Mechanism of Acupuncture in Treating Obesity: Advances and Prospects.

Obesity is a common metabolic syndrome that causes a significant burden on individuals and society. Conventional therapies include lifestyle interventions, bariatric surgery, and pharmacological therapies, which are not effective and have a high risk of adverse events. Acupuncture is an effective alternative for obesity, it modulates the hypothalamus, sympathetic activity and parasympathetic activity, obesity-related hormones (leptin, ghrelin, insulin, and CCK), the brain-gut axis, inflammatory status, adipose tissue browning, muscle blood flow, hypoxia, and reactive oxygen species (ROS) to influence metabolism, eating behavior, motivation, cognition, and the reward system. However, hypothalamic regulation by acupuncture should be further demonstrated in human studies using novel techniques, such as functional MRI (fMRI), positron emission tomography (PET), electroencephalogram (EEG), and magnetoencephalography (MEG). Moreover, a longer follow-up phase of clinical trials is required to detect the long-term effects of acupuncture. Also, future studies should investigate the optimal acupuncture therapeutic option for obesity. This review aims to consolidate the recent improvements in the mechanism of acupuncture for obesity as well as discuss the future research prospects and potential of acupuncture for obesity.

Antihypertensive and Antifibrosis Effects of Acupuncture at PC6 Acupoints in Spontaneously Hypertensive Rats and the Underlying Mechanisms.

Long-term hypertension can lead to both structural and functional impairments of the myocardium. Reversing left ventricular (LV) myocardial fibrosis has been considered as a key goal for curing chronic hypertension and has been a hot field of research in recent years. The aim of the present work is to investigate the effect of electroacupuncture (EA) at PC6 on hypertension-induced myocardial fibrosis in spontaneously hypertensive rats (SHRs). Thirty SHRs were randomized into model, SHR + EA, and SHR + Sham EA groups with WKY rats as a normal control. EA was applied once a day for 8 consecutive weeks. The cardiac fibrosis as well as the underlying mechanisms were investigated. After 8 weeks of EA treatment at PC6, the enhanced myocardial fibrosis in SHRs was characterized by an increased ratio of left ventricular mass index (LVMI), collagen volume fraction (CVF), and elevated content of hydroxyproline (Hyp) as well as the upregulated expression of collagen I and collagen III in myocardium tissue of SHRs. All these abnormal alterations in the SHR + EA group were significantly lower compared to the model group. In addition, EA at PC6 significantly improved the pathological changes of myocardial morphology. Meanwhile, the increased levels of angiotensin II (Ang II) and tumor necrosis factor-α (TNFα) and expression of transforming growth factor ß1 (TGF-ß1), connective tissue growth factor (CTGF), matrix metalloproteinase (MMP)-2, and MMP-9 in the serum or heart tissue of SHRs were also markedly diminished by EA. These results suggest that EA at bilateral PC6 could ameliorate cardiac fibrosis in SHRs, which might be mediated by the regulation of the Ang II - TGF-ß1 pathway.

[Application of shear wave elastography in acupuncture research].

In recent years, a new technique of elastic quantization imaging, the ultrasound-based shear wave elastography (SWE) is arising, which has advantages of real-time, non-invasion, rapid imaging and strong repeatability, and quantifying the elastic properties of soft tissues including thyroid gland, breast, prostate, muscle tendon, ligament, etc.. It has been gradually applied to clinical and experimental researches of acupuncture and has an extensive application prospect. The present paper briefly introduces the application of SWE in accurately locating the acupoint, Deqi from needled acupoints, acupuncture manipulations, and evaluation of efficacy of acupuncture in the treatment of musculofascial diseases.

The Role of Adenosine A2b Receptor in Mediating the Cardioprotection of Electroacupuncture Pretreatment via Influencing Ca2+ Key Regulators.

