Search results
Results from the WOW.Com Content Network
Aspirin acts as an acetylating agent where an acetyl group is covalently attached to a serine residue in the active site of the COX enzyme. [1] This makes aspirin different from other NSAIDs (such as diclofenac and ibuprofen), which are reversible inhibitors; aspirin creates an allosteric change in the structure of the COX enzyme. [2]
The existing nonsteroidal anti-inflammatory drugs differ in their relative specificities for COX-2 and COX-1; while aspirin and ibuprofen inhibit COX-2 and COX-1 enzymes, other NSAIDs appear to have partial COX-2 specificity, particularly meloxicam . [39] Aspirin is ≈170-fold more potent in inhibiting COX-1 than COX-2. [40]
COX-2 is an enzyme facultatively expressed in inflammation, and it is inhibition of COX-2 that produces the desirable effects of NSAIDs. [125] When nonselective COX-1/COX-2 inhibitors (such as aspirin, ibuprofen, and naproxen) lower stomach prostaglandin levels, ulcers of the stomach or duodenum and internal bleeding can result. [126]
Aspirin-modified COX-2 (aka prostaglandin-endoperoxide synthase 2 or PTGS2) produces epi-lipoxins, most of which are anti-inflammatory. [44] [verification needed] [45] Newer NSAID drugs, COX-2 inhibitors (coxibs), have been developed to inhibit only COX-2, with the intent to reduce the incidence of gastrointestinal side effects. [17] Several ...
Before the confirmation of COX-2 existence, the Dupont company had developed a compound, DuP-697, that was potent in many anti-inflammatory assays but did not have the ulcerogenic effects of NSAIDs. Once the COX-2 enzyme was identified, Dup-697 became the building-block for synthesis of COX-2 inhibitors.
COX is a common target for anti-inflammatory drugs. The most significant difference between the isoenzymes, which allows for selective inhibition, is the substitution of isoleucine at position 523 in COX-1 with valine in COX-2. The smaller Val 523 residue in COX-2 allows access to a hydrophobic side-pocket in the enzyme (which Ile 523 ...
Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit prostaglandin production by PTGS1 (COX-1) and PTGS2 (COX-2). NSAIDs selective for inhibition of PTGS2 (COX-2) are less likely than traditional drugs to cause gastrointestinal adverse effects, but could cause cardiovascular events, such as heart failure, myocardial infarction, and stroke.
COX-1 is inhibited by nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin. Thromboxane A2, the major product of COX-1 in platelets, induces platelet aggregation. [20] [21] The inhibition of COX-1 is sufficient to explain why low dose aspirin is effective at reducing cardiac events.