Acupuncture mechanisms for clinical long-term effects, a hypothesis

Acupuncture for gouty arthritis: A PRISMA-compliant protocol for a systematic review and meta-analysis of randomized controlled trials

BACKGROUD

Patients with gouty arthritis suffer from intermittent attacks of pain, chronic inflammation, and joint damage. Acupuncture has been used in East Asian countries for centuries to treat various diseases, and several clinical studies have reported that acupuncture has beneficial effects on gouty arthritis. This study aims to evaluate the effect of acupuncture in patients with gouty arthritis by conducting a systematic review and meta-analysis.

METHODS

A comprehensive search of 8 electronic databases will be performed, including MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, 4 Korean databases (KoreaMed, Korean Studies Information Service System, Research Information Service System, and Oriental Medicine Advanced Searching Integrated System), and 1 Chinese database (China National Knowledge Infrastructure). Only randomized controlled trials comparing acupuncture to conventional treatment and acupuncture with conventional treatment to conventional treatment alone for gouty arthritis will be included. Pain intensity will be considered the primary outcome. The secondary outcomes will include the pain relief duration, total effective rate, blood uric acid level, inflammatory markers, and incidence of adverse events. Two independent researchers will perform the study selection, data extraction, and quality assessment. The methodological quality of the individual included studies will be assessed using the Cochrane risk of bias tool. In the meta-analysis, for dichotomous and continuous data, risk ratios and standardized mean differences, respectively, will be estimated in addition to 95% confidence intervals.

RESULTS

This systematic review will evaluate the effect of acupuncture treatment for patients with gouty arthritis with respect to clinical symptoms, laboratory indicators, and safety.

CONCLUSION

Our findings will help to establish the evidence of acupuncture to treat gouty arthritis.

REGISTRATION NUMBER

PROSPERO CRD42020169668.

Comparison of Acupuncture with Ibuprofen for Pain Management in Patients with Symptomatic Irreversible Pulpitis: A Randomized Double-Blind Clinical Trial

Emergency pain management in symptomatic irreversible pulpitis commonly includes use of nonnarcotic analgesics. Acupuncture has been used in dentistry to alleviate pain after tooth extraction. The aim of this randomized, double-blind, placebo controlled clinical trial was to evaluate and compare the efficacy of acupuncture therapy and ibuprofen for pain management in such patients. A total of 157 patients participated in this study and were randomly assigned to three groups, Group I-classical acupuncture with placebo tablet, Group II-sham acupuncture with placebo tablet, and Group III-sham acupuncture with ibuprofen. Before commencement of the experiment, initial pain assessment was done using a HP-VAS scale. Treatment was done by first operator, while pain assessment was done by the second operator who was blinded to the procedure performed. Acupuncture needles were inserted for 15-20 minutes at acupoints for classical acupuncture and at nonacupoints for sham acupuncture. Posttreatment pain assessment was carried out at 15, 30, 45, and 60 minutes intervals. Follow-up analysis was recorded at 12, 24, and 48 hours using VAS verbal scale. The mean final HP VAS values for Group I showed statistically significant lower pain values when compared with groups II and III (p < 0.05), with no significant difference between groups II and III. Follow-up analysis showed Group I with higher percentage of no pain, which was statistically significant when compared with other two groups. It can be concluded that classical acupuncture is more effective in pain relief (faster and prolonged) than analgesics.

Beep tones attenuate pain following Pavlovian conditioning of an endogenous pain control mechanism

Heterotopic noxious counter-stimulation (HNCS) is commonly used to study endogenous pain control systems. The resulting pain inhibition is primarily based on spinal cord-brainstem loops. Recently, functional imaging studies have shown that limbic structures like the anterior cingulate cortex and amygdala are also implicated. Since these structures are involved in learning processes, it is possible that the HNCS-induced pain inhibition may depend on specific cues from the environment that have been associated with pain reduction through associative learning. We investigated the influence of Pavlovian conditioning on HNCS-induced pain inhibition in 32 healthy subjects by using a differential conditioning paradigm in which two different acoustic stimuli were either repeatedly paired or unpaired with HNCS. Series of noxious electrical pulse trains delivered to the non-dominant foot served as test stimuli. Diffuse noxious inhibitory control (DNIC)-like effects were induced by concurrent application of tonic HNCS (immersion of the contralateral hand in ice water). Subjective pain intensity and pain unpleasantness ratings and electromyographic recordings of the facial corrugator muscle and the nocifensive RIII flexion reflex were used to measure changes in pain sensitivity. HNCS induced significant pain and reflex inhibitions. In the post-conditioning phase, only the paired auditory cue was able to significantly reduce pain perceptions and corrugator muscle activity. No conditioned effect could be observed in RIII reflex responses. Our results indicate that the functional state of endogenous pain control systems may depend on associative learning processes that, like in the present study, may lead to an attenuation of pain perception. Similar albeit opposite conditioning of pain control mechanisms may significantly be involved in the exacerbation and chronification of pain states.

The meridian system and mechanism of acupuncture-a comparative review. Part 1: the meridian system

In traditional Chinese medicine (TCM), acupuncture has been used to heal various diseases and physiologic malfunctions in clinical practice for more than 2500 years. Due to its efficacy, acupuncture has been recommended by the World Health Organization in 1980 as an effective alternative therapy for 43 different disorders. Over the past few decades, various theories of the meridian system and mechanisms have been proposed to explain how acupuncture might work. Most of these mechanisms, however, cannot yet explain conclusively why acupuncture is efficacious in treating so many different diseases. A plausible mechanism has been unavailable until recently. This is the first of a three-part series that aims to provide a comparative review of the aforementioned topics. Part 1 reviews the current indications for acupuncture, basic concepts of TCM, and the essence of the meridian system. To establish a mathematically rigorous framework of TCM, the chaotic wave theory of fractal continuum is proposed. This theory is then applied to characterize the essence of the meridian system. Parts 2 and 3 will review the possible mechanisms of acupuncture analgesia and acupuncture therapies, respectively, based on biochemical, bioelectromagnetic, chaotic wave, and neurophysiologic approaches. It is sincerely hoped that this series of review articles can promote an understanding of the meridian system and acupuncture mechanisms to help patients in a logical and passionate way.

