Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are two of the more harmful prostatic diseases in the elderly men. The incidence of BPH and PCa goes up with the ageing population. Literature search shows that steroid 5a-reductase is a membrane-bound NADPH-dependent enzyme that catalyzes the reduction of testosterone (T) to the more potent androgen dihydrotestosterone(DHT), which promotes the development of BPH. The majority of PCa responds to antiandrogen therapy by temporary remission in its i...