Acupuncture ameliorates cognitive impairment and hippocampus neuronal loss in experimental vascular dementia through Nrf2-mediated antioxidant response

Cognitive and Hippocampal Changes in Older Adults With Subjective Cognitive Decline After Acupuncture Intervention

OBJECTIVE

Converging evidence indicates that subjective cognitive decline (SCD) could be an early indicator of dementia. The hippocampus is the earliest affected region during the progression of cognitive impairment. However, little is known about whether and how acupuncture change the hippocampal structure and function of SCD individuals.

METHODS

Here, we used multi-modal MRI to reveal the mechanism of acupuncture in treating SCD. Seventy-two older participants were randomized into acupuncture or sham acupuncture group and treated for 12 weeks.

RESULTS

At the end of the intervention, compared to sham acupuncture, participants with acupuncture treatment showed improvement in composite Z score from multi-domain neuropsychological tests, as well as increased hippocampal volume and functional connectivity. Moreover, the greater white matter integrity of the fornix, which is the major output tract of the hippocampus, was shown in the acupuncture group.

CONCLUSION

These findings suggest that acupuncture may improve the cognitive function of SCD individuals, and increase hippocampal volume on the regional level and enhance the structural and functional connectivity of hippocampus on the connective level.

Effectiveness and safety of Governor vessel acupuncture therapy for post-stroke cognitive impairment: A meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study was to evaluate the effectiveness of Governor vessel acupuncture (GV Ac) in treating post-stroke cognitive impairment (PSCI).

METHODS

There was a total of seven databases examined. Four English databases (Cochrane Library, PubMed, Embase, and Medline) and three Chinese databases (Chinese National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Databases (VIP), and Wan Fang Database) contain all randomized controlled trials (RCTs) comparing Governor vessel acupuncture to other treatments or none acupuncture for PSCI. The exact dates for the search period are from January 1, 2000, to January 1, 2023.Two researchers independently reviewed the literature, gathered RCT data, and performed statistical analysis. All data were analyzed using Review Manager software (Rev Man) 5.3.

RESULTS

This meta-analysis includes a total of 39 trials with 2044 patients. There were 1022 participants in each of the test and control groups. Following 12-120 days of acupuncture treatment, a meta-analysis revealed that the treatment groups (GV Ac combined with conventional treatment groups) significantly increased their scores on the Curative ratio (OR = 3.00, 95 %CI = 2.37-3.79, P = 0.98, I² = 0 %), Montreal Cognitive Assessment (MoCA)(MD = 1.82, 95 %CI = 1.60-2.03, P = 0.11, I² = 25 %), Mini-Mental State Examination (MMSE)(MD = 2.18, 95 %CI = 1.64-2.72, P<0.005, I² = 92 %), and Activity of Daily Living (ADL)(MD = 5.99, 95 %CI = 5.33-6.64, P = 0.19, I² = 26 %).

CONCLUSION

The results suggested that acupuncture on points of the Governor vessel enhanced cognitive function in stroke survivors.

Electroacupuncture improves cognitive function in APP/PS1 mice by inhibiting oxidative stress related hippocampal neuronal ferroptosis

BACKGROUND

Electroacupuncture, recognized as a crucial non-pharmacological therapeutic approach, has demonstrated notable efficacy in enhancing cognitive function among Alzheimer's disease (AD) patients. This study aimed to investigate the neuroprotective properties of electroacupuncture in APP/PS1 mice with AD.

METHODS

A total of thirty APP/PS1 mice were randomly assigned to three groups: the Alzheimer's disease group (AD), the electroacupuncture treatment group (EA), and the ferroptosis inhibitor deferasirox treatment group (DFX). Additionally, ten C57BL/6 mice were included as a control group (Control). In the EA group, mice underwent flat needling at Baihui and Yintang, as well as point needling at Renzhong, once daily for 15 min each time. In the DFX group, mice received intraperitoneal injections of deferasirox at a dosage of 100 mg/kg/day. Following the 28-day treatment period, behavioral evaluation, morphological observation of neurons, and detection of neuronal ferroptosis were conducted.

RESULTS

The electroacupuncture treatment demonstrated a significant improvement in spatial learning, memory ability, and neuronal damage in mice with AD. Analysis of neuronal ferroptosis markers indicated that electroacupuncture interventions reduced the elevated levels of malondialdehyde, iron, and ptgs2 expression, while also increasing superoxide dismutase activity, Ferroportin 1 and glutathione peroxidase 4 expression. Moreover, the regulatory impact of electroacupuncture on ferroptosis may be attributed to its ability to enhance the expression and nuclear translocation of Nrf2.

CONCLUSIONS

This study suggested that electroacupuncture could inhibit the neuronal ferroptosis by activating the antioxidant function in neurons through p62/Keap1/Nrf2 signal pathway, thereby improve the cognitive function of AD mice by the neuronal protection effect.

Mobilizing endogenous neuroprotection: the mechanism of the protective effect of acupuncture on the brain after stroke

Given its high morbidity, disability, and mortality rates, ischemic stroke (IS) is a severe disease posing a substantial public health threat. Although early thrombolytic therapy is effective in IS treatment, the limited time frame for its administration presents a formidable challenge. Upon occurrence, IS triggers an ischemic cascade response, inducing the brain to generate endogenous protective mechanisms against excitotoxicity and inflammation, among other pathological processes. Stroke patients often experience limited recovery stages. As a result, activating their innate self-protective capacity [endogenous brain protection (EBP)] is essential for neurological function recovery. Acupuncture has exhibited clinical efficacy in cerebral ischemic stroke (CIS) treatment by promoting the human body's self-preservation and "Zheng Qi" (a term in traditional Chinese medicine (TCM) describing positive capabilities such as self-immunity, self-recovery, and disease prevention). According to research, acupuncture can modulate astrocyte activity, decrease oxidative stress (OS), and protect neurons by inhibiting excitotoxicity, inflammation, and apoptosis via activating endogenous protective mechanisms within the brain. Furthermore, acupuncture was found to modulate microglia transformation, thereby reducing inflammation and autoimmune responses, as well as promoting blood flow restoration by regulating the vasculature or the blood-brain barrier (BBB). However, the precise mechanism underlying these processes remains unclear. Consequently, this review aims to shed light on the potential acupuncture-induced endogenous neuroprotective mechanisms by critically examining experimental evidence on the preventive and therapeutic effects exerted by acupuncture on CIS. This review offers a theoretical foundation for acupuncture-based stroke treatment.

Geraniol attenuates oxidative stress and neuroinflammation-mediated cognitive impairment in D galactose-induced mouse aging model

D-galactose (D-gal) administration was proven to induce cognitive impairment and aging in rodents' models. Geraniol (GNL) belongs to the acyclic isoprenoid monoterpenes. GNL reduces inflammation by changing important signaling pathways and cytokines, and thus it is plausible to be used as a medicine for treating disorders linked to inflammation. Herein, we examined the therapeutic effects of GNL on D-gal-induced oxidative stress and neuroinflammation-mediated memory loss in mice. The study was conducted using six groups of mice (6 mice per group). The first group received normal saline, then D-gal (150 mg/wt) dissolved in normal saline solution (0.9%, w/v) was given orally for 9 weeks to the second group. In the III group, from the second week until the 10th week, mice were treated orally (without anesthesia) with D-gal (150 mg/kg body wt) and GNL weekly twice (40 mg/kg body wt) four hours later. Mice in Group IV were treated with GNL from the second week up until the end of the experiment. For comparison of young versus elderly mice, 4 month old (Group V) and 16-month-old (Group VI) control mice were used. We evaluated the changes in antioxidant levels, PI3K/Akt levels, and Nrf2 levels. We also examined how D-gal and GNL treated pathological aging changes. Administration of GNL induced a significant increase in spatial learning and memory with spontaneously altered behavior. Enhancing anti-oxidant and anti-inflammatory effects and activating PI3K/Akt were the mechanisms that mediated this effect. Further, GNL treatment upregulated Nrf2 and HO-1 to reduce oxidative stress and apoptosis. This was confirmed using 99mTc-HMPAO brain flow gamma bioassays. Thus, our data suggested GNL as a promising agent for treating neuroinflammation-induced cognitive impairment.

The effect of acupuncture on oxidative stress in animal models of vascular dementia: a systematic review and meta-analysis

BACKGROUND

Growing evidence showed that acupuncture may improve cognitive function by reducing oxidative stress, key to the pathogenesis in vascular dementia (VaD), but this is yet to be systematically analysed. This study aimed to summarize and evaluate the effect of acupuncture on oxidative stress in animal models of VaD.

METHOD

Eight databases including PubMed, Embase, Web of Science, Cochrane library, CNKI, Wan Fang, CBM, and VIP were searched since their establishment until April 2023, for studies that reported the effect of acupuncture on oxidative stress in VaD animal models. Relevant literature was screened, and information was extracted by two reviewers. The primary outcomes were the levels of oxidative stress indicators. The methodological quality was assessed via the SYRCLE Risk of Bias Tool. Statistical analyses were performed using the RevMan and Stata software.

