Effect of photobiomodulation therapy on the proliferation phase and wound healing in rats fed with an experimental hypoproteic diet.

Photobiomodulation therapy (PBMT) has been indicated for enforcement on healing skin wounds. This study evaluated the effects of PBMT on the healing of skin wounds during the proliferation phase in rats with a hypoproteic diet. Rats were randomized to one of the following groups (n = 10 per group): (i) injured normoproteic (25% protein) not subjected to PBMT; (ii) injured normoproteic who received PBMT; (iii) injured hypoproteic (8% protein) not subjected to PBMT; and (iv) injured hypoproteic who received PBMT. Rats were submitted to skin wounds and then treated with PBMT (low-level laser therapy: 660 nm, 50 mW, 1.07 W/cm2, 0.028 cm2, 72 J/cm2, 2 J). Analyses were performed at 7 and 14 days of follow-up: semi-quantitative histopathologic analysis, collagen type I and III expressions, immunohistochemical marking for matrix metalloproteinases-3 (MMP-3) and (matrix metalloproteinases-9) MMP-9, and mechanical resistance test. There were significant differences between the normoproteic groups and their respective treated groups (p < 0.05), as well as to treated and untreated hypoproteic groups in histopathologic analysis semi-quantitatively and immunohistochemistry for MMP-3 and 9, in which PBMT was able to decrease immunostaining. Moreover, there was a decrease in collagen deposition with the statistical difference (p < 0.05) for both collagen types III and I. In conclusion, PBMT application was proved effective in the treatment of cutaneous wounds in rats submitted to a hypoproteic diet. These alterations were more salient in the proliferation stage with the reduction of metalloproteinases providing better mechanical resistance of the injured area in the remodeling phase with an intensification of type I collagen.

Photodynamic antimicrobial chemotherapy has an overt killing effect on periodontal pathogens? A systematic review of experimental studies.

The periodontal disease (PD) etiology is mainly associated with some bacterial strains, such as Porphyromonas gingivalis (P. gingivalis). Nonsurgical root scaling (e.g., antibiotics) may achieve a temporary decrease in the P. gingivalis level, yet it cannot eradicate the microorganism. Moreover, antibiotics can lead to bacterial resistance and undesirable side effects. This systematic review was performed to identify animal data defining antimicrobial photodynamic therapy (PACT) role on experimental PD models in the treatment of P. gingivalis. Embase, MEDLINE, and PubMed were examined for studies published from January 1980 to August 2018. MeSH terms and Scopus data were used to find more related keywords. Four studies were selected and reviewed by two independent researches with a structured tool for rating the research quality. The beneficial effect of PACT included reductions in P. gingivalis counts, bleeding on probing, redness, and inflammation on multiple sites (i.e., first molar, dental implants; subgingival; and mandibular premolars). Although our results suggest that PACT displays antimicrobial action on P. gingivalis, thus improving the PD, a nonuniformity in the PACT protocol and the limited number of studies included lead to consider that the bactericidal efficacy of PACT against periodontal pathogens in PD remains unclear.

Incorporation of photobiomodulation therapy into a therapeutic exercise program for knee osteoarthritis: A placebo-controlled, randomized, clinical trial.

OBJECTIVE: To investigate the clinical effects of incorporation of phototherapy in a therapeutic exercise program for individuals with knee osteoarthritis (OA) when compared to a group that received exercise alone and to a group that received exercise + placebo phototherapy. MATERIALS AND METHODS: This is a randomized, blinded and placebo-controlled trial. Thus, sixty male and female individuals aged 40-80 years with knee pain in the previous 6 months participated of the study, with diagnosis of unilateral knee OA based on the criteria established by the American College of Rheumatology and radiographic confirmation and Grades 2 or 3 of the Kellgren-Lawrence Classification. The individuals were equally divided in the groups exercise alone, exercise + active phototherapy (nine-diode cluster device: one 905 nm super-pulsed diode laser, four 875 nm LED and four 640 nm LED; energy per quadrant: 7.85 J; total energy: 23.55 J per session), or exercise + placebo phototherapy. Treatments were performed twice a week for 5 consecutive weeks. Patients were evaluated before and after the sessions of treatment. The outcome measures were: Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Lower Extremity Functional Scale (LEFS), Numerical Rating Pain Scale (NRPS), pressure pain threshold (PPT) in two points of knee, muscle strength, and the Functional Reach Test (FRT). RESULTS: Exercise + active phototherapy was significantly more effective than exercise alone (mean difference [MD] = 2.75, 95% confidence interval [CI] = 3.17 to 2.32) and exercise + placebo phototherapy (MD = 2.38, 95% CI = 2.79 to 1.96) only with regard to the NRPS, considering minimal clinically important difference. No clinical significant results were found for function, the pressure pain threshold, muscle strength or balance. CONCLUSIONS: The combination of phototherapy and an exercise program is effective at reducing pain intensity among individuals with knee osteoarthritis than exercise alone or exercise + placebo phototherapy in a short-term protocol. Lasers Surg. Med. 50:819-828, 2018. © 2018 Wiley Periodicals, Inc.

