Yuanzhi powder facilitated Aβ clearance in APP/PS1 mice: Target to the drainage of glymphatic system and meningeal lymphatic vessels

Exploring the pharmacological mechanism of Bu-Wang San on Alzheimer's disease through multiple GEO datasets of the human hippocampus, network pharmacology, and metabolomics based on GC-MS and UPLC-Q/TOF-MS

ETHNOPHARMACOLOGICAL RELEVANCE

Bu-Wang San (BWS) is a prominent traditional Chinese medicine known for calming the mind and promoting intelligence. It has been reported to improve learning and memory, enhance memory ability, and promote synaptic plasticity. However, the complexity of the material basis and the diversity of therapeutic targets of BWS on Alzheimer's disease (AD) have not been elucidated.

AIM OF THE STUDY

This study aimed to investigate the therapeutic material basis and the mechanism of BWS in AD treatment by comprehensively analyzing multiple GEO datasets of the human hippocampus, network pharmacology, and multi-platform metabolomics validation.

MATERIALS AND METHODS

Three GEO datasets of the human hippocampus were utilized to identify AD-associated targets using weighted gene co-expression network analysis (WGCNA) and differential analysis. Network pharmacology analyses were performed to investigate BWS's therapeutic material basis and predict the therapeutic targets of BWS on AD. A rat model was induced through the concurrent administration of AlCl3 and D-galactose to validate BWS's therapeutic potential and underlying mechanisms in AD. To validate the results of GEO data mining and network pharmacology, a comprehensive metabolomics approach integrating gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) was conducted on rat serum samples to uncover potential metabolic alterations and their associated pathways.

RESULTS

A total of 6367 genes were selected as AD drug targets through WGCNA analysis and enrichment analysis of disease-associated gene expression profiles in the GEO database. Network pharmacology was performed in this study for the identification of potential interactions between the components of BWS and its targets, TP53, STAT3, EGFR, MAOA, NOS3, PPARG, PRKCA, MAPK8, AChE, ARG1, among others, which were among the top 25 highest probable targets of BWS acting on AD. The multi-platform metabolomics indicated that amino sugar and nucleotide sugar metabolism, glycine, serine and threonine metabolism pathways, and other pathways may be associated with the AD model based on AlCl3 and D-galactose. The comparison of differential metabolites between the AD model group and the BWS intervention group revealed that 66 of the 97 differential metabolites exhibited a pullback trend, indicating a potential therapeutic effect of BWS on these metabolites.

CONCLUSION

This study builds a systematic strategy combining GEO datasets, network pharmacology, and multi-platform metabolomics and provides valuable insights into the pharmacological mechanism of BWS on AD. The results suggest that BWS may exert its therapeutic effects on AD by modulating the amino sugar and nucleotide sugar metabolism, glycerophospholipid metabolism, glycine, serine and threonine metabolism pathway and acting on the drug targets of ARG1, MAOA, AChE, XDH, GAD2, et al. This strategy provides a deep understanding of the molecular mechanisms of herbal medicine in treating AD at a systematic level.

Meningeal lymphatic drainage: novel insights into central nervous system disease

In recent years, increasing evidence has suggested that meningeal lymphatic drainage plays a significant role in central nervous system (CNS) diseases. Studies have indicated that CNS diseases and conditions associated with meningeal lymphatic drainage dysfunction include neurodegenerative diseases, stroke, infections, traumatic brain injury, tumors, functional cranial disorders, and hydrocephalus. However, the understanding of the regulatory and damage mechanisms of meningeal lymphatics under physiological and pathological conditions is currently limited. Given the importance of a profound understanding of the interplay between meningeal lymphatic drainage and CNS diseases, this review covers seven key aspects: the development and structure of meningeal lymphatic vessels, methods for observing meningeal lymphatics, the function of meningeal lymphatics, the molecular mechanisms of meningeal lymphatic injury, the relationships between meningeal lymphatic vessels and CNS diseases, potential regulatory mechanisms of meningeal lymphatics, and conclusions and outstanding questions. We will explore the relationship between the development, structure, and function of meningeal lymphatics, review current methods for observing meningeal lymphatic vessels in both animal models and humans, and identify unresolved key points in meningeal lymphatic research. The aim of this review is to provide new directions for future research and therapeutic strategies targeting meningeal lymphatics by critically analyzing recent advancements in the field, identifying gaps in current knowledge, and proposing innovative approaches to address these gaps.

