Department of Cardiology, Daqing People's Hospital, 213 Jianshe Road, Daqing, Heilongjiang 163319, China.
Department of Anesthesiology, Daqing People's Hospital, Daqing, Heilongjiang 163319, China.
Phytomedicine. 2019 Oct;63:153035. doi: 10.1016/j.phymed.2019.153035. Epub 2019 Jul 20.
Baicalin, which is isolated from Scutellariae Radix, has been shown to possess therapeutic potential for different diseases. Cardiac microvessel injury in myocardial ischemia-reperfusion (IR) has been extensively explored. However, there have been no studies investigating the physiological regulatory mechanisms of baicalin on nitric oxide production and the necroptosis of cardiac microvascular endothelial cells (CMECs) in myocardial IR injury. This study was designed to investigate the contribution of baicalin to repressing necroptosis and preventing IR-mediated CMEC dysfunction.
Indicators of ventricular structure and function were measured by an echocardiographic system. An MTT assay was performed to assess cell viability. Nitrite detection was performed to detect nitric oxide content, and cGMP content was determined using a commercially available cGMP complete ELISA kit. Morphology and molecular characteristics were detected by electron micrographs, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting.
Our results demonstrated that baicalin significantly improved cardiac function, decreased the myocardial infarction area, and inhibited myocardial cell apoptosis. Moreover, baicalin had a protective effect on cardiac microvessels and promoted the production of nitric oxide (NO) and the level of cGMP in rats that underwent myocardial IR injury. The results of the in vitro experiments showed that baicalin markedly improved cell activity and function in CMECs exposed to hypoxia-reoxygenation (HR). Further experiments indicated that baicalin supplementation suppressed the protein expression of RIP1, RIP3 and p-MLKL to interrupt CMEC necroptosis. In addition, baicalin promoted the production of NO via activating the PI3K-AKT-eNOS signaling pathway. Taken together, our results identified the PI3K-AKT-eNOS axis as a new pathway responsible for reperfusion-mediated microvascular damage.
Baicalin protected CMECs in IR rats by promoting the release of NO via the PI3K-AKT-eNOS pathway and mitigated necroptosis by inhibiting the protein expression of RIP1, RIP3 and p-MLKL.
黄芩苷是从黄芩中分离得到的，已被证明对多种疾病具有治疗潜力。心肌缺血再灌注（IR）中的心脏微血管损伤已被广泛研究。然而，目前还没有研究探讨黄芩苷对心肌 IR 损伤中心脏微血管内皮细胞（CMECs）中一氧化氮（NO）产生和坏死性凋亡的生理调节机制。本研究旨在探讨黄芩苷抑制坏死性凋亡和防止 IR 介导的 CMEC 功能障碍的作用。
采用超声心动图系统测量心室结构和功能指标。通过 MTT 法检测细胞活力。通过亚硝酸盐检测法检测 NO 含量，使用商业可得的 cGMP 完整 ELISA 试剂盒测定 cGMP 含量。通过电子显微镜、实时定量聚合酶链反应（qRT-PCR）和 Western blot 检测形态和分子特征。
我们的结果表明，黄芩苷显著改善了心脏功能，减少了心肌梗死面积，并抑制了心肌细胞凋亡。此外，黄芩苷对心肌 IR 损伤大鼠的心脏微血管具有保护作用，并促进了 NO 的产生和 cGMP 的水平。体外实验结果表明，黄芩苷明显改善了缺氧再复氧（HR）暴露的 CMEC 细胞的活性和功能。进一步的实验表明，黄芩苷通过抑制 RIP1、RIP3 和 p-MLKL 的蛋白表达来抑制 CMEC 坏死性凋亡。此外，黄芩苷通过激活 PI3K-AKT-eNOS 信号通路促进了 NO 的产生。综上所述，我们的研究结果确定了 PI3K-AKT-eNOS 轴是一种新的通路，负责再灌注介导的微血管损伤。
黄芩苷通过激活 PI3K-AKT-eNOS 通路促进 NO 的释放，通过抑制 RIP1、RIP3 和 p-MLKL 的蛋白表达来减轻 IR 大鼠的 CMEC 坏死性凋亡，从而保护 CMEC。
