Photobiomodulation effects in metalloproteinases expression in zymosan-induced arthritis.

Matrix metalloproteinases (MMPs) play a crucial role in the degenerative course of rheumatic disorders. They are responsible for cartilage and other joint-associated tissues breakdown. Amid arthritis treatments, photobiostimulation (PBM), a non-thermal and non-invasive low-power laser application, appears to be an outstanding therapy alternative once it has succeeded in MMPs modulation. Thus, this study aimed to evaluate the PBM effects of low infrared laser (830 nm), testing two different energy densities (3 and 30 Jcm-2) in MMP-2, MMP-9, MMP-13, and MMP-14 as well as the inhibitor TIMP-2 expressions using zymosan-induced arthritis model. C57BL/6 mice were distributed into four groups (n = 8): zymosan-induced arthritis without treatment; zymosan-induced arthritis and dexamethasone-treated; zymosan-induced arthritis and PBM at energy density of 3 Jcm-2 treated; and zymosan-induced arthritis and PBM at energy density of 30 Jcm-2 treated. MMPs and TIMP-2 mRNA relative levels by qRT-PCR and proteins expression by immunohistochemical and Western blotting techniques were performed after PBM treatment in the inflamed joint. Our results demonstrated PBM could modulate both mRNA relative levels and proteins expression of the MMP-2, -9, -13, -14, and TIMP-2 in joint tissues, decreasing MMP-9 protein expression and increasing TIMP-2 protein expression. PBM promotes a better arthritis prognostic, modulating metalloproteinase and its inhibitor, especially MMP-9 and TIMP-2 protein expression that is important inflammatory markers. These findings may also corroborate that PBM may regulate MMPs expression using different pathways.

Photobiostimulation activity of different low-level laser dosage on masticatory muscles and temporomandibular joint in an induced arthritis rat model.

This study aimed to investigate the anti-inflammatory effects of different dosage of low-level laser therapy (LLLT) in an experimental model of temporomandibular joint (TMJ) arthritis. One hundred male Wistar rats were used and divided into the following groups: CG, control group; AG, animals group with left TMJ arthritis induced by intra-articular injection of Complete Freund's adjuvant - CFA; LG5, LG10 and LG20 - animals with arthritis and treated with LLLT at doses 5, 10, and 20 J/cm2, respectively. Morphological analysis was performed by TMJ histological sections stained with hematoxylin-eosin (HE), picrosirius (PSR), and toluidine blue (TB), as well as histomorphometric evaluation of cartilage, articular disc, and masticatory muscles. The amount of feed consumed within 3 weeks was evaluated, and biochemical analysis of TMJ tissues included measurement of sulfated glycosaminoglycans (GAGs), matrix metalloproteinases (MMPs) 2 and 9 zymography, and ELISA for cytokines IL-6, TNF-α, and IL-1ß. Only the 20 J/cm2 dose promoted higher feed intake compared to AG. On the other hand, all LLLT doses promoted better organization of articular disc collagen fibers, greater number of proteoglycans in articular cartilage, increased area and diameter of left lateral pterygoid fibers, reduced latent and active MMP 9 and 2 activity, and lower IL-1ß concentration compared to AG. Considering the study limitations, it was observed that LLLT treatments were effective in protecting and tissue cleansing joint structures, accelerating tissue repair, especially at lower doses.

Outpatient treatment for haemophilic arthropathy with radiosynovectomy: Radiation dose to family members.

One of the key features of good practice in medicine is the doctor-patient communication. Radiation protection standards for radiosynovectomy (RS) is limited. Yttrium-90 is a beta-emitting radioisotope used in RS to treat joint pain from haemophilic arthritis. ICRP 94 states that if a patient is treated with up to 200 MBq, there is no need for further precautions when it comes to public exposure, however, activities can go up to 370 MBq in RS for the knee. This study analysed 119 family members' safety (16.7% pregnant women). The ambient dose equivalent rate was measured within four distances. A survey was carried analysing risk groups and time spent next to patients. Results showed that family members should be advised to remain at 1.0 m from the patient to decrease accumulated dose by 97.6%. The dose per activity factors estimated in this study is also a useful tool during the risk assessment and doctor/patient communication. Pamphlets were distributed with radiation protection recommendations. Ambient dose equivalent was low enough to show that RS is a safe procedure for family members, which is essential to promote adherence to RS in countries where it is needed but not performed due to lack of information on radiation safety.

Barium titanate microparticles as potential carrier platform for lanthanide radionuclides for their use in the treatment of arthritis.

