BACKGROUND: Impairment of the intracranial lymphatic drainage system significantly contributes to Alzheimer's disease (AD) by facilitating the accumulation of neurotoxic amyloid-β (Aβ) and tau proteins. Restoring lymphatic function offers a promising preventive strategy against early-stage AD pathology.
PURPOSE: This study aimed to evaluate the effects and mechanisms of Cerebralcare Granule® (CG), a traditional Chinese medicine formula, on cognitive impairment and pathological markers in AD mouse models by modulating intracranial lymphatic clearance pathways.
METHODS: Six-month-old APP/PS1 transgenic mice and wild-type controls received oral administration of CG or donepezil for two months. Behavioral assessments included the Morris water maze, open field, Y-maze, novel object recognition, and passive avoidance tests. Immunohistochemistry, immunofluorescence, and Western blot analyses were used to assess Aβ deposition, glymphatic clearance, astrocytic aquaporin-4 (AQP4) polarization, meningeal lymphangiogenesis, and blood-brain barrier integrity. Tracer-based in vivo imaging confirmed improved CSF influx and efflux dynamics. Brain-penetrant compounds of CG were identified using UPLC-MS/MS, MALDI-TOF-MS imaging, and network pharmacology.
RESULTS: CG treatment significantly improved cognitive performance, reduced Aβ burden, enhanced glymphatic transport, and promoted meningeal lymphatic drainage in APP/PS1 mice. CG restored perivascular AQP4 polarization, improved cerebrospinal fluid-interstitial fluid exchange, facilitated waste removal to cervical lymph nodes, and protected the integrity of the blood-brain barrier. Major brain-penetrant compounds-paeoniflorin, rhynchophylline, and ethyl gallate-were found to target lymphatic signaling pathways (AQP4, VEGFC, VEGFR3, PROX1) effectively.
CONCLUSION: CG exerts protective effects against cognitive impairment and AD pathology by reinforcing the structural and functional integrity of the intracranial lymphatic drainage system, highlighting a novel therapeutic avenue for proactive brain health management in early-stage AD.
