Electroacupuncture decreases the leukocyte infiltration to white adipose tissue and attenuates inflammatory response in high fat diet-induced obesity rats

Comprehensive landscape-style investigation of the molecular mechanism of acupuncture at ST36 single acupoint on different systemic diseases

The principle of acupoint stimulation efficacy is based on traditional meridian theory. However, the molecular mechanisms underlying the therapeutic effects of acupoints in treating diseases remain unclear in modern scientific understanding. In this study, we selected the ST36 acupoint for investigation and summarized all relevant literature from the PubMed database over the past 10 years. The results indicate that stimulation of ST36 single acupoints has therapeutic effects mainly in models of respiratory, neurological, digestive, endocrine and immune system diseases. And it can affect the inflammatory state, oxidative stress, respiratory mucus secretion, intestinal flora, immune cell function, neurotransmitter transmission, hormone secretion, the network of Interstitial Cells of Cajal (ICC) and glucose metabolism of the organism in these pathological states. Among them, acupuncture at the ST36 single point has the most prominent function in regulating the inflammatory state, which can mainly affect the activation of MAPK signaling pathway and drive the "molecular-cellular" mode involving macrophages, T-lymphocytes, mast cells (MCs) and neuroglial cells as the core to trigger the molecular level changes of the acupuncture point locally or in the target organ tissues, thereby establishing a multi-system, multi-target, multi-level molecular regulating mechanism. This article provides a comprehensive summary and discussion of the molecular mechanisms and effects of acupuncture at the ST36 acupoint, laying the groundwork for future in-depth research on acupuncture point theory.

Acupuncture as multi-targeted therapy for the multifactorial disease obesity: a complex neuro-endocrine-immune interplay

The prevalence of obesity has reached pandemic dimensions. It is associated with multiple comorbidities and is becoming a clinical and public health threat. Obesity is a multifactorial disease with a complex pathophysiology and interplay of various systems. A strong interplay exists between the neuro-endocrine system, the immune system with systemic chronic low-grade inflammation, and microbiome dysbiosis that can lead to the development of obesity, which in turn can exacerbate each of these factors, hence creating a vicious cycle. The conventional treatment with lifestyle modifications such as diet, physical exercise, pharmacotherapy, and bariatric surgery does not always result in sufficient weight control thus paving the way for other strategies. As one such strategy, acupuncture is increasingly used worldwide to treat obesity. This narrative review outlines the evidence for this neuro-endocrine-immune interplay in the pathophysiology of obesity. Furthermore, the existing experimental and clinical evidence of acupuncture as a multi-targeted therapy for obesity is explained and future research perspectives are discussed.

Electroacupuncture relieves portal hypertension by improving vascular angiogenesis and linking gut microbiota in bile duct ligation rats

The pathological increase in the intrahepatic resistance and decrease peripheral vascular tone in the development of portal hypertension (PHT). PHT has been linked to lower microbial diversity and weakened intestinal barrier, and interplay alters inflammatory signaling cascades. Electroacupuncture (EA) may ameliorate the inflammatory response and limit arterial vasodilatation and portal pressure. This study addresses the possible mechanisms underlying putative hemodynamics effects of EA in PHT rats. PHT was induced by bile duct ligation (BDL) over 7 days in rats. BDL rats were treated with low-frequency EA (2 Hz) at acupoint, ST36, 10 min once daily for 7 consecutive days. EA significantly reduced portal pressure and enhanced maximum contractile responses in the aorta, and blunts the angiogenesis cascade in PHT rats. EA decreased the aortic angiogenesis signaling cascade, reflected by downregulated of ICAM1, VCAM1, VEGFR1, and TGFβR2 levels. In addition, EA preserved claudin-1, occludin, and ZO-1 levels in BDL-induced PHT model. Furthermore, EA demonstrates to have a positive effect on the gut Bacteroidetes/Firmicutes ratio and to reduce pro-inflammatory cytokines and endotoxins. These results summarize the potential role of EA in the gut microbiota could potentially lead to attenuate intestine injury which could further contribute to vascular reactivity in PHT rats.

