Effects of Electroacupuncture on Chronic Unpredictable Mild Stress Rats Depression-Like Behavior and Expression of p-ERK/ERK and p-P38/P38

Ginsenoside Rh2 administration produces crucial antidepressant-like effects in a CUMS-induced mice model of depression

INTRODUCTION

The most striking feature of depression is sadness and a loss of interest in activities, which represents a major cause of disability globally. Therefore, it is necessary to identify novel antidepressants for clinical practice. Ginsenoside Rh2 (Rh2) is one of the major bioactive ginsenosides that can be extracted from Panax ginseng and has been demonstrated to improve both memory and learning. The purpose of this study was to provide broad insight into the mechanisms underlying depression and gain greater insights into antidepressant therapy.

METHODS

In this study, we first established an effective and feasible depression animal model of chronic unpredictable mild stress (CUMS) and behavioral testing was evaluated by the forced swim test (FST), the tail suspension test (TST) and the sucrose preference test. Following pretreatment with Rh2 (10 and 20 mg/kg), the immobility time of mice was reduced without affecting locomotor activity in both the FST and TST. Western blotting and immunofluorescence were used to investigate the activation of the hippocampal BDNF signaling pathway and hippocampal neurogenesis.

RESULTS

Different concentrations of Rh2 significantly reduced depressive-like symptoms in CUMS-induced mice and downregulated the effects of the BDNF signaling cascade and neurogenesis in the hippocampus. Furthermore, the administration of K252a completely prevented the antidepressant-like activity of Rh2 in mice.

CONCLUSION

The results indicated that Rh2 possesses the antidepression action via the positive regulation of the BDNF-TrkB pathway.

Electroacupuncture Prevents the Depression-Like Behavior by Inhibiting the NF-κB/NLRP3 Inflammatory Pathway in Hippocampus of Mice Subjected to Chronic Mild Stress

BACKGROUND

The precise physiological mechanisms of acupuncture in the treatment of depression are still unknown. This study aimed to observe the effects of electroacupuncture (EA) on depression-like behavior of mouse in chronic mild stress (CMS) model and explore the underlying mechanism.

METHODS

The depression model was established by using CMS method for 6 weeks. After the third week of the CMS paradigm, EA treatment was performed daily for 15 min over a period of 3 weeks. The antidepressant-like effects of EA were evaluated using the sucrose preference test and the forced swimming test (FST). The protein levels of the nuclear factor-kappa B (NF-κB), p-NF-κB, inhibitor of NF-κB, p-IκBα, NOD-like receptor protein 3, interleukin (IL)-6, IL-1β, IL-18, and tumor necrosis factor-α (TNF-α) in hippocampus of mice were detected.

RESULTS

Sucrose preference was decreased after 6 weeks of CMS and the effects of CMS was reversed by EA. CMS increased immobility time and decreased latency to the first immobility in the FST test, but these effects were reversed by EA. CMS-induced nuclear entry of NF-κB (nuclear/cytoplasmic ratio of NF-κB) with an increase in protein levels of p-NF-κB and p-IκBα in the hippocampus. The CMS also increased NLRP3 levels in the hippocampus. However, these effects were reversed by EA. In addition, the levels of IL-6, IL-1β, IL-18, and TNF-α in the hippocampus were increased by CMS, and these effects of stress were reversed by EA.

CONCLUSION

EA prevented CMS-induced depressive-like behaviors by inhibiting NF-κB/NLRP3 inflammatory pathway.

