Evidence for protective and antioxidant properties of rutin, a natural flavone, against ethanol induced gastric lesions.

This study was designed to determine the ulcer-protecting effects of rutin, a natural flavone, against gastric lesions induced by 50% ethanol, the experimental model related to lesion pathogenesis with production of reactive species. The possible involvement of sulphydryl compounds (SH), neutrophil infiltration, and the capacity of this flavone to restrain the oxidative process produced in the gastric tissue were also investigated. The levels of thiobarbituric acid (TBA, as index of lipid peroxidation), the myeloperoxidase activity (MPO, as a marker of neutrophil infiltration), the content of mucosal sulphydryls (SH) groups and the activity of glutathione peroxidase (GSH-Px, an important antioxidant enzyme) were determined. Pretreatment with the highest dose of rutin (200 mg/kg), 120 min before 50% ethanol, resulted in the most effective necrosis prevention. TBA reactive substances in the gastric mucosa, were increased by ethanol injury, and this increase was inhibited by the administration of 200 mg/kg of rutin. However, the flavonoid was not able to modify the ethanol-induced neutrophil infiltrate expressed as myeloperoxidase activity. Exposure of the gastric mucosa to 50% ethanol induced a significant diminution in gastric non-protein SH content; this parameter also was not modified by the treatment with rutin. GSH-Px activity decreased in the gastric mucosa after ethanol-treatment. In contrast, rutin at all tested doses induced a significant increase in this enzymatic activity, higher than in control group. These results suggest that the gastroprotective effect of rutin in this experimental model appears through an anti-lipoperoxidant effect, and also by enhancement of the anti-oxidant enzymatic (GSH-Px) activity.