Dose-dependency of multiple free radical-scavenging activity of edaravone.

BACKGROUND

Edaravone is a powerful free radical scavenger that is in clinical use. However, data concerning its dose-response relationship against multiple free radicals remain sparse. The purpose of the present study was to demonstrate the dose-dependency of direct scavenging activity of edaravone against multiple free radical species.

MATERIALS AND METHODS

Free radical-scavenging activities of edaravone against six free radical species were evaluated by electron spin resonance spectroscopy using spin-trapping method.

RESULTS

Edaravone scavenged the following free radicals in dose-dependent manners with reaction rate constants (k) or 50% inhibitory concentration (IC) as indicated: hydroxyl radical (k = 5.2 × 10 M s), superoxide anion (k/k = 0.63), tert-butyl peroxyl radical (k/k = 8.8), ascorbyl free radical (IC = 0.17 ± 0.06 mM), 2,2-diphenyl-1-picrylhydrazyl (DPPH, IC = 4.7 ± 0.3 μM), and nitric oxide (k = 7.0 × 10 M s).

CONCLUSIONS

The dose-dependent scavenging activities of edaravone against multiple free radical species were clearly illustrated. It is speculated that edaravone acts as antioxidant by dose-dependently scavenging multiple free radical species along the chain reactions of oxidative stress in surgery.