Suppression of Baeckea frutescens L. and its components on MyD88-dependent NF-κB pathway in MALP-2-stimulated RAW264.7 cells

J Ethnopharmacol. 2017 Jul 31:207:92-99. doi: 10.1016/j.jep.2017.05.034. Epub 2017 May 31.

Abstract

Ethnopharmacological relevance: Baeckea frutescens L. is commonly used as a folk medicinal material. There are nineteen components in its volatile oil, including Pcymol which has effects of eliminating phlegm, relieving asthma and antiviral. This study was aimed to investigate the anti-infectious inflammatory activities of Baeckea frutescens L. and its conponents and analyzing the mechanisms.

Materials and methods: The anti-infectious inflammation of Baeckea frutescens L. were studied by using macrophage activating lipopeptide-2 (MALP-2)-stimulated RAW264.7 cell model in vitro. Secretion of nitric oxide (NO), expression of inducible NO synthase (iNOS) and cytokines were detected as classic inflammatory index. Expression of Myeloid differentiation factor 88 (MyD88), degradation of inhibitory κBα (IκBα) and nuclear translocation of NF-κB p65 were further investigated.

Results: The results suggested that Baeckea frutescens L. has effect on suppression of MALP-2-mediated inflammation in RAW264.7 cells. The secretion of NO and the expression of iNOS could be inhibited. The secretion of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were also declined. Baeckea frutescens L. significantly decreased the expression of MyD88, therefore, inhibited the degradation of IκBα, reduced the level of nuclear translocation of p65.

Conclusion: The results of this study indicated that Baeckea frutescens L. and its components could inhibit the anti-infectious inflammatory events and iNOS expression in MALP-2 stimulated RAW264.7 cells. Among them, BF-2 might play a role through the inhibition of the MyD88 and NF-κB pathway. Our study might provide a new strategy to design and develop this kind of drug towards mycoplasma-infected inflammation.

Keywords: Baeckea frutescens L.; Infectious inflammation; MALP-2; MyD88; NF-κB.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / isolation & purification
  • Anti-Inflammatory Agents / pharmacology*
  • Inflammation / drug therapy*
  • Inflammation / pathology
  • Interleukin-6 / metabolism
  • Lipopeptides / administration & dosage
  • Macrophages / drug effects
  • Macrophages / pathology
  • Mice
  • Mycoplasma Infections / drug therapy
  • Mycoplasma Infections / pathology
  • Myeloid Differentiation Factor 88 / metabolism
  • Myrtaceae / chemistry*
  • NF-kappa B / metabolism
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type II
  • Plant Extracts / pharmacology*
  • RAW 264.7 Cells
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Anti-Inflammatory Agents
  • Interleukin-6
  • Lipopeptides
  • Myeloid Differentiation Factor 88
  • NF-kappa B
  • Plant Extracts
  • Tumor Necrosis Factor-alpha
  • Nitric Oxide
  • macrophage stimulatory lipopeptide 2
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse