Free radicals in inflammatory bowel diseases pathophysiology and therapeutic implications.

Inflammatory bowel diseases are characterized by the accumulation of granulocytes and monocytes/macrophages at the site of inflammation. Activation of these cells leads to the release of degradative enzymes, e.g., proteinases and glycosidases, and the production of reactive oxygen metabolites. This has been shown both in animal models of experimental intestinal injury, and in human inflammatory bowel disease. Scavenging of oxygen radicals protected tissue from damage in experimental inflammation models. Human studies with specific oxygen radical scavengers are rare, preliminary results appear promising. The fact that the aminosalicylates used in the treatment of inflammatory bowel disease are potent antioxidants underscores the important role of reactive oxygen metabolites in this setting.