4-methoxycinnamyl p-coumarate isolated from Etlingera pavieana rhizomes inhibits inflammatory response via suppression of NF-κB, Akt and AP-1 signaling in LPS-stimulated RAW 264.7 macrophages

Phytomedicine. 2019 Feb 15:54:89-97. doi: 10.1016/j.phymed.2018.09.193. Epub 2018 Sep 18.

Abstract

Background: 4-methoxycinnamyl p-coumarate (MCC) was isolated from rhizomes of Etlingera pavieana by bioactivity-guided isolation, however, the molecular mechanism underlying its anti-inflammatory activity remains inadequately understood.

Purpose: In this study, we elucidated the suppressive effect of MCC on LPS-induced expression of inflammatory mediators and the molecular mechanisms responsible for anti-inflammatory activities in RAW 264.7 macrophages.

Methods: Cell viability of MCC-treated RAW 264.7 macrophage was measured by MTT assay. Anti-inflammatory activity was evaluated by measurement of NO, PGE2, and cytokine production in LPS-stimulated cells. qRT-PCR and Western blotting analysis were used to investigate mRNA and protein levels of inflammatory responsive genes. NF-κB activation and transactivation activity were determined by immunofluorescence and reporter gene assay, respectively.

Results: MCC considerably suppressed both the production of NO, PGE2, IL-1β as well as TNF-α and their expression. MCC inactivated NF-κB by reducing phosphorylation of IκBα and inhibiting NF-κB p65 nuclear translocation. Also, MCC significantly inhibited NF-κB transactivation activity. However, the inhibitory effect of MCC was independent of the MAPK signaling pathway. Furthermore, MCC significantly decreased phosphorylation of Akt and c-Jun, a main component of AP-1.

Conclusion: These findings suggest that the anti-inflammatory effect of MCC could be mediated by the inhibition of LPS-induced expression of inflammatory mediators by down-regulation of the NF-κB, Akt and AP-1 signaling pathways in murine macrophages.

Keywords: 4-methoxycinnamyl p-coumarate; AP-1, activator protein-1; Abbreviations: MCC, 4-methoxycinnamyl p-coumarate; Akt, Protein Kinase B; Anti-inflammatory Activity; COX-2, cyclooxygenase-2; Cytokines; ERK, Extracellular signal-regulated kinase; IL-1β, interleukin-1β; JNK, c-Jun N-terminal Kinase; LPS, Lipopolysaccharide; MAPK, mitogen-activated protein kinase; Macrophage; NF-κB, Nuclear factor-kappa B; NO, nitric oxide; Nitric Oxide; PGE(2), prostaglandins E(2); Prostaglandins E(2); TNF-α, tumor necrosis factor-α; iNOS, inducible nitric oxide synthase.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / isolation & purification
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Coumaric Acids / isolation & purification
  • Coumaric Acids / pharmacology*
  • Cytokines / metabolism
  • Dinoprostone / metabolism
  • Drug Evaluation, Preclinical / methods
  • Inflammation / drug therapy*
  • Inflammation / metabolism
  • Lipopolysaccharides / pharmacology
  • Mice
  • NF-kappa B / metabolism
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism
  • RAW 264.7 Cells
  • Rhizome / chemistry
  • Signal Transduction / drug effects
  • Transcription Factor AP-1 / metabolism
  • Zingiberaceae / chemistry*

Substances

  • 4-methoxycinnamyl p-coumarate
  • Anti-Inflammatory Agents, Non-Steroidal
  • Coumaric Acids
  • Cytokines
  • Lipopolysaccharides
  • NF-kappa B
  • Transcription Factor AP-1
  • Proto-Oncogene Proteins c-akt
  • Dinoprostone