Chronic intermittent hypobaric hypoxia ameliorates vascular reactivity through upregulating adiponectin expression of PVAT in metabolic syndrome rats

Cumulating evidence demonstrated that chronic intermittent hypobaric hypoxia (CIHH) had beneficial effects on the body. This study investigated the role of perivascular adipose tissue (PVAT) in ameliorating effect of CIHH on vascular reactivity by adiponectin in mesenteric artery of metabolic syndrome (MS) rats. Main methods: 6-week-old male Sprague-Dawley rats were randomly divided into four groups: control (CON), MS model, CIHH treatment, and MS + CIHH treatment group. The size of adipocytes in PVAT was measured by scanning electron microscopy. Serum adiponectin was measured. The microvessel recording technique was used to observe the effect of CIHH on contraction and relaxation in mesenteric artery rings. Also, the expressions of interleukin-1β, tumor necrosis factor-α, adiponectin, AdipoR1, AdipoR2, APPL1, and endothelial nitric oxide synthase (eNOS) were assayed by Western blotting. Key findings: in MS rats, adipocyte size increased, serum adiponectin decreased, contraction reaction increased while relaxation reaction decreased, the expression of pro-inflammatory cytokines was upregulated, while adiponectin was downregulated in PVAT, and the expressions of AdipoR1, AdipoR2, APPL, and phosphorylated-eNOS were downregulated in mesenteric artery. All aforementioned abnormalities of MS were ameliorated in MS + CIHH rats. We concluded that CIHH treatment improves vascular reactivity through upregulating adiponectin expression and downregulating pro-inflammatory cytokine expression of PVAT in MS rats.

Imperatorin Improves Obesity-Induced Cardiac Sympathetic Nerve Injury Mediated by P2X4 Receptor in Stellate Sympathetic Ganglion

Obesity can activate the inflammatory signal pathway, induce in the body a state of chronic inflammation, and increase the excitability of the sympathetic nervous system, which may induce sympathetic neuropathic injury. The stellate sympathetic ganglia (SG) can express the P2X4 receptor, and the abnormal expression of the P2X4 receptor is related to inflammation. Imperatorin (IMP) is a kind of furan coumarin plant which has anti-inflammatory effects. This project aimed to investigate whether IMP can affect the expression of P2X4 receptors in the SG of obese rats to display a protective effect from high-fat-triggered cardiac sympathetic neuropathic injury. Molecular docking through homology modelling revealed that IMP had good affinity for the P2X4 receptor. Our results showed that compared with the normal group, the administration of IMP or P2X4 shRNA decreased sympathetic excitement; reduced the serum levels of triglyceride, total cholesterol, and lactate dehydrogenase; downregulated the expression of P2X4 receptors in SG; and inhibited the expression of inflammatory factors in the SG and serum of obese rats significantly. In addition, the expression of factors associated with the cell pyroptosis GSDMD, caspase-1, NLRP-3, and IL-18 in obese rats were significantly higher than those of the normal rats, and such effects were decreased after treatment with IMP or P2X4 shRNA. Furthermore, IMP significantly reduced the ATP-activated currents in HEK293 cells transfected with P2X4 receptor. Thus, the P2X4 receptor may be a key target for the treatment of obesity-induced cardiac sympathetic excitement. IMP can improve obesity-induced cardiac sympathetic excitement, and its mechanism of action may be related to the inhibition of P2X4 receptor expression and activity in the SG, suppression of cellular pyroptosis in the SG, and reduction of inflammatory factor levels.

