Effect of gold nanoparticles treatment on the testosterone-induced benign prostatic hyperplasia in rats

Background: Gold nanoparticles (AuNps) are promising agents for prostate cancer therapy. Herein, the in vivo effects of 20 and 50 nm sized AuNps on experimentally induced benign prostatic hyperplasia (BPH) was examined. Materials and methods: Adult male rats were divided into four groups (n=6–8 each). A negative control group and three groups were injected daily with testosterone (3 mg/kg/subcutaneously) to induce BPH. Animals receiving testosterone were randomized to untreated BPH group and two BPH groups which were treated intraperitoneally with 20 and 50 nm AuNps (5 mg/kg/daily) in addition to testosterone. After three weeks, histopathological changes and serum levels of testosterone and dihydrotestosterone (DHT) were analyzed. In addition, the prostate tissue levels of transforming growth factor-β(1) (TGF-β(1)), vascular endothelial growth factor-a (VEGF-A) and interleukin-6 (IL-6) were measured using ELISA. Results: There were significant increases in the prostate weight/body weight ratio, serum testosterone and DHT and in the prostate tissue content of TGF-β(1), IL-6 and VEGF-A in the untreated BPH group. histological examination showed morphological abnormalities with more proliferation in the glandular epithelial and stromal area and with abundant epithelial papillary folds in the BPH group. Simultaneous administration of 50 nm AuNps with testosterone tended to increase the prostate weight/body weight ratio and increase the tissue level of IL-6 in compared to the BPH group. Conversely, treatment with 20 nm AuNps significantly reduced the elevated tissue content of TGF-β(1), IL-6, and VEGF-A. Histopathological examination also showed that 20 nm but not the 50 nm AuNps administration ameliorates testosterone-induced prostatic hyperplasia. Conclusions: In experimentally induced BPH, AuNps can inhibit the progression of BPH in a size-dependent manner. while 20 nm AuNps ameliorate BPH by its inhibitory effects on the prostatic cell proliferation, inflammation and angiogenesis, the 50 nm AuNps could potentially exacerbate the development of BPH in rats, mainly through enhancing the inflammatory process.