Gastroprotective effect of rutin against indomethacin-induced ulcers in rats

Several reports have indicated that indomethacin-induced gastropathy is mediated through generation of free radicals, neutrophil infiltration and disturbance in nitric oxide production. Rutin is a potent antioxidant flavonoid. Recently, rutin was reported to inhibit neutrophil infiltration and to modulate nitric oxide production in gastric mucosa. Therefore, the aim of this study was to investigate the protective effect of rutin against indomethacin-induced gastric injury. Accordingly, four groups of rats were used. The first three groups were injected orally with vehicle, rutin (200 mg/kg) and indomethacin (48 mg/kg) respectively. The fourth group was injected with rutin 1 hr before indomethacin. Animals were killed after 6 hr of indomethacin administration. Gastric juice acidity and gastric injury were evaluated directly. Moreover, the activities of myeloperoxidase, superoxide dismutase and the contents of reduced glutathione, thiobarbituric acid reactive substance and total nitrite/nitrate (as a marker of nitric oxide production) were determined in mucosal tissues. Indomethacin increased gastric ulcer index, gastric myeloperoxidase activity, gastric acidity and thiobarbituric acid reactive substance contents compared with control. On the other hand, indomethacin decreased glutathione, nitrite/nitrate contents and superoxide dismutase activity. Histopathological examination of the stomachs of indomethacin-treated rats revealed degenerative changes in gastric tissues. Pre-treatment with rutin protected gastric tissues against indomethacin-induced gastropathy as demonstrated from reduction in the ulcer index, attenuation of histopathological changes and amelioration of the altered oxidative stress and biochemical parameters. These results indicate that rutin has a protective effect against indomethacin-induced gastropathy probably through inhibiting neutrophil infiltration, suppression of oxidative stress generation and replenishing nitrite/nitrate levels regardless of gastric acidity.