beta-carotene (50 and 100 mg/kg, p.o.) and imipramine (15 mg/kg, p.o.) per se were administered for 21 successive days to separate groups of unstressed and stressed mice. Higher dose (100 mg/kg) of beta-carotene and imipramine significantly decreased immobility period of mice in tail suspension test. These compounds significantly restored the reduced sucrose preference in stressed mice. There was no significant effect on locomotor activity of mice by the drugs. Beta-carotene significantly reversed stress-induced increase in brain catalase, monoamine oxidase (MAO-A), thiobarbituric acid-reactive substances (TBARS); and plasma nitrite and corticosterone levels; and increased stress-induced decrease in reduced glutathione levels. Thus, beta-carotene showed significant antidepressant-like activity in unstressed and stressed mice probably through inhibition of MAO-A and oxidative stress. Its antidepressant-like activity in stressed mice might also be due to decrease in plasma corticosterone levels.