Superoxide scavenging activity of pirfenidone-iron complex

Biochem Biophys Res Commun. 2008 Jul 18;372(1):19-23. doi: 10.1016/j.bbrc.2008.04.093. Epub 2008 May 9.


Pirfenidone (PFD) is focused on a new anti-fibrotic drug, which can minimize lung fibrosis etc. We evaluated the superoxide (O2*-) scavenging activities of PFD and the PFD-iron complex by electron spin resonance (ESR) spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. Firstly, we confirmed that the PFD-iron complex was formed by mixing iron chloride with threefold molar PFD, and the complex was stable in distilled water and ethanol. Secondary, the PFD-iron complex reduced the amount of O2*- produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. Thirdly, it also reduced the amount of O2*- released from phorbor ester-stimulated human neutrophils. PFD alone showed few such effects. These results suggest the possibility that the O2*- scavenging effect of the PFD-iron complex contributes to the anti-fibrotic action of PFD used for treating idiopathic pulmonary fibrosis.

MeSH terms

  • Cell Line
  • Free Radical Scavengers / chemical synthesis
  • Free Radical Scavengers / pharmacology*
  • Free Radical Scavengers / therapeutic use
  • Humans
  • Iron
  • Neutrophils / drug effects
  • Neutrophils / metabolism
  • Pulmonary Fibrosis / drug therapy
  • Pyridones / chemistry
  • Pyridones / pharmacology*
  • Pyridones / therapeutic use
  • Superoxides / chemistry
  • Superoxides / metabolism*


  • Free Radical Scavengers
  • Pyridones
  • Superoxides
  • pirfenidone
  • Iron