化香树果序多糖对大鼠脑缺血再灌注损伤的保护及其作用机制研究

Protective effects of polysaccharides from Platycarya strobilacea Sieb.et Zucc on cerebral ischemia-reperfusion injury in rat

目的 探讨化香树果序多糖对大鼠脑缺血再灌注损伤的保护作用.方法 将40只Wistar大鼠随机分为4组,分别为：模型组、假手术组以及化香树果序多糖高、低两个剂量组,其中高剂量给予400mg/kg的化香树果序多糖,低剂量组给予100mg/kg的化香树果序多糖,连续给药7d,在末次给药1h后,对颈总动脉近端进行结扎处理以复制脑缺血再灌注损伤模型.根据Zea longa＆#39;s分数的方法评价神经功能评分,同时,利用2,3,5-氯化三苯基四氮唑（TTC）染色法对各组大鼠脑梗死百分比进行测定,并测定脑组织中超氧化物歧化酶（SOD）的活性以及丙二醛（MDA）、白细胞介素-10（interleukin-10,IL-10）、白细胞介素-1β（interleukin-1β,IL-1β）和肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）含量.采用TUNEL染色的方法考察神经细胞的凋亡情况.采用western blot的方法对大鼠脑组织中核因子红细胞2相关因子2（Nuclear factor erythroid 2-related factor 2,Nrf2）和血红素氧合酶-1（HO-1）的表达量进行测定.结果 与模型组比较,化香树果序多糖能够大幅降低大鼠脑组织中MDA、IL-1β和TNF-α的含量,提高脑组织中SOD的活性以及IL-10的含量,并有效降低脑梗死百分比、减少脑组织缺血区域细胞的凋亡.同时化香树果序多糖能够显著提高Nrf2和HO-1在脑缺血大鼠脑组织中的表达量.结论 化香树果序多糖对脑缺血再灌注损伤大鼠具有保护作用,其保护机制可能与Nrf2/HO-1介导的信号通路有关.

Objective To investigate protective effects of polysaccharides from Platycarya strobilacea Sieb.et Zucc on cerebral ischemia-reperfusion injury in rats.MethodsForty Wistar rats were randomly divided into four groups：sham group,model group,Rehmannia glutinosa polysaecharide low,and high dose groups.Each group was given oral administration for 7 days.After 1 h of last administration, the CIRI （cerebral ischemia-reperfusion injury） group was produced inserting 5-0 line into the internal carotid artery.Neurological functional score was evaluated according to the method of Zea longa＆#39;s score, meanwhile,infarct size was detected by TTC staining.Levels of superoxide dismutase （SOD） activity,malondialdehyde （MDA）, IL-10, IL-1β and TNF-α contents in cerebral tissues were measured.TUNEL staining was used to assess the number of TUNEL-positive cells of the ischemic cortex.Western blot was used to analyze the expressions of Nrf2 and HO-1 in cerebral tissues.ResultsCompared to model group, Platycarya strobilacea a polysaccharides could significantly improve neurogical functions,greatly decrease the contents of MDA, IL-10 and IL-1β in cerebral tissues,improve SOD activity and IL-10 content in cerebral tissues,and effectively reduce cerebral infarct range.Meanwhile Platycarya strobilacea polysaccharides could enhance the expressions of Nrf2 and HO-1 in cerebral tissues.ConclusionPlatycarya strobilacea polysaccharides have beneficial effects on rats with cerebral ischemia-reperfusion injury, which may be mediated at least in part by the Nrf2/HO-1 pathway.