Cognitive Impairment in Parkinson's Disease: An Updated Overview Focusing on Emerging Pharmaceutical Treatment Approaches

α -Lipoic acid alleviates Parkinson's disease by suppressing S100A9-mediated pyroptosis

Parkinson's disease (PD) is a neurodegenerative disease, and inflammation is a key factor in the progression of PD. S100A9 mediates pyroptosis and implicates in various diseases including PD. Pyroptosis, an emerging form of programmed cell death, usually causes cell rupture and death via an inflammatory response. α-Lipoic acid (α-ALA), a cellular coenzyme, participates in anti-inflammatory and antioxidant processes. Although its role in PD has been confirmed, but the exact mechanism of its anti-inflammatory effect remains unclear. In our research, we examined the potential mechanisms of pyroptosis mediated by S100A9 in PD and the neuroprotective effects of α-ALA. We used 6-hydroxydopamine (6-OHDA) to induce SH-SY5Y cells in vitro and in C57BL/6 mice in vivo. The cell viability of SH-SY5Y cells confirmed the neuroprotective effect of α-ALA. Proteomics analysis indicated that S100A9 was involved in 6-OHDA-mediated neuronal injury, while α-ALA could inhibit. We found that α-ALA ameliorated PD symptoms induced by 6-OHDA and decreased the levels of NLRP3 inflammasome, Gasdermin D, and IL-1β, which are major hallmarks of pyroptosis. Furthermore, our research demonstrated that α-ALA mitigated cell injury by suppressing NLRP3-dependent pyroptosis mediated by S100A9. In brief, pyroptosis is pivotal in PD, while α-ALA protects dopaminergic neurons by suppressing pyroptosis mediated through the NLRP3 inflammasome, directly reducing S100A9, and subsequently inhibiting the NLRP3/Gasdermin D signaling pathways. Our results collectively suggest that suppressing S100A9-mediated pyroptosis and administering α-ALA may represent a novel approach in treating of PD.

Integrated network pharmacology, metabolomics, and microbiome studies to reveal the therapeutic effects of Anacyclus pyrethrum in PD-MCI mice

BACKGROUND

Anacyclus pyrethrum (l.) DC has potential value in treating Parkinson's disease (PD)-mild cognitive impairment (MCI), manifesting as impaired memory, attention, executive function, and language. However, the specific targets and modes of action of A. pyrethrum remain unclear.

PURPOSE

The aim of this study was to identify the active components of A. pyrethrum and examine their effectiveness in treating a mouse model of PD-MCI.

METHODS

We generated ethanol extracts of A. pyrethrum root (EEAP) and identified its active components and related targets using UHPLC-MS/MS and network pharmacology.The PD-MCI model was induced via intraperitoneal administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP). After following continuous administration of EEAP,Altered learning or memory, as well as anxiety, were tested using the morris water maze, eight-arm radial arm maze (RAM), and open-field test,elevated plus-maze. Brain histopathology and ultrastructural changes were examined using brightfield microscopy, and electron microscopy, respectively. Furthermore, protein expression was assessed using western blotting.Stool samples were used for metabolomics analysis by UHPLC-MS/MS and for 16S rDNA sequencing to determine the compositional changes of the gut microbiota.We conducted a short-chain fatty acid targeted metabolomics experiment to study their role in the gut-brain axis in PD-MCI.

