Electroacupuncture ameliorates cognitive impairment through inhibition of NF-κB-mediated neuronal cell apoptosis in cerebral ischemia-reperfusion injured rats

The role and therapeutic potential of nuclear factor κB (NF-κB) in ischemic stroke

Stroke is a prevalent cerebrovascular condition with a global impact, causing significant rates of illness and death. Despite extensive research, the available treatment options for stroke remain restricted. Hence, it is crucial to gain a deeper understanding of the molecular mechanisms associated with the onset and advancement of stroke in order to establish a theoretical foundation for novel preventive and therapeutic approaches. NF-κB, also known as nuclear factor κB, is a transcription factor responsible for controlling the expression of numerous genes and plays a crucial role in diverse physiological processes. NF-κB is triggered and regulates neuroinflammation and other processes after stroke, promoting the generation of cytokine storms and contributing to the advancement of ischemic stroke (IS). Therefore, NF-κB could potentially play a vital role in stroke by regulating diverse pathophysiological processes. This review provides an overview of the functions of NF-κB in stroke and its governing mechanisms. In addition, our attention is directed towards various potential therapies that aim to inhibit the NF-κB signaling pathway in order to offer valuable insights for the advancement of innovative treatment approaches for stroke.

Global trends and development of acupuncture for stroke: A review and bibliometric analysis

The objective of this review is to elaborate on the status, hotspots, and trends of researches on acupuncture for stroke over the past 26 years. Publications about acupuncture for stroke were downloaded from the Web of Science Core Collection, and these papers were published up to December 31, 2022. A bibliometric analysis of acupuncture for stroke was conducted by CiteSpace (6.2.R4) and VOSviewer (1.6.17). In this study, VOSviewer was used for visual analysis of countries, institutions, authors, journals, keywords, and co-cited references. CiteSpace was used to draw a keyword burst map and a co-cited reference burst map. A total of 534 papers were obtained from the Web of Science Core Collection. The number of papers per year showed a rapid upward trend. The most productive country and institution in this field were China (452) and the Fujian University of Traditional Chinese Medicine (43), respectively. Tao Jing had the highest number of articles (34), and EZ Longa was the most popular author (129 co-citations). Neural Regeneration Research (51) was the most productive journal, and Stroke (1346) was the most co-cited journal. An paper written by EZ Longa was the most influential reference, with the highest citation count. The hotspots and frontiers of this area of research were focused on the mechanisms of acupuncture, especially its neural regenerative or neuroprotective effects. This study used CiteSpace and VOSviewer for bibliometric analysis to provide researchers with information on the research status, hotspots, and trends in acupuncture for stroke research over the past 26 years.

The effects and mechanisms of acupuncture for post-stroke cognitive impairment: progress and prospects

Stroke is one of the important causes of both disability and death worldwide, which is very common in older adults. Post-stroke cognitive impairment (PSCI) is a common secondary damage of stroke, which is the main cause of long-term disability and decreased quality of life in stroke patients, which brings a heavy burden to society and families. Acupuncture, as one of the oldest and widely used worldwide techniques in Chinese medicine, is recommended by the World Health Organization (WHO) as an alternative and complementary strategy for improving stroke care. This review comprehensively summarizes literature from the last 25 years, showing that acupuncture can exert strong beneficial effect on PSCI. The mechanisms of acupuncture on PSCI involves anti-neuronal apoptosis, promoting synaptic plasticity, alleviating central and peripheral inflammatory reactions, and regulating brain energy metabolism disorders (including improving cerebral blood flow, glucose utilization and mitochondrial structure and function, etc.), etc. The effects and mechanisms of acupuncture on PSCI reviewed in this study provides scientific and reliable evidence for acupuncture application for PSCI.

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.

Post-stroke cognitive impairment and synaptic plasticity: A review about the mechanisms and Chinese herbal drugs strategies

Post-stroke cognitive impairment, is a major complication of stroke, characterized by cognitive dysfunction, which directly affects the quality of life. Post-stroke cognitive impairment highlights the causal relationship between stroke and cognitive impairment. The pathological damage of stroke, including the increased release of excitatory amino acids, oxidative stress, inflammatory responses, apoptosis, changed neurotrophic factor levels and gene expression, influence synaptic plasticity. Synaptic plasticity refers to the activity-dependent changes in the strength of synaptic connections and efficiency of synaptic transmission at pre-existing synapses and can be divided into structural synaptic plasticity and functional synaptic plasticity. Changes in synaptic plasticity have been proven to play important roles in the occurrence and treatment of post-stroke cognitive impairment. Evidence has indicated that Chinese herbal drugs have effect of treating post-stroke cognitive impairment. In this review, we overview the influence of pathological damage of stroke on synaptic plasticity, analyze the changes of synaptic plasticity in post-stroke cognitive impairment, and summarize the commonly used Chinese herbal drugs whose active ingredient or extracts can regulate synaptic plasticity. This review will summarize the relationship between post-stroke cognitive impairment and synaptic plasticity, provide new ideas for future exploration of the mechanism of post-stroke cognitive impairment, compile evidence of applying Chinese herbal drugs to treat post-stroke cognitive impairment and lay a foundation for the development of novel formulas for treating post-stroke cognitive impairment.

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.

"Adjust Zang and arouse spirit" electroacupuncture ameliorates cognitive impairment by reducing endoplasmic reticulum stress in db/db mice

Introduction

Diabetic cognitive impairment (DCI) is a chronic complication of the central nervous system (CNS) caused by diabetes that affects learning and memory capacities over time. Recently, acupuncture has been shown to improve cognitive impairment in streptozotocin-induced diabetic rats. However, the effects of electroacupuncture on DCI and its underlying mechanism have not yet been elucidated in detail.

Methods

In this study, we used db/db mice as DCI animal models which showed low cognitive, learning and memory functions. Electroacupuncture significantly ameliorated DCI, which is reflected by better spatial learning and memory function using behavioral tests. The db/db mice with cognitive impairment were randomly divided into a model group (Mod) and an electroacupuncture treatment group (Acup), while db/m mice were used as a normal control group (Con). First, the mice were subjected to behavioural tests using the Morris water maze (MWM), and body weight, blood glucose, insulin, triglycerides (TG) and total cholesterol (TC) were observed; HE, Nissl, and TUNEL staining were used to observe the morphological changes and neuronal apoptosis in the mice hippocampus; Finally, Western blot and rt-PCR were applied to detect the essential proteins and mRNA of ERS and insulin signalling pathway, as well as the expression levels of Tau and Aβ.

Results

Electroacupuncture significantly ameliorated DCI, which is reflected by better spatial learning and memory function using behavioral tests. Moreover, electroacupuncture attenuated diabetes-induced morphological structure change, neuronal apoptosis in the hippocampus of db/db mice. Our results revealed that electroacupuncture could regulate the expression levels of Tau and Aβ by improving hippocampal ERS levels in db/db mice, inhibiting JNK activation, attenuating IRS1 serine phosphorylation, and restoring normal transduction of the insulin signaling pathway.

Discussion

In summary, ERS and insulin signaling pathway paly causal roles in DCI development. Electroacupuncture can significantly alleviate the pathogenesis of DCI, improve mice's learning and memory ability, and improve cognitive dysfunction. This study adds to our understanding of the effect of acupuncture on DCI and opens the door to further research on DCI.

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.

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.

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.

The Preventive Effect of Transcutaneous Electrical Acupoint Stimulation on Postoperative Delirium in Elderly Patients with Time Factors: A Randomized Trial

Objectives: There is currently no exact and effective treatment for postoperative delirium (POD). The purpose of this study was to observe the effect of transcutaneous electrical acupoint stimulation (TEAS) before surgery and during surgery in elderly patients with POD. Materials and Methods: A total of 90 patients were randomly divided into three groups: a preoperative TEAS group (group E1), an intraoperative TEAS group (group E2), and a control group (group C). In group E1, TEAS was applied at the Shenting, Baihui, bilateral Neiguan, and Hegu points for 30 min 1 day before surgery and before the induction of anesthesia. In group E2, TEAS was applied during surgery. In group C, electrodes were applied to the points just cited, but no electric stimulation was administered. The incidence of delirium was assessed within 5 days after surgery, and the plasma concentration of propofol at bispectral index (BIS) = 50 was recorded. Blood samples were collected to measure neuron-specific enolation (NSE), tumor necrosis factor-α (TNF-α), and interleukin (IL)-1β 1 day before surgery and 1 and 5 days after surgery. Results: The incidence of delirium in group E1 was decreased in comparison with group C and group E1 (both p < 0.05). The propofol plasma concentration at BIS = 50 in group E1 was also decreased in comparison with group C and group E2 (both p < 0.05). Compared with group C, the concentrations of NSE, TNF-α, and IL-1β in plasma were decreased in group E1 and group E2 1 and 5 days after surgery (both p < 0.05), and the concentrations of NSE and IL-1β in plasma in group E1 were decreased 1 and 5 days after surgery in comparison with group E2. Conclusion: The TEAS can reduce the dosage of propofol required during surgery and the occurrence of delirium after surgery. Its mechanism may be related to inhibiting inflammation response and alleviating brain injury. Compared with intraoperative application, the effect of preconditioning with TEAS before surgery is better. Trial Registration: ChiCTR-INR-17012501. Date of registration: August 29, 2017.

