Sesamol induces nitric oxide release from human umbilical vein endothelial cells

Sesamol, which is derived from sesame seed lignans, is reportedly an antioxidant. Nitric oxide (NO), the most important vascular relaxing factor, is regulated in the endothelium. In addition, NO is involved in protecting endothelium and has antiatherosclerotic and antithrombotic activities. The endothelium produces NO through the regulation of both endothelial NO synthase (eNOS) expression and activity in endothelial cells. This study sought to investigate the effect of sesamol on NO released from human umbilical vein endothelial cells (HUVEC) and to examine the expression and activity of eNOS. Sesamol induced NO release from endothelial cells in a dose-dependent manner (from 1 to 10 microM), as measured 24 h after treatment; the expression of the eNOS gene at both transcription and translation levels; and NOS activity in endothelial cells. The content of cGMP was also increased by sesamol through NO signaling. The transcription of eNOS induced by sesamol was confirmed through the activation of PI-3 kinase-Akt (protein kinase B) signaling. The results demonstrate that sesamol induces NOS signaling pathways in HUVEC and suggest a role for sesamol in cardiovascular reactivity in vivo.