The effects of four extracts on prostate enlargement, the protein expressions of DHT and 5α-reductase (5AR), the mRNA expressions of androgen receptors (AR), prostate-specific antigen (PSA), and proliferating cell nuclear antigens (PCNA) in prostate tissues were evaluated in a testosterone propionate (TP)-induced BPH rat model. Here, KLK3 is linked to benign prostatic hyperplasia.