Dopaminergic signaling in prefrontal cortex contributes to the antidepressant effect of electroacupuncture: An iTRAQ-based proteomics analysis in a rat model of CUMS

Electroacupuncture (EA) is used as an adjunctive treatment for depression. This study was conducted to evaluate the efficacy and mechanisms of EA in the depressive rat model induced by chronic unpredictable mild stress (CUMS) in male adult Wistar rats. The underlying mechanisms were explored by using isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analysis of the proteins in the prefrontal cortex (PFC), and observing the number of the PFC neurons stained with hematoxylin and eosin (H&E) and synaptic morphological changes under transmission electron microscopy (TEM). The results showed that EA plus paroxetine (EA + Par) for 1 week significantly relieved depression-like anhedonia symptoms and improved anxiety-like behavior, accompanied by the improvements in synaptic morphology and a significant increase of PFC neurons. Moreover, EA or paroxetine alone significantly alleviated anhedonia symptoms after 2 weeks of intervention. Additionally, iTRAQ analysis showed that dopaminergic signaling was significantly altered in CUMS rats after 1 week of EA treatment. As the critical enzyme of this pathway, aromatic-l-amino-acid decarboxylase (DDC) was significantly upregulated after the treatment with EA + Par for 1 week. These findings suggested that the dopaminergic signaling pathway in PFC may be involved in the antidepressant mechanisms of EA.

Electroacupuncture improves synaptic plasticity by regulating the 5-HT1A receptor in hippocampus of rats with chronic unpredictable mild stress

Objectives

To investigate the antidepressant effects of electroacupuncture (EA) on chronic unpredictable mild stress (CUMS) in rats, as well as the effects of EA on hippocampal neurons, synaptic morphology, and 5-hydroxytryptamine (HT) receptor expression.

Methods

Forty adult male Wistar rats were randomly divided into normal control, CUMS, EA, and paroxetine groups. CUMS modeling was performed for 21 days, followed by 14 days of intervention: rats in the EA group underwent stimulation of GV20 and GV29 acupuncture points for 30 minutes daily; rats in the paroxetine group were administered paroxetine daily. Behavioral tests, transmission electron microscopy, western blotting, and real-time quantitative polymerase chain reaction were used to evaluate the effects of the intervention.

Results

EA treatment reversed the behavioral changes observed in rats due to CUMS modeling; it also improved the pathological changes in organelles and synaptic structures of hippocampal neurons, and upregulated the protein and mRNA expression levels of 5-HT1A receptor. There were no significant differences in 5-HT1B receptor protein and mRNA expression levels among the groups.

Conclusions

EA treatment can alleviate depression-like symptoms in CUMS rats. The underlying mechanism may include promoting the expression of 5-HT1A receptor mRNA and protein, thereby improving synaptic plasticity in the hippocampus.

The mechanism of electroacupuncture for depression on basic research: a systematic review

BACKGROUND

Electroacupuncture (EA) is generally accepted as a safe and harmless treatment option for alleviating depression. However, there are several challenges related to the use of EA. Although EA has been shown to be effective in treating depression, the molecular mechanism is unclear.

OBJECTIVE

To reveal the therapeutic effect of EA and its possible mechanism in the treatment of depression.

SEARCH STRATEGY

We performed a systematic search according to PRISMA guidelines. We electronically searched PubMed, Web of Science (WOS), the China National Knowledge Infrastructure (CNKI), Wanfang Data Information Site and the VIP information database for animal studies in English published from the inception of these databases to December 31, 2019.

INCLUSION CRITERIA

Electronic searches of PubMed, WOS, the CNKI, Wanfang and the VIP database were conducted using the following search terms: (depression OR depressive disorder OR antidepressive), (rat OR mouse) AND (acupuncture OR EA).

DATA EXTRACTION AND ANALYSIS

The data were extracted primarily by one author, and a follow-up review was conducted by the other authors.

RESULTS

Twenty-eight articles met the inclusion criteria. The most commonly used method for inducing depression in animal models was 21 days of chronic unpredictable mild stress. For the depression model, the most commonly selected EA frequency was 2 Hz. Among the 28 selected studies, 11 studies observed depression-related behaviors and used them as indicators of EA efficacy. The other 17 studies focused on mechanisms and assessed the indexes that exhibited abnormalities that were known to result from depression and then returned to a normal range after EA treatment. Treatment of depression by EA involves multiple therapeutic mechanisms, including inhibition of HPA axis hyperactivity and inflammation, regulation of neuropeptides and neurotransmitters, modulation of the expression of particular genes, restoration of hippocampal synaptic plasticity, increased expression of BDNF, and regulation of several signaling pathways.

