Oxymatrine alleviates severe acute pancreatitis via dual targeting of PKCα and NE to enforce cytosolic and nuclear blockade of NETosis.

BACKGROUND: Severe acute pancreatitis (SAP) is a life-threatening systemic inflammatory disorder with limited therapies. Recent evidence underscores the excessive formation of neutrophil extracellular traps (NETs) as a pivotal driver of SAP. Oxymatrine (OMT), the most active component in Sophora flavescens Aiton (SFA), has demonstrated potent anti-inflammatory properties, but whether it mitigates SAP by targeting NETs and the underlying mechanism remain unclear. METHODS: The pharmacological efficacy of OMT was evaluated in two SAP mouse models. Quantitative proteomics and network pharmacology were integrated to screen candidate pathways. OMT-target interactions were characterized using molecular docking, surface plasmon resonance (SPR) and cell thermal shift assay (CETSA). Mechanistic investigations were conducted in PMA-stimulated murine bone marrow neutrophils using specific inhibitor and agonist. RESULTS: OMT alleviated pancreatic damage and multi-organ dysfunction in SAP mice. Integrating quantitative proteomics and network pharmacology, we identified the inhibition of NET formation as the pivotal mechanism underlying OMT-mediated protection, which was further validated in vivo and in vitro. OMT directly binds to protein kinase C α (PKCα) and neutrophil elastase (NE) with high affinity and favorable kinetics. Mechanistically, OMT inhibited the PKCα/ROS/NE signaling axis, impeding NE nuclear translocation. Moreover, OMT upregulated class I histone deacetylases (HDACs) to stabilize nuclear chromatin in a PKCα-dependent manner, thereby counteracting chromatin decondensation and limiting NET release. CONCLUSION: This study indicates that OMT restores neutrophil homeostasis and inhibits NET formation by synergistically suppressing the PKCα/ROS/NE signaling cascade and impeding nuclear remodeling mediated by NE and class I HDACs. Our findings reveal OMT as a potent modulator of NETs and a promising candidate for SAP.