蒙古黄芪是一种传统中药，广泛用于治疗气虚、病毒或细菌感染、炎症和癌症。其中，蒙古黄芪中的一种重要活性成分——黄芪苷IV（AST）已被证明能通过抑制氧化应激和炎症的发生来减缓疾病进展。然而，AST在改善氧化应激方面的具体靶点和作用机制仍不清楚。 本研究旨在探讨AST改善氧化应激的靶点和机制，并阐明氧化应激的生物过程。研究设计了AST功能探针来捕获靶蛋白，并与蛋白质谱结合分析靶蛋白。使用小分子和蛋白质相互作用技术验证作用模式，使用计算机动力学模拟技术分析与靶蛋白的相互作用位点。在LPS诱导的急性肺损伤小鼠模型中评估AST改善氧化应激的药理活性。此外，使用药理学和分子生物学方法探索其作用机制。 研究发现，AST通过靶向PRDX6中的PLA2催化三元袋来抑制PLA2活性。这种结合改变了PRDX6的构象和结构稳定性，并干扰了PRDX6与RAC之间的相互作用，从而阻碍了RAC-GDI异二聚体的激活。RAC的失活防止了NOX2的成熟，减轻了超氧阴离子的产生，并改善了氧化应激损伤。 本研究结果表明，AST通过作用于PRDX6的催化三元袋来阻碍PLA2活性。这进而破坏了PRDX6与RAC之间的相互作用，从而阻碍了NOX2的成熟，减轻了氧化应激损伤。版权所有©2023 Elsevier GmbH出版。

Radix Astragali Mongolici, as a traditional Chinese medicine, is widely used in the treatment of qi deficiency, viral or bacterial infection, inflammation and cancer. Astragaloside IV (AST), a key active compound in Radix Astragali Mongolici, has been shown to reduce disease progression by inhibiting oxidative stress and inflammation. However, the specific target and mechanism of action of AST in improving oxidative stress are still unclear.This study aims to explore the target and mechanism of AST to improve oxidative stress, and to explain the biological process of oxidative stress.AST functional probes were designed to capture target proteins and combined with protein spectrum to analyze target proteins. Small molecule and protein interaction technologies were used to verify the mode of action, while computer dynamics simulation technology was used to analyze the site of interaction with the target protein. The pharmacological activity of AST in improving oxidative stress was evaluated in a mouse model of acute lung injury induced by LPS. Additionally, pharmacological and serial molecular biological approaches were used to explore the underlying mechanism of action.AST inhibits PLA2 activity in PRDX6 by targeting the PLA2 catalytic triad pocket. This binding alters the conformation and structural stability of PRDX6 and interferes with the interaction between PRDX6 and RAC, hindering the activation of the RAC-GDI heterodimer. Inactivation of RAC prevents NOX2 maturation, attenuates superoxide anion production, and improves oxidative stress damage.The findings of this research indicate that AST impedes PLA2 activity by acting on the catalytic triad of PRDX6. This, in turn, disrupts the interaction between PRDX6 and RAC, thereby hindering the maturation of NOX2 and diminishing the oxidative stress damage.Copyright © 2023. Published by Elsevier GmbH.