Planta Med 2009; 75(10): 1141-1143
DOI: 10.1055/s-0029-1185481
Pharmacology
Letter
© Georg Thieme Verlag KG Stuttgart · New York

Effects of Maslinic Acid, a Natural Triterpene, on Glycogen Metabolism in Cultured Cortical Astrocytes

Teng Guan1 , Yunman Li1 , Hongbin Sun2 , Xuzhen Tang1 , Yisong Qian1
  • 1Department of Physiology, China Pharmaceutical University, Nanjing, P. R. China
  • 2Center of Drug Discovery, China Pharmaceutical University, Nanjing, P. R. China
Further Information

Publication History

received December 15, 2008 revised February 8, 2009

accepted February 11, 2009

Publication Date:
16 March 2009 (online)

Abstract

Maslinic acid (2-α,3-β-dihydroxyolean-12-en-28-oic acid) is a triterpenoid compound present in plants of Olea europaea. In the present study, we investigated the effect of maslinic acid on astrocytic glycogen metabolism. Glycogen phosphorylase (GP) activity in homogenates of cultured astrocytes was analyzed, and maslinic acid exhibited GP inhibition with an IC50 value of 5.7 µM. Moreover, the influence of maslinic acid on glycogen synthesis and glycogenolysis was also investigated. Pre-incubation with maslinic acid dose-dependently increased cellular glycogen content and prevented the excessive glycogenolysis induced by norepinephrine. In conclusion, maslinic acid is suggested to be a potent inhibitor of astrocytic glycogen phosphorylase.

References

  • 1 Hutchinson D S, Summers R J, Gibbs M E. Energy metabolism and memory processing: role of glucose transport and glycogen in responses to adrenoceptor activation in the chicken.  Brain Res Bull. 2008;  76 224-234
  • 2 Gibbs M E, Hutchinson D, Hertz L. Astrocytic involvement in learning and memory consolidation.  Neurosci Biobehav Rev. 2008;  32 927-944
  • 3 Abdelmalik P A, Shannon P, Yiu A, Liang P, Adamchik Y, Weisspapir M, Samoilova M, Burnham W M, Carlen P L. Hypoglycemic seizures during transient hypoglycemia exacerbate hippocampal dysfunction.  Neurobiol Dis. 2007;  26 646-660
  • 4 Pfeiffer-Guglielmi B, Francke M, Reichenbach A, Hamprecht B. Glycogen phosphorylase isozymes and energy metabolism in the rat peripheral nervous system – an immunocytochemical study.  Brain Res. 2007;  1136 20-27
  • 5 Wen X, Sun H, Liu J, Wu G, Zhang L, Wu X, Ni P. Pentacyclic triterpenes. Part 1: the first examples of naturally occurring pentacyclic triterpenes as a new class of inhibitors of glycogen phosphorylases.  Bioorg Med Chem Lett. 2005;  15 4944-4948
  • 6 Wen X, Zhang P, Liu J, Zhang L, Wu X, Ni P, Sun H. Pentacyclic triterpenes. Part 2: synthesis and biological evaluation of maslinic acid derivatives as glycogen phosphorylase inhibitors.  Bioorg Med Chem Lett. 2006;  16 722-726
  • 7 Wen X, Sun H, Liu J, Cheng K, Zhang P, Zhang L, Hao J, Zhang L, Ni P, Zographos S E, Leonidas D D, Alexacou K M, Gimisis T, Hayes J M, Oikonomakos N G. Naturally occurring pentacyclic triterpenes as inhibitors of glycogen phosphorylase: synthesis, structure-activity relationships, and x-ray crystallographic studies.  J Med Chem. 2008;  51 3540-3554
  • 8 Aiston S, Coghlan M P, Agius L. Inactivation of phosphorylase is a major component of the mechanism by which insulin stimulates hepatic glycogen synthesis.  Eur J Biochem. 2003;  270 2773-2781
  • 9 Hevor T K, Delorme P. Biochemical and ultrastructural study of glycogen in cultured astrocytes submitted to the convulsant methionine sulfoximine.  Glia. 1991;  4 64-69
  • 10 McCarthy K D, de Vellis J. Preparation of separate astroglial and oligodendroglial cell cultures from rat cerebral tissue.  J Cell Biol. 1980;  85 890-902
  • 11 Bergmeyer H U. GPa assay. Methods of enzymatic analysis, 4th edition. New York; Academic Press 1974: 293-295
  • 12 Neese J W, Duncan P, Bayse D D. Development and evaluation of a hexokinase/glucose-6-phosphate dehydrogenase procedure for use as a national glucose reference method.  Clin Chem. 1974;  20 878
  • 13 Lowry O H, Rosebrough N J, Farr A L, Randall R J. Protein measurement with the Folin phenol reagent.  J Biol Chem. 1951;  193 264-275

Prof. Dr. Yunman Li

Department of Physiology
China Pharmaceutical University

24 Tongjiaxiang street

210009 Nanjing

People's Republic of China

Phone: + 86 25 85 32 53 83

Fax: + 86 25 85 32 53 83

Email: liyunmancpu@hotmail.com