Effect of Puyu Capsules on behavior,HPA axis and CREB-BDNF pathway expression in hippocampus of depressed mice

Abstract

This study aimed to investigate the antidepressant effects of Puyu Capsules and its potential mechanism. The antidepressant activity of Puyu Capsules was evaluated by forced swimming test(FST) and tail suspension test(TST) after subchronic administration in mice. Next, the mice were subjected to a chronic unpredictable stress(CUS) protocol for a period of 28 d to induce depressive-like behaviors. Then, a sucrose preference test, open-field test and novelty-suppressed feeding test were performed to evaluate the antidepressant effect of Puyu Capsules. After the behavioral test, the adrenal index was calculated; the levels of serum corticosterone(CORT) and adrenocorticotropic hormone(ACTH) were detected by enzyme-linked immunosorbent assay(ELISA); the levels of glucocorticoid receptor(GR), protein expression of brain-derived neurotrophic factor(BDNF), and the ratio of phosphorylated cAMP response element binding protein(CREB) to total CREB were detected by Western blot to explore the antidepressant function and mechanism of Puyu Capsules. The results suggested that Puyu Capsules had significant antidepressant effects on both the depression model and CUS model. At the same time, the drug could prevent the change of adrenal index induced by CUS and reverse the abnormal activation of CORT and ACTH in the serum of depressed mice. Finally, Puyu Capsules could also reverse the lower expression of pCREB, BDNF and GR in the hippocampus of CUS mice. In conclusion, Puyu Capsules produced significant antidepressant effects, and the mechanism was closely related to hypothalamic pituitary adrenal(HPA) axis activity, GR and CREB-BDNF pathway expression.