Mao Mingjiang, Cao Xingqin, Liang Yuhua, Li Qiuying, Chen Simiao, Zhou Liping, Zhang Yuyan, Guo Ying
School of Life Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, PR China.
School of Life Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, PR China.
Phytomedicine. 2024 Apr;126:155254. doi: 10.1016/j.phymed.2023.155254. Epub 2024 Feb 1.
The gut-brain axis (GBA) plays a central role in cerebral ischaemia-reperfusion injury (CIRI). Rhubarb, known for its purgative properties, has demonstrated protective effects against CIRI. However, it remains unclear whether this protective effect is achieved through the regulation of the GBA.
This study aims to investigate the mechanism by which rhubarb extract improves CIRI by modulating the GBA pathway.
We identified the active components of rhubarb extract using LC-MS/MS. The model of middle cerebral artery occlusion (MCAO) was established to evaluate the effect of rhubarb extract. We conducted 16S rDNA sequencing and untargeted metabolomics to analyze intestinal contents. Additionally, we employed HE staining, TUNEL staining, western blot, and ELISA to assess intestinal barrier integrity. We measured the levels of inflammatory cytokines in serum via ELISA. We also examined blood-brain barrier (BBB) integrity using Evans blue (EB) penetration, transmission electron microscopy (TEM), western blot, and ELISA. Neurological function scores and TTC staining were utilized to evaluate neurological outcomes.
We identified twenty-six active components in rhubarb. Rhubarb extract enhanced α-diversity, reduced the abundance of Enterobacteriaceae, and partially rectified metabolic disorders in CIRI rats. It also ameliorated pathological changes, increased the expressions of ZO-1, Occludin, and Claudin 1 in the colon, and reduced levels of LPS and d-lac in serum. Furthermore, it lowered the levels of IL-1β, IL-6, IL-10, IL-17, and TNF-α in serum. Rhubarb extract mitigated BBB dysfunction, as evidenced by reduced EB penetration and improved hippocampal microstructure. It upregulated the expressions of ZO-1, Occludin, Claudin 1, while downregulating the expressions of TLR4, MyD88, and NF-κB. Similarly, rhubarb extract decreased the levels of IL-1β, IL-6, and TNF-α in the hippocampus. Ultimately, it reduced neurological function scores and cerebral infarct volume.
Rhubarb effectively treats CIRI, potentially by inhibiting harmful bacteria, correcting metabolic disorders, repairing intestinal barrier function, alleviating BBB dysfunction, and ultimately improving neurological outcomes.
肠-脑轴（GBA）在脑缺血再灌注损伤（CIRI）中起核心作用。大黄以其泻下特性而闻名，已显示出对CIRI的保护作用。然而，这种保护作用是否通过调节GBA来实现仍不清楚。
本研究旨在探讨大黄提取物通过调节GBA途径改善CIRI的机制。
我们使用液相色谱-串联质谱（LC-MS/MS）鉴定大黄提取物的活性成分。建立大脑中动脉闭塞（MCAO）模型以评估大黄提取物的效果。我们进行16S核糖体DNA测序和非靶向代谢组学分析肠道内容物。此外，我们采用苏木精-伊红（HE）染色、末端脱氧核苷酸转移酶介导的缺口末端标记（TUNEL）染色、蛋白质印迹法和酶联免疫吸附测定（ELISA）来评估肠道屏障完整性。我们通过ELISA测量血清中炎症细胞因子的水平。我们还使用伊文思蓝（EB）渗透、透射电子显微镜（TEM）、蛋白质印迹法和ELISA检查血脑屏障（BBB）的完整性。利用神经功能评分和TTC染色评估神经学结果。
我们鉴定出大黄中的26种活性成分。大黄提取物增强了α多样性，降低了肠杆菌科的丰度，并部分纠正了CIRI大鼠的代谢紊乱。它还改善了病理变化，增加了结肠中紧密连接蛋白1（ZO-1）、闭合蛋白（Occludin）和Claudin 1的表达，并降低了血清中脂多糖（LPS）和D-乳酸（d-lac）的水平。此外，它降低了血清中白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）、白细胞介素-10（IL-10）、白细胞介素-17（IL-17）和肿瘤坏死因子-α（TNF-α）的水平。大黄提取物减轻了BBB功能障碍，表现为EB渗透减少和海马微观结构改善。它上调了ZO-1、Occludin、Claudin 1的表达，同时下调了Toll样受体4（TLR4）、髓样分化因子88（MyD88）和核因子κB（NF-κB）的表达。同样，大黄提取物降低了海马中IL-1β、IL-6和TNF-α的水平。最终，它降低了神经功能评分和脑梗死体积。
大黄可有效治疗CIRI，可能是通过抑制有害细菌、纠正代谢紊乱、修复肠道屏障功能、减轻BBB功能障碍并最终改善神经学结果来实现的。