Since the inception of radiation synovectomy, a host of radioactive colloids and microparticles incorporating suitable therapeutic radionuclides have been proposed for the treatment of arthritis. The present article reports the synthesis and evaluation of barium titanate microparticles as an innovative and effective carrier platform for lanthanide radionuclides in the preparation of therapeutic agents for treatment of arthritis. The material was synthesized by mechanochemical route and characterized by X-ray diffraction, scanning electron microscopy, surface area, and particle size distribution analyses. Loading of lanthanide radionuclides (166 Ho, 153 Sm, 177 Lu, and 169 Er) on the microparticles was achieved in high yield (> 95%) resulting in the formulation of loaded particulates with excellent radiochemical purities (> 99%). Radiolanthanide-loaded microparticles exhibited excellent in vitro stability in human serum. In vitro diethylene triamine pentaacetic acid challenge study indicated fairly strong chemical association of lanthanides with barium titanate microparticles. Long-term biodistribution studies carried out after administration of 177 Lu-loaded microparticles into one of the knee joints of normal Wistar rats revealed near-complete retention of the formulation (> 96% of the administered radioactivity) within the joint cavity even 14 days post-administration. The excellent localization of the loaded microparticles was further confirmed by sequential whole-body radio-luminescence imaging studies carried out using 166 Ho-loaded microparticles.

Current role for radioisotope synovectomy.

Radioisotope synovectomy has been extensively used to treat patients with chronic inflammatory joint disease but has moved to a less prominent position since the introduction of new and highly effective drugs. Remaining indications are refractory synovitis, pigmented villonodular synovitis as an adjunct to surgery, and hemophilic arthropathy. The three main radioisotopes used are yttrium-90, rhenium-186, and erbium-189. Radioisotope synovectomy should be performed only by highly experienced professionals, to minimize the risk of injection-related complications. The available safety data, in particular regarding the risk of malignancy, are reassuring. The efficacy of yttrium-90 in chronic inflammatory joint disease remains controversial.

Low-intensity laser therapy efficacy evaluation in mice subjected to acute arthritis condition.

Acute arthritis is an inflammation that affects many joints. The principal treatment options comprise drugs (corticosteroids), invasive and painful surgery. The objective of this study was to evaluate the efficacy of low intensity laser therapy (LILT), a non-invasive treatment, in a murine model of acute inflammation model. 48 mice received a synovial injection of Zymosan A into one knee. Mice were treated with LILT by three different wavelengths, either as a single (S) or dual (D) application immediately after the injury or after 24h following initiation of an inflammatory response. The histological analysis aimed at identifying inflammatory infiltrate and the structure of the articular surfaces as an indicator of a long-term damage due to inflammation. Statistical analysis (Kruskal-Wallis test), did not allow to reject the null hypothesis. However, LILT promoted histological alterations in some treatment groups. Histological evidence (Median and confidence interval) of anti-inflammatory effects was especially noticeable in knees of mice irradiated with lasers emitting moderate intensity and continuous 660nm (S=18.5 (11.4; 27.6); D=16.0 (6.93; 27.0)) and high intensity and pulsed 905nm (S=17.5 (10.2; 24.79), with decrease of the resorbed region. However, the 905nm pulsed laser was responsible for exacerbation of inflammation for multiple LILT sessions with a short delay (D=45.0 (22.84; 63.83)), tending to aggravate the resorption of the articular surface (p<0.05). LILT showed signs of an anti-inflammatory effect when applied once, but promoted increased resorptive area when used for two sessions, indicating the importance of a controlled LILT protocol to reach therapeutic effects.

Hydroxyapatite (HA) microparticles labeled with (32)P - A promising option in the radiation synovectomy for inflamed joints.

In the present article we describe a systematic approach pursued for the synthesis of (32)P-labeled hydroxyapatite (HA) microparticles (1-10µm size range) using no carrier added (NCA) (32)P produced in a nuclear reactor and animal evaluation of its utility as an expected viable radiopharmaceutical for the treatment of pain intensive arthrosis. NCA (32)P was produced via the (32)S(n,p)(32)P route in nuclear reactor with high radionuclidic purity (99.95±0.01%, n=5). Phosphorus-32-labeled hydroxyapatite microparticles (1-10µm size range) were synthesized with high radiochemical purity (99.0±0.3% n=12) under optimized conditions and the formulation showed excellent in vitro stability in saline as well as in rat serum. Intra-articular administration of the radiolabeled particles in the knee joints of normal Wistar rats showed near-complete retention of activity within the synovial cavity upto 1 month post-administration. The radiochemical formulation thus demonstrated promising features as a radiopharmaceutical for treatment of arthritis with excellent logistic advantage for shipment to sites distant from the production facility thanks to the suitable nuclear decay properties of (32)P.

