Inhibitive effect of purple sweet potato leaf extract and its components on cell adhesion and inflammatory response in human aortic endothelial cells

This study investigated the effects of purple sweet potato leaf extract (PSPLE) and its components, cyanidin and quercetin, on human aortic endothelial cells (HAECs) during the inflammatory process. HAECs were pretreated with 100 mu g/mL PSPLE or 10 mu M quercetin, cyanidin or aspirin for 18 h followed by TNF-alpha (2 ng/mL) for 6 h, and U937 cell adhesion was determined. Adhesion molecule expression and CD40 were evaluated; NF kappa B p65 protein localization and DNA binding were assessed. PSPLE, aspirin, cyanidin and quercetin significantly inhibited TNF-alpha-induced monocyte-endothelial cell adhesion (p < 0.05). Cyanidin, quercetin and PSPLE also significantly attenuated VCAM-1, IL-8 and CD40 expression, and quercetin significantly attenuated ICAM-1 and E-selectin expression (p < 0.05). Significant reductions in NF kappa B expression and DNA binding by aspirin, cyanidin and quercetin were also observed in addition to decreased expression of ERK1, ERK2 and p38 MAPK (p < 0.05). Thus, PSPLE and its components, cyanidin and quercetin, have anti-inflammatory effects through modulation of NF kappa B and MAPK signaling. Further in vivo studies are necessary to explore the possible therapeutic effects of PSPLE on atherosclerosis.