Can photobiomodulation associated with implantation of mesenchymal adipose-derived stem cells attenuate the expression of MMPs and decrease degradation of type II collagen in an experimental model of osteoarthritis?

This study aimed to determine whether photobiomodulation therapy (PBMT) could improve the bioavailability and chondroprotective benefits of mesenchymal stem cells injected into the knees of rats used as an experimental model of osteoarthritis (OA) as well as reduce the expression of matrix metalloproteinases (MMPs) and degradation of type II collagen (COL2-1) in the cartilage. Adipose-derived stem/stromal cells (ADSCs) were collected from three male Fischer 344 rats and characterized by flow cytometry. Fifty female Fischer 344 rats were distributed into five groups of 10 animals each. These groups were as follows: control, OA, OA PBMT, OA ADSC, and OA ADSC PBMT. OA was induced in the animals using a 4% papain solution. Animals from the OA ADSC and OA ADSC PBMT groups received an intra-articular injection of 10 × 106 ADSCs and were treated with PBMT by irradiation (wavelength: 808 nm, power: 50 mW, energy: 42 J, energy density: 71.2 J/cm2, spot size: 0.028). Euthanasia was performed 7 days after the first treatment. The use of PBMT alone and the injection of ADSCs resulted in downregulation of pro-inflammatory cytokines and MPs in cartilage compared to the OA group. PBMT and ADSCs caused upregulation of tissue inhibitors of MPs 1 and 2 and mRNA and protein expression of COL2-1 in cartilage compared to the OA group. The intra-articular injection of ADSCs and PBMT prevented joint degeneration resulting from COL2-1 degradation and modulated inflammation by downregulating cytokines and MMPs in the OA group.

When is the best moment to apply photobiomodulation therapy (PBMT) when associated to a treadmill endurance-training program? A randomized, triple-blinded, placebo-controlled clinical trial.

Photobiomodulation therapy (PBMT) employing low-level laser therapy (LLLT) and/or light emitting diode therapy (LEDT) has emerged as an electrophysical intervention that could be associated with aerobic training to enhance beneficial effects of aerobic exercise. However, the best moment to perform irradiation with PBMT in aerobic training has not been elucidated. The aim of this study was to assess the effects of PBMT applied before and/or after each training session and to evaluate outcomes of the endurance-training program associated with PBMT. Seventy-seven healthy volunteers completed the treadmill-training protocol performed for 12 weeks, with 3 sessions per week. PBMT was performed before and/or after each training session (17 sites on each lower limb, using a cluster of 12 diodes: 4 × 905 nm super-pulsed laser diodes, 4 × 875 nm infrared LEDs, and 4 × 640 nm red LEDs, dose of 30 J per site). Volunteers were randomized in four groups according to the treatment they would receive before and after each training session: PBMT before + PBMT after, PBMT before + placebo after, placebo before + PBMT after, and placebo before + placebo after. Assessments were performed before the start of the protocol and after 4, 8, and 12 weeks of training. Primary outcome was time until exhaustion; secondary outcome measures were oxygen uptake and body fat. PBMT applied before and after aerobic exercise training sessions (PBMT before + PBMT after group) significantly increased (p < 0.05) the percentage of change of time until exhaustion and oxygen uptake compared to the group treated with placebo before and after aerobic exercise training sessions (placebo before + placebo after group) at 4th, 8th, and 12th week. PBMT applied before and after aerobic exercise training sessions (PBMT before + PBMT after group) also significantly improved (p < 0.05) the percentage of change of body fat compared to the group treated with placebo before and after aerobic exercise training sessions (placebo before + placebo after group) at 8th and 12th week. PBMT applied before and after sessions of aerobic training during 12 weeks can increase the time-to-exhaustion and oxygen uptake and also decrease the body fat in healthy volunteers when compared to placebo irradiation before and after exercise sessions. Our outcomes show that PBMT applied before and after endurance-training exercise sessions lead to improvement of endurance three times faster than exercise only.

