Free radicals as mediators of toxicity in Alzheimer's disease: a review and hypothesis.

Recent research has increasingly suggested a central role for free radical induced tissue damage in the pathogenesis of Alzheimer's disease (AD). In this paper we review evidence for the interaction between free radicals and other major factors/metabolic areas which have also been implicated in AD, including beta-amyloidosis, inflammatory cytokines, mitochondrial dysfunction and metal ions/homocysteine. We hypothesize that free radicals and antioxidants should not be considered in isolation in the aetiology and treatment of AD. It is the reciprocal induction and self-amplifying interplay between all of the above factors which is important in the pathogenesis of this disorder, and to which multi-pharmacological therapeutic strategies should be directed.