Treatment of Modified Dahuang Fuzi Decoction on Cognitive Impairment Induced by Chronic Kidney Disease through Regulating AhR/NF-κB/JNK Signal Pathway

Aim

An increasing widespread of chronic kidney disease (CKD) has been established lately around the globe. In addition to renal function loss, CKD can also cause cognitive impairment (CI). Modified Dahuang Fuzi Decoction (MDFD) is used as a traditional Chinese therapy for CKD. The effect of MDFD on cognitive impairment induced by chronic kidney disease (CKD-CI), and therapeutic mechanisms were investigated.

Methods

The CKD animals' model was developed in the 5/6 nephrectomized mice. Sham operation and model groups received normal saline, while positive control and MDFD high/medium/low dose received Aricept (10 mg/kg/day) and different doses of MDFD (24, 16, and 8 g/kg/day), respectively. Cognitive function was detected with the Morris water maze test, while related factors were determined by ELISA. Histopathology and mechanism were studied using HE, western blot, and qRT-PCR.

Results

In the CKD-CI mice model, escape latency decreased significantly, whereas time of crossing platform and time spent within the platform quadrant increased substantially (P < 0.05) after MDFD treatment. Moreover, renal function and brain injury in CKD-CI improved dose-dependently, while the effect of MDFD-L was worse. Proteins such as aryl hydrocarbon receptor, nuclear factor-kappa B and c-Jun-N-terminal kinase, and mRNA in the kidney and brain of all the treatment groups decreased substantially (P < 0.05). Expression of tropomyosin receptor kinase B and brain-derived neurotrophic factor at protein and mRNA levels in the brain were significantly enhanced (P < 0.05).

Conclusion

MDFD presumably activated the BDNF/TrkB pathway by inhibiting the AhR/NF-κB/JNK signaling pathway to treat CKD-CI.

Visualization and Analysis of the Mapping Knowledge Domain of Acupuncture and Central Nervous System Cell Apoptosis

Chinese acupuncture therapy has demonstrated good clinical effects on neurological diseases and is widely used internationally. In the past 20 years, an increasing number of researchers around the world have devoted themselves to the study of the effect and mechanism of acupuncture for the treatment of central nervous system cell apoptosis. To discover the current research status of acupuncture-induced antiapoptosis in the central nervous system, we used the method of scientometric research and data visualization software to visually analyse 155 articles. The findings are as follows. First, the antiapoptosis effects of acupuncture in the central nervous system have received increasing attention overseas and domestically. China and the United States have leading positions in this research field. Second, 5 stable and high-yielding research teams have been formed in the field of acupuncture-induced antiapoptosis. The main research directions of these teams are electroacupuncture (EA) pretreatment for the central nervous system cell apoptosis, acupuncture for antineuronal apoptosis in vascular dementia, EA regulation of related signalling pathways, EA regulation of nerve cell apoptosis and autophagy after stroke, and EA regulation of the MAPK signalling pathway. Researchers on teams with more extensive cooperation have more research results and better research continuity. Third, there are diversified research hotspots. The original research hotspots are still receiving attention, and new hotspots have emerged in recent years.

Electroacupuncture Ameliorates Cognitive Impairment Through the Inhibition of NLRP3 Inflammasome Activation by Regulating Melatonin-Mediated Mitophagy in Stroke Rats

Previous studies found that electroacupuncture (EA) at the Shenting (DU24) and Baihui (DU20) acupoints alleviates cognitive impairment in cerebral ischemia-reperfusion (I/R) injury rats. Nonetheless, the mechanisms of the anti-inflammatory effects of EA are unclear. Cerebral I/R injury was induced in rats by middle cerebral artery occlusion (MCAO). Following I/R injury, the rats underwent EA therapy at the Shenting (DU24) and Baihui (DU20) acupoints for seven successive days. The Morris water maze test, magnetic resonance imaging (MRI) and molecular biology assays were utilized to assess the establishment of the rat stroke model with cognitive impairment and the therapeutic effect of EA. EA treatment of rats subjected to MCAO showed a significant reduction in infarct volumes accompanied by cognitive recovery, as observed in Morris water maze test outcomes. The possible mechanisms by which EA treatment attenuates cognitive impairment are by regulating endogenous melatonin secretion through aralkylamine N-acetyltransferase gene (AANAT, a rate-limiting enzyme of melatonin) synthesis in the pineal gland in stroke rats. Simultaneously, through melatonin regulation, EA exerts neuroprotective effects by upregulating mitophagy-associated proteins and suppressing reactive oxygen species (ROS)-induced NLRP3 inflammasome activation after I/R injury. However, melatonin receptor inhibitor (luzindole) treatment reversed these changes. The findings from this research suggested that EA ameliorates cognitive impairment through the inhibition of NLRP3 inflammasome activation by regulating melatonin-mediated mitophagy in stroke rats.

Electroacupuncture treatment ameliorated the long-term cognitive impairment via activating eNOS/NO pathway and related Aβ downregulation in sepsis-survivor mice

OBJECTIVE

Sepsis is a major challenge in intensive care unit worldwide and the septic survivors are left with long-term cognitive deficits. This work aims to explore the effects of electroacupuncture (EA) on long-term cognitive function and its underlying mechanism in sepsis-survivor mice.

METHODS

Sepsis was induced by cecal ligation and puncture in C57BL/6 male mice. Seven days post-surgery, sepsis-survivor mice were treated with EA or nonacupoint EA for 17 days twice daily. Then, cognitive function was evaluated by Morris water maze task. The hippocampus tissue were collected from the mice at 30 days post-surgery. The level of nitric oxide and the expression of endothelial nitric oxide (eNOS), phospho-eNOS (p-eNOS), and amyloid β-peptide (Aβ) were measured.

RESULTS

Compared with the sham-operated control, sepsis-survivors had significant cognitive deficits evidenced by the increased time of escape latency and reduced crossing number in Morris water maze task, as well as lower NO and p-eNOS level and higher Aβ level. EA treatment at GV20 and ST36 acupoints but not at a nonacupoint improved the cognitive function, increased the NO and p-eNOS level, and decreased Aβ generation; while eNOS inhibitor (l-NAME) undermined the efficacy of EA treatment.

CONCLUSION

In conclusion, repeated EA treatment could ameliorate the long-term cognitive impairment via manipulating the expression of p-eNOS and related Aβ in sepsis-survivor mice.

Electroacupuncture Pretreatment Prevents Cognitive Impairment Induced by Cerebral Ischemia-Reperfusion via Adenosine A1 Receptors in Rats

A previous study has demonstrated that pretreatment with electroacupuncture (EA) induces rapid tolerance to focal cerebral ischemia. In the present study, we investigated whether adenosine receptor 1 (A1 R) is involved in EA pretreatment-induced cognitive impairment after focal cerebral ischemia in rats. Two hours after EA pretreatment, focal cerebral ischemia was induced by middle cerebral artery occlusion for 120 min in male Sprague-Dawley rats. The neurobehavioral score, cognitive function [as determined by the Morris water maze (MWM) test], neuronal number, and the Bax/Bcl-2 ratio was evaluated at 24 h after reperfusion in the presence or absence of CCPA (a selective A1 receptor agonist), DPCPX (a selective A1 receptor antagonist) into left lateral ventricle, or A1 short interfering RNA into the hippocampus area. The expression of the A1 receptor in the hippocampus was also investigated. The result showed that EA pretreatment upregulated the neuronal expression of the A1 receptor in the rat hippocampus at 90 min. And EA pretreatment reversed cognitive impairment, improved neurological outcome, and inhibited apoptosis at 24 h after reperfusion. Pretreatment with CCPA could imitate the beneficial effects of EA pretreatment. But the EA pretreatment effects were abolished by DPCPX. Furthermore, A1 receptor protein was reduced by A1 short interfering RNA which attenuated EA pretreatment-induced cognitive impairment.

