Effects of intensity of electroacupuncture on chronic pain in patients with knee osteoarthritis: a randomized controlled trial

P2Y12 receptor as a new target for electroacupuncture relieving comorbidity of visceral pain and depression of inflammatory bowel disease

Background

The P2Y12 receptor is a kind of purinoceptor that is engaged in platelet aggregation, and P2Y12 inhibitors have been used in clinical antithrombotic therapy. The P2Y12 receptor in microglia induces interleukin-1β (IL-1β) expression, which is a key mediator of depression in the brain. Although peripheral P2Y12 is involved in neuropathic pain, whether P2Y12 expression in the medial prefrontal cortex (mPFC) is associated with comorbidities of visceral pain and depression remains unclear. Accumulating evidence suggests that electroacupuncture (EA) is effective in treating inflammatory bowel disease (IBD), but its mechanism is unknown. This study aimed to determine whether P2Y12 expression in the mPFC is associated with comorbidities of visceral pain and depression in IBD and whether EA treats IBD by targeting the P2Y12 receptor.

Methods

We used 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced IBD mice. P2Y12 short hairpin RNA (shRNA) was stereotaxically injected into the bilateral mPFC. EA was performed on bilateral “Dachangshu” (BL25) acupoints once a day for 7 days. Von Frey filaments and colorectal distension were used to detect the mechanical pain threshold and visceral pain sensitivity. The sucrose preference test, tail suspension test and forced swimming test were used to evaluate depression in mice. Western blotting was used to test the expression of P2Y12 and IL-1β. Immunofluorescence staining was used to assess microglial activity.

Results

We found that IBD mice presented visceral pain and depression associated with increased P2Y12 expression in the mPFC. P2Y12 shRNA significantly attenuated visceral pain and depression in IBD mice. P2Y12 shRNA significantly downregulated IL-1β expression and inhibited the activation of microglia in the mPFC of IBD mice. Meanwhile, EA played a similar role of P2Y12 shRNA. EA significantly downregulated P2Y12 expression, weakened the activation of microglia, and then inhibited IL-1β expression in the mPFC, thus relieving visceral pain and depression in IBD mice.

Conclusion

The present study provided new ideas that the P2Y12 receptor in the mPFC could be a new target for the treatment of comorbid visceral pain and depression by EA. This may not only deepen our understanding of the analgesic and antidepressant mechanisms of EA but also promote the application of EA to treat IBD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00553-9.

Electroacupuncture Upregulates HIF-1α and SOX9 Expression in Knee Osteoarthritis

Electroacupuncture (EA) has been clinically used in knee osteoarthritis broadly and proved to be effective than other therapies with fewer side effects; however, the mechanism of electroacupuncture to work on cartilage remains unclear. In this study, we aimed to evaluate the effect of EA treatment on cartilage and the relationship between EA and proteins such as HIF-a and SOX9. EA (dilatational wave, 3-15 HZ, 1 mA) has been applied to bilateral Zusanli (ST36), Xuehai (SP10), Taixi (KI3), and Yanglingquan (GB34) of rats. Results showed that the cartilage of the knee osteoarthritis group had obvious damage and fissure formation while the EA group showed that the cartilage destruction was generally milder. In addition, the protein expression levels of HIF-1α, and chondrogenic markers such as Sox9, and ACAN in the electroacupuncture group were higher than those in the ACLT group. Also, the extracellular matrix protein expression levels of MMP13 and ADAMTS5 were decreased in the EA group. These findings indicate that EA could alleviate the severity of knee osteoarthritis, and HIF-a and SOX9 may closely attribute to the treatment.

Benefits of electroacupuncture and a swimming association when compared with isolated protocols in an osteoarthritis model

Background and aim

Osteoarthritis (OA) is characterized by pain and inflammation. Electroacupuncture (EA) and swimming (SW) are non-pharmacological interventions recommended for treating OA. The study evaluated the benefits of electroacupuncture (EA) and swimming (SW) association when compared with isolated protocols in an OA rodent model. Experimental.

Procedures

An ankle monoarthritis model was induced in rats by applying Complete Freund's Adjuvant (CFA). After seven days of induced OA, the groups were submitted to EA (ST36 and the GB 30 Acupoint), SW, or the EA + SW protocol. The nociceptive behavior was measured by the Von Frey test, the Cold Stimulation test, and the Paw Flick Immersion test. Inflammatory activity was evaluated by measuring TNF levels, myeloperoxidase, NAGase, immunological parameters and the histology from the subcutaneous tissue.

