Exp Mol Med.  2003 Apr;35(2):136-139.

Epigallocatechin gallate, a constituent of green tea, suppresses cytokine-induced pancreatic beta-cell damage

• Han MK

Abstract

Cytokines produced by immune cells infiltrating pancreatic islets have been implicated as one of the important mediators of beta-cell destruction in insulin-dependent diabetes mellitus. In this study, the protective effects of epigallocatechin gallate (EGCG) on cytokine-induced beta-cell destruction were investigated. EGCG effectively protected IL-1beta and IFN-g-mediated cytotoxicity in insulinoma cell line (RINm5F). EGCG induced a significant reduction in IL-1b and IFN-gamma-induced nitric oxide (NO) production and reduced levels of the inducible form of NO synthase (iNOS) mRNA and protein levels on RINm5F cells. The molecular mechanism by which EGCG inhibited iNOS gene expression appeared to involve the inhibition of NF-kB activation. These findings revealed EGCG as a possible therapeutic agent for the prevention of diabetes mellitus progression.

Keyword

cytokine; epigallocatechin gallate; NF-kappaB; nitric oxide

MeSH Terms

Animals
Blotting, Western
Catechin/*analogs & derivatives/*pharmacology
Cell Line
Cell Survival/drug effects
Cytokines/*antagonists & inhibitors/pharmacology
Interferon Type II/antagonists & inhibitors/pharmacology
Interleukin-1/antagonists & inhibitors/pharmacology
Islets of Langerhans/cytology/*drug effects
Nitric-Oxide Synthase/metabolism
Nitrites/metabolism
Tea/*chemistry