OBJECTIVE: To investigate the roles played by A2b receptor and the key Ca2+ signaling components in the mediation of the cardioprotection of electroacupuncture pretreatment in the rats subjected to myocardial ischemia and reperfusion. METHODS: SD rats were randomly divided into a normal control (NC) group, ischemia/reperfusion model (M) group, electroacupuncture pretreatment (EA) group, and electroacupuncture pretreatment plus A2b antagonist (EAG) group. The ischemia/reperfusion model was made by ligation and loosening of the left descending branch of the coronary artery in all groups except the NC group. The EA group was pretreated with electroacupuncture at the Neiguan (PC6) point once a day for three consecutive days before the modeling. The elevation of the ST segment, arrhythmia scores, and myocardial infarction size of each group was measured. The relative expression levels of A2b, RyR2, SERCA2a, NCX1, P-PLB(S16)/PLB, and Troponin C/Troponin I proteins in the injured myocardium were detected by multiple fluorescence western blot. RESULTS: The level of ST segment, arrhythmia scores, and infarct size in the M group was significantly higher/larger than that in the NC group after ischemia and reperfusion, while all the three indices mentioned above in the EA group were significantly lower/smaller than those in the M group after reperfusion. The expression of the proteins of adenosine receptor 2b(A2b), ryanodine receptor 2(RyR2), and sarco(endo)plasmic reticulum Ca2+-ATPase 2a (SERCA2a) in the EA group was significantly enhanced as compared with the M group, while in the EAG group, the contents of A2b were significantly lower than those in the EA group, and RyR2 was higher in the EAG group. In comparison with the NC group, the relative expression of NCX1 protein in M, EA, and EAG groups was not changed significantly. The ratio of phosphorylated phospholamban (P-PLB) over phospholamban (PLB) in the M group was significantly lower than that in the NC group, and the ratio in the EA group was significantly increased as compared with the M group, while the ratio of Troponin C/Troponin I in the EA group was significantly decreased in comparison with that in other groups. CONCLUSION: Electroacupuncture pretreatment could reduce ischemia and reperfusion-induced myocardial injury via possibly increasing the A2b content and regulating the key Ca2+ signaling components, namely inhibiting RyR2 and enhancing P-PLB(S16)/PLB ratio and SERCA2a proteins, so as to diminish the intracellular Ca2+ overload and consequently lessen the myocardial injury.

[Impact of different anesthetic states on acupuncture-mediated modulation of autonomic nervous system in animal studies].

Acupuncture therapy has a positive role in the prevention and treatment of some related diseases by regulating autonomic nervous function. But it has been found in experimental researches that the modulatory effects of acupuncture on autonomic nervous system are not always consistent with each other. Because in the animal studies on the mechanism of acupuncture intervention, the anesthetic agent has to be used and definitely affects the activities of the autonomic nervous system while playing its pharmacological effects. Hence, it is very significant to explore the rational application of anesthetic agents and minimize their unfavorable impacts on the research outcomes. In the present paper, we make a retrospective analysis on (1) the effect of acupuncture intervention on activities of the autonomic nerve in animal models of myocardial ischemia, gastrointestinal mobility, and urinary system; (2) the effect of anesthetics as isoflurane, urethane, pentobarbital sodium, ketamine, α-chloralose, propofolum, etc. on activities of the autonomic nerve system. In terms of different anesthetic modes and various depths of anesthesia by using isoflurane inhalation, mixed solution of urethane and chloralose, etc., some approaches for assessing the state of anesthesia in accordance with the pupillary reflex, righting reflex, footboard reflex, swallowing reflex, heart rate, blood pressure, body temperature, respiration frequency, ventilation volume, oxygen saturation, partial pressure of carbon dioxide, neuromuscular blo-ckade, etc. in combination with the indexes directly and indirectly reflecting functions of the sympathetic and vagus nerves are proposed to analyze the impact of different anesthetic states on the therapeutic effect of acupuncture in various models of dysfunction of the autonomic nerve system. Under the circumstances, it is possible to provide a reference for rational use of anesthetic agents and dosages in the acupuncture research of autonomic nerve regulation.

[Application of heart rate variability in acupuncture research].

