Piperine reverses the effects of corticosterone on behavior and hippocampal BDNF expression in mice.

A mouse model of depression has been recently developed by exogenous corticosterone administration. The present study aimed to examine the antidepressant-like effect and the possible mechanisms of piperine, a major alkaloid of black pepper (Piper nigrum Linn.) and long pepper (Piper longum Linn.), in corticosterone-induced depression in mice. The results showed that 3-weeks corticosterone injections caused depression-like behavior in mice, as indicated by the significant decrease in sucrose consumption and increase in immobility time in the forced swim test and tail suspension test. Moreover, it was found that brain-derived neurotrophic factor protein and mRNA levels in the hippocampus were significantly decreased in corticosterone-treated mice. Treating the animals with piperine significantly suppressed behavioral and biochemical changes induced by corticosterone. The results suggest that piperine produces an antidepressant-like effect in corticosterone-treated mice, which is possibly mediated by increasing brain-derived neurotrophic factor expression in the hippocampus.