Orexin-A alleviates astrocytic apoptosis and inflammation via inhibiting OX1R-mediated NF-κB and MAPK signaling pathways in cerebral ischemia/reperfusion injury

Orexin-A (OXA) is a neuropeptide with neuroprotective effect by reducing cerebral ischemia/reperfusion injury (CIRI). Inflammation and apoptosis mediated by astrocyte activation are the key pathological mechanisms for CIRI. We thus attempted to confirm neuroprotective effects of OXA on astrocytic inflammation and apoptosis in CIRI and clarify the relative mechanisms. A middle cerebral artery occlusion and reperfusion (MCAO/R) rat model and U251 glioma cells model subjected to oxygen glucose deprivation and reperfusion (OGD/R) were established, with or without OXA treatment. Neurological deficit score was determined, and cerebral infarct volume was evaluated by 2,3,5-triphenyltetrazolium chloride (TTC) staining. Western Blot was used to detect the expressions of NF-κB p65, p-p65, p-ERK, p-p38, GFAP, OX1R, IL-1β, TNF-α, IL-6, iNOS, Bcl-2, Bax, CytC, cleaved caspase-9 and cleaved caspase-3 in vivo and in vitro. Pro-inflammatory cytokines in cell supernatant IL-1β, TNF-α and IL-6 were determined by ELISA. Hoechst 33342 staining was used to detect the apoptosis of astrocyte. Immunofluorescent staining was performed to assess the nuclear translocation of p65 and the expression of GFAP. The results showed that OXA significantly improved neurological deficit score and decreased the volume of infarct area in brain. OXA decreased inflammatory mediators, inhibited astrocyte activation and nuclear translocation of NF-κB and phosphorylation of NF-κB, MAPK/ERK and MAPK/p38. Besides, OXA suppressed apoptosis via upregulating the ratio of Bcl-2/Bax and downregulating cytochrome C, cleaved-caspase-9 and cleaved caspase-3. Overall, it was concluded that OXA exerts neuroprotective effect during CIRI through attenuating astrocytes apoptosis, astrocytes activation and pro-inflammatory cytokines production, by Inhibiting OX1R-mediated NF-κB, MAPK/ERK and MAPK/p38 signaling pathways. The progress in our study is helpful to elucidate the molecular mechanisms of OXA neuroprotection, which could lead to the development of new treatment strategies for ischemic stroke.

Dexmedetomidine post-conditioning attenuates cerebral ischemia following asphyxia cardiac arrest through down-regulation of apoptosis and neuroinflammation in rats

Background

Neuroprotection strategies after cardiac arrest (CA)/cardiopulmonary resuscitation (CPR) remain key areas of basic and clinical research. This study was designed to investigate the neuroprotective effects of dexmedetomidine following resuscitation and potential mechanisms.

Methods

Anesthetized rats underwent 6-min asphyxia-based cardiac arrest and resuscitation, after which the experimental group received a single intravenous dose of dexmedetomidine (25 μg/kg). Neurological outcomes and ataxia were assessed after the return of spontaneous circulation. The serum levels and brain expression of inflammation markers was examined, and apoptotic cells were quantified by TUNEL staining.

Results

Neuroprotection was enhanced by dexmedetomidine post-conditioning after the return of spontaneous circulation. This enhancement was characterized by the promotion of neurological function scores and coordination. In addition, dexmedetomidine post-conditioning attenuated the serum levels of the pro-inflammatory cytokine tumor necrosis factor (TNF)-α at 2 h, as well as interleukin IL-1β at 2, 24, and 48 h. TUNEL staining showed that the number of apoptotic cells in the dexmedetomidine post-conditioning group was significantly reduced compared with the control group. Further western blot analysis indicated that dexmedetomidine markedly reduced the levels of caspase-3 and nuclear factor-kappa B (NF-κB) in the brain.

Conclusions

Dexmedetomidine post-conditioning had a neuroprotective effect against cerebral injury following asphyxia-induced cardiac arrest. The mechanism was associated with the downregulation of apoptosis and neuroinflammation.

Electric Acupuncture Treatment Promotes Angiogenesis in Rats with Middle Cerebral Artery Occlusion Through EphB4/EphrinB2 Mediated Src/PI3K Signal Pathway

BACKGROUND

Cerebral infarction is one of the most common causes of disability and death worldwide. It is reported that electric acupuncture was able to improve the prognosis of cerebral infarction by promoting angiogenesis. However, the corresponding signal pathways of angiogenesis promotes by electric acupuncture treatment needs to be further explored.

METHODS

MCAO rat was employed as the animal model, and clopidogrel hydrogen sulfate treatment was set as the positive control. Behaviors of rats, H&E staining, and TTC-staining was used to evaluate the recovery of infarcted brain tissue and nervous function. After that, immunocytochemical and immunofluorescence staining was used to quantify the angiogenesis and compensatory circulation, which including the analysis of microvessel density, field/ microvessel area ratio, and microvessel diameter. Western blot and RT-PCR for the detection of the related signal molecule, PI3K, Src, and EphB4/ephrinB2.

RESULTS

The neurologic impairment scores were decreased, and the brain tissue damage that showed with H&E and TTC-staining was relieved by the treatment of electric acupuncture in MCAO rat. The quantification of microvessel density and field/ microvessel area ratio was improved obviously, and the microvessel diameter was decreased which represent the angiogenesis of capillary in day 3 and 7 by the electric acupuncture treatment. We also found that the level of Src and PI3K was increased markedly followed by the up-regulation of EphB4 and EphrinB2 mRNA during the electric acupuncture treatment, and the pre-treatment of Src and/or PI3K inhibitor was able to disturb the angiogenesis of capillary.

CONCLUSIONS

We proved that electric acupuncture was able to accelerate the recovery of infarcted brain tissue and nervous function in MCAO rat by the promotion of angiogenesis, which was regulated by EphB4/EphrinB2 mediated Src/PI3K signal pathway. Our study provides a potential therapy and theoretical basis for the clinical treatment of cerebral infarction by the use of electric acupuncture.

Electroacupuncture improves learning and memory functions in a rat cerebral ischemia/reperfusion injury model through PI3K/Akt signaling pathway activation

Electroacupuncture has been widely used to treat cognitive impairment after cerebral ischemia, but the underlying mechanism has not yet been fully elucidated. Studies have shown that autophagy plays an important role in the formation and development of cognitive impairment, and the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway plays an important role in autophagy regulation. To investigate the role played by the PI3K/Akt signaling pathway in the electroacupuncture treatment of cerebral ischemia/reperfusion rat models, we first established a rat model of cerebral ischemia/reperfusion through the occlusion of the middle cerebral artery using the suture method. Starting at 2 hours after modeling, electroacupuncture was delivered at the Shenting (GV24) and Baihui (GV20) acupoints, with a dilatational wave (1-20 Hz frequency, 2 mA intensity, 6 V peak voltage), for 30 minutes/day over 8 consecutive days. Our results showed that electroacupuncture reduced the infarct volume in a rat model of cerebral ischemia/reperfusion injury, increased the mRNA expression levels of the PI3K/Akt signaling pathway-related factors Beclin-1, mammalian target of rapamycin (mTOR), and PI3K, increased the protein expression levels of phosphorylated Akt, Beclin-1, PI3K, and mTOR in the ischemic cerebral cortex, and simultaneously reduced p53 mRNA and protein expression levels. In the Morris water maze test, the latency to find the hidden platform was significantly shortened among rats subjected to electroacupuncture stimulation compared with rats without electroacupuncture stimulation. In the spatial probe test, the number of times that a rat crossed the target quadrant was increased in rats subjected to electroacupuncture stimulation compared with rats without electroacupuncture stimulation. Electroacupuncture stimulation applied to the Shenting (GV24) and Baihui (GV20) acupoints activated the PI3K/Akt signaling pathway and improved rat learning and memory impairment. This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Henan University of Traditional Chinese Medicine, China (approval No. 8150150901) on March 10, 2016.

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 in the prevention and treatment of stroke: a review of foreign studies]

Acupuncture has been recommended by the World Health Organization (WHO) as an alternative and complementary method for treating stroke and a way to increase the effectiveness of rehabilitation. The data available in the literature suggest that acupuncture has a beneficial effect on the status of patients with stroke. The mechanism of action of acupuncture for stroke includes the following components: 1) stimulation of neurogenesis and cell proliferation in the CNS; 2) regulation of cerebral blood flow; 3) antiapoptosis; 4) regulation of neurotransmitters; 5) improvement of the neuronal synaptic function, stimulation of long-term potentiation; 6) stimulation of neuroplasticity; and 7) decrease in blood-brain barrier permeability. Acupuncture has been proven to have a positive impact on the restoration of stroke-related dysfunctions, such as motor disorders, spasticity, cognitive impairment, and dysphagia. The most commonly used acupuncture points for the treatment of motor disorders are GV20, GB20, LI4, ST36, SP6, LI11, GB39, and motor scalp area; those for the treatment of cognitive dysfunction are GV20 and EX-HN-1, and those for the treatment of dysphagia are GV20, GV16, and CV23. A review of the literature indicates that studies of the clinical potential of acupuncture in the treatment of complications and the prevention of stroke are insufficient. It is assumed that the international community's recent interest in acupuncture methods used in the treatment of stroke will lead to the emergence of new studies and publications.

Effect of Acupuncture on the p38 Signaling Pathway in Several Nervous System Diseases: A Systematic Review

Acupuncture is clinically used to treat various diseases and exerts positive local and systemic effects in several nervous system diseases. Advanced molecular and clinical studies have continually attempted to decipher the mechanisms underlying these effects of acupuncture. While a growing understanding of the pathophysiology underlying several nervous system diseases shows it to be related to inflammation and impair cell regeneration after ischemic events, the relationship between the therapeutic mechanism of acupuncture and the p38 MAPK signal pathway has yet to be elucidated. This review discusses the latest advancements in the identification of the effect of acupuncture on the p38 signaling pathway in several nervous system diseases. We electronically searched databases including PubMed, Embase, and the Cochrane Library from their inception to April 2020, using the following keywords alone or in various combinations: "acupuncture", "p38 MAPK pathway", "signaling", "stress response", "inflammation", "immune", "pain", "analgesic", "cerebral ischemic injury", "epilepsy", "Alzheimer's disease", "Parkinson's disease", "dementia", "degenerative", and "homeostasis". Manual acupuncture and electroacupuncture confer positive therapeutic effects by regulating proinflammatory cytokines, ion channels, scaffold proteins, and transcription factors including TRPV1/4, Nav, BDNF, and NADMR1; consequently, p38 regulates various phenomena including cell communication, remodeling, regeneration, and gene expression. In this review article, we found the most common acupoints for the relief of nervous system disorders including GV20, GV14, ST36, ST37, and LI4. Acupuncture exhibits dual regulatory functions of activating or inhibiting different p38 MAPK pathways, contributing to an overall improvement of clinical symptoms and function in several nervous system diseases.

Functional connectivity of the retrosplenial cortex in rats with ischemic stroke is improved by electroacupuncture

BACKGROUND

The aim of this study was to investigate the central mechanism underlying the putative beneficial effects of electroacupuncture (EA) on learning and memory ability of rats with ischemic stroke-induced cognitive deficits by resting-state functional magnetic resonance imaging (fMRI).

METHODS

A rat model of middle cerebral artery occlusion (MCAO)-induced cognitive deficit (MICD) was established. Rats were randomly assigned into a sham-operated control group (SC group, n = 12), untreated MICD model group (MICD group, n = 12), and MICD group receiving EA treatment at GV20 and GV24 (MICD + EA group, n = 12).

RESULTS

Compared to the MICD group, rats in the MICD + EA group receiving EA at GV20 and GV24 exhibited significantly shortened escape latency times and crossed the position of the platform a significantly increased number of times during the Morris water maze test on the 14th day after EA, which suggested EA could significantly improve spatial learning and memory ability. Furthermore, compared to the MICD group, functional connectivity of the left retrosplenial cortex (RSC) with the left hippocampus, left RSC, right RSC, left cingulate gyrus, right cingulate gyrus, right tegmentum of midbrain, and right visual cortex was increased in the MICD + EA group; the MICD group showed decreased functional connectivity of the left RSC with the left hippocampus, right hippocampus, left RSC, right RSC, right amygdaloid body, left visual cortex, and right visual cortex.

CONCLUSION

These findings suggest that EA at GV20 and GV24 might improve the learning and memory ability of MICD rats by increasing the functional connectivity between the RSC and hippocampus, cingulate gyrus and midbrain, which is encouraging for the potential treatment for cognitive impairment secondary to ischemia stroke.

Crosstalk between Acupuncture and NF-κB in Inflammatory Diseases

Acupuncture has been used in China for thousands of years and concerned as a typical alternative medicine in inflammatory diseases nowadays. The nuclear factor-κB (NF-κB) transcription factor is an important regulator of inflammation. In this article, we discuss the role of acupuncture in NF-κB pathways and also present the acupoints selection, acupuncture administration, and related inflammation diseases and models from previous studies to bring readers close to a more complete understanding of the mechanisms between acupuncture and NF-κB in inflammatory diseases.

Effects of CXCR7-neutralizing antibody on neurogenesis in the hippocampal dentate gyrus and cognitive function in the chronic phase of cerebral ischemia

Stromal cell-derived factor-1 and its receptor CXCR4 are essential regulators of the neurogenesis that occurs in the adult hippocampal dentate gyrus. However, the effects of CXCR7, a new atypical receptor of stromal cell-derived factor-1, on hippocampal neurogenesis after a stroke remain largely unknown. Our study is the first to investigate the effect of a CXCR7-neutralizing antibody on neurogenesis in the dentate gyrus and the associated recovery of cognitive function of rats in the chronic stage of cerebral ischemia. The rats were randomly divided into sham, sham + anti-CXCR7, ischemia and ischemia + anti-CXCR7 groups. Endothelin-1 was injected in the ipsilateral motor cortex and striatum to induce focal cerebral ischemia. Sham group rats were injected with saline instead of endothelin-1 via intracranial injection. Both sham and ischemic rats were treated with intraventricular infusions of CXCR7-neutralizing antibodies for 6 days 1 week after surgery. Immunofluorescence staining with doublecortin, a marker for neuronal precursors, was performed to assess the neurogenesis in the dentate gyrus. We found that anti-CXCR7 antibody infusion enhanced the proliferation and dendritic development of doublecortin-labeled cells in the dentate gyrus in both ischemic and sham-operated rats. Spatial learning and memory functions were assessed by Morris water maze tests 30–32 days after ischemia. CXCR7-neutralizing antibody treatment significantly reduced the escape latency of the spatial navigation trial and increased the time spent in the target quadrant of spatial probe trial in animals that received ischemic insult, but not in sham operated rats. These results suggest that CXCR7-neutralizing antibody enhances the neurogenesis in the dentate gyrus and improves the cognitive function after cerebral ischemia in rats. All animal experimental protocols and procedures were approved by the Institutional Animal Care and Use Committee of China Medical University (CMU16089R) on December 8, 2016.

Ginkgetin attenuates cerebral ischemia-reperfusion induced autophagy and cell death via modulation of the NF-κB/p53 signaling pathway

Background: Cerebral ischemia–reperfusion (I/R) injury is the key to fatality in cerebrovascular accident, hence further endeavor is warranted to delineate the mechanism underlying its lethal aggravation procedure. In the present study, we aimed to elucidate the anti-autophagy and anti-apoptosis effects of ginkgetin via nuclear factor κB (NF-κB)/p53 pathway in cerebral I/R rats.

Methods: Rats were administrated 2-h occlusion of right middle cerebral artery before the 24-h reperfusion followed. There were three doses of ginkgetin (25, 50, 100 mg/kg) given intraperitoneally (i.p.) after the 2-h ischemia, and Pifithrin-α (PFT-α, p53 inhibitor), SN50 (NF-κB inhibitor) and 3-methyladenine (3-MA, autophagy inhibitor) was administered 20 min before the ischemia, respectively.

