Objective:To investigate the effect of Kangquan Recipe(康泉方,KQR) on bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) expression and its mechanism in rats with benign prostatic hyperplasia (BPH).Methods:Forty-eight male Sprague-Dawley rats were divided into 6 groups using a random number table,with 8 in each group:the normal group (normal saline 10 ml/kg),the model group (normal saline 10 mL/kg),the finasteride group (0.5 mg/kg),the low-dose KQR group (3.5 g/kg),the middle-dose KQR group(7 g/kg),and the high-dose KQR group (14 g/kg).The 40 rats were subcutaneously injected with testosterone propionate after castration for 30 days to establish the BPH rat model except for those in the normal group.At the same time,the corresponding drugs were administered by gavage for 30 consecutive days.The effects of different doses of KQR on the protate wet weight,prostate volume and prostate index (PI) were observed.The changes in histopathology were monitored with hematoxylin-eosin staining.BAMBI protein and mRNA expression contents were determined by Western blot and quantitative real-time polymerase chain reaction,respectively.Results:All doses of KQR could decrease prostatic epithelial tissue proliferation.Compared to the model group,the high and middle-dose KQR significantly reduced prostate wet weight,prostate volume and PI;increased BAMBI protein expression in the hypothalamus,pituitary and prostate tissue;all doses of KQR up-regulated BAMBI mRNA expression in serum,prostatic fluid and prostate tissue (P＜0.05 or P＜0.01).Conclusions:KQR could inhibit the proliferation of rat prostatic tissue,promote BAMBI protein expression in the hypothalamic-pituitary-prostate of rats with BPH;and increase BAMBI mRNA expression in the blood,prostatic fluid and prostate tissue of rats with BPH,showing a dose-effect relationship.KQR can be used as a potential drug for the treatment of BPH.