A
free radical scavenger edaravone is clinically used in Japan for
acute stroke, and several basic researches have carefully examined the mechanisms of
edaravone's protective effects. However, its actions on pro-inflammatory responses under
stroke are still understudied. In this study, we subjected adult male Sprague-Dawley rats to 90-min middle cerebral artery (MCA) occlusion followed by reperfusion.
Edaravone was treated twice via tail vein; after MCA occlusion and after reperfusion. As expected,
edaravone-treated group showed less
infarct volume and
edema formation compared with control group at 24-h after an ischemic onset. Furthermore,
edaravone reduced the levels of plasma
interleukin (IL)-1β and
matrix metalloproteinase-9 at 3-h after ischemic onset. Several molecules besides IL-1β and MMP-9 are involved in inflammatory responses under
stroke conditions. Therefore, we also examined whether
edaravone treatment could decrease a wide range of pro-inflammatory
cytokines/
chemokines by testing rat plasma samples with a rat
cytokine array. MCAO rats showed elevations in plasma levels of CINC-1,
Fractalkine, IL-1α,
IL-1ra,
IL-6,
IL-10, IP-10, MIG, MIP-1α, and MIP-3α, and all these increases were reduced by
edaravone treatment. These data suggest that
free radical scavengers may reduce systemic inflammatory responses under
acute stroke conditions, and therefore, oxidative stress can be still a viable target for
acute stroke therapy.