Results

Compared to CFA group, EA decreased the nociceptive scores in the cold stimulation test (p < 0.05), and it also increased the latency time in thermal cold (p < 0.01) and heat hyperalgesia (p < 0.001). Also, EA reduced NAGase (p < 0.01). SW reduced the edema (p < 0.05) and did not increase the inflammatory infiltrates or congestion, neither in the histological measurements nor by analyzing the levels of TNF. The association of EA + SW decreased the neutrophils and the monocytes, MPO (p < 0.05), and the glutamate levels in the cerebrospinal fluid (CSF, p < 0.001).

Conclusion

There were statistical differences between combination therapy and monotherapy as seen by the inflammatory parameters, which could be associate to the delay of the chronification osteoarthritis retardation. However, EA + SW did not show benefits when compared to isolated protocols in nociceptive behavior.

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Electroacupuncture (EA) extended the latency time in the thermal hyperalgesia assay.

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The swimming protocol did not increase the inflammatory infiltrates.

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EA and swimming decreased the glutamate levels in the cerebral spinal fluid.

Strong Twirling-Rotating Manual Acupuncture with 4 r/s Is Superior to 2 r/s in Relieving Pain by Activating C-Fibers in Rat Models of CFA-Induced Pain

Background

Manual acupuncture (MA) with different stimulus frequencies may give rise to varying acupuncture effects. However, the intensity-effect relationship and the underlying mechanisms of MA remain unclear.

Objective

To compare the analgesic effects of different frequencies of twirling-rotating MA on rats with complete Freund's adjuvant- (CFA-) induced pain and explore the underlying mechanism via peripheral sensory nerves.

Methods

First, 36 healthy male Wistar rats were randomly divided into 6 groups: control group, 2 r/s MA group (twirling-rotating MA with the frequency of 2 revolutions per second), 4 r/s MA group (twirling-rotating MA with the frequency of 4 revolutions per second), CFA group, CFA + 2 r/s MA group, and CFA + 4 r/s MA group. Rats in three CFA groups received an intraplantar injection of CFA to establish a pain model, while the rats in other three groups received an intraplantar injection of saline. Rats in the 2 r/s MA group and 4 r/s MA group were treated with the corresponding frequencies of twirling-rotating MA on bilateral Zusanli (ST36) and Kunlun (BL60) for 7 days. The ipsilateral nociceptive thresholds (paw withdrawal latency; PWL) were tested to evaluate the analgesic effects. Second, 9 healthy male Wistar rats were randomly divided into 3 groups: control group, 2 r/s MA group, and 4 r/s MA group. The proportion of C-fiber neurons (calcitonin gene-related peptide- (CGRP-) positive neurons) and A-fiber neurons (neurofilament 200- (NF200-) positive neurons) in the dorsal root ganglia (DRG) activated by MA were quantitatively analyzed with the morphological immunofluorescence staining method. Third, 30 healthy male Wistar rats were randomly divided into 6 groups: control group, CFA group, CFA + 2 r/s MA group, CFA + 2 r/s MA + RTX group, CFA + 4 r/s MA group, and CFA  + 4 r/s MA + RTX group. Resiniferatoxin (RTX) was injected into the acupoints before acupuncture. PWL was evaluated to investigate the analgesic effect.

Results

Both types of MA treatment increased the PWL of saline-injecting rats and pain model rats. Moreover, 4 r/s MA was superior to 2 r/s MA in increasing PWL. A higher quantity of excited C-fiber neurons was observed following 4 r/s MA than 2 r/s MA, while the reverse was observed in the activation of A-fiber neurons. Following the injection of RTX to inhibit the activation of C-fibers, the analgesic effect of 4 r/s MA reduced significantly but not of 2 r/s MA.

Conclusion

Strong MA (4 r/s MA) has superior analgesic effects to gentle MA (2 r/s MA) on CFA model rats, which is associated with C-fiber activation.

