Roflumilast inhibits lipopolysaccharide-induced inflammatory mediators via suppression of nuclear factor-kappaB, p38 mitogen-activated protein kinase, and c-Jun NH2-terminal kinase activation

J Pharmacol Exp Ther. 2005 Dec;315(3):1188-95. doi: 10.1124/jpet.105.092056. Epub 2005 Aug 26.

Abstract

Roflumilast, a potent and selective phosphodiesterase 4 (PDE4) inhibitor, has been demonstrated to be an effective anti-inflammatory agent in airway inflammatory diseases. In the present study, we investigated the mechanism of anti-inflammatory effects of roflumilast in murine macrophage cell line RAW264.7 cells. Roflumilast inhibited NO, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-1beta production via suppression of their gene expressions in lipopolysaccharide (LPS)-stimulated macrophages. To elucidate the mechanism by which roflumilast inhibits the production of inflammatory mediators, we examined the effect of roflumilast on the activation of nuclear factor-kappaB (NF-kappaB) in these cells. Roflumilast inhibited the DNA binding activity of NF-kappaB by preventing inhibitor kappaBalpha phosphorylation and degradation. The phosphorylation of mitogen-activated protein (MAP) kinases, including stress-activated protein kinase/c-Jun NH2-terminal kinase (JNK) and p38 MAP kinase, was also markedly inhibited by roflumilast. Similar to the effects of roflumilast, treatment of either SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)imidazole] or SP600125 [anthra(1,9-cd)pyrazol-6(2H)-one 1,9-pyrazoloanthrone], specific inhibitors of p38 MAP kinase and JNK, respectively, suppressed NO, TNF-alpha, and IL-1beta production. Consistent with in vitro results, administration of roflumilast recovered the survival rate of LPS-treated mice, with concurrent suppression of plasma levels of nitrite/nitrate, TNF-alpha, and IL-1beta. These results suggest that the inhibitory activity of roflumilast on the production of inflammatory mediators seems to be mediated via inhibition of NF-kappaB, p38 MAP kinase, and JNK activation in macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopyridines / toxicity*
  • Animals
  • Benzamides / toxicity*
  • Cells, Cultured
  • Cyclopropanes / toxicity
  • Electrophoretic Mobility Shift Assay
  • Enzyme Activation / drug effects
  • Interleukin-1 / analysis
  • Interleukin-1 / antagonists & inhibitors
  • JNK Mitogen-Activated Protein Kinases / antagonists & inhibitors*
  • Lipopolysaccharides / pharmacology
  • Macrophages, Peritoneal / drug effects
  • Male
  • Mice
  • Mice, Inbred C57BL
  • NF-kappa B / antagonists & inhibitors*
  • Nitrites / analysis
  • Phosphodiesterase Inhibitors / toxicity*
  • Toxicity Tests
  • Tumor Necrosis Factor-alpha / analysis
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors*

Substances

  • Aminopyridines
  • Benzamides
  • Cyclopropanes
  • Interleukin-1
  • Lipopolysaccharides
  • NF-kappa B
  • Nitrites
  • Phosphodiesterase Inhibitors
  • Tumor Necrosis Factor-alpha
  • Roflumilast
  • JNK Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases