ABSTRACT
OBJECTIVE：To study the improvement effects of icariside Ⅱ（ICS Ⅱ）on neurological function of focal cerebral ischemia model rats by regulating miR- 141-3p/Notch/nuclear factor erythroid- 2-related factor 2（Nrf2）axis（miR-141-3p/Notch/ Nrf2）. METHODS ：The rats were divided into sham operation group ，model group ，nimodipine group （20 mg/kg）and ICS Ⅱ low-dose，medium-dose and high-dose groups （4，8，16 mg/kg），with 20 rats in each group. Twenty-four hours after establishing focal cerebral ischemia model ，model rats were given re levant medicine or normal saline intragastrically ，twice a day ，for consecutive 3 d. The neurological deficit of rats in each group was scored ；the volume of cerebral infarction was measured by 2，3， 5-triphenyltetrazolium chloride （TTC）staining；water content of cerebral tissue and the permeability of blood-brain barrier were measured；HE staining was performed to observe the pathological change of cerebral tissue of rats ；the expression of miR- 141-3p in cerebral tissue of rats was measured by qRT-PCR ；the protein expression of Notch and Nrf 2 in cerebral tissue of rats were measured by Western blotting assay. RESULTS ：Compared with sham operation group ，the neurological deficit score ，expression of Notch-1 and Nrf 2 in model group were significantly lowered （P＜0.05）；infarction volume ，brain water content ，the permeability of blood-brain barrier and the expression of miR- 141-3p in cerebral tissue were increased significantly （P＜0.05）；the distribution of cortical cells was disordered ，and inflammatory infiltration and necrosis were observed in a large number of nerve cells. Compared with model group ，the neurological deficit score ，the protein expression of Notch- 1 and Nrf 2 in cerebral tissue were significantly increased in ICS Ⅱgroups（P＜0.05）；infarction volume ，brain water content ，the permeability of blood-brain barrier and the expression of miR- 141-3p in cerebral tissue were decreased significantly （P＜0.05）；the arrangement of cortical cells was regular，and the inflammatory infiltration and necrosis of nerve cells were decreased significantly. CONCLUSIONS ：ICS Ⅱ can promote the recovery of neurological function in focal cerebral ischemic model rats ，which may be related to down-regulation of miR-141-3p and activation of Notch/Nrf 2 axis.