Magnolol protects neurons against ischemia injury via the downregulation of p38/MAPK, CHOP and nitrotyrosine

Toxicol Appl Pharmacol. 2014 Sep 15;279(3):294-302. doi: 10.1016/j.taap.2014.07.005. Epub 2014 Jul 16.

Abstract

Magnolol is isolated from the herb Magnolia officinalis, which has been demonstrated to exert pharmacological effects. Our aim was to investigate whether magnolol is able to act as an anti-inflammatory agent that brings about neuroprotection using a global ischemic stroke model and to determine the mechanisms involved. Rats were treated with and without magnolol after ischemia reperfusion brain injury by occlusion of the two common carotid arteries. The inflammatory cytokine production in serum and the volume of infarction in the brain were measured. The proteins present in the brains obtained from the stroke animal model (SAM) and control animal groups with and without magnolol treatment were compared. Magnolol reduces the total infarcted volume by 15% and 30% at dosages of 10 and 30mg/kg, respectively, compared to the untreated SAM group. The levels of acute inflammatory cytokines, including interleukin-1 beta, tumor necrosis factor alpha, and interleukin-6 were attenuated by magnolol. Magnolol was also able to suppress the production of nitrotyrosine, 4-hydroxy-2-nonenal (4-HNE), inducible NO synthase (iNOS), various phosphorylated p38 mitogen-activated protein kinases and various C/EBP homologues. Furthermore, this modulation of ischemia injury factors in the SAM model group treated with magnolol seems to result from a suppression of reactive oxygen species production and the upregulation of p-Akt and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). These findings confirm the anti-oxidative properties of magnolol, including the inhibition of ischemic injury to neurons; this protective effect seems to involve changes in the in vivo activity of Akt, GSK3β and NF-κB.

Keywords: Akt; Inducible NO synthase; Magnolol; NF-κB; Stroke animal model; p38 mitogen-activated protein kinases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biphenyl Compounds / pharmacology*
  • Blotting, Western
  • Brain / pathology
  • Brain Ischemia / drug therapy*
  • Brain Ischemia / pathology
  • Cell Death
  • Endoplasmic Reticulum Stress / drug effects
  • Immunohistochemistry
  • Indicators and Reagents
  • Ischemic Attack, Transient / drug therapy
  • Ischemic Attack, Transient / pathology
  • Lignans / pharmacology*
  • Male
  • NF-kappa B / metabolism
  • Neurons / drug effects*
  • Neurons / pathology
  • Neuroprotective Agents*
  • Nitric Oxide Synthase Type II / metabolism
  • Oncogene Protein v-akt / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Reactive Oxygen Species / metabolism
  • Stroke / drug therapy
  • Stroke / pathology
  • Transcription Factor CHOP / antagonists & inhibitors*
  • Transcription Factor CHOP / metabolism
  • Tyrosine / analogs & derivatives*
  • Tyrosine / antagonists & inhibitors
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors*
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Biphenyl Compounds
  • Ddit3 protein, rat
  • Indicators and Reagents
  • Lignans
  • NF-kappa B
  • Neuroprotective Agents
  • Reactive Oxygen Species
  • magnolol
  • Transcription Factor CHOP
  • 3-nitrotyrosine
  • Tyrosine
  • Nitric Oxide Synthase Type II
  • Oncogene Protein v-akt
  • p38 Mitogen-Activated Protein Kinases