The 80th anniversary of vitamin E: beyond its antioxidant properties.
Molecules provided with an antioxidant function may have additional properties, the latter being sometimes of greater importance than the former. In the last ten years, alpha-tocopherol has revealed precise cellular functions, some of which are independent of its antioxidant/radical scavenging ability. At the posttranslational level, alpha-tocopherol inhibits protein kinase C and 5-lipoxygenase and activates protein phosphatase 2A and diacylglycerol kinase. Some genes (CD36, alpha-TTP, alpha-tropomyosin, and collagenase) are affected by alpha-tocopherol at the transcriptional level. alpha-Tocopherol also induces inhibition of cell proliferation, platelet aggregation and monocyte adhesion. These effects are unrelated to the antioxidant activity of vitamin E, but rather are believed to be a result of specific interactions of vitamin E with components of the cell, e. g. proteins, enzymes and membranes. This review focuses on novel non-antioxidant functions of alpha-tocopherol and discusses the possibility that many of the effects previously attributed to the antioxidant functions can also be explained by non-antioxidant mechanisms.
Ricciarelli
Roberta
R
Institute of Biochemistry and Molecular Biology, University of Berne, Switzerland.
Zingg
Jean-Marc
JM
Azzi
Angelo
A
D000818:Animals; D000975:Antioxidants / Q000266:history / Q000493:pharmacokinetics / Q000494:pharmacology; D001161:Arteriosclerosis / Q000517:prevention & control; D001692:Biological Transport; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D009369:Neoplasms / Q000517:prevention & control; D014810:Vitamin E / Q000266:history / Q000493:pharmacokinetics / Q000494:pharmacology / Q000502:physiology*; D014811:Vitamin E Deficiency / Q000503:physiopathology
D000975:Antioxidants; D014810:Vitamin E