Reduction of Edema and Pain in Transcutaneous Electrical Nerve Stimulation Treated-Arthritic Rat.

Transcutaneous electrical nerve stimulation (TENS) has been used to reduce pain or improve motor function in musculoskeletal and neurological disorders in the clinic. Although some studies have suggested electrotherapy as an intervention for edema, the effects and mechanisms of TENS on inflammation-induced edema remain unclear. Thus, we aimed to investigate the effects of TENS on arthritic pain with edema. 1% carrageenan was injected into the right tibiofemoral joint of 69 male Sprague-Dawley rats (200-250 g). After the development of arthritic pain, low-frequency (4-Hz, Low-TENS, n = 25) and high-frequency (100-Hz, High-TENS, n = 25) TENS with sub-motor threshold or placebo-TENS (n = 19) was applied for 20-min to medio-lateral part of the ipsilateral side. Weight bearing and knee-bend tests were used to assess pain-like behaviors. Also, we examined the size of edema and measured tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1ß) levels in the synovium by western blot. Eight rats in each of the two TENS groups were injected with Naloxone. Edema was reduced in the low- and high-frequency TENS groups at 6-h. TENS-treated rats showed reduced pain in the knee-bend test at 6-h. We observed decreased weight load shifts on the ipsilateral side in TENS groups. Naloxone reduced these effects. TNF-α and IL-1ß expression decreased in the synovial membrane at 6-h. These results suggest that low- and high-frequency TENS have acutely positive effects on inflammatory edema, with the management of arthritic pain and reduction in pro-inflammatory mediators. Therefore, Low-TENS and High-TENS may be useful in treating acute inflammatory pain and edema.

A randomized interventional clinical trial assessing the safety and effectiveness of PeaNoc XL tablets in managing joint pain and inflammation in arthritis patients.

Background: Globally, alternative medicine is used widely by most patients for several health challenges. To evaluate the effectiveness and safety of PeaNoc XL Tablet in managing pain and inflammation, a randomized clinical trial and systematic study was designed. PeaNoc XL Tablet has been widely utilized for pain and inflammation management, but no previous studies have examined its efficacy and safety. The aim of this study was to determine the clinical effectiveness and safety profile of PeaNoc XL in patients with arthritis experiencing joint pain and inflammation. Methods: A randomized, controlled, and an open-label trial was conducted. A total of 155 patients (18 to 60 years) with arthritis were enrolled for participation. Using computer-generated random sequences, the study population was divided into two groups in a randomized manner. Group A received Standard therapy and Group B received Standard therapy with PeaNoc XL Tablet 400mg (two tablets OD after food). Results: Out of 155 patients, a total of 83 individuals were excluded from the study, leaving 72 patients who were randomly assigned to either Group A (n=36) or Group B (n=36). The administration of PeaNoc XL as an adjunct to standard therapy resulted in a significant reduction in levels of TNF-α (P<0.01), IL-1ß (P<0.001), IL-6 (P<0.01), and CRP (P<0.01) in arthritis patients experiencing joint pain and inflammation. Conversely, no notable differences were observed from the baseline in the standard therapy group. Conclusions: After 12 weeks of supplementation of PeaNoc XL tablets, as an add-on therapy helps in the reduction of pain score, joint stiffness, and physical stiffness. Trial registration:  CTRI/2022/10/046693.

Brain mapping inflammatory-arthritis-related fatigue in the pursuit of novel therapeutics.

Despite developments in pharmacological treatments, chronic fatigue is an unresolved issue for most people with inflammatory arthritis that severely disrupts their personal and working lives. Fatigue in these patients is not strongly linked with peripheral disease activity but is associated with CNS-derived symptoms such as chronic pain, sleep disturbance, and depression. Therefore, a neurobiological basis should be considered when pursuing novel fatigue-specific therapeutics. In this Review, we focus on clinical imaging biomarkers that map candidate brain regions and are crucial in fatigue pathophysiology. We then evaluate neuromodulation techniques that could affect these candidate brain regions and are potential treatment strategies for fatigue in patients with inflammatory arthritis. We delineate work that is still required for neuroimaging and neuromodulation to eventually become part of a clinical pathway to treat and manage fatigue.