RESULTS

In total, 22 studies with 747 animals were included. The methodology of most studies had flaws or uncertainties. The meta-analysis indicated that, overall, acupuncture significantly reduced the expression of pro-oxidants including reactive oxygen species (standardized mean differences [SMDs] = -4.29, 95% confidence interval [CI]: -6.26, -2.31), malondialdehyde (SMD = -2.27, 95% CI: -3.07, -1.47), nitric oxide (SMD = -0.85, 95% CI: -1.50, -0.20), and nitric oxide synthase (SMD = -1.01, 95% CI: -1.69, -0.34) and enhanced the levels of anti-oxidants including super oxide dismutase (SMD = 2.80, 95% CI: 1.98, 3.61), glutathione peroxidase (SMD = 1.32, 95% CI: -0.11, 2.76), and catalase (SMD = 1.31, 95% CI: 0.05, 2.58) in VaD animal models. In subgroup analyses, acupuncture showed significant effects on most variables. Only partial modelling methods and treatment duration could interpret the heterogeneity of some outcomes.

CONCLUSION

Acupuncture may inhibit oxidative stress to improve cognitive deficits in animal models of VaD. Nevertheless, the methodological quality is unsatisfactory. More high-quality research with a rigorous design and further experimental researches and clinical trials are needed to confirm these findings.

SYSTEMATIC REVIEW REGISTRATION

This study was registered in PROSPERO (CRD42023411720).

Prevotella histicola Transplantation Ameliorates Cognitive Impairment and Decreases Oxidative Stress in Vascular Dementia Rats

Vascular dementia is a type of dementia from brain damage caused by cerebrovascular lesions and vascular risk factors. Prevotella histicola is a species of Prevotella, belonging to the category of obligate anaerobe. The purpose of our work was to study the protection of Prevotella histicola on cognitive function in rats subjected to vascular dementia (VaD) and investigate underlying molecular mechanisms. The rats were randomly divided into three groups: control group, 2VO group and 2VO + Prevotella histicola group. The VaD rats (the 2VO group and 2VO + Prevotella histicola group) were generated by bilateral common carotid artery occlusion (2VO). Rats in the 2VO+ Prevotella histicola group were administered with Prevotella histicola twice daily. In comparison with the rats in the 2VO group, rats in the 2VO + Prevotella histicola group presented an enhanced cognitive ability, increased synapse-associated protein expression, a downregulation of proinflammatory factors and an upregulation of neurotrophic factors. The relevant mechanism of the protective effect of Prevotella histicola may be associated with the inhibition of glial cell-associated inflammation by regulating phosphorylation of CaMKII. In conclusion, Prevotella histicola attenuates neurological impairments via regulating synapse-associated protein expression and the liberation of inflammatory elements in vascular dementia rats. The findings above might benefit the development of Prevotella histicola transplantation as a promising treatment of VaD.

Can acupuncture reverse oxidative stress and neuroinflammatory damage in animal models of vascular dementia?: A preclinical systematic review and meta-analysis

BACKGROUND

Vascular dementia is a cognitive dysfunction syndrome caused by cerebral vascular factors such as ischemic stroke and hemorrhagic stroke. The effect of acupuncture on vascular dementia models is ambiguous, and there is controversy about whether acupuncture has a placebo effect. Oxidative stress and inflammation are the most essential mechanisms in preclinical studies of vascular dementia. However, there is no meta-analysis on the mechanism of vascular dementia in animal models. It is necessary to explore the efficacy of acupuncture through Meta-analysis of preclinical studies.

METHODS

Three major databases, PubMed, Embase and Web of Science (including medline), were searched in English until December 2022.The quality of the including literature was assessed using SYRCLE's risk of bias tool. Review Manager 5.3 was used to statistically summarize the included studies and the statistical effect values were expressed by SMD. The outcomes included: behavioral tests (escape latency, number of crossings), pathological sections (Nissl and TUNEL staining), oxidative stress markers (ROS, MDA, SOD, GSH-PX) and neuroinflammatory factors (TNF-α, IL-1β, IL-6).

RESULTS

A total of 31 articles were included in this meta-analysis. The results showed that the escape latency, the contents of ROS, MDA, IL-1β, and IL-6 were decreased, and the contents of SOD and Nissl-positive neurons were increased in the acupuncture group as compared with the non-group (P < .05). Compared with the impaired group, the acupuncture group also had the above advantages (P < .05). In addition, the acupuncture group also increased the number of crossings and GSH-PX content, and decreased the expression of TUNEL-positive neurons and TNF-α (P < .05).

CONCLUSIONS

From behavioral tests to slices and pathological markers in animal models of vascular dementia, it can be proved that acupuncture is effective in targeting oxidative stress and neuroinflammatory damage, and acupuncture is not a placebo effect. Nevertheless, attention needs to be paid to the gap between animal experiments and clinical applications.

Neuroimaging studies of acupuncture on Alzheimer's disease: a systematic review

BACKGROUND

Acupuncture effectively improves cognitive function in Alzheimer's disease (AD). Many neuroimaging studies have found significant brain alterations after acupuncture treatment of AD, but the underlying central modulation mechanism is unclear.

OBJECTIVE

This review aims to provide neuroimaging evidence to understand the central mechanisms of acupuncture in patients with AD.

METHODS

Relevant neuroimaging studies about acupuncture for AD were retrieved from eight English and Chinese medicine databases (PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI, WF, VIP) and other resources from inception of databases until June 1, 2022, and their methodological quality was assessed using RoB 2.0 and ROBINS - I. Brain neuroimaging information was extracted to investigate the potential neural mechanism of acupuncture for AD. Descriptive statistics were used for data analysis.

RESULTS

Thirteen neuroimaging studies involving 275 participants were included in this review, and the overall methodological quality of included studies was moderate. The approaches applied included task-state functional magnetic resonance imaging (ts-fMRI; n = 9 studies) and rest-state functional magnetic resonance imaging (rs-fMRI; n = 4 studies). All studies focused on the instant effect of acupuncture on the brains of AD participants, including the cingulate gyrus, middle frontal gyrus, and cerebellum, indicating that acupuncture may regulate the default mode, central executive, and frontoparietal networks.

CONCLUSION

This study provides evidence of the neural mechanisms underlying the effect of acupuncture on AD involving cognitive- and motor-associated networks. However, this evidence is still in the preliminary investigation stage. Large-scale, well-designed, multimodal neuroimaging trials are still required to provide comprehensive insight into the central mechanism underlying the effect of acupuncture on AD. (Systematic review registration at PROSPERO, No. CRD42022331527).

The neuroprotective and neural circuit mechanisms of acupoint stimulation for cognitive impairment

Cognitive impairment is a prevalent neurological disorder that burdens families and the healthcare system. Current conventional therapies for cognitive impairment, such as cholinesterase inhibitors and N-methyl-d-aspartate receptor antagonists, are unable to completely stop or reverse the progression of the disease. Also, these medicines may cause serious problems with the digestive system, cardiovascular system, and sleep. Clinically, stimulation of acupoints has the potential to ameliorate the common symptoms of a variety of cognitive disorders, such as memory deficit, language dysfunction, executive dysfunction, reduced ability to live independently, etc. There are common acupoint stimulation mechanisms for treating various types of cognitive impairment, but few systematic analyses of the underlying mechanisms in this domain have been performed. This study comprehensively reviewed the basic research from the last 20 years and found that acupoint stimulation can effectively improve the spatial learning and memory of animals. The common mechanism may be that acupoint stimulation protects hippocampal neurons by preventing apoptosis and scavenging toxic proteins. Additionally, acupoint stimulation has antioxidant and anti-inflammatory effects, promoting neural regeneration, regulating synaptic plasticity, and normalizing neural circuits by restoring brain functional activity and connectivity. Acupoint stimulation also inhibits the production of amyloid β-peptide and the phosphorylation of Tau protein, suggesting that it may protect neurons by promoting correct protein folding and regulating the degradation of toxic proteins via the autophagy-lysosomal pathway. However, the benefits of acupoint stimulation still need to be further explored in more high-quality studies in the future.

