Sulphasalazine is a potent inhibitor of prostaglandin 15-hydroxydehydrogenase: possible basis for therapeutic action in ulcerative colitis.

Sulphasalazine is a potent and selective inhibitor in vitro of prostaglandin 15-hydroxydehydrogenase in rabbit colon (ID50 = 50 micrometer) and in several other organs of different species, but does not inhibit prostaglandin delta-13 reductase or microsomal prostaglandin synthesis from arachidonic acid. It is suggested that this action may underly the therapeutic usefulness of sulphasalazine in ulcerative colitis for the prevention of relapse.