Randomized, blinded, controlled trial on effectiveness of photobiomodulation therapy and exercise training in the fibromyalgia treatment.

This study evaluated the role of the phototherapy and exercise training (EXT) as well as the combined treatment in general symptoms, pain, and quality of life in women suffering from fibromyalgia (FM). A total of 160 women were enrolled and measures were carried out in two sets: it was sought to identify the acute effect for a single phototherapy and EXT session (Set 1); long-term effect (10 weeks) of the interventions (Set 2). Phototherapy irradiation was performed at 11 locations in their bodies, employing a cluster with nine diodes (one super-pulsed infrared 905 nm, four light-emitting diodes [LEDs] of 640 nm, and four LEDs of 875 nm, 39.3 J per location). Algometry and VAS instrument were applied to evaluate pain. The FM symptoms were evaluated with Fibromyalgia Impact Questionnaire (FIQ) and Research Diagnostic Criteria (RDC) instruments. Quality of life was assessed through SF-36 survey. Set 1: pain threshold was improved with the phototherapy, and EXT improved the pain threshold for temporomandibular joint (right and left body side) and occipital site (right body side). Set 2: there was improved pain threshold in several tender points with the phototherapy and EXT. There was an overlap of therapies to reduce the tender point numbers, anxiety, depression, fatigue, sleep, and difficulty sleeping on FIQ/RDC scores. Moreover, quality of life was improved with both therapies. The phototherapy and EXT improved the pain threshold in FM women. A more substantial effect was noticed for the combined therapy, in which pain relief was accomplished by improving VAS and FIQ scores as well as quality of life.

Muscle fiber conduction velocity and EMG amplitude of the upper trapezius muscle in healthy subjects after low-level laser irradiation: a randomized, double-blind, placebo-controlled, crossover study.

Although low-level laser therapy (LLLT) is an important resource for the treatment of non-specific neck pain patients, the dose which presents the greatest therapeutic potential for the treatment of this pathology is still unclear. The present study aimed to evaluate the immediate effect of LLLT on the muscle fiber conduction velocity (MFCV) and electromyographic activity (EMG) of the upper trapezius (UT) muscle in healthy individuals. A total of 20 healthy subjects were enrolled in a randomized, double-blind, crossover study. Active LLLT (820 nm wavelength, 30 mW, energy total 18 J) or placebo LLLT (pLLLT) was delivered on the UT muscle. Each subject was subjected to a single session of active LLLT and pLLLT. Surface electromyography (sEMG) signal of the UT muscle was recorded during five different step contractions of shoulder elevation force (10-30% maximal voluntary contraction) pre- and post-LLLT irradiation. The values of MFCV and sEMG global amplitude (RMSG) were used to calculate the effects of LLLT. The results showed no difference in the MFCV comparing the LLLT and pLLLT groups (F = 0.72 p = 0.39, η p2 = 0.004). However, a significant difference was observed in the RMSG between the LLLT and pLLLT (F 1,2 = 16.66; P < 0.0001, η p2 = 0.09). Individuals who received active LLLT presented a significant decrease in RMSG after laser application (F = 61.28; p < 0.0001, η p2 = 0.43). In conclusion, the 820 nm LLLT, with energy total of 18 J, did not alter the MFCV but significantly reduced the sEMG signal amplitude of the upper trapezius muscle in healthy subjects to a level of up to 30% of maximal voluntary contraction.

Predicted Equation for VO2 Based on a 20-Meter Multistage Shuttle Run Test for Children.

This study compared maximum oxygen consumption (VO2max) on a 20-meter multistage shuttle run test (20-Srt) with a cardiopulmonary exercise test (CPET) to determine a VO2max prediction equation for a 20-Srt in children aged 6-10 years. Eighty healthy children performed the CPET on a treadmill, while the 20-Srt took place on a sports court. Heart rate (HR) was measured and the expired gases were continuously measured breath-by-breath using a portable gas analyzer. The VO2max was lower (p<0.05) in CPET than 20-Srt for all, female, and male participants, respectively (46.3±7.9 vs. 48.7±4.6; 42.7±7.8 vs. 46.7±4.8; 49.3±6.8 vs. 50.4±3.9, mL·kg-1·min-1). The standard error estimates were between 3.0 and 3.6 and considered as not clinically relevant if less than 5 mL·kg-1·min-1. The intraclass correlation coefficient between the VO2 in CPET and in 20-Srt was 0.74 (CI95% 0.55-0.84) and considered moderately reliable. The linear multiple regression excluded sex, body mass index and fat-free mass and retained the maximum speed and age in the predictive equation. The 20-Srt estimates the VO2max with moderate reliability and the predictive equation was VO2maxpred=4.302+(maximum speed*5.613)-(age*1.523) for children aged 6-10 years.

