Protective effects of organic acid component from Taraxacum mongolicum Hand.-Mazz. against LPS-induced inflammation: Regulating the TLR4/IKK/NF-κB signal pathway

J Ethnopharmacol. 2016 Dec 24;194:395-402. doi: 10.1016/j.jep.2016.08.044. Epub 2016 Aug 24.

Abstract

Ethnopharmacological relevance: TMHM is a type of Chinese medicine commonly used in medical practice and has multiple functions, including clearing heat, detoxification, reducing swelling, and tumor therapy. Previous research has demonstrated that the OAC of TMHM (TMHM-OAC) displays advantageous therapeutic action against respiratory inflammation. However, the effect of TMHM-OAC on inflammatory injury and its anti-inflammatory role requires further clarification.

Materials and methods: An in vitro inflammation damage model was employed using NHBE cells and 100ng/ml of (LPS). HPLC-DAD was conducted to analyze the components of TMHM-OAC. An ELISA was conducted to determine IL-1β, IL-6, TNF-α, and NO expression. An MTT assay was conducted to determine the cytotoxicity of TMHM-OAC. The levels of IL-1β, IL-6, TNF-α, caspase-3, caspase-8, iNOS, TLR4p-nuclear factor kappa-B kinase (p-IκκB), and p-NF-κB p65 in cellular protein, as well as the mRNA levels, were determined using WB, IF testing, and Q-PCR.

Results: TMHM-OAC significantly reduced LPS-induced NHBE cell inflammation, which was reflected in the reduced expression of relevant cytokines such as TNF-α, IL-1β, IL-6 and NO, caspase-3, and caspase-8. In addition, this component suppressed TLR4, p-IKKβ, and p-NF-κB p65 levels in both mRNA and cellular protein.

Conclusion: TMHM-OAC can reduce LPS-induced inflammation in NHBE cells and this function could be linked to the regulation of the TLR4/IKK/NF-kB pathway.

Keywords: Anti-inflammation; Caffeic Acid (PubChem CID: 1549111); Chlorogenic Acid (PubChem CID:1794427); Cichoric Acid(PubChem CID: 5281764); TLR4/IKK/NF-kB signaling pathway; TMHM-OAC.

MeSH terms

  • Apoptosis / drug effects
  • Cells, Cultured
  • Humans
  • I-kappa B Kinase / metabolism*
  • Inflammation / chemically induced
  • Inflammation / metabolism
  • Inflammation / prevention & control*
  • Lipopolysaccharides / toxicity*
  • NF-kappa B / metabolism*
  • Plant Extracts / pharmacology*
  • Signal Transduction / drug effects*
  • Taraxacum / chemistry*
  • Toll-Like Receptor 4 / metabolism*

Substances

  • Lipopolysaccharides
  • NF-kappa B
  • Plant Extracts
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • I-kappa B Kinase