Results: The neurological deficits decreased significantly with the administration of ginkgetin. The concentrations of microtubule-associated protein 1 light chain 3-II and p53 were significantly decreased by PFT-α, 3-MA and ginkgetin. The concentrations of Beclin 1, damage-regulated autophagy modulator, cathepsin B and cathepsin D were significantly decreased due to the administration of PFT-α, ginkgetin and SN50. Furthermore, the concentrations of Bax and p53-upregulated modulator of apoptosis were significantly decreased with that of Bcl-2 being significantly increased by administration of SN50, PFT-α and ginkgetin.

Conclusion: Ginkgetin can alleviate cerebral ischemia/reperfusion induced autophagy and apoptosis by inhibiting the NF-κB/p53 signaling pathway.

Signal Transduction Pathways of Acupuncture for Treating Some Nervous System Diseases

In this article, we review signal transduction pathways through which acupuncture treats nervous system diseases. We electronically searched the databases, including PubMed, MEDLINE, clinical Key, the Cochrane Library, and the China National Knowledge Infrastructure from their inception to December 2018 using the following MeSH headings and keywords alone or in varied combination: acupuncture, molecular, signal transduction, genetic, cerebral ischemic injury, cerebral hemorrhagic injury, stroke, epilepsy, seizure, depression, Alzheimer's disease, dementia, vascular dementia, and Parkinson's disease. Acupuncture treats nervous system diseases by increasing the brain-derived neurotrophic factor level and involves multiple signal pathways, including p38 MAPKs, Raf/MAPK/ERK 1/2, TLR4/ERK, PI3K/AKT, AC/cAMP/PKA, ASK1-JNK/p38, and downstream CREB, JNK, m-TOR, NF-κB, and Bcl-2/Bax balance. Acupuncture affects synaptic plasticity, causes an increase in neurotrophic factors, and results in neuroprotection, cell proliferation, antiapoptosis, antioxidant activity, anti-inflammation, and maintenance of the blood-brain barrier.

Acupuncture attenuates cognitive impairment, oxidative stress and NF-κB activation in cerebral multi-infarct rats

BACKGROUD

Patients with multiple infarct dementia (MID) have subtle deficits that commonly go unnoticed, and are at risk of developing Alzheimer's disease. Oxidative stress induced by ischaemic injury results in intracellular calcium accumulation and neuronal apoptosis, leading to cognitive impairment by triggering various cellular signal transduction pathways. Several studies have suggested that NF-κB in the presence of p53 has a pro-apoptotic function in various models, but the mechanism is unclear.

AIMS

The aim of this study was to investigate whether acupuncture could protect cognitive function against cerebral multi-infarction (CMi) induced oxidative stress by inhibiting the activation of NF-κB and its target gene p53.

METHODS

An animal model of CMi was established by injecting homologous blood emboli into the right internal carotid artery of male Wistar rats. After 2 weeks of acupuncture treatment, cognitive function was detected by novel object recognition. Electron spin resonance and Fluo-3 fuorescence imaging were used to test the generation of ROS and intracellular calcium accumulation, respectively. Expression of NF-κB and p53 was examined by Western blot analysis and immunofluorescence.

RESULTS

CMi induced spatial learning and memory impairment, overproduction of intracellular hydroxyl radicals, and elevations of Ca²⁺, which were ameliorated by verum acupuncture treatment. Acupuncture inhibited activation of NF-κB and its downstream target gene p53.

CONCLUSION

These findings suggest that acupuncture could protect cognitive function against oxidative stress induced by CMi, which is partially associated with suppression of NF-κB-p53 activation.

Neuroprotection of cordycepin in NMDA-induced excitotoxicity by modulating adenosine A1 receptors

Cerebral ischemia impairs physiological form of synaptic plasticity such as long-term potentiation (LTP). Clinical symptoms of cognitive dysfunction resulting from cerebral ischemia are associated with neuron loss and synaptic function impairment in hippocampus. It has been widely reported that cordycepin displays neuroprotective effect on ameliorating cognitive dysfunction induced by cerebral ischemia. Therefore, it is necessary to study whether cordycepin recovers cognitive function after brain ischemia through improving LTP induction. However, there has been very little discussion about the effects of cordycepin on LTP of cerebral ischemia so far. In the present study, we investigated the effects of cordycepin on LTP impairment and neuron loss induced by cerebral ischemia and excitotoxicity, using electrophysiological recording and Nissl staining techniques. The models were obtained by bilateral common carotid artery occlusion (BCCAO) and intrahippocampal NMDA microinjection. We also explored whether adenosine A₁ receptors involve in the neuroprotection of cordycepin by using western blot. We found that cordycepin remarkably alleviated LTP impairment and protected pyramidal cell of hippocampal CA1 region against cerebral ischemia and excitotoxicity. Meanwhile, cordycepin prevented the reduction on adenosine A₁ receptor level caused by ischemia but did not alter the adenosine A_2A receptor level in hippocampal CA1 area. The improvement of LTP in the excitotoxic rats after cordycepin treatment could be blocked by DPCPX, a selective antagonist of adenosine A₁ receptor. In summary, our findings provided new insights into the mechanisms of cordycepin neuroprotection in excitotoxic diseases, which is through regulating adenosine A₁ receptor to improve LTP formation and neuronal survival.

Mechanisms Involved in the Neuroprotection of Electroacupuncture Therapy for Ischemic Stroke

Stroke is one of the main causes of death all over the world. As the combination of acupuncture and electric stimulation, electroacupuncutre is a safe and effective therapy, which is commonly applied in ischemic stroke therapy in both experimental studies and clinical settings. The review was performed via searching for related articles in the databases of OVID, PUBMED, and ISI Web of Science from their respective inceptions to May 2018. In this review, we summarized the mechanism of EA for ischemic stroke via a series of factors, consisting of apoptosis related-factors, inflammatory factors, autophagy-related factors, growth factors, transcriptional factors, cannabinoid CB1 receptors, and other factors. In summary, EA stimulation may effectively alleviate ischemic brain injury via a series of signal pathways and various other factors.

Combined Effects of Electroacupuncture and Behavioral Training on Learning-Memory Ability and Event-Related Potential P300 in Rats with Mid/Advanced Cerebral Infarction

Background:

The effectiveness of the combination of electroacupuncture (EA) and behavioral training (BT) for mid/advanced cerebral infarction (M/ACI) and related mechanisms remains unclear. This study aimed to investigate the combined effects on the learning-memory ability and event-related potential P300 in rats with M/ACI.

Methods:

Eighty rats with M/ACI were divided into Group Model (M), Group EA, Group BT, and Group EA-BT (n = 20) according to the random number with five healthy rats in Group Control (CON). On the 6^th week after modeling, EA, BT, and EA-BT were given to Group EA, Group BT, and Group EA-BT, respectively, whereas Group M and Group CON were not given any intervention. Y-maze test and P300 were recorded before and after the intervention.

Results:

After intervention, the P300 latency was lower and the amplitude was higher in the Group EA-BT, Group EA, and Group BT than before (for latency, t = −7.638, −4.334, and −5.916; for amplitude, t = 8.125, 3.846, and 5.238; P < 0.01), with Group EA-BT superior to Group EA (for latency, t = −3.708; for amplitude, t = 3.653; P < 0.01) and Group BT (for latency, t = −2.067; for amplitude, t = 2.816; P < 0.05), with no significant difference between Group BT and EA (for latency, t = −1.439; for amplitude, t = 1.075; P > 0.05). While the performances of Y-maze tests in the Group EA-BT, Group EA, and Group BT were all better than before (t = 10.359, 4.520, and 7.791, P < 0.01), with Group EA-BT better than Group EA (t = 5.627, P < 0.01) and Group BT (t = 2.913, P < 0.01) respectively, and Group BT better than Group EA (t = 2.912, P < 0.01).

Conclusion:

EA or BT can affect P300 in rats with M/ACI, and the combination of these two methods can significantly improve the learning-memory ability.

Preclinical Evidence and Mechanism of Xingnaojing Injection for Cerebral Ischemia: A Systematic Review and Meta-Analysis of Animal Studies

Objectives

Cerebral ischemia can cause severe harm to people's health with the characteristics of high incidence, high disability, and high mortality. Xingnaojing injection (XNJI) is widely used in the treatment of cerebral ischemia. The aim of this review is to evaluate the efficacy and mechanism of XNJI in animal models of cerebral ischemia.

