Microcurrent Stimulation Research Articles

Effect of Low-Level Laser Acupuncture and Microcurrent Electrical Stimulation on Gag Reflex in Children During Dental Impression: A Randomized Controlled Clinical Trial.

Dental impressions are crucial in pediatric dentistry, but exaggerated gagging can obstruct this process. Various methods have been proposed to manage the gag reflex (GR). This study aimed to evaluate and compare the effectiveness of laser acupuncture and electroacupuncture in controlling children's GR. A three-armed randomized controlled trial was conducted with 63 patients aged 6-9, with excessive GR, scheduled for dental impressions. Participants were assigned to one of three groups: low-level laser (n = 21), microcurrent stimulation with a Meridian pen (n = 21), and a control group with a deactivated pen (n = 21). Gag preventive index (GPI) was taken, and dental anxiety was assessed using the Facial Image Scale (FIS), pulse rate (PR), and blood oxygen saturation (SaO2). Significance was set at p < 0.05. All interventions influenced GPI scores. The Meridian pen and laser groups achieved better GPI scores (p < 0.001) than the control group. FIS scores between the Meridian pen and laser groups were comparable, differing significantly from the control group (p < 0.001). The Meridian pen and laser groups showed greater reductions in PR (p < 0.001) and higher SaO2 post-intervention (p < 0.001). The Meridian pen and laser outperformed the control group, demonstrating effectiveness in enhancing physiological and subjective measures. ClinicalTrials.gov identifier: NCT06422286.

Enhanced electron transfer for the improvement of nitrogen removal efficiency and N2O reduction at low temperatures.

Low temperature generally restricts biological activity, slowing down electron transfer in biogeochemical cycles and causing a series of environmental problems such as nitrogen pollution. We present a strategy to boost electron transfer in microbial cell at low temperatures via stimulation with low current. It is demonstrated by establishing a constructed wetland system coupled with solar powered microbial electrolysis cell, which enhances microbial activity through external micro currents (18.9 ± 5.5 μA) for removing nitrogen pollution in winter (average temperature from -6.6 to 4.5 °C). We investigated the efficiency of pollutants removal, microbial activity, N2O production and its mechanisms using complexes activity detection, RT-qPCR, incubation, and 15N-18O dual-isotope labeling techniques. The activity of complexes I, II, III, and IV collectively represent the microbial electron transfer rate. Results indicated that the microcurrents increased the activity of complexes II, III and IV by 96 %, 172 %, and 313 %, respectively. The transcription abundance of amoA genes in ammonia oxidation and nirS/K genes in denitrification by 263 % and 51 %, respectively. Consequently, NH4+-N removal efficiency improved from 23 % to 35 %, and NO3--N removal efficiency from 21 % to 31 %. Moreover, microcurrents reduced N2O emission by 44 %. However, external microcurrent stimulation did not alter the microbial production pathway of N2O as determined by the 15N-18O dual isotope labeling technique. The relative abundance of the nitrifying bacteria Nitrosomonas, Nitrosospira, and Nitrospira, as well as the denitrifying bacteria Methylotenera, significantly increased due to microcurrent stimulation. Specifically, Nitrospira exhibited the highest increase of 156 %. Our findings provide a novel way to enhance N removal efficiency and simultaneously reduce N2O emission of biological system like constructed wetlands in winter conditions.

The Neuroprotective Effects of Peripheral Nerve Microcurrent Stimulation Therapy in a Rat Model of Middle Cerebral Artery Occlusion.