What is the best moment to apply phototherapy when associated to a strength training program? A randomized, double-blinded, placebo-controlled trial : Phototherapy in association to strength training.

The effects of phototherapy (or photobiomodulation therapy) with low-level laser therapy (LLLT) and/or light-emitting diodes (LEDs) on human performance improvement have been widely studied. Few studies have examined its effect on muscular training and no studies have explored the necessary moment of phototherapy irradiations (i.e., before and/or after training sessions). The aim of this study was to determine the optimal moment to apply phototherapy irradiation when used in association with strength training. Forty-eight male volunteers (age between 18 to 35 years old) completed all procedures in this study. Volunteers performed the strength training protocol where either a phototherapy and/or placebo before and/or after each training session was performed using cluster probes with four laser diodes of 905 nm, four LEDs of 875 nm, and four LEDs of 640 nm-manufactured by Multi Radiance Medical™. The training protocol duration was 12 weeks with assessments of peak torque reached in maximum voluntary contraction test (MVC), load in 1-repetition maximum test (1-RM) and thigh circumference (perimetry) at larger cross-sectional area (CSA) at baseline, 4 weeks, 8 weeks, and 12 weeks. Volunteers from group treated with phototherapy before and placebo after training sessions showed significant (p < 0.05) changes in MVC and 1-RM tests for both exercises (leg extension and leg press) when compared to other groups. With an apparent lack of side effects and safety due to no thermal damage to the tissue, we conclude that the application of phototherapy yields enhanced strength gains when it is applied before exercise. The application may have additional beneficial value in post-injury rehabilitation where strength improvements are needed.

Effects of low level laser therapy on attachment, proliferation, and gene expression of VEGF and VEGF receptor 2 of adipocyte-derived mesenchymal stem cells cultivated under nutritional deficiency.

Low-level laser therapy (LLLT) has been shown to increase the proliferation of several cell types. We evaluated the effects of LLLT on adhesion, proliferation, and gene expression of vascular endothelial growth factor (VEGF) and type 2 receptor of VEGF (VEGFR2) at mesenchymal stem cells (MSCs) from human (hMSCs) and rat (rMSCs) adipose tissues on nutritional deficiencies. A dose-response curve was performed with cells treated with laser Ga-Al-As (660 nm, 30 mW) at energy of 0.7 to 9 J. Cell adhesion and proliferation were quantified 20, 40, and 60 min after LLLT and 24, 72, and 120 h after cultivation. Gene expression was verified by RT-PCR after 2 h of LLLT. A minor nutritional support caused a significant decrease in proliferation and adhesion of hMSCs and rMSCs. However, at the lowest LLLT dose (0.7 J), we observed a higher proliferation in hMSCs at standard condition shortly after irradiation (24 h). Adhesion was higher in hMSCs cultivated in controlled conditions at higher LLLT doses (3 and 9 J), and rMSCs show a reduction in the adhesion on 1.5 to 9 J. On nutritional deprivation, a 9 J dose was shown to reduce proliferation with 24 h and adhesion to all culture times in rMSCs. VEGF and VEGFR2 were increased after LLLT in both cell types. However, hMSCs under nutritional deprivation showed higher expression of VEGF and its receptor after irradiation with other laser doses. In conclusion, LLLT on human and rat MSCs might upregulate VEGF messenger RNA (mRNA) expression and modulate cell adhesion and proliferation distinctively.

Comparative analysis of low-level laser therapy (660 nm) on inflammatory biomarker expression during the skin wound-repair process in young and aged rats.

The wound-healing process plays an essential role in the protective response to epidermal injury by tissue regeneration. In the elderly, skin functions deteriorate as a consequence of morphological and structural changes. This study aimed to evaluate and compare the effect of low-level laser therapy (LLLT) in cutaneous wound healing in young and aged rats. A total of 60 male rats comprising 30 young (± 30 days) and 30 aged (± 500 days) was used. The animals were divided into four experimental groups and underwent skin wound and/or treatment with LLLT (660 nm, 30 mW, 1.07 W/cm(2), 0.028 cm(2), 72 J/cm(2), and 2 J). Analyses were conducted to verify the effects of LLLT in the tissue repair process, in the gene expression, and protein expression of TNF-α, IL-1ß, and IL-10, obtained in skin wound model. Results showed that there were significant differences between the young control group and the aged control group and their respective treated groups (LLLT young and LLLT aged). We conclude that LLLT has shown to be effective in the treatment of skin wounds in young and aged animals at different stages of the tissue repair process, which suggests that different LLLT dosimetry should be considered in treatment of subjects of different ages. Further clinical trials are needed to confirm these findings in clinical settings.