Low-level laser therapy stimulates tissue repair and reduces the extracellular matrix degradation in rats with induced arthritis in the temporomandibular joint.

The objective of this study was to characterize morphological and biochemistry action of low-level laser therapy (LLLT) on induced arthritis in the temporomandibular joint (TMJ) of rats. Twenty-four male Wistar rats were randomly divided into groups with 12 animals each: (AG) group with arthritis induced in the left TMJ and (LG) group with arthritis induced in the left TMJ and treated with LLLT (830 nm, 30 mW, 3 J/cm(2)). Right TMJs in the AG group were used as noninjected control group (CG). Arthritis was induced by intra-articular injection of 50 µl Complete Freund's Adjuvant (CFA) and LLLT began 1 week after arthritis induction. Histopathological analysis was performed using sections stained with hematoxylin-eosin, Toluidine Blue, and picrosirius. Biochemical analysis was determined by the total concentration of sulfated glycosaminoglycans (GAGs) and evaluation of matrix metalloproteinases (MMP-2 and MMP-9). Statistical analysis was performed using paired and unpaired t tests, with p < 0.05. Compared to AG, LG had minor histopathological changes in the TMJ, smaller thickness of the articular disc in the anterior (p < 0.0001), middle (p < 0.0001) and posterior regions (p < 0.0001), high birefringence of collagen fibers in the anterior (p < 0.0001), middle (p < 0.0001) and posterior regions (p < 0.0001) on the articular disc, and statistically lower activity of MMP-2 latent (p < 0.0001), MMP-2 active (P = 0.02), MMP-9 latent (p < 0.0001), and MMP-9 active (p < 0.0001). These results suggest that LLLT can increase the remodeling and enhancing tissue repair in TMJ with induced arthritis.

Protective effect of low-level laser therapy (LLLT) on acute zymosan-induced arthritis.

The aim of this study was to evaluate the effect of low-level laser therapy on acute zymosan-induced arthritis, with respect to the laser action on inflammatory cells influx, release of pro-inflammatory mediators, metalloproteinases activity into the joint cavity and the cartilage repair process. Arthritis was induced in male Wistar rats (250-280 g) by intra-articular injection of zymosan (1 mg dissolved in 50 µl of a sterile saline solution) into one rear knee joint. Animals were irradiated immediately, 1 and 2 h after zymosan administration with a semiconductor laser InGaAIP (660 nm, 10 mW, 2.5 J/cm(2), 10 s). In the positive control group, animals were injected with the anti-inflammatory drug dexamethasone 1 h prior to the zymosan administration. Treatment with laser significantly inhibited leukocytes influx, the release of IL-1 and IL-6 and also the activity of metalloproteinase-2 and 9, into the joint cavity. In conclusion, laser therapy was effective in reducing inflammation to sites of injury and inhibit activation of proteases (gelatinase) suggesting less degradation of collagen tissue in experimental model of acute arthritis.

Can osteoarthritis be treated with light?

Osteoarthritis is becoming more problematic as the population ages. Recent reports suggest that the benefit of anti-inflammatory drugs is unimpressive and the incidence of side effects is worrying. Low-level laser (light) therapy (LLLT) is an alternative approach with no known side effects and with reports of substantial therapeutic efficacy in osteoarthritis. In this issue of Arthritis Research & Therapy, Alves and colleagues used a rat model of osteoarthritis produced by intra-articular injection of the cartilage-degrading enzyme papain to test 810-nm LLLT. A single application of LLLT produced significant reductions in inflammatory cell infiltration and inflammatory cytokines 24 hours later. A lower laser power was more effective than a higher laser power. However, more work is necessary before the title question can be answered in the affirmative.

Effect of low-level laser therapy on the expression of inflammatory mediators and on neutrophils and macrophages in acute joint inflammation.