Anti-Inflammatory Effects of Acupuncture at ST36 Point: A Literature Review in Animal Studies

So far, a number of acupuncture studies have shown anti-inflammatory effects of acupuncture treatment, mostly known at specific point ST36. However, there is no literature that oversaw the inflammation-regulatory effects of acupuncture in each tissue. Therefore, we investigated how acupuncture at specific acupoint ST36 regulates inflammation and its underlying mechanisms. We searched literatures on PubMed until July 2021 using the keywords “animal, acupuncture, ST36, inflammation, immune,” and 292 literatures were searched. We ultimately selected 69 studies to determine the anti-inflammatory actions of acupuncture at ST36 and classified the changes of inflammatory mediators according to target regions. Forty-three studies were included in body fluids, 27 studies in the digestive system, 17 studies in the nervous system, and 30 studies in other tissues or organs. In this review, we found that acupuncture at ST36 has clinical benefits in relieving inflammation through several mechanisms such as vagus nerve activation, toll-like receptor 4 (TLR4)/NF-κB signaling, macrophage polarization, mitogen-activated protein kinase (MAPK) signaling pathway, and cholinergic anti-inflammatory pathway. We expect that these data will inform further studies related to ST36 acupuncture on inflammation.

Electroacupuncture Stimulation Regulates Adipose Lipolysis via Catecholamine Signaling Mediated by NLRP3 Suppression in Obese Rats

Chronic low-grade inflammation of visceral adipose tissue can cause obesity-associated insulin resistance, leading to metabolic syndrome. However, anti-inflammatory drugs and those for obesity management can lead to serious side effects such as abnormal heart rate and blood pressure. Consequently, this study aimed to explore the therapeutic potential of electroacupuncture stimulation (ES) for obesity and associated chronic inflammation. Sprague-Dawley male rats were fed a high-fat diet (HFD) for ten weeks to build an obesity model, and half of the diet-induced obesity (DIO) rats were received ES. The levels of inflammatory factors were detected by ELISA and qPCR analysis. The nerve-associated macrophages were marked with immunofluorescence staining. The molecular mechanism of NLRP3 inflammasome in ES was determined by the NLRP3 inflammasome activation model. Compared to HDF rats, ES showed decreased body weight and chronic inflammatory damage. Specifically, this occurred via a decrease in monoamine oxidase-A (MAOA) expression, which suppressed noradrenaline degradation. MAOA is expressed in nerve-associated macrophages (NAMs), and ES attenuated NAMs by suppressing the NLRP3 inflammasome. The NLRP3 agonist blocked the noradrenaline degradation-reducing effect of ES, and an increase in lipolysis via the inhibition of the NLRP3 inflammasome attenuated NAMs. Thus, our findings suggest that ES induced lipolysis via activation of the NLRP3 inflammasome in nerve-associated macrophages (NAMs), independently of sympathetic nervous system activity.

Obesity Animal Models for Acupuncture and Related Therapy Research Studies

Obesity and related diseases are considered as pandemic representing a worldwide threat for health. Animal models are critical to validate the effects and understand the mechanisms related to classical or innovative preventive and therapeutic strategies. It is, therefore, important to identify the best animal models for translational research, using different evaluation criteria such as the face, construct, and predictive validity. Because the pharmacological treatments and surgical interventions currently used for treating obesity often present many undesirable side effects, relatively high relapse probabilities, acupuncture, electroacupuncture (EA), and related therapies have gained more popularity and attention. Many kinds of experimental animal models have been used for obesity research studies, but in the context of acupuncture, most of the studies were performed in rodent obesity models. Though, are these obesity rodent models really the best for acupuncture or related therapies research studies? In this study, we review different obesity animal models that have been used over the past 10 years for acupuncture and EA research studies. We present their respective advantages, disadvantages, and specific constraints. With the development of research on acupuncture and EA and the increasing interest regarding these approaches, proper animal models are critical for preclinical studies aiming at developing future clinical trials in the human. The aim of the present study is to provide researchers with information and guidance related to the preclinical models that are currently available to investigate the outcomes of acupuncture and related therapies.