The measurement of heart rate variability (HRV) has the advantages of noninvasiveness and simple operation and is widely used in clinical trials and scientific research for assessing reactions of the autonomic nervous system. More and more studies on acupuncture also take HRV as an important index. In addition to the definition, origin, analytical methods, and significance of time domain and frequency domain parameters of HRV, we reviewed the situations of application of HRV to acupuncture research in recent years, analyzed the influence of acupuncture and sham acupuncture, different acupuncture methods, and different acupoints on HRV, and confirmed the role of HRV in reflecting the effect of acupuncture on the vagal and sympathetic systems. However, various interference factors for HRV measurement and diverse methods for data analysis may lead to great differences in the experimental results of HRV and the interpretation of parameters. Therefore, careful analysis is needed in future studies on acupuncture with HRV as an observation index.

[A Potential Role of Adenosine A 2 b Receptor in Mediating Acupuncture Pretreatment Induced Cardioprotection via Influencing Intracellular Calcium Regulator].

It has been shown that ischemia preconditioning (IPC) can attenuate the myocardial injury induced by ischemic and reperfusion. But it was rarely used in clinic due to its inoperability. Previous studies indicate that electroacupuncture (EA) pretreatment can mimic myocardial ischemia preconditioning (MIPC) to produce cardioprotective effect. The activated adenosine A 2 b receptor has been proven to be involved in mediating the cardioprotection of IPC. In the studies on acupuncture analgesia, it was reported that adenosine receptor was activated by acupuncture stimulation, and acupuncture pretreatment can affect the acti-vities of intracellular A 2 b receptor. Based on those mentioned above, it is highly likely that the A 2 b receptor may also participate in the cardioprotection produced by acupuncture pretreatment. In this paper, we comprehensively reviewed relevant studies regarding 1) the cardioprotective effect of IPC and its limitations, 2) the similar cardioprotection produced by both acupuncture pre-treatment and IPC, 3) the mechanism underlying myocardial ischemic injury and intracellular calcium regulation, 4) the acti-vation of adenosine receptors and effects of acupuncture, 5) the relationship between adenosine receptors and intracellular calcium ion, and 6) the effect of acupuncture on adenosine receptors, so as to provide a novel assumption that A 2 b receptor may be a key factor in mediating the cardioprotection of acupuncture pretreatment. Our future research will systematically explore the me-chanism of acupuncture pretreatment in protecting ischemic myocardium from myocardial cell adenosine A 2 b receptor and intracellular calcium signal transduction related factors.

Effect of acupuncture on the TLR2/4-NF-κB signalling pathway in a rat model of traumatic brain injury.

OBJECTIVE: To study the effect of acupuncture on the TLR2/4-NF-κB signalling pathway in the cortex of Sprague-Dawley rats following traumatic brain injury (TBI), and investigate the possible mechanism underlying the effects of acupuncture on scar repair. METHODS: TBI was established using Feeney's free-falling epidural percussion model. In total, 108 rats were randomly divided into a normal group (n=18), untreated TBI model group (TBI group, n=36) and manual acupuncture-treated TBI group (TBI+MA, n=36). Each group of rats was subdivided into three time groups: 3-day (3d), 7-day (7d) and 14-day (14d). No treatment was given to rats in the normal and TBI groups. The TBI+MA group received manual acupuncture at GV20, GV26, GV16 through GV15, and bilateral LI4. mRNA expression of TLR2, TLR4, NF-κB and protein in the rat cortices was quantified using real-time fluorescence quantitative polymerase chain reaction (qPCR) and Western blot analyses. RESULTS: The modified neurological severity score (mNSS) scores of the TBI+MA group were improved compared with baseline scores 12 hours after modelling, and improved at 7d and 14d compared with the TBI group (P<0.05), while the score of the TBI group did not improve until 14d compared to baseline. mRNA and protein expression of TLR2, TLR4 and NF-κB in the TBI group were higher than the normal group at 3d (P<0.05), reached a peak at 7d, then began to decrease at 14d. mRNA and protein expression of TLR2, TLR4 and NF-κB were higher in the TBI+MA group compared with the TBI group at 3d (P<0.05), were significantly down-regulated at 7d (P<0.01), and decreased to normal levels at 14d. CONCLUSIONS: Acupuncture has a bidirectional regulatory effect on the TLR2/4-NF-κB signalling pathway-related genes TLR2, TLR4 and NF-κB in the TBI rat cortex, promoting their expression in the early stage and inhibiting it in the later stage.

