<p>The mechanism of action of Mesalamine is unknown, but appears to be topical rather than systemic. Mucosal production of Arachidonic Acid metabolites, both through the cyclooxygenase pathways, that is, prostanoids, and through the lipoxygenase pathways, that is, leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic infammatory bowel disease. Mesalamine diminishes infammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon.</p>