Gallates inhibit cytokine-induced nuclear translocation of NF-kappa B and expression of leukocyte adhesion molecules in vascular endothelial cells

Gallates (gallic acid esters) belong to the class of phenolic compounds, wh ich are abundant in red wine. In this study, we show that gallates can inhi bit cytokine-induced activation of nuclear factor kappa B (NF-kappa B) and thereby reduce expression of endothelial-leukocyte adhesion molecules in cu ltured human umbilical vein endothelial cells (HUVECs). Pretreatment of HUV ECs with ethyl gallate (3 to 10 mu mol/L) significantly suppressed interleu kin-1 alpha (IL-1 alpha)- or tumor necrosis factor-alpha (TNF-alpha)- induc ed mRNA and cell-surface expression of vascular cell adhesion molecule 1 (V CAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin, which w as associated with reduced adhesion of leukocytes to HUVECs. Gel shift assa ys with the NF-kappa B consensus sequence showed the decreased densities of the shifted bands in gallate-treated HUVECs. Furthermore, gallate pretreat ment inhibited cytokine-induced transcription of a fusion gene, which consi sted of 4 repeats of the NF-kappa B consensus sequence and the luciferase r eporter gene. Immunoblot analysis of nuclear extracts and whole-cell lysate s demonstrated the decreased amounts of NF-kappa B p65 in nuclei but equal amounts of inhibitor-kappa B alpha (I-kappa B alpha) in whole-cell lysates of ethyl gallate-treated HUVECs. Incubation of the nuclear extracts from cy tokine-activated HUVECs with ethyl gallate did not affect the NF-kappa B sh ifted bands induced by cytokines in gel shift assays. Taken together, these data demonstrate that ethyl gallate can inhibit cytokine-induced nuclear t ranslocation of NF-kappa B p65 by way of a mechanism independent of I-kappa B alpha degradation and thereby suppress expression of VCAM-I, ICAM-1, and E-selectin, which was associated with reduced adhesion of leukocytes. Thes e results in vitro demonstrate that gallates can exhibit anti-inflammatory properties hv blocking activation of NF-kappa B and suggest that these natu ral compounds, abundant in red wine, may play important roles in the preven tion of atherosclerosis and inflammatory responses in vivo.