5-Acetylsalicylic acid

5-Acetylsalicylic acid (5-acetyl-2-hydroxybenzoic acid) is a nonsteroidal anti-inflammatory drug.

5-Acetylsalicylic acid (5-ASA) is initially shown to downregulate the inducible cyclooxygenase/prostaglandin E2 (COX-2/PGE2) signalling in mucosa inflammatory cells. Generally 5-ASA decreases the nuclear factor κB (NF-κB) activity induced by TNF-α, modulating the NF-κB inhibitor, IκBα, as well as the NF-κB transcriptional activity induced by IL-1, although it does prevent neither IL-1-induced IκBα degradation nor IL-1-induced nuclear translocation of NF-κB family members. 5-ASA is also found to increase β-catenin expression/phosphorylation and the expression of μ-protocadherin in intestine cells while reducing the expression of Wnt/β-catenin target genes and the activity of the protein phosphatase 2A. 5-ASA enhances PPAR-γ expression/activity in intestine cells and promotes its translocation from the cytoplasm to the nucleus -- this is followed by the induction of the tumour suppressor gene PTEN, the activation of caspases 8 and 3, and the inhibition of antiapoptotic proteins. It induces membranous expression of E-cadherin and increases cell adhesion through inhibition of p-21 activated kinase-1 and modulation of N-glycosylation; Also interferes with the mitogen activated protein kinase and phosphatidylinositol-4,5-bisphosphate 3-kinase/Akt pathways[1].

5-ASA is rapidly adsorbed and extensively acetylated to N-acetyl-5-ASA by the N-acetyltransferase 1 enzyme in intestinal epithelial cells and the liver. It is generally well tolerated and the most common side effects include headache, nausea, and abdominal pain[1].

[1] Cristiana Perrotta, et al. Gastroenterology Research and Practice. 2015.