Epigallocatechin-3-gallate Impairs Chemokine Production in Human Colon Epithelial Cell Lines

Abstract

A major component in green tea, epigallocatechin-3-gallate (EGCG), is reported to interfere with different steps of a number of inflammatory pathways. After oral administration, EGCG is retained in the gastrointestinal tract, where it is thought to exert preventive functions against inflammatory bowel disease and colon cancer. In this study, the human colon adenocarcinoma cell lines HT29 and T84 were used to investigate the effect of EGCG on intestinal inflammation. HT29 and T84 cells were stimulated with tumor necrosis factor (TNF)-␣ to induce the inflammatory condition and to trigger the inflammatory cascade in vitro and treated with EGCG to study its effect on inflammatory processes. The secretion of the chemokines interleukin (IL)-8, macrophage inflammatory protein (MIP)-3␣, and prostaglandin E 2 (PGE 2 ) was determined by enzyme-linked immunosorbent assay. The gene expression level was measured by quantitative real-time polymerase chain reaction. Treatment of TNF-␣-stimulated HT29 cells with EGCG dose-dependently inhibited the synthesis of IL-8, MIP-3␣, and PGE 2 . Treatment with EGCG also inhibited the production of IL-8 and MIP-3␣ in TNF-␣-stimulated T84 cells. Gene expression analysis in both HT29 and T84 cells revealed that EGCG down-regulates genes involved in inflammatory pathways. This study shows that EGCG acts broadly on the production of chemokines and PGE 2 in the chemokine and eicosanoid pathways of colon epithelial cells. Therefore, EGCG might prove useful for the prevention and/or attenuation of colonic disorders.

Inflammatory Bowel Disease: Mechanisms, Redox Considerations, and Therapeutic Targets

“…The same flavonoid had previously been shown to inhibit TNFa-induced increase of IL-8 and prostaglandin (PG) E2 production in human colonadenocarcinoma cell lines (204).…”

Prospective Cohort Study of Green Tea Consumption and Colorectal Cancer Risk in Women

“…Tea catechins have strong antioxidant activity, which is about 25 to 100 times more potent than vitamins E and C (11). Epigallocatechin-3-gallate has been shown to attenuate the inflammatory response in human colon adenocarcinoma cell lines by inhibiting the production of chemokines and prostaglandin E 2 (12). In addition to the antioxidant and antiinflammatory activities, recent research has proposed many other possible mechanisms for the cancer-inhibitory effects of green tea, including modulation of signal transduction pathways, which leads to inhibition of cell proliferation and transformation, induction of apoptosis and cell cycle arrest, and inhibition of tumor invasion and angiogenesis (1,13,14).…”

Cancer chemoprevention and chemotherapy: Dietary polyphenols and signalling pathways

“…Punicalagin and EGCG impeded the activation of TNF-a-induced COX-2 protein expression or chemokines and PGE2 production, respectively in colon cancer cells [134,140]. Similarly, mangiferin blocked TNFinduced NF-jB activation and NF-jB-dependent genes such as ICAM1 and COX2 through inhibition of IKK activation and subsequent blocking of phosphorylation and degradation of IjBa [141].…”