The role of reactive oxygen metabolites in ulcerative colitis

Summary: Reactive oxygen metabolites (ROMs) contribute to tissue injury in inflammatory bowel disease. The aim of this study is to examine the role of ROMs in the tissue injury in ulcerative colitis (UC). The study group consisted of 27 patients with UC (14 active, 13 quiescent) and a control group of 10 patients with various anal diseases. We measured the content of malondialdehyde (MDA), superoxide dismutase (SOD), and myeloperoxidase (MPO) in colorectal biopsies. MDA was measured by the thiobarbituric acid assay. SOD and MPO were measured using the nitro blue tetrazolium and o-dianisidine Ulcerative colitis (UC) is a common disorder of unknown etiology. Although the pathogenesis of UC is unknown, multiple inflammatory mediators have bcen implicated as the cause of tissue injury (1,2). A group of chemicals known as reactive oxygen species (ROSs) are believed to be final common mediators of inflammation. These molecules are thought to play a role in both the initiation and the progression of active UC and other inflammatory diseases (3,4). Production of these metabolites has been shown to occur in the gastrointestinal tract (5), and drugs used in the treatment of UC such as azulphidine and 5-aminosalicylic acid (5-ASA) are effective in reducing concentration of ROS (6,7). A specific anti-ROS drug, superoxide dismutase (SOD), has been used with some success in the treatment of UC in an uncontrolled study (8). These findings suggest that ROSs participate in the tissue injury of UC. but the existence of ROSs in thc inflamed colon and their relation to disease activity have not been clearly established. The aims of this study were to determine the concentrations of malondialdehyde (MDA), SOD, and myeloperoxidase (MPO) in intestinal mucosa of UC patients -~ ~. ~~~ ~~~~~~