Ameliorative Effect of Olmesartan Medoxomil on Acetic Acid-Induced Colitis in Rats

Abstract

Background and aim: The renin–angiotensin system (RAS) is a homeostatic pathway widely known to regulate cardiovascular and renal physiology; however, little is known about its influence in gastrointestinal tissues. There are several reports showing influences by RAS and its key mediator angiotensin II (Ang II) on intestinal epithelial fluid and electrolyte transport. Data are accumulating, suggesting involvement in GI mucosal inflammation and carcinogenesis. Our target was to evaluate the protective alleviating effects of RAS blockade by using Olmesartan Medoxomil (OLM-M) with marked anti-inflammatory and antioxidant actions against acetic acid-induced ulcerative colitis in rats. Materials and methods: Pretreatment with OLM-M at a dose of (5mg/kg, p.o.), 7days before induction of colitis, continued till the 4th day. The severity of colitis in rats was assessed by macroscopic and histopathological examinations. Results: The results suggested that OLM-M attenuated the macroscopic and microscopicolonic damage induced by acetic acid when administrated before induction of colitis (prophylactic effects). Conclusion: OLM-M may be effective in prophylaxis of ulcerative colitis through targeting RAS.