5-HT7 Receptor Is Involved in Electroacupuncture Inhibition of Chronic Pain in the Spinal Cord

Knee osteoarthritis (KOA) is a common and disabling condition characterized by attacks of pain around the joints, and it is a typical disease that develops chronic pain. Previous studies have proved that 5-HT₁, 5-HT₂, and 5-HT₃ receptors in the spinal cord are involved in electroacupuncture (EA) analgesia. The 5-HT₇ receptor plays antinociceptive role in the spinal cord. However, it is unclear whether the 5-HT₇ receptor is involved in EA analgesia. The 5-HT₇ receptor is a stimulatory G-protein (Gs)-coupled receptor that activates adenylyl cyclase (AC) to stimulate cyclic adenosine monophosphate (cAMP) formation, which in turn activates protein kinase A (PKA). In the present study, we found that EA significantly increased the tactile threshold and the expression of the 5-HT₇ receptor in the dorsal spinal cord. Intrathecal injection of 5-HT₇ receptor agonist AS-19 mimicked the analgesic effect of EA, while a selective 5-HT₇ receptor antagonist reversed this effect. Moreover, intrathecal injection of AC and PKA antagonists prior to EA intervention prevented its anti-allodynic effect. In addition, GABA_A receptor antagonist bicuculline administered (intrathecal, i.t.) prior to EA intervention blocked the EA effect on pain hypersensitivity. Our data suggest that the spinal 5-HT₇ receptor activates GABAergic neurons through the Gs–cAMP–PKA pathway and participates in EA-mediated inhibition of chronic pain in a mouse model of KOA.

Effect of Electroacupuncture Combined with Guizhi Gegen Decoction on Cervical Vertigo and Its Influence on TCD of Vertebrobasilar Artery, Blood Rheology Indexes, and Quality of Life

Cervical vertigo is a common clinical disease. In this study, we investigated the clinical efficacy of adding the treatment protocol of Gui Zhi Ge Gen Tang and electroacupuncture to the Western medical treatment in cervical vertigo. The results showed that the total effective rate of the study group was higher than that of the control group (P < 0.05). After treatment, the vertigo, headache, neck and shoulder pain, daily life and work, and psychological and social adjustment scores were higher in the study group than in the control group (P < 0.05). LVA, RVA, and VB were higher in the study group than in the control group after treatment (P < 0.05). The whole blood viscosity high cut, whole blood viscosity low cut, and plasma viscosity levels were lower in the study group than in the control group after treatment (P < 0.05). After treatment, PF, RF, RE, BP, GH, VT, SF, MH, and HT were higher in the study group than those before treatment (P < 0.05). The incidence of adverse reactions was not statistically significant in the study group compared with the control group (P > 0.05). This means that electroacupuncture combined with Gui Zhi Ge Gen Tang can effectively increase the blood flow velocity of the vertebrobasilar artery in patients with cervical vertigo and improve their blood rheology and quality of life with definite efficacy and high safety.

Electroacupuncture and Transcutaneous Electrical Nerve Stimulation Induced Sensations in Bell's Palsy Patients: A Quantitative Current Intensity Analysis

Background

The intensity of electrical acupoint stimulation such as electroacupuncture (EA) and transcutaneous electrical nerve stimulation (TENS) is regulated by the observation of skin shivering or the participant’s comfort response. However, the specific intensity and spatial scope following EA or TENS stimulation are unclear.

Objective

This study aimed to test the stimulatory current intensities of lower and upper sensation thresholds in TENS- and EA-based treatment of Bell’s palsy patients. Also, the spatial scope of the stimulation at these current intensities was simulated and measured quantitatively.

Methods

A total of 19 Bell’s palsy patients were recruited. Six acupoints on the affected side of the face were stimulated by TENS and EA successively at 30-min intervals. During the stimulation, the current intensity was regulated gradually from 0 to 20 mA, and we simultaneously measured the lower (sensory) and upper (tolerability) sensations. After the treatment by TENS and EA, the modified Chinese version of the Massachusetts General Hospital Acupuncture Sensation Scales (C-MMASS) was applied to survey the de-qi sensations during stimulation. Additionally, we analyzed the correlation between current intensities and C-MMASS and comfort scores. Finite element models were established to depict the spatial distribution of electric field gradients at the lower and upper thresholds.

Results

The mean sensory and tolerability thresholds of TENS were 3.91–4.37 mA and 12.33–16.35 mA, respectively. The median sensory and tolerability thresholds of EA were 0.2 mA and 2.0–3.2 mA, respectively. We found a significant correlation between total C-MMASS scores and the current intensities at the tolerability threshold of TENS. The finite element model showed that the activated depths of TENS and EA at the lower threshold were 3.8 and 7 mm, respectively, whereas those at the upper threshold were both 13.8 mm. The cross-sectional diameter of the activated area during TENS was 2.5–4 times larger than that during EA.

