Acupuncture-related treatments improve cognitive and physical functions in Alzheimer's disease: A systematic review and meta-analysis of randomized controlled trials

Acupuncture and moxibustion therapy for cognitive impairment: the microbiome-gut-brain axis and its role

Cognitive impairment poses a significant burden on individuals, families, and society worldwide. Despite the lack of effective treatment strategies, emerging evidence suggests that the microbiome-gut-brain (MGB) axis may play a critical role in the pathogenesis of cognitive impairment. While targeted treatment is not yet comprehensive, recently, acupuncture and moxibustion therapy has participated increasingly in the treatment of degenerative diseases and has achieved a certain therapeutic effect. In this review, the possible mechanisms by which acupuncture and moxibustion therapy may improve cognitive impairment through the MGB axis are reviewed, including regulating gut microbial homeostasis, improving intestinal inflammation mediated by the neuroendocrine-immune system, and enhancing intestinal barrier function. We also discuss common acupoints and corresponding mechanism analysis to provide insights into further exploration of mechanisms that target the MGB axis and thereby intervene in cognitive impairment.

An overview of systematic reviews of acupuncture for neurodegenerative disease

BACKGROUND

Acupuncture has been widely used in the treatment of neurodegenerative diseases and a large number of systematic reviews (SRs) have been published, but the results are controversial. Therefore, it is necessary to comprehensively summarize and objectively evaluate the clinical evidence of acupuncture for neurodegenerative diseases.

OBJECTIVE

To evaluate the SRs that assess the efficacy and safety of acupuncture for neurodegenerative diseases. This overview is intended to provide evidence for clinical decision making by healthcare providers and policymakers and to provide evidence for clinical decision making by healthcare providers and policymakers and to provide recommendations for researchers to conduct high quality SRs and clinical studies.

METHODS

We searched four Chinese databases (SinoMed, CNKI, Wanfang and VIP) and four international databases (Cochrane Library, Embase, PubMed and Web of Science) for SRs of acupuncture for neurodegenerative diseases. The search period ran from the beginning of the database to March 5, 2023. Literature screening and data extraction were performed independently by two individuals. Methodological quality, risk of bias and associated evidence levels were assessed for all SRs using AMSTER 2, ROBIS and GRADE tools. In addition, the RCT overlap between SRs was calculated by corrected coverage area (CCA). We also conducted quantitative synthesis or descriptive analysis of the relevant data.

RESULTS

Finally, we identified 53 SRs (three were qualitative descriptions and fifty were meta-analyses). Under AMSTAR 2, only one SR was rated as moderate quality, six SRs as low quality and 46 SRs as very low quality. According to ROBIS, 33 SRs were rated as a high risk of bias and 20 as a low risk of bias. Cognitive functions in neurodegenerative diseases, activities of daily living and the motor and non-motor outcomes associated with PD were included to summary description. The pooled results show that acupuncture combined with conventional treatment may have an overall advantage over conventional treatment, but the quality of evidence is low. Specific adverse reactions/events were reported in 20 SRs. Common needle-related adverse events included pain, dizziness, bleeding, or subcutaneous hematoma. No severe adverse events were reported in any SRs.

CONCLUSION

Evidence suggests that acupuncture is generally effective and relatively safe for cognitive function and activities of daily living in neurodegenerative diseases. In addition, acupuncture may have some benefits in improving motor and non-motor symptoms in patients with PD. However, high-quality RCTs and SRs are still needed to further clarify the efficacy and safety of acupuncture in treating neurodegenerative diseases.

The past and present of therapeutic strategy for Alzheimer's diseases: potential for stem cell therapy

Alzheimer's disease (AD), a progressive neurodegenerative disease characterized by cognitive dysfunction and neuropsychiatric symptoms, is the most prevalent form of dementia among the elderly. Amyloid aggregation, tau hyperphosphorylation, and neural cell loss are the main pathological features. Various hypotheses have been proposed to explain the development of AD. Some therapeutic agents have shown clinical benefits in patients with AD; however, many of these agents have failed. The degree of neural cell loss is associated with the severity of AD. Adult neurogenesis, which governs cognitive and emotional behaviors, occurs in the hippocampus, and some research groups have reported that neural cell transplantation into the hippocampus improves cognitive dysfunction in AD model mice. Based on these clinical findings, stem cell therapy for patients with AD has recently attracted attention. This review provides past and present therapeutic strategies for the management and treatment of AD.

Integrating Acupuncture into a Dialysis Center

A growing interest in integrating traditional Chinese medicine (TCM) and conventional medicine (CM) to create a more comprehensive approach to healthcare has been verified. Scientific evidence supports acupuncture as an integrative treatment for specific health conditions. The aim of this study was to assess the acceptance and feasibility by patients and healthcare professionals of integrating acupuncture in a dialysis center. Individuals undergoing hemodialysis (HD) who participated in a patient-assessor-blinded randomized controlled trial that evaluated the effect of acupuncture on functional capacity and quality of life were included. Acceptance was measured by adherence (percentage of patients who completed treatments and dropouts) and patients' and healthcare professionals' opinions toward acupuncture (pre- and pro-intervention questionnaires). Feasibility was measured by safety (number of reported adverse events) and effectiveness (changes in functional capacity, peripheral muscle strength, and health-related quality of life scores after treatment). Forty-eight patients were included, and forty-five (93.8%) were analyzed. No adverse events were reported. All patients completed the treatment, and only three patients (6.2%) were lost to the 12-week post-treatment follow-up. The attitudes of patients and health professionals were favorable to acupuncture, namely in relation to its use, degree of discomfort, recommendation to others, and interference with routine care and clinical setting. Integrating acupuncture into a dialysis center seems viable and well-accepted by patients with kidney failure on maintenance HD, doctors and nurses.

