The Study Of Terminalia Chebula Active Ingredients Promoting Angiogenesis After Cerebral Ischemia Injury By Nrf2/HO-1

Objective: To investigate the angiogenesis effect of extract from T.chebula seeds on cerebral ischemia reperfusion rats and to explore whether the major medicinal substance of T.chebula,corellatin,can reduce oxidative stress and promote angiogenesis by activating Nrf2 signal pathway to exert the protective effect of cerebral ischemia reperfusion injury.Methods: 1.Rat model of middle cerebral artery occlusion was prepared by suture method.The experiment was divided into sham group,I/R group,TCE group(20,50,100 mg/kg).sham group and I/R group were given normal saline,after continuous administration for 7 days,the rats in each group were evaluated by Garcia method with neurobehavioral evaluation,The area of cerebral infarction was determined by TTC staining,the morphological changes of the infarct cells was determined by HE staining,microvascular density in cerebral infarction was determined by Weidner method,EPCs levels were determined by flow cytometry,and VEGF,VEGFR-2 and NO levels were determined by enzyme-linked immunosorbent assay.2.The experiment was divided into Sham group,IR group,IR-CL group,siNrf2-CL group and siCon-CL group.siRNA was injected ipsilaterally into the left lateralcerebral ventricleat 24 h interval for 3 days prior to ischemia or sham surgery.Neurobehavioral evaluation was performed after 7 days of continuous administration,The area of cerebral infarction was determined by TTC staining,Morphological changes of cells were observed by HE and TUNEL staining.To evaluate the antioxidant indexes such as SOD,GPx,MDA,simulate the process of ischemia reperfusion in vivo with OGD in cerebral cortex neurons of rats,and to explore the protective effect of Nrf2/ HO-1 pathway on ischemic brain injury by knockdown siRNA.Results: TCE could significantly ameliorate infarct volume,improve neural function,increase brain microvessel density and endothelial progenitor cells in cerebral infraction rats,elevating the vascular endothelial growth factor and VEGF receotor-2 expression and decreace NO levels.The volume of cerebral infarction and apoptotic cells in rats were significantly reduced after the treatment with corilagin,meanwhile,MDA level significantly decreased in MCAO rats after treatment with CL,the activity of SOD and GSH was recovered,the expression of VEGF and VEGFR2 were increased.However,injection of short interfering RNA targeting Nrf2 into the intrathecal for 3 consecutive days at a 24-hour interval 3 days before ischemia reduced the beneficial effect of lilacing.In primary cultured neurons,lilacin has a dose-dependent protective effect against hypoxia and glucose-deprivation induced injury,but the down-regulation of Nrf2 weakens the protective effect of lilacin.However,injection of Nrf2 siRNA with 24 h interval for 3 days before ischemia reduced the beneficial effect of CL.In primary cultured neurons,CL has a dose-dependent protective effect against OGD induced injury,but this effect was abolished by Nrf2-siRNA.Conclusion: The extract of terminalia and corilargin could reduce oxidative stress and promote angiogenesis,to playing a protective role in cerebral ischemia/reperfusion injury,and this effect was achieved by Nrf2/ HO-1 signaling pathway.