Conclusion

This pilot study provided a method for exploring the current intensity at which the de-qi sensations can be elicited by TENS or EA. The finite element analysis potentially revealed the spatial scope of the electrical stimulation at a specific current intensity.

Electroacupuncture-Induced Muscular Inflammatory Pain Relief Was Associated With Activation of Low-Threshold Mechanoreceptor Neurons and Inhibition of Wide Dynamic Range Neurons in Spinal Dorsal Horn

Acupuncture is an effective alternative therapy for pain management. Evidence suggests that acupuncture relieves pain by exciting somatic afferent nerve fibers. However, the mechanism underlying the interaction between neurons in different layers of the spinal dorsal horn induced by electroacupuncture (EA) remains unclear. The aim of this study was to explore the mechanism of EA relieving inflammatory muscle pain, which was associated with activation of the spontaneous firing of low-threshold mechanoreceptor (LTM) neurons and inhibition of wide dynamic range (WDR) neuronal activities in the spinal dorsal horn of rats. Inflammatory muscle pain was induced by injecting complete Freund’s adjuvant into the right biceps femoris muscle. EA with intensity of threshold of A fibers (Ta) in Liangqiu (ST34) muscle considerably inhibited the abnormal spontaneous activities of electromyography (EMG) due to muscle inflammation. While EA with intensity of C-fiber threshold (Tc) increased the abnormal activities of EMG. EA with Ta also ameliorated the imbalance of weight-bearing behavior. A microelectrode array with 750-μm depth covering 32 channels was used to record the neuronal activities of WDR and LTM in different layers of the spinal dorsal horn. The spontaneous firing of LTM neurons was enhanced by EA-Ta, while the spontaneous firing of WDR neurons was inhibited. Moreover, EA-Ta led to a significant inverse correlation between changes in the frequency of WDR and LTM neurons (r = −0.64, p < 0.05). In conclusion, the results indicated that EA could alleviate inflammatory muscle pain, which was associated with facilitation of the spontaneous firing of LTM neurons and inhibition of WDR neuronal activities. This provides a promising evidence that EA-Ta could be applied to relieve muscular inflammatory pain in clinical practice.

Effects of Percutaneous Electrolysis on Endogenous Pain Modulation: A Randomized Controlled Trial Study Protocol

Percutaneous electrolysis consists of the application of a galvanic electrical current throughout an acupuncture needle. It has been previously hypothesized that needling procedures' neurophysiological effects may be related to endogenous pain modulation (EPM). This protocol study describes the design of a double-blind (participant, assessor) randomized controlled trial with the aim to investigate whether percutaneous electrolysis is able to enhance EPM and whether the effect is different between two applications depending on the dosage of the galvanic electrical current. Seventy-two asymptomatic subjects not reporting the presence of pain symptoms the previous 6 months before the study, aged 18-40 years, are randomized into one of four groups: a control group who does not receive any intervention, a needling group who receives a needling intervention without electrical current, a low-intensity percutaneous electrolysis group (0.3 mA × 90 s), and a high-intensity percutaneous electrolysis group (three bouts of 3 mA × 3 s). Needling intervention consists of ultrasound-guided insertion of the needle on the common extensor tendon of the lateral epicondyle. The primary outcome is conditioned pain modulation (CPM), and secondary outcomes include widespread pressure pain sensitivity (pressure pain thresholds (PPT) over the lateral epicondyle, the cervical spine, and the tibialis anterior muscle) and temporal summation (TS). We expected that percutaneous electrolysis would have a greater influence on CPM than an isolated needling procedure and no intervention. In addition, we also postulated that there might be differences in outcome measures depending on the intensity of the electrical current during the percutaneous electrolysis application. This study makes a new contribution to the field of neurophysiological effects of percutaneous electrolysis and needling interventions.

Efficacy of Intensive Acupuncture Versus Sham Acupuncture in Knee Osteoarthritis: A Randomized Controlled Trial

OBJECTIVE

To assess the efficacy of intensive acupuncture (3 times weekly for 8 weeks) versus sham acupuncture for knee osteoarthritis (OA).

