Effect of the anti-oxidant probucol on soluble thrombomodulin (sTM) in hypercholesterolemic rabbits

Introduction Thrombomodulin is an integral endothelial cell membrane protein, exists not only on the surface of endothelial cells but also as soluble fragments circulating in plasma. Probucol has anti-oxidant properties as well as cholesterol-lowering effects and may affect soluble thrombomodulin (sTM). Methods Sixteen rabbits fed with high-cholesterol diet for 8 weeks were randomly divided into two groups: (1) high-cholesterol group (n = 8): maintained high-cholesterol diet; (2) probucol group (n = 8): the same diet plus probucol for 6 weeks. Control group (n = 8) was fed with normal diet for 14 weeks. The levels of sTM and oxidized low-density lipoprotein (OX-LDL) were measured using ELISA. Results There were atherosclerotic lesions in aortas and intimal thickness significantly increased in high-cholesterol group. Probucol significantly reduced the lesion area (56.4% ± 9.8% vs 82.5% ± 10.5%) and decreased the intimal thickness (44.65 ± 7.25 μm vs 72.21 ± 8.32) as compared with high-cholesterol group, all P < 0.01. Probucol decreased the level of OX-LDL and sTM as compared with high-cholesterol group, all P < 0.05. Conclusions Probucol retarded the plaques formation may relate to decrease plasma OX-LDL and sTM concentration, which may improve endothelial function in hypercholesterolemic rabbit.