Methods

Total seven electronic databases in English or Chinese (CNKI, Wanfang, VMIS, PubMed, MEDLINE, Embase, and the Cochrane Library) about most experiments and studies which came out before June 2018 of XNJI for cerebral ischemia have been searched. Data extraction, quality assessment, and meta-analysis are conducted according to the Cochrane standards and RevMan 5.3 software.

Results

We have identified 23 eligible studies and made a meta-analysis based on these studies. Meta-analysis shows that XNJI contributes significantly to reduction in neurological deficit score (P = 0.0002, MD = −1.25, 95% CI: −1.92, −0.58) compared with the control group of cerebral ischemia. Subgroup analytic results demonstrate that XNJI has been more effective in animal model of cerebral ischemia-reperfusion injury (P = 0.009, MD = −1.35, 95%CI: −2.36, −0.34) than that of permanent cerebral ischemia (P = 0.0002, MD = −1.08, 95%CI: −1.66, −0.51). Compared with control group, XNJI could remarkably reduce cerebral infarction area (P < 0.00001, MD = −14.98, 95%CI: −21.36, −8.59), brain edema (P < 0.00001, MD = −4.64, 95%CI: −5.38, −3.90), and neuronal cell apoptosis (P < 0.0001, MD = −12.21, 95%CI: 18.05, −6.37). Meanwhile, the meta-analysis shows that XNJI has a significant anti-inflammatory effect, and the levels of TNF-α, IL-6, and IL-1β are significantly reduced by XNJI (P = 0.001, MD = −4.13, 95%CI:−6.68, −1.58; P < 0.00001, MD = −119.23, 95%CI: −138.04, −100.43; P = 0.21, MD = −228.69, 95% CI: −586.20, 128.83). Additionally, XNJI could raise the body's antioxidant function and the level of SOD and GSH-Px (P = 0.002, MD = 53.02, 95% CI: −20.52, 85.78; P = 0.01, MD = 8.65, 95% CI: 1.77, 15.48) and decrease the level of MDA (P < 0.00001, MD = −4.16, 95% CI: −5.50, −2.82).

Conclusion

XNJI might be effective in cerebral ischemia by regulating oxidative stress and inflammatory reaction.

Electroacupuncture stimulates the proliferation and differentiation of endogenous neural stem cells in a rat model of ischemic stroke

Electroacupuncture (EA) may stimulate neurogenesis in animal models of ischemic stroke; however, the associated mechanisms are not clear. The present study aimed to evaluate the neurogenesis efficacy of EA on ischemic stroke and the underlying associated mechanisms. A model of middle cerebral artery occlusion (MCAO) was employed as the rat model of brain ischemia and reperfusion. EA treatment at the GV20 (Baihui) and GV14 (Dazhui) acupoints was conducted for 30 min daily following MCAO. Immunofluorescence was performed to measure the number of bromodeoxyuridine (BrdU)/nestin- or BrdU/doublecortin (DCX)-positive cells in the sham, MCAO and MCAO + EA groups. Results indicated that EA stimulation significantly decreased the neurological score and neuronal loss in rats in the MCAO group (both P<0.05). Furthermore, immunostaining assays indicated that BrdU/nestin- and BrdU/DCX-positive cells in EA-treated rats were significantly increased (P<0.05) when compared with the rats in the MCAO group, indicating EA may induce the proliferation and differentiation of endogenous neural stem cells (eNSCs) during cerebral ischemia-reperfusion. In addition, EA treatment significantly enhanced the protein expression levels of plasticity-related gene 5 (PRG5), a critical neurogenesis factor, and significantly decreased the protein expression levels of three neurogenesis inhibiting molecules, NogoA, lysophosphatidic acid and RhoA (all P<0.05). These results suggested that EA promotes the proliferation and differentiation of eNSCs, likely through modulating PRG5/RhoA signaling.

Electroacupuncture ameliorates cognitive impairment through inhibition of Ca2+-mediated neurotoxicity in a rat model of cerebral ischaemia-reperfusion injury

Background

The hippocampus is vulnerable to severe damage after cerebral ischaemia–reperfusion (I/R) injury. This study aimed to explore the effect of electroacupuncture (EA) on cognitive impairment and its relationship with Ca²⁺neurotoxicity in a rat model of I/R injury induced by middle cerebral artery occlusion (MCAO).

Methods

60 adult male Sprague-Dawley rats were randomly divided into three groups: control (sham surgery) group, untreated MCAO group and EA-treated MCAO+EA group. Rats in the MCAO and MCAO+EA groups underwent modelling of poststroke cognitive impairment by MCAO surgery. EA was performed for 30 min daily at GV20 and GV24 (1–20 Hz) for 1 week. The Morris water maze experiment was used to assess cognitive function. 2,3,5-triphenyl tetrazolium chloride staining was used to measure infarct volume. The intracellular Ca²⁺content in the Cornu Ammonis (CA)1 area of the hippocampus was assessed by laser confocal scanning microscopy. ELISA was performed to evaluate the concentration of glutamate (Glu) in the hippocampus, and the protein expression of two Glu receptors (N-methyl-D-aspartic acid receptor (NMDAR) 2A and NMDAR2B) were analysed by Western blotting.

Results

Compared with the untreated MCAO group, EA effectively ameliorated cognitive impairment (P=0.01) and shrunk the infarct volume (P=0.032). The content of intracellular Ca²⁺, Glu and NMDAR2B in the hippocampus was significantly raised by MCAO (P=0.031-0.043), while EA abrogated these effects. NMDAR2A was decreased by MCAO (P=0.015) but increased by EA (P=0.033).

Conclusions

EA had a beneficial effect on cognitive repair after cerebral I/R, and its mechanism of action likely involves a reduction of Ca²⁺influx via inhibition of Glu neurotoxicity and downregulation of NMDAR2B expression.

Microglia TREM2 is required for electroacupuncture to attenuate neuroinflammation in focal cerebral ischemia/reperfusion rats

Neuroinflammation plays a critical role in ischemic stroke pathology and could be a promising target in ischemic stroke. Triggering receptor expressed on myeloid cells 2 (TREM2) is a microglia-specific receptor in the CNS that is involved in regulating neuroinflammation in cerebral ischemia. However, the role of TREM2 in ischemic stroke is controversial. Electroacupuncture (EA) is an effective therapy for alleviating stroke-induced neuroinflammation. Here, we found that ischemic stroke induced an increased microglial TREM2 expression, and EA treatment can further promote microglial TREM2 expression following cerebral ischemia. TREM2 overexpression was observed to play a neuroprotective role by improving the neurobehavioral deficit and reducing the cerebral infarct volume 72 h after reperfusion, whereas TREM2 silencing had the opposite effects. Moreover, the effects of EA on improving stroke outcome and suppressing neuroinflammation in the brain were reversed by TREM2 silencing. Finally, TREM2 silencing also suppressed the ability of EA to regulate the PI3K/Akt and NF-κB signaling pathways. Altogether, the results show that TREM2 could be a potential target in EA treatment for attenuating inflammatory injury following cerebral ischemia/reperfusion.

Possible Involvement of PTEN Signaling Pathway in the Anti-apoptotic Effect of Electroacupuncture Following Ischemic Stroke in Rats

As a traditional therapeutic method, electroacupuncture (EA) has been adopted as an alternative therapy for stroke recovery. Here, we aimed to evaluate whether EA therapy at points of Quchi (LI11) and Zusanli (ST36) alleviated neuronal apoptosis by PTEN signaling pathway after ischemic stroke. A total of 72 male Sprague-Dawley rats were randomized into three groups, including sham group, MCAO group, and EA group. EA was initiated after 24 h of reperfusion for 3 consecutive days. At 72 h following ischemia/reperfusion, neurological deficits, infarct volumes, and TUNEL staining were evaluated and the PTEN pathway-related proteins together with apoptosis-related proteins were detected. The results indicated that EA treatment significantly decreased cerebral infarct volume, neurological deficits and alleviated proportion of apoptotic cells in cerebral ischemic rats. Furthermore, EA significantly up-regulated the phosphorylation levels of PDK1, Akt(Thr308), GSK-3β, and down-regulated the phosphorylation levels of PTEN, Akt(Ser473) in the peri-infarct cortex. EA treatment significantly reduced the up-regulation of caspase-3, cleaved-caspase-3, Bim, and reversed the reduction of Bcl-2 induced by the ischemic stroke. These findings suggest that EA treatment at points of Quchi (LI11)- and Zusanli (ST36)-induced neuroprotection might involve inhibition of apoptosis via PTEN pathway.

