Maslinic acid modulates glycogen metabolism by enhancing the insulin signaling pathway and inhibiting glycogen phosphorylase.pdf.pdf

Chinese
Journal of
Natural
Chinese Journal of Natural Medicines 2014, 12(4): 0259−0265 Medicines



Maslinic acid modulates glycogen metabolism by enhancing the
insulin signaling pathway and inhibiting glycogen phosphorylase
LIU Jun1, WANG Xue1, CHEN Yu-Peng1, MAO Li-Fei1, SHANG Jing1,
SUN Hong-Bin2*, ZHANG Lu-Yong 1*
1 State Key Laboratory of Natural Medicines, National Drug Screening Center, China Pharmaceutical University, Nanjing
210009, China;
2 Center for Drug Discovery, College of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
Available online 20 Mar. 2014
[ABSTRACT]
AIM: To investigate the molecular signaling mechanism by which the plant-derived, pentacyclic triterpene maslinic acid (MA) ex-
erts anti-diabetic effects.
METHOD: HepG2 cells were stimulated with various concentrations of MA. The effects of MA on glycogen phosphorylase a
(GPa) activity and the cellular glycogen content were measured. Western blot analyses were performed with anti-insulin receptor β
(IRβ), protein kinase B (also known as Akt), and glycogen synthase kinase-3β(GSK3β) antibodies. Activation status of the insulin
pathway was investigated using phospho-IRβ, as well as phospho-Akt, and phospho-GSK3β antibodies. The specific PI3-kinase
inhibitor wortmannin was added to the cells to analyze the Akt expression. Enzyme-linked