Objective:To extract Rabdosia japonica var. glaucocalyx diterpenes by heating reflux to determine the contents of diterpenes and study the effect of R. japonica var. glaucocalyx diterpenes on the liver Qi stagnation and kidney deficiency model of precancerous breast lesions. Method:Female SD rats were randomly divided into 4 groups

namely normal group

tamoxifen citrate group

model group

and R. japonica var. glaucocalyx diterpenes group. All of the groups except for normal group were given DMBA combined with multi-composite stress. Changes in biological characterizations of rats were observed and recorded after successful modeling. Diterpenes were given to R. japonica var. glaucocalyx diterpenes group

while distilled water was given to normal group and model group. Intragastric administration was performed for consecutively 30 days. Thirty days later

blood was collected from abdominal cavity and breast tissues for pathological examination. Incidence of tumors was recorded. Serum estradiol (E2) and progesterone (P) levels were detected by enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was adopted for observing the pathological changes. Expressions of vascular endothelial growth factor (VEGF)

chemokine receptor (CXCR4) protein and mRNA were detected by Real-time PCR and Western blot. Result:The dried products weighed 2.162 g

including 26.35% of diterpenes. Compared with normal group

a series of biological changes were observed in model group. The levels of E2 and P in R. japonica var. glaucocalyx diterpenes group were lower than those of model group (P<0.05). VEGF and CXCR4 protein and mRNA expressions were lower than those in model group(P<0.05). Conclusion:R. japonica var. glaucocalyx diterpenes can prohibit VEGF and CXCR4 mRNA and protein expressions

angiogenesis and chemokine receptor expressions

and regulate hormone levels in rats

so as to inhibit the carcinogenesis of precancerous breast lesions in rats.