Oxygen free radical traps for the treatment of ischemia-associated organ injury.

Ischemia and reperfusion can induce an excess of free radicals that cannot be mopped-up by the body's endogenous defense mechanisms. This can lead to a breakdown in protein, lipid and DNA molecules, resulting in potentially irreversible organ damage. Radical traps are currently under development for the prevention of major damage in tissues such as the brain (after a stroke-like episode) and heart (after ischemia and reperfusion). While clinical studies are scant, many compounds have been developed and tested in the laboratory. Most radical traps are effective in a variety of preclinical models and one particular class, the nitrones (which includes NXY-059), has been studied intensively as potential neuroprotectants in acute ischemic stroke. NXY-059 is currently undergoing phase III clinical trials and will be the first compound to test the concept that radical traps may be effective and safe neuroprotectants in acute ischemic stroke.