Suppression of CC chemokine production and HMVEC chemotaxis by green tea extract

Abstract

In the present study, we tested the efficacy of polyphenol‐containing green tea extract (GTE) in regulating CC chemokine production in human rheumatoid arthritis (RA) synovial fibroblasts and rat adjuvant‐induced arthritis (AIA), and human microvascular endothelial cell (HMVEC) chemotaxis. Pre‐incubation of RA synovial fibroblasts with GTE (2.5–40 μg/ml) inhibited interleukin‐1β (IL‐1β)‐induced monocyte chemoattractant protein (MCP)‐1/CCL‐2 and Regulated upon activation normal T cell expressed and secreted (RANTES)/CCL5 production with an IC50 values of ~16.4 and ~7.5 μg/ml, respectively. Interestingly, GTE pre‐incubation significantly inhibited RANTES/CCL5‐induced HMVEC chemotaxis in a dose‐dependent manner. GTE administration (200 mg/kg/day p.o.) for 10 days markedly ameliorated AIA in rats as reflected by a decrease in articular index and ankle circumference in the GTE‐treated group by ~28% and ~38%, respectively, when compared to the PBS group. Suppression of arthritis was accompanied by a decrease in joint MCP‐1/CCL2 level and serum RANTES/CCL5 level. Inhibition of CC chemokine production and chemotaxis by GTE may be one potential mechanism to limit the overall inflammation and joint destruction in RA.