Dietary supplementation with a low dose of (−)‐ epigallocatechin‐3‐gallate reduces pro‐inflammatory response in peripheral leukocytes of non‐obese type 2 diabetic GK rat

Abstract

(−)‐epigallocatechin‐3‐gallate (EGCG), which is found largely in green tea, is known to eliminate reactive oxygen species and associated oxidant stress in vitro and in cells. However, in vivo mechanisms underlying the effects of EGCG on amelioration of metabolic disorders are not fully understood. In this study, we examined whether dietary supplementation of EGCG reduces inflammatory response in peripheral leukocytes of non‐obese type‐ 2 diabetes animal model, Goto‐Kakizaki (GK) rats. GK rats at nine weeks of age were fed a control high‐fat diet (45 energy% from lard and corn oil) or the high‐fat diet containing 0.1%, 0.2% or 0.5% EGCG (w/w) for 25 weeks. Significantly reduced mRNA level of genes related to inflammatory response (IFN‐ E, IL‐1 fÒ, IL‐18 and CD11s) were found in rats fed the diet containing 0.1% EGCG, but not in those fed diets containing 0.2% or more EGCG as compared with control. These results suggest that supplementation of a low dose of EGCG in GK rats reduces expression of genes involved in inflammation in peripheral leukocytes.