Pharmaceutical and pharmacological studies of Shen Ma Yi Zhi granule for prevention of vascular dementia: A review

Background: With dementia significantly increasing hospitalization and disability rates, worldwide aging of the population presents major challenges to public health. The majority of cases of cognitive dysfunction among the elderly, however, are characterized by an identifiable, preventable and treatable vascular component. As such, increased study of preventative methods in the context of dementia is warranted. Traditional Chinese medicine compounds have been reported to be neuroprotective and improve cognitive function via a variety of mechanisms. Shen Ma Yi Zhi granule (SMYZG) is one such collection of compounds that has been proven clinically effective. Pharmacological mechanisms of action, pharmacokinetics and clinical applications of SMYZG have been previously studied using a variety of vascular dementia animal models. SMYZG activates and regulates four main signaling pathways relevant to vascular dementia including the AMPK/PPARα/PGC-1α/UCP2, Nrf2/HO-1, HIF-1/VEGF/Notch, and VEGF/Flk-1/p8 MAPK pathways. Furthermore, SMYZG influences anti-inflammatory and anti-oxidant stress responses, reverses demyelination of brain white matter and vascular endothelium, regulates pericyte function and normalizes mitochondrial metabolism. Neuroprotective effects of SMYZG, as well as those promoting regeneration of vascular endothelium, have also been reported in studies of rat models of vascular dementia. Future research concerning SMYG is warranted for development of vascular dementia preventative management strategies.

Bibliometric analysis: Research trends of acupuncture treatment to cognitive impairment in recent 15 years

Objectives

Acupuncture therapy has been used for cognitive impairment-related diseases, however, there are still few studies on the overall trend of acupuncture therapy on cognitive impairment based on bibliometric analysis. The purpose of this study was to explore the research trend of the impact of acupuncture on cognitive impairment in the past 15 years, analyze the research trends and hotspots, and provide new ideas and theoretical basis for future research directions.

Methods

From the Web of Science Core Collection (WoSCC), the relevant literature on the treatment of cognitive impairment with acupuncture from 2007 to 2022 was retrieved. Then, based on the CiteSpace and VOSviewer software of the Java platform, the cooperation between countries and institutions in this field, the co-citation of journals and documents, and the cooperation between authors and authors, etc. were analyzed. In addition, the co-occurrence and burst analysis of keywords are also carried out, and a visual knowledge map is drawn.

Results

As of August 08, 2022, a total of 394 records related to the treatment of cognitive impairment with acupuncture were identified. The analysis results show: The number and rate of annual publications have steadily increased, with some fluctuations from year to year. The countries that contribute the most to this field are China and the USA. Among them, Beijing University of Chinese Medicine and Capital Medical University are tied for first place in terms of the number of published papers. Tao Jing is the most prolific author and the number one cited author.

Conclusions

The number of publications on acupuncture for cognitive impairment is expected to increase rapidly in future research, suggesting a bright future for the field. Future research hotspots will focus on pain, injury, protocol, diagnosis, guidelines, etc. It is also necessary to strengthen cross-regional and cross-country cooperation among various academic groups.

Bibliometric review of 1992–2022 publications on acupuncture for cognitive impairment

Objective

To explore the development context, research hotspots, and frontiers of acupuncture therapy for cognitive impairment (CI) from 1992 to 2022 by visualization analysis.

Methods

Articles about acupuncture therapy for cognitive impairment were retrieved from the Web of Science Core Collection (WoSCC) until 1 March 2022. Basic information was collected by Excel 2007, and VOSviewer 1.6.17 was used to analyze the co-occurrence of countries, institutes, and authors. Co-citation maps of authors and references were analyzed by CiteSpace V.5.8.R3. In addition, CiteSpace was used to analyze keyword clusters and forecast research frontiers.

Results

A total of 279 articles were retrieved, including articles from 19 countries, 334 research institutes, and 101 academic journals. The most published country and institutes were the People's Republic of China (217) and the Fujian University of Traditional Chinese Medicine (40). Ronald C Petersen owned the highest co-citations (56). Keywords and co-cited references cluster showed the main research directions in this area, including “ischemic stroke,” “cerebral ischemia/reperfusion,” “mild cognitive impairment,” “Alzheimer's disease,” “vascular dementia,” “vascular cognitive impairment with no dementia,” “multi-infarct dementia,” “synaptic injury,” “functional MRI,” “glucose metabolism,” “NMDA,” “nuclear factor-kappa b pathway,” “neurotrophic factor,” “matrix metalloproteinase-2 (MMP-2),” “tumor necrosis factor-alpha,” “Bax,” “Caspase-3,” and “Noxa”. Trending keywords may indicate frontier topics, such as “randomized controlled trial,” “rat model,” and “meta-analysis.”

Conclusion

This research provides valuable information for the study of acupuncture. Diseases focus on mild cognitive impairment (MCI), Alzheimer's disease (AD), and vascular dementia (VaD). Tauopathies with hyperphosphorylation of Tau protein as the main lesions also need to be paid attention to. The development of functional magnetic resonance imaging (fMRI) will better explain the therapeutic effect of acupuncture treatment. The effect of acupuncture on a single point is more convincing, and acupuncture on Baihui (GV20) may be needed in the future. Finally, the implementation of high-quality multicenter randomized controlled trials (RCTs) requires increased collaboration among experts from multiple fields and countries.

Dexmedetomidine suppresses the isoflurane-induced neurological damage by upregulating Heme Oxygenase-1 via activation of the mitogen-activated protein kinase kinase 1/extracellular regulated protein kinases 1/nuclear factor erythroid 2-related factor 2 axis in aged rats

Dexmedetomidine (DEX) displays a neuroprotective role in aged rats with isoflurane (ISO)-induced cognitive impairment through antioxidant, and anti-inflammatory, and anti-apoptotic effects. Therefore, the present study was performed to define the molecular mechanism of DEX on ISO-induced neurological impairment in aged rats in relation to the MEK1/ERK1/Nrf2/HO-1 axis. The study enrolled elderly patients undergoing ISO anesthesia. Patient cognitive function following treatment with DEX was evaluated using mini-mental state examination (MMSE). The results revealed that DEX supplementation of anesthesia contributed to higher MMSE scores in patients one week post treatment. Rat model of neurological impairment was also induced in 18-month-age Wistar rats by ISO, followed by DEX treatment. Based on the results of Morris water maze experiment, ELISA, and TUNEL and hematoxylin-eosin staining, in vivo experiments confirmed that DEX could reduce the oxidative stress and neurological damage induced by ISO in rats. DEX activated the nuclear factor erythroid 2-related factor (Nrf2)/Heme Oxygenase 1 (HO-1) pathway. DEX upregulated the expression of Nrf2 and HO-1 by activating the MEK1/ERK1 pathway, whereby attenuating the ISO-caused oxidative stress and neurological damage in rats. Collectively, DEX suppresses the ISO-induced neurological impairment in the aged rats by promoting HO-1 through activation of the MEK1/ERK1/Nrf2 axis.

Efficacy of acupuncture in animal models of vascular dementia: A systematic review and network meta-analysis

Background and purpose

Acupuncture is widely used in clinical practice for the treatment of vascular diseases. However, the protocol, efficacy, and mechanism of acupuncture in animal models of vascular dementia are still controversial. Based on the above problems, we initiated this comprehensive study.

Methods

To analyze the literatures included in this study, 4 databases were searched and the SYRCLE's Risk of bias tool was employed. To perform the subgroup analysis of different acupuncture methods and the Review Manager 5.3 was applied. Meanwhile, the pairwise and network meta-analysis were conducted using Addis 1.16.8. The outcomes included escape latency, number of crossings, time spent in the target quadrant, and swimming speed.

Results

Forty-two studies with a total of 1,486 animals were included in this meta-analysis. According to the results from subgroup analysis, GV20 + ST36 (Baihui + bilateral Zusanli) combined with 14-day manual acupuncture can obtain best improvement of the rats cognitive function among all acupuncture regimens (MD: -23.41; 95%CI: -26.66, -20.15; I2 = 0%; P < 0.001). The heterogeneity of other acupuncture treatments was significantly higher than that of GV20 + ST36, because the treatment courses were not uniform. Pair-wise and network comparisons are highly consistent. The major results of the network meta-analysis were as follows, In comparison to the impaired group, the acupuncture group showed significantly reduced escape latency (MD: -25.87; 95%CI: -30.75, -21.12), increased number of original platform crossings (MD: 2.63; 95%CI: 1.94, 3.34) and time spent in the target quadrant (MD: 7.88; 95%CI: 4.25, 11.44). The overall results of the network meta-analysis are as follows: the normal and sham-operated groups performed the best, followed by medicine and acupuncture, while no effect was found in the impaired group treated with non-acupoint and palliative.

Conclusions

Acupuncture significantly improves cognitive function in rats with vascular dementia. Compared to other acupuncture plans, (GV20 + ST36, MA) and 14 -day manual acupuncture can be used to obtain better results. The main mechanism of acupuncture in the treatment of vascular dementia is reduced oxidative stress, neuronal inflammation, and apoptosis, as well as the increased synaptic plasticity and neurotransmitters.

Systematic review registration

https://inplasy.com/inplasy-2021-11-0036/, identifier: INPLASY2021110036.

