alpha-tocopherol protects the peroxidative modification of LDL to be recognized by LDL receptors

Background: Peroxidatively modified low-density lipoprotein (LDL) may contr ibute to the atherosclerotic process; therefore, protecting LDL against per oxidation may reduce or retard the progression of atherosclerosis. We evalu ated the effect of alpha-tocopherol on copper-catalyzed LDL peroxidative mo dification. Methods: The protective effects of alpha-tocopherol on copper-c atalyzed LDL peroxidative modification were examined by measurement of the concentration of lipid hydroperoxides in LDL and by the provision of LDL ch olesterol to lymphocytes via the LDL receptor-mediated pathway. Results: Th e measurement of concentration of lipid hydroperoxides in LDL showed that a lpha-tocopherol inhibited the peroxidative modification of LDL. Also, alpha -tocopherol preserved the ability of LDL to be recognized by LDL receptors in peripheral blood lymphocytes to the same extent as native LDL. Conclusio n: These findings indicate that alpha-tocopherol may protect LDL against pe roxidative modification, maintaining its ability to act as a ligand for LDL receptors in vivo.