CONCLUSIONS

This review reveals that the mechanisms underlying the effect of acupuncture involve multiple pathways and targets, suggesting that acupuncture is a wholistic treatment for people rather than for diseases. Our findings also explain why acupuncture can treat various disorders in addition to depression.

Effects of Baihui electroacupuncture in a rat model of depression

Background

This study aimed to investigate the effect of electroacupuncture (EA) on behavior in a rat model of chronic unpredictable mild stress (CUMS) and to explore the underlying molecular mechanisms.

Methods

A total of 45 adult male Sprague-Dawley rats were randomly divided into three groups: the control, CUMS, and CUMS plus EA groups. Rats in the CUMS and EA groups were subjected to a 3-week CUMS condition, while rats in the EA group received EA at the Baihui (GV 20) acupoint (2 Hz, 0.6 mA) for 10 min once daily before being subjected to the CUMS condition. The sucrose preference test (SPT) was used as a measure to infer activation of the pleasure response to depression-like behaviour. After the behavioral test, 5-bromodeoxyuridine (BrdU) was intraperitoneally injected (100 mg/kg) and brain samples were collected 24 h later for the detection of hippocampal BrdU. Cell proliferation was determined according to the proportion of BrdU-positive cells. Brain-derived neurotrophic factor (BDNF) expression was detected.

Results

The severity of anhedonia, BDNF⁺ cells, and BrdU⁺ neurons in DG significantly decreased in CUMS rats, and was accompanied by a reduced BDNF and BrdU⁺ expression (P<0.05). After EA, the low levels of BDNF⁺ cells and BrdU⁺ expression and the depression-like behavior increased markedly (P<0.05).

Conclusions

EA contributes to neuroprotection against CUMS by enhancing BDNF expression and improving hippocampal neurogenesis.

Metabolomics analysis of the antidepressant prescription Danzhi Xiaoyao Powder in a rat model of Chronic Unpredictable Mild Stress (CUMS)

ETHNOPHARMACOLOGICAL RELEVANCE

Danzhi Xiaoyao Powder (DZXY) is a classical prescription, that has been extensively used in traditional Chinese medicine (TMC) to treat depression for many years. However, the mechanism of DZXY is still unclear.

AIM OF THE STUDY

The aim was to investigate the mechanism of the antidepressant effect of DZXY on a rat model of chronic unpredictable mild stress (CUMS).

MATERIALS AND METHODS

Forty male SD (Sprague-Dawley) rats with similar open field test (OFT) results were randomLy divided into a control group (n = 10) and an experimental group (n = 30). A depression model was established in the experimental group using the CUMS method. After the CUMS model was established successfully, the rats were randomLy divided into a depression model group and a DZXY group. The DZXY group was fed DZXY, while the depression model group and control group were given an equal amount of 0.5% sodium carboxymethyl cellulose suspension. Intragastric administration was performed once daily for 14 consecutive days. Animal weight, the sugar preference test, the open field test and the forced swimming test were used to evaluate the modeling effect and the antidepressant effect of DZXY. After the experiment, the plasma of rats was collected and the changes in plasma metabolites were analyzed by UPLC/Q-TOF-MS. The UPLC/Q-TOF-MS spectra data were evaluated by pattern recognition analysis to determine the changes in endogenous metabolites in the rat plasma samples.

RESULTS

The results of the behavioral investigation showed that the rat model of depression was successfully replicated and that DZXY had an antidepressant effect. Using the UPLC-MS/MS metabolomics platform, partial least squares (PLS) and orthogonal partial least squares (OPLS), metabolic profile models (R2 and Q2 ≥ 0.5) of rat plasma were successfully constructed. The model could distinguish among the control group, the depression model group and the DZXY group. Finally, 38 differential metabolites were identified in the plasma. According to KEGG (http://www.kegg.jp) pathway analysis, amino acid metabolism, lipid metabolism, purine metabolism, the prolactin signaling pathway and bile secretion were enriched and represented the main metabolic pathways influenced in the plasma.

