Reactive oxygen: its sources and significance in Alzheimer disease

Over the past decade, oxidative stress has been established as the earliest cytological feature of Alzheimer disease and an attractive therapeutic target. The major challenges now are establishing the source of the reactive oxygen and what oxidative stress tells us about the etiology of Alzheimer disease. These are complex issues since a variety of enzymatic and nonenzymatic processes are involved in reactive oxygen formation and damage to macromolecules. In this review, we consider disease mechanisms that show the greatest promise for future research.