This study investigated the neuroprotective effects of peripheral nerve microcurrent stimulation therapy in a rat model of middle cerebral artery occlusion (MCAO). Twenty 8-week-old male Sprague Dawley rats weighing 300-330 g were categorised into group A, serving as the healthy control; group B, including rats subjected to MCAO; group C, including rats receiving microcurrent therapy immediately after MCAO, which was continued for one week; and group D, including rats receiving microcurrent therapy one week before and one week after MCAO. A gross morphological analysis, behavioural motion analysis, histological examination, immunohistochemistry, and Western blotting were conducted. Microcurrent therapy significantly reduced ischaemic damage and pyramidal cells of the hippocampus CA1 region. Haematoxylin and eosin staining revealed infarction areas/viable pyramidal cell numbers of 0%/94.33, 28.53%/40.05, 17.32%/80.13, and 5.38%/91.34 in groups A, B, C, and D, respectively (p < 0.001). A behavioural analysis revealed that the total distances moved were 1945.24 cm, 767.85 cm, 1781.77 cm, and 2122.22 cm in groups A, B, C, and D, respectively (p < 0.05), and the mean speeds were 6.48 cm/s, 2.50 cm/s, 5.43 cm/s, and 6.82 cm/s, respectively (p < 0.05). Inflammatory markers (cluster of differentiation 68, interleukin-6, and tumour necrosis factor-α) significantly decreased in the treated groups (p < 0.001). Western blotting revealed reduced proinflammatory, oxidative stress, and apoptosis-related protein levels, along with increased angiogenic factors and mitogen-activated protein kinase (MAPK) pathway modulation in the treated groups. Peripheral nerve microcurrent stimulation therapy effectively mitigates ischaemic damage, promotes recovery, reduces inflammation, and modulates protein expression, emphasising its potential as a therapeutic strategy for ischaemic stroke.

Micro-current stimulation could inhibit IL-1β-induced inflammatory responses in chondrocytes and protect knee bone cartilage from osteoarthritis.

This study aimed to evaluate the inhibitory effects of micro-current stimulation (MCS) on inflammatory responses in chondrocytes and degradation of extracellular matrix (ECM) in osteoarthritis (OA). To determine the efficacy of MCS, IL-1β-treated chondrocytes and monosodium iodoacetate (MIA)-induced OA rat model were used. To evaluate the cytotoxicity and nitric oxide (NO) production in SW1353 cells, the presence or absence of IL-1β treatment or various levels of MCS were applied. Immunoblot analysis was conducted to evaluate whether MCS can modulate IL-1R1/MyD88/NF-κB signaling pathway and various indicators involved in ECM degradation. Additionally, to determine whether MCS alleviates subchondral bone structure destruction caused by OA, micro-CT analysis, immunoblot analysis, and ELISA were conducted using OA rat model. 25 and 50 µA levels of MCS showed effects in cell proliferation and NO production. The MCS group with IL-1β treatment lead to significant inhibition of protein expression levels regarding IL-1R1/MyD88/NF-κB signaling and reduction of the nucleus translocation of NF-κB. In addition, the protein expression levels of MMP-1, MMP-3, MMP-13, and IL-1β decreased, whereas collagen II and aggrecan increased. In animal results, morphological analysis of subchondral bone using micro-CT showed that MCS induced subchondral bone regeneration and improvement, as evidenced by increased thickness and bone mineral density of the subchondral bone. Furthermore, MCS-applied groups showed decreases in the protein expression of MMP-1 and MMP-3, while increases in collagen-II and aggrecan expressions. These findings suggest that MCS has the potential to be used as a non-pharmaceutical method to alleviate OA.

Bioelectric medicine: unveiling the therapeutic potential of micro-current stimulation.

Bioelectric medicine (BEM) refers to the use of electrical signals to modulate the electrical activity of cells and tissues in the body for therapeutic purposes. In this review, we particularly focused on the microcurrent stimulation (MCS), because, this can take place at the cellular level with sub-sensory application unlike other stimuli. These extremely low-level currents mimic the body's natural electrical activity and are believed to promote various physiological processes. To date, MCS has limited use in the field of BEM with applications in several therapeutic purposes. However, recent studies provide hopeful signs that MCS is more scalable and widely applicable than what has been used so far. Therefore, this review delves into the landscape of MCS, shedding light on the multifaceted applications and untapped potential of MCS in the realm of healthcare. Particularly, we summarized the hierarchical mediation from cell to whole body responses by MCS including its physiological applications. Our final objective of this review is to contribute to the growing body of literature that unveils the captivating potential of BEM, with MCS poised at the intersection of technological innovation and the intricacies of the human body.

