Epigallocatechin Gallate Attenuate Oxidized Low Density Lipoprotein-induced Endothelial Inflammation

Abstract

Background: Atherosclerosis is an inflammatory disease. Atherogenic lipoproteins cause inflammatory responses to the vascular wall in the early stage of atherogenesis. (-)-Epigallocatechin-3-gallate (EGCG), the main catechin in green tea, has been well known about its benefits in cardiovascular system and anti-oxidant effects. However, its protective effects against oxidized low density lipoprotein (oxLDL) -induced endothelial inflammation still unclear. PURPOSE: In this study, we examined whether EGCG prevents inflammatory responses in endothelial cells caused by oxLDL and to explore the possible mechanism. METHODS: Primary human umbilical vein endothelial cell cultures (HUVECs) incubated with oxLDL were used to explored the anti-inflammatory effects of EGCG. The expression of NF-κBp65, phosphorylated p38 and cycloxygenase -2 (COX-2) was measured by Enzyme-Link Immunosorbent Assay (ELISA), Western blot and immunocytochemistry. Adhesion molecule expression of intercellular adhesion molecule (ICAM), E-selectin and monocyte chemoattractant protein-1(MCP-1) as well as several pro-inflammatory cytokines including interleukin-8 (IL-8), interleukin-6 (IL-6) and Endothelin-1(ET1) were investigated by real-time PCR, ELISA and flow cytometry. RESULTS: Our results showed that oxLDL -induced inflammatory response including activation of NF-kBp65, phosphorylation of P38, expression of COX-2, adhesion molecule (ICAM, E-selectin and MCP-1) and pro-inflammatory cytokines (IL-6, IL8 and ET1) both in mRNA and protein levels. All these parameters were significantly rescued by pretreatment with EGCG. CONCLUSIONS: We demonstrated that EGCG prevent oxLDL-induced inflammatory responses, implying that EGCG has a potential role in the prevention of atherosclerotic vascular disease.