RESULTS

Using UPLC-MS-MS, 126 compounds were identified from A. pyrethrum samples.After searching the databases and literature reports, 31 active components and 544 drug-disease targets were screened. Biological processes and molecular functions, such as energy channels, cell signaling, and metabolism, were discovered through GO analysis. The water maze experiment showed that the average swimming distance and escape latency of mice in EEAP groups decreased. The eight-arm maze experiment showed that model had a much higher number of errors related to working memory than the control mice. In the open field experiment, compared with the control group, the mice in the EEAP group exhibited an increase in the average movement speed and total movement distance, along with a decrease in the residence time.In the elevated plus maze, the control had less anxiety than the Model. Donepezil/Levodopa(D/l) mitigated anxiety-like behavior, and EEAP (100-400 mg/kg) showed a dose-dependent increase in open-arm metrics, suggesting it may ease anxiety in mice.Hippocampal tissue of mice treated with different doses of EEAP showed intact cellular layers and the hematoxylin-eosin-stained cones were slightly better;cells were arranged neatly; their morphology was normal, and were distributed uniformly. Electron microscopy revealed that the nuclear membrane, chromatin, and nucleoli were clearly demarcated in the hippocampus of mice treated with different doses of EEAP, contrary to that in the model group. In brain extracts of the EEAP group, lighter thinner bands for amyloid precursor protein (APP) and Aβ were observed compared to those in the model group. In model mice, APP and Aβ protein expression was higher than in the blank group, as shown by stronger bands. In EEAP-treated mice, the bands were weaker, indicating reduced expression. In the model group had lower Bcl-2 and higher Bax levels. EEAP treatment increased Bcl-2 and decreased Bax expression.Compared to the control group, the model showed substantially low glutathione peroxidase (GSH-Px),superoxide dismutase(SOD),catalase (CAT)activity (p < 0.05),much higher (p < 0.05) in the EEAP-H group than that in the model. EEAP intervention significantly modulated the fecal metabolic profile of PD-MCI mice. The abundance of steroid and lipid metabolites, including linoleylethanolamine, was markedly altered in the model group compared to the control group, with EEAP treatment reversing several of these abnormalities. PLS-DA and OPLS-DA revealed significant separation between groups (Q2= 0.542, p < 0.01), confirming a dose-dependent effect. Random forest analysis identified 15 key metabolic markers, such as dose-dependent changes in d-glutamine and hydrocodone. Metabolic pathway analysis demonstrated significant enrichment in phenylalanine, tyrosine, tryptophan metabolism, and arginine biosynthesis pathways (p < 0.05). The Support Vector Machine (SVM) model achieved an AUC approaching 1, indicating substantial differences in metabolite profiles. EEAP intervention significantly influenced the composition and functional profile of the intestinal microbiota. The Venn diagram illustrates that each group shared 342 operational taxonomic units (OTUs), with the EEAP 400 group exhibiting a distinct Bacteroidetes proportion. LEfSe analysis identified g_Prevotella as the characteristic bacterium in the control group, c_Epsilonproteobacteria in the model group, and g_Adlercreutzia in the EEAP 100 group. The Faith's Phylogenetic Diversity (PD) index was highest in the EEAP 100 group, and Non-metric Multidimensional Scaling (NMDS)/Principal Coordinates Analysis (PCoA) revealed significant differences in microbial community structure. Short-chain fatty acids (SCFAs) analysis indicated that acetic acid was the predominant metabolite, while EEAP dose-dependently regulated propionic acid and isovaleric acid levels (VIP > 1, p < 0.001). These findings demonstrate that EEAP exerts its regulatory effects by reshaping the structure and metabolic functions of the gut microbiota.

CONCLUSION

EEAP holds great promise as a potential therapeutic agent for PD-MCI, exerting its effects through multiple mechanisms, including regulating protein expression, modulating the fecal metabolic profile, and reshaping the gut microbiota and its metabolites.

The Correlation Between RIN3 Gene Methylation and Cognitive Impairment in Parkinson's Disease

Background

Parkinson's disease (PD) is the second most common neurodegenerative disorder, after Alzheimer's disease. Many individuals with PD experience cognitive impairment, significantly threatening both their physical and mental well-being. Research has shown that abnormal DNA methylation is closely linked to neurodegenerative conditions such as Alzheimer's and Parkinson's disease. The RIN3 gene, which encodes a guanine nucleotide exchange factor, plays a role in inhibiting amyloid-beta formation and affects protein endocytosis, both of which are linked to cognitive impairment. However, the potential connection between RIN3 gene methylation and cognitive impairment in Parkinson's disease has not yet been explored. This study aims to explore whether the methylation status of the RIN3 gene is connected to cognitive decline in Parkinson's patients, thereby shedding light on the gene's crucial role in the disease's development and identifying potential targets for diagnosing and treating cognitive impairment in this context.

Purpose

This study aims to explore whether the methylation status of the RIN3 gene is associated with cognitive impairment in Parkinson's disease and to further clarify the gene's significant role in the disease's pathogenesis.

Methods

This study involved 50 control subjects and 51 Parkinson's disease (PD) patients, who were assessed using a cognitive scale. Additionally, DNA methylation in whole blood was analyzed. The research compared RIN3 methylation levels between the PD group and the normal control group (NC), as well as between the subgroups of PD-Mild Cognitive Impairment (PD-MCI), PD-Normal Cognition (PD-NC), and the control group.

