"Green tea catechins ameliorates adipose Insulin resistance by improving oxidative stress." - GreenMedInfo Summary

Epidemiological data have suggested that drinking green tea is negatively associated with diabetes. And adipose oxidative stress may have a central role in causing insulin resistance, according to recent findings. The aim of this work is to elucidate a new mechanism for green tea's anti-insulin resistance effect. We used obese KK-ay mouse, high-fat diet induced obese rat and induced insulin resistant 3T3-L1 adipocytes as models. Insulin sensitivity and adipose reactive oxidative species (ROS) level were detected in animal and adipocyte. The oxidative stress assay, glucose uptake ability assay and effect of EGCG on insulin signals were detected. Green tea catechins (GTCs) significantly decreased glucose level and increased glucose tolerance in animals. GTCs reduced ROS content in both model of animal and adipocyte. EGCG attenuated Dexamethasone and TNF-α promoted ROS generation and increased glucose uptake ability. EGCG also decreased JNK phosphorylation and promoted GLUT-4 translocation. EGCG and GTCs could improve adipose insulin resistance, and exact this effect on their ROS scavenging functions.