CONCLUSIONS

This study successfully established a CUMS depression model. A total of 38 differential metabolites associated with depression were identified in the plasma of rats, 24 of which were modulated by DZXY. These results suggest that DZXY can improve excitability and play an antidepressant role by regulating phenylalanine metabolism, arachidonic acid metabolism, porphyrin metabolism, D-arginine and D-ornithine metabolism, steroid hormone biosynthesis, unsaturated fatty acid biosynthesis and steroid biosynthesis.

Jiao-Tai-Wan Ameliorates Depressive-Like Behavior through the A1R Pathway in Ovariectomized Mice after Unpredictable Chronic Stress

Objective

This study was aimed at observing the effect Jiao-Tai-Wan in menopausal depression.

Methods

In this paper, we used ovariectomized mice subjected to chronic unpredictable stress as a menopausal depression model. After the chronic stress, mice were administrated with JTW (3.3 and 6.6mg/kg) and imipramine (10 mg/kg) for 14 days. On the 14th day, mice were subjected to the behavior test like the forced swim test, tail suspension test, and locomotor activity or were sacrificed to assess the protein changes in different brain regions.

Results

The administration of JTW at doses of 3.3 and 6.6mg/kg (p.o.) significantly shortened the duration of immobility in forced swim and tail suspension tests. There was no obvious difference in locomotor activity among all the groups. The western blot analysis data indicated that treatment with JTW (3.3 and 6.6 mg/kg, p.o.) prominently increased the A₁R protein and the downstream protein ERK1/2 levels in the prefrontal cortex and hippocampus. However, the administration of JTW did not influence c-Fos protein in either the prefrontal cortex or hippocampus.

Conclusion

Our findings suggest that JTW plays a vital role in ameliorating menopausal depression symptoms in the A₁R-ERK1/2 pathway in the prefrontal cortex and hippocampus.

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.

Effects and Mechanisms of Electroacupuncture on Chronic Inflammatory Pain and Depression Comorbidity in Mice

Comorbidity of chronic pain and major depression disorder (MDD) are common diseases. However, the mechanisms of electroacupuncture (EA) and the responses of N-methyl-D-aspartate receptors in the brain remain unclear. Three injections of complete Freund's adjuvant (CFA) were administered to induce chronic inflammatory pain (CIP). EA was then performed once every other day from days 14 to 28. Behavior tests of chronic pain and depression were evaluated to make sure of the successful induction of comorbidity. We used Western blotting to analyze brain tissue from the prefrontal cortex (PFC), hippocampus, and hypothalamus for levels of phosphorylated N-methyl-D-aspartate receptor subunit 1 (pNR1), NR1, pNR2B, NR2B, and calcium/calmodulin-dependent protein kinase type II alpha isoform (pCaMKIIα). The mechanical hyperalgesia, thermal hyperalgesia, and depression were observed in the CIP group. Furthermore, decreased levels of N-methyl-D-aspartate receptors (NMDARs) were also noted. Not Sham EA but EA reversed chronic pain and depression as well as the decreased levels of NMDA in the signaling pathway. The CFA injections successfully induced a significant comorbidity model. EA treated the comorbidity by upregulating the NMDA signaling pathway in the PFC, hippocampus, and hypothalamus. Our results indicated significant mechanisms of comorbidity of chronic pain and MDD and EA-analgesia that involves the regulation of the NMDAR signaling pathway. These findings may be relevant to the evaluation and treatment of comorbidity of chronic pain and MDD.

The Molecular Signatures of Acute-immobilization-induced Antinociception and Chronic-immobilization-induced Antinociceptive Tolerance

