Electroacupuncture alters pain-related behaviors and expression of spinal prostaglandin E 2 in a rat model of neuropathic pain

Head-to-Head Comparison of Electroacupuncture and Laser Acupuncture Effects on Autonomic Regulation and Clinical Effects in Dysmenorrhea: A Randomized Crossover Clinical Trial

Introduction: Electroacupuncture (EA) has been applied in dysmenorrhea and has shown good efficacy. The mechanisms of EA are associated with autonomic nervous system adjustments and neuroendocrine regulation. Laser acupuncture (LA), however, has been widely investigated for its noninvasiveness. However, it remains uncertain whether LA is as effective as EA. This study aimed to compare EA and LA head to head in dysmenorrhea. Methods: A crossover, randomized clinical trial was conducted. EA or LA was applied to selected acupuncture points. Participants were randomized into two sequence treatment groups who received either EA or LA twice per week in luteal phase for 3 months followed by 2-month washout, then shifted to other groups (sequence 1: EA > LA; sequence 2: LA > EA). Outcome measures were heart rate variability (HRV), prostaglandins (PGs), pain, and quality-of-life (QoL) assessment (QoL-SF12). We also compared the effect of EA and LA in low and high LF/HF (low frequency/high frequency) status. Results: Totally, 43 participants completed all treatments. Both EA and LA significantly improved HRV activity and were effective in reducing pain (Visual Analog Scale [VAS]; EA: p < 0.001 and LA: p = 0.010) and improving QoL (SF12: EA: p < 0.001, LA, p = 0.017); although without intergroup difference. EA reduced PGs significantly (p < 0.001; δ p = 0.068). In low LF/HF, EA had stronger effects than LA in increasing parasympathetic tone in respect of percentage of successive RR intervals that differ by more than 50 ms (pNN50; p = 0.053) and very low-frequency band (VLF; p = 0.035). Conclusion: There is no significant difference between EA and LA in improving autonomic nervous system dysfunction, pain, and QoL in dysmenorrhea. EA is prominent in PGs changing and preserving vagus tone in low LF/HF; yet LA is noninvasive for those who have needle phobia. Whether LA is equivalent with EA and the mechanism warrants further study. Clinical trial identification number: NCT04178226.

Efficacy and safety of therapies related to acupuncture for acute herpes zoster: A PRISMA systematic review and network meta-analysis

BACKGROUND

Herpes zoster (HZ) is mainly characterized by intense pain and severe skin lesions, particularly during the acute phase, which seriously affects the patient's quality of life. Acupuncture is a widely used and effective treatment for HZ. However, there are many types of acupuncture, which have different curative efficacy. This study employed a network meta-analysis (NMA) to assess and rank the clinical efficacy of different acupuncture therapies.

METHODS

The database of Cochrane Library, Web of Science, PubMed, MEDLINE, Embase, China National Knowledge Infrastructure (CNKI), Chinese BioMedical Database, VIP Database, and Wanfang Database were searched from inception to December 31, 2022 to identify eligible randomized controlled trials (RCTs) of acupuncture related therapies in the treatment of acute HZ. The outcome indicators measured were visual analogue scale (VAS), date of cessation of herpes increase (DCHI), effective rate (ER), postherpetic neuralgia (PHN), and adverse events (AEs). Bayesian network meta-analyses were performed using the GeMTC package (version 1.0-1) and R software (version 4.2.3).

RESULTS

A total of 59 RCTs with 3930 patients were included. The results of this NMA were as follows: compared with pharmacotherapy, electroacupuncture (EA) + pricking and cupping (PC) shown the best efficacy to improve VAS score and reduce DCHI. In terms of ER, EA + fire needle (FN) had the highest results of probability ranking. PC was more effective in reducing the incidence of PHN. Furthermore, this study shown that the incidence of AEs associated with acupuncture-related therapies was acceptable.

