目的 探討人參皂苷Rb₁對小鼠腦缺血再灌注誘導(dǎo)的血腦屏障（BBB）損傷的作用及機制。方法 將C57BL/6小鼠隨機分為假手術(shù)組、模型組和人參皂苷Rb₁低、中、高劑量（5、10、20 mg·kg^-1）組，采用線栓法栓塞頸內(nèi)動脈1 h后復(fù)灌建立腦缺血再灌注損傷模型，假手術(shù)組不栓塞，其余操作同模型小鼠。缺血1 h后ip相應(yīng)藥物，于再灌注24 h后處死取材。采用伊文思藍(lán)染色法檢測各組小鼠BBB損傷程度；采用實時熒光定量PCR （qRT-PCR）法檢測各組小鼠腦組織中炎癥因子白細(xì)胞介素-1β（IL-1β）、白細(xì)胞介素-6（IL-6）、腫瘤壞死因子-α（TNF-α）以及緊密連接蛋白1（ZO-1）、閉合蛋白（Occludin）的mRNA表達(dá)水平；同時采用Western blotting檢測各組小鼠腦組織中ZO-1、Occludin蛋白，金屬基質(zhì)蛋白酶-2（MMP-2）、基質(zhì)金屬蛋白酶-9（MMP-9）以及MAPK通路相關(guān)蛋白磷酸化的表達(dá)水平。結(jié)果 與模型組相比，人參皂苷Rb₁可顯著減少腦缺血再灌注小鼠腦組織中伊文思藍(lán)的滲漏量（P<0.05），顯著降低腦組織中IL-1β、IL-6和TNF-α的mRNA轉(zhuǎn)錄水平（P<0.05、0.01）；顯著上調(diào)ZO-1和Occludin的mRNA轉(zhuǎn)錄和蛋白表達(dá)水平（P<0.05、0.01）；顯著降低MMP-2、MMP-9的蛋白表達(dá)水平（P<0.05、0.01）；顯著抑制MAPK通路p38、JNK及ERK磷酸化蛋白的表達(dá)（P<0.05、0.01）。結(jié)論 人參皂苷Rb₁對小鼠腦缺血再灌注誘導(dǎo)的BBB損傷具有一定的改善作用，其作用機制可能與抑制MAPK信號通路激活，減少MMP-2、MMP-9蛋白的表達(dá)，進而減輕對ZO-1、Occludin等緊密連接蛋白的降解有關(guān)。

Objective To explore the effects and underlying mechanisms of ginsenoside Rb₁ (Rb₁) on the blood-brain barrier (BBB) injury induced by cerebral ischemia reperfusion in mice. Methods C57BL/6J mice were randomly divided into sham operated group, model group, low, medium, high dose group of Rb₁ (5, 10, and 20 mg·kg^-1). This research used the middle cerebral artery occlusion and reperfusion (MCAO/R) animal model. After 1 h of ischemia and 24 h reperfusion, brain tissues of mice were extracted from executed mice. The evaluation of BBB damage in each group of mice was measured using Evans blue staining. The mRNA expression levels of the inflammatory factors-interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), as well as the expression of Zonula occludens-1 (ZO-1) and Occludin were examined in the brain tissues of mice by the qRT-PCR. Western blotting method was uesd to detect the expression levels of ZO-1, Occludin, Matrix metalloproteinase-2/9 (MMP-2/9), and MAPK related proteins in the brain tissue of each group of mice. Results Compared with the model group, Rb₁ significantly reduced the leakage of Evans blue in brain tissue of mice with cerebral ischemia-reperfusion (P< 0.05), and significantly reduced the mRNA transcription level of IL-1β, IL-6 and TNF-α in brain tissue (P< 0.05, 0.01), significantly upregulated the mRNA transcription and protein expression levels of ZO-1 and Occludin (P< 0.05, 0.01), significantly reduced the protein expression levels of MMP-2 and MMP-9 (P< 0.05, 0.01), significantly inhibited the expression of phosphorylated proteins p38, JNK, and ERK in the MAPK pathway (P< 0.05, 0.01). Conclusion Rb₁ can ameliorate BBB damage via inhibiting the activation of MAPK signal pathway, down-regulate the expression of MMP-2 and MMP-9, attenuate the degradation of ZO-1 and Occludin in MCAO/Rinduced mice.

R285.5

國家自然科學(xué)基金資助項目（81904028）