Vitamin E. Neurochemistry and implications for neurodegeneration in Parkinson's disease

Recently there has been a great deal of interest in the potential therapeutic use of supplemental vitamin E in amelioration of diseases of the nervous system. Even though many studies have provided encouraging results, the mechanism of any beneficial effect remains elusive. Experimental studies suggest that the presence of high levels of vitamin E in tissues prior to injury is essential for biological efficacy because administration of the vitamin after insult is often ineffective. The rationale for this phenomenon is unknown at present. Some of the remaining areas of investigation include the biochemical interaction of vitamin E with other biological antioxidant substances such as vitamin C and sulfhydryl compounds; the relative potencies of different molecular forms of tocopherols, such as trienols and various optical isomers; and the optimal dosage and mode of administration of the most potent tocopherol molecule. Future research on these and other topics will shed more light on the effective use of vitamin E in neurodegeneration.