A dual-crosslinking electroactive hydrogel based on gelatin methacrylate and dibenzaldehyde-terminated telechelic polyethylene glycol for 3D bio-printing

Gelatin was widely used as scaffold materials in 3D bio-printing due to its excellent bioactivity and availability and especially that their arginine–glycine–aspartic acid (RGD) sequences could efficiently promote cell adhesion and proliferation. In this study, an electroactive and 3D bio-printable hydrogel was prepared through a two-step chemical cross-linking process. Specifically, residual free amino groups of methacrylated gelatin (GelMA) were cross-linked with the aldehyde groups of dibenzaldehyde-terminated telechelic polyethylene glycol (DF-PEG) via Schiff base bonds, forming a gel at 37 °C. During the subsequent 3D bio-printing process, GelMA underwent UV curing, forming a secondary cross-linked network to the mechanical strength and stability of the printed structure. The uniform dispersion of carbon nanotubes (CNTs) in the GelMA/DF-PEG composite hydrogel significantly increased its conductivity. The optimized GelMA/DF-PEG composite hydrogel, i.e., 30% GelMA and 25% DF-PEG (G30D25-CNTs), exhibited superior bio-printability. When the content of CNTs was above 4%, the conductivity of G30D25-CNTs hydrogel exceeded 10–2 S/m, which satisfied the needs of cells for micro-current stimulation. Furthermore, the pore microstructures, swelling behavior, degradation ability and cell toxicity of G30D25-CNTs electroactive hydrogels were thoroughly evaluated. Thus, the G30D25-CNTs hydrogel with 4% MWCNTs could be considered for further application in electrical stimulation of tissue regeneration such as muscle and cardiac nerve tissue repair.

Enhancing regeneration and repair of long-distance peripheral nerve defect injuries with continuous microcurrent electrical nerve stimulation.

Peripheral nerve injuries, especially those involving long-distance deficits, pose significant challenges in clinical repair. This study explores the potential of continuous microcurrent electrical nerve stimulation (cMENS) as an adjunctive strategy to promote regeneration and repair in such cases. The study initially optimized cMENS parameters and assessed its impact on Schwann cell activity, neurotrophic factor secretion, and the nerve regeneration microenvironment. Subsequently, a rat sciatic nerve defect-bridge repair model was employed to evaluate the reparative effects of cMENS as an adjuvant treatment. Functional recovery was assessed through gait analysis, motor function tests, and nerve conduction assessments. Additionally, nerve regeneration and denervated muscle atrophy were observed through histological examination. The study identified a 10-day regimen of 100uA microcurrent stimulation as optimal. Evaluation focused on Schwann cell activity and the microenvironment, revealing the positive impact of cMENS on maintaining denervated Schwann cell proliferation and enhancing neurotrophic factor secretion. In the rat model of sciatic nerve defect-bridge repair, cMENS demonstrated superior effects compared to control groups, promoting motor function recovery, nerve conduction, and sensory and motor neuron regeneration. Histological examinations revealed enhanced maturation of regenerated nerve fibers and reduced denervated muscle atrophy. While cMENS shows promise as an adjuvant treatment for long-distance nerve defects, future research should explore extended stimulation durations and potential synergies with tissue engineering grafts to improve outcomes. This study contributes comprehensive evidence supporting the efficacy of cMENS in enhancing peripheral nerve regeneration.

The Effectiveness of Microcurrent Stimulation Combined with Sound Therapy for Tinnitus Relief: A Preliminary Study.

