Effect of vitamin E and vitamin C on the DNA synthesis of human umbilical arterial endothelial cells

Summary

Background Endothelial cell growth and reendothealization after vascular injury protect the vessel wall against endothelial dysfunction which is believed to play a major role in the pathogenesis of atherosclerosis. Aim of the study To investigate a possible protective role of antioxidant vitamins in the present study, the effect of vitamin E (α-tocopherol) alone and in combination with vitamin C on the DNA synthesis of human umbilical arterial endothelial cells (HUAEC) was examined. Furthermore, because oxidized low-density lipoprotein (ox-LDL) is thought to be involved in atherogenesis, the combined effect of vitamin E and vitamin C with ox-LDL and the influence of vitamin-pretreated LDL on HUAEC proliferation were investigated. Methods DNA-synthesis was determined by measurement of [³H]thymidine incorporation into the cell DNA. Results Vitamin E alone and in combination with vitamin C resulted in an increase in [³H]thymidine incorporation into cell DNA, especially in the presence of basic fibroblast growth factor (bFGF). All vitamin-pretreated LDL samples and ox-LDL led to a nearly complete inhibition of endothelial DNA-synthesis. The ox-LDL-induced effect could not be prevented by vitamin E alone nor in combination with vitamin C. Conclusions It seems that once LDL oxidation is in process, vitamin E alone and in combination with vitamin C is ineffective to exert its antioxidative capacity under the conditions used. Thus, vitamin E alone and combined with vitamin C may act as antiatherogens by inducing endothelial cell growth.