An oral administration of cilostazol before focal ischemia reduces the infarct volume with delayed cerebral blood flow increase in rats.

We studied the acute brain protection provided by an antiplatelet agent, cilostazol, in rat experimental focal ischemia model. We administered 30 mg/kg of cilostazol or vehicle orally 2 hours before transient middle cerebral artery (MCA) occlusion (MCAO) by the intraluminal thread method. We measured the absolute cerebral blood flow (CBF) 2 hours after cilostazol administration, the regional CBF (rCBF) of MCA territory during MCAO, and neurologic deficits and the infarct volume at 22 hours after reperfusion. We found that cilostazol did not increase absolute CBF just before MCAO. rCBF in the MCA territory was reduced to the same degree in both groups up to 60 minutes post-MCAO. A significant increase of rCBF was observed in cilostazol-treated rats at 90 minutes and maintained until reperfusion compared with the controls (P = .031 and P = .047). The average neurologic score and the infarct volume, determined by 2,3,5-triphenyltetrazolium chloride monohydrate staining, were significantly lower in cilostazol-treated rats (P = .010). The single oral administration of cilostazol before transient ischemia in healthy adult rats induced a delayed penumbral CBF increase and resulted in a significant reduction of stroke damage.