富硒蛹虫草子实体多肽对SH-SY5Y细胞及脑缺血/再灌注损伤大鼠保护作用的机制研究

Protective Effects of Selenium-Rich Cordyceps sinensis Peptides on SH-SY5Y Cells and Cerebral Ischemia/Reperfusion Injury in Rats

目的:探讨富硒蛹虫草子实体多肽(SECM)对人神经母细胞瘤细胞SH-SY5Y和脑缺血/再灌注(I/R)损伤大鼠的保护作用机制。方法:以SECM含药血清为样品,通过噻唑蓝(MTT)法检测含药血清对SH-SY5Y细胞在半数抑制浓度(IC50)冈田酸和过氧化氢作用下对细胞增殖的影响,以观察SECM对SH-SY5Y细胞的保护修复作用;使用改进的推注线技术制备大鼠I/R损伤模型,24 h后进行神经功能评分,检测各组大鼠脑组织丙二醛(MDA)含量,超氧化物歧化酶(SOD)活性,谷胱甘肽-过氧化物酶(GSH-Px)活性,核转录因子(NF)-κB、血管内皮生长因子(VEGF)、细胞间黏附分子-1(ICAM-1)和纤溶酶原激活物抑制剂-1(PAI-1)表达水平。结果:过氧化氢和冈田酸对SH-SY5Y细胞的IC50分别为420、35 nmol·L^(-1),而SECM在IC50过氧化氢和冈田酸作用下对SH-SY5Y细胞具有很好的保护和修复作用;与假手术组比较,模型组大鼠神经功能损伤严重,脑组织中MDA含量和NF-κB、VEGF、PAI-1、ICAM-1表达水平均升高,GSH-Px及SOD活性均下降。与模型组比较,SECM高、中剂量组大鼠神经功能评分有所改善;SECM高、中、低剂量组大鼠脑组织中GSH-Px和SOD活性均上升,MDA含量和NF-κB、VEGF、PAI-1、ICAM-1表达水平均降低。结论:SECM对预先暴露于损伤因子过氧化氢及冈田酸的SH-SY5Y细胞均具有很好的保护和修复作用,同时对I/R损伤大鼠具有脑保护作用。

Objective:To study the protective mechanism of selenium-rich Cordyceps sinensis fruit-body polypeptide(SECM)on human neuroblastoma SH-SY5Y cells and cerebral ischemia/reperfusion(I/R)injury in rats.Methods:With SECM drug-containing serum as the sample,the effect of the drug-containing serum on the proliferation of SH-SY5Y cells under the action of okadaic acid and hydrogen peroxide at IC50 concentration was detected by methyl thiazolyl tetrazolium(MTT)method to observe the protective and repair effect of SECM on SH-SY5Y cells.A rat I/R injury model was created using a modified push-injection line technique,and neurological function tests of malonaldehyde(MDA),superoxide dismutase(SOD),glutathione-peroxidase(GSH-Px),nuclear transcription factor(NF)-κB,vascular endothelial growth factor(VEGF),intercellular adhesion molecule(ICAM)-1,and plasminogen activator inhibitor(PAI)-1 expressions in the brain tissue of rats were performed 24 hours later.Results:The IC50 concentrations of hydrogen peroxide and okadaic acid on SH-SY5Y cells were 420 nmol·L^(−1) and 35 nmol·L^(−1),respectively,while SECM had a good protective and repair effect on SH-SY5Y cells under the IC50 concentrations of hydrogen peroxide and okadaic acid.Compared with the shamoperated group,the model group had severe neurological function injury,with elevated expressions of MDA,NF-κB,VEGF,PAI-1,and ICAM-1 and decreased expressions of GSH-Px and SOD.Compared with that of the model group,the neurological function scores of the group with high and medium doses of SECM were improved.In the group with high,medium,and low doses of SECM,GSH-Px and SOD expressions were up-regulated,while MDA,NF-κB,VEGF,PAI-1,and ICAM-1 expressions were down-regulated.Conclusion:SECM can protect and repair SH-SY5Y cells exposed to hydrogen peroxide and okadaic acid in advance,and it can protect the brain of rats with I/R injury.