A Study on the Pathogenesis of Vascular Cognitive Impairment and Dementia: The Chronic Cerebral Hypoperfusion Hypothesis

The pathogenic mechanisms underlying vascular cognitive impairment and dementia (VCID) remain controversial due to the heterogeneity of vascular causes and complexity of disease neuropathology. However, one common feature shared among all these vascular causes is cerebral blood flow (CBF) dysregulation, and chronic cerebral hypoperfusion (CCH) is the universal consequence of CBF dysregulation, which subsequently results in an insufficient blood supply to the brain, ultimately contributing to VCID. The purpose of this comprehensive review is to emphasize the important contributions of CCH to VCID and illustrate the current findings about the mechanisms involved in CCH-induced VCID pathological changes. Specifically, evidence is mainly provided to support the molecular mechanisms, including Aβ accumulation, inflammation, oxidative stress, blood-brain barrier (BBB) disruption, trophic uncoupling and white matter lesions (WMLs). Notably, there are close interactions among these multiple mechanisms, and further research is necessary to elucidate the hitherto unsolved questions regarding these interactions. An enhanced understanding of the pathological features in preclinical models could provide a theoretical basis, ultimately achieving the shift from treatment to prevention.

Anti-depressant effects of acupuncture: The insights from NLRP3 mediated pyroptosis and inflammation

The NLRP3-mediated pyroptosis, which could affect inflammation response, plays a key role in the development of depression. Acupuncture has been shown to be an effective treatment for depression. In this study, we aimed to determine whether acupuncture could confer antidepressant activity via decreasing NLRP3-mediated pyroptosis by reducing inflammation. Here, depression model of rats was induced by chronic unpredictable mild stress (CUMS) for 4 weeks. Acupuncture group was subjected to acupuncture at the Shangxing (GV23) and Fengfu (GV16) acupoints for 20 min every other day (a total of 14 times). Fluoxetine group was administered with fluoxetine (2.1 mg/kg with the concentration of 0.21 mg/mL) by oral gavage (1 mL/100 g) once a day for 28 days. Rats' depression-like phenotypes were reflected with behavioral tests and biological detection methods. Results showed that acupuncture significantly improved the depression-like behavior of CUMS rat, suppressed the expressions of NLRP3, ASC, caspase-1, GSDMD, IL-1β, IL-18, HMGB1, IFN-γ, IL-6 and TNF-α in the serum and hippocampus, restored the %area of microglia, astrocytes and neuronal cells in the hippocampus. These indicate that acupuncture can prevent CUMS-induced depression-like behaviors by reducing NLRP3-mediated pyroptosis and inflammation.

Electroacupuncture Increases the Hippocampal Synaptic Transmission Efficiency and Long-Term Plasticity to Improve Vascular Cognitive Impairment

Studies have shown that electroacupuncture (EA) can effectively improve vascular cognitive impairment (VCI), but its mechanisms have not been clearly elucidated. This study is aimed at investigating the mechanisms underlying the effects of EA treatment on hippocampal synaptic transmission efficiency and plasticity in rats with VCI. Methods. Sprague–Dawley rats were subjected to VCI with bilateral common carotid occlusion (2VO). EA stimulation was applied to Baihui (GV20) and Shenting (GV24) acupoints for 30 min once a day, five times a week, for four weeks. Our study also included nonacupoint groups to confirm the specificity of EA therapy. The Morris water maze (MWM) was used to assess cognitive function. Electrophysiological techniques were used to detect the field characteristics of the hippocampal CA3–CA1 circuit in each group of rats, including input-output (I/O), paired-pulse facilitation ratios (PPR), field excitatory postsynaptic potential (fEPSP), and excitatory postsynaptic current (EPSC). The expression of synapse- and calcium-mediated signal transduction associated proteins was detected through western blotting. Results. The MWM behavioural results showed that EA significantly improved cognitive function in VCI model rats. EA increased the I/O curve of VCI model rats from 20 to 90 μA. No significant differences were observed in hippocampal PPR. The fEPSP of the hippocampal CA3–CA1 circuit was significantly increased after EA treatment compared with that after nonacupuncture treatment. We found that EA led to an increase in the EPSC amplitude and frequency, especially in the decay and rise times. In addition, the protein expression and phosphorylation levels of N-methyl-D-aspartate receptor 2B, α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptor 1, and Ca²⁺-calmodulin-dependent protein kinase II increased to varying degrees in the hippocampus of VCI model rats. Conclusion. EA at GV20 and GV24 acupoints increased the basic synaptic transmission efficiency and synaptic plasticity of the hippocampal CA3–CA1 circuit, thereby improving learning and memory ability in rats with VCI.

Acupuncture Effect Assessment in APP/PS1 Transgenic Mice: On Regulating Learning-Memory Abilities, Gut Microbiota, and Microbial Metabolites

Alzheimer's disease (AD) is a brain illness that affects learning and memory capacities over time. In recent investigations, acupuncture has been shown to be an effective alternative treatment for AD. We investigated the effect of acupuncture on learning and memory abilities using a water maze in APP/PS1 transgenic mice. The amounts of Aβ and tau protein in mice's hippocampal tissue were determined using Western blot. The levels of IL-1β, IL-10, LPS and TNF-α in mice's serum were measured using ELISA. The variations of gut microbiota in mice's feces were determined using the 16SrDNA technique, and the metabolites were examined using a untargeted metabolomics methodology. The results showed that acupuncture treatment improved mice's learning and memory abilities substantially. Acupuncture therapy regulated the Aβ and tau protein concentration as well as the levels of IL-10 and LPS. Acupuncture treatment influenced the mouse microbiota and metabolites and had been linked to six biochemical pathways. This study adds to our understanding of the effect of acupuncture on AD and opens the door to further research into the alterations of intestinal bacteria in the presence of AD.

Neuroprotective Effects of Rhynchophylline Against Aβ1-42-Induced Oxidative Stress, Neurodegeneration, and Memory Impairment Via Nrf2-ARE Activation

Extensive studies have shown that oxidative stress is a crucial pathogenic factor in Alzheimer's disease (AD). Nuclear factor E2-related factor 2 (Nrf2) is a master cytoprotective regulator against oxidative stress, and thus represents an attractive therapeutic target in AD. The goal of our study is to investigate the contribution of Nrf2 in Rhynchophylline (Rhy)-induced neuroprotection in AD. The data showed that intraperitoneal administration of Rhy (10 or 20 mg/kg) could ameliorate Aβ1-42-induced cognitive impairment, evidenced by performance improvement in memory tests. The result of Antioxidant response element (ARE)-luciferase activity assay indicated that Rhy treatment improved ARE promoter activity. The results of reactive oxygen species (ROS), malondialdehyde (MDA) and glutathione (GSH) assessment in the frontal cortex and hippocampus showed that Rhy treatment could attenuate Aβ1-42-induced oxidative stress to some extent, evidenced by reversion of these cytokines compared to Aβ1-42 + Veh group. Rhy treatment also restored expression of Nrf2 and its downstream protein heme oxygenase-1 (HO-1), NAD(P)H/quinone oxidoreductase 1 (NOQ1), and recombinant glutamate cysteine ligase, modifier subunit (GCLM) in the frontal cortex and hippocampus of Aβ1-42-treated mice. In addition, to investigate whether activation of Nrf2-mediated pathway is responsible for the neuroprotection of Rhy, Nrf2 siRNA was used in human neuroblastoma cells (SH-SY5Y). Interestingly, the results showed that the protective effects of Rhy, including anti-oxidative, anti-apoptosis and elevation of Nrf2 and its downstream proteins, were abolished in Nrf2 siRNA-transfected cells. These findings indicate that Rhynchophylline is protective against Aβ1-42-induced neurotoxicity via Nrf2-ARE activation, and suggest that Rhy may serve as a potential candidate and promising Nrf2 activator for management of AD.

Acupuncture Can Regulate the Peripheral Immune Cell Spectrum and Inflammatory Environment of the Vascular Dementia Rat, and Improve the Cognitive Dysfunction of the Rats

Objective

The aim of this study is to analyze the effects of acupuncture on peripheral immune function, inflammation, and cognitive impairment in vascular dementia (VD) rats.

Methods

In this study, 2-month-old healthy male Wistar rats (260-280 g) were assigned to the groups as follows: normal group (Gn, n = 10), sham-operated group (Gs, n = 10), and operated group (Go, n = 45). The Go group was established by permanent, bilateral common carotid artery occlusion (BCCAO). Two months after operation, the operated rats were screened by hidden platform trial and the rats with cognitive dysfunction were further randomly divided into impaired group (Gi), acupoint group (Ga), and non-acupoint group (Gna) with 10 rats in each group. The Ga group was given acupuncture treatment for 14 days with a rest for every 7 days. After treatment, the Morris water maze (MWM) test was performed to evaluate the spatial learning and memory abilities of rats. The lymphocyte subsets in peripheral blood and spleen of rats were measured by flow cytometry. The levels of cytokines [i.e., interleukin (IL)-1β, IL-2, IL-4, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (INF-γ)], chemokines (i.e., macrophage inflammatory protein-2 (MIP-2)), and other inflammatory mediators (i.e., cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS)) in peripheral blood and hippocampus were measured by enzyme linked immunosorbent assay (ELISA).

