The Therapeutic Effects of Native Halophyte, Suaeda glauca Bunge and Its Constituents on Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is one the most common urinary disorders in elderly men, occurring when the prostate, which surrounding the urethra, undergoes abnormal enlarges and obstructs urine flow. Within the prostate, testosterone is converted to dihydrotestosterone (DHT) by the lipophilic enzyme 5α-reductase. Excessive accumulation of DHT binds to androgen receptors (AR), causing the hyperproliferation of stromal and epithelial cells, which increases the size of the prostate. In the process of exploring new materials with efficacy for improving BPH from halophytes native to Korea, Suaeda glauca (Bunge) Bunge was found as a promising candidate. S. glauca is an annual plant belonging to the Amaranthaceae family. In human prostate cell lines RWPE-1 and LNCaP, the ethanolic extract of S. glauca (ESG) effectively reduced the expression levels of AR, 5α-reductase type 2 (5αR2), proliferating cell nuclear antigen (PCNA) and prostate-specific antigen (PSA) proteins, compared to finasteride, a positive control. HPLC-DAD analysis of ESG using eight compounds isolated from S. glauca identified kaempferol-3-O-β-D-glucoside as one of the major components in ESG. Among the compounds 1–8, the effects of hydroxytyrosol (8) on BPH-related proteins were most remarkable in both cell lines. These results suggest that S. glauca and its bioactive compounds may be promising novel candidates for the prevention or treatment of BPH