Finasteride (MK-906) acetate is a potent and competitive 5α-reductase inhibitor with an IC50 of 4.2 nM for type II 5α-reductase, demonstrating approximately 100-fold higher affinity for type II than type I. Finasteride acetate can be used for research on benign prostatic hyperplasia (BPH) and androgenic alopecia [1] [2] [3].

Finasteride, at a concentration of 10 μM over incubation periods of 6 to 24 hours, induces the expression of HO-1 and Nrf2 proteins in PC-3 cells, and also inhibits the conversion of [3 H]testosterone (T) to [3 H]dihydrotestosterone (DHT) in P. crustosum. In cell viability assays involving PC-3, DU-145, and LNCaP cell lines treated with finasteride at 10 μM for durations of 6, 12, and 24 hours, there was a noticeable increase in HO-1 protein expression in a time-dependent manner specifically in PC-3 cells. Additionally, finasteride triggered the expression of Nrf2 protein in DU-145 and PC-3 cells, though not in LNCaP cells.

Finasteride, administered orally at a dosage of 0.1-0.5 mg/kg once daily for 16 weeks, effectively reduces prostatic size in male dogs aged 2.7-11 years and weighing 10.3-49 kg with spontaneous benign prostatic hyperplasia (BPH), as indicated by a decrease in prostatic diameter (20%), volume (43%), and serum dihydrotestosterone (DHT) concentration (58%). This treatment does not negatively impact semen quality or serum testosterone levels and is free from adverse effects on the animals [3].