Buyang Huanwu decoction promotes neurological recovery after ischemic stroke by activating the Akt/PAK5/SNPH axis to enhance mitochondrial recruitment and axonal remodeling.

ETHNOPHARMACOLOGICAL RELEVANCE: Buyang Huanwu Decoction (BHD), a classic formula in Chinese medicine, has demonstrated neuroprotective properties in numerous studies on ischemic stroke. However, the specific mechanisms through which BHD promotes neurological recovery during the recovery phase, particularly those linked to axonal remodeling, have yet to be fully elucidated.

AIM OF THE STUDY: This study is designed to investigate potential molecular and cellular mechanisms responsible for the beneficial effects of BHD in ischemic stroke.

MATERIALS AND

METHODS

Characterization of the major chemical constituents in BHD was performed using High-Performance Liquid Chromatography with Ultraviolet Detection (HPLC-UV). A mouse model of ischemic stroke was established by subjecting male C57BL/6 mice to middle cerebral artery occlusion (MCAO). Functional recovery was assessed with the Longa score, cylinder test, and balance beam test. Quantification of brain tissue injury involved 2,3,5-Triphenyltetrazolium Chloride (TTC) staining, Hematoxylin and Eosin (HE) staining, TUNEL staining, Nissl staining, electron microscopy (EM), and laser speckle contrast imaging (LSCI). For mechanistic exploration, we employed network pharmacology, transcriptome sequencing (RNA-seq), immunohistochemistry (IHC), Western blot (WB), immunofluorescence, co-immunoprecipitation (Co-IP), molecular docking, and surface plasmon resonance (SPR) analyses.

RESULTS

BHD significantly relieved post-ischemic stroke neurological deficits by enhancing axonal remodeling. BHD treatment lowered infarct volume, curtailed neuronal apoptosis, and upheld neuronal integrity within the ischemic brain. It also improved mitochondrial function and energy metabolism, reflected by increased ATP levels and normalized mitochondrial ultrastructure. Concomitantly, BHD augmented mitochondrial recruitment to axonal compartments, linking mitochondrial dynamics to axonal repair. Mechanistically, BHD triggered the PAK5/SNPH signaling cascade, which augmented mitochondrial recruitment to injured axons and thus facilitated axonal repair. This triggering was mediated by Akt. Inhibition of Akt abrogated both the neuroprotection and the mitochondrial recruitment induced by BHD, highlighting the critical role of the Akt/PAK5/SNPH pathway in mediating BHD's therapeutic efficacy.

CONCLUSION

BHD enhances post-stroke neural recovery via activation of the Akt/PAK5/SNPH pathway, which boosts mitochondrial recruitment to damaged axons and facilitates axonal remodeling. These insights elucidate the mechanism underlying BHD's neuroprotective role in the recovery phase of ischemic stroke.