The molecular mechanisms of Guizhi Fuling Pills in ameliorating Alzheimer's disease-like cognitive impairment: insights from transcriptomics, metabolomics, and gut microbiome.

BACKGROUND: Alzheimer's disease (AD)-like cognitive impairment, as a major type of cognitive disorder, has witnessed a sharp rise in prevalence. Therefore, there is an urgent need to develop effective therapeutic intervention measures. Guizhi Fuling Pills (GFP), a classical Traditional Chinese Medicine (TCM) formula, has been shown to exert protective effects on cognitive function. However, its underlying mechanisms remain unclear. OBJECTIVE: To investigate the effects of GFP on AD-like cognitive impairment and elucidate its underlying mechanisms. METHODS: D-galactose (D-gal)-induced aged mice were used as the model. Mice were administered via gavage for 4 weeks with 0.9% normal saline (0.1 mL/10 g/d), low-dose GFP (12.56 g/kg/d), medium-dose GFP (25.11 g/kg/d), high-dose GFP (50.22 g/kg/d), and donepezil (5 mg/kg/d). A behavioral test was conducted using the Morris water maze. Histopathological changes were observed via H&E staining and immunohistochemistry (IHC). In addition, various methods such as transcriptomics, metabolomics, network pharmacology, and analysis of gut microbiota were utilized to elucidate the possible mechanisms. RESULTS: Guizhi Fuling Pills improved learning and memory function in aged mice, ameliorated hippocampal neuronal morphology, and reduced p-Tau protein deposition. Network pharmacology and hippocampal transcriptomic analyses suggested that the active components in GFP may ameliorate cognitive impairment through multiple mechanisms. It included regulation of the VEGF and PI3K/AKT signaling pathways, attenuation of inflammatory responses, inhibition of apoptosis, and repair of the blood-brain barrier (BBB). Gut microbiota analysis revealed that GFP modulated the compositional structure of the gut microbiota, including increasing the abundance of Lactobacillales and decreasing Desulfovibrionia and Tannerellaceae. Metabolomics suggested that GFP may ameliorate metabolic disorders in aged mice by modulating the synthesis of lipids and lipid-like molecules. CONCLUSION: The findings of this study suggest that GFP may ameliorate cognitive dysfunction in AD-like cognitive impairment mice through multiple mechanisms, including repair of the BBB, attenuation of inflammatory responses, and modulation of the gut microbiota and metabolic disorders.