Results

The DNA methylation level of the RIN3 gene in the whole blood of patients with PD was lower than that in healthy controls (22.3%vs.23.6%, P=0.009). Moreover, individuals with PD-MCI had significantly lower RIN3 methylation levels than both the control group (21.3%vs.23.6%, P<0.001) and those in the PD-NC group (21.3%vs.23.3%, P=0.001).

Conclusion

RIN3 methylation is associated with PD-MCI. With appropriate lifestyle changes and clinical interventions, methylation may influence disease progression, suggesting that RIN3 gene methylation could serve as a predictor for the development of PD-MCI.

Current Progress on Postoperative Cognitive Dysfunction: An Update

Postoperative cognitive dysfunction (POCD) represents a significant clinical concern, particularly among elderly surgical patients. It is characterized by a decline in cognitive performance, affecting memory, attention, coordination, orientation, verbal fluency, and executive function. This decline in cognitive abilities leads to longer hospital stays and increased mortality. This review provides a comprehensive overview of the current progress in understanding the relevant pathogenic factors, possible pathogenic mechanisms, diagnosing, prevention and treatment of POCD, as well as suggesting future research directions. It discusses neuronal damage, susceptible genes, central cholinergic system, central nervous system (CNS) inflammation, stress response and glucocorticoids, and oxidative stress in the development of POCD, aiming to uncover the pathological mechanism and develop effective treatment strategies for POCD.

Towards multimodal cognition-based treatment for cognitive impairment in Parkinson's disease: drugs, exercise, non-invasive brain stimulation and technologies

PURPOSE OF REVIEW

Cognitive impairment is one of the most challenging non-motor symptoms of Parkinson's disease (PD) and may occur during all PD stages. There are no established pharmacological treatments for PD-related cognitive impairment, which may be improved by cognition-based interventions (i.e., cognitive stimulation, cognitive training, cognitive rehabilitation). Multimodal cognition-based interventions by adjunctive drugs, exercise, non-invasive brain stimulation and technologies may be effective in PD.

RECENT FINDINGS

Exercise combined with cognitive training may enhance global, memory, visuospatial and executive functioning, transcranial direct current stimulation delivered alongside cognitive training may improve attention and executive functioning, and exergames, semi-immersive virtual reality (VR) and telerehabilitation plus non-immersive VR combined with cognitive training may ameliorate global and executive functioning in PD patients.

SUMMARY

The evidence reviewed here, despite preliminary, is very encouraging and suggests strong rationale for combining pharmacological and non-pharmacological interventions with cognition-based treatments in PD. To overcome limitations of current studies, we propose some recommendations for future trials on drugs, exercise, non-invasive brain stimulation and technologies combined with cognition-based treatments for cognitive impairment in PD.

Efficacy and safety of hyperbaric oxygen therapy for Parkinson's disease with cognitive dysfunction: protocol for a systematic review and meta-analysis

INTRODUCTION

The presence of cognitive dysfunction notably affects the quality of life in individuals diagnosed with Parkinson's disease (PD) and is often recognised as a non-motor symptom. Comprehensive studies have shown the possible advantages of hyperbaric oxygen therapy (HBOT) in alleviating cognitive deficits in these individuals. This systematic review aims to investigate the practicality of incorporating HBOT within a more extensive therapeutic framework for PD, with a specific focus on cognitive symptoms.

METHODS AND ANALYSIS

A comprehensive literature review will be conducted utilising various databases such as PubMed and Cochrane Library and so on. The duration of the search will encompass the entire timeline from the initiation of each database up to 1 April 2024. This investigation seeks to uncover randomised controlled trials that explore the efficacy and safety of HBOT in patients with PD who are facing cognitive impairments. The authors' autonomous screening and extraction of data will facilitate the attainment of impartial results. The assessment of possible biases will be conducted using the Cochrane risk-of-bias tool, while statistical analyses will be executed with RevMan V.5.3 and Stata V.15.0.

ETHICS AND DISSEMINATION

As this review synthesises and evaluates previously conducted studies, the requirement for ethical approval is not applicable. The findings from this review will be shared via academic publications, comprehensive reports and presentations at pertinent conferences.

