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.