Objective: To study the therapeutic effect and mechanism of Longdan Xiegan Tang on polycystic ovary syndrome (PCOS) model and provide a preliminary experimental basis for the application of PCOS. Method: Totally 50 SD rats were randomly divided into normal group (n=10) and modeling group (n=40). PCOS models were established by using insulin (INS) and human chorionic gonadotropin (HCG). The successfully modeled rats were then divided into model group

Daying-35 group (0.21 g · kg-1)

Longdan Xiegan Tang high-dose group (29.6 g · kg-1) and low-dose group (7.4 g · kg-1). After continuous intragastric administration of 15 d

we analyzed the ovarian weight and volume. The levels of luteinizing hormone (LH)/follicle stimulating hormone (FSH)

testosterone (T)

fasting blood glucose

fasting insulin (INS) and levels of inflammatory cytokines interleukin (IL)-2

IL-4

IL-6 and IL-10; Western blot was used to analyze protein expression of JAK2

STAT3

p-STAT3 and IL-6 in ovarian tissues. Result: As compared with the normal group

ovarian weight and volume were significantly increased; LH/FSH

T

fasting blood glucose and INS levels in serum were significantly increased; IL-2

IL-6 and IL-10 levels were significantly increased; and JAK2

STAT3 and IL-6 protein expression levels were also up-regulated in model group (P<0.05). As compared with the model group

high dose and low dose Longdan Xiegan Tang significantly decreased ovarian weight and volume

LH/FSH

T

fasting blood glucose and INS levels in serum as well as IL-2

IL-6 and IL-10 levels

increased JAK2

STAT3 protein expression and reduced p-STAT3 and IL-6 protein expression (P<0.05). Conclusion: Longdan Xiegan Tang has obvious curative effect on PCOS rats by decreasing hormone level and inhibiting inflammatory reaction and the mechanism may be related to JAK2/STAT3 pathway.