Bletilla striata polysaccharide inhibits angiotensin II-induced ROS and inflammation via NOX4 and TLR2 pathways

Int J Biol Macromol. 2016 Aug:89:376-88. doi: 10.1016/j.ijbiomac.2016.05.002. Epub 2016 May 3.

Abstract

In the current study, we analyzed the functions and mechanisms of Bletilla striata polysaccharide b (BSPb) against Angiotensin II (Ang II)-induced oxidative stress and inflammation in human mesangial cells (HMCs). It was found that BSPb could inhibit generation of Ang II-induced reactive oxygen species (ROS) and activation of proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) in a dose-dependent manner. Further studies revealed that BSPb effectively blocked upregulation of NADPH oxidase 4 (NOX4). Moreover, knockdown of NOX4 significantly impaired the anti-oxidative function of BSPb. In addition, BSPb decreased overexpression of Toll-like receptor 2 (TLR2) induced by Ang II. Blocking TLR2 expression impaired the anti-inflammatory effects of BSPb. In conclusion, BSPb was found to possess anti-oxidative stress and anti-inflammatory functions against Ang II-induced ROS generation and proinflammatory cytokines activation. The NOX4 and TLR2 pathways played important roles in the biological effects mediated by BSPb.

Keywords: Bletilla striata polysaccharide; Inflammation; Reactive oxygen species.

MeSH terms

  • Angiotensin II / drug effects
  • Angiotensin II / metabolism
  • Cell Line
  • Gene Expression Regulation / drug effects
  • Humans
  • Inflammation / drug therapy*
  • Inflammation / genetics
  • Inflammation / pathology
  • Mesangial Cells / drug effects
  • Mesangial Cells / metabolism
  • NADPH Oxidase 4
  • NADPH Oxidases / biosynthesis
  • NADPH Oxidases / genetics*
  • Orchidaceae / chemistry
  • Oxidative Stress / drug effects
  • Plant Extracts / administration & dosage*
  • Plant Extracts / chemistry
  • Polysaccharides / administration & dosage*
  • Polysaccharides / chemistry
  • Reactive Oxygen Species / metabolism
  • Signal Transduction / drug effects
  • Toll-Like Receptor 2 / biosynthesis
  • Toll-Like Receptor 2 / genetics*

Substances

  • Plant Extracts
  • Polysaccharides
  • Reactive Oxygen Species
  • TLR2 protein, human
  • Toll-Like Receptor 2
  • Angiotensin II
  • NADPH Oxidase 4
  • NADPH Oxidases
  • NOX4 protein, human