METHODS

In this multicenter, randomized, sham-controlled trial, patients with knee OA were randomly assigned to receive electroacupuncture (EA), manual acupuncture (MA), or sham acupuncture (SA) 3 times weekly for 8 weeks. Participants, outcome assessors, and statisticians were blinded with regard to treatment group assignment. The primary outcome measure was response rate, which is the proportion of participants who simultaneously achieved minimal clinically important improvement in pain and function by week 8. The primary analysis was conducted using a Z test for proportions in the modified intent-to-treat population, which included all randomized participants who had ≥1 post-baseline measurement.

RESULTS

Of the 480 participants recruited in the trial, 442 were evaluated for efficacy. The response rates at week 8 were 60.3% (91 of 151), 58.6% (85 of 145), and 47.3% (69 of 146) in the EA, MA, and SA groups, respectively. The between-group differences were 13.0% (97.5% confidence interval [97.5% CI] 0.2%, 25.9%; P = 0.0234) for EA versus SA and 11.3% (97.5% CI -1.6%, 24.4%; P = 0.0507) for MA versus SA. The response rates in the EA and MA groups were both significantly higher than those in the SA group at weeks 16 and 26.

CONCLUSION

Among patients with knee OA, intensive EA resulted in less pain and better function at week 8, compared with SA, and these effects persisted though week 26. Intensive MA had no benefit for knee OA at week 8, although it showed benefits during follow-up.

Electroacupuncture Ameliorates Depressive-Like Behaviors in Poststroke Rats via Activating the tPA/BDNF/TrkB Pathway

BACKGROUND

Electroacupuncture (EA) is a form of physical therapy that has been widely used in clinical practice in China. Post-stroke depression (PSD) is the most common neuropsychiatric complication after stroke. EA has been shown to have beneficial effects on PSD patients. However, the potential mechanism underlying the protective effects of EA on PSD remains unclear. Here, we investigated whether tissue plasminogen activator (tPA)/brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling pathway participates in the therapeutic effects of EA in a rat PSD model.

METHODS

Experimental PSD was induced by combining middle cerebral artery occlusion (MCAO) with chronic unpredictable mild stimulation (CUMS) in adult male rats. Bodyweight gain, neurological score, sucrose preference, and open field test were determined at 0, 7, 14, and 35 days after completing MCAO. The protein expressions of tPA, precursor BDNF (proBDNF), mature BDNF (mBDNF), and TrkB were measured by immunofluorescence and Western blot analysis. The tPA inhibitor plasminogen inhibitor-1 (PAI-1) was used to explore whether tPA plays a crucial role in the protective effects of EA on PSD.

RESULTS

Compared with the sham rats, the PSD rats showed decreased bodyweight, deteriorated neurological score, and significant depressive-like behaviors. EA remarkably reversed bodyweight loss, neurological deficit, and depressive-like behaviors in PSD rats. Immunofluorescence staining and Western blot analysis showed that PSD-induced decreased expression of tPA, mBDNF, and TrkB were prevented by EA. Furthermore, we found that the effects of EA against PSD-induced depressive-like behaviors were abolished by PAI-1, the specific inhibitor of tPA.

CONCLUSION

Our results suggest that the improvement in depressive-like behaviors induced by EA is likely achieved via activation of the tPA/BDNF/TrkB pathway.

Dry needling strategies for musculoskeletal conditions: Do the number of needles and needle retention time matter? A narrative literature review

Acupuncture and dry needling are both minimally invasive procedures that use thin, filiform needles without injectate for the management of a variety of neuromusculoskeletal pain conditions. While the theoretical constructs underlying the use of acupuncture and dry needling are unique, both appear to have the ability to elicit biochemical, biomechanical, endocrinological and neurovascular changes associated with reductions in pain and disability. However, optimal treatment dosage has yet to be determined, and there is a lack of consistency in the literature on the number of needles that should be inserted and the needle retention time. Therefore, the purpose of this narrative review is to further explore the importance of these two variables. While trigger point dry needling advocates single needle insertions via repetitive, quick in-and-out pistoning, most acupuncture and dry needling clinical trials have incorporated multiple needles for five to 40 min. Notably and to date, using a single needle to repeatedly prick trigger points one at a time with fast-in and fast-out pistoning maneuvers has not yet been shown to produce significant and clinically meaningful long term improvements in pain and disability in a wide array of musculoskeletal conditions. Insertion of multiple needles for typically 20-30 min durations has been shown to produce larger treatment effect sizes and longer-lasting outcomes than brief, single-needle strategies. Moreover, the number of needles and needle retention time are two variables associated with treatment dosage and must be carefully matched with specific musculoskeletal conditions and the patient's goals.

