TOP 1 and 2, polysaccharides from Taraxacum officinale, inhibit NFκB-mediated inflammation and accelerate Nrf2-induced antioxidative potential through the modulation of PI3K-Akt signaling pathway in RAW 264.7 cells

Food Chem Toxicol. 2014 Apr;66:56-64. doi: 10.1016/j.fct.2014.01.019. Epub 2014 Jan 18.

Abstract

Anti-inflammatory and anti-oxidative activities of polysaccharides from Taraxacum officinale (TOP 1 and 2) were analyzed in RAW 264.7 cells. First, lipopolysaccharide (LPS) was applied to identify anti-inflammatory activity of TOPs, which reduced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α. TOPs treatment inhibited phosphorylation of inflammatory transcription factor, nuclear factor (NF)κB, and its upstream signaling molecule, PI3K/Akt. Second, cytoprotective potential of TOPs against oxidative stress was investigated via heme oxygenase (HO)-1 induction. HO-1, one of phase II enzymes shows antioxidative activity, was potently induced by TOPs treatment, which was in accordance with the nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2). In addition, TOPs treatment phosphorylated PI3K/Akt with slight activation of c-Jun NH2-terminal kinase (JNK). TOPs-mediated HO-1 induction protected macrophage cells from oxidative stress-induced cell death, which was confirmed by SnPP and CoPP (HO-1 inhibitor and inducer, respectively). Consequently, TOPs potently inhibited NFκB-mediated inflammation and accelerated Nrf2-mediated antioxidative potential through the modulation of PI3K/Akt pathway, which would contribute to their promising strategy for novel anti-inflammatory and anti-oxidative agents.

Keywords: Anti-inflammatory; Antioxidative; NFκB; Nrf2; PI3KAkt; Taraxacum officinale polysaccharide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / metabolism*
  • Cell Line
  • Heme Oxygenase-1 / metabolism
  • Inflammation / prevention & control*
  • Macrophages / drug effects
  • Macrophages / enzymology
  • Macrophages / metabolism
  • Mice
  • NF-E2-Related Factor 2 / metabolism*
  • NF-kappa B / antagonists & inhibitors*
  • NF-kappa B / physiology
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Polysaccharides / pharmacology*
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction / drug effects
  • Taraxacum / chemistry*

Substances

  • Antioxidants
  • NF-E2-Related Factor 2
  • NF-kappa B
  • Nfe2l2 protein, mouse
  • Polysaccharides
  • Heme Oxygenase-1
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt