Abstract
Depression is gradually becoming a primary mental disease threatening human health. Therefore, there is an urgent need to clarify the pathogenesis of depression and identify new effective natural antidepressants. This study aimed to investigate the antidepressant effects of baicalin and explore its potential mechanism in a mouse model of depression induced by chronic unpredictable mild stress (CUMS). Following a 6-week exposure to CUMS, mice were treated with baicalin (10 mg/kg) or fluoxetine (10 mg/kg) for 4 weeks by oral gavage. A sucrose preference test and a forced swimming test were performed to evaluate depression-like behaviors, and the levels of adenosine triphosphate (ATP) in the prefrontal cortex were measured. Moreover, gene expression and enzyme activities related to ATP production, and mitochondrial function, were monitored. The results indicated that baicalin and fluoxetine could alleviate CUMS-induced depression-like behaviors of mice. In addition, baicalin significantly elevated the ATP content and the expression of genes hexokinase 1 (Hk1), pyruvate dehydrogenase E1 alpha 1 (Pdha-1), isocitrate dehydrogenase (Idh), peroxisome proliferator-activated receptor, gamma, coactivator 1 alpha (Pgc-1α), and sirtuin-1 (Sirt1) in the prefrontal cortex. Furthermore, baicalin increased the activity of the respiratory chain complexes I and V as well as the mitochondrial membrane potential. In conclusion, baicalin may exert its antidepressant effect partly by upregulating the expression of some genes coding for enzymes involved in the glycolysis and the tricarboxylic acid cycle, and improving the mitochondrial function to enhance the ATP level in the brain.