ANTIOXIDANT PROPERTIES OF TICLOPIDINE ON HUMAN LOW-DENSITY-LIPOPROTEIN OXIDATION

We found that ticlopidine, at therapeutically relevant concentrations (2.5-10 mu M), but not aspirin nor salicylate, significantly counterac ted copper-driven human LDL oxidation, Ticlopidine, at 5 and 10 mu M, was also antioxidant on peroxyl radical-induced LDL oxidation; yet it was ineffectual an thiol and ascorbate oxidation mediated by peroxyl r adicals themselves, suggesting that drug antioxidant capacity is someh ow related to the lipoprotein nature of the oxidizable substrate, but not to radical scavenging, The drug could not indeed react with the st able free radical 1,1-diphenyl-2-pycrylhydrazyl, nor had apparent meta l complexing-inactivating activity, Thus, ticlopidine has antioxidant effects on LDL oxidation, which, together with its anti-platelet activ ity, could confer peculiar antiatherogenic properties to the drug in v ivo. (C) 1998 Federation of European Biochemical Societies.