Attenuation of benign prostatic hyperplasia by hydrophilic active compounds from pigmented rice in a testosterone implanted rat model.

Benign prostatic hyperplasia (BPH) is a common chronic disease in aging men. The present study aimed to identify the active fraction of a purple rice extract and determine its anti-prostatic hyperplasia effect in a testosterone implanted rat model. The hexane insoluble fraction (HIF) which mainly contains hydrophilic phytochemicals from the purple rice crude ethanolic extract was defined as the active fraction, due to a potent effect on the downregulation of androgen receptor (AR) expression in malignant prostate cells, in addition to low toxicity for normal fibroblast cells.

Purple rice extract inhibits testosterone-induced rat prostatic hyperplasia and growth of human prostate cancer cell line by reduction of androgen receptor activation.

The preventive effects of purple rice crude ethanolic extract (PRE) were firstly investigated on testosterone-induced benign prostatic hyperplasia (BPH) in castrated rats. As compared to vehicle-treated rats, lower prostate weights were found in the BPH rats that received PRE 1 g/kg bw. In addition, the PRE treatment down-regulated the androgen receptor (AR) expression in the dorsolateral prostate of those rats.