The Role of Electroacupuncture in the Regulation of Appetite-Controlling Hormone and Inflammatory Response in Obesity

Objective: Obesity, a condition with serious complications, needs special attention. It is a complex and multifactorial problem and regulation of calorie balance involving various humoral and central factors is the main key for managing obesity. In addition, there is an increase in various proinflammatory cytokines and an increase in oxidative stress. There is a need to discover a useful therapy for obesity management. The goal of this review was to examine the literature on electroacupuncture (EA) as a potential therapy. Methods: This review explores the literature on EA, which has proven to be effective for inducing weight loss in experimental human and animal studies. Both continuous and dense-disperse EA waves have their own roles in hormone regulation of obesity using ST 25, CV 9, CV 12, CV 4, SP 6, ST 36, and ST 44; this is discussed the associated mechanism related to this is through suppression of various orexigenic peptides, enhancement of anorexigenic peptides, suppression of inflammatory factors, and improvement in the balance of pro-oxidants and antioxidants. Conclusions: The absence of another definitive therapy for obesity and EA's minimal side-effects make it a potential therapy for managing obesity.

Electroacupuncture Prevents Osteoarthritis of High-Fat Diet-Induced Obese Rats

The effects of acupuncture on osteoarthritis (OA) pathogenesis have been demonstrated in vitro and in animal models. However, the potential for acupuncture to mediate protective effects on obese-induced OA has not been examined. Here, we investigated the effects of different acupuncture patterns on OA pathogenesis in high-fat diet- (HFD-) induced obese rats. After 12-week diet-induced obesity, obese rats were treated with three acupuncture protocols for 2 weeks, including ST36, GB34, and ST36+GB34. The results showed that the three acupuncture protocols both prevented obesity-induced cartilage matrix degradation and MMP expression and mitigated obesity-induced systemic and local inflammation but had different regulatory effects on lipid metabolism and gut microbiota disorder of obese-induced OA rats. Furthermore, the three acupuncture protocols increased the microbial diversity and altered the structure of community of feces in obese rats. We found that ST36 and GB34 could inhibit proinflammatory shift in the gut microbiome with an increase in the ratio of Bacteroidetes/Firmicutes and promote the recovery of relative abundance of Clostridium, Akkermansia, Butyricimonas, and Lactococcus. Although both ST36 and GB34 had an anti-inflammatory effect on serum inflammatory mediators, only the acupuncture protocol with both ST36 and GB34 could effectively inhibit LPS-mediated joint inflammation in obesity rats. Therefore, relieving obesity-related chronic inflammation, lipid metabolism disorder, and gut microbiota disorder may be an important mechanism for acupuncture with ST36 and GB34 to promote OA recovery.

Effectiveness of Acupuncture in Treatment of Simple Obesity in Animal Models: A Systematic Review and Meta-Analysis

BACKGROUND

Simple obesity has become a global risk to health of human beings. Acupuncture, as one of traditional Chinese medicine therapies, has been widely used in obesity treatment in recent years. However, the individual heterogeneity which makes acupuncture's efficiency unstable leads to some controversy. So more evidence-based results are necessary to judge the effectiveness of acupuncture in treatment of simple obesity. Compared with clinical trials, animal experiments are controllable, and the underlying mechanism is more likely to be explored. Last but not the least, more and more experimental studies on acupuncture for animal obesity have been published. Therefore, we conducted the systematic review and meta-analysis to evaluate the effectiveness of acupuncture in treating simple obesity in animal experiments.

METHODS

Randomized Controlled Trials (RCTs) on acupuncture for simple obesity animal models were searched from six databases: PubMed, MEDLINE, CNKI, VIP, WanFang Date, and CMB from inception to February 2017 and updated on April 12, 2019. RevMan 5.3 software was used for meta-analysis. Treatment effects were summarized as relative risk (RR) and Standard mean difference (SMD) with 95% of confidence interval (CI).

