Determination of optimal dosage of extract of Angelica gigas Nakai against benign prostatic hyperplasia

Purpose: To investigate the effect of Angelica gigas Nakai ethanol extract (AGNEX) on benign prostatic hyperplasia (BPH) models induced by castration and testosterone propionate (TP) injection. Methods: 30 rats were randomly divided into six groups of five rats each. One group was used as a normal control (CON) and the other groups were castrated and injected intraperitoneally with TP to induce BPH. Positive control group (PCON) was administered finasteride (5 mg/kg) for 4 weeks and BPH-induced group without treatment was used as negative control (NCON). Groups administered AGNEX (1.25 mg/kg (AG1.25), 5 mg/kg (AG5), or 10 mg/kg (AG10)) instead of finasteride were assigned as study groups. The complete blood cell and lipid profiles, liver and kidney function assays, serum 5α-reductase activity and DHT levels as well as the histological examination of prostate tissues were determined. Results: The prostate volume of AG10 group decreased by approximately 35 % compared to BPH induced group (NCON). The prostate weight ratio decreased by 10 % in BPH + finasteride group compared to NCON group, and by 24 and 22 % in the AG5 and AG10 groups, respectively. AG10 group exhibited the lowest levels of 5α-reductase and dihydrotestosterone. Histopathological observations of prostate tissue showed normal cell shapes and reduced intraluminal polyp formation in the control and AGNEX-administered groups. Conclusion: The administration of 10 mg/kg of AGNEX is optimal dose for protective effect against BPH. Therefore, AGNEX has potentials for further investigations as source of lead agents for BPH management.