PROSPERO REGISTRATION NUMBER

CRD42024504763.

Mitochondrial Dysfunction in Parkinson's Disease: A Contribution to Cognitive Impairment?

Among the non-motor symptoms associated with Parkinson's disease (PD), cognitive impairment is one of the most common and disabling. It can occur either early or late during the disease, and it is heterogeneous in terms of its clinical manifestations, such as Subjective Cognitive Dysfunction (SCD), Mild Cognitive Impairment (MCI), and Parkinson's Disease Dementia (PDD). The aim of the present review is to delve deeper into the molecular mechanisms underlying cognitive decline in PD. This is extremely important to delineate the guidelines for the differential diagnosis and prognosis of the dysfunction, to identify the molecular and neuronal mechanisms involved, and to plan therapeutic strategies that can halt cognitive impairment progression. Specifically, the present review will discuss the pathogenetic mechanisms involved in the progression of cognitive impairment in PD, with attention to mitochondria and their contribution to synaptic dysfunction and neuronal deterioration in the brain regions responsible for non-motor manifestations of the disease.

Vagus nerve stimulation in Parkinson's disease: a scoping review of animal studies and human subjects research

Parkinson's Disease (PD) is a prevalent, progressive neurodegenerative disease with motor and non-motor symptoms. Vagus Nerve Stimulation (VNS) has emerged as a potential therapeutic approach for PD, but published research on this topic varies widely. This scoping review maps existing literature on VNS for PD, highlighting stimulation methods, operational parameters, safety profiles, neurophysiological mechanisms, and clinical outcomes in human and animal models. Online databases were used to identify 788 papers published between 2013 and 2023, from which 17 publications on invasive and non-invasive VNS in PD were selected. Studies showed high variability in VNS parameters and study design. Evidence in animal models and human subjects suggests potential neurophysiological effects on PD-related pathology and motor function improvements. However, significant gaps in the literature remain. Future research should include rigorous reporting of study design, standardization of stimulation parameters, and larger sample sizes to ultimately facilitate translation of VNS into clinical practice.

Golexanolone reduces glial activation in the striatum and improves non-motor and some motor alterations in a rat model of Parkinson's disease

Background

Parkinson's disease (PD) affects more than 6 million people worldwide. Along with motor impairments, patients and animal models exhibiting PD symptoms also experience cognitive impairment, fatigue, anxiety, and depression. Currently, there are no drugs available for PD that alter the progression of the disease. A body of evidence suggests that increased GABA levels contribute to the reduced expression of tyrosine hydroxylase (TH) and accompanying behavioral deficits. TH expression may be restored by blocking GABAA receptors. We hypothesized that golexanolone (GR3027), a well-tolerated GABAA receptor-modulating steroid antagonist (GAMSA), may improve Parkinson's symptoms in a rat model of PD.

Objectives

The aims of this study were to assess whether golexanolone can ameliorate motor and non-motor symptoms in a rat model of PD and to identify some underlying mechanisms.

Methods

We used the unilateral 6-OHDA rat model of PD. The golexanolone treatment started 4 weeks after surgery. Motor symptoms were assessed using Motorater and CatWalk tests. We also analyzed fatigue (using a treadmill test), anhedonia (via the sucrose preference test), anxiety (with an open field test), and short-term memory (using a Y maze). Glial activation and key proteins involved in PD pathogenesis were analyzed using immunohistochemistry and Western blot.

Results

Rats with PD showed motor incoordination and impaired locomotor gait, increased fatigue, anxiety, depression, and impaired short-term memory. Golexanolone treatment led to improvements in motor incoordination, certain aspects of locomotor gait, fatigue, anxiety, depression, and short-term memory. Notably, golexanolone reduced the activation of microglia and astrocytes, mitigated TH loss at 5 weeks after surgery, and prevented the increase of α-synuclein levels at 10 weeks.

Conclusions

Golexanolone may be useful in improving both motor and non-motor symptoms that adversely affect the quality of life in PD patients, such as anxiety, depression, fatigue, motor coordination, locomotor gait, and certain cognitive alterations.

