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Journal of Biomedicine and Biotechnology
Volume 2006 (2006), Article ID 31372, 13 pages
http://dx.doi.org/10.1155/JBB/2006/31372
Review Article

Mitochondrial Oxidative Damage in Aging and Alzheimer's Disease: Implications for Mitochondrially Targeted Antioxidant Therapeutics

Neurogenetics Laboratory, Neurological Sciences Institute, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton 97006, OR, USA

Received 8 December 2005; Revised 28 February 2006; Accepted 28 February 2006

Copyright © 2006 P. Hemachandra Reddy. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The overall aim of this article is to review current therapeutic strategies for treating AD, with a focus on mitochondrially targeted antioxidant treatments. Recent advances in molecular, cellular, and animal model studies of AD have revealed that amyloid precursor protein derivatives, including amyloid beta (Aβ) monomers and oligomers, are likely key factors in tau hyperphosphorylation, mitochondrial oxidative damage, inflammatory changes, and synaptic failure in the brain tissue of AD patients. Several therapeutic strategies have been developed to treat AD, including anti-inflammatory, antioxidant, and antiamyloid approaches. Among these, mitochondrial antioxidant therapy has been found to be the most efficacious in reducing pathological changes and in not producing adverse effects; thus, mitochondrial antioxidant therapy is promising as a treatment for AD patients. However, a major limitation in applying mitochondrial antioxidants to AD treatment has been the inability of researchers to enhance antioxidant levels in mitochondria. Recently, however, there has been a breakthrough. Researchers have recently been able to promote the entry of certain antioxidants—including MitoQ, MitoVitE, MitoPBN, MitoPeroxidase, and amino acid and peptide-based SS tetrapeptides—into mitochondria, several hundred-fold more than do natural antioxidants. Once in the mitochondria, they rapidly neutralize free radicals and decrease mitochondrial toxicity. Thus, mitochondrially targeted antioxidants are promising candidates for treating AD patients.