Effect of the antioxidant alpha-lipoic acid on apoptosis in human umbilical vein endothelial cells induced by high glucose.

High glucose plays an important role in the pathogenesis of atherosclerosis. In this study, we assessed the effects of high glucose on human umbilical vein endothelial cell (HUVEC) apoptosis. Additionally, we investigated whether alpha-lipoic acid, an antioxidant, prevents high glucose-induced apoptosis of HUVECs. HUVECs were treated with high glucose in the presence or absence of alpha-lipoic acid. Treatment of HUVECs with high glucose changed cell morphology and induced DNA fragmentation, leading to apoptosis. Apoptosis was induced by high glucose in a dose-and time-dependent fashion. High glucose markedly elevated Bax, and decreased NF-kappaB and Bcl-2 expression. Most importantly, pretreatment with alpha-lipoic acid protected against high glucose-induced apoptosis in the endothelial cells. alpha-Lipoic acid significantly promoted the expression of NF-kappaB while decreasing the expression of Bax and the activities of caspase-3 and-9 without significantly affecting the Bcl-2 level. Our data suggest that high glucose induces apoptosis in endothelial cells. alpha-Lipoic acid effectively attenuates high glucose-induced endothelial cell apoptosis. These findings provide new perspectives on the role of alpha-lipoic acid in cardiovascular disease.