Blueberry (Vaccinium virgatum Aiton) Leaf Infusion Ameliorates Insulin Resistance in Mice Fed a High-fat, High-sucrose Diet

Abstract

Blueberry (Vaccinium virgatum Aiton) leaf extract (BLEx) has attracted attention as a beneficial food component. Here, we examined the effect of dietary BLEx on glucose and lipid metabolism in mice fed a high-fat, high-sucrose diet (HFHSD). Growth parameter data showed that 3% BLEx slightly reduced body weight and adipose tissue weight accompanied by inhibition of HFHSD-induced enlargement of adipocytes. Liver weight was significantly reduced in the 3% BLEx group secondary to reduction of lipid accumulation in the hepatocytes. HFHSD-induced augmentation of fasting serum glucose levels was ameliorated by 3% BLEx. HFHSD-induced increase of fasting serum insulin level, Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) and Quantitative Insulin Sensitivity Check Index (QUICKI) also tended to be ameliorated. Oral glucose tolerance tests (OGTTs) revealed that 3% BLEx normalized HFHSD-induced elevation of the area under the curve for serum glucose, whereas dietary BLEx, even for the 3% dose, did not have a suppressive effect on the serum glucose change after OGTT. Taken together, these observations suggest that BLEx is a promising agent for the prevention of HFHSD-induced insulin resistance.