[The role of free radical scavengers in gastrointestinal diseases].

Be it ever so complex the natural antioxidant scavenger system of the organism, the protection provided by it seems to be inappropriate in certain diseases of the gastrointestinal mucus membrane, such as chronic inflammation, immune- and malignant diseases of the bowel. Despite the wide range of therapeutic attempts, the treatment of these diseases has not yet been solved, and the anti-inflammatory-, immunomodulatory-, cytostatic drugs currently used, have several side effects. Therefore, the so called natural- and synthetic antioxidants have been more widely employed for additional and adjuvant treatment. It also has become clear that the direct free radical scavenging effect and/or the membrane protection play an important role in the action mechanism of several old-established drugs. The recent report lists those natural and synthetic antioxidants which have been successfully employed in the clinical treatment of bowel diseases. Among the natural antioxidants, a protective effect of vitamins A, C and E have been demonstrated in the treatment of gastroduodenal ulcer and gastric cancer. Among the synthetic antioxidants, 5-amino-salicylic acid was the most effective drug in the treatment of chronic inflammations of the bowel. With getting the more precise knowledge about details of free radical reactions and with clearing up their role in pathological processes, it is possible to develop new and effective synthetic antioxidants, and widely employ them therapeutically.