RESULTS

A total of 108 trials involving 5731 rats were included. Meta-analysis showed that acupuncture had better effect on reducing weight (SMD -2.60, 95%CI: -2.93 to -2.26, p<0.00001) and Lee's index (SMD -2.62, 95%CI:-3.18 to -2.06, p<0.00001) compared with control group. However, the methodological quality of included studies was generally poor. Details of blinding were not reported in most studies. In spite of high heterogeneity being observed on the merged data, sensitivity analysis using the leave-one-out approach, subgroup analysis based on different acupuncture techniques, and rat strains and meta-regression all failed to find the sources of heterogeneity. The asymmetric funnel plot suggested publication bias. Besides, adverse events were not reported in any reports.

CONCLUSIONS

Our review provided positive evidence of acupuncture for simple obesity. Unfortunately, none of the firm conclusions can be drawn due to methodological flaws, high heterogeneity, and publication bias. More high-quality trials are needed in future to get objective conclusions.

Mechanisms of Acupuncture Therapy for Simple Obesity: An Evidence-Based Review of Clinical and Animal Studies on Simple Obesity

Simple obesity is a worldwide epidemic associated with rapidly growing morbidity and mortality which imposes an enormous burden on individual and public health. As a part of Traditional Chinese Medicine (TCM), acupuncture has shown the positive efficacy in the management of simple obesity. In this article, we comprehensively review the clinical and animal studies that demonstrated the potential mechanisms of acupuncture treatment for simple obesity. Clinical studies suggested that acupuncture regulates endocrine system, promotes digestion, attenuates oxidative stress, and modulates relevant molecules of metabolism in patients of simple obesity. Evidence from laboratory indicated that acupuncture regulates lipid metabolism, modulates inflammatory responses, and promotes white adipose tissue browning. Acupuncture also suppresses appetite through regulating appetite regulatory hormones and the downstream signaling pathway. The evidence from clinical and animal studies indicates that acupuncture induces multifaceted regulation through complex mechanisms and moreover a single factor may not be enough to explain the beneficial effects against simple obesity.

Electroacupuncture Reduces Body Weight by Regulating Fat Browning-Related Proteins of Adipose Tissue in HFD-Induced Obese Mice

Objective: This study investigated the influence of electroacupuncture (EA) and its potential underlying mechanisms on adipose tissue in obese mice. Methods: Three-week-old male C56BL/6 mice were randomly divided to feed or not to feed high-fat diet (HFD), named HFD group and chow diet (CD) group, respectively. After 12 weeks, CD and HFD mice were randomly divided into two groups, respectively, to receive or not receive EA for 4 weeks. Body weight (BW) was monitored. Intraperitoneal glucose tolerance test and metabolic chamber recordings were performed. Blood samples and adipose tissue were collected for the analysis of leptin, triglyceride levels, and fat browning-related proteins. Results: EA significantly reduced food intake, BW, and white adipose tissue (WAT)/BW ratio; decreased the adipocyte size and serum concentrations of triglyceride (TG) and cholesterol; and increased oxygen consumption in HFD mice. Compared with the CD mice, the HFD mice had elevated fasting serum glucose level and impaired glucose tolerance; however, these parameters were decreased by EA treatment. Meanwhile, EA promoted the protein and mRNA expressions of UCP1, PRDM16, and PGC-1α in adipose tissue, and activated sympathetic nerves via p-TH, A2AR, and β3AR in white adipose tissue. Conclusions: EA reduced food intake, BW, TG, and cholesterol, and improved glucose tolerance in HFD mice. This ameliorative effect of EA on obesity-related symptoms associated with its promoted adipose tissue plasticity via activating sympathetic nerves.

