Lipophilic antioxidants in neurodegenerative diseases

Oxidative stress is commonly involved in the pathogenesis of various neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. Therefore, lipophilic antioxidants, such as vitamin A, carotinoids, vitamin E, coenzyme Q10, docosahexaenoic acid and eicosapentaenoic acid, have received increasing attention as therapeutic and preventive intervention for neurodegenerative diseases. Although difficulties exist with clinical studies due to the nature of the long-standing progression of neurodegenerative diseases, findings in cell and animal models, as well as biomarker studies have implied a relationship between lipophilic antioxidants and neurodegeneration. By reviewing current findings and their implication in neurodegenerative diseases, we conclude that although none of these lipophilic antioxidants have yet provided clear-cut clinical evidence toward beneficial effects in neurodegenerative diseases, they could demonstrate neuroprotection in cellular and/or animal studies. Results from future multidisciplinary studies with optimization of factors including drug dosage, delivery route and chemical structure may provide us with novel treatments for neurodegenerative diseases using lipophilic antioxidants.