In vitro activity: Aspirin inhibits the activation of NF-kappa B, thus prevents the degradation of the NF-kappa B inhibitor, I kappa B, and therefore NF-kappa B is retained in the cytosol. Aspirin also inhibits NF-kappa B-dependent transcription from the Ig kappa enhancer and the human immunodeficiency virus (HIV) long terminal repeat (LTR) in transfected T cells. Aspirin and salicylate are mediated in part by their specific inhibition of IKK-beta, thereby preventing activation by NF-kappaB of genes involved in the pathogenesis of the inflammatory response. Aspirin is protective against neurotoxicity elicited by the excitatory amino acid glutamate in rat primary neuronal cultures and hippocampal slices. Aspirin triggers transcellular biosynthesis of a previously unrecognized class of eicosanoidsduring coincubations of human umbilical vein endothelial cells (HUVEC) and neutrophils [polymorphonuclear leukocytes (PMN)]. Aspirin evokes a unique class of eicosanoids formed by acetylated PGHS-2 and 5-lipoxygenase interactions. Aspirin treatment inhibits the phosphorylation of IRS-1 at Ser307 as well as the phosphorylation of JNK, c-Jun, and degradation of IkappaBalpha in 3T3-L1 and Hep G2 cells treated with tumor necrosis factor (TNF)-alpha. Aspirin treatment inhibits phosphorylation of Akt and the mammalian target of rapamycin (but not extracellular regulated kinase or PKCzeta) in response to TNF-alpha. Aspirin rescues insulin-induced glucose uptake in 3T3-L1 adipocytes pretreated with TNF-alpha.

Cell Assay: Chondrocytes are isolated from articular cartilage of donors with no articular disease. Unstimulated and interleukin 1 (IL-1) stimulated chondrocytes are used as models to study the effects of drugs on COX-1 and COX-2. Cells are incubated with vehicle or drugs (Asprin); supernatants are removed and the level of prostaglandin E2 (PGE2) in each sample is determined by enzyme immunoassay. IC50s are calculated from the reduction in PGE2 content by different concentrations of the test substance by linear regression analysis.

Science. 1994 Aug 12;265(5174):956-9; Nature. 1998 Nov 5;396(6706):77-80.