[Epigallocatechin gallate attenuates the expression of regulated upon activation normal T cell expressed and secreted induced by lipopolysaccharide in human retinal endothelial cells].

ABSTRACT

The present study was undertaken to determine the effect of epigallocatechin gallate (EGCG) on lipopolysaccharide (LPS)-induced production of inflammatory chemokine regulated upon activation normal T cell expressed and secreted (RANTES) in human retinal endothelial cells (HRECs) and to explore the underlying regulatory mechanism. HRECs were stimulated with LPS in the presence or absence of EGCG at various concentrations (100, 50, 25, 12.5, 6.25 µmol/L). The optimum concentration of drug was determined by a real-time cell-electronic sensing (RT-CES) system, and MTS chromatometry was used to detect the toxicity of LPS and EGCG on HRECs. RANTES production in the culture supernatant was measured by ELISA. The expression levels of Akt and phosphorylated Akt were examined by Western blot assay. The result showed that LPS markedly stimulated RANTES secretion from HRECs. EGCG treatment significantly suppressed LPS-induced RANTES secretion in a dose-dependent manner. Furthermore, EGCG exhibited a dose-dependent inhibitory effect on LPS-induced phosphorylation of Akt. Taken together, our data suggest that EGCG suppresses LPS-induced RANTES secretion, possibly via inhibiting Akt phosphorylation in HRECs.