Effects of GE on oral glucose tolerance (OGT) in C57BL/6J mice fed a high-fat diet or normal diet. GE concentrations were 60, 120, 240 mg/kg/day. Metformin (MET) was used as positive control. Blood glucose was measured 30 minutes before glucose administration (−30 min) and every 30 minutes after glucose administration (0, 30, 60, 90, 120 min). Values expressed are means ± S.D of triplicate measurements (n=6 per group).