Activation of Hypothalamic AMP-Activated Protein Kinase Ameliorates Metabolic Complications of Experimental Arthritis.

OBJECTIVE: To investigate whether thermogenesis and the hypothalamus may be involved in the physiopathology of experimental arthritis (EA). METHODS: EA was induced in male Lewis rats by intradermal injection of Freund's complete adjuvant (CFA). Food intake, body weight, plasma cytokines, thermographic analysis, gene and protein expression of thermogenic markers in brown adipose tissue (BAT) and white adipose tissue (WAT), and hypothalamic AMP-activated protein kinase (AMPK) were analyzed. Virogenetic activation of hypothalamic AMPK was performed. RESULTS: We first demonstrated that EA was associated with increased BAT thermogenesis and browning of subcutaneous WAT leading to elevated energy expenditure. Moreover, rats experiencing EA showed inhibition of hypothalamic AMPK, a canonical energy sensor modulating energy homeostasis at the central level. Notably, specific genetic activation of AMPK in the ventromedial nucleus of the hypothalamus (a key site modulating energy metabolism) reversed the effect of EA on energy balance, brown fat, and browning, as well as promoting amelioration of synovial inflammation in experimental arthritis. CONCLUSION: Overall, these data indicate that EA promotes a central catabolic state that can be targeted and reversed by the activation of hypothalamic AMPK. This might provide new therapeutic alternatives to treat rheumatoid arthritis (RA)-associated metabolic comorbidities, improving the overall prognosis in patients with RA.

Significance of Interleukin (IL)-4 and IL-13 in Inflammatory Arthritis.

Interleukin (IL)-4 and IL-13 belong to the T helper 2 (Th2) cytokine family, along with IL-3, IL-5, and IL-9. These cytokines are key mediators of allergic inflammation. They have important immunomodulatory activities and exert influence on a wide variety of immune cells, such as B cells, eosinophils, basophils, monocytes, fibroblasts, endothelial cells, airway epithelial cells, smooth muscle cells, and keratinocytes. Recent studies have implicated IL-4 and IL-13 in the development of various autoimmune diseases. Additionally, these cytokines have emerged as potential players in pathogenesis of inflammatory arthritis. Recent findings suggest that the IL-4 and IL-13 might play a significant role in the downregulation of inflammatory processes underlying RA pathology, and beneficially modulate the course of the disease. This review summarizes the biological features of the IL-4 and IL-13 and provides current knowledge regarding the role of these cytokines in inflammatory arthritis.

Effect of Ginseng Extracts on the Improvement of Osteopathic and Arthritis Symptoms in Women with Osteopenia: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

Ginsenosides are active compounds that are beneficial to bone metabolism and have anti-osteoporosis properties. However, very few clinical investigations have investigated the effect of ginseng extract (GE) on bone metabolism. This study aims to determine the effect of GE on improving bone metabolism and arthritis symptoms in postmenopausal women with osteopenia. A 12-week randomized, double-blind, placebo-controlled clinical trial was conducted. A total of 90 subjects were randomly divided into a placebo group, GE 1 g group, and GE 3 g group for 12 weeks based on the random 1:1:1 assignment to these three groups. The primary outcome is represented by bone metabolism indices consisting of serum osteocalcin (OC), urine deoxypyridinoline (DPD), and DPD/OC measurements. Secondary outcomes were serum CTX, NTX, Ca, P, BsALP, P1NP, OC/CTX ratio, and WOMAC index. The GE 3 g group had a significantly increased serum OC concentration. Similarly, the GE 3 g group showed a significant decrease in the DPD/OC ratio, representing bone resorption and bone formation. Moreover, among all the groups, the GE 3 g group demonstrated appreciable improvements in the WOMAC index scores. In women with osteopenia, intake of 3 g of GE per day over 12 weeks notably improved the knee arthritis symptoms with improvements in the OC concentration and ratios of bone formation indices like DPD/OC.

The effects of manual therapy and exercises on pain, muscle strength, joint health, functionality and quality of life in haemophilic arthropathy of the elbow joint: A randomized controlled pilot study.