CONCLUSIONS

This study indicated that therapies related to acupuncture were both effective and safe in treating acute HZ, and could significantly reduce patients' symptoms such as pain and skin lesions with fewer adverse events. Clinically, the selection of the appropriate therapy should be based on practical considerations. However, due to the limitations of this study, more high-quality trials are required to evaluate the efficacy and safety of acupuncture-related therapy for the treatment of acute HZ.

The Role of Acupuncture and Its Related Mechanism in Treating Chronic Prostatitis/Chronic Pelvic Pain Syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is one of the most common diseases in urology, and its prevalence has been increasing, causing serious urogenital problems in men. Several targeted oral drug therapies exist to treat the pelvic pain experienced in this disease. However, these therapies may have potential adverse effects, and due to the unique location of the prostate, delivery of medications to the target lesion is difficult. Consequently, many patients seek alternative therapies. Acupuncture is a well-established treatment method in traditional Chinese medicine that can improve CP/CPPS symptoms and reduce pain. However, previous systematic reviews overlooked the significance of the characteristics and mechanisms of acupuncture therapy. This study aimed to summarize the characteristics and benefits of acupuncture therapy for CP/CPPS based on relevant literature and predict and analyze its related mechanisms.

Evaluation of electroacupuncture for symptom modification in a rodent model of spontaneous osteoarthritis

OBJECTIVE

Faced with the frustration of chronic discomfort and restricted mobility due to osteoarthritis (OA), many individuals have turned to acupuncture for relief. However, the efficacy of acupuncture for OA is uncertain, as much of the evidence is inconclusive. The purpose of this study was to evaluate electroacupuncture (EA) in a rodent model of OA such that conclusions regarding its effectiveness for symptom or disease modification could be drawn.

METHODS

Ten 12-month-old male Hartley guinea pigs-which characteristically have moderate to advanced OA at this age-were randomly assigned to receive EA for knee OA (n = 5) or anesthesia only (control group, n = 5). Treatments were performed three times weekly for 3 weeks, followed by euthanasia 2 weeks later. Gait analysis and enclosure monitoring were performed weekly to evaluate changes in movement. Serum was collected for inflammatory biomarker testing. Knee joints were collected for histology and gene expression.

RESULTS

Animals receiving EA had significantly greater changes in movement parameters compared to those receiving anesthesia only. There was a tendency toward decreased serum protein concentrations of complement component 3 (C3) in the EA group compared to the control group. Structural and antioxidant gene transcripts in articular cartilage were increased by EA. There was no significant difference in total joint histology scores between groups.

CONCLUSION

This study provides evidence that EA has a positive effect on symptom, but not disease, modification in a rodent model of OA. Further investigations into mechanistic pathways that may explain the efficacy of EA in this animal model are needed.

Electroacupuncture Inhibits Autophagy of Neuron Cells in Postherpetic Neuralgia by Increasing the Expression of miR-223-3p

Postherpetic neuralgia (PHN) is a complication of herpes zoster viral infection. Its main manifestations are continuous or intermittent burning-like and electroshock-like pain in the affected nerves. Electroacupuncture (EA) is widely used in clinical treatment and exerts effects in alleviating neuropathic pain. In this study, we investigated the effect and underlying mechanism of EA on PHN. Sprague-Dawley rats were treated with resiniferatoxin (RTX) to establish a PHN model and subjected to EA and/or miR-223-3p overexpression (OV) or interference. Mechanical withdrawal latency was measured as an indication of pain sensitivity. Hematoxylin-eosin staining and transmission electron microscopy were performed to observe neuron cell morphology and autophagic vacuoles, respectively. ELISA was performed to detect reactive oxygen species (ROS) production and the levels of tumor necrosis factor- (TNF-) α, inducible nitric oxide synthase (iNOS), interleukin- (IL-) 6, and IL-10. Changes in autophagy and apoptosis-related miRNAs were detected by immunofluorescence and qRT-PCR, respectively. In RTX-treated rats, OV and EA reduced pain sensitivity, decreased the number of eosinophils, and increased that of nerve cells. ROS generation and the levels of TNF-α and iNOS were significantly reduced, while those of IL-6 and IL-10 were increased. OV and EA induced fewer autophagic vacuoles than those in the model group. The expression of autophagy-related protein microtubule-associated protein 1 light chain 3-II, ATG9, and Rab1 was decreased by OV and EA, whereas that of P62 was increased. qRT-PCR revealed that miR-223-3p expression in the model group decreased but was increased by EA. EA inhibits neuron cell autophagy in PHN by increasing miR-223-3p expression.

