Oxidative stress and antioxidants in intestinal disease.

Oxidative injury caused by free radicals is an important cause of tissue injury now recognized to occur in inflammation, ischemia and by the action of xenobiotics. It is also recognized to induce gene mutation and promote carcinogenesis. In this review the general concept of nett free radical injury counterbalanced by antioxidants is discussed as oxidative stress. The role of oxidative stress in intestinal ischemia, radiation enteritis, inflammatory bowel disease and the promotion of gastric and colorectal cancer is discussed. The data for the role of oxidative stress in the pathogenesis of ischemic, inflammatory and radiation induced disease are strong, but interventional studies with antioxidants have shown only weak beneficial effects in the above diseases. Therefore the role of antioxidants in the therapy of gastrointestinal diseases remains controversial and should be the subject of controlled trials.