Vicenin-2 and scolymoside inhibit high-glucose-induced vascular inflammation in vitro and in vivo

The vascular inflammatory process has been suggested to play a key role in the initiation and progression of atherosclerosis, a major complication of diabetes mellitus. Thus, in this study, we attempted to determine whether 2 structurally related flavonoids found in Cyclopia subternata, vicenin-2 and scolymoside, can suppress high-glucose (HG)-induced vascular inflammatory processes in human umbilical vein endothelial cells (HUVECs) and mice. The effects of vicenin-2 and scolymoside on HG-induced vascular inflammation were determined by measuring vascular permeability, leukocyte adhesion and migration, cell adhesion molecule (CAM) expression levels, and reactive oxygen species (ROS) formation. In addition, the anti-inflammation mechanism was investigated using immunofluorescence staining and Western blotting. The data showed that HG markedly increased vascular permeability, monocyte adhesion, expression of CAMs, formation of reactive oxygen species (ROS), and activation of nuclear factor (NF)-kappa B. Remarkably, pretreatment with vicenin-2 and scolymoside attenuated all of the above-mentioned vascular inflammatory effects of HG. HG-induced vascular inflammatory responses are critical events underlying the development of various diabetic complications; therefore, our results suggest that vicenin-2 and scolymoside have significant therapeutic benefits against diabetic complications and atherosclerosis.