Glymphatic system: a self-purification circulation in brain

The glymphatic system theory introduces a new perspective on fluid flow and homeostasis in the brain. Here, cerebrospinal fluid and interstitial fluid (CSF-ISF) moves from the perivascular spaces (PVS) of arteries to those of veins for drainage. Aquaporin-4 (AQP4) plays a crucial role in driving fluid within the PVS. The impairment to AQP4 is closely linked to the dysfunction of the glymphatic system. The function of the glymphatic system is less active during waking but enhanced during sleep. The efficiency of the glymphatic system decreases with aging. Damage to the glymphatic system will give rise to the development and progression of many brain diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), chronic traumatic encephalopathy (CTE), and vascular dementia (VaD). Here, we reviewed previous research associated with the glymphatic system, including its concepts, principles, and influencing factors. We hypothesize that AQP4 could be a target for the prevention and treatment of certain brain diseases through the regulation on the glymphatic system.

New perspectives on the glymphatic system and the relationship between glymphatic system and neurodegenerative diseases

Neurodegenerative diseases (ND) are characterized by the accumulation of aggregated proteins. The glymphatic system, through its rapid exchange mechanisms between cerebrospinal fluid (CSF) and interstitial fluid (ISF), facilitates the movement of metabolic substances within the brain, serving functions akin to those of the peripheral lymphatic system. This emerging waste clearance mechanism offers a novel perspective on the removal of pathological substances in ND. This article elucidates recent discoveries regarding the glymphatic system and updates relevant concepts within its model. It discusses the potential roles of the glymphatic system in ND, including Alzheimer's disease (AD), Parkinson's disease (PD), and multiple system atrophy (MSA), and proposes the glymphatic system as a novel therapeutic target for these conditions.

Spaceflight associated neuro-ocular syndrome: connections with terrestrial eye and brain disorders

Spaceflight Associated Neuro-ocular Syndrome (SANS) is a series of findings found in astronauts who have experienced long-duration spaceflight. It is characterized by neuro-ocular changes that may irreversibly alter vision and increase the risk for the development of terrestrial eye and brain disorders. Theories regarding its etiology and countermeasures to combat the findings seen continue to evolve. There is currently no direct treatment for SANS. Traditional Chinese Medicine (TCM) modalities have been used to treat eye and brain disorders on Earth that are pathogenically similar to SANS, therefore, TCM may be able to target corresponding pathology in astronauts, prevent and mitigate SANS findings, and decrease the risk for future development of disorders. This paper intends to discuss pathological similarities between SANS and terrestrial eye and brain disorders and how TCM has been used to treat those disorders.

Mechanism interpretation of Guhan Yangshengjing for protection against Alzheimer's disease by network pharmacology and molecular docking

ETHNOPHARMACOLOGICAL RELEVANCE

Guhan Yangshengjing (GHYSJ) is an effective prescription for delaying progression of Alzheimer's disease (AD) based on the ancient Chinese medical classics excavated from Mawangdui Han Tomb. Comprising a combination of eleven traditional Chinese herbs, the precise protective mechanism through which GHYSJ acts on AD progression remains unclear and has significant implications for the development of new drugs to treat AD.

AIM OF THE STUDY

To investigate the mechanism of GHYSJ in the treatment of AD through network pharmacology and validate the results through in vitro experiments.

MATERIALS AND METHODS

Chemical composition-target-pathway network and protein-protein interaction network were constructed by network pharmacology to predict the potential targets of GHYSJ for the treatment of AD. The interaction relationship between active ingredients and targets was verified by molecular docking and molecular force. Furthermore, the chemical constituents of GHYSJ were analyzed by LC-MS and HPLC, the effects of GHYSJ on animal tissues were analyzed by H&E staining. An Aβ-induced SH-SY5Y cellular model was established to validate the core pathways and targets predicted by network pharmacology and molecular docking.

RESULTS

The results of the network pharmacology analysis revealed a total of 155 bioactive compounds capable of crossing the blood-brain barrier and interacting with 677 targets, among which 293 targets specifically associated with AD, which mainly participated in and regulated the amyloid aggregation pathway and PI3K/Akt signaling pathway, thereby treating AD. In addition, molecular docking analysis revealed a robust binding affinity between the principal bioactive constituents of GHYSJ and crucial targets implicated in AD. Our findings were further substantiated by in vitro experiments, which demonstrated that Liquiritigenin and Ginsenosides Rh4, crucial constituents of GHYSJ, as well as GHYSJ pharmaceutic serum, exhibited a significant down-regulation of BACE1 expression in Aβ-induced damaged SH-SY5Y cells. This study provides valuable data and theoretical underpinning for the potential therapeutic application of GHYSJ in the treatment of AD and secondary development of GHYSJ prescription.

CONCLUSION

Through network pharmacology, molecular docking, LC-MS, and cellular experiments, GHYSJ was initially confirmed to delay the progression of AD by regulating the expression of BACE1 in Amyloid aggregation pathway. Our observations provided valuable data and theoretical underpinning for the potential therapeutic application of GHYSJ in the treatment of AD.