Cerebral ischemic-reperfusion injury (CIRI) involves mitochondrial dysfunction, with mitophagy playing a key role. Astragaloside IV (AS-IV) shows neuroprotective potential; however, its mechanisms related to mitochondrial function and apoptosis remain unclear. Methods: Using a rat MCAO/R model, we evaluated the AS-IV’s effects via neurological scores, TTC staining, and histopathology. Molecular assays and docking were used to analyze mitophagy (PINK1, Parkin, p62, ROS, Bcl-2, and BAX) and apoptosis markers. Results: AS-IV improved neurological function, reduced infarct volume, and alleviated neuronal/mitochondrial damage. It upregulated PINK1/Parkin, decreased p62, and modulated Bcl-2/Bax. Docking confirmed AS-IV binds PINK1/Parkin with high affinity. Conclusions: AS-IV protects against CIRI by regulating the PINK1/Parkin pathway, improving mitochondrial function, and inhibiting neuronal apoptosis, providing an experimental basis for the clinical use

Background: Neuronal apoptosis is the core pathological mechanism of cerebral ischemic–reperfusion injury (CIRI); although Astragaloside IV (AS-IV) has demonstrated neuroprotective activity against CIRI, its specific molecular mechanisms underlying the regulation of this apoptosis-related pathway remain to be systematically elucidated. Methods: We establish an in vivo model of middle cerebral artery occlusion/reperfusion (MCAO/R) in rats and an in vitro model of oxygen–glucose deprivation/reperfusion (OGD/R) in PC12 cells. Six core apoptotic proteins, including CytC, Apaf-1, BAX, Bcl-2, Caspase3, and Caspase9, were detected using neurological function scoring, TTC/HE/Nissl staining, TUNEL staining, Western blot, and immunofluorescence techniques. Molecular docking and molecular dynamics simulation were utilized to analyze the binding affinity between AS-IV and the aforementioned apoptotic proteins. Results: Molecular docking and dynamics simulation demonstrated AS-IV stably binds six core apoptotic proteins, and comparative analysis with target-specific reference ligands identified Apaf-1 as its primary target with the most favorable binding properties. In rat MCAO/R models, AS-IV alleviated neurological deficits, reduced cerebral infarct volume and improved brain pathological damage; in PC12 cell OGD/R models, it decreased neuronal apoptosis. Western blot and immunofluorescence confirmed AS-IV downregulated pro-apoptotic proteins (cytoplasmic CytC, Apaf-1, BAX, cleaved-Caspase9/3) and upregulated anti-apoptotic Bcl-2. Conclusions: This study clarifies the anti-apoptotic molecular mechanism of AS-IV, it alleviates CIRI by targeting the CytC/Apaf-1 mitochondrial apoptotic pathway.

Background: Ischemic stroke triggers persistent neuroinflammation, microglial activation, and peripheral immune changes that aggravate secondary brain injury. Astragaloside IV (AS-IV), a major bioactive constituent of Astragalus membranaceus , has neuroprotective and immunomodulatory effects, but its influence on Tregs and CD86/CD206-associated microglial phenotypic responses remains unclear. Aim: This study investigated whether AS-IV attenuates post-ischemic neuroinflammation in association with Treg-related immune responses, PI3K/AKT signaling alterations, and CD86/CD206-associated brain myeloid phenotypic responses. Materials and methods: A mouse middle cerebral artery occlusion (MCAO) model was established using the intraluminal filament method. Neurological deficits, infarct volume, and histopathological injury were evaluated after AS-IV treatment. Western blotting and ELISA were used to assess inflammatory cytokines and PI3K/AKT-associated signaling in ischemic brain tissue. Transcriptomic analysis identified AS-IV-related biological processes and pathways. Flow cytometry quantified CD4 ⁺ CD25 ⁺ FOXP3 ⁺ regulatory populations and additionally analyzed CD4 ⁺ FOXP3 ⁺ populations in the spleen and cervical lymph nodes, together with CD86 ⁺ /CD206 ⁺ phenotypic responses within the CD11b ⁺ CD45^low/int population in brain tissue. Immunofluorescence evaluated brain CD3 ⁺ FOXP3 ⁺ signals and Iba1/CD86 or Iba1/CD206 double-positive signals. Anti-CD25 intervention was used to evaluate the involvement of Treg-related immune responses in AS-IV-associated effects. Results: AS-IV reduced infarct volume, showed a trend toward improvement in neurological deficit scores, and alleviated histopathological injury after MCAO. It decreased IL-6 and TNF-α and increased IL-10 and TGF-β in ischemic brain tissue. Transcriptomic analysis identified changes associated with the PI3K/AKT signaling pathway and immune regulatory processes, while western blotting showed increased p-PI3K/PI3K and p-AKT/AKT ratios after AS-IV treatment. AS-IV increased Treg proportions in the spleen and cervical lymph nodes and increased CD3 ⁺ FOXP3 ⁺ signals in brain tissue. It also reduced CD86 ⁺ -associated and increased CD206 ⁺ -associated brain myeloid phenotypic responses. Anti-CD25 partially attenuated AS-IV-associated improvements in neurological and brain injury outcomes, as well as its effects on inflammatory cytokines and brain myeloid phenotypic responses. Conclusion: AS-IV attenuated post-ischemic neuroinflammation in association with Treg-related immune responses and PI3K/AKT-associated signaling alterations, accompanied by changes in CD86/CD206-associated brain myeloid phenotypic responses. These findings support AS-IV as a potential neuroimmunomodulatory intervention for ischemic stroke.