Gastroprotective effect of simvastatin against indomethacin-induced gastric ulcer in rats: Role of nitric oxide and prostaglandins

Abstract

This study investigated the possible mechanisms underlying the gastroprotective effect of simvastatin against indomethacin-induced gastric ulcer in rats. Rats were randomly assigned to vehicle-, simvastatin-, simvastatin + l-arginine- and simvastatin + N(G)-nitro- l-arginine methyl ester (L-NAME)-pretreated groups for two weeks. Pyloric ligation was performed for the collection of gastric juice, and gastric ulceration was induced by a single intraperitoneal injection of indomethacin (30 mg/kg). Gastric juice parameters (total acid output, pepsin activity and mucin concentration) were determined. The stomachs tissues were used for determination of gastric mucosal lipid peroxides, superoxide dismutase, catalase, total nitrites and prostaglandin E 2 levels. Pretreatment with simvastatin (10 mg/kg, orally, for 2 weeks) caused significant reduction in gastric mucosal lesions and lipid peroxides associated with a significant increase in gastric juice mucin concentration. Simvastatin significantly increased the gastric mucosal total nitrite and prostaglandin E 2 levels. Additionally, simvastatin attenuated the elevations in gastric mucosal superoxide dismutase observed with indomethacin. The gastroprotective effect afforded by simvastatin was significantly augmented by coadministration with l-arginine (a nitric oxide precursor) and inhibited by coadministration with L-NAME (a nitric oxide synthase inhibitor). Results confirm a gastroprotective effect for simvastatin, and indicate that the anti-ulcer effect of simvastatin is mediated by scavenging free radicals, increasing nitric oxide and prostaglandin E 2 levels, and increasing gastric juice mucin production. We conclude that simvastatin represents a more suitable antihyperlipidemic therapy for patients who are at risk of gastric ulcers that were induced by the use of nonsteroidal anti-inflammatory drugs (NSAIDs).