title: Cacao liquor procyanidin extract improves glucose tolerance by enhancing GLUT4 translocation and glucose uptake in skeletal muscle.
abstract: Hyperglycaemia and insulin resistance are associated with the increased risk of the metabolic syndrome and other severe health problems. The insulin-sensitive GLUT4 regulates glucose homoeostasis in skeletal muscle and adipose tissue. In this study, we investigated whether cacao liquor procyanidin (CLPr) extract, which contains epicatechin, catechin and other procyanidins, improves glucose tolerance by promoting GLUT4 translocation and enhances glucose uptake in muscle cells. Our results demonstrated that CLPr increased glucose uptake in a dose-dependent manner and promoted GLUT4 translocation to the plasma membrane of L6 myotubes. Oral administration of a single dose of CLPr suppressed the hyperglycaemic response after carbohydrate ingestion, which was accompanied by enhanced GLUT4 translocation in ICR mice. These effects of CLPr were independent of α-glucosidase inhibition in the small intestine. CLPr also promoted GLUT4 translocation in skeletal muscle of C57BL/6 mice fed a CLPr-supplemented diet for 7 d. These results indicate that CLPr is a beneficial food material for improvement of glucose tolerance by promoting GLUT4 translocation to the plasma membrane of skeletal muscle.
authors.affiliation: Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe 657-8501, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Food Science Research Labs, Meiji Co. Ltd, Sakado 350-0289, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Okabe
authors.affiliation: Food Science Research Labs, Meiji Co. Ltd, Sakado 350-0289, Japan.
authors.forename: Midori
authors.initials: M
authors.lastname: Natsume
authors.affiliation: Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Nada-ku, Kobe 657-8501, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ashida
keywords: AMPK, AMP-activated protein kinase; CLPr, cacao liquor procyanidin; Cacao liquor; DMSO, dimethylsulfoxide.; GLUT4; Glucose tolerance; Procyanidins