INTRODUCTION: Inflammation of the synovial membrane plays an important role in the pathophysiology of osteoarthritis (OA). The synovial tissue of patients with initial OA is characterized by infiltration of mononuclear cells and production of proinflammatory cytokines and other mediators of joint injury. The objective was to evaluate the effect of low-level laser therapy (LLLT) operating at 50 mW and 100 mW on joint inflammation in rats induced by papain, through histopathological analysis, differential counts of inflammatory cells (macrophages and neutrophils), as well as gene expression of interleukin 1-beta and 6 (IL-1ß and IL-6), and protein expression of tumor necrosis factor alpha (TNFα). METHODS: Male Wistar rats (n = 60) were randomly divided into four groups of 15 animals, namely: a negative control group; an inflammation injury positive control group; a 50 mW LLLT group, subjected to injury and treated with 50 mW LLLT; and a 100 mW LLLT group, subjected to injury and treated with 100 mW LLLT. The animals were subject to joint inflammation (papain solution, 4%) and then treated with LLLT (808 nm, 4 J, 142.4 J/cm(2), spot size 0.028 for both groups). On the day of euthanasia, articular lavage was collected and immediately centrifuged; the supernatant was saved for analysis of expression of TNFα protein by enzyme-linked immunosorbent assay and expression of IL-1ß and IL-6 mRNA by real-time polymerase chain reaction. A histologic examination of joint tissue was also performed. For the statistical analysis, analysis of variance with Tukey's post-hoc test was used for comparisons between each group. All data are expressed as mean values and standard deviation, with P < 0.05. RESULTS: Laser treatment with 50 mW was more efficient than 100 mW in reducing cellular inflammation, and decreased the expression of IL-1ß and IL-6. However, the 100 mW treatment led to a higher reduction of TNFα compared with the 50 mW treatment. CONCLUSIONS: LLLT with 50 mW was more efficient in modulating inflammatory mediators (IL-1ß, IL-6) and inflammatory cells (macrophages and neutrophils), which correlated with the histology that showed a reduction in the inflammatory process.

Reduction of arthritic symptoms by low dose radiation therapy (LD-RT) is associated with an anti-inflammatory phenotype.

PURPOSE: The aim of this paper was to provide an integrative mechanistic appraisal to account for consistent observations of protective effects of ionizing radiation on the occurrence/ progression of arthritis in multiple animal models. MATERIALS AND METHODS: A critical analysis of the biomedical literature was undertaken to assess mechanisms by which low doses of ionizing radiation prevent and/or reduce the occurrence of experimental-induced arthritis in animal models. RESULTS: Detailed mechanistic-related research indicates that low doses of ionizing radiation induce a highly integrated multiple pathway process that results in the formation of a generalized anti-inflammatory phenotype which can both prevent the occurrence of arthritic changes and/or reverse such effects. CONCLUSIONS: The manifestation of the anti-inflammatory features occurred within the context of highly consistent hormetic (i.e., biphasic dose) responses across studies, biological models and mechanisms. The reduction of multiple bioindicators of experimentally-induced arthritis by exposure to low doses of ionizing radiation was associated with the occurrence of a generalized anti-inflammatory phenotype.

Low dose radiation therapy (LD-RT) is effective in the treatment of arthritis: animal model findings.

PURPOSE: This paper provides a critical assessment of the hypothesis that low doses of ionizing radiation may be potentially effective in the treatment of inflammatory conditions, with particular focus on arthritis. MATERIALS AND METHODS: A critical review of the biomedical literature was undertaken to assess whether low doses of ionizing radiation may affect the progression of experimentally-induced arthritis using multiple animal models. RESULTS: The findings indicate that low doses of ionizing radiation were effective in alleviating the occurrence of clinical symptoms of arthritis in five complementary experimental models of arthritis. CONCLUSIONS: Consistent findings by multiple research groups indicate that low doses of ionizing radiation can be highly effective in reducing a broad range of arthritic changes in multiple animal models in a manner quantitatively similar to that of well known pharmaceutical agents.

Meta-analysis of pain relief effects by laser irradiation on joint areas.

BACKGROUND: Laser therapy has been proposed as a physical therapy for musculoskeletal disorders and has attained popularity because no side effects have been reported after treatment. However, its true effectiveness is still controversial because several clinical trials have reported the ineffectiveness of lasers in treating pain. METHODS: In this systematic review, we investigate the clinical effectiveness of low-level laser therapy (LLLT) on joint pain. Clinical trials on joint pain satisfying the following conditions are included: the laser is irradiated on the joint area, the PEDro scale score is at least 5, and the effectiveness of the trial is measured using a visual analogue scale (VAS). To estimate the overall effectiveness of all included clinical trials, a mean weighted difference in change of pain on VAS was used. RESULTS: MEDLINE is the main source of the literature search. After the literature search, 22 trials related to joint pain were selected. The average methodological quality score of the 22 trials consisting of 1014 patients was 7.96 on the PEDro scale; 11 trials reported positive effects and 11 trials reported negative effects. The mean weighted difference in change of pain on VAS was 13.96 mm (95% CI, 7.24-20.69) in favor of the active LLLT groups. When we only considered the clinical trials in which the energy dose was within the dose range suggested in the review by Bjordal et al. in 2003 and in World Association for Laser Therapy (WALT) dose recommendation, the mean effect sizes were 19.88 and 21.05 mm in favor of the true LLLT groups, respectively. CONCLUSIONS: The review shows that laser therapy on the joint reduces pain in patients. Moreover, when we restrict the energy doses of the laser therapy into the dose window suggested in the previous study, we can expect more reliable pain relief treatments.

