Effect of the free radical scavenger edaravone on peripheral nerve ischemia-reperfusion injury.

We investigated the effects of edaravone, a free radical scavenger, on peripheral nerve ischemia-reperfusion injury caused by ligation of vessels supplying the sciatic and tibial nerves in rats. The control group was administered a placebo, the standard-dose group was given 3 mg/kg of edaravone intraperitoneally every 24 hours, and the low-dose group was given 1 mg/kg of edaravone. At 7 days after reperfusion, neurological and electrophysiological parameters were improved in the standard-dose group as compared with the control group. After 14 days, however, these differences were no longer observed. After 21 days, persistent edema and nerve fiber degeneration were noted in the standard-dose group, but not in the control or low-dose groups. Edaravone was effective during the early reperfusion period, but chronic inhibition of reactive oxygen species may be detrimental for nerve regeneration after ischemia-reperfusion injury. Further studies are necessary to confirm the long-term influence of edaravone.