The Effect of Transcutaneous Electrical Acupoint Stimulation on Postoperative Catheter-Related Bladder Discomfort in Patients Undergoing Transurethral Resection of the Prostate

Background

Catheter-related bladder discomfort (CRBD), an extremely distressing complication secondary to an indwelling urinary catheterization, is frequently reported in patients with transurethral resection of the prostate (TURP), postoperatively. A prospective, randomized, controlled, double-blind study was designed to assess the efficacy of transcutaneous electrical acupoint stimulation (TEAS) as a treatment for CRBD in patients undergoing TURP.

Methods

Seventy benign prostatic hyperplasia male patients undergoing TURP under general anesthesia requiring intraoperative urinary catheterization were enrolled for the trial. An experienced acupuncturist performed TEAS for 30 minutes before general anesthesia with acupoints RN7, RN6, RN5, RN4, and RN3 and bilateral BL32, BL33, and BL34. Mean arterial pressure (MAP), heart rate (HR), oxygen saturation (SPO2), body temperature (T), and blood samples were collected during the surgery. A series of assessments included the incidence and severity of CRBD, postoperative pain, nausea and vomiting, and physical and mental state measurements.

Results

The incidence of CRBD was significantly lower in TEAS group than in control group at the time T5 [9(26%) vs. 28(80%), P < 0.001], T9 [20(57%) vs. 28(80%), P=0.039], T11 [7(20%) vs. 31(89%), P < 0.001], and T12 [4(11%) vs. 7(20%), P=0.003]. The severity of CRBD was significantly lower in TEAS group than in control group at the time T5 [0 vs. 10 (29%), P < 0.001], T9 [2(6%) vs. 10(29%), P=0.011], and T11 [0 vs .9(26%), P=0.002]. The QoR-40 total score was higher in TEAS group at time T11 [191.7(4.4) vs. 189.1(4.3), P=0.007] and T12 [195.3(1.9) vs. 193.3(3.0), P < 0.001]. The postoperative analgesia requirement was higher in control group [5.0(2.9) vs. 3.8(1.9), P=0.045].

Conclusions

TEAS could significantly prevent the incidence and severity of CRBD, reduce the postoperative analgesic requirement in the early postoperative period, and promote the quality of early recovery in patients undergoing TURP.

Electroacupuncture effects on the P2X4R pathway in microglia regulating the excitability of neurons in the substantia gelatinosa region of rats with spinal nerve ligation

Electroacupuncture (EA) has been used to treat neuropathic pain induced by peripheral nerve injury (PNI) by applying an electrical current to acupoints with acupuncture needles. However, the mechanisms by which EA treats pain remain indistinct. High P2X4 receptor (P2X4R) expression levels demonstrate a notable increase in hyperactive microglia in the ipsilateral spinal dorsal horn following PNI. In order to demonstrate the possibility that EA analgesia is mediated in part by P2X4R in hyperactive microglia, the present study performed mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) tests in male Sprague-Dawley rats that had undergone spinal nerve ligation (SNL). The expression levels of spinal P2X4R were determined using reverse transcription-quantitative PCR, western blotting analysis and immunofluorescence staining. Furthermore, spontaneous excitatory postsynaptic currents (sEPSCs) were recorded using whole-cell patch clamp to demonstrate the effect of EA on synaptic transmission in rat spinal substantia gelatinosa (SG) neurons. The results of the present study demonstrated that EA increased the MWT and TWL and decreased overexpression of P2X4R in hyperactive microglia in SNL rats. Moreover, EA attenuated the frequency of sEPSCs in SG neurons in SNL rats. The results of the present study indicate that EA may mediate P2X4R in hyperactive spinal microglia to inhibit nociceptive transmission of SG neurons, thus relieving pain in SNL rats.

