The expressions of TGF-β1 and VEGF immunohistochemistry of prostate tissue from the rats (×100). Control, not treated group; BPH, testosterone induced BPH group; KH053, testosterone induced BPH with KH053 (200 mg/kg) group; finasteride, testosterone induced BPH with finasteride (1 mg/kg. p.o.) group. To determinate a mechanism which could explain the effects of KH053 on BPH, the expression of TGF-β1 and VEGF in the rat prostates were examined. As shown in Fig. 2, immunohistochemical results showed TGF-β1 and VEGF are rarely expressed in normal prostate, weak labeling observed in prostatic tissues in control group. Immunohistochemical detection also revealed an increase in TGF-β1 and VEGF expression in prostatic epithelial cells in the BPH model group. A moderate expression of TGF-β1 and VEGF was also observed in the BPH model group. Immunohistochemical result shows that the level of VEGF was significantly higher in the BPH group, while no significant difference was seen in the KH053 group as compared with the finasteride group.