Green Tea Research Today is a free monthly online journal that collates and summarizes the latest research about Green Tea, including details on benefits, antioxidants, weight loss, diet, side effects. | ||||||||
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(-)-Epigallocatechin-3-gallate inhibits monocyte chemotactic protein-1 expression in endothelial cells via blocking NF-kappaB signaling.Hong MH, Kim MH, Chang HJ, Kim NH, Shin BA, Ahn BW, Jung YD Chonnam University Research Institute of Medical Sciences, Chonnam National University Medical School, Kwangju, 501-190, South Korea. Monocyte chemotactic protein-1 (MCP-1) is a potent chemoattractant for monocytes and plays a key role in various inflammatory responses, including atherosclerosis. In this study, we examined the effect of (-)-epigallocatechin-3-gallate (EGCG), a major green tea catechin, on the expression of MCP-1 in human endothelial ECV304 cells. EGCG markedly inhibited the phorbol 12-myristate 13-acetate (PMA)-induced MCP-1 mRNA and protein levels in a dose-dependent manner. EGCG was also found to reduce the MCP-1 transcriptional activity. The upregulation of MCP-1 by PMA was significantly inhibited by blockade of P38 mitogen-activated protein kinase (MAPK) and NF-kappaB, but not by blockade of extracellular-signal-regulated kinase and c-Jun N-terminal kinase pathway. Furthermore, The PMA-induced p38 MAPK and NF-kappaB activation were obviously attenuated after pretreating ECV304 cells with EGCG. The conditioned media from the endothelial ECV304 cells treated with PMA could remarkably stimulate the migration of THP-1 monocytes and this effect was partially abrogated by MCP-1 neutralizing antibodies. Moreover, the media from the EGCG-pretreated ECV304 cells lost the stimulatory activity for THP-1 migration. These results suggest that EGCG may exert an anti-inflammatory effect in endothelial cells by controlling MCP-1 expression, at least in part, mediated through the suppression of p38 MAPK and NF-kappaB activation. Published 23 April 2007 in Life Sci, 80(21): 1957-65.
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