Objective: To observe the effect of Danggui Buxue Tang on behavior and hypothalamic-pituitary-adrenal (HPA) axis in rat models of chronic stress-induced depression. Method: Totally 120 male SD rats were randomly divided into normal group

model group

Danggui Buxue Tang high

medium and low dose groups (8

4

2 g·kg-1)

and fluoxetine positive control group (3.33 mg·kg-1). Chronic unpredictable mild stress (CUMS) was used to establish the rat depression model. They were orally administered with corresponding drugs for 21 days and the rats in normal group and model group received the equal volume of normal saline. All rats' behavior changes were observed through open field test (OFT)

forced swimming test (FST) and tail suspension test (TST) at 0

7

14

21 d; serum cortisol (CORT) and adrenocorticotropic hormone (ACTH) levels of rats were also detected by ELISA at 21 d. Meanwhile

Real-time PCR method was used to detect the mRNA expression levels of corticotrophin-releasing hormone (CRH) and glucocorticoid receptor (GR) in hypothalamus

pituitary and hippocampus of rats. Result: Danggui Buxue Tang high and middle dose groups can significantly reduce the immobility time in forced swimming test and hanging tail test of depression model rats (P<0.05); significantly increase the number of grid crossing in open field test (P<0.05)

and significantly reduce the serum ACTH and CORT levels (P<0.05); Danggui Buxue Tang high dose group can down-regulate CRH mRNA expression level

and up-regulate the GR mRNA expression levels in the hypothalamus

pituitary and hippocampus (P<0.05). Conclusion: Danggui Buxue Tang can improve the depressive behavior in CUMS rats and show the anti-depression effect. Its mechanisms may be related to regulating HPA axis function.