Endothelial expression of cell adhesion molecules (CAM) including VCAM-1, E-selectin, and PECAM-1plays a leading role in atherosclerosis. Phenolic flavones have been shown to have an anti-inflammatory property. This study examines whether 3',4'-dimethoxy-7-hydroxyflavone (methoxyflavone) and 2',3',7-trihydroxyflavone (hydroxyflavone) inhibited monocyte adhesion to TNF-
-activatedendothelium via reduction of CAM expression in human umbilical vein endothelial cells (HUVEC). Instimulated HUVEC the expression of VCAM-1 and E-selectin was enhanced with increasing mRNAlevels. Methoxyflavone markedly interfered with the THP-1 monocyte adhesion to TNF-
-stimulatedHUVEC. At concentrations of
25
M, methoxyflavone blocked the induction of VCAM-1 but notthat of E-selectin on the activated HUVEC. Immunocytochemical staining showed that methoxyflavonemodestly inhibited PECAM-1 expression induced by TNF-
. In contrast, hydroxyflavone minimallyinhibited TNF-
-stimulated E-selectin expression without affecting VCAM-1 level. The inhibitory effectof methoxyflavone on THP-1 adhesion to HUVEC appears to be greater than that of hydroxyflavone,most likely due to a greater inhibition of CAM expression. Thus, some flavone derivatives containingmethoxy groups may have therapeutic potential attenuating inflammatory response-related atherosclerosis.Keywords: Flavone derivatives; tumor necrosis-
; cell adhesion molecules; endothelium