title: Rofecoxib increases susceptibility of human LDL and membrane lipids to oxidative damage: a mechanism of cardiotoxicity.
abstract: Clinical investigations have demonstrated a relationship between the extended use of rofecoxib and the increased risk for atherothrombotic events. This has led to the removal of rofecoxib from the market and concern over the cardiovascular safety of other cyclooxygenase (COX)-2 selective agents. Experimental findings from independent laboratories now indicate that the cardiotoxicity of rofecoxib may not be a class effect but because of its intrinsic chemical properties. Specifically, rofecoxib has been shown to increase the susceptibility of human low-density lipoprotein and cellular membrane lipids to oxidative modification, a contributing factor to plaque instability and thrombus formation. Independently of COX-2 inhibition, rofecoxib also promoted the nonenzymatic formation of isoprostanes and reactive aldehydes from biologic lipids. The basis for these observations is that rofecoxib alters lipid structure and readily forms a reactive maleic anhydride in the presence of oxygen. By contrast, other selective (celecoxib, valdecoxib) and nonselective (naproxen, diclofenac) inhibitors did not influence rates of low-density lipoprotein and membrane lipid oxidation. We have now further confirmed these findings by demonstrating that the prooxidant activity of rofecoxib can be blocked by the potent antioxidant astaxanthin in homochiral form (all-trans 3S, 3'S). These findings provide a mechanistic rationale for differences in cardiovascular risk among COX-selective inhibitors because of their intrinsic physicochemical properties.
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. rpmason@elucidaresearch.com
authors.forename: R Preston
authors.initials: RP
authors.lastname: Mason
authors.forename: Mary F
authors.initials: MF
authors.lastname: Walter
authors.forename: Hyesun P
authors.initials: HP
authors.lastname: McNulty
authors.forename: Samuel F
authors.initials: SF
authors.lastname: Lockwood
authors.forename: Jungsoo
authors.initials: J
authors.lastname: Byun
authors.forename: Charles A
authors.initials: CA
authors.lastname: Day
authors.forename: Robert F
authors.initials: RF
authors.lastname: Jacob
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000068579:Celecoxib; D008078:Cholesterol, LDL / Q000378:metabolism*; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D006801:Humans; D007783:Lactones / Q000009:adverse effects* / Q000097:blood / Q000737:chemistry / Q000494:pharmacology; D008055:Lipids / Q000737:chemistry; D008563:Membrane Lipids / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology*; D010084:Oxidation-Reduction / Q000187:drug effects; D010743:Phospholipids / Q000378:metabolism; D011720:Pyrazoles / Q000097:blood / Q000494:pharmacology; D013449:Sulfonamides / Q000097:blood / Q000494:pharmacology; D013450:Sulfones / Q000009:adverse effects* / Q000097:blood / Q000737:chemistry / Q000494:pharmacology; D024341:Xanthophylls / Q000494:pharmacology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D008078:Cholesterol, LDL; D052246:Cyclooxygenase 2 Inhibitors; D007783:Lactones; D008055:Lipids; D008563:Membrane Lipids; D010743:Phospholipids; D011720:Pyrazoles; D013449:Sulfonamides; D013450:Sulfones; D024341:Xanthophylls; C116926:rofecoxib; C005948:astaxanthine; D000068579:Celecoxib