白血球在血管管壁的黏附與移行是動脈粥狀硬化進展的早期主要因素，且血管內皮細胞表現的黏附因子在動脈粥狀硬化過程中扮演重要角色。抗氧化物具有抑制細胞黏附分子表現，進而可降低動脈粥狀硬化的發生作用。故本研究主要探討具有抗氧化的紫色蕃薯葉萃曲液及其主要成份cyanidin與quercetin，對於前發炎因子腫瘤壞死因子α刺激人類主動脈內皮細胞之黏附因子與NF-κB表現的影響。將人類主動脈內皮細胞預先以紫色蕃薯葉萃取物（100 μg/mL）、quercetin（10μM）和cyanidin（10μM）處理18小時，可顯著性減少人類單核球細胞株U937的黏附。而使用細胞酵素連結免疫吸光分析法，顯示紫色蕃薯葉萃取物及其主要成份quercetin和cyanidin可顯著降低血管黏附分子表現分別達（VCAM-1）54％、28％、37％，但只有紫色蕃薯葉萃取物及Quercetin顯著降低細胞間黏附分子（ICAM-1）表現分別達19％、38％表現；對內皮細胞黏附因子（E-selectin）的表現則不具影響。並且紫色蕃薯葉萃取物降低NF-κB p65 表現，可能造成抑制NF-κB表現，進而影響黏附因此可能在延緩動脈粥狀硬化與發炎反應因子表現。
The adhesion and migration of circulating leukocytes into the vessel wall is an early event in atherogenesis and the expression of cell adhesion molecules by the arterial endothelium plays a major role during atherogenesis. Antioxidants have been proposed to inhibit the expression of adhesion molecules and there by attenuate the processes leading to atherosclerosis. In this study, the effects of antioxidant extract from purple sweet potato leaves and its major components cyanidin and quercetin on the expression of adhesion molecules and NF-κB in tumor necrosis factor-a (TNF-a) treated human aortic endothelial cells (HAEC) were investigated. Pretreated of HAEC with purple sweet potato leaves (100 μg/mL), quercetin (10 μM), cyaniding (10 μM) for 18h significantly suppressed cellular binding between the human monocytic leukemic cell line-U937 and TNF-α-stimulated HAEC by using an in vitro binding assay.
Cell-enzyme-linked immunosorbent assay (Cell-ELISA) and immunoblot analysis showed that pretreated of HAEC with purple sweet potato leaves extracts (100 μg/mL) , quercetin (10 μM) and cyanidin (10 μM) for 18h significantly attenuated vascular cell adhesion molecule-1 (VCAM-1)expression by 54％,28％and 37％respectively. But only intercellular cell adhesion molecule-1(ICAM-1) expression by 19％and 38％recpectively. But only purple sweet potato leaves extracts and quercetin signifieantly attenuated intercellular cell. However, there had no effect on expression of endothelial cell E-selectin. Meanwhile, purple sweet potato leaves extracts significantly decreased the expression of NF-κB p65 witch may decrease the activity of NF-κB and further influence on the expression of adhesion molecules and there by attenuate the atherosclerosis and inflammatory responses.
