金丝桃苷保护大鼠脑缺血再灌注损伤的机制研究

Study on Mechanism of Hyperoside Protecting Cerebral Ischemia Reperfusion Injury in Rats

关键词:  金丝桃苷|脑缺血再灌注|抗炎|抗凋亡|TLR4/COX-2信号通路

Key words:  hypericin|brain tissue of cerebral ischemia-reperfusion|anti-inflammatory|anti-apoptosis|TLR4/COX-2 signaling pathway

摘要:

目的 探究金丝桃苷（hyperoside，Hyp）对脑缺血再灌注大鼠脑组织的保护作用及相关机制。方法 采用线栓法建立大脑中动脉闭塞/再灌注（middle cerebral artery occlusion/reperfusion，MCAO/R）大鼠模型，分成假手术组、模型组、Hyp低、中、高剂量组（30，60，120 mg·kg^-1）。持续给药14 d后，采用Zea Longa法对大鼠进行神经功能评分，并测定脑含水量。TTC染色法测定大鼠脑梗死体积，ELISA检测炎症相关因子，HE染色观察大脑海马CA1区神经元病理形态，TUNEL染色观察大鼠脑组织细胞凋亡程度，Western blotting检测TLR4和COX-2以及凋亡相关蛋白的表达。结果 Hyp干预能够显著改善MCAO/R大鼠Zea Longa评分（P<0.05），减少脑含水量和脑梗死体积，显著降低炎症因子（TNF-α、IL-1β、IL-6、ICAM-1以及VCAM-1）的表达（P<0.05或P<0.01），并且有效改善海马CA1区神经元的病理学改变和凋亡情况，显著抑制TLR4、COX-2、NF-kB、caspase-3、caspase-9以及Bax蛋白的表达（P<0.05或P<0.01），上调Bcl-2蛋白的表达（P<0.05）。结论 Hyp对脑缺血再灌注损伤的保护作用与抗炎、抗凋亡以及抑制TLR4/COX-2信号通路有关。

Abstract:

OBJECTIVE To investigate the protective effect and mechanism of hyperoside(Hyp) on brain tissue of cerebral ischemia-reperfusion rats. METHODS Rat models of middle cerebral artery occlusion/reperfusion(MCAO/R) were established by bolt-line method and divided into sham operation group, model group and Hyp low, medium and high dose group(30, 60, 120 mg·kg^-1). The rats were evaluated by Zea Longa for neurological function and the brain water content was measured. The volume of cerebral infarction in rats was determined by TTC staining, inflammatory factors were detected by ELISA, pathological morphology of neurons in the hippocampus CA1 was observed by HE staining, apoptosis of brain cells was observed by TUNEL staining, and the expressions of TLR4, COX-2 and apoptosis-related proteins were detected by Western blotting. RESULTS Hyp intervention could significantly improve the Zea Longa score of MCAO/R rats(P<0.05), reduce brain water content and cerebral infarction volume, significantly reduce the expression of inflammatory factors(TNF-α, IL-1β, IL-6, ICAM-1, VCAM-1)(P<0.05 or P<0.01), effectively improve the pathological blood changes and apoptosis of neurons in the hippocampus CA1 region, significantly inhibit the expression of TLR4, COX-2, NF-kB, caspase-3, caspase-9 and Bax protein (P<0.05 or P<0.01), and upregulated the expression of Bcl-2 protein(P<0.05). CONCLUSION The protective effect of Hyp on cerebral ischemia-reperfusion injury is related to anti-inflammatory, anti-apoptotic and inhibition of TLR4/COX-2 signaling pathway.