Vitamin E: beyond antioxidant function.
Vitamin E, a potent peroxyl radical scavenger, is a chain-breaking antioxidant that prevents the propagation of free radical damage in biological membranes. We consider the evidence for potential sites in cellular metabolism and signal transduction where vitamin E may have a structure-specific role in addition to its antioxidant function. The roles of tocopherol-binding proteins in cellular trafficking of vitamin E, especially the incorporation of RRR-alpha-tocopherol into nascent lipoproteins, and the delivery of RRR-alpha-tocopherol to the nucleus are considered. We discuss the functions of vitamin E both in the inhibition and potentiation of arachidonic acid metabolism. The interactions of vitamin E during cell proliferation and differentiation are also evaluated. These functions of vitamin E raise new questions and represent new and exciting areas for research in cell regulation with physiologic implications.
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D016718:Arachidonic Acid / Q000378:metabolism; D002352:Carrier Proteins / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism; D011493:Protein Kinase C / Q000502:physiology; D014810:Vitamin E / Q000494:pharmacology*
D000975:Antioxidants; D002352:Carrier Proteins; D016328:NF-kappa B; C017763:alpha-tocopherol transfer protein; D014810:Vitamin E; D016718:Arachidonic Acid; D011493:Protein Kinase C