Flavonoids of Tripodanthus acutifolius inhibit TNF-α production in LPS-activated THP-1 and B16-F10 cells

J Ethnopharmacol. 2019 Oct 5:242:112036. doi: 10.1016/j.jep.2019.112036. Epub 2019 Jun 22.

Abstract

Ethnopharmacological relevance: T. acutifolius is an endemic species from South America which has been used in traditional medicine since ancient times due to its biological properties, including its anti-inflammatory effects.

Aim of the study: The aim of the article is to investigate the inhibitory activity of T. acutifolius over TNF-α production in THP-1 and B16-F10 cells. To achieve this, phytochemical analysis has been used to determine the compounds present in the species with anti-inflammatory effects.

Materials and methods: Leaves and stems of T. acutifolius were extracted with n-heptane, dichloromethane, methanol and water. The resulting extracts were analysed in THP-1 and B16-F10 cells by measuring their inhibitory capacity over the production of TNF-α stimulated with LPS.

Results: The guided-bioassay led to the isolation of 6,2',4'-trimethoxyflavone (1), 5,3',4'-trihydroxy-6,7,8-trimethoxyflavone (2), (E)-2',4'-dihydroxy-6'-methoxy-chalcone (3) and 5,4'-dihydroxy-6,7,8-trimethoxyflavone (4) from the dichloromethanic extract. Compounds showed an inhibitory activity of TNF-⍺ production in THP-1 cells, with IC50 of 2.38 ± 0.02 μM, 12.36 ± 0.17 μM, 1.12 ± 0.01 μM and 8.09 ± 0.04 μM, respectively. In addition, the compounds showed an inhibitory activity of TNF-⍺ production in B16-F10 cells with IC50 of 1.32 ± 0.03 μM, 5.63 ± 0.09 μM, 0.60 ± 0.02 μM and 3.77 ± 0.15 μM, respectively.

Conclusions: We identified 3 flavones (6,2',4'-trimethoxyflavone, 5,3',4'-trihydroxy-6,7,8-trimethoxyflavone, 5,4'-dihydroxy-6,7,8-trimethoxyflavone) and a chalcone ((E)-2',4'-dihydroxy-6'-methoxy-chalcone) present in the leaves and stems of T. acutifolius. These compounds are an alternative for the treatment of immune-mediated inflammatory disorders, acting as negative modulators over the TNF-α production.

Keywords: Anti–inflammatory; Chalcones; Flavonoids; TNF–α; Tripodanthus.

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Flavonoids / pharmacology*
  • Humans
  • Lipopolysaccharides / pharmacology
  • Loranthaceae*
  • Melanoma, Experimental
  • Mice
  • Plant Leaves
  • Plant Stems
  • Tumor Necrosis Factor-alpha / metabolism*

Substances

  • Flavonoids
  • Lipopolysaccharides
  • Tumor Necrosis Factor-alpha