[Salazosulfapyridine and 5-aminosalicylic acid agents for the treatment of ulcerative colitis].

: Sulfasalazine and 5-aminosalicylic acid are very useful therapeutic agents for the treatment of the inflammatory bowel disease, such as ulcerative colitis or Crohn's disease. However, the mechanism of action of the aminosalicylates remains obscure. Recently, many studies about their mechanism have been performed. As a result, aminosalicylates have been identified to have several antiinflammatory pathways: (1) alterations in eicosanoid metabolism of arachidonic acid; particularly inhibition of leukotrien B4 production, (2)free radical scavengers; scavenging reactive oxygen metabolites or nitric oxide (3)immunologic suppression; inhibition of HLA-DR expression on the intestinal epithelial cells, inflammatory cytokine(IL-1 and IL-2) production, adhesion molecule expression, platelet-activating factor release, or histamine release from mast cell, and so on.