Effects of Unripe Black Raspberry Extracts on Prostate Cancer Cell Line and Rat Model of Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH), which is commonly found in aging men, is characterized by hyper- plasia of prostatic stromal and epithelial cells beginning in the periurethral zone of the prostate. The prevalence of BPH increases in an age-dependent manner. Here, we investigated the protective effects of unripe Rubus occidentalis extracts (UROE) on BPH development using a prostate cancer cell line and testosterone-induced BPH rat model. Experiments using an established hormone-dependent prostate cancer cell line (LNCaP) showed that UROE treatment significantly decreased expression of androgen-related genes, including androgen receptor (AR), prostate specific antigen (PSA), and 5-alpha reductase 2, but not 5-alpha reductase 1, which was also observed in flutamide-treated cells. Further, AR and PSA gene expression was reduced by UROE treatment under androgen-stimulated conditions using dihy- drotestosterone (DHT). BPH animals displayed elevated prostate weights. However, UROE as well as finasteride treat- ment significantly reduced prostate weights and DHT levels compared to testosterone-induced BPH animals. Histopathological analysis also showed that UROE treatment suppressed testosterone-induced prostatic hyperplasia. Taken together, the results suggest that UROE may effectively inhibit the development of BPH and thus may be a useful agent in BPH treatment.