Results

Compared with the Gn group, the Gi rats presented long escape latencies to find the platform. After acupuncture treatment, the escape latencies of the Ga group were rescued markedly when compared with the Gi group (P < 0.05). The proportion of CD4 + T lymphocytes in both spleen and peripheral blood in the Ga group increased (P < 0.05) in comparison with the Gi group. There is an obvious reduction in IL-1β (P < 0.05), IL-2 (P < 0.05), TNF-α (P < 0.01), INF-γ (P < 0.01), MIP-2 (P < 0.05), and iNOS (P < 0.01), coming along with the increased levels of IL-4 and IL-10 (P < 0.01) in the Ga group when compared with the Gi group. In addition, the hippocampus proinflammatory factors IL-1β (P < 0.01), IL-2 (P < 0.01), TNF-α (P < 0.05), INF-γ (P < 0.05), MIP-2 (P < 0.05), iNOS (P < 0.01), and COX-2 decreased in the Ga group, whereas the anti-inflammatory factors IL-4 and IL-10 (P < 0.01) increased.

Conclusion

There are abnormal immune function and peripheral inflammation in VD rats. Acupuncture can regulate the peripheral immune function and inflammation of the VD rats and can improve the cognitive dysfunction of the rats.

Effects of Acupuncture on Oxidative Stress Amelioration via Nrf2/ARE-Related Pathways in Alzheimer and Parkinson Diseases

Oxidative stress is responsible for the pathogeneses of various diseases. Mitochondrial dysfunction, impaired DNA repair, and cellular damage followed by oxidative stress contribute to neurodegenerative diseases, such as Alzheimer disease (AD) and Parkinson disease (PD). Acupuncture is a traditional therapy that has been practiced for >3000 years in Asia. Many studies have demonstrated that acupuncture has notable antioxidative, anti-inflammatory, and antiapoptotic effects. However, the exact mechanism remains unclear. Nuclear factor erythroid 2-related factor (Nrf2) is crucial in regulating the redox equilibrium. Activated Nfr2 translocates into the nucleus, binds to the antioxidant response element (ARE), and initiates antioxidative enzyme transcription. In this review, we demonstrated the effects of acupuncture on oxidative stress amelioration in AD and PD animal models through Nrf2/ARE pathway activation and Nrf2/ARE-related pathway regulation. Thus, acupuncture could be a therapeutic option for AD and PD.

Effects of imperatorin on apoptosis and synaptic plasticity in vascular dementia rats

In view of the complicated pathophysiological process of vascular dementia (VD), drugs for the clinical treatment of VD mainly target related risk factors, while drugs with excellent efficacy in cognitive function are still relatively lacking. Imperatorin (IMP), an active constituent extracted from angelica dahuricae and notopterygium Notopterygii, which has anti-inflammatory, vasodilator, anticoagulant, block calcium channel, anticonvulsant, and anti oxygen free radical injury properties. Therefore,the present study examined its effects on VD rats and the underlying molecular mechanisms, in order to provide promising therapeutic methods. VD was established by modified ligation of perpetual two-vessel occlusion (2VO). After 2VO surgery, IMP (2.5, 5, and 10 mg/kg) was administered by intraperitoneal injection for 12 consecutive weeks to evaluate therapeutic effects. Cognitive function was verified by the Morris water maze. The neuronal morphological changes were examined via Hematoxylin-Eosin staining. Real-Time PCR and Western blot were used for detecting pro- and antiapoptotic biomarkers, and the hippocampus synaptic damage was examined by Transmission electron microscope. We revealed that 2VO-induced cognitive impairment, hippocampus CA1 neuron damage, apoptosis and synaptic damage. IMP-treatment significantly improved 2VO-induced cognitive deficits and hippocampus neuron damage. Molecular analysis revealed that IMP inhibited apoptosis through the down regulation of Bax, Caspase-3 and upregulation of Bcl-2. Meanwhile, IMP-treatment markedly improved synaptic ultrastructure morphology, increased the SAZ length, PSD thickness and up-regulated PSD-95 expression. Collectively, our findings demonstrated that IMP was effective in the treatment of 2VO-induced VD via inhibiting apoptosis of hippocampus neurons and reducing the synaptic plasticity destroy.

GJ-4 ameliorates memory impairment in focal cerebral ischemia/reperfusion of rats via inhibiting JAK2/STAT1-mediated neuroinflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Gardenia jasminoides J. Ellis (Fructus Gardenia) is a traditional Chinese medicine with diverse pharmacological functions, such as anti-inflammation, anti-depression, as well as improvement of cognition and ischemia brain injury. GJ-4 is a natural extract from Gardenia jasminoides J. Ellis (Fructus Gardenia) and has been proved to improve memory impairment in Alzheimer's disease (AD) mouse model in our previous studies.

AIM OF THE STUDY

This study aimed to evaluate the therapeutic effects of GJ-4 on vascular dementia (VD) and explore the potential mechanisms.

MATERIAL AND METHODS

In our experiment, a focal cerebral ischemia and reperfusion rat model was successfully developed by the middle cerebral artery occlusion and reperfusion (MCAO/R). GJ-4 (10 mg/kg, 25 mg/kg, 50 mg/kg) and nimodipine (10 mg/kg) were orally administered to rats once a day for consecutive 12 days. Learning and memory behavioral performance was assayed by step-down test and Morris water maze test. The neurological scoring test was performed to evaluate the neurological function of rats. 2,3,5-Triphenyltetrazolium chloride (TTC) staining and Nissl staining were respectively employed to determine the infarct condition and neuronal injury of the brain. Iba1 immunohistochemistry was used to show the activation of microglia. Moreover, the synaptic damage and inflammatory level were detected by Western blot.

RESULTS

GJ-4 could significantly improve memory impairment, cerebral infraction, as well as neurological deficits of VD rats induced by MCAO/R. Further research indicated VD-induced neuronal injury was alleviated by GJ-4. In addition, GJ-4 could protect synapse of VD rats by upregulating synaptophysin (SYP) expression, post synaptic density 95 protein (PSD95) expression, and downregulating N-Methyl-D-Aspartate receptor 1 (NMDAR1) expression. Subsequent investigation of the underlying mechanisms identified that GJ-4 could suppress neuroinflammatory responses, supported by inhibited activation of microglia and reduced expression of inflammatory proteins, which ultimately exerted neuroprotective effects on VD. Further mechanistic study indicated that janus kinase 2 (JAK2)/signal transducer and activator of transcription 1 (STAT1) pathway was inhibited by GJ-4 treatment.

CONCLUSION

These results suggested that GJ-4 might serve as a potential drug to improve VD. In addition, our study indicated that inhibition of neuroinflammation might be a promising target to treat VD.

Promotive role of microRNA‑150 in hippocampal neurons apoptosis in vascular dementia model rats

Cognitive impairment is one of the primary features of vascular dementia (VD). However, the specific mechanism underlying the regulation of cognition function in VD is not completely understood. The present study aimed to explore the effects of microRNA (miR)‑150 on VD. To determine the effects of miR‑150 on cognitive function and hippocampal neurons in VD model rats, rats were subjected to intracerebroventricular injections of miR‑150 antagomiR. The Morris water maze test results demonstrated that spatial learning ability was impaired in VD model rats compared with control rats. Moreover, compared with antagomiR negative control (NC), miR‑150 antagomiR alleviated cognitive impairment and enhanced memory ability in VD model rats. The triphenyltetrazolium chloride, Nissl staining and immunohistochemistry results further demonstrated that miR‑150 knockdown improved the activity of hippocampal neurons in VD model rats compared with the antagomiR NC group. To validate the role of miR‑150 in neurons in vitro, the PC12 cell line was used. The flow cytometry and Hoechst 33342/PI double staining results indicated that miR‑150 overexpression significantly increased cell apoptosis compared with the mimic NC group. Moreover, the dual‑luciferase reporter gene assay results indicated that miR‑150 targeted HOXA1 and negatively regulated HOXA1 expression. Therefore, the present study indicated that miR‑150 knockdown ameliorated VD symptoms by upregulating HOXA1 expression in vivo and in vitro.