In the present study, the productions of antinociception induced by acute and chronic immobilization stress were compared in several animal pain models. In the acute immobilization stress model (up to 1 hr immobilization), the antinociception was produced in writhing, tail-flick, and formalin-induced pain models. In chronic immobilization stress experiment, the mouse was enforced into immobilization for 1 hr/day for 3, 7, or 14 days, then analgesic tests were performed. The antinociceptive effect was gradually reduced after 3, 7 and 14 days of immobilization stress. To delineate the molecular mechanism involved in the antinociceptive tolerance development in the chronic stress model, the expressions of some signal molecules in dorsal root ganglia (DRG), spinal cord, hippocampus, and the hypothalamus were observed in acute and chronic immobilization models. The COX-2 in DRG, p-JNK, p-AMPKα1, and p-mTOR in the spinal cord, p-P38 in the hippocampus, and p-AMPKα1 in the hypothalamus were elevated in acute immobilization stress, but were reduced gradually after 3, 7 and 14 days of immobilization stress. Our results suggest that the chronic immobilization stress causes development of tolerance to the antinociception induced by acute immobilization stress. In addition, the COX-2 in DRG, p-JNK, p-AMPKα1, and p-mTOR in the spinal cord, p-P38 in the hippocampus, and p-AMPKα1 in the hypothalamus may play important roles in the regulation of antinociception induced by acute immobilization stress and the tolerance development induced by chronic immobilization stress.

Acupuncture induces adenosine in fibroblasts through energy metabolism and promotes proliferation by activating MAPK signaling pathway via adenosine3 receptor

Acupuncture has many advantages in the treatment of certain diseases as opposed to drug therapy. Besides, adenosine has been revealed to affect cellular progression including proliferation. Therefore, this study aimed at exploring the mechanism involving acupuncture stress and adenosine in fibroblast proliferation. The fibroblasts from fascia tissues of the acupoint area (Zusanli) were stimulated by different levels of stress, different concentrations of adenosine, and agonist or antagonist of A₃ receptor (A₃ R) to investigate the effect of stress stimulation, adenosine, and adenosine-A₃ R inhibition on fibroblasts. Then, the fibroblasts were treated with stress stimulation of 200 kPa or/and mitogen-activated protein kinase (MAPK) blocker. We revealed that stress stimulation and the binding of adenosine and A₃ R promoted fibroblast proliferation in the fascial tissue, increased the expression of immune-related factors, adenosine and A₃ R, and activated the MAPK signaling pathway. MAPK signaling pathway also directly affected the expression of adenosine, A₃ R, and immune-related factors. Stress stimulation and adenosine treatment upregulated A₃ R expression, and then activated the MAPK signaling pathway, which could in turn upregulate expression of adenosine, A₃ R and immune-related factors, and promote cell proliferation. Adenosine is shown to form a positive feedback loop with the MAPK signaling pathway. Collectively, stress stimulation in vitro induces the increase of adenosine in fibroblasts through the energy metabolism and activation of the MAPK signaling pathway through A₃ R, ultimately promoting fibroblast proliferation.

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.

Effect of Electroacupuncture at Different Acupoints on the Expression of NMDA Receptors in ACC and Colon in IBS Rats

Objective

To observe the effects of electroacupuncture (EA) at different acupoints on the expression of N-methyl-D-aspartate receptor (NMDA receptor ) and behaviors in irritable bowel syndrome (IBS) rats.

Methods

Wistar rats were randomly divided into blank control group (blank group, n=10) and model preparation group (n=50); experimental rat model of IBS was established by the “neonatal maternal separation and acetic acid enema” combined with “colorectal distension stimulation” method. A total of 50 IBS rats were randomly assigned to five groups of 10 each: model group, Yintang (GV29) group, Neiguan (PC6) group, Tianshu (ST25) group, and Zusanli (ST36) group. Rats in four treatment groups, aged 9 weeks old, were treated with EA by HANS with a sparse-dense wave with a frequency of 2/100 Hz, current of 0.1-0.3mA, and 20 min/stimulation, every other day for a total of 5 sessions. After treatment, the abdominal visceral sensitivity was evaluated by abdominal withdrawal reflex (AWR), and the psychological and emotional behavior of rats were evaluated by the open-field test (OFT). The expression of NMDA receptors in anterior cingulate cortex (ACC) was detected by Quantitative Real-time PCR, and the positive expression of NMDA receptors in colon was detected by immunohistochemistry.

