Objective: To study the effects of Xiaoyao San (XYS) and its effective compositions on behavior and memory in chronic unpredictable mild stress (CUMS) model rats

so as to reveal the characteristics of different effective compositions that represent different therapeutic methods. Method: Wistar rats were randomly divided into eight groups:XYS group (30 g·kg-1)

Shugan (SG) group (5.25 g·kg-1)

Yangxue (YX) group (9 g·kg-1)

Shugan+Jianpi (SG+JP) group (21 g·kg-1)

Yangxue+Jianpi (YX+JP) group (24.75 g·kg-1)

control group

model group

and amitriptyline group (10 mg·kg-1). The rat depression model was established by using chronic unpredictable mild stressors and solitary feeding condition as described in the literature. All rats were intragastrically administrated with different decoctions or distilled water for 4 weeks. Weights

preference for 1% sucrose solution (PSS)

autonomic activities and Morris water maze test (MWMT) were carried out in different time. Result: Compared with model group

growth of weight

PSS

autonomic activities

as well as moving distance percentage at target quadrant and entering frequency into valid area in MWMT were significantly increased by XYS

SG

YX

SG+JP and YX+JP group. Meanwhile

the escape latency in Morris test was decreased also by those five groups above. XYS

SG and SG+JP groups were compared with YX and YX+JP groups respectively. The amelioration effects of former groups on CUMS model rats were better than that of later groups. Especially

the effects of SG group were more prominent than other groups when treated for 2 weeks. Conclusion: The decoction of XYS can improve behavior and memory in rat CUMS model

showing antidepressant effect. The SG compositions play a principal role in antidepressant effect of Xiaoyao San formula

while the YX drug-group serves as an important assistant to the antidepressant effect of Xiaoyao San.