Various stimulation-based rehabilitation approaches have been proposed to alleviate tinnitus. This study aimed to determine the efficacy of a rehabilitation approach that simultaneously provides microcurrent and sound stimulation for tinnitus relief. Twenty-eight participants with chronic sensorineural tinnitus were randomly assigned to one of two groups based on the rehabilitation approaches (sound therapy-only group and combined microcurrent and sound therapy group). Each participant underwent sound therapy or simultaneous stimulation for approximately 2 h daily for 3 months. The effectiveness of the rehabilitation approaches was determined based on changes in the Korean version of the tinnitus primary function questionnaire (K-TPFQ) and visual analog scale for loudness (VAS-L) scores at baseline, 1.5 months, and 3 months. For the K-TPFQ scores, both groups exhibited a large effect of rehabilitation; however, for the VAS-L scores, the simultaneous stimulation group demonstrated a large effect of rehabilitation, whereas the sound therapy group exhibited a small effect. Therefore, a rehabilitation approach that combines sound stimulation with microcurrent stimulation can improve response and perception in tinnitus.

Transpalpebral electrical stimulation for the treatment of retinitis pigmentosa: study protocol for a series of N-of-1 single-blind, randomized controlled trial

BackgroundRetinitis pigmentosa (RP) is an inherited disease characterized by a progressive loss of rod photoreceptors of the eye, leading to irreversible blindness. To date, to our knowledge, no clinical prospective studies have been undertaken that could document the effect of interventions that could reverse or reduce the progression of this disease. The application of microcurrent stimulation (ES) of the eye in the treatment of chronic eye diseases such as glaucoma and age-related macular degeneration has been used over several decades and has been reported to have beneficial effects to reduce the progression of these blinding diseases and has been supported by animal studies and smaller clinical studies, but to date, no large randomized clinical trials on the use of microcurrent therapy have been published. More recent clinical reports have also shown beneficial effects of ES on slowing the progression of RP but also lacks data from robust prospective clinical outcome studies. To our knowledge, this is the first prospective randomized study to evaluate the safety and clinical effectiveness of transpalpebral electrical stimulation (TpES) on the progression of RP.MethodsRandomized prospective study using N-of-1 trial 3 single-blind, crossover comparisons. The intervention period of each comparison is divided into treatment period and control period which are randomized arranged. Twelve participants will be strictly recruited in N-of-1 trial by the researcher in accordance with the inclusion and exclusion criteria. The main outcome of interest examined after each cycle of the 8-week intervention period is the assessment of the visual field (VF). Other variables of interest are best corrected visual acuity (BCVA), retinal function using electroretinogram (ERG), and visual function using NEI VFQ-25 questionnaire. Objective assessments of retinal changes will be undertaken using optical coherence tomography (OCT) and fundus autofluorescence (FAF).DiscussionThe trial will evaluate the efficacy and safety of microcurrent stimulation on RP and provide high-quality evidence for clinical application through N-of-1 trial.Trial registrationChinese Clinical Trial Registry; ChiCTR2300067357; https://www.chictr.org.cn/showproj.html?proj=174635. Registered on 5 January 2023

The Effect of Microcurrent Stimulation on Pain and Quality of Life in Women with Primary Dysmenorrhea

The Effect of Microcurrent Stimulation on Pain and Quality of Life in Women with Primary Dysmenorrhea

Association between Patients' Body Mass Index and the Effect of Monophasic Pulsed Microcurrent Stimulation on Pressure Injury Healing.

This secondary analysis study aimed to detect individual variables that influence the efficacy of monophasic pulsed microcurrent on pressure injury healing. Eleven patients with pressure injuries showing delayed healing underwent a microcurrent stimulation period and a placebo period. We analyzed the correlation between the individual variables and the following three outcomes using monophasic pulsed microcurrent: the wound reduction rate in the electrical stimulation period, the reduction rate in the placebo period, and the difference between these two reduction rates. Furthermore, the patients were divided into two groups, one with a wound reduction rate of more than 10% and the other with less than 10%, and the relationship between each variable was compared. As a result, the wound reduction rate in the electrical stimulation period and the difference in the reduction rate between the two periods showed significant positive correlations with patients' body mass index. In addition, a significant difference was observed in the body mass index between subjects with a reduction rate of 10% or higher and those with a reduction rate of less than 10%. This study found a correlation between the effect of monophasic pulsed microcurrent for pressure injury healing and the level of patients' body mass index.