Mechanism underlying treatment of ischemic stroke using acupuncture: transmission and regulation

The inflammatory response after cerebral ischemia/reperfusion is an important cause of neurological damage and repair. After cerebral ischemia/reperfusion, microglia are activated, and a large number of circulating inflammatory cells infiltrate the affected area. This leads to the secretion of inflammatory mediators and an inflammatory cascade that eventually causes secondary brain damage, including neuron necrosis, blood-brain barrier destruction, cerebral edema, and an oxidative stress response. Activation of inflammatory signaling pathways plays a key role in the pathological process of ischemic stroke. Increasing evidence suggests that acupuncture can reduce the inflammatory response after cerebral ischemia/reperfusion and promote repair of the injured nervous system. Acupuncture can not only inhibit the activation and infiltration of inflammatory cells, but can also regulate the expression of inflammation-related cytokines, balance the effects of pro-inflammatory and anti-inflammatory factors, and interfere with inflammatory signaling pathways. Therefore, it is important to study the transmission and regulatory mechanism of inflammatory signaling pathways after acupuncture treatment for cerebral ischemia/reperfusion injury to provide a theoretical basis for clinical treatment of this type of injury using acupuncture. Our review summarizes the overall conditions of inflammatory cells, mediators, and pathways after cerebral ischemia/reperfusion, and discusses the possible synergistic intervention of acupuncture in the inflammatory signaling pathway network to provide a foundation to explore the multiple molecular mechanisms by which acupuncture promotes nerve function restoration.

Acupuncture Improves White Matter Perfusion and Integrity in Rat Model of Vascular Dementia: An MRI-Based Imaging Study

White matter lesions induced by chronic cerebral hypoperfusion are associated with cognitive impairment in vascular dementia (VaD). Previous studies have shown that acupuncture can ameliorate the cognitive deficits of individuals with VaD. However, the neuroimaging mechanisms of acupuncture on white matter perfusion and integrity remain elusive. In this study, the VaD model was induced by bilateral common carotid arteries occlusion (BCCAO) in rats. Novel object recognition task and Morris water maze were performed to evaluate short-term memory and spatial learning and memory. Arterial spin labeling and diffusion tensor imaging (DTI) were used to measure the cerebral blood flow (CBF) and the white matter integrity. Pathological examinations detected the myelin loss and concomitant neuroinflammation. The results demonstrate that BCCAO rats with reduced CBF exhibited worse performance and altered DTI parameters, including decreased fractional anisotropy, increased radial diffusivity, and axial diffusivity in white matter regions. Acupuncture ameliorated cognitive impairment, increased CBF, and protected the myelin sheath integrity but not the axons of BCCAO rats. These protective effects of acupuncture on white matter were significantly correlated with improved CBF. Pathological examination confirmed that the loss of myelin basic protein and microglial accumulation associated IL-1β and IL-6 production were attenuated by acupuncture treatment. Our findings suggest that acupuncture protects cognitive function of BCCAO rats by improving white matter perfusion and integrity.

Acupuncture attenuates cognitive deficits through α7nAChR mediated anti-inflammatory pathway in chronic cerebral hypoperfusion rats

AIMS

Chronic cerebral hypoperfusion (CCH) elicits inflammatory response, which contributes to the pathology of cognitive impairment. Several studies demonstrate that the alpha-7 nicotinic acetylcholine receptor (α7nAChR) can be a key component to modulate the inflammatory responses. We have reported previously that acupuncture attenuated cognitive deficits induced by CCH. In present study, whether effect of acupuncture was related to α7nAChR mediated anti-inflammatory pathway in CCH rats was further explored.

MAIN METHODS

Acupuncture was performed in CCH rats induced by bilateral common carotid arteries occlusion. Neuronal injury, the activation of microglia, the release of inflammatory cytokines, the expression of α7nAChR, and the activation of JAK2/STAT3 signaling pathways were detected. Cognitive function and central inflammation were evaluated after the intraperitoneal injection of an α7nAChR agonist PNU282987, or intracerebroventricular injection of an α7nAChR antagonist α-bungarotoxin (α-BGT).

KEY FINDINGS

We found that there were neuronal damage and inflammation, accompanied with the decreased expressions of α7nAChR in the hippocampus under CCH condition. Acupuncture inhibited neuronal damage, activation of microglia, and inflammatory cytokines. The expressions of α7nAChR, together with its downstream JAK2/STAT3 pathways were up regulated by acupuncture. PNU282987 mimicked the anti-inflammatory and neuroprotective effects as well as the cognitive improvements of acupuncture. Meanwhile, the benefit effects of acupuncture above were blocked by α-BGT.

SIGNIFICANCE

It was demonstrated that acupuncture promoted cognitive function and afforded neuroprotective effects against inflammation via activation of α7nAChR and its downstream JAK2-STAT3 pathway in CCH rats. It provides a new insight for acupuncture as an anti-inflammatory intervention for cognitive impairment.

Scalp acupuncture for patients with vascular dementia: A protocol for systematic review and meta-analysis of randomized controlled trails

BACKGROUND

Vascular dementia (VD) is a kind of acquired intelligence impairment syndrome caused by a series of cerebrovascular factors leading to brain tissue damage. Scalp acupuncture is widely used to treating VD. However, there is no a systematic review has been used to assess the efficacy and safety of scalp acupuncture therapy for VD. Therefore, the purpose of this paper is to systematically evaluate the effects of scalp acupuncture on VD.

METHODS

We will search the following databases from their inception to July 2020: PubMed, Chinese National Knowledge Infrastructure (CNKI), Wan Fang Database, Embase, Medline, Chinese Biomedical Literature Database (CBM), EBSCO, Web of Science, Technology Periodical Database (VIP), the Chongqing VIP Chinese Science and Cochrane Library. At the same time, we will retrieve other resources including conference articles, and gray literature. The randomized controlled trials (RCTs) in English or Chinese associated with scalp acupuncture for VD will be included. Our study data collection and analysis will be conducted independently by 2 reviewers, and Rev Man V.5.3.5 statistical software will be used to performing meta-analysis.

RESULTS

This review research will provide a high-quality synthesis to evaluate the efficacy and safety of scalp acupuncture for patients with VD.

CONCLUSION

This study will provide available evidence to judge whether scalp acupuncture is an effective and safe intervention for patients with VD. It also will provide reliable evidence for its widespread application.

ETHICS AND DISSEMINATION

This systematic review will provide convincing evidence for both patients and clinicians. It does not require ethical approval and the results will be published in a peer-reviewed journal.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/7CYZR.

Targeting Transcription Factor Nrf2 (Nuclear Factor Erythroid 2-Related Factor 2) for the Intervention of Vascular Cognitive Impairment and Dementia

Vascular cognitive impairment and dementia (VCID) is an age-related, mild to severe mental disability due to a broad panel of cerebrovascular disorders. Its pathobiology involves neurovascular dysfunction, blood-brain barrier disruption, white matter damage, microRNAs, oxidative stress, neuroinflammation, and gut microbiota alterations, etc. Nrf2 (Nuclear factor erythroid 2-related factor 2) is the master regulator of redox status and controls the transcription of a panel of antioxidative and anti-inflammatory genes. By interacting with NF-κB (nuclear factor-κB), Nrf2 also fine-tunes the cellular oxidative and inflammatory balance. Aging is associated with Nrf2 dysfunction, and increasing evidence has proved the role of Nrf2 in mitigating the VCID process. Based on VCID pathobiologies and Nrf2 studies from VCID and other brain diseases, we point out several hypothetical Nrf2 targets for VCID management, including restoration of endothelial function and neurovascular coupling, preservation of blood-brain barrier integrity, reduction of amyloidopathy, promoting white matter integrity, and mitigating oxidative stress and neuroinflammation. Collectively, the Nrf2 pathway could be a promising direction for future VCID research. Targeting Nrf2 would shed light on VCID managing strategies.

Standardizing therapeutic parameters of acupuncture in vascular dementia rats

INTRODUCTION

Despite acupuncture having been successfully used for the clinical treatment for vascular dementia in Asian countries for centuries, scientifically rigorous evidence is lacking for standardizing therapeutic parameters. To address this problem, it is necessary to examine the parameters of acupuncture using scientific methodology. The goal of this study is to investigate various therapeutic parameters, including manipulation, retention, and frequency of acupuncture, and their contribution to the efficacy of acupuncture in VD.

METHODS

We selected needle retention, treatment frequency, and needle rotation as the parameters. Acupuncture was performed on acupoints ST36 and GV20. Morris Water Maze was selected to assess the effect of acupuncture on cognitive function and Nissl staining indicated the hippocampal neuronal damage in VD rats.

RESULTS

Acupuncture stimulation resulted in a significant improvement in the spatial learning and memory deficit and reversed neuronal damage in the hippocampus. The approach of needle retention with 10 min, rotation for 30s every 5 min or daily treatment with acupuncture was more effective than nonretention, nonrotation, or alternative day treatment group.

CONCLUSION

This study demonstrated that needle retention, treatment frequency, and needle manipulation are important factors in improving the learning and memory as well as reducing the neuronal damage of the hippocampus in a rat VD model. These findings strongly suggest that the appropriate therapeutic parameters could significant influence the efficiency in animal experiments.

