Vitamin E and cancer prevention: recent advances and future potentials.
Many animal and in vitro experiments have shown that the supplementation of diet with vitamin E within a certain dose range reduced the risk of chemical- and radiation-induced cancers. In vitro studies revealed that alpha-tocopheryl succinate (TS) induced differentiation and growth-inhibition in certain animal and human tumor cells in culture, whereas alpha-tocopherol (alpha-T), alpha-tocopheryl acetate (alpha-TA) and alpha-tocopheryl nicotinate (alpha-TN) were ineffective, alpha-TS also reduced basal and ligand-stimulated adenylate cyclase activity, and expression of c-myc and H-ras oncogenes in certain tumor cells in culture. The relative efficacy of various forms of vitamin E in cancer prevention in animal or human models has not been evaluated. Human epidemiologic studies utilizing retrospective and prospective case-control experimental designs are not suitable for evaluating the role of vitamin E in cancer prevention due to several inherent problems associated with these methodologies. Intervention trials utilizing vitamin E with appropriate biological and statistical rationales are most suitable for testing the role of vitamin E in cancer prevention in humans. Some human trials utilizing vitamin E alone or in combination with other nutrients are in progress.
Prasad
K N
KN
Department of Radiology, School of Medicine, University of Colorado Health Sciences Center, Denver 80262.
Edwards-Prasad
J
J
D000818:Animals; D006224:Cricetinae; D004347:Drug Interactions; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008297:Male; D051379:Mice; D009369:Neoplasms / Q000517:prevention & control*; D051381:Rats; D014407:Tumor Cells, Cultured; D014810:Vitamin E / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*
D014810:Vitamin E