Clinical efficacy of acupoint embedment in weight control: A systematic review and meta-analysis

INTRODUCTION

Acupoint embedment, a modified acupuncture technique, is gaining its popularity in weight control in adult obesity or overweight nowadays. The objective of this study was to investigate the clinical efficacy of acupoint embedment in weight control of adult obesity or overweight by systematically assess available randomized controlled trials (RCTs) and analyze the integrated findings. A total of 529 literatures were initially searched from the databases. Five RCTs in assessing the effect of acupoint embedment versus sham control group were identified.

RESULTS

A total of 219 subjects in the intervention group and 206 subjects in the control group from 5 eligible studies were eventually included in this meta-analysis. Mean body mass index (BMI) decreased 0.94 kg/m (95% confidence interval [CI]: -1.56 to -0.32, P = .003) more in acupoint embedment group than the sham control group. Meanwhile, subjects received acupoint embedment had 2.97 kg (95% CI: -4.44 to -1.49, P < .0001) decrease in mean body weight more than in sham control group. Both parameters were statistically significant. Adverse events including bruise, soreness and cramp, patchy skin induration, erythema were reported, yet none involved hospitalization or mortality. Interestingly, stomach meridian and spleen meridian involved in all 5 studies.

CONCLUSION

This meta-analysis showed that acupoint embedment was more effective in weight control than the sham control group. Together with its convenience and low cost, acupoint embedment may be considered as an alternative treatment in weight control.

Genome-wide regulation of electro-acupuncture on the neural Stat5-loss-induced obese mice

Acupuncture is reported to be effective in treating obesity related illnesses, but its mechanism is still unclear. To investigate this mechanism we applied electro-acupuncture (EA) in a mouse model of obesity and used RNA-seq to identify molecular consequences. Deletion of the transcription factor STAT5 from neurons (Stat5NKO) led to obesity. Acupuncture, in turn, reduced body weight and the ratio of epididymal white adipose tissue (Epi-WAT) to body weight, and it also decreased plasma concentrations of glucose, triglyceride, and cholesterol. In addition, EA increased cold endurance of Stat5NKO obese mice. EA reversed altered gene expressions in the hypothalamus and Epi-WAT, especially in the hypothalamus in Stat5NKO obese mice. This study provides, for the first time, insight into genomic networks of obesity and their modulation by electro-acupuncture, which in turn reveals potential mechanisms that explain acupuncture-induced weight-loss.

Electroacupuncture prevents white adipose tissue inflammation through modulation of hypoxia-inducible factors-1α-dependent pathway in obese mice

BACKGROUND

Electroacupuncture (EA) shows anti-inflammation and several pleiotropic effects that interact with metabolic pathways. In the present study we tested the hypothesis that EA prevents inflammatory response and weight gain in obese mice through modulation of hypoxia-inducible factors-1α (HIF1-α)-dependent pathways in white adipose tissues.

METHODS

Mice were divided in 4 groups: Non-obese, ob/ob, ob/ob submitted to 3 treatments, ob/ob submitted to 7 treatments. Low-frequency EA (2 Hz) was applied at the Zusanli (ST36) acupoint 10 min three times weekly for one or two consecutive weeks in male ob/ob mice. At 22 weeks of age, plasma lipid, glucose, other metabolites and relevant markers were measured by standard assays. Adipose tissue was assessed with immunohistochemical staining. Adipose tissue extracts were also analyzed with quantitative real-time polymerase chain reaction (Q-PCR) and Western blotting.

RESULTS

EA treatment is associated with decreased adipose tissue inflammation, and markedly decreased fat mass and adipocyte size in ob/ob mice. In obese mice, The protein levels of HIF-α were increased, EA shown a marked trend in inhibiting the hypoxic response in adipose tissue. The expression level of hypoxia-related genes (vascular endothelial growth factor A, VEGFA; glucose transporter type 1, Slc2al; glutathione peroxidase 1, GPX1) and inflammation-related genes (TNF-α, IL-6, MCP-1) expression were also reduced in adipose tissue after EA treatment. EA treatment decreased the macrophage recruitment and infiltration (F4/80), and in addition we found that decrease in NF-κB and increase in IkBα were both correlated to reduction in inflammatory processes in adipose tissue. This phenomenon was paralleled by the decrease in the levels of inflammatory cytokines, such as TNF-α, IL-6 and IL-1β in obese mice.

