Determination of Optimal Dosage of Ethanol Extract of Houttuynia cordata Thunberg Against Benign Prostatic Hyperplasia

Houttuynia cordata Thunberg has been studied for a variety of pharmacological actions in traditional oriental medicine. In this study, we investigated the effects of Houttuynia cordata ethanol extract (HCE) on benign prostatic hyperplasia (BPH) models induced by castration and testosterone propionate (TP) injection. Thirty rats were divided into six groups. One group was used as a normal control, and the other groups were castrated and had intraperitoneal injections of TP for 14 days to induce BPH. A positive control group was given daily doses of finasteride (5 mg/kg) to the BPH model. Rats administered HCE (0.5, 1 or 2 mg/kg) instead of finasteride were compared with controls as experimental groups. There was no statistical significance in terms of prostate weight based on 100 g of body weight. The concentrations of 5-α reductase and dehydroxytestosteronre (DHT) were determined via ELISA tests, and there was a significant decrease in all experimental groups. The 0.5 mg/kg HCE group had the lowest level of 5-α reductase, and the 2 mg/kg HCE group had the lowest level of DHT. In the histopathological observation of prostates, the control and the 2 mg/kg HCE groups had normal cell shapes and no swelling. However, in the negative control group and the 1 mg/kg HCE group, the cells were swollen, and the gap between the cells was narrowed. In particular, in the 0.5 mg/kg HCE group, some cells were bursting. Therefore, the administration of more than 2 mg/kg of HCE is suitable to protect against BPH.