INTRODUCTION: Effective physiotherapy interventions are required for haemophilic arthropathy (HA) of the elbow due to its biomechanical differences and contribution to upper limb functionality. AIM: To investigate the effects of manual therapy & exercises on bleeding frequency, pain, range of motion (ROM), strength, joint health, functionality and quality of life (QoL) in HA of the elbow. METHODS: Seventeen participants with HA of the elbow were randomized as Manual Therapy & Exercises Group (MTEG = 9) and Home Exercises Group (HEG = 8). Soft tissue mobilization, joint traction (grade I-II) and Mulligan's mobilization with movement as manual therapy, and stretching/strengthening exercises were applied to MTEG, while HEG had only same exercises as home programme. The interventions lasted 3 days/weekly for 5 weeks. Bleeding frequency was evaluated with patients' records; pain with Numeric Pain Scale; ROM with goniometer; strength with digital dynamometer; joint health with HJHS; functionality with Quick-Disability of Arm, Shoulder and Hand questionnaire; and QoL with Oxford Elbow Score. RESULTS: Bleeding frequency and activity pain were decreased, while elbow ROMs and flexor strength were increased in MTEG (P Ë‚ 0.05). Also significantly improvements were seen in joint health, functionality and QoL in MTEG. HEG showed improvements in activity pain, QoL and some ROMs. MTEG had better results in ROMs, joint health and functionality (P Ë‚ 0.05). CONCLUSION: Manual therapy & exercises may be used without causing bleeding and pain to increase the functionality, joint health and QoL, and is superior to home exercise for joint health and functionality. Home exercises may be ameliorated in pain, QoL and some ROMs.

Hong-Hui-Xiang Alleviates Pain Hypersensitivity in a Mouse Model of Monoarthritis.

Background: Hong-Hui-Xiang (HHX) is a sterilized aqueous solution extracted from Illicium lanceolatum A.C. Smith widely used for pain relief in China. Despite its history, it is not well understood. In the present study, we used a mouse model of arthritic knee pain to investigate the antinociceptive effects of HHX and its potential side effects on weight and respiratory function, as well as on the liver, kidney, and heart. Methods: Mice were randomly assigned to four groups: saline and HHX at three doses (1 µl, 10 µl, and 50 µl). Each group was randomly divided to two subgroups: saline and CFA. After the first injection of HHX or saline on day 7, mechanical hyperalgesia was tested via the hind paw. Only after the tests had established that the analgesic effect had subsided was the next injection administered. A total of five injections were administered. Blood, knee joints, and other organs were collected for histopathological observation and biochemical detection. Objectives: We found that mechanical threshold of hind paw increased 2 h after of the initial injection HHX (10 µl and 50 µl), which lasted for at least 3 h. The analgesic effect lasted for three days after the second injection on day 8 and was approximately maintained for five days each time after the third injection. We also found a reduction in the diameter of the knee joint and suppression of synovial inflammation in response to treatment of HHX (10 µl and 50 µl). Meanwhile, HHX had no toxic effects on the liver, kidneys, and heart via histological and biochemical assays in all groups. Conclusion: HHX exerts antinociceptive and anti-inflammatory effects in a mouse model of arthritic knee pain. There were no obvious side effects on the liver, kidneys, or heart.

A fully human anti-BMP6 antibody reduces the need for erythropoietin in rodent models of the anemia of chronic disease.

Recombinant erythropoietin (EPO) and iron substitution are a standard of care for treatment of anemias associated with chronic inflammation, including anemia of chronic kidney disease. A black box warning for EPO therapy and concerns about negative side effects related to high-dose iron supplementation as well as the significant proportion of patients becoming EPO resistant over time explains the medical need to define novel strategies to ameliorate anemia of chronic disease (ACD). As hepcidin is central to the iron-restrictive phenotype in ACD, therapeutic approaches targeting hepcidin were recently developed. We herein report the therapeutic effects of a fully human anti-BMP6 antibody (KY1070) either as monotherapy or in combination with Darbepoetin alfa on iron metabolism and anemia resolution in 2 different, well-established, and clinically relevant rodent models of ACD. In addition to counteracting hepcidin-driven iron limitation for erythropoiesis, we found that the combination of KY1070 and recombinant human EPO improved the erythroid response compared with either monotherapy in a qualitative and quantitative manner. Consequently, the combination of KY1070 and Darbepoetin alfa resulted in an EPO-sparing effect. Moreover, we found that suppression of hepcidin via KY1070 modulates ferroportin expression on erythroid precursor cells, thereby lowering potentially toxic-free intracellular iron levels and by accelerating erythroid output as reflected by increased maturation of erythrocyte progenitors. In summary, we conclude that treatment of ACD, as a highly complex disease, becomes more effective by a multifactorial therapeutic approach upon mobilization of endogenous iron deposits and stimulation of erythropoiesis.

