Seoritae extract reduces prostate weight and suppresses prostate cell proliferation in a rat model of benign prostate hyperplasia

Abstract

Seoritae is a type of black soybean that is known to have health-promoting effects due to its high isoflavone and anthocyanin contents. We evaluated whether Seoritae extract (SE) had beneficial effects on the reduction of prostate weight in a rat model of benign prostatic hyperplasia (BPH). BPH was induced by intramuscular injections of testosterone enanthate once a week for 5 weeks in Sprague-Dawley rats, and rats were treated with or without daily oral doses of SE during BPH induction. After 5 weeks, the oxidative stress (superoxide dismutase and 8-hydroxy-2-deoxyguanosine), apoptosis (caspase-3), and activity of 5-alpha reductase were evaluated in the serum and prostate. The SE treatment group showed a significant decrease in prostate weight, oxidative stress, apoptosis, and 5-alpha reductase activity compared to the nontreated BPH group. These results show that SE is effective in decreasing the weight and proliferation of the prostate, and suggest that SE may be an effective treatment for BPH.

Figure 1

HPLC chromatogram of the Seoritae extract. (a) Six peaks were obtained and each peak represented the isoflavone content. (b) The peak with the circle indicates Cyanidin-3-O-glucoside in standard compounds. A corresponding peak was seen in the SE HPLC chromatogram (black arrow).

Figure 2

Histological analysis of prostate specimens taken from each experimental group. (a) Secretory luminal cells were lined with a single layer of low columnar epithelium and the acini were filled with pale eosinophilic materials (H & E stain, ×200). (b) The epithelial cells in glands were arranged as several uneven layers and the gland was excessively developed (H & E stain, ×200). (c) In comparison to (b), the proliferation of columnar epithelial cells in the BPH + SE1 group was restricted, and the development of the gland was limited (H & E stain, ×200). (d) It is difficult to find a difference between (d) and (a), except for the multiple layers of columnar epithelial cells in some parts of the gland in (d). H & E: hematoxylin and eosin; (a) control; (b) BPH; (c) BPH + SE1; (d) BPH + SE2.