Results

The IBS rat's abdomen is more sensitive and irritable; NR1, NR2A, and NR2B in ACC and NR1 and NR2B in colon of rats significantly increased in the model group versus the normal group (P<0.01) and were inhibited in all treatment groups (P<0.01, P<0.05). Additionally, NR2A and NR2B in ACC reduced more in GV29 group (P<0.01) than in other treatment groups (P all<0.05) compared with the model group. The expression of NR2B in colon was significantly inhibited in ST36 group (P<0.01) and inhibited in GV29 group and ST25 group (P all <0.05) compared with the model group. And the expression of NR2B in colon was more inhibited in ST36 group than in PC6 group (P<0.01).

Conclusions

EA at different acupoints could obviously relieve abdominal pain and abnormal behaviors in IBS rats in different degrees of effects. The effect of abdominal pain-relief, from greatest to least, is ST25, ST36, GV29, and PC6, while the effect of relieving abnormal behaviors caused by IBS, from greatest to least, is GV29, PC6, ST36, and ST25. There are significant differences in the expressions of NMDA receptors in ACC and colon among different acupoints. This difference should be related to the location distribution and indications of acupoints.

An estradiol-independent BDNF-NPY cascade is involved in the antidepressant effect of mechanical acupuncture instruments in ovariectomized rats

Menopause-related depression devastates women's quality of life after middle age. Previous research has shown that estrogen hormone therapy has serious adverse effects; thus, complementary and integrative therapies have been considered clinically. The present study investigates whether stimulation of an acupoint using a mechanical acupuncture instrument (MAI) can mitigate depression-like behavior caused by estrogen deficiency in ovariectomized (OVX) rats. The animals were divided into Sham OVX, OVX, OVX + Sameumgyo (SP6) and OVX + NonAcu (non-acupuncture point) groups. MAI stimulation significantly increased the total distance traveled in the open-field test and the number of open-arm entries in the elevated plus maze and decreased the duration of immobility in the forced swim test. In addition to this decrease in depression-like behavior, brain-derived neurotrophic factor (BDNF) and neuropeptide Y (NPY) release increased in the hippocampus in response to MAI treatment, but estradiol levels did not recover. Furthermore, microinjection of the BDNF receptor antagonist ANA-12 (0.1 pmol/1 μl) into the hippocampus before MAI stimulation significantly suppressed the recovery of NPY levels. Taken together, these findings indicate that MAI stimulation at SP6 facilitates an estradiol-independent BDNF-NPY cascade, which may contribute to its antidepressant effects in OVX rats, an animal model of menopausal disorders.

The Role of MAPK and Dopaminergic Synapse Signaling Pathways in Antidepressant Effect of Electroacupuncture Pretreatment in Chronic Restraint Stress Rats

Acupuncture has demonstrated the function in ameliorating depressive-like behaviors via modulating PKA/CREB signaling pathway. To further confirm the antidepressant mechanism of EA on the mitogen-activated protein kinase (MAPK) and dopaminergic synapse signaling pathways, 4 target proteins were detected based on our previous iTRAQ analysis. Rats were randomly divided into control group, model group, and electroacupuncture (EA) group. Except for the control group, all rats were subjected to 28 days of chronic restraint stress (CRS) protocols to induce depression. In the EA group, EA pretreatment at Baihui (GV20) and Yintang (GV29) was performed daily (1 mA, 2 Hz, discontinuous wave, 20 minutes) prior to restraint. The antidepressant-like effect of EA was measured by body weight and open-field test. The protein levels of DAT, Th, Mapt, and Prkc in the hippocampus were examined by using Western blot. The results showed EA could ameliorate the depression-like behaviors and regulate the expression levels of Prkc and Mapt in CRS rats. The effect of EA on DAT and Th expression was minimal. These findings implied that EA pretreatment could alleviate depression through modulating MAPK signaling pathway. The role of EA on dopaminergic synapse signaling pathways needs to be further explored.