Electroacupuncture Alleviated Neuronal Apoptosis Following Ischemic Stroke in Rats via Midkine and ERK/JNK/p38 Signaling Pathway

This study aimed to evaluate the effects of electroacupuncture (EA) intervention administered at rats of middle cerebral artery occlusion (MCAO)/reperfusion. Fifty-four male Sprague-Dawley rats were divided into three groups, consisting of sham group, MCAO/R group, and EA group. EA treatment at Quchi and Zusanli acupoints was applied in rats of EA group at 24 h after MCAO once per day for 3 days. Our results indicated that EA treatment reduced infarct volumes and neurological deficits, as well alleviated the apoptotic cells in peri-infarct cortex, indicating that EA exerted neuroprotective effect in cerebral ischemic rats. Moreover, EA treatment may effectively reverse the upregulation of caspase-3 and Bim and alleviate the inhibition of Bcl-2 following 72-h ischemic stroke. EA may significantly reverse the promoted relative density level of p-ERK1/2, p-JNK, and p-p38 in the EA group compared with the MCAO/R group. In addition, the growth factor midkine (MK) was upregulated at 72 h after MCAO/R, and EA treatment may significantly prompt expression of MK. Our study demonstrated that EA exerted neuroprotective effect against neuronal apoptosis and the mechanism might involve in upregulation of MK and mediation of ERK/JNK/p38 signal pathway.

Electroacupuncture Ameliorates Cognitive Impairment and Spontaneous Low-Frequency Brain Activity in Rats with Ischemic Stroke

BACKGROUND

To evaluate whether electroacupuncture (EA) at Baihui (DU20) and Shenting (DU24) acupoints could improve cognitive function and enhance spontaneous low-frequency brain activity in rats with ischemic stroke.

METHODS

Total 36 rats were randomly divided into 3 groups-the sham surgery (Sham) group, the middle cerebral artery occlusion induced cognitive deficit (MICD) group, and the MICD with EA (MICD + EA) treatment group. The rats in MICD + EA group received EA treatment at DU20 and DU24 acupoints for 14 consecutive days after the surgery. The Morris water maze test was performed to assess the spatial learning and memory ability of the rats. Magnetic resonance imaging (MRI) was used to investigate the infarction volume and spontaneous low-frequency brain activity of each group.

RESULTS

After EA for 14 days, the learning and memory ability of the MICD rats was improved, and the brain infarction volume was reduced. Furthermore, basing on the fMRI amplitude of low-frequency fluctuation (ALFF) analysis, the decreased ALFF of the MICD rats was found in auditory cortex, cingulate gyrus, lateral nucleus group of dorsal thalamus, hippocampus, motor cortex, prelimbic cortex, retrosplenial cortex, and sensory cortex compared with the rats in sham group. However, these suppressive regions were notably attenuated after EA treatment.

CONCLUSIONS

Our results suggested that EA at DU20 and DU24 acupoints could ameliorate cognitive impairment in rats with ischemic stroke, and the protective effect of EA may attribute to reactivating the cognition-related brain regions, such as hippocampus, retrosplenial cortex, cingulate gyrus, prelimbic cortex, and sensory cortex.

Electroacupuncture Inhibits Apoptosis of Peri-Ischemic Regions via Modulating p38, Extracellular Signal-Regulated Kinase (ERK1/2), and c-Jun N Terminal Kinases (JNK) in Cerebral Ischemia-Reperfusion-Injured Rats

BACKGROUND Previous studies suggested that inhibition of apoptosis prevents the dysfunction of ischemia-reperfusion injury. In the pathogenesis of ischemia-reperfusion injury, JNK/ERK1/2 and p38 play an essential role in regulation of cell apoptosis. Electroacupuncture (EA), a form of acupuncture, has demonstrated superiority in preventing ischemia-reperfusion injury, but the underlying mechanism is unclear. In the present study, we explored the effects of electroacupuncture at Shenting (GV24) and Baihui (GV20) acupoints on focal cerebral ischemia-reperfusion (MCAO) rats, and explored whether JNK/ERK1/2- and p38-mediated cell apoptosis are involved. MATERIAL AND METHODS The rats were divided into a sham operation control group, an ischemia group, and an electroacupuncture group with acupuncture applied for 10 days (30 min per day). TTC staining was used to calculate the ischemic brain volume. TUNEL staining and transmission electron microscopy were used to detect cell apoptosis. Western blot analysis and Bio-Plex were used to detect JNK, p38, ERK1/2, Bcl-2, and Bax protein expression. RESULTS We found that electroacupuncture at day 10 significantly reduced cerebral infarction. In addition, electroacupuncture suppressed activation of JNK and p38, while enhancing the activation of ERK1/2 in the peri-ischemic regions. Consequently, the effect of electroacupuncture on these pathways resulted in the inhibition of apoptosis, which was demonstrated by TUNEL and transmission electron microscopy. We found that electroacupuncture upregulated the anti-apoptotic Bcl-2/Bax ratio in peri-ischemic regions. CONCLUSIONS Our findings suggest that inhibition of cell apoptosis via regulating multiple signaling pathways might be a mechanism whereby electroacupuncture has a positive therapeutic effect on post-stroke impairment.

Catgut implantation at acupoints increases the expression of glutamate aspartate transporter and glial glutamate transporter-1 in the brain of rats with spasticity after stroke

Catgut implantation at acupoints has been shown to alleviate spasticity after stroke in rats. However, the underlying mechanisms are poorly understood. In this study, we used the rat middle cerebral artery occlusion model of stroke. Three days after surgery, absorbable surgical catgut sutures were implanted at Dazhui (GV14), Jizhong (GV6), Houhui, Guanyuan (CV4) and Zhongwan (CV12). The Zea Longa score was used to assess neurological function. The Modified Ashworth Scale was used to evaluate muscle tension. The 2,3,5-triphenyl-tetrazolium chloride assay was used to measure infarct volume. Immunohistochemical staining was performed for glutamate aspartate transporter (GLAST) and glial glutamate transporter-1 (GLT-1) expression. Western blot assay was used to analyze the expression of GLAST and GLT-1. Reverse transcription and polymerase chain reaction were carried out to assess the expression of GLAST and GLT-1 mRNAs. After catgut implantation at the acupoints, neurological function was substantially improved, muscle tension was decreased, and infarct volume was reduced in rats with spasticity after stroke. Furthermore, the expression of GLAST and GLT-1 mRNAs was increased on the injured (left) side. Our findings demonstrate that catgut implantation at acupoints alleviates spasticity after stroke, likely by increasing the expression of GLAST and GLT-1.

Modulation of Acupuncture on Cell Apoptosis and Autophagy

Acupuncture has been historically practiced to treat medical disorders by mechanically stimulating specific acupoints. Despite its well-documented efficacy, its biological basis largely remains elusive. Recent studies suggested that cell apoptosis and autophagy might play key roles in acupuncture therapy. Therefore, we searched PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI), aiming to find the potential relationship between acupuncture and cell apoptosis and autophagy. To provide readers with objective evidence, some problems regarding the design method, acupoints selection, acupuncture intervention measure, and related diseases existing in 40 related researches were shown in this review. These findings demonstrated that acupuncture has a potential role in modulating cell apoptosis and autophagy in animal models, suggesting it as a candidate mechanism in acupuncture therapy to maintain physiologic homeostasis.