CONCLUSIONS

We conclude that EA prevents weight gain through modulation of HIF-1α-dependent pathways and inflammatory response in obese adipose tissues.

Comparative effectiveness of electro-acupuncture plus lifestyle modification treatment for patients with simple obesity and overweight: study protocol for a randomized controlled trial

BACKGROUND

Acupuncture is considered to be an effective and safe treatment for obese and overweight patients, although high-quality evidence regarding the effects of acupuncture on obesity are not conclusive. The aim of the current study is to investigate the effectiveness of electro-acupuncture plus lifestyle modification for treating obese and overweight patients, in comparison with lifestyle modification alone in China.

METHODS/DESIGN

To compare the effectiveness of acupuncture plus lifestyle modification, a 2-armed, controlled trial with randomization using minimization will be conducted on 150 simple obesity and overweight patients, aged 18-50 years, for a 36-week study duration. All patients will be randomly assigned to one of two groups and will receive either acupuncture plus lifestyle modification or lifestyle modification alone. Outcomes will be evaluated at baseline and at 4 weeks, 8 weeks, and 12 weeks during treatment as well as at 6-week, 12-week, and 24-week follow-up. The primary endpoint is change of body mass index (BMI) during the 12th week. Secondary endpoints are body weight; waist-to-hip ratio; biochemical tests including serum cholesterol (TC), triglyceride (TG) and high-density lipoprotein (HDL) levels; and answers to the Short Form 36 (SF-36) and the Impact of Weight on Quality of Life Questionnaire-Lite Version (IWQOL-Lite). Statistical analyses will be based on the intention-to-treat (ITT) principle. The main endpoint will be analyzed by analysis of covariance (ANCOVA), and the objective outcome results will be analyzed by logistic regression analysis. To avoid potential confounding factors, additional sensitivity analyses will be conducted following these statistical analyses.

DISCUSSION

This trial is the first to compare the effectiveness of acupuncture plus lifestyle modification for treating obesity relative to lifestyle modification treatment alone by using a pragmatic study design. We hope that the results of this study will contribute to advancing the current methodology of acupuncture trials for obesity and will facilitate the application of useful acupuncture strategies in real-world clinical settings.

TRIAL REGISTRATION

ChiCTR-TRC- 12002762 . The date of registration is 31 October 2012.

Effect of Electroacupuncture on Inflammation in the Obese Zucker Fatty Rat Model of Metabolic Syndrome

Chronic inflammation is known to be associated with visceral obesity and insulin resistance and is characterized by altered levels of production of adipokines such as tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), IL-6, leptin, and adiponectin. Metabolic syndrome (MetS) is a major and escalating public health and clinical challenge worldwide, and patients with MetS have an increased risk of developing cardiovascular disease and type 2 diabetes mellitus. Electroacupuncture (EA) was tested as a means of decreasing inflammation in genetically obese Zucker fatty rats, which serve as a model of MetS. Repeated application of EA at the Zhongwan/Guanyuan acupoints decreased serum TNF-α, but produced no significant alterations in serum leptin, adiponectin, or IL-10. EA had no significant effect on the levels of these four adipokines in white adipose tissue. These findings are consistent with the supposition that EA inhibits proliferation and/or infiltration of macrophages into the adipose tissue of obese rats and stimulates the release of IL-10 from the decreased numbers of macrophages present in adipose tissue. Compared with the control animals, no significant change in body weight occurred. The blood glucose (BG) level over a 30-minute interval in Week 2 was relatively the same as that in Week 1, suggesting that EA treatment does not increase the likelihood of developing hyperglycemia.