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.