title: [Nitroxides as antioxidants - possibilities of their application in chemoprevention and radioprotection].
abstract: Nitroxides as stabile organic radicals were used initially as spin labels in spectroscopy of electron paramagnetic resonance (EPR) with respect to parameters such as pH of an intercellular environment, oxygenation of cells and tissues, fluidity of biological membranes, conformational state and topography of proteins. Nitroxides have also been used in biology and medicine as contrast agents in magnetic resonance imaging (MRI). When their antioxidant activities were discovered, an era of research on the potential utility of these agents began. Nitroxides can modulate the redox state of the cell by participation in oxidation/reduction reactions. Therefore, they are extensively examined in various models of oxidative stress. The antioxidant effect of nitroxides is a result of their ability to catalyze dismutation of superoxide radical (superoxide dismutase-like activity), inhibit lipid peroxidation, prevent Fenton and Haber-Weiss reactions by oxidation of transition metal ions to a higher oxidative state, and confer catalase-like activity on heme proteins. In the present paper the antioxidative mechanisms of nitroxides are presented. The relation between structure, function and the rate of nitroxide reduction inside cells and tissues is also presented. The application of nitroxides in chemoprevention and radioprotection is discussed.
authors.affiliation: Zakład Badań Struktur Biopolimerów, Katedra Biofizyki Molekularnej, Uniwersytet Łódzki. s.tabaczar@gmail.com
authors.forename: Sabina
authors.initials: S
authors.lastname: Tabaczar
authors.forename: Marcin
authors.initials: M
authors.lastname: Talar
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Gwoździński
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D018890:Chemoprevention; D003497:Cyclic N-Oxides / Q000494:pharmacology*; D006801:Humans; D009589:Nitrogen Oxides / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D013113:Spin Labels
chemical_list: D000975:Antioxidants; D003497:Cyclic N-Oxides; D009589:Nitrogen Oxides; D011837:Radiation-Protective Agents; D013113:Spin Labels; C001803:tempol