Attenuation of the Diffuse Noxious Inhibitory Controls in Chronic Joint Inflammatory Pain Is Accompanied by Anxiodepressive-Like Behaviors and Impairment of the Descending Noradrenergic Modulation.

The noradrenergic system is paramount for controlling pain and emotions. We aimed at understanding the descending noradrenergic modulatory mechanisms in joint inflammatory pain and its correlation with the diffuse noxious inhibitory controls (DNICs) and with the onset of anxiodepressive behaviours. In the complete Freund's adjuvant rat model of Monoarthritis, nociceptive behaviors, DNICs, and anxiodepressive-like behaviors were evaluated. Spinal alpha2-adrenergic receptors (a2-AR), dopamine beta-hydroxylase (DBH), and noradrenaline were quantified concomitantly with a2-AR pharmacologic studies. The phosphorylated extracellular signal-regulated kinases 1 and 2 (pERK1/2) were quantified in the Locus coeruleus (LC), amygdala, and anterior cingulate cortex (ACC). DNIC was attenuated at 42 days of monoarthritis while present on days 7 and 28. On day 42, in contrast to day 28, noradrenaline was reduced and DBH labelling was increased. Moreover, spinal a2-AR were potentiated and no changes in a2-AR levels were observed. Additionally, at 42 days, the activation of ERKs1/2 was increased in the LC, ACC, and basolateral amygdala. This was accompanied by anxiety- and depressive-like behaviors, while at 28 days, only anxiety-like behaviors were observed. The data suggest DNIC is attenuated in prolonged chronic joint inflammatory pain, and this is accompanied by impairment of the descending noradrenergic modulation and anxiodepressive-like behaviors.

Understanding the Molecular Mechanisms Underlying the Pathogenesis of Arthritis Pain Using Animal Models.

Arthritis, including osteoarthritis (OA) and rheumatoid arthritis (RA), is the leading cause of years lived with disability (YLD) worldwide. Although pain is the cardinal symptom of arthritis, which is directly related to function and quality of life, the elucidation of the mechanism underlying the pathogenesis of pain in arthritis has lagged behind other areas, such as inflammation control and regulation of autoimmunity. The lack of therapeutics for optimal pain management is partially responsible for the current epidemic of opioid and narcotic abuse. Recent advances in animal experimentation and molecular biology have led to significant progress in our understanding of arthritis pain. Despite the inherent problems in the extrapolation of data gained from animal pain studies to arthritis in human patients, the critical assessment of molecular mediators and translational studies would help to define the relevance of novel therapeutic targets for the treatment of arthritis pain. This review discusses biological and molecular mechanisms underlying the pathogenesis of arthritis pain determined in animal models of OA and RA, along with the methodologies used.

The P2X7 Receptor, Cathepsin S and Fractalkine in the Trigeminal Subnucleus Caudalis Signal Persistent Hypernociception in Temporomandibular Rat Joints.

