Integrated network pharmacology and brain metabolomics to analyze the mechanism of Dihuang Yinzi intervention in Alzheimer's disease.

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer's disease (AD) is an incurable neurodegenerative disease that has become one of the most important diseases threatening global public health security. Dihuang Yinzi (DHYZ) is a traditional Chinese medicine that has been widely used for the treatment of AD and has significant therapeutic effects, but its specific mechanism of action is still unclear.The aim of the study is to investigate the specific mechanism of DHYZ in treating AD based on brain metabolomics and network pharmacology.

MATERIALS AND METHODS

In this study, the classic APPswe/PS1E9 (APP/PS1) mice were selected as the AD animal model, and the mechanism of DHYZ was studied. The learning and memory ability of mice was detected by Y-maze test, and the ultrastructure of neural cells in the brain of the mice was observed by transmission electron microscope (TEM). Then, the mechanism of DHYZ intervention in AD was analyzed by constructing network pharmacology, and combined with brain metabolomics based on ultra performance liquid chromatography-mass spectrometry (UPLC-MS) to detect differential metabolic markers and their metabolic pathways. In addition, a joint analysis of differential metabolites and potential targets for DHYZ treatment of AD is conducted to deeply explore the relationship between key targets, differential metabolites, and metabolic pathways.

RESULTS

After 30 days of DHYZ treatment, the spatial work and reference memory ability of APP/PS1 mice were significantly improved, the structure of mitochondria and synapses in the neurons of the brain were basically normal. 202 potential targets for DHYZ treatment of AD were screened through network pharmacology, and after enrichment analysis, these targets showed correlation with redox reactions, mitochondrial and synaptic functional pathways. And 7 differential metabolites were identified in brain metabolomics are Nicotinic acid, N-Formyl-L-glutamic acid, 5-(2-Hydroxyethyl)-4-methylthiazole, D-Gulono-1,4-lactone, Norepinephrine, 3-Methylotrophicacid, Palmitic acid. These differential metabolites mainly involve nicotinite and nicotinamide metabolism, pertussis, cAMP signaling pathway, cysteine and methionine metabolism. Notablely, through matching analysis of targets and metabolites, a total of 20 genes were found to match Nicotinic acid, 51 genes were found to match norepinephrine, and 14 genes intersected with the two metabolites, enrichment analysis of the intersected genes showed that neuroactive light receptor interaction, serotonergic synapse, and cAMP signaling were significantly affected, which is consistent with previous network pharmacology results.

CONCLUSION

This study identified the main chemical ingredients of DHYZ intervention in AD may originated from Wild, Line and (L.f) Ker-Gawl. Combined with Y Maze, TEM and brain metabolomics, revealed that DHYZ can improve the learning and memory abilities and brain pathological morphology of APP/PS1 mice by regulating nicotinic acid, 3-Methylthiopropionic acid, pertussis and their metabolic pathways, including nicotinate and nicotinamide metabolism, cAMP signaling pathway and cysteine and methionine metabolism. In short, this study provides a new research foundation and direction for the treatment of AD with traditional Chinese medicine.