Zishen Huoxue Recipe Protecting Mitochondrial Function of Hypoxic/Reoxygenated Myocardial Cells through mTORC1 Signaling Pathway

Objective

This study focuses on the role of Zishen Huoxue Decoction (ZSHX) in reducing mitochondrial membrane potential and reducing the proportion of apoptosis through the mTORC1 signaling pathway.

Methods

In our experiment, we first constructed an in vitro hypoxia/reoxygenation (H/R) model of H9C2 cells. Then, the cells were divided into control group, model group (hypoxia/reoxygenation, H/R), ZSHX, ZSHX + Rapa, low-dose ZSHX (100 μg/ml), and middle-dose ZSHX. High-dose ZSHX (400 μg/ml) group was treated with Zishen Huoxue Decoction (ZSHX). Western Blot was used to detect the expression of cell-related protein and RT-PCR was used to detect the expression of the cell-related gene in each group. Flow cytometry was used to assay for ROS content and the apoptotic ratio of H9C2 cells, Seahorse Live Cell Energy Meter was used to detect the Mitochondrial Respiratory Function in H9C2 Cells, and confocal laser scanning was used to detect the mitochondrial membrane potential of H9C2 cells.

Results

Western Blot assay showed that the relative expression of mTOR and Raptor in the H/R group was significantly lower than that in the control group (n = 3, P < 0.05). The expression of mTOR and Raptor was upregulated and the relative expression of 4E-BP1 was downregulated in the middle- and high-dose ZSHX groups (n = 3, P < 0.05). In addition, the ROS content of H9C2 cells was detected by flow cytometry, showing the ROS synthesis in H/R group (78.31 + 6.14) higher than that in the control group (34.53 + 6.10) (n = 3, P < 0.01). The ROS value was increased significantly after rapamycin inhibited mTOR (66.18 (+4.03 vs. 52.31 (+6.01), n = 3, P < 0.05). The basal mitochondrial respiration and ATP production in H/R group were significantly lower than those in the control group (38.17 + 17.76); the mitochondrial leakage in H/R model group was significantly higher than that in the control group (H/R: 40.93 + 5.18 vs. Ctrl: 27.17 + 8.92, n = 4, P < 0.05). The apoptotic rate of cardiomyocytes in the H/R model group (70.91 + 4.57) was significantly higher than that in the control group (14.52 + 2.37, n = 3, P < 0.01), and Zishen Huoxue Decoction could decrease the apoptotic rate of hypoxic-reoxygenated cardiomyocytes (ZSHX: 18.24 + 4.17 vs. H/R: 78.91 + 3.48, n = 3, P < 0.01).

Conclusion

ZSHX Decoction has the effects of activating mTORC1, inhibiting the overexpression of 4E-BP1, inhibiting fatty acid oxidation, protecting the respiratory function of mitochondria, reducing ROS and apoptosis, and thus protecting myocardial cells from injury.

Electroacupuncture-Related Metabolic Brain Connectivity in Neuropathic Pain due to Brachial Plexus Avulsion Injury in Rats