Effect of Acupuncture on the Notch Signaling Pathway in Rats with Brain Injury.

OBJECTIVE: To observe the effect of acupuncture on the Notch signaling pathway in rats with traumatic brain injury and to explore the pathogenesis of acupuncture intervention on traumatic brain injury. METHODS: Feeney's freefall epidural impact method was used to establish a traumatic brain injury model in rats; the rats were randomly divided into a normal group, sham operation group, model group and acupuncture group. Acupuncture was performed in the Baihui (DU 20), Shuigou (DU 26), Fengfu (DU 16), Yamen (DU 15) and Hegu (LI 4) acupoints in the rat, and Yamen was punctured via Fengfu. Then, the rats in each group were randomly divided into three subgroups, namely the day 3 subgroup, day 7 subgroup and day 14 subgroup according to treatment duration. The modified neurological severity scores (mNss) method was used to perform neurobehavioral scoring for evaluating the degree of injury in the rats. The hematoxylin-eosin (HE) staining method was used to observe the pathological change in the brain tissue of rats in each group. Real-time fluorescent quantitative polymerase chain reaction (Q-PCR) technology was used to detect changes in the Notch1, Hes1 and Hes5 gene expression levels in the cortex on the injured side. Western blot was used to detect the protein expression changes. RESULTS: One day after modeling, the mNss scores in the model group and in the acupuncture group were significantly higher than those in the normal and sham operation groups (P<0.01) ; there was no statistically significant difference between the normal group and the sham operation group. The scores decreased with increased treatment time, and the scores in the acupuncture group decreased more significantly than those in the model group (P<0.01). The pathological examination by the HE staining method demonstrated that the brain tissue of the rats in the acupuncture and model groups relatively significantly changed. The Notch1 gene expression level in the acupuncture group was significantly higher than the level in all of the other groups (P<0.01) ; the Hes1 and Hes5 gene expression levels were also higher in the acupuncture group. The expression changes of the Notch1 and Hes1 protein were consistent with that of mRNA. In each experimental group, the mNss score and the pathological results by the HE staining method were consistent with the mRNA results. CONCLUSION: Acupuncture could significantly promote high expression levels of Notch1, Hes1 and Hes5 in the brain tissue of traumatic brain injury rats. Therefore, acupuncture might be an important intervention for inducing endogenous stem cell proliferation and for promoting nerve repair.

Effects of acupuncture on cortical expression of Wnt3a, ß-catenin and Sox2 in a rat model of traumatic brain injury.

OBJECTIVE: To observe the effects of acupuncture treatment on the expression of Wnt/ß-catenin signalling pathway-related genes (Wnt3a, ß-catenin and Sox2) in the injured cerebral cortex of rats with traumatic brain injury (TBI). METHODS: A controlled impact model of TBI was established using Feeney's free-drop method. Seventy-eight Sprague-Dawley rats were randomly divided into the following three groups: a normal group (n=18) that was left untreated; a model group (n=30) that received no treatment after TBI; and an acupuncture group (n=30) that received acupuncture (at LI4, GV20, GV26 and GV16) after TBI. Rats in each group were randomly and equally divided into 3-day, 7-day and 14-day subgroups according to the duration of therapy. Real-time fluorescence quantitative PCR (RT-qPCR) was used to measure mRNA expression of Wnt3a, ß-catenin and Sox2. Western blots were performed to determine the expression levels of WNT3a, ß-Catenin and SOX2. RESULTS: Wnt3a mRNA was upregulated in the 7-day and 14-day acupuncture subgroups compared with the corresponding model subgroups (p<0.05). ß-catenin expression was significantly increased in the 7-day and 14-day acupuncture subgroups compared with the corresponding model subgroups (p<0.01). In the 3-day and 7-day acupuncture subgroups, Sox2 expression was significantly higher than that in the normal and model groups (p<0.01 each). The levels of WNT3a, ß-catenin and SOX2 were generally consistent with the corresponding mRNA levels. CONCLUSIONS: Acupuncture exerts a regulatory effect on the Wnt/ß-catenin signalling pathway, which may in turn influence the proliferation and differentiation of endogenous neural stem cells.