The influence of irradiation on the potential chondroprotective effect of aqueous extract of propolis in rats.

PURPOSE: Cartilage degradation usually results as a consequence of inflammatory processes in the joints. To study this phenomenon experimentally, adjuvant-induced arthritis (AIA) was used as a model of chronic inflammation under the influence of irradiation. The potential chondroprotective effect of 13% aqueous extract of propolis (AEP) in arthritic rats was investigated. MATERIALS AND METHODS: The influence of whole body irradiation on the arthritic inflammatory response was investigated by subjecting rats to a Gamma source before the induction of arthritis. 13% AEP was injected intraperitoneally in a dose of 5 ml/kg and diclofenac was used as reference non-steroidal anti-inflammatory drug (NSAID) in a dose of 3 mg/kg. The chosen parameters for cartilage integrity were glycosaminoglycan (GAG), hydroxyproline contents in cartilage and cartilage oligomeric matrix protein (COMP) in serum. The serum levels of tumour necrosis factor-alpha (TNF-α), nitric oxide (NO) and the oxidative stress biomarkers such as blood glutathione (GSH) and plasma malondialdehyde (MDA) levels. RESULTS: Induction of arthritis led to a reduction in GAG and hydroxyproline content of femoral cartilage and a corresponding rise in COMP in serum. Previous exposure to irradiation resulted in a milder reduction of GAG and hydroxyproline and a lesser rise in COMP. Treatment of arthritic irradiated and non-irradiated rats with 13% AEP markedly prevented the breakdown of cartilage in a much more effective manner than diclofenac. Both AEP and diclofenac were equipotent in reducing the level of TNF-α and were able to normalize NO and the oxidative stress biomarkers in non-irradiated and irradiated arthritic rats. CONCLUSION: The ability of propolis to protect cartilage degradation could therefore prove of value in the treatment of chronic arthritic diseases, offering an advantage over some NSAID, particularly those with a potential detrimental effect on cartilage integrity.

Whole body low dose irradiation improves the course of beginning polyarthritis in human TNF-transgenic mice.

Rheumatoid arthritis (RA) displays a chronic inflammatory joint disease, accompanied by symmetric polyarthritis (PA) which evokes synovial inflammation, cartilage damage, and bone erosion. Patients with RA are routinely treated by immunosuppressive drugs. The therapy of inflammatory diseases and degenerative disorders with Low-dose radiotherapy (LD-RT) (single doses from 0.3 to 1.0 Gy) represents a low cost therapy with low toxicity, and is able to substitute at least in part treatment with drugs. The efficiency of LD-RT has already been proven in several animal models of inducible arthritis. In the present study we used a human TNF transgenic mouse model to examine the effects of LD-RT on PA. We observed a significant temporal improvement of the clinical progression of disease when mice were irradiated at the beginning of the disease. These data emphasize the role of LD-RT in clinical settings to treat patients with chronic and degenerative disorders and diseases.

Effects of laser on the synovial fluid in the inflammatory process of the knee joint of the rabbit.

OBJECTIVE: The purpose of this study was to evaluate the effects of low-level laser (LLL) energy on the clinical signs of inflammation and the cellular composition of synovial fluid (SF) in the inflamed knee of the rabbit. BACKGROUND DATA: There are few findings related to the effects of LLL on SF in inflammatory processes and there is little knowledge about the optimal parameters for reducing joint inflammation. MATERIALS AND METHODS: Inflammation in the right knee of 36 rabbits was induced by intracapsular injection (0.2 mL) of Terebinthina commun (Tc). The animals were randomly assigned to three groups: acute experimental group (AEG), chronic experimental group (CEG), and control group (CG), which only received Tc. Each group was divided in two subgroups of six animals each. The AEG and CEG groups began to receive laser treatment 2 and 5 d after the induction of inflammation, respectively. Laser irradiation at a wavelength of 830 nm, power output of 77 mW, and power density of 27.5 W/cm(2) was applied daily for 7 d for either 0.12 sec or 0.32 sec, resulting in doses of 3.4 J/cm(2) and 8 J/cm(2), respectively. Body mass, joint perimeter, joint temperature, and the morphology of the SF were analyzed. RESULTS: There was no statistically significant differences between groups in the body mass, joint perimeter, and SF morphology. CONCLUSION: Laser irradiation with the selected parameters produced only a few subtle differences in the inflammatory signs and the SF. The lack of effects may have been due to the short irradiation time.