Research progress on acupuncture treatment in central nervous system diseases based on NLRP3 inflammasome in animal models

Central nervous system (CNS) disorders exhibit complex neurophysiological and pathological mechanisms, which seriously affect the quality of life in patients. Acupuncture, widely accepted as complementary and alternative medicine, has been proven to exert significant therapeutic effects on CNS diseases. As a part of the innate immune system, NLRP3 inflammasome contributes to the pathogenesis of CNS diseases via regulating neuroinflammation. To further explore the mechanisms of acupuncture regulating NLRP3 inflammasome in CNS diseases, our study focused on the effects of acupuncture on neuroinflammation and the NLRP3 inflammasome in vascular dementia, Alzheimer's disease, stroke, depression, and spinal cord injury. This study confirmed that the activation of NLRP3 inflammasome promotes the development of CNS diseases, and inhibiting the activation of NLRP3 inflammasome is a potential key target for the treatment of CNS diseases. In addition, it is concluded that acupuncture alleviates neuroinflammation by inhibiting the activation of the NLRP3 inflammasome pathway, thereby improving the progression of CNS diseases, which provides a theoretical basis for acupuncture to attenuate neuroinflammation and improve CNS diseases.

Acupuncture Interventions for Alzheimer’s Disease and Vascular Cognitive Disorders: A Review of Mechanisms

Cognitive impairment (CI) related to Alzheimer's disease (AD) and vascular cognitive disorders (VCDs) has become a key problem worldwide. Importantly, CI is a neuropsychiatric abnormality mainly characterized by learning and memory impairments. The hippocampus is an important brain region controlling learning and memory. Recent studies have highlighted the effects of acupuncture on memory deficits in AD and VCDs. By reviewing the literature published on this topic in the past five years, the present study intends to summarize the effects of acupuncture on memory impairment in AD and VCDs. Focusing on hippocampal synaptic plasticity, we reviewed the mechanisms underlying the effects of acupuncture on memory impairments through regulation of synaptic proteins, AD characteristic proteins, intestinal microbiota, neuroinflammation, microRNA expression, orexin system, energy metabolism, etc., suggesting that hippocampal synaptic plasticity may be the common as well as the core link underlying the above mechanisms. We also discussed the potential strategies to improve the effect of acupuncture. Additionally, the effects of acupuncture on synaptic plasticity through the regulation of vascular–glia–neuron unit were further discussed.

Effects of Electroacupuncture on the Correlation between Serum and Central Immunity in AD Model Animals

Objective

The goal was to investigate the connection between neuroinflammation in the brain and serum inflammatory markers as Alzheimer's disease progressed. We also sought to determine whether electroacupuncture had an effect on inflammatory markers found in blood and other brain regions.

Methods

As an animal model for AD, we used senescence-accelerated mouse prone 8 (SAMP8) mice. To examine the effects and probable mechanism of electroacupuncture, we used HE staining, immunofluorescence staining, western blotting, and enzyme-linked immunosorbent assay.

Results

Electroacupuncture therapy protected neurons, significantly downregulated the Iba-1 level in the hippocampus (p value was 0.003), frontal lobe cortex (p value was 0.042), and temporal lobe cortex (p value was 0.013) of the AD animal model, all of which had significantly lower levels of IL-6 (p value was 0.001), IL-1β (p value was 0.001), and TNF-α (p value was 0.001) in their serum.

Conclusion

The amounts of IL-6, IL-1β, and TNF-α detected in the serum were strongly linked to the levels discovered in the hippocampus and the frontal lobes of the brain, respectively. A better understanding of the electroacupuncture process as well as the course of Alzheimer's disease and the therapeutic benefits of electroacupuncture may be gained by using biomarkers such as serum inflammatory marker biomarkers.

Modulation of entorhinal cortex–hippocampus connectivity and recognition memory following electroacupuncture on 3×Tg-AD model: Evidence from multimodal MRI and electrophysiological recordings

Memory loss and aberrant neuronal network activity are part of the earliest hallmarks of Alzheimer’s disease (AD). Electroacupuncture (EA) has been recognized as a cognitive stimulation for its effects on memory disorder, but whether different brain regions or neural circuits contribute to memory recovery in AD remains unknown. Here, we found that memory deficit was ameliorated in 3×Tg-AD mice with EA-treatment, as shown by the increased number of exploring and time spent in the novel object. In addition, reduced locomotor activity was observed in 3×Tg-AD mice, but no significant alteration was seen in the EA-treated mice. Based on the functional magnetic resonance imaging, the regional spontaneous activity alterations of 3×Tg-AD were mainly concentrated in the accumbens nucleus, auditory cortex, caudate putamen, entorhinal cortex (EC), hippocampus, insular cortex, subiculum, temporal cortex, visual cortex, and so on. While EA-treatment prevented the chaos of brain activity in parts of the above regions, such as the auditory cortex, EC, hippocampus, subiculum, and temporal cortex. And then we used the whole-cell voltage-clamp recording to reveal the neurotransmission in the hippocampus, and found that EA-treatment reversed the synaptic spontaneous release. Since the hippocampus receives most of the projections of the EC, the hippocampus-EC circuit is one of the neural circuits related to memory impairment. We further applied diffusion tensor imaging (DTI) tracking and functional connectivity, and found that hypo-connected between the hippocampus and EC with EA-treatment. These data indicate that the hippocampus–EC connectivity is responsible for the recognition memory deficit in the AD mice with EA-treatment, and provide novel insight into potential therapies for memory loss in AD.