Protection by metal complexes with SOD-mimetic activity against oxidative gastric injury induced by indometacin and ethanol in rats

We have investigated the protective effect or oral administration of copper and manganese complexes with superoxide dismutase (SOD)-mimetic activity against oxidative gastric mucosal injury induced by the non-steroidal antiinflammatory drug indometacin with ethanol in the rat. The total area of the gastric lesions and lipid peroxidation were significantly increased 1 h after oral administration of indometacin (15 mg/kg) and ethanol, indicating in acute oxidative injury. The activities of SOD, catalase (CAT), glutathione-S-transferase (GST) and glutathione content were significantly decreased in the gastric mucosa by indometacin plus ethanol. Manganese or copper complexes showed SOD-mimetic activity. Pretreatment with these complexes protected against gastric mucosal lesions and decreased lipid peroxides, as well as attenuating the decrease in the activities or SOD, CAT and GST in gastric mucosa. These findings suggest that active oxygen species and lipid peroxidation play an important role in the pathogenesis of gastric mucosal injury induced by indometacin. In addition, we have shown that Mn and Cu complexes have gastroprotective properties against ulceration induced by indometacin plus ethanol. The present results suggest that appropriate copper or manganese complex supplementation may potentially provide prophylaxis or therapy for some pathologies associated with excessive free radical production and inhibited SOD activity.