Sesamol regulates plasminogen activator gene expression in cultured endothelial cells: a potential effect on the fibrinolytic system

Sesamol is a component in the nutritional makeup of sesame that was identified as an antioxidant. In recent years, the importance of the plasminogen activator (PA) and its adjustment factor, plasminogen activator inhibitor-1 (PAI-1), in the prevention of atherosclerosis has gradually received recognition. The objective of this in vitro study was to demonstrate the effects of sesamol on PA and PAI-1. We also compared the effects of sesamol with two well-known antioxidants, vitamins C and E, by using human umbilical vein endothelial cells as an experimental model and by treating them with the above-mentioned three nutrients with doses up to 100 μmol/L. After 24 h, cells and cultural medium were collected for analysis. The concentrations of tissue PA (tPA), urokinase PA (uPA) and PAI-1 were measured by an enzymatic immunity method. Northern blot method was used to analyze the expression of mRNA of these three types of proteins. The results showed that sesamol increased the production of uPA and tPA significantly and also up-regulated the mRNA expressions of these proteins. On the other hand, vitamins C and E could induce tPA but not uPA. As for PAI-1, none of the nutrients induced any evident response. These findings suggest that the overall vascular fibrinolytic capacity may be enhanced by using sesamol to regulate PA gene expression.