Acupuncture for behavioral changes of experimental depressive disorder: a systematic review and meta-analysis

Acupuncture is considered to be a promising alternative therapy for depression. Nevertheless, up to now, it remains controversial on the effects exerted by acupuncture on behavioral changes in depression models. Consequently, it’s necessary to develop a systematic review and meta-analysis to assess the effect of acupuncture for model rats of depression. Ultimately, 90 studies involving 1861 models were identified. Behavioral indicators including the number of crossings (NC) and the number of rearings (NR) in open field test (OFT), the capacity of sucrose intake (CSI) and the rate of sucrose intake (RSI) in sucrose intake test (SIT), final weight (FW) and gain weight (GW) were employed as main outcomes in depression model rats. The pooled results showed that acupuncture had not less effect than western medicine on improving NC, NR, FW, GW, RSI (P > 0.05). However, the CSI improvement was poorer compared with west medicine (P < 0.05). In conclusion, acupuncture has not less effect on behavior changes than western medicine, including improving NC, NR, RSI, FW and GW in depression models.

Antidepressant-like effects of acupuncture involved the ERK signaling pathway in rats

Background

The extracellular signal-regulated kinase (ERK) signaling pathway is considered to be associated with the pathogenesis and treatment of depression. Acupuncture has been demonstrated to ameliorate depression-related behavior and promote neurogenesis. In this study, we explored the role of the ERK signaling pathway in the antidepressant-like effects of acupuncture in rats exposed to chronic unpredictable mild stress (CUMS).

Methods

Eighty male Sprague–Dawley rats were randomly divided into eight groups: control group, model group, model + Acupuncture group (Acu group), model + fluoxetine group (FLX group), model + DMSO group (DMSO group), model + PD98059 group (PD group), model + Acupuncture + PD98059 group (Acu + PD group) and model + fluoxetine + PD98059 group (FLX + PD group). Except for the control group, all rats were subjected to 3 weeks of CUMS protocols to induce depression. Acupuncture was carried out for 10 min at acupoints of Baihui (GV-20) and Yintang (GV-29) each day during the experimental procedure. The ERK signaling pathway was inhibited using PD98059 through intracerebroventricular injection. The depression-like behaviors were evaluated using the sucrose intake and open-field tests. The protein levels of ERK1/2, phosphor (p)-ERK1/2, cAMP response element-binding protein (CREB), p-CREB and brain-derived neurotrophic factor (BDNF) in the hippocampus were examined using western blot.

Results

Acupuncture ameliorated the depression-like behaviors and dysfunction of the ERK signaling pathway in the hippocampus of CUMS rats. PD98059 pretreatment inhibited the improvements brought about by acupuncture on the ERK signaling pathway.

Conclusions

Taken together, our results indicated that acupuncture had a significant antidepressant-like effect on CUMS-induced depression model rats, and the ERK signaling pathway was implicated in this effect.

A microarray study of chronic unpredictable mild stress rat blood serum with electro-acupuncture intervention

In the present study, we investigated the changes of microRNA (miRNA) expression upon depression and electro-acupuncture (EA) intervention in chronic unpredictable mild stress (CUMS) rats using microarray analysis. Results showed that EA intervention remarkably improved behavioral indexes in terms of crossing number, rearing number, sucrose preference and body weight of CUMS rats. Microarray analysis revealed that a total of 153 differentially expressed miRNAs were regulated by CUMS, and the expression of 180 differentially expressed miRNAs was changed after EA intervention. Among these miRNAs, two miRNAs were significantly up-regulated and four miRNAs were significantly down-regulated by CUMS. Moreover, four miRNAs were significantly up-regulated and 12 miRNAs were significantly down-regulated after EA intervention. The expressions of miR-383-5p and miR-764-5p were up-regulated after CUMS, while their expressions were down-regulated by EA intervention. Further analysis showed that 1260 possible target genes were predicted for miR-383-5p and miR-764-5p, and 97 pathways and 137 gene ontology (GO) were involved. Among these pathways and GO, about 20 pathways and 21 GO were related to depression. Changes of miR-383-5p and miR-764-5p indicated that EA might exert its therapeutic effect on depression through promoting the neurotrophy and inhibiting the abnormal apoptosis of neurons as well as other correlative signal pathways. In conclusion, our present study enriched the understanding of pathological process of depression and revealed possible mechanisms of EA on depression.