Vitamin E inhibits lipid peroxidation-induced adhesion molecule expression in endothelial cells and decreases soluble cell adhesion molecules in healthy subjects

Objective: In a combination of in vivo and in vitro studies, we investigated mechanisms via which α-tocopherol, a lipid soluble form of vitamin E, can directly affect endothelial activation as induced by H2O2 and TNFα. Methods: We measured effects of α-tocopherol on H2O2-induced lipid peroxidation as determined with a fluorescent C-11 BODIPY581/591 probe and on adhesion molecule expression in cultured endothelial cells. In 20 healthy volunteers treated with increasing doses of α-tocopherol up to 800 IU/ml for 12 weeks, plasma levels of soluble cell adhesion molecules (sCAMs) and C-reactive protein were measured. Results: We showed that α-tocopherol protects cultured endothelial cells against H2O2-induced lipid peroxidation, while TNFα did not induce lipid peroxidation. Moreover, α-tocopherol attenuated H2O2-, but not TNFα-induced increases in adhesion molecule expression. In healthy persons, α-tocopherol decreased plasma levels of sE-selectin from 65±6 to 60±6 ng/ml (P=0.002), sVCAM from 893±31 to 853±23 ng/ml (P=0.022), and sICAM from 483±21 to 463±16 ng/ml (P=0.048). C-Reactive protein, as a sensitive marker of low grade inflammation, was not significantly affected. Conclusion: α-Tocopherol specifically inhibits lipid peroxidation-induced endothelial activation in vitro. The observed vitamin E-induced decrease in sCAMs in control subjects suggests that lipid peroxidation can take place in healthy individuals. Although vitamin E supplementation may be especially effective in specific groups of patients exposed to increased oxidative stress, our study suggests that vitamin E supplementation can be of benefit in healthy individuals as well. © 2003 European Society of Cardiology. Published by Elsevier Science B.V. All rights reserved.
Chemicals/CAS: alpha tocopherol, 1406-18-4, 1406-70-8, 52225-20-4, 58-95-7, 59-02-9; C reactive protein, 9007-41-4; carbon 11, 14333-33-6; endothelial leukocyte adhesion molecule 1, 128875-25-2; hydrogen peroxide, 7722-84-1; intercellular adhesion molecule 1, 126547-89-5; alpha-Tocopherol, 59-02-9; Antioxidants; C-Reactive Protein, 9007-41-4; Cell Adhesion Molecules; Hydrogen Peroxide, 7722-84-1; Tumor Necrosis Factor-alpha