Cardamonin Stimulates Glucose Uptake through Translocation of Glucose Transporter-4 in L6 Myotubes

• Published in: Phytotherapy research Vol. 25; no. 8; pp. 1218 - 1224
• Main Authors: Yamamoto, Norio, Kawabata, Kyuichi, Sawada, Keisuke, Ueda, Manabu, Fukuda, Itsuko, Kawasaki, Kengo, Murakami, Akira, Ashida, Hitoshi
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.08.2011; Wiley
• Subjects: Alpinia - chemistry; Alpinia katsumadai; Animals; Biological and medical sciences; Biological Transport - drug effects; cardamonin; Cell Line; Cell Membrane - physiology; Chalcones - pharmacology; General pharmacology; Glucose - metabolism; Glucose Transporter Type 4 - metabolism; glucose transporter-4; glucose uptake; Homeostasis - drug effects; L6 myotubes; Medical sciences; Muscle Fibers, Skeletal - drug effects; Muscle Fibers, Skeletal - metabolism; Muscle, Skeletal - drug effects; Muscle, Skeletal - metabolism; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Rats; Signal Transduction - drug effects; Asia; China; Monocotyledones; Aldose; L6 myotubes; cardamonin; Pharmacognosy; Glucose; Alpinia katsumadai; Medicinal plant; Folk medicine; glucose uptake; Angiospermae; Plant origin; glucose transporter-4; Spermatophyta; Carrier protein; Zingiberaceae
• ISSN: 0951-418X; 1099-1573
• DOI: 10.1002/ptr.3416

Glucose transporter‐4 (GLUT4) is a transmembrane protein that plays a major role in insulin‐mediated glucose transport in muscle and adipocytes. For glucose transport to occur, the GLUT4 protein needs to be translocated from the intracellular pool to the plasma membrane, and certain compounds may enhance this process. The present study investigated the promotion of glucose uptake in differentiated L6 myotubes by cardamonin, isolated from Alpinia katsumadai. Cardamonin increased translocation of GLUT4 to the plasma membrane in L6 cells, but did not activate protein kinase C ζ/λ, Akt, or AMP‐activated protein‐kinase, all of which are known to regulate GLUT4 translocation. The glucose‐uptake‐promoting activity of cardamonin was not lowered by treatment with a phosphatidylinositol 3′‐kinase inhibitor. These results suggest that cardamonin is a promising active compound for maintaining glucose homeostasis, and that it acts via an unknown mechanism that does not involve activation of the downstream insulin signal and AMP‐activated protein kinase. Copyright © 2011 John Wiley & Sons, Ltd.