Purification, Characterization and Neuroprotective Effects of a Polysaccharide From Gynostemma Pentaphyllum

Carbohydr Polym. 2015 May 20;122:93-100. doi: 10.1016/j.carbpol.2014.12.032. Epub 2014 Dec 31.

Abstract

In the present study, we investigated the neuroprotective effects of GPP1, a purified polysaccharide from Gynostemma pentaphyllum, on Aβ (25-35)-induced neuronal toxicity and explore its potential mechanisms in PC12 cells. The results showed pretreatment with GPP1 prior to Aβ (25-35) exposure significantly protected PC12 cells from Aβ (25-35)-induced cell death, lactate dehydrogenase (LDH) release, DNA damage, intracellular free calcium concentration ([Ca(2+)]i) influx, mitochondrial dysfunction and mitochondrial cytochrome c (Cyt-C) release. In addition, pretreatment with GPP1 also protected PC12 cells against Aβ (25-35)-induced the accumulation of reactive oxygen species (ROS) and lipid peroxidation product MDA, the reduction in glutathione (GSH) level and superoxide dismutase (SOD) activity, the increased Bax/Bcl-2 protein expression ratio and caspase-3 activation. Our findings suggest that GPP1 exerts a neuroprotective effect against Aβ (25-35)-induced neurotoxicity in PC12 cells, at least in part, via inhibiting oxidative stress and suppressing the mitochondrial apoptotic pathway.

Keywords: Antioxidant; Apoptosis; Gynostemma pentaphyllum; Isolation; Polysaccahride.

MeSH terms

  • Amyloid beta-Peptides / toxicity
  • Animals
  • Apoptosis / drug effects
  • Calcium / metabolism
  • Cytochromes c / metabolism
  • DNA Damage
  • Gene Expression Regulation / drug effects
  • Gynostemma / chemistry*
  • Mitochondria / drug effects
  • Neuroprotective Agents / chemistry
  • Neuroprotective Agents / isolation & purification*
  • Neuroprotective Agents / pharmacology*
  • Oxidative Stress / drug effects
  • PC12 Cells
  • Peptide Fragments / toxicity
  • Polysaccharides / chemistry
  • Polysaccharides / isolation & purification*
  • Polysaccharides / pharmacology*
  • Rats
  • Signal Transduction / drug effects

Substances

  • Amyloid beta-Peptides
  • Neuroprotective Agents
  • Peptide Fragments
  • Polysaccharides
  • amyloid beta-protein (25-35)
  • Cytochromes c
  • Calcium