Objective: The present study aimed to investigate the analgesic effect of electroacupuncture (EA) in neuropathic pain due to brachial plexus avulsion injury (BPAI) and related changes in the metabolic brain connectivity. Methods: Neuropathic pain model due to BPAI was established in adult female Sprague-Dawley rats. EA stimulations (2/15 Hz, 30 min/day, 5-day intervention followed by 2-day rest in each session) were applied to the fifth-seventh cervical "Jiaji" acupoints on the noninjured side from 1st to 12th weeks following BPAI (EA group, n = 8). Three control groups included sham EA (nonelectrical acupuncture applied to 3 mm lateral to the real "Jiaji" acupoints), BPAI-only, and normal rats (no particular intervention; eight rats in each group). Thermal withdrawal latency (TWL) of the noninjured forepaw was regularly tested to evaluate the threshold of thermalgesia. Small animal [fluorine-18]-fluoro-2-deoxy-_D-glucose (¹⁸F-FDG) PET/CT scans of brain were conducted at the end of 4th, 12th, and 16th weeks to explore metabolic alterations of brain. Results: In the EA group, the TWL of the noninjured forepaw significantly decreased following BPAI and then increased following EA stimulation, compared with sham EA (P < 0.001). The metabolic brain connectivity among somatosensory cortex (SC), motor cortex (MC), caudate putamen (Cpu), and dorsolateral thalamus (DLT) in bilateral hemispheres decreased throughout the 16 weeks' observation in the BPAI-only group, compared with the normal rats (P < 0.05). In the EA group, the strength of connectivity among the above regions were found to be increased at the end of 4th week following BPAI modeling, decreased at 12th week, and then increased again at 16th week (P < 0.05). The changes in metabolic connectivity were uncharacteristic and dispersed in the sham EA group. Conclusion: The study revealed long-term and extensive changes of metabolic brain connectivity in EA-treated BPAI-induced neuropathic pain rats. Bilateral sensorimotor and pain-related brain regions were mainly involved in this process. It indicated that modulation of brain metabolic connectivity might be an important mechanism of analgesic effect in EA stimulation for the treatment of neuropathic pain.

Electroacupuncture for pain relief in labour inhibits spinal p38 MAPK-mediated prostaglandin E2 release and uterine prostaglandin E2 receptor expression in rats

BACKGROUND

p38 mitogen-activated protein kinase (p38 MAPK) activation involves the release of prostaglandin E2 (PGE2) and hyperalgesia. We have previously reported that electroacupuncture (EA) relieves labour pain, but the potential mechanisms remain unclear.

OBJECTIVE

To observe the effects of EA on labour pain intensity, serum PGE2 levels and the p38 MAPK signalling pathway in rats during labour.

METHODS

Female rats copulated with male rats to induce pregnancy, and then received castor oil to trigger labour. During labour, rats remained untreated (Control group, n=30) or were treated with remifentanil (n=30) or EA at Jiaji (n=30) or SP6+LI4 (n=30), respectively. The warm water tail-flick test was used to assess labour pain. Serum PGE2 levels were measured by ELISA. Protein expression of prostaglandin E2 receptor (PGER2), p38 MAPK and phospholipase A2 (PLA2) were analysed by Western blotting, and mRNA levels were measured by real-time PCR.

RESULTS

EA treatment at Jiaji or SP6+LI4 significantly relieved labour pain, decreased serum PGE2 levels and inhibited protein and gene expression of PGER2 in the myometrium. Moreover, EA reduced protein expression of PLA2 and p38 MAPK, and inhibited phosphorylation of p38 MAPK in the lumbar spinal cord but not in the cerebral grey matter. Additionally, EA markedly decreased mRNA levels of p38 MAPK in the lumbar spinal cord and significantly reduced PLA2-IV mRNA levels in both the lumbar spinal cord and cerebral grey matter.

CONCLUSIONS

This study indicates that EA relieves labour pain through, at least in part, inhibition of spinal p38 MAPK-mediated PGE2 release and uterine PGER2 expression in rats.

A rat model for studying electroacupuncture analgesia on acute visceral hyperalgesia

The aim of this study was to establish an appropriate rat model to study the effect of electroacupuncture (EA) analgesia on acute visceral hyperalgesia. Adult rats received colorectal instillation with different concentrations of acetic acid (AA). Treatment with EA was performed for 30 min at bilateral acupoints of ST-36 and ST-37 in the hind limbs. The visceral sensation of all rats was quantified by scores of abdominal withdrawal reflex (AWR) and discharges of rectus abdominis electromyogram (EMG) in response to colorectal distension (CRD). Two hours after instillation of saline (no AA), 1%, 2%, and 4% AA, there were no, slight, moderate and severe visceral hyperalgesia, respectively. Application of EA significantly relieved the visceral hyperalgesia induced by 2% but not 4% AA. The results suggest that 2% AA acute visceral hyperalgesia in adult rats responds well to EA treatment. This may offer an appropriate model for the investigation of EA effects.