Anti-atherosclerotic Activity of Platycodin D Derived from Roots of Platycodon grandiflorum in Human Endothelial Cells

This study examined the effects of platycodin D (PD), a triterpene saponin from the the root of Platycodon grandiflorum A.DC on human umbilical vein endothelial cells (HUVECs) in vitro, which were pre-treated with PD (0.01, 0.15, 0.25 mg/mL), respectively, and treated with 50 mg/L oxidized low-density lipoprotein (oxLDL). The levels of nitric oxide (NO) and malonaldehyde (MAD) in the culture medium, vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1) mRNA expression in endothelium cells and the adhesion of monocytes to endothelial cells were measured. The results showed that PD increased NO concentration and decreased MDA level induced by oxLDL in the medium of endothelial cells. Moreover, PD significantly inhibited the oxLDL-induced increase in monocyte adhesion to endothelial cells as well as decreasing mRNA expression levels of VCAM-1 and ICAM-1 on these cells. Based on these results, it is suggested that PD is a promising anti-atherosclerotic activity, which is at least in part the result of its increasing NO concentration, reducing the oxLDL-induced cell adhesion molecule expression in endothelial cells and the endothelial adhesion to monocytes.