Effect of Electroacupuncture versus Sham Electroacupuncture in Patients with Knee Osteoarthritis: A Pilot Randomized Controlled Trial

Objective

To explore the feasibility of evaluating the effectiveness and safety of electroacupuncture versus sham electroacupuncture for patients with knee osteoarthritis (KOA).

Method

A pilot randomized controlled trial was conducted at a teaching hospital in Beijing. A total of 30 patients with KOA (Kellgren grade II or III) were randomly allocated to an eight-week treatment of either electroacupuncture or sham electroacupuncture. Patients and outcome assessors were blinded to group allocation. The primary outcome was the proportion of responders achieving at least 1.14 seconds decrease in the Timed Up and Go Test (TUG) at week eight compared with baseline. The secondary outcomes included the knee range of motion, the knee extensor and flexor muscle strength, Lequesne index, 9-step stair-climb test (9-SCT), and TUG.

Results

Of 30 patients allocated to two groups, 27 (90%) completed the study. The proportion of responders was 53.3% (8 of 15) for electroacupuncture group and 26.7% (4 of 15) for sham electroacupuncture group by the intention-to-treat analysis (P = 0.264). There was no statistically significant difference in TUG between the two groups at eight weeks (P = 0.856). The compliance rate measured according to patients who conformed to the protocol and had received treatments ≥20 times was 93.3% (28 of 30). The dropout rate was 20% (3 of 15). Adverse effects were not reported in the study.

Conclusion

Our research demonstrated that further evaluation of the effectiveness of electroacupuncture versus sham electroacupuncture was feasible and safe for patients with KOA. Whether or not the electroacupuncture can improve the physical functions of knee joint, expand the knee range of motion, and increase the extensor and flexor muscle strength more significantly than sham electroacupuncture, future studies can be designed with larger sample size, randomization design and less biases. This trial is registered with NCT03366363.

Research Trends of Acupuncture Therapy on Knee Osteoarthritis from 2010 to 2019: A Bibliometric Analysis

Background

Acupuncture has been widely applied to relieve knee osteoarthritis (KOA) in many countries. However, the bibliometric analysis of the global use of acupuncture on KOA is largely unknown. Therefore, this study aimed to explore the current status and trends of the global use of acupuncture on KOA in recent 10 years by using CiteSpace (5.6.R3).

Methods

Publications regarding acupuncture therapy for treating KOA between 2010 and 2019 were extracted from the Web of Science database. CiteSpace was used to analyze the number of publications, countries, institutions, journals, authors, cited references and keywords by using standard bibliometric indicators.

Results

A total of 343 publications were retrieved from 2010 to 2019. The total number of publications continually increased over the past four years, and the most active journals, countries, institutions and authors in the field of acupuncture therapy on patients with KOA were identified. The Evid Based Complement Alternat Med (28) was the most prolific journal, and the Ann Intern Med (202) was the most cited journal. The most productive country and institution in this field was China (115) and University of York (18), respectively. Hugh Macpherson (18) was the most prolific author and Witt C ranked the first in the cited authors. In the ranking of frequency in cited reference, the first article was published by Scharf HP (54). The keyword of ‘randomized controlled trial’ ranked first for research developments with the highest citation burst (3.9486). Besides, there were three main frontiers in keywords for KOA research, including ‘research method, ‘age’ and ‘measure of intervention’.

Conclusion

The findings from this bibliometric study provide current status and trends in clinical research of acupuncture therapy on patients with KOA over the past ten years, which may help researchers identify hot topics and explore new directions for future research in this field.

