5-Aminosalicylic Acid

5-Aminosalicylic acid (5-ASA) is a non-steroidal anti-inflammatory drug (NSAID) and an active metabolite of sulfasalazine (Item No. 15025), balsalazide (Item No. 18680), and olsalazine (Item No. 23661).{8427} It is formed from these prodrugs by bacterial azoreductases in the intestinal lumen.{30379} 5-ASA selectively inhibits COX-2 over COX-1 in isolated human whole blood (IC50s = 61 and 410 µM, respectively). It inhibits hemoglobin- and hydrogen peroxide-induced lipid peroxidation in a cell-free assay (IC50 = 50 µM).{64642} 5-ASA (100 µM) also inhibits the synthesis of leukotriene B4 (LTB4; Item No. 20110) in isolated human mucosal cells.{8429} Formulations containing 5-ASA have been used in the treatment of inflammatory bowel disease (IBD) and ulcerative colitis.