Acupuncture Attenuates Inflammation in Microglia of Vascular Dementia Rats by Inhibiting miR-93-Mediated TLR4/MyD88/NF-κB Signaling Pathway

Background

It is widely accepted that inflammation may contribute to cognitive impairment in patients with vascular dementia (VD). Our prior clinical researches have reported that acupuncture can alleviate cognitive function in VD, but the underlying mechanisms are still unclear. The purpose of this research was to explore whether acupuncture alleviates cognitive impairment by suppressing the microRNA-93- (miR-93-) mediated Toll-like receptor (TLR) signaling pathway, which triggers inflammatory responses in the central nervous system.

Methods

VD was established by permanent bilateral common carotid artery occlusion in male Wistar rats. Three days after operation, the rats began daily treatment with acupuncture for two weeks. The levels of miR-93, Toll-like receptors (TLR2 and TLR4), intracellular signaling molecules (myeloid differentiation factor 88 (MyD88) and nuclear factor-kappa B (NF-κB)), and inflammatory cytokines were subsequently detected. TLR4 colocalized with neurons, microglia, and astrocytes in the hippocampus was evaluated. Neuroinflammation and cognitive function were determined after intracerebroventricular injection of TLR4 antagonist TAK-242 or agonist lipopolysaccharide (LPS) with or without acupuncture.

Results

We found that acupuncture notably repressed the expression of inflammatory cytokines in the hippocampus and plasma of VD rats. The expression of TLR4, but not TLR2, was markedly downregulated by acupuncture, accompanied by a decrease in miR-93 and MyD88/NF-κB signaling pathway activation. The overexpression of TLR4 in microglia, but not in astrocytes and neurons, was reversed by acupuncture. Furthermore, intracerebroventricular injection of TAK-242 had similar effects to acupuncture on inflammation and cognitive function, while LPS injection abolished the beneficial effects of acupuncture.

Conclusions

Taken together, these findings provide evidence that acupuncture attenuates cognitive impairment associated with inflammation through inhibition of the miR-93-mediated TLR4/MyD88/NF-κB signaling pathway in experimental VD. Acupuncture serves as a promising alternative therapy and may be an underlying TLR4 inhibitor for the treatment of VD.

Electroacupuncture Improves Cognition in Rats With Sepsis-Associated Encephalopathy

BACKGROUND

Sepsis-associated encephalopathy (SAE) is a common complication of sepsis. Although sepsis is effectively managed with the administration of antibiotics and source control, which may include surgical intervention, SAE usually leads to prolonged cognitive dysfunction affecting the quality of life of the patients. In this study, we investigated the possible effect of electroacupuncture (EA) on cognition in a model of SAE induced by cecal ligation and puncture (CLP).

MATERIALS AND METHODS

The rats were randomly divided into four groups: the control group, the CLP group, the CLP with EA treatment group (CLP + EA), and the CLP with sham EA treatment group (CLP + sham EA). EA at DU20, LI11, and ST36 or sham EA was performed 30 min daily for 10 consecutive days starting from 2 days before CLP. Then cognitive function was examined by the Morris water maze test. On day 14 after CLP surgery, the synaptic injury, neuron loss, and oxidative stress were studied.

RESULTS

Rats with EA treatment showed improved survival rate, spatial learning, and memory abilities. The dendritic spine density, the synaptic proteins, and the hippocampal neuron number were also increased after EA treatment. Furthermore, EA suppressed oxidative stress through regulating the level of malondialdehyde and superoxide dismutase and enhanced the expression of antioxidant nuclear factor erythroid-2-related factor-2 and hemeoxygenase-1. But sham EA did not have the same effect.

CONCLUSIONS

EA may protect against SAE-induced cognitive dysfunction by inhibiting synaptic injury, neuronal loss, and oxidative stress, and the nuclear factor erythroid-2-related factor-2/hemeoxygenase-1 signaling pathway may be involved in this effect.

Evaluation of Neuroprotective Effects of Quercetin against Aflatoxin B1-Intoxicated Mice

Simple Summary

Aflatoxin B1 (AFB1) is a mycotoxin commonly present in feed, characterized by several toxic effects. AFB1 has been described as being responsible for naturally occurring animal kidney disorders. In addition, AFB1 seems to have a neurotoxical effect that leads to memory impairment behavior. AFB1 toxicity involves the induction of the oxidative stress pathway, rising lipid peroxidation, and it decreases antioxidant enzyme levels. Hence, in our research, we wanted to evaluate the potential protective effects of quercetin in AFB1-mediated toxicity in the brain and the ameliorative effect on behavioral alterations. This antioxidant effect of quercetin in the brains of AFB1-intoxicated mice is reflected in better cognitive and spatial memory capacity, as well as a better profile of anxiety and lethargy disorders. In conclusion, our study suggests that quercetin exerts a preventive role against oxidative stress by promoting antioxidative defense systems and limiting lipid peroxidation.

Abstract

Aflatoxin B1 (AFB1) is a mycotoxin commonly present in feed, characterized by several toxic effects. AFB1 seems to have a neurotoxical effect that leads to memory impairment behavior. AFB1 toxicity involves the induction of the oxidative stress pathway, rising lipid peroxidation, and it decreases antioxidant enzyme levels. Hence, in our research, we wanted to evaluate the potential protective effects of quercetin 30 mg/kg in AFB1-mediated toxicity in the brain and the ameliorative effect on behavioral alterations. Oral supplementation with quercetin increased glutathione peroxidase (GSH) levels, superoxidedismutase (SOD) activity and catalase (CAT) in the brain, and it reduced lipid peroxidation in AFB1-treated mice. This antioxidant effect of quercetin in the brains of AFB1-intoxicated mice is reflected in better cognitive and spatial memory capacity, as well as a better profile of anxiety and lethargy disorders. In conclusion, our study suggests that quercetin exerts a preventive role against oxidative stress by promoting antioxidative defense systems and limiting lipid peroxidation.

Effect of Acupuncture on Oxidative Stress Induced by Cerebral Ischemia-Reperfusion Injury

In this article, we review how acupuncture regulates oxidative stress to prevent ischemia–reperfusion injury. We electronically searched databases, including PubMed, Clinical Key and the Cochrane Library, from their inception to November 2019 by using the following medical subject headings and keywords: acupuncture, ischemia-reperfusion injury, oxidative stress, reactive oxygen species, and antioxidants. We concluded that acupuncture is effective in treating oxidation after ischemia-reperfusion injury. In addition to increasing the activity of antioxidant enzymes and downregulating the generation of reactive oxygen species (ROS), acupuncture also repairs the DNA, lipids, and proteins attacked by ROS and mediates downstream of the ROS pathway to apoptosis.

The maintenance effect of acupuncture on breast cancer-related menopause symptoms: a systematic review

Background: Acupuncture has been used for many breast cancer treatment-related problems, but how long the effect lasts is unknown. This meta-analysis aims to evaluate how long the effect of acupuncture on breast cancer-related hot flushes and menopause symptoms lasts.Methods: The research design followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement, without language restrictions. Seven databases from inception through February 2019 were accessed; only randomized clinical trials (RCTs) that examined the maintenance effect of acupuncture on hot flushes or menopause symptoms after treatment were included. Cochrane criteria were followed and RevMan 5.2 software was used to analyze trials.Results: In total, 943 patients from 13 RCTs were analyzed. The meta-analysis showed that acupuncture had no significant long-term maintenance effect on the frequency or severity of hot flushes (p = 0.29; p = 0.34), but had a significant 3-month maintenance effect of ameliorating menopause symptoms at 3 months after treatment ended (p = 0.001). No adverse events were reported.Conclusions: Acupuncture significantly alleviated menopause symptoms for at least 3 months, but not hot flushes. Breast cancer patients concerned about the adverse effects of hormone therapy could consider acupuncture as an alternative. Additional acupuncture at 3 months after the initial treatment course could be considered. A large-scale study may help to define the optimal guideline for this issue.

Electroacupuncture Pretreatment Ameliorates PTSD-Like Behaviors in Rats by Enhancing Hippocampal Neurogenesis via the Keap1/Nrf2 Antioxidant Signaling Pathway

Electroacupuncture (EA) pretreatment is a clinically useful therapy for several brain disorders. However, whether and via which exact molecular mechanisms it ameliorates post-traumatic stress disorder (PTSD) remains unclear. In the present study, rats received EA stimulation for seven consecutive days before exposure to enhanced single prolonged stress (ESPS). Anxiety-like and fear learning behaviors; hippocampal neurogenesis; the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (keap1), and heme oxygenase 1 (HO-1); and the activity of AMP-activated kinase (AMPK) were evaluated at 14 days after ESPS. EA pretreatment improved hippocampal neurogenesis and ameliorated anxiety-like behaviors in ESPS-treated rats. EA pretreatment also increased the expression of Nrf2 and HO-1 and the activity of AMPK. Furthermore, Nrf2 knockdown by a short hairpin RNA affected anxiety-like behaviors and expression of neuroprotective markers (BDNF, DCX) in a manner similar to ESPS alone and dampened the neuroprotective effects of EA pretreatment. In contrast, Keap1 knockdown increased the expression of HO-1, improved hippocampal neurogenesis, and alleviated PTSD-like behaviors. Altogether, our results suggest that EA pretreatment ameliorates ESPS-induced anxiety-like behaviors and prevents hippocampal neurogenesis disruption in a rat model of PTSD possibly through regulation of the keap1/Nrf2 antioxidant defense pathway.

