Icariin,the major active component of Chinese medicinal herb epimedium brevicomum maxim,is used widely in traditional Chinese medicine for the treatment of neurological diseases.However,the effects of icariin on myelin inhibitory factors are as yet unclear.In the present study,administration of icariin at 20 mg/kg showed a marked reduction in neurological deficit of middle cerebral artery occlusion rats.Icariin exhibited better inhibitory effects on myelin inhibitory factors: Nogo-A,myelin-associated glycoprotein and oligodendrocyte myelin glycoprotein in ischemia regions of middle cerebral artery occlusion rats compared with monosialotetrahexosylganglioside.These results indicate that icariin exhibits potent inhibitory effects on expression of myelin inhibitors after middle cerebral artery occlusion-induced focal cerebral ischemia in vivo.This effect may be mediated,at least in part,by the inhibition of both Nogo-A,myelin-associated glycoprotein and oligodendrocyte myelin glycoprotein activation,followed by the enhancement of axonal sprouting and regeneration,resulting in neurological functional recovery.