Antidepressant-like effects of Brassica juncea L. leaves in diabetic rodents.

The objective of the study was to evaluate for antidepressant like activity of a methanolic extract of B. juncea leaves (BJ 100, 200, and 400 mg/kg/day, po), and Imipramine (15 mg/kg/day, po) in alloxan monohydrate (120 mg/kg, ip) induced diabetic and nondiabetic rodents, using behavioural despair, learned helplessness, and tail suspension tests for antidepressants and locomotor activity test for quantifying the behavioural effects of treatments. In addition, effects of BJ treatments on brain levels of norepinephrine, serotonin and dopamine were also estimated. Enhanced depressive states, and motility were observed in diabetic animals. Antidepressant and motor function depressing effects of BJ were apparent in all behavioural tests in diabetic rats and mice only. Decreased contents of dopamine, norepinephrine and serotonin in brain of diabetic rats were also dose dependently compensated by repeated daily BJ treatments. However, brain dopamine level of BJ treated normal rats was higher than that in control nondiabetic. The results suggest that BJ could be a nutritional alternative for combating exaggerated depression commonly associated with diabetes.