Micro-Current Stimulation Can Modulate the Adipogenesis Process by Regulating the Insulin Signaling Pathway in 3T3-L1 Cells and ob/ob Mice.

Obesity is a disease in which fat is abnormally or excessively accumulated in the body, and many studies have been conducted to overcome it with various techniques. In this study, we evaluated whether micro-current stimulation (MCS) can be applied to prevent obesity by regulating the adipogenesis through 3T3-L1 cells and ob/ob mice. To specify the intensity of MCS, Oil Red O staining was conducted with various intensities of MCS. Based on these, subsequent experiments used 200 and 400 μA for the intensity of MCS. The expressions of insulin signaling pathway-related proteins, including phosphorylation of IGF-1 and IR, were decreased in all MCS groups, and in turn, downstream signals such as Akt and ERK were decreased. In addition, MCS reduced the nucleus translocation of PPAR-γ and decreased the protein expression of C/EBP-α. In the ob/ob mouse model, MCS reduced body weight gain and abdominal adipose tissue volume. In particular, the concentration of triglycerides in serum was also decreased. Taken together, our findings showed that MCS inhibited lipid accumulation by regulating insulin signaling in 3T3-L1, and it was effective at reducing body weight and adipose tissue volume in ob/ob mice. These suggest that MCS may be a useful treatment approach for obesity.

Electrically stimulated 3D bioprinting of gelatin-polypyrrole hydrogel with dynamic semi-IPN network induces osteogenesis via collective signaling and immunopolarization

In recent years, three-dimensional (3D) bioprinting of conductive hydrogels has made significant progress in the fabrication of high-resolution biomimetic structures with gradual complexity. However, the lack of an effective cross-linking strategy, ideal shear-thinning, appropriate yield strength, and higher print fidelity with excellent biofunctionality remains a challenge for developing cell-laden constructs, hindering the progress of extrusion-based 3D printing of conductive polymers. In this study, a highly stable and conductive bioink was developed based on polypyrrole-grafted gelatin methacryloyl (GelMA-PPy) with a triple cross-linking (thermo-photo-ionically) strategy for direct ink writing-based 3D printing applications. The triple-cross-linked hydrogel with dynamic semi-inner penetrating polymer network (semi-IPN) displayed excellent shear-thinning properties, with improved shape fidelity and structural stability during 3D printing. The as-fabricated hydrogel ink also exhibited “plug-like non-Newtonian” flow behavior with minimal disturbance. The bioprinted GelMA-PPy-Fe hydrogel showed higher cytocompatibility (93%) of human bone mesenchymal stem cells (hBMSCs) under microcurrent stimulation (250 mV/20 min/day). Moreover, the self-supporting and tunable mechanical properties of the GelMA-PPy bioink allowed 3D printing of high-resolution biological architectures. As a proof of concept, we printed a full-thickness rat bone model to demonstrate the structural stability. Transcriptomic analysis revealed that the 3D bioprinted hBMSCs highly expressed gene hallmarks for NOTCH/mitogen-activated protein kinase (MAPK)/SMAD signaling while down-regulating the Wnt/β-Catenin and epigenetic signaling pathways during osteogenic differentiation for up to 7 days. These results suggest that the developed GelMA-PPy bioink is highly stable and non-toxic to hBMSCs and can serve as a promising platform for bone tissue engineering applications.

Enhanced bone regeneration via ZIF-8 decorated hierarchical polyvinylidene fluoride piezoelectric foam nanogenerator: Coupling of bioelectricity, angiogenesis, and osteogenesis

