止痛努加蜜膏提取物对大鼠脑缺血损伤的保护作用及其机制研究

目的]考察止痛努加蜜膏提取物对永久性局灶性脑缺血大鼠脑缺血损伤的保护作用,初步探索其保护作用的机制。方法] SD大鼠60只,随机分为5组:假手术组、模型组、止痛努加蜜膏提取物高、低剂量组、止痛努加蜜膏提取物高剂量+LY2 94002组,采用大脑中动脉阻塞法构建永久性中动脉梗死(pMCAO)模型。参考Zea-Longa法对各组神经功能进行评分,采用2,3,5-氯化三苯基四氮唑(TTC)染色测定脑梗死百分比,采用蛋白质印迹法(Western Blot)检测脑组织中p-Akt、NF-κB、Nrf2蛋白表达情况,采用酶联免疫吸附剂测量(ELISA)法检测脑组织中TNF-α和SOD含量。结果]与假手术组相比,模型组大鼠神经功能评分,脑梗死百分比明显增加,差异有统计学意义(P<0.05)。与模型组相比,止痛努加蜜膏提取物能改善神经功能缺损评分,减小脑梗死百分比,增加脑组织中SOD含量,减少TNF-α含量,上调p-Akt和Nrf2蛋白表达,下调NF-κB蛋白表达,差异有统计学意义(P<0.05)。且加入PI3K特异性抑制剂LY294002后,提取物对脑缺血损伤的保护作用被抑制。结论]止痛努加蜜膏提取物具有神经保护作用,能够减轻永久性局灶性脑缺血损伤程度,其机制可能是通过激活PI3K/Akt信号通路,促进Akt的磷酸化,促进Nrf2蛋白表达,抑制NF-κB蛋白表达,发挥抗炎和抗氧化作用,进而产生对脑缺血损伤的保护作用。

Study on the neuroprotective effect and mechanism of Zhitong Nujia Honey Paste extraction

Objective]To investigate the protective effect of Zhitong Nujia Honey Paste extraction on focal cerebral ischemia and its regulation mechanism.Methods]Totally 60 SPF SD male rats were randomly divided into sham group,model group,low-does extraction group,high-does extraction group and high does extraction+P13K specific inhibitor LY294002 group,with 12 rats in each group.Permanent middle cerebral artery occlusion model was established after an intracerebroventricular injection of LY294002 for 30 minutes.The neurological impairment score of each group was observed.The percentage of cerebral infarction area in rats was detected by TTC staining.The content of oxidative stress index in rat brain tissue was detected.The protein expression of p-Akt、NF-κB and Nrf2 in cerebral ischemic tissue side were detected by Western Blot.Results]Compared with model group,neurological impairment score in extraction group was significantly decreased;The volume of cerebral infarction was significantly decreased;In brain tissue,the content of SOD was increased and the content of TNF-αwas decreased.Extraction group up-regulated the proteins expression of p-Akt and Nrf2 and down-regulate NF-κB.The difference was statistically significant.Compared with extraction group,after injecting LY294002,neuroprotective effect was inhibited.Conclusion]Zhitong Nujia Honey Paste extraction has a brain protective effect on permanent focal cerebral ischemia injury rats.It can improve nerve injury,reduce the volume of cerebral infarction,activate the PI3K/Akt signaling pathway,regulate the expression of p-Akt,Nrf2,NF-κB protein,inhibit oxidative stress response,inflammatory reaction and nerve cell apoptosis,finally to prevent brain cell damage.