The angiotensin converting enzyme inhibitor captopril attenuates testosterone-induced benign prostatic hyperplasia in rats; a mechanistic approach

Benign prostatic hyperplasia (BPH) is the most widespread urological disorder among elderly men. It is influenced by several factors, among which is the prostatic renin angiotensin system (RAS). Prostatic RAS activates several signaling pathways as proliferation, inflammation and angiogenesis that contribute to BPH development and progression. Captopril is a potent inhibitor of the angiotensin converting enzyme. Therefore, this study was performed to explore the potential protective effect of captopril against testosterone-induced BPH in rats. Male Sprague-Dawley rats were treated with either testosterone (3 mg/kg, s. c.) and/or captopril (100 mg/kg, orally) for four weeks. After treatments, prostatic serum markers and histopathology were assessed. Mechanistically, apoptotic, inflammatory and angiogenic pathways were examined. Testosterone significantly increased prostate weight, prostatic index, prostatic acid phosphatase and prostate specific antigen. These effects were almost prevented by captopril (100 mg/kg). Moreover, testosterone significantly elevated proliferating cell nuclear antigen and reduced Bax/Bcl-2 ratio, p53 and caspase-3 activity. Furthermore, it significantly elevated nuclear factor kappa-B, cyclooxygenase-II, tumor necrosis factor-α and interleukin-8. Besides, it caused a significant rise in vascular endothelial growth factor, basic fibroblast growth factor and matrix metalloproteinase-9. On the contrary, captopril effectively neutralised the proliferative, inflammatory and angiogenic effects of testosterone. Finally, the angiotensin-1 receptor expression in the BPH group was markedly decreased while captopril restored the receptor expression. Collectively, these findings indicate that captopril possesses a potent protective effect against testosterone-induced BPH via inducing apoptotic and suppressing inflammatory and angiogenic signaling pathways.