Vitamin E-modulated gene expression associated with ROS generation

Although the beneficial effects of vitamin E on reactive oxygen species (ROS)-related diseases, such as cardiovascular disease (CVD), have been suggested by epidemiological and animal studies, clinical trials have failed to confirm the efficacy of vitamin E. Vitamin E has a defined role as an antioxidant. Recent studies indicate non-antioxidant roles of vitamin E serving as a regulator of gene/protein expression and enzyme inhibitor. Vitamin E may control ROS generation possibly in both antioxidant-dependent and independent manners, since vitamin E has shown inhibitory effects on activities and expression of ROS generating enzymes. However, the effects of vitamin E appear to depend on microenvironment, such as its concentration and the presence of oxidants/antioxidants. The objective of this article is to review the roles of vitamin E, in particular vitamin E-modulated gene expression, for better understanding the molecular mechanisms of vitamin E and for preventive and therapeutic strategies of ROS-related diseases. (C) 2009 Elsevier Ltd. All rights reserved.