Role of lipid-derived free radical in bleomycin-induced lung injury in mice: availability for ESR spin trap method with organic phase extraction.

Bleomycin is well known as causative molecule for acute lung injury and interstitial pneumonia. The free radical production from bleomycin is thought to play an important role in the pathogenesis of acute lung injury and interstitial pneumonia. However, there was no direct evidence of free radical production in this model.

Superoxide scavenging activity of pirfenidone-iron complex.

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.

Applicability of new spin trap agent, 2-diphenylphosphinoyl-2-methyl-3,4-dihydro-2H-pyrrole N-oxide, in biological system.

Electron spin resonance using spin-trapping is a useful technique for detecting direct reactive oxygen species, such as superoxide (O2.-). However, the widely used spin trap 2,2-dimethyl-3,4-dihydro-2H-pyrrole N-oxide (DMPO) has several fundamental limitations in terms of half-life and stability.