Neuroprotection of Oral Edaravone on Middle Cerebral Artery Occlusion in Rats

Edaravone has been widely used in the treatment of acute ischemic stroke. However, there has been no oral preparation of edaravone in the clinic. In this study, we assessed the effect and possible mechanisms of oral edaravone on the middle cerebral artery occlusion (MCAO) model in rats. Highly bioavailable form of novel edaravone formulation developed using self-nanomicellizing solid dispersion strategy which showed up to 16.1-fold improved oral bioavailability was considered oral edaravone. The male rats (n = 84) were randomly divided into sham; model; oral edaravone in low dose (10 mg/kg), medium dose (20 mg/kg), and high dose (30 mg/kg); and edaravone by intraperitoneal administration group (IP group, 10 mg/kg). Rats were treated with different drugs 5 h after the operation, twice a day for 7 days. The behavioral data were dose-dependently improved by oral edaravone and sensorimotor functions of the high dose group were similar to those of the edaravone by IP route group. Furthermore, oral edaravone significantly reduced cerebral infarction area and downregulated the levels of caspase-3, GFAP, Iba1, 3-NT, and 4-HNE, whereas upregulated those of Vamp-2 and Map-2 in a dose-dependent manner. Especially effect of the high dose on these molecules was equal to that of edaravone by IP administration. Taken together, our data suggest that the improvement of sensorimotor deficits by oral edaravone in high doses after ischemia is similar to that in edaravone by IP administration. Neuroprotection of oral edaravone is at least partial by minimizing oxidative stress, the overactivation of glial cells, and the levels of the apoptosis-associated proteins, and alleviating synaptic damage in a dose-dependent manner.