Mesalamine, also known as Mesalazine or 5-aminosalicylic acid (5-ASA), is an anti-inflammatory drug used to treat inflammation of the digestive tract (Crohn's disease) and mild to moderate ulcerative colitis. Mesalazine is a bowel-specific aminosalicylate drug that is metabolized in the gut and has its predominant actions there, thereby having fewer systemic side effects. As a derivative of salicylic acid, 5-ASA is also an antioxidant that traps free radicals, which are potentially damaging by-products of metabolism. Although the mechanism of action of mesalazine is not fully understood, it appears to be topical rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalazine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon. Mesalazine is used for the treatment of active ulcerative proctitis.

p-Aminophenol is an active metabolite of paracetamol. p-Aminophenol is conjugated with arachidonic acid by fatty acid amide hydrolase to form AM404. AM404 exerts effect through cannabinoid receptors. p- Aminophenol is a nephrotoxic metabolite of paracetamol and phenacetin. It causes acute renal proximal tubular necrosis after administration to rats. p-Aminophenol may cause skin sensitization, dermatitis. p-Aminophenol is a synthetic dye used in hair coloring.

Aniline is a toxic organic compound consisting of a phenyl group attached to an amino group. It is the prototypical aromatic amine. Aniline and its derivatives are very important for the synthesis of chemical products such as dyes, resins, and medicines. The main use of aniline is in the manufacture of precursors to polyurethane. Aniline is a carcinogen that is considered to induce tumors secondary to hemosiderosis as a consequence of methemoglobinemia. Aniline is classified as Group 3, not classifiable as to its carcinogenicity in humans (IARC, 480 1987b). Aniline occurs naturally in some foods (i.e., corn, grains, beans, and tea), but the larger source of exposure is in industrial settings. Lifetime permissible daily exposure (PDE) for aniline is 720 ug/day. Simple anilines such as aniline and monosubstituted anilines are known to disappear from the environment mainly via biodegradation.

Mesalamine, also known as Mesalazine or 5-aminosalicylic acid (5-ASA), is an anti-inflammatory drug used to treat inflammation of the digestive tract (Crohn's disease) and mild to moderate ulcerative colitis. Mesalazine is a bowel-specific aminosalicylate drug that is metabolized in the gut and has its predominant actions there, thereby having fewer systemic side effects. As a derivative of salicylic acid, 5-ASA is also an antioxidant that traps free radicals, which are potentially damaging by-products of metabolism. Although the mechanism of action of mesalazine is not fully understood, it appears to be topical rather than systemic. Mucosal production of arachidonic acid metabolites, both through the cyclooxygenase pathways, i.e., prostanoids, and through the lipoxygenase pathways, i.e., leukotrienes and hydroxyeicosatetraenoic acids, is increased in patients with chronic inflammatory bowel disease, and it is possible that mesalazine diminishes inflammation by blocking cyclooxygenase and inhibiting prostaglandin production in the colon. Mesalazine is used for the treatment of active ulcerative proctitis.