Electroacupuncture intervention of visceral hypersensitivity is involved in PAR-2-activation and CGRP-release in the spinal cord

Electroacupuncture (EA) relieves visceral hypersensitivity (VH) with underlying inflammatory bowel diseases. However, the mechanism by which EA treats ileitis-induced VH is not clearly known. To assess the effects of EA on ileitis-induced VH and confirm whether EA attenuates VH through spinal PAR-2 activation and CGRP release, goats received an injection of 2,4,6-trinitro-benzenesulfonic-acid (TNBS) solution into the ileal wall. TNBS-injected goats were allocated into VH, Sham acupuncture (Sham-A) and EA groups, while goats treated with saline instead of TNBS solution were used as the control. Goats in EA group received EA at bilateral Hou-San-Li acupoints for 0.5 h at 7 days and thereafter repeated every 3 days for 6 times. Goats in the Sham-A group were inserted with needles for 0.5 h at the aforementioned acupoints without any hand manipulation and electric stimulation. Visceromotor responses to colorectal distension, an indicator of VH, were recorded by electromyography. The terminal ileum and thoracic spinal cord (T₁₁) were sampled for evaluating ileitis at days 7 and 22, and distribution and expression-levels of PAR-2, CGRP and c-Fos on day 22. TNBS-treated-goats exhibited apparent transmural-ileitis on day 7, microscopically low-grade ileitis on day 22 and VH at days 7–22. Goats of Sham-A, VH or EA group showed higher (P < 0.01) VH at days 7–22 than the Control-goats. EA-treated goats exhibited lower (P < 0.01) VH as compared with Sham-A or VH group. Immunoreactive-cells and expression-levels of spinal PAR-2, CGRP and c-Fos in the EA group were greater (P < 0.01) than those in the Control group, but less (P < 0.01) than those in Sham-A and VH groups on day 22. Downregulation of spinal PAR-2 and CGRP levels by EA attenuates the ileitis and resultant VH.

Combined effect of laser acupuncture and electroacupuncture in knee osteoarthritis patients: A protocol for a randomized controlled trial

BACKGROUND

Knee osteoarthritis (KOA) is a common degenerative joint disorder that affects 250 million people globally. KOA can lead to disability and is often associated with cardiovascular disease, poor quality of life, and mortality. The most common treatment for KOA is non-steroidal anti-inflammatory drug administration. However, the analgesic effect is limited and often accompanied by multiple side effects. Hence, many KOA patients opt for complementary and alternative medicine. Acupuncture is one of the most popular complementary treatments with great analgesic effect and minimal side effect. Electroacupuncture (EA) and laser acupuncture (LA) have been known to reduce pain in KOA patients. However, to date, no study has assessed the benefits of combining these two therapies.

METHODS

Fifty participants diagnosed with KOA, aged 50 years or older, and with consistent knee pain for more than 3 months were recruited and randomly assigned to the treatment group (EA plus LA) or control group (EA plus sham LA without laser output). All subjects in the treatment group will undergo a combined EA and LA treatment thrice a week for 4 weeks. The acupuncture will be performed on GB33, GB34, SP9, SP10, and ST36 sites. The treatment group will receive acupuncture with a transcutaneous electrical nerve stimulator at GB33, GB34, SP9, and SP10 sites and with LA at EX-LE5, ST35, and BL40 sites. The subjects in the control group will undergo the same treatment modality as the treatment group, except these subjects will not be exposed to laser output. Outcome measurements will include visual analog scale, Western Ontario McMaster Universities Osteoarthritis Index, Knee injury and osteoarthritis outcome, body composition analysis, knee range of motion, quadriceps muscle stiffness, one-leg standing with eyes open test, and the 30-s chair stand test before and after 4 weeks of intervention.

OBJECTIVES

This protocol aims to investigate the combined effect of EA and LA in KOA patients.

The Mechanism of MAPK Signal Transduction Pathway Involved with Electroacupuncture Treatment for Different Diseases

The mitogen-activated protein kinase (MAPK) signal transduction pathway plays an important role in the regulation of various diseases, such as cardiovascular and cerebrovascular diseases, and takes part in anti-inflammatory effects, analgesic effects, protection against injury, and maintenance of gastrointestinal functions. Electroacupuncture therapy is an external therapy used in traditional Chinese medicine. By adding external electrical stimulation to traditional acupuncture, the stimulus gets doubled and the therapeutic efficacy gets enhanced accordingly. It combines the benefits of both acupuncture and electrical stimulation. In recent years, some studies have explored the molecular mechanisms of MAPK signal pathways involved with electroacupuncture treatment. Based on these recent studies, this article summarizes the mechanisms of MAPK signal transduction pathways involved with electroacupuncture treatment. This adds great value to the studies of molecular mechanisms of electroacupuncture treatment and also provides an effective reference for its clinical use.