Neurochemical changes in the hippocampus and prefrontal cortex associated with electroacupuncture for learning and memory impairment

Electroacupuncture (EA) has been widely used to treat cognitive impairment following cerebral ischemia. However, the functional mechanisms of EA have not been fully elucidated. The aim of the present study was to investigate whether EA at the GV 20 and DU 24 acupoints can improve the learning and memory ability via alteration of the neurochemical metabolism in the hippocampus (HPC) and prefrontal cortex (PFC) of rats with ischemia and reperfusion (I/R) injury. Sprague-Dawley male rats were randomly divided into three groups, namely the sham group (n=12), the middle cerebral artery occlusion (MCAO) group (n=12) and the EA treatment (MCAO + EA) group (n=12). MCAO was performed to establish the left focal cerebral I/R injury model, and the GV 20 and DU 24 acupoints were then stimulated with EA for 30 min per time, once daily, for 7 consecutive days. The Morris water maze (MWM) test was used to assess learning and memory ability. T2-weighted imaging was used to assess the cerebral infarct volume. Magnetic resonance spectroscopy was used to assess neurochemical metabolism of HPC and PFC. The neurological scores of the MCAO + EA group were significantly reduced compared with those of the MCAO group 7 days after EA treatment (P<0.01). The escape latency of the MWM test in the MCAO + EA group was found to be shorter compared with that in the MCAO group (P<0.01). The number of rats crossing through the platform area was significantly higher in the MCAO + EA group compared with that in the MCAO group (P<0.01). The cerebral infarct volume was also decreased in the MCAO + EA group compared with the MCAO group (P<0.05). The ratios of N-acetylaspartate (NAA)/creatine (Cr) and choline (Cho)/Cr of left-to-right HPC were increased in the MCAO + EA group compared with the MCAO group; however, the ratio of glutamate (Glu)/Cr did not change significantly (P>0.05). The ratios of NAA/Cr, Cho/Cr and Glu/Cr of left-to-right PFC were elevated (P<0.05). In conclusion, EA at the GV 20 and DU 24 acupoints may ameliorate learning and memory ability, possibly through increasing the levels of NAA and Cho in the HPC and PFC of rats with I/R injury.

Mechanisms of Acupuncture Therapy in Ischemic Stroke Rehabilitation: A Literature Review of Basic Studies

Acupuncture is recommended by the World Health Organization (WHO) as an alternative and complementary strategy for stroke treatment and for improving stroke care. Clinical trial and meta-analysis findings have demonstrated the efficacy of acupuncture in improving balance function, reducing spasticity, and increasing muscle strength and general well-being post-stroke. The mechanisms underlying the beneficial effects of acupuncture in stroke rehabilitation remain unclear. The aim of this study was to conduct a literature review, summarize the current known mechanisms in ischemic stroke rehabilitation through acupuncture and electroacupuncture (EA) therapy, and to detail the frequently used acupoints implicated in these effects. The evidence in this review indicates that five major different mechanisms are involved in the beneficial effects of acupuncture/EA on ischemic stroke rehabilitation: (1) Promotion of neurogenesis and cell proliferation in the central nervous system (CNS); (2) Regulation of cerebral blood flow in the ischemic area; (3) Anti-apoptosis in the ischemic area; (4) Regulation of neurochemicals; and, (5) Improvement of impaired long-term potentiation (LTP) and memory after stroke. The most frequently used acupoints in basic studies include Baihui (GV20), Zusanli (ST36), Quchi (LI11), Shuigou (GV26), Dazhui (GV14), and Hegu (LI4). Our findings show that acupuncture exerts a beneficial effect on ischemic stroke through modulation of different mechanisms originating in the CNS.

Electroacupuncture ameliorating post-stroke cognitive impairments via inhibition of peri-infarct astroglial and microglial/macrophage P2 purinoceptors-mediated neuroinflammation and hyperplasia

Background

During ischemic stroke (IS), adenosine 5′-triphosphate (ATP) is released from damaged nerve cells of the infract core region to the extracellular space, invoking peri-infarct glial cellular P2 purinoceptors singling, and causing pro-inflammatory cytokine secretion, which is likely to initiate or aggravate motor and cognitive impairment. It has been proved that electroacupuncture (EA) is an effective and safe strategy used in anti-inflammation. However, EA for the role of purine receptors in the central nervous system has not yet been reported.

Methods

Ischemia-reperfusion injured rat model was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). EA treatment at the DU 20 and DU 24 acupoints treatment were conducted to rats from the 12 h after MCAO/R injury for consecutive 7 days. The neurological outcomes, infarction volumes and the level of astroglial and microglial/macrophage hyperplasia, inflammatory cytokine and P2X7R and P2Y1R expression in the peri-infarct hippocampal CA1and sensorimotor cortex were investigated after IS to evaluate the MCAO/R model and therapeutic mechanism of EA treatment.

Results

EA effectively reduced the level of pro-inflammatory cytokine interleukin-1β (IL-1β) as evidenced by reduction in astroglial and microglial/macrophage hyperplasia and the levels of P2X7R and ED1, P2X7R and GFAP, P2Y1R and ED1, P2Y1R and GFAP co-expression in peri-infarct hippocampal CA1 and sensorimotor cortex compared with that of MCAO/R model and Non-EA treatment, accompanied by the improved neurological deficit and the motor and memory impairment outcomes. Therefore, our data support the hypothesis that EA could exert its anti-inflammatory effect via inhibiting the astroglial and microglial/macrophage P2 purinoceptors (P2X7R and P2Y1R)-mediated neuroinflammation after MCAO/R injury.

Conclusion

Astroglial and microglial/macrophage P2 purinoceptors-mediated neuroinflammation and hyperplasia in peri-infarct hippocampal CA1 and sensorimotor cortex were attenuated by EA treatment after ischemic stroke accompanied by the improved motor and memory behavior performance.

Electronic supplementary material

The online version of this article (10.1186/s12906-017-1974-y) contains supplementary material, which is available to authorized users.

Ferulic acid exerts neuroprotective effects against cerebral ischemia/reperfusion-induced injury via antioxidant and anti-apoptotic mechanisms in vitro and in vivo

Ferulic acid (FA) is a derivative of cinnamic acid. It is used in the treatment of heart head blood-vessel disease and exerts protective effects against hypoxia/ischemia-induced cell injury in the brain. This study investigated the potential neuroprotective effects of FA against ischemia/reperfusion (I/R)-induced brain injury in vivo and in vitro through hematoxylin and eosin (H&E) and Nissl staining assays, flow cytometry, Hoechst 33258 staining, quantitative PCR, western blot analysis and fluorescence microscopic analysis. In this study, models of cerebral I/R injury were established using rats and pheochromocytoma (PC-12) cells. The results revealed that treatment with FA significantly attenuated memory impairment, and reduced hippocampal neuronal apoptosis and oxidative stress in a dose-dependent manner. The results from in vitro experiments also indicated that FA protected the PC-12 cells against I/R-induced reactive oxygen species (ROS) generation and apoptosis by inhibiting apoptosis, Ca2+ influx, superoxide anion (O2-), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) production in a concentration-dependent manner. Moreover, FA inactivated the Toll-like receptor (TLR)/myeloid differentiation factor 88 (MyD88) pathway. MyD88 overexpression abolished the neuroprotective effects of FA. On the whole, we found that FA attenuated memory dysfunction and exerted protective effects against oxidative stress and apoptosis induced by I/R injury by inhibiting the TLR4/MyD88 signaling pathway. This study supports the view that FA may be a promising neuroprotective agent for use in the treatment of cerebral ischemia.

Repetitive Transcranial Magnetic Stimulation Ameliorates Cognitive Impairment by Enhancing Neurogenesis and Suppressing Apoptosis in the Hippocampus in Rats with Ischemic Stroke

Cognitive impairment is a serious mental deficit caused by stroke that can severely affect the quality of a survivor's life. Repetitive transcranial magnetic stimulation (rTMS) is a well-known rehabilitation modality that has been reported to exert neuroprotective effects after cerebral ischemic injury. In the present study, we evaluated the therapeutic efficacy of rTMS against post-stroke cognitive impairment (PSCI) and investigated the mechanisms underlying its effects in a middle cerebral artery occlusion (MCAO) rat model. The results showed that rTMS ameliorated cognitive deficits and tended to reduce the sizes of cerebral lesions. In addition, rTMS significantly improved cognitive function via a mechanism involving increased neurogenesis and decreased apoptosis in the ipsilateral hippocampus. Moreover, brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase B (TrkB), were clearly upregulated in ischemic hippocampi after treatment with rTMS. Additionally, further studies demonstrated that rTMS markedly enhanced the expression of the apoptosis-related B cell lymphoma/leukemia gene 2 (Bcl-2) and decreased the expression of the Bcl-2-associated protein X (Bax) and the number of TUNEL-positive cells in the ischemic hippocampus. Both protein levels and mRNA levels were investigated. Our findings suggest that after ischemic stroke, treatment with rTMS promoted the functional recovery of cognitive impairments by inhibiting apoptosis and enhancing neurogenesis in the hippocampus and that this mechanism might be mediated by the BDNF signaling pathway.