4'-O-β-D-Glucosyl-5-O-Methylvisamminol, A Natural Histone H3 Phosphorylation Epigenetic Suppressor, Exerts a Neuroprotective Effect Through PI3K/Akt Signaling Pathway on Focal Cerebral Ischemia in Rats

World Neurosurg. 2016 May:89:474-88. doi: 10.1016/j.wneu.2016.01.061. Epub 2016 Feb 8.

Abstract

Background: A bursting inflammation has been observed that compromises neurologic function in patients who experience stroke. We sought to examine the neuroprotective efficacy of 4'-O-β-D-glucosyl-5-O-methylvisamminol (OGOMV), a novel histone H3 phosphorylation epigenetic suppressor) in a transient middle cerebral artery occlusion (tMCAO).

Methods: A rodent tMCAO model was used. Administration with 400 μg/kg/day OGOMV was initiated 12 hours before (prevention) and 1 hour after animals were subjected to tMCAO (reversal). The cerebral cortex was harvested to examine protein kinase B (PI3D/Akt), 5-bromo-2'-deoxyuridine (Western blot), and caspases (reverse-transcription polymerase chain reaction). In addition, cerebrospinal fluid samples were collected to examine interleukin 1-β, interleukin-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α (reverse-transcription polymerase chain reaction).

Results: Cortical 5-bromo-2'-deoxyuridine and phospho-PI3D/Akt were reduced in tMCAO animals, compared with the healthy controls but increased in the OGOMV treatment and prevention groups. Activated cortical caspase-3,-6, and -9a as well as increased IL-1β and TNF-α levels were observed in the tMCAO animals (P < 0.05). Both prevention and treatment with OGOMV significantly reduced cleaved caspase-3 and -9a groups, but no significant change in caspase-6 was noted. Perifosine, an Akt inhibitor, was added to reduce the bioexpression of phospho-P13D/Akt, and Bcl-2 level and increased cleaved caspase-9a level in both OGOMV prevention and treatment tMCAO groups (P > 0.05).

Conclusion: Our study suggests that OGOMV could exert a neuroprotective effect by inhibiting the P13D/Akt protein, attenuating inflammation, and cleaved caspase-3- and -9a-related apoptosis. This study also lends credence to support the notion that the prevention of OGOMV could attenuate proinflammatory cytokine mRNA and late-onset caspases in tMCAO and merits further study.

Keywords: 4′-O-β-D-glucosyl-5-O-methylvisamminol; Phosphatidylinositol-3-kinase; Protein kinase B; Transient middle cerebral artery occlusion; Tumor necrotic factor-α.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / physiology
  • Brain / drug effects
  • Brain / enzymology
  • Brain / pathology
  • Caspase 3 / metabolism
  • Caspase 9 / metabolism
  • Chromones / pharmacology*
  • Disease Models, Animal
  • Epigenesis, Genetic / drug effects
  • Glucosides / pharmacology*
  • Histones / metabolism
  • Infarction, Middle Cerebral Artery / drug therapy*
  • Infarction, Middle Cerebral Artery / enzymology
  • Infarction, Middle Cerebral Artery / pathology
  • Male
  • Neuroprotective Agents / pharmacology*
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA, Messenger / metabolism
  • Random Allocation
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects

Substances

  • 4'-O-glucosyl-5-O-methylvisamminol
  • Chromones
  • Glucosides
  • Histones
  • Neuroprotective Agents
  • RNA, Messenger
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • Casp3 protein, rat
  • Casp9 protein, rat
  • Caspase 3
  • Caspase 9