Curcumin inhibits LPS-induced CCL2 expression via JNK pathway in C6 rat astrocytoma cells

Cell Mol Neurobiol. 2012 Aug;32(6):1003-10. doi: 10.1007/s10571-012-9816-4. Epub 2012 Mar 13.

Abstract

The important role of neuroinflammation in many chronic and acute pathological conditions of the central nervous system is widely recognized. Curcumin is a major component of turmeric and reportedly has anti-inflammatory and anti-oxidant effects. This study investigated the inhibitory effect of curcumin on lipopolysacharide (LPS)-induced chemokine CCL2 (or monocyte chemoattractant protein-1, MCP-1) production and whether the effect is mediated by mitogen-activated protein kinases (MAPKs) in the rat astrocytoma cell C6. We observed that LPS (1 μg/ml) induced the upregulation of CCL2 mRNA and protein in C6. Treatment with curcumin (2.5, 10, and 25 μM) decreased the expression of CCL2 mRNA and protein in a dose-dependent manner under treatment with LPS. Additionally, the c-jun N-terminal kinase (JNK) inhibitor (SP600125) dose-dependently inhibited LPS-induced CCL2 upregulation, whereas the MAPK kinase (MEK) inhibitor (PD98059) only had a mild effect and the p38 MAPK inhibitor (SB203580) had no effect. Finally, western blot showed that LPS induced rapid JNK activation and curcumin reduced LPS-induced phosphoJNK (pJNK) expression at 30 min after LPS stimulation. These data suggest that the anti-neuroinflammatory effect of curcumin relates to the downregulation of CCL2 expression through the JNK pathway in astrocytoma cells, which indicates a possible benefit from the use of curcumin in the treatment of neuroinflammation-associated disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytoma / enzymology*
  • Astrocytoma / genetics
  • Astrocytoma / pathology
  • Cell Line, Tumor
  • Chemokine CCL2 / genetics
  • Chemokine CCL2 / metabolism*
  • Curcumin / pharmacology*
  • Dose-Response Relationship, Drug
  • Enzyme Activation / drug effects
  • Gene Expression Regulation, Neoplastic / drug effects
  • JNK Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Lipopolysaccharides / pharmacology*
  • MAP Kinase Signaling System / drug effects*
  • Protein Kinase Inhibitors / pharmacology
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Rats
  • Up-Regulation / drug effects
  • Up-Regulation / genetics

Substances

  • Ccl2 protein, rat
  • Chemokine CCL2
  • Lipopolysaccharides
  • Protein Kinase Inhibitors
  • RNA, Messenger
  • JNK Mitogen-Activated Protein Kinases
  • Curcumin