Research on the signaling pathways related to the intervention of traditional Chinese medicine in Parkinson's disease:A literature review

ETHNOPHARMACOLOGICAL RELEVANCE

Parkinson's disease (PD) is the most common progressive neurodegenerative disorder affecting more than 10 million people worldwide and is characterized by the progressive loss of Daergic (DA) neurons in the substantia nigra pars compacta. It has been reported that signaling pathways play a crucial role in the pathogenesis of PD, while the active ingredients of traditional Chinese medicine (TCM) have been found to possess a protective effect against PD. TCM has demonstrated significant potential in mitigating oxidative stress (OS), neuroinflammation, and apoptosis of DA neurons via the regulation of signaling pathways associated with PD.

AIM OF THE REVIEW

This study discussed and analyzed the signaling pathways involved in the occurrence and development of PD and the mechanism of active ingredients of TCM regulating PD via signaling pathways, with the aim of providing a basis for the development and clinical application of therapeutic strategies for TCM in PD.

MATERIALS AND METHODS

With "Parkinson's disease", "Idiopathic Parkinson's Disease", "Lewy Body Parkinson's Disease", "Parkinson's Disease, Idiopathic", "Parkinson Disease, Idiopathic", "Parkinson's disorders", "Parkinsonism syndrome", "Traditional Chinese medicine", "Chinese herbal medicine", "active ingredients", "medicinal plants" as the main keywords, PubMed, Web of Science and other online search engines were used for literature retrieval.

RESULTS

PD exhibits a close association with various signaling pathways, including but not limited to MAPKs, NF-κB, PI3K/Akt, Nrf2/ARE, Wnt/β-catenin, TLR/TRIF, NLRP3, Notch. The therapeutic potential of TCM lies in its ability to regulate these signaling pathways. In addition, the active ingredients of TCM have shown significant effects in improving OS, neuroinflammation, and DA neuron apoptosis in PD.

CONCLUSION

The active ingredients of TCM have unique advantages in regulating PD-related signaling pathways. It is suggested to combine network pharmacology and bioinformatics to study the specific targets of TCM. This not only provides a new way for the prevention and treatment of PD with the active ingredients of TCM, but also provides a scientific basis for the selection and development of TCM preparations.

Disease-Modifying Treatments and Their Future in Alzheimer's Disease Management

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory impairment, a loss of cholinergic neurons, and cognitive decline that insidiously progresses to dementia. The pathoetiology of AD is complex, as genetic predisposition, age, inflammation, oxidative stress, and dysregulated proteostasis all contribute to its development and progression. The histological hallmarks of AD are the formation and accumulation of amyloid-β plaques and interfibrillar tau tangles within the central nervous system. These histological hallmarks trigger neuroinflammation and disrupt the physiological structure and functioning of neurons, leading to cognitive dysfunction. Most treatments currently available for AD focus only on symptomatic relief. Disease-modifying treatments (DMTs) that target the biology of the disease in hopes of slowing or reversing disease progression are desperately needed. This narrative review investigates novel DMTs and their therapeutic targets that are either in phase three of development or have been recently approved by the U.S. Food and Drug Administration (FDA). The target areas of some of these novel DMTs consist of combatting amyloid or tau accumulation, oxidative stress, neuroinflammation, and dysregulated proteostasis, metabolism, or circadian rhythm. Neuroprotection and neuroplasticity promotion were also key target areas. DMT therapeutic target diversity may permit improved therapeutic responses in certain subpopulations of AD, particularly if the therapeutic target of the DMT being administered aligns with the subpopulation's most prominent pathological findings. Clinicians should be cognizant of how these novel drugs differ in therapeutic targets, as this knowledge may potentially enhance the level of care they can provide to AD patients in the future.

Progress of Ginsenoside Rb1 in neurological disorders

Ginseng is frequently used in traditional Chinese medicine to treat neurological disorders. The primary active component of ginseng is ginsenoside, which has been classified into more than 110 types based on their chemical structures. Ginsenoside Rb1 (GsRb1)-a protopanaxadiol saponin and a typical ginseng component-exhibits anti-inflammatory, anti-oxidant, anti-apoptotic, and anti-autophagy properties in the nervous system. Neurological disorders remain a leading cause of death and disability globally. GsRb1 effectively treats neurological disorders. To contribute novel insights to the understanding and treatment of neurological disorders, we present a comprehensive review of the pharmacokinetics, actions, mechanisms, and research development of GsRb1 in neurological disorders.