Astragaloside IV attenuates post-ischemic neuroinflammation associated with Treg-related regulation of CD86/CD206-associated brain myeloid phenotypic responses and PI3K/AKT signaling alterations.

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 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 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 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.