Maslinic acid modulates glycogen metabolism by enhancing the insulin signaling pathway and inhibiting glycogen phosphorylase / 中国天然药物
Chinese Journal of Natural Medicines (English Ed.)
; (6): 259-265, 2014.
Article
in English
| WPRIM (Western Pacific)
| ID: wpr-812267
Responsible library:
WPRO
ABSTRACT
AIM@#To investigate the molecular signaling mechanism by which the plant-derived, pentacyclic triterpene maslinic acid (MA) exerts 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 immunosorbent assay (ELISA) was used to measure the effect of MA on IRβ auto-phosphorylation. Furthermore, the effect of MA on glycogen metabolism was investigated in C57BL/6J mice fed with a high-fat diet (HFD).@*RESULTS@#The results showed that MA exerts anti-diabetic effects by increasing glycogen content and inhibiting glycogen phosphorylase activity in HepG2 cells. Furthermore, MA was shown to induce the phosphorylation level of IRβ-subunit, Akt, and GSK3β. The MA-induced activation of Akt appeared to be specific, since it could be blocked by wortmannin. Finally, MA treatment of mice fed with a high-fat diet reduced the model-associated adiposity and insulin resistance, and increased the accumulated hepatic glycogen content.@*CONCLUSION@#The results suggested that maslinic acid modulates glycogen metabolism by enhancing the insulin signaling pathway and inhibiting glycogen phosphorylase.
Full text:
Available
Database:
WPRIM (Western Pacific)
Main subject:
Triterpenes
/
Drugs, Chinese Herbal
/
Signal Transduction
/
Glycogen Phosphorylase
/
Diabetes Mellitus
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Drug Therapy
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Enzyme Inhibitors
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Hep G2 Cells
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Genetics
/
Glycogen
Limits:
Animals
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Humans
/
Male
Language:
English
Journal:
Chinese Journal of Natural Medicines (English Ed.)
Year:
2014
Document type:
Article