The protective effects of wine pomace products on the vascular endothelial barrier function

Endothelial dysfunction is associated with cardiovascular diseases and involves a chronic inflammatory process that together with oxidative stress increases the permeability of the vascular endothelium. The aim of this study was to evaluate the role of red and white wine pomace products (rWPPs and wWPPs) in the maintenance of endothelial integrity in hyperglycemia of EA.hy926 endothelial cells. EA.hy926 endothelial cells exposed to hyperglycemia were treated with the in vitro digested fractions of rWPPs and wWPPs. A Real Time Cellular Analysis (RTCA) system was used to evaluate the endothelial monolayer integrity after INF-γ stimulation of pre-treated endothelial cells with the digested fractions. The changes in cell viability, NO, ROS and NOX4 were recorded and actin cytoskeleton and E-cadherin junctions were evaluated by immunofluorescence. All digested fractions prevent the hyperglycemic actions in the cell viability and NO/ROS balance. The inflammatory mediator INF-γ and hyperglycemia caused a decrease in RTCA adhesion of the EA.hy926 endothelial cell monolayer. Pre-treatment with all digested fractions enhanced the EA.hy926 endothelial monolayer integrity and maintained actin cytoskeleton and E-cadherin junctions. These in vitro studies elucidate that the anti-hyperglycemic and anti-inflammatory actions of wine pomace products involve a decrease in ROS production and the stabilization of junction proteins via modulation of VE-cadherin and actin cytoskeleton suggesting a potential prevention of endothelial damage by these natural products.