Carotenoids enhance phosphorylation of Akt and suppress tissue factor activity in human endothelial cells.

Enhanced production of tissue factor has been linked to development of cardiovascular disease due to endothelial activation, resulting in thrombosis of blood vessels. Epidemiological studies reported that diet-derived antioxidants might suppress and/or delay progression of cardiovascular disease. Detailed molecular level studies are needed to understand this effect with prevention as a goal. Water-dispersible forms of various carotenoids (beta-carotene, lutein and lycopene) from natural sources in microemulsion were used to study effects of carotenoids on tissue factor activity in human endothelial cells. All carotenoids studied suppressed tissue factor activity (P<.01) and gene expression in human endothelial cells. Our study also demonstrated that addition of Akt-specific inhibitor reversed the inhibitory effect of carotenoids on tissue factor activity, indicating that carotenoids enhanced phosphorylation of Akt and suppressed tissue factor activity in endothelial cells by this mechanism.