Effectiveness of Acupuncture for Alzheimer's Disease: An Updated Systematic Review and Meta-analysis

Acupuncture has reportedly improved memory and cognitive impairment in both animal and clinical studies. It may be an effective treatment for Alzheimer's disease (AD). The purpose of this meta-analysis was to review the effectiveness of acupuncture for the treatment of AD. Eight databases were searched for articles published up to and including July 2017, and 13 studies fulfilling the inclusion criteria were identified. The main outcomes assessed were clinical efficacy rate, Mini-Mental State Examination score, Ability of Daily Living Scale score, Alzheimer's Disease Assessment Scale-Cognition score, Hasegawa's Dementia Scale (HDS) score, and adverse events. The methodological quality of the articles was assessed using Cochrane's risk of bias. All the studies compared the efficacy of acupuncture with that of medication, and were published in Chinese journals. Meta-analysis revealed that acupuncture yielded positive results as determined via all the indexes scored except the HDS (95% CI -0.26 to 0.90, Z=0.35, P=0.73). Only one of the studies reported adverse events associated with acupuncture and medication. The rate of adverse events in the medication group was 13%. In most of the studies assessed in the current meta-analysis, acupuncture alone was better than conventional western medicines for the treatment of AD.

The effects of acupuncture and electroacupuncture on Parkinson's disease: Current status and future perspectives for molecular mechanisms

Among the progressive neurodegenerative disorders, Parkinson's disease (PD) is the second most common. Different factors have critical role in pathophysiology of PD such as apoptosis pathways, inflammatory cytokines, oxidative stress, and neurotransmitters and its receptors abnormalities. Acupuncture and electroacupuncture were considered as nondrug therapies for PD. Although numerous studies has been conducted for assessing the mechanism underlying electroacupuncture and acupuncture, various principal aspects of these treatment procedures remain not well-known. There have also been few investigations on the molecular mechanism of acupuncture and electroacupuncture therapy effects in PD. This review evaluates the effects of electroacupuncture and acupuncture on the molecular mechanism in PD.

Protective effects of sulforaphane in experimental vascular cognitive impairment: Contribution of the Nrf2 pathway

The major pathophysiological process of vascular cognitive impairment (VCI) is chronic cerebral ischemia, which causes disintegration of the blood-brain barrier (BBB), neuronal death, and white matter injury. This study aims to test whether sulforaphane (Sfn), a natural activator of nuclear factor erythroid 2-related factor 2 (Nrf2), reduces the chronic ischemic injury and cognitive dysfunction after VCI. Experimental VCI was induced in rats by permanent occlusion of both common carotid arteries for six weeks. This procedure caused notable neuronal death in the cortex and hippocampal CA1, myelin loss in the corpus callosum and hippocampal fimbria, accumulation of myelin debris in the corpus callosum, and remarkable cognitive impairment. Sfn treatment alleviated these ischemic injuries and the cognitive dysfunction. Sfn-mediated neuroprotection was associated with enhanced activation of Nrf2 and upregulation of heme oxygenase 1. Sfn also reduced neuronal and endothelial death and maintained the integrity of BBB after oxygen-glucose deprivation in vitro in an Nrf2 dependent manner. Furthermore, Nrf2 knockdown in endothelial cells decreased claudin-5 protein expression with downregulated claudin-5 promoter activity, suggesting that claudin-5 might be a target gene of Nrf2. Our results demonstrate that Sfn provides robust neuroprotection against chronic brain ischemic injury and may be a promising agent for VCI treatment.

N-Palmitoylethanolamine-oxazoline (PEA-OXA): A new therapeutic strategy to reduce neuroinflammation, oxidative stress associated to vascular dementia in an experimental model of repeated bilateral common carotid arteries occlusion

AIM

Recent studies revealed that pharmacological modulation of NAE-hydrolyzing acid amidase (NAAA) can be achieved with PEA oxazoline (PEA-OXA). Hence, the aim of the present work was to thoroughly evaluate the anti-inflammatory and neuroprotective effects of PEA-OXA in an experimental model of vascular dementia (VaD) induced by bilateral carotid arteries occlusion. At 24 h after VaD induction, animals were orally administered with 10 mg/kg of PEA-OXA daily for 15 days.

RESULTS

Brain tissues were handled for histological, immunohistochemical, western blot, and immunofluorescence analysis. PEA-OXA treatment evidently reduced the histological alterations and neuronal death induced by VaD and additionally improved behavioral deficits. Further, PEA-OXA decreased GFAP and Iba-1, markers of astrocytes, and microglia activation, as well as increased MAP-2, a marker of neuron development. Moreover, PEA-OXA reduced oxidative stress, modulated Nrf2-mediated antioxidant response, and inhibited the apoptotic process.

INNOVATION

Some drugs may demonstrate their healing potential by regulating neuroinflammation, rather than by their habitually attributed actions only. Palmitoylethanolamide (PEA) is a prototype ALIAmide, well-known for its analgesic, anti-inflammatory, and neuroprotective properties. The inhibition of PEA degradation by targeting NAAA, its catabolic enzyme, is a different approach for treating neuroinflammation. This research offers new insight into the mechanism of PEA-OXA-induced neuroprotection.

CONCLUSION

Thus, the modulation of intracellular NAAA by PEA-OXA could offer a novel means of controlling neuroinflammatory conditions associated with VaD.

Chotosan ameliorates cognitive impairment and hippocampus neuronal loss in experimental vascular dementia via activating the Nrf2-mediated antioxidant pathway

Recent studies suggested that Chotosan has ameliorative effects on vascular dementia through antioxidative pathways. Nevertheless, no systematic pharmacological research was conducted to evaluate the contribution of nuclear factor-E2-related factor 2 (Nrf2), a crucial regulator of antioxidative system, on Chotosan-induced neuroprotection invascular dementia. The present study aimed to investigate the neuroprotective effect of Chotosan on vascular dementia and reveal the possible molecular mechanism involving Nrf2. We found that Chotosan treatment could ameliorate memory impairment and reduce neuron cell loss induced by common carotid artery occlusion surgery. Furthermore, Chotosan could significantly reverse reactive oxygen species production, neuronal apoptosis and microglia over-activation in hippocampus. In addition, Chotosan enhanced Nrf2 expression and its nuclear translocation as well as its downstream antioxidant protein expression, NAD(P)H/quinone oxidoreductase 1 and heme oxygenase-1. These findings suggest that Chotosan exert neuroprotection in an animal model of vascular dementia via activating Nrf2-mediated antioxidant pathway. Chotosan may serve as a potential candidate and promising Nrf2 activator for treating vascular dementia.

Effects of acupuncture on vascular dementia (VD) animal models: a systematic review and meta-analysis

BACKGROUND

Vascular dementia is the second most common type of dementia that causes cognitive dysfunction. Acupuncture, an ancient therapy, has been mentioned for the treatment of vascular dementia in previous studies. This study aimed to evaluate the effects of acupuncture in animal models of vascular dementia.

METHODS

Experimental animal studies of treating vascular dementia with acupuncture were gathered from Embase, PubMed and Ovid Medline (R) from the dates of the databases' creation to December 2016. We adopted the CAMARADES 10-item checklist to evaluate the quality of the included studies. The Morris water maze test was considered as an outcome measure. The software Stata12.0 was used for the meta-analysis. Heterogeneity was examined using I² statistics, and we conducted subgroup analyses to determine the causes of heterogeneity for escape latency and duration in original platform.

RESULTS

Sixteen studies involving 363 animals met the inclusion criteria. The included studies scored between 4 and 8 points, and the mean was 5.44. The results of the meta-analysis indicated remarkable differences with acupuncture on increasing the duration in the former platform quadrant both in EO models (SMD = 1.56, 95% CI: 1.02 ~ 2.11; p < 0.00001) and 2-VO models (SMD 4.29, 95% CI 3.23 ~ 5.35; p < 0.00001) compared with the control groups.

CONCLUSIONS

Acupuncture may be effective in improving cognitive function in vascular dementia animal models. The mechanisms of acupuncture for vascular dementia are multiple such as anti-apoptosis, antioxidative stress reaction, and metabolism enhancing of glucose and oxygen.