Epigallocatechin-3-O-gallate inhibits TNFα-induced monocyte chemotactic protein-1 production from vascular endothelial cells

Monocyte chemotactic protein-1 (MCP-1) plays a pivotal role in the recruitment of monocytes and thus in the development of inflammatory cardiovascular diseases. Epigallocatechin-3-O-gallate (EGCG), the major catechin derived from green tea, has multiple beneficial effects to reduce cardiovascular disease but the effects of EGCG on vascular endothelial MCP-1 production is not known. In this study, we investigated the mechanisms by which EGCG may inhibit tumor necrosis factor-alpha (TNF alpha)-induced MCP-1 production in bovine coronary artery endothelial cells. TNFa increased MCP-1 production in both a concentration and time-dependent manner. Inhibitors of phosphatidylinositol-3-OH kinase (PI-3 kinase), LY294002 and wortmannin, decreased TNF alpha-induced MCP-1 production. EGCG prevented TNF alpha-mediated MCP-1 production and reduced phosphorylation of Akt (Ser473). In addition, EGCG attenuated TNFa mediated down-regulation of TNFa receptor 1 (TNFR1), but not TNFR2. In conclusion, EGCG inhibited TNF alpha-induced MCP-1 production. Moreover, EGCG inhibited Akt zosphorylation as well as TNF activation of TNFR1, which subsequently resulted in reduced MCP-1 production. These data provide a novel mechanism where the green tea flavonoid, EGCG, could provide direct vascular benefits in inflammatory cardiovascular diseases. (c) 2008 Elsevier Inc. All rights reserved.