Aegeline from Aegle marmelos stimulates glucose transport via Akt and Rac1 signaling, and contributes to a cytoskeletal rearrangement through PI3K/Rac1

Eur J Pharmacol. 2015 Sep 5:762:419-29. doi: 10.1016/j.ejphar.2015.05.021. Epub 2015 Jun 20.

Abstract

Aegeline is an alkaloidal-amide, isolated from the leaves of Aegle marmelos and have shown antihyperglycemic as well as antidyslipidemic activities in the validated animal models of type 2 diabetes mellitus. Here we delineate, aegeline enhanced GLUT4 translocation mediated 2-deoxy-glucose uptake in both time and concentration-dependent manner. 2-deoxy-glucose uptake was completely stymied by the transport inhibitors (wortmannin and genistein) in C2C12 myotubes. Pharmacological inhibition of Akt (also known as protein kinase B) and Ras-related C3 botulinum toxin substrate 1 (Rac1) suggest that both Akt and Rac1 operate aegeline-stimulated glucose transport via distinct parallel pathways. Moreover, aegeline activates p21 protein-activated kinase 1 (PAK1) and cofilin (an actin polymerization regulator). Rac1 inhibitor (Rac1 inhib II) and PAK1 inhibitor (IPA-3) completely blocked aegeline-induced phosphorylation of cofilin and p21 protein-activated kinase 1 (PAK1). In summary, these findings suggest that aegeline stimulates the glucose transport through Akt and Rac1 dependent distinct parallel pathways and have cytoskeletal roles via stimulation of the PI3-kinase-Rac1-PAK1-cofilin pathway in the skeletal muscle cells. Therefore, multiple targets of aegeline in the improvement of insulin sensitivity of the skeletal muscle cells may be suggested.

Keywords: Aegeline; Aegle marmelos; C2C12 myotubes; Cofilin; Glucose uptake; Insulin resistance.

MeSH terms

  • Actin Cytoskeleton / drug effects
  • Actin Cytoskeleton / metabolism
  • Actins / chemistry
  • Aegle / chemistry*
  • Amides / pharmacology*
  • Animals
  • Cell Line
  • Cytoskeleton / drug effects*
  • Cytoskeleton / metabolism*
  • Dose-Response Relationship, Drug
  • Genistein / pharmacology
  • Glucose / metabolism*
  • Glucose Transporter Type 4 / metabolism
  • Humans
  • Insulin Resistance
  • Mice
  • Muscle Fibers, Skeletal / drug effects
  • Muscle Fibers, Skeletal / metabolism
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / drug effects
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation / drug effects
  • Protein Multimerization / drug effects
  • Protein Structure, Quaternary
  • Protein Transport / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / drug effects*
  • Time Factors
  • p21-Activated Kinases / metabolism
  • rac1 GTP-Binding Protein / metabolism

Substances

  • Actins
  • Amides
  • Glucose Transporter Type 4
  • aegeline
  • Genistein
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • p21-Activated Kinases
  • rac1 GTP-Binding Protein
  • Glucose