title: A potent chain-breaking antioxidant activity of the cardiovascular drug dipyridamole.
abstract: The antioxidant properties of the antithrombotic drug dipyridamole have been studied using lipid oxidation assays based on the generation of peroxy radicals by azo compounds. Dipyridamole was observed to prevent both peroxidation of arachidonic acid micelles in aqueous solution and peroxidation of methyl linoleate in organic solvents; in contrast to vitamin E, dipyridamole was found to scavenge both hydrophilic and hydrophobic radicals. The rate constant for the reaction of dipyridamole with methyl linoleate peroxyl radicals at 37 degrees C was calculated as 2 x 10(6) M-1s-1, in comparison to 1 x 10(6) M-1s-1 of vitamin E under the same conditions. The antioxidant efficiency of the drug was confirmed in experiments with radiolysis-induced oxidation and through measurements of malondialdehyde production and diene formation. As a result of radical scavenging, a relatively stable dipyridamole radical was formed that could be detected by electron spin resonance spectroscopy. The particular antioxidant properties of dipyridamole may explain the vasodilating and antiplatelet effects of this cardiovascular drug.
authors.affiliation: Institute of I Clinical Medicine, University La Sapienza, Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Iuliano
authors.forename: J Z
authors.initials: JZ
authors.lastname: Pedersen
authors.forename: G
authors.initials: G
authors.lastname: Rotilio
authors.forename: D
authors.initials: D
authors.lastname: Ferro
authors.forename: F
authors.initials: F
authors.lastname: Violi
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D016718:Arachidonic Acid / Q000378:metabolism; D004176:Dipyridamole / Q000494:pharmacology*; D005609:Free Radicals; D007700:Kinetics; D008041:Linoleic Acids / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D008315:Malondialdehyde / Q000378:metabolism; D008823:Micelles; D010545:Peroxides / Q000378:metabolism; D012997:Solvents; D014810:Vitamin E / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D008041:Linoleic Acids; D008823:Micelles; D010545:Peroxides; D012997:Solvents; D014810:Vitamin E; C005575:methyl linoleate; D016718:Arachidonic Acid; C049375:perhydroxyl radical; D008315:Malondialdehyde; D004176:Dipyridamole