Piezoelectric biomaterials are advantageous in terms of easy generation of transduced bioelectrical signals to skeleton systems in response to body movements or external stimulations. In the bone formation process, the coupling of angiogenesis-osteogenesis is crucial but the effect of piezoelectric biomaterials on angiogenesis and mechanism of stress-transformed electrical signals affecting vascular cells remain elusive. In this work, hierarchically architected polyvinylidene fluoride (PVDF) foam fabricated by solid-state shearing milling was further decorated with ZIF-8 nanocrystals. The unique hierarchical porous structure realizes stable voltage outputs up to 10 V without polarization. The electric potential of piezoelectric PVDF affected molecular trajectory of Zn2+ released from ZIF-8, leading to Zn2+ enrichment around the PVDF surface. Under piezoelectric condition, PVDF/ZIF-8 foams promoted in-vitro angiogenic and osteogenic activity as well as antibacterial effect. Upon calvarium and femur defect repair, PVDF/ZIF-8 piezoelectric foams also guided vascularized bone regeneration through micro-current stimulation and Zn2+ enrichment. RNA-seq demonstrated PVDF/ZIF-8 piezoelectric foam mainly up-regulated ATP coupled cation transmembrane transportation in vascular endothelial cells, which enhanced cellular uptake of Zn2+, indicating the synergistic effect of piezoelectric PVDF and bioactive ZIF-8. This work offers a preliminary explanation for mechanism of angiogenesis-osteogenesis coupling of PVDF/ZIF-8 foam nanogenerator and provides a valuable complement to clinical treatment strategies for bone defect repair.

In vitro evaluation of electrospun polyvinylidene fluoride hybrid nanoparticles as direct piezoelectric membranes for guided bone regeneration

A polyvinylidene fluoride (PVDF) piezoelectric membrane containing carbon nanotubes (CNTs) and graphene oxide (GO) additives was prepared, with special emphasis on the piezoelectric activity of the aligned fibers. Fibroblast viability on membranes was measured to study cytotoxicity. Osteoprogenitor D1 cells were cultured, and mineralization of piezoelectric composite membranes was assessed by ultrasound stimulation. Results showed that the electrospun microstructures were anisotropically aligned fibers. As the GO content increased to 1.0 wt% (0.2 wt% interval), the β phase in PVDF slightly increased but showed the opposite trend with the increase in CNT. Excessive addition of GO and CNT hindered the growth of the β phase in PVDF. The direct piezoelectric activity and mechanical properties showed the same trend as the β phase in PVDF. Moreover, GO/PVDF with the same nanoparticle content showed better performance than CNT/PVDF composites. In this study, a comparison of the generated piezoelectric specific voltage (unit: 10−3 Vg−1 cm−2, linear stretch, g33) with control PVDF only (0.55 ± 0.16) revealed that the two composites containing 0.8 wt% GO- and 0.2 wt% CNT- with 15 wt% PVDF exhibited excellent piezoelectric voltages, which were 3.37 ± 1.05 and 1.45 ± 0.07 (10−3 Vg−1 cm−2), respectively. In vitro cultures of these two groups in contact with D1 cells showed significantly higher alkaline phosphatase secretion than the PVDF only group within 1–10 days of cell culture. Further application of ultrasound stimulation showed that the piezoelectric membrane differentiated D1 cells earlier than without ultrasound and induced higher proliferation and mineralization. This developing piezoelectric effect is expected to generate voltage through activities to enhance microcurrent stimulation in vivo.

Effectiveness of Microcurrent Therapy for Treating Pressure Ulcers in Older People: A Double-Blind, Controlled, Randomized Clinical Trial.

The aim of this study was to assess the effectiveness of microcurrent therapy for healing pressure ulcers in aged people. A multicentric, randomized clinical trial was designed with a sham stimulation control. The experimental group received an intervention following a standardized protocol for curing ulcers combined with 10 h of microcurrent therapy daily for 25 days. The sham group received the same curing protocol plus a sham microcurrent stimulation. The studied healing-related variables were the Pressure Ulcer Scale for Healing (PUSH) and the surface, depth, grade, and number of ulcers that healed completely. Three evaluations were conducted: pre-intervention (T1), 14 days following the start of the intervention (T2), and 1 day after the intervention was completed (T3). In total, 30 participants met the inclusion criteria (n = 15 in each group). The improvement in the PUSH at T2 and T3 was 16.8% (CI95% 0.5–33.1) and 25.3% (CI95% 7.6–43.0) greater in the experimental group versus the sham control, respectively. The reduction in the wound area at T2 and T3 was 20.1% (CI95% 5.2–35.0) and 28.6% (CI95% 11.9–45.3) greater in the experimental group versus the control, respectively. Microcurrent therapy improves the healing of pressure ulcers in older adults, both quantitatively and qualitatively.

