Neuroprotective effect of bicyclol in rat ischemic stroke: down-regulates TLR4, TLR9, TRAF6, NF-κB, MMP-9 and up-regulates claudin-5 expression

Brain Res. 2013 Aug 28:1528:80-8. doi: 10.1016/j.brainres.2013.06.032. Epub 2013 Jul 10.

Abstract

Background: Inflammatory damage aggravates the cerebral ischemic pathological process and may pave a new way for treatment. Bicyclol has been proved to elicit a series of biologic effects through its anti-inflammatory property in treating hepatitis and hepatic ischemic/reperfusion injury. Whether this protective effect applies to cerebral ischemic injury, we therefore investigated the potential neuroprotective role of bicyclol and the underlying mechanisms.

Methods: Male Sprague-Dawley rats were randomly assigned to five groups: permanent middle cerebral artery occlusion (pMCAO), Vehicle (pMCAO+0.5% sodium carboxymethylcellulose), By-L (Vehicle+bicyclol 50 mg/kg), By-H (Vehicle+bicyclol 100 mg/kg) and Sham operated group. Bicyclol was administered intragastrically once a day for 3 days, after 1h of bicyclol pretreatment on the third day; rat brain ischemia was induced by pMCAO. Neurological deficit, infarct volume, and brain edema were measured at 24 h after stroke. Immunohistochemistry, Western blot and real-time quantitative PCR were used to detect the expression of TLR4, TLR9, TRAF6, NF-κB and MMP-9, claudin-5.

Results: Compared with pMCAO group, bicyclol significantly ameliorated neurological deficit, decreased infarct volume and edema, and down-regulated the expression of TLR4, TLR9, TRAF6, NF-κB and MMP-9 (P<0.05). Meanwhile, the expression of claudin-5 was increased (P<0.05).

Conclusions: Bicyclol has neuroprotective effect on cerebral ischemia, and this protection may be through down-regulating TLR4, TLR9, TRAF6, NF-κB, MMP-9 and up-regulating claudin-5 expression.

Keywords: Bicyclol; Ischemic stroke; NF-κB; Protection; TLR4; TRAF6.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biphenyl Compounds / pharmacology*
  • Brain / drug effects*
  • Brain / pathology
  • Claudin-5 / metabolism
  • Down-Regulation
  • Infarction, Middle Cerebral Artery / metabolism*
  • Infarction, Middle Cerebral Artery / pathology
  • Male
  • Matrix Metalloproteinase 9 / metabolism
  • NF-kappa B / metabolism
  • Neuroprotective Agents / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • TNF Receptor-Associated Factor 6 / metabolism
  • Toll-Like Receptor 4 / metabolism
  • Toll-Like Receptor 9 / metabolism
  • Up-Regulation

Substances

  • Biphenyl Compounds
  • Claudin-5
  • Cldn5 protein, rat
  • NF-kappa B
  • Neuroprotective Agents
  • TNF Receptor-Associated Factor 6
  • Tlr4 protein, rat
  • Tlr9 protein, rat
  • Toll-Like Receptor 4
  • Toll-Like Receptor 9
  • bicyclol
  • Matrix Metalloproteinase 9