Temporomandibular joint (TMJ) is frequently involved with rheumatoid arthritis with a high prevalence that could result in a chronic pain state. Once the disease is established in the joint, the antigen-specific immune reaction initiates a neuro-immune cascade of events that causes sensitization of the central nervous system. This study establishes animal experimental models that evaluate the chronicity of albumin-induced arthritis hypernociception in the TMJ. Antigen-induced arthritis was generated in rats with methylated bovine serum albumin (mBSA) diluted in complete Freund's. Intra-articular injection of mBSA (10 µg/TMJ/week) during 3 weeks resulted in a persistent inflammatory hypernociception which was characterized by an inflammatory episode characterized by the increased of lymphocytes, macrophages and pro-inflammatory interleukins IL-12 and IL-18. The persistent model of inflammatory hypernociception induced by arthritis in the TMJ elicited protein levels of P2X7 receptors, cathepsin S and fractalkine in the trigeminal subnucleus caudalis. Overall, the results of the present work suggest that a persistent inflammatory hypernociception of albumin-induced arthritis in the TMJ leads to the activation of the central nervous system signaling by P2X7/cathepsin S/fractalkine pathway.

Targeting IgG in Arthritis: Disease Pathways and Therapeutic Avenues.

Rheumatoid arthritis (RA) is a polygenic and multifactorial syndrome. Many complex immunological and genetic interactions are involved in the final outcome of the clinical disease. Autoantibodies (rheumatoid factors, anti-citrullinated peptide/protein antibodies) are present in RA patients' sera for a long time before the onset of clinical disease. Prior to arthritis onset, in the autoantibody response, epitope spreading, avidity maturation, and changes towards a pro-inflammatory Fc glycosylation phenotype occurs. Genetic association of epitope specific autoantibody responses and the induction of inflammation dependent and independent changes in the cartilage by pathogenic autoantibodies emphasize the crucial contribution of antibody-initiated inflammation in RA development. Targeting IgG by glyco-engineering, bacterial enzymes to specifically cleave IgG/alter N-linked Fc-glycans at Asn 297 or blocking the downstream effector pathways offers new avenues to develop novel therapeutics for arthritis treatment.

Proteinases and their receptors in inflammatory arthritis: an overview.

Proteinases are enzymes with established roles in physiological and pathological processes such as digestion and the homeostasis, destruction and repair of tissues. Over the past few years, the hormone-like properties of circulating proteinases have become increasingly appreciated. Some proteolytic enzymes trigger cell signalling via proteinase-activated receptors, a family of G protein-coupled receptors that have been implicated in inflammation and pain in inflammatory arthritis. Proteinases can also regulate ion flux owing to the cross-sensitization of transient receptor potential cation channel subfamily V members 1 and 4, which are associated with mechanosensing and pain. In this Review, the idea that proteinases have the potential to orchestrate inflammatory signals by interacting with receptors on cells within the synovial microenvironment of an inflamed joint is revisited in three arthritic diseases: osteoarthritis, spondyloarthritis and rheumatoid arthritis. Unanswered questions are highlighted and the therapeutic potential of modulating this proteinase-receptor axis for the management of disease in patients with these types of arthritis is also discussed.

Effects of tofacitinib in early arthritis-induced bone loss in an adjuvant-induced arthritis rat model.

Objectives: The main goal of this work was to analyse how treatment intervention with tofacitinib prevents the early disturbances of bone structure and mechanics in the rat model of adjuvant-induced arthritis. This is the first study to access the impact of tofacitinib on the skeletal bone effects of inflammation. Methods: Fifty Wistar rats with adjuvant-induced arthritis were randomly housed in experimental groups, as follows: non-arthritic healthy group (n = 20); arthritic non-treated group (n = 20); and 10 animals undergoing tofacitinib treatment. Rats were monitored during 22 days after disease induction for the inflammatory score, ankle perimeter and body weight. Healthy non-arthritic rats were used as controls for comparison. After 22 days of disease progression, rats were killed and bone samples collected for histology, micro-CT, three-point bending and nanoindentation analysis. Blood samples were also collected for quantification of bone turnover markers and systemic cytokines. Results: At the tissue level, measured by nanoindentation, tofacitinib increased bone cortical and trabecular hardness. However, micro-CT and three-point bending tests revealed that tofacitinib did not reverse the effects of arthritis on the cortical and trabecular bone structure and on mechanical properties. Conclusion: Possible reasons for these observations might be related to the mechanism of action of tofacitinib, which leads to direct interactions with bone metabolism, and/or to the kinetics of its bone effects, which might need longer exposure.

