Objective To observe the intervention effects of Baihe Xiaoyao Powder on depression model rats and its possible mechanism. Methods Sixty rats were randomized into the blank group

model group

western medicine group

Chinese medicine group and integrative medicine group

with 12 in each. The depression models were established by unpredictable mild stress in all groups except the blank group. Twenty-eight days later

the western medicine group was given 12. 8 g /（ kg·d） Fluoxetine solution

Chinese medicine group was given 12. 8 g /（ kg·d）Baihe Xiaoyao Powder solution

integrative medicine group was given both Fluoxetine solution and Baihe Xiaoyao Powder solution and the blank group and model group were given equal volume of normal saline for 28 days. The body weight gain and behavioral changes of rats in all groups were observed before and 1

2

4 weeks after treatment. The levels of triiodothyronine（ T3）

thyroxine（ T4）

thyroid stimulating hormone（ TSH）

adrenocorticotropic hormone（ ACTH）

cortisol（ CORT）

luteinizing hormone（ LH）

estradiol（ E2） and follicle-stimulating hormone（ FSH）were detected after treatment finished. Results Comparing with the model group

the body weight gain

upward time and total consumption of liquid and syrup were significantly increased but the immobility time was significantly decreased in all administration groups after 2-week and 4-week administration

especially in the integrative medicine group（ P < 0. 01）. Comparing with the model group

the levels of ACTH

CORT

T4

TSH

LH and FSH were significantly decreased but the levels of T3 and E2 were significantly increased in all administration groups（ P < 0. 01）

especially in the integrative medicine group（ P < 0. 05 or P < 0. 01）. Comparing with the western medicine group

the levels of ACTH

T4

LH and FSH were significantly decreased but the levels of T3 and E2 were significantly increased in the Chinese medicine group（ P < 0. 05）. Conclusion Baihe Xiaoyao Powder has an obvious antidepressant effect. Possibly

one of its important mechanisms is adjusting disorder hormone levels. The combination of Baihe Xiaoyao Powder and Fluoxetine Hydrochloride Tablets has synergistic effect.