Study on the Treatment of LDH Rats by Microcurrent Stimulation through MAPK, Wnt/��-catenin and NF-��B Signal Pathway

Study on the Treatment of LDH Rats by Microcurrent Stimulation through MAPK, Wnt/��-catenin and NF-��B Signal Pathway

Microcurrent Frequencies’ Effect on the Cell Membrane Potential

Research shows that cellular and mitochondrial (ΔΨm) membrane potentials are strong indicators of cellular physiology. In this paper we review further research suggesting that microcurrent frequencies can positively influence both these membrane potentials. The goal of this research is to show how microcurrent might stimulate physiological potentials in order to support a healthy function of bioelectric fields of cells and organs. In the second part of the article, a study to examine the effects of microcurrent application on the body's response to electric measurements is presented, in particular to a change in voltage-current lag known as a phase angle. The test involved measuring bioimpedance of a person before and after a 30-minute application with microcurrent stimulation. Fifteen healthy subjects were examined through impedance measurements taken on one arm. The results showed a consistent increase in phase angle directly after the stimulation, confirming a widely accepted indication of health improvement on a cellular level. These results are encouraging and justify further investigations on the effect of microcurrent stimulation on the human body in relation to general cellular health and regenerative functions.

Micro-Current Stimulation Suppresses Inflammatory Responses in Peptidoglycan-Treated Raw 264.7 Macrophages and Propionibacterium acnes-Induced Skin Inflammation via TLR2/NF-κB Signaling Pathway

Acne is a common inflammatory disorder of the human skin and a multifactorial disease caused by the sebaceous gland and Propionibacterium acnes (P. acnes). This study aimed to evaluate the anti-inflammatory effect of micro-current stimulation (MC) on peptidoglycan (PGN)-treated raw 264.7 macrophages and P. acnes-induced skin inflammation. To specify the intensity with anti-inflammatory effects, nitric oxide (NO) production was compared according to various levels of MC. As the lowest NO production was shown at an intensity of 50 μA, subsequent experiments used this intensity. The changes of expression of the proteins related to TLR2/NF-κB signaling were examined by immunoblotting. Also, immunofluorescence analysis was performed for observing NF-κB p65 localization. All of the expression levels of proteins regarding TLR2/NF-κB signaling were decreased by the application of MC. Moreover, the application of MC to PGN-treated raw 264.7 cells showed a significant decrease in the amount of nuclear p65-protein. In the case of animal models with P. acnes-induced skin inflammation, various pro-inflammatory cytokines and mediators significantly decreased in MC-applied mice. In particular, the concentration of IL-1β in serum decreased, and the area of acne lesions, decreased from the histological analysis. We suggest for the first time that MC can be a novel treatment for acne.

Treatment of decentralized low-strength livestock wastewater using microcurrent-assisted multi-soil-layering systems: performance assessment and microbial analysis

Discharge of decentralized livestock wastewater without effective treatment has become a common problem in rural areas, threatening the regional water environment. A new microcurrent-assisted multi-soil-layering (MSL) system was developed for treating rural decentralized livestock wastewater. The results showed the highest removal rates of chemical oxygen demand (COD) and total phosphorus (TP) in MSL systems reached 95.45% and 92.0%, respectively. The removal rate of total nitrogen (TN) in MSL systems ranged from 60 to 75%. The bacterial diversity changes among MSL systems showed that high-level height of bottom submergence had a positive effect on the abundance of denitrifying bacteria, while low-level height of bottom submergence had a positive impact on the abundance of nitrifying bacteria. The effect of low-level external voltage on bacterial abundance was better than that of high-level external voltage. Both high- and low-level influent C/N ratios had no significant effect on bacterial abundance. The metabolism and activity of microorganisms were promoted with microcurrent stimulation from the perspective of increased bacterial abundance in MSL systems with improved treatment performance.