Defense against free radicals has therapeutic implications

Abstract

Like aspirin, "if oxygen were being introduced as a new drug, it would probably fail to pass the stringent guidelines imposed by the Food and Drug Administration," says Joe M. McCord, PhD, who goes on to explain: "The minimum effective dose is too close to a dangerous, toxic dose." But there are defenses, and these offer promise of new therapeutic approaches to myocardial infarction (MI) and for preventing ischemic damage during organ transplantation. Ninety-eight percent of molecular oxygen is completely reduced to water in the process of respiration, says McCord, who is professor and chair of the Department of Biochemistry, University of South Alabama College of Medicine, Mobile. The other 2%, he says, turns into potentially toxic "free radicals"—molecules with heightened chemical reactivity because of the single, unpaired electron in their outer shell. "The bottom line here is that if you do anything less than the complete, full reduction of