Oxymatrine alleviates cerebral ischemia-reperfusion injury by inhibiting microglia ferroptosis via NRF2 pathway activation

  • Phytomedicine. 2026 Jun 17:159:158450. doi: 10.1016/j.phymed.2026.158450.
Nanding Wu  1 ,  Yutong Wang  2 ,  Mengjie Guo  2 ,  Ruili Ran  2 ,  Dewei Wang  2 ,  Junqiu Song  2 ,  Lishan Hui  3 ,  Jing Yang  4 ,  Yue Yang  5
Affiliations
  • 1. Department of Clinical Laboratory Medicine, Affiliated Hospital of Inner Mongolia Minzu University, No. 1742 Huolinhe Street, Horqin District, Tongliao, Inner Mongolia 028000, China; Department of Biochemistry and Molecular Biology, Basic Medical College, Jinzhou Medical University, No.40, Section 3 Songpo Road, Linghe District, Jinzhou, Liaoning 121001, China.
  • 2. Department of Biochemistry and Molecular Biology, Basic Medical College, Jinzhou Medical University, No.40, Section 3 Songpo Road, Linghe District, Jinzhou, Liaoning 121001, China.
  • 3. Department of Clinical Laboratory Medicine, Affiliated Hospital of Inner Mongolia Minzu University, No. 1742 Huolinhe Street, Horqin District, Tongliao, Inner Mongolia 028000, China.
  • 4. Department of Biochemistry and Molecular Biology, Basic Medical College, Jinzhou Medical University, No.40, Section 3 Songpo Road, Linghe District, Jinzhou, Liaoning 121001, China; Provincial Key Laboratory of Cardiovascular and Cerebrovascular Drug Basic Research, Jinzhou Medical University, No.40, Section 3 Songpo Road, Linghe District, Jinzhou, Liaoning 121001, China.
  • 5. Department of Orthopedic Surgery, Shengjing Hospital of China Medical University, No.36 SanHao Street, HePing District, ShenYang, Liaoning 110000, China. Electronic address: [email protected].
PMID: 42322761 DOI: 10.1016/j.phymed.2026.158450
Abstract

Background: Cerebral ischemia-reperfusion injury (CIRI) involves secondary damage following blood flow restoration. Ferroptosis, an iron-dependent cell death process, is implicated in CIRI, with mitochondrial dynamics imbalance playing a critical role. Oxymatrine (OMT), a quinolizidine alkaloid extracted from the root of Sophora flavescens, exhibits neuroprotective properties, yet its role in modulating microglia Ferroptosis and mitochondrial homeostasis during CIRI remains unclear.

Purpose: This study aimed to investigate whether OMT attenuates microglia Ferroptosis in CIRI by activating the nuclear factor erythroid 2-related factor 2 (NRF2) pathway and restoring mitochondrial dynamic balance.

Methods: Using a rat middle cerebral artery occlusion/reperfusion model and BV-2 microglia under oxygen-glucose deprivation/reoxygenation, we evaluated the effects of OMT alone or with NRF2 inhibitor ML385 or Ferroptosis inducer Erastin. Assessments included neurological scores, infarct volume, Reactive Oxygen Species, ferrous iron, malondialdehyde, glutathione, mitochondrial membrane potential, and related protein expression, including NRF2, kelch-like ECH-associated protein 1 (KEAP1), heme oxygenase-1, solute carrier family 7 member 11, ferritin heavy chain, Glutathione Peroxidase 4, dynamin-related protein 1, optic atrophy 1. Molecular docking, surface plasmon resonance, and co-immunoprecipitation were used to examine OMT-KEAP1 binding. Finally, in vitro rescue experiments using KEAP1 overexpression and CDDO-ME (a specific KEAP1 inhibitor) confirmed the KEAP1/NRF2 dependency by re-assessing cell viability and Ferroptosis markers.

Results: OMT improved neurological outcomes and suppressed Ferroptosis in vivo and in vitro. Mechanistically, OMT disrupted Keap1-Nrf2 binding, promoting NRF2 nuclear translocation and upregulating solute carrier family 7 member 11, heme oxygenase-1, ferritin heavy chain, and Glutathione Peroxidase 4. This restored mitochondrial homeostasis by balancing optic atrophy 1 and dynamin-related protein 1, thereby reducing lipid peroxidation. Crucially, these effects were abolished by ML385 or Erastin, while KEAP1 overexpression and CDDO-ME respectively mimicked KEAP1-mediated suppression and NRF2-driven protection. These findings confirm OMT acts via a KEAP1/NRF2-dependent anti-ferroptotic axis.

Conclusions: OMT protects against CIRI by inhibiting microglia Ferroptosis through NRF2 pathway activation and improvement of mitochondrial homeostasis, supporting its potential as a therapeutic agent for ischemic stroke.

Keywords
Cerebral ischemia-reperfusion injury; Ferroptosis; Microglia; Mitochondrial dynamics; Oxymatrine.
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