Effect of Acupuncture on Rats with Acute Gouty Arthritis Inflammation: A Metabonomic Method for Profiling of Both Urine and Plasma Metabolic Perturbation

Acute gouty arthritis is a common inflammation model with multiple pathogenic mechanisms seen in clinical practice, for which acupuncture may potentially be an alternative therapy. To investigate the effect of acupuncture on acute gouty arthritis and search for its mechanism, a metabonomic method was developed in this investigation. Acute gouty arthritis model rats were induced by monosodium urate (MSU) crystals. The urine and plasma samples were collected at several time points and the endogenous metabolites were analyzed by an ultra-performance liquid chromatography coupled with a mass spectrometry (UPLC-MS). Data were analyzed using principal components analysis (PCA) and partial least squares (PLS) analysis to compare metabolic profiles of MSU crystal-induced acute gouty arthritis rats with MSU crystal-induced acute gouty arthritis, treated with acupuncture rats. The results showed that acupuncture could restore the metabolite network that disturbed by MSU administration. Our study indicates that UPLC-MS-based metabonomics can be used as a potential tool for the investigation of biological effect of acupuncture on acute gouty arthritis.

Neural mechanism underlying acupuncture analgesia

Acupuncture has been accepted to effectively treat chronic pain by inserting needles into the specific "acupuncture points" (acupoints) on the patient's body. During the last decades, our understanding of how the brain processes acupuncture analgesia has undergone considerable development. Acupuncture analgesia is manifested only when the intricate feeling (soreness, numbness, heaviness and distension) of acupuncture in patients occurs following acupuncture manipulation. Manual acupuncture (MA) is the insertion of an acupuncture needle into acupoint followed by the twisting of the needle up and down by hand. In MA, all types of afferent fibers (Abeta, Adelta and C) are activated. In electrical acupuncture (EA), a stimulating current via the inserted needle is delivered to acupoints. Electrical current intense enough to excite Abeta- and part of Adelta-fibers can induce an analgesic effect. Acupuncture signals ascend mainly through the spinal ventrolateral funiculus to the brain. Many brain nuclei composing a complicated network are involved in processing acupuncture analgesia, including the nucleus raphe magnus (NRM), periaqueductal grey (PAG), locus coeruleus, arcuate nucleus (Arc), preoptic area, nucleus submedius, habenular nucleus, accumbens nucleus, caudate nucleus, septal area, amygdale, etc. Acupuncture analgesia is essentially a manifestation of integrative processes at different levels in the CNS between afferent impulses from pain regions and impulses from acupoints. In the last decade, profound studies on neural mechanisms underlying acupuncture analgesia predominately focus on cellular and molecular substrate and functional brain imaging and have developed rapidly. Diverse signal molecules contribute to mediating acupuncture analgesia, such as opioid peptides (mu-, delta- and kappa-receptors), glutamate (NMDA and AMPA/KA receptors), 5-hydroxytryptamine, and cholecystokinin octapeptide. Among these, the opioid peptides and their receptors in Arc-PAG-NRM-spinal dorsal horn pathway play a pivotal role in mediating acupuncture analgesia. The release of opioid peptides evoked by electroacupuncture is frequency-dependent. EA at 2 and 100Hz produces release of enkephalin and dynorphin in the spinal cord, respectively. CCK-8 antagonizes acupuncture analgesia. The individual differences of acupuncture analgesia are associated with inherited genetic factors and the density of CCK receptors. The brain regions associated with acupuncture analgesia identified in animal experiments were confirmed and further explored in the human brain by means of functional imaging. EA analgesia is likely associated with its counter-regulation to spinal glial activation. PTX-sesntive Gi/o protein- and MAP kinase-mediated signal pathways as well as the downstream events NF-kappaB, c-fos and c-jun play important roles in EA analgesia.

Stage-dependent analgesia of electro-acupuncture in a mouse model of cutaneous cancer pain

Acupuncture is one of the most effective alternative medical treatments in pain management with the advantages of simple application, low cost and minimal side effects. However its scientific evidence and laws of action are not very clear in cancer pain relieving. The aim of this study was to examine the immediate and therapeutic anti-hyperalgesic effect of electro-acupuncture (EA) on a mouse model of cutaneous cancer pain. B16-BL6 melanoma cells were inoculated into the plantar region of unilateral hind paw and the thermal hyperalgesia was measured by using radiant heat test and hot plate test. C57BL/6 mice showed moderate and marked hyperalgesia during days 8-12 and from day 14 after the orthotopic inoculation of B16-BL6 melanoma cells into the hind paw. Single EA on day 8 after inoculation showed significant analgesic effect immediately after the treatment, the analgesic effect reached its maximum within 15-30min and declined to its minimum at 50min after EA treatment. Single EA treatment on day 20 showed no significant analgesic effect; Repeated EA treatments (started from day 8, once every other day) showed therapeutic analgesic effect, while it showed no therapeutic effect when started from day 16, a relatively late stage of this cancer pain model. The results demonstrated that EA had anti-hyperalgesic effect on early stage of cutaneous cancer pain but not on late stage. These results indicated a tight correlation of EA anti-hyperalgesic effects with the time window of cancer pain.