ABSTRACT
A high flux of reactive oxygen-derived species (ROS) can rapidly deplete their level in the tissue. Nitroxide’s protective activity has been studied using physical, chemical, biochemical, and cellular means of insult which initiate injurious processes mediated by ROS. Nitroxides, sometimes denoted nitroxyls or aminoxyls, constitute a unique and unusual class of antioxidants. As nitroxides differ in size, charge, and lipophilicity, efforts were made to select or synthesize specific derivatives in order to achieve desired localization inside cells and optimal activity. The activity of nitroxides and their respective hydroxylamines is reflected by their inhibitory effect on oxidation of proteins, lipids, and DNA. The biological activity of nitroxides has been demonstrated for bacterial and mammalian cells. The protective activity of nitroxides has been studied in several experimental models of laboratory animals. By undergoing one-electron transfer reactions, nitroxides are readily reduced to hydroxylamines or oxidized to oxo-ammonium cations.