Synthesis and Evaluation of a Sodium Alginate-4-Aminosalicylic Acid Based Microporous Hydrogel for Potential Viscosupplementation for Joint Injuries and Arthritis-Induced Conditions.

A microporous hydrogel was developed using sodium alginate (alg) and 4-aminosalicylic acid (4-ASA). The synthesized hydrogel was characterized using various analytical techniques such as Fourier transform infrared spectroscopy (FTIR), Carbon-13 nuclear magnetic resonance (13C-NMR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). Additonal carboxyl and hydroxyl functional groups of 4-ASA provided significant lubrication and stress-triggered sol-gel transition to the conjugated hydrogel. In addition, cytotoxicity analysis was undertaken on the conjugated hydrogel using human dermal fibroblast-adult (HDFa) cells, displaying non-toxic characteristics. Drug release profiles displaying 49.6% in the first 8 h and 97.5% within 72 h, similar to the native polymer (42.8% in first 8 h and 90.1% within 72 h). Under applied external stimuli, the modified hydrogel displayed significant gelling properties and structure deformation/recovery behaviour, confirmed using rheological evaluation (viscosity and thixotropic area of 8095.3 mPas and 26.23%, respectively). The modified hydrogel, thus, offers great possibility for designing smart synovial fluids as a biomimetic aqueous lubricant for joint-related injuries and arthritis-induced conditions. In addtion, the combination of thixotropy, non-toxicity, and drug release capabilities enables potential viscosupplementation for clinical application.

The atypical receptor CCRL2 is required for CXCR2-dependent neutrophil recruitment and tissue damage.

CCRL2 is a 7-transmembrane domain receptor that shares structural and functional similarities with the family of atypical chemokine receptors (ACKRs). CCRL2 is upregulated by inflammatory signals and, unlike other ACKRs, it is not a chemoattractant-scavenging receptor, does not activate ß-arrestins, and is widely expressed by many leukocyte subsets. Therefore, the biological role of CCRL2 in immunity is still unclear. We report that CCRL2-deficient mice have a defect in neutrophil recruitment and are protected in 2 models of inflammatory arthritis. In vitro, CCRL2 was found to constitutively form homodimers and heterodimers with CXCR2, a main neutrophil chemotactic receptor. By heterodimerization, CCRL2 could regulate membrane expression and promote CXCR2 functions, including the activation of ß2-integrins. Therefore, upregulation of CCRL2 observed under inflammatory conditions is functional to finely tune CXCR2-mediated neutrophil recruitment at sites of inflammation.

Controlled release of optimized electroporation enhances the transdermal efficiency of sinomenine hydrochloride for treating arthritis in vitro and in clinic.

Sinomenine hydrochloride (SH) is an ideal drug for the treatment of rheumatoid arthritis and osteoarthritis. However, high plasma concentration of systemically administered SH can release histamine, which can cause rash and gastrointestinal side effects. Topical delivery can increase SH concentration in the synovial fluid without high plasma level, thus minimizing systemic side effects. However, passive diffusion of SH was found to be inefficient because of the presence of the stratum corneum layer. Therefore, an effective method is required to compensate for the low efficiency of SH passive diffusion. In this study, transdermal experiments in vitro and clinical tests were utilized to explore the optimized parameters for electroporation of topical delivery for SH. Fluorescence experiment and hematoxylin and eosin staining analysis were performed to reveal the mechanism by which electroporation promoted permeation. In vitro, optimized electroporation parameters were 3 KHz, exponential waveform, and intensity 10. Using these parameters, transdermal permeation of SH was increased by 1.9-10.1 fold in mice skin and by 1.6-47.1 fold in miniature pig skin compared with passive diffusion. After the electroporation stimulation, the intercellular intervals and epidermal cracks in the skin increased. In clinical tests, SH concentration in synovial fluid was 20.84 ng/mL after treatment with electroporation. Therefore, electroporation with optimized parameters could significantly enhance transdermal permeation of SH. The mechanism by which electroporation promoted permeation was that the electronic pulses made the skin structure looser. To summarize, electroporation may be an effective complementary method for transdermal permeation of SH. The controlled release of electroporation may be a promising clinical method for transdermal drug administration.