Fasudil and ozagrel in combination show neuroprotective effects on cerebral infarction after murine middle cerebral artery occlusion

Rho kinase (ROCK), one of the serine/threonine kinases, is involved in pathologic conditions, and its activation causes neuronal cell death. Fasudil, a selective ROCK inhibitor, has been reported to cause increased cerebral blood flow (CBF) in the ischemic brain and protect against neuronal cell death by inhibiting ROCK. Ozagrel, a thromboxane A(2) synthase inhibitor, inhibits platelet aggregation and causes vasodilatation, thereby increasing CBF in cerebral thrombosis. The present study evaluates the combination therapy of fasudil and ozagrel on focal brain ischemia induced by middle cerebral artery occlusion (MCAO) in mice. Each monotherapy of fasudil at 10 mg/kg i.p. and ozagrel at 30 mg/kg i.p. significantly reduced cerebral infarction. The combination therapy of fasudil (3 mg/kg i.p.) and ozagrel (10 mg/kg i.p.), which are noneffective doses, resulted in reduction of cerebral infarction, and the protective effect was observed up to 5 min, but not 3 h, after reperfusion. Regional CBF after MCAO and phosphorylation of endothelial nitric-oxide synthase (NOS) significantly increased in response to the combination therapy, whereas these effects were not observed with monotherapy of either drug. The protective effect of combination treatment was antagonized by the treatment of a NOS inhibitor, nitro-l-arginine methyl ester hydrochloride. These findings indicate that the combination treatment of fasudil and ozagrel exhibits additive effects for neuroprotection after MCAO. These findings indicate that the combination treatment of fasudil and ozagrel may be useful as a potential therapeutic strategy for the treatment of stroke.