Protective effects of idebenone on vascular endothelial cells against toxicity induced by oxidatively modified low density lipoprotein.

We examined the protective effects of idebenone, 6-(10-hydroxydecyl)-2,3-dimethoxy-5-methyl-1,4-benzoquinone, on the cytotoxicity of oxidatively-modified low density lipoprotein (oxLDL), using cultured vascular endothelial cells from fetal bovine aorta. When the cells were incubated with idebenone, the toxicity of oxLDL was inhibited dose-dependently (10(-7)-10(-5) M). When cells were preincubated with idebenone, the toxicity of oxLDL was inhibited only at a high concentration (10(-5) M). However, idebenone had no significant effects on copper-induced modification of LDL. The protective effects of idebenone on oxLDL-induced endothelial toxicity may be beneficial for the inhibition of the development of atherosclerosis in the brain and other arterial systems.