Phototherapy in skeletal muscle performance and recovery after exercise: effect of combination of super-pulsed laser and light-emitting diodes.

Recent studies with phototherapy have shown positive results in enhancement of performance and improvement of recovery when applied before exercise. However, several factors still remain unknown such as therapeutic windows, optimal treatment parameters, and effects of combination of different light sources (laser and LEDs). The aim of this study was to evaluate the effects of phototherapy with the combination of different light sources on skeletal muscle performance and post-exercise recovery, and to establish the optimal energy dose. A randomized, double-blinded, placebo-controlled trial with participation of 40 male healthy untrained volunteers was performed. A single phototherapy intervention was performed immediately after pre-exercise (baseline) maximum voluntary contraction (MVC) with a cluster of 12 diodes (4 of 905 nm lasers-0.3125 mW each, 4 of 875 nm LEDs-17.5 mW each, and 4 of 670 nm LEDs-15 mW each- manufactured by Multi Radiance Medical™) and dose of 10, 30, and 50 J or placebo in six sites of quadriceps. MVC, delayed onset muscle soreness (DOMS), and creatine kinase (CK) activity were analyzed. Assessments were performed before, 1 min, 1, 24, 48, 72, and 96 h after eccentric exercise protocol employed to induce fatigue. Phototherapy increased (p < 0.05) MVC was compared to placebo from immediately after to 96 h after exercise with 10 or 30 J doses (better results with 30 J dose). DOMS was significantly decreased compared to placebo (p < 0.05) with 30 J dose from 24 to 96 h after exercise, and with 50 J dose from immediately after to 96 h after exercise. CK activity was significantly decreased (p < 0.05) compared to placebo with all phototherapy doses from 1 to 96 h after exercise (except for 50 J dose at 96 h). Pre-exercise phototherapy with combination of low-level laser and LEDs, mainly with 30 J dose, significantly increases performance, decreases DOMS, and improves biochemical marker related to skeletal muscle damage.

Pre-Exercise Infrared Low-Level Laser Therapy (810 nm) in Skeletal Muscle Performance and Postexercise Recovery in Humans, What Is the Optimal Dose? A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.

AIM: This study aimed to evaluate the medium-term effects of low-level laser therapy (LLLT or photobiomodulation) in postexercise skeletal muscle recovery and performance enhancement and to identify the optimal dose of 810 nm LLLT. MATERIALS AND METHODS: A randomized, double-blind, placebo-controlled trial was performed, with voluntary participation of 28 high-level soccer athletes. We analyzed maximum voluntary contraction (MVC), delayed onset muscle soreness (DOMS), creatine kinase (CK) activity, and interleukin-6 (IL-6) expression. The assessments were performed before exercise protocols, after 1 min, and 1, 24, 48, 72, and 96 h after the end of eccentric exercise protocol used to induce fatigue. LLLT was applied before eccentric exercise protocol with a cluster with five diodes, and dose of 10, 30, or 50 J (200 mW and 810 nm) in six sites of quadriceps. RESULTS: LLLT increased (p < 0.05) MVC from immediately after exercise to 24 h with 50 J dose, and from 24 to 96 h with 10 J dose. Both 10 J then 50 J dose decreased (p < 0.05) CK and IL-6 with better results in favor of 50 J dose. However, LLLT had no effect in decreasing DOMS. No differences (p > 0.05) were found for 30 J dose in any of the outcomes measured. CONCLUSIONS: Pre-exercise LLLT, mainly with 50 J dose, significantly increases performance and improves biochemical markers related to skeletal muscle damage and inflammation.

Role of low-level laser therapy on the cardiac remodeling after myocardial infarction: A systematic review of experimental studies.

AIMS: We systematically reviewed the role of low-level laser therapy (LLLT) in cardiac remodeling after myocardial infarction. MAIN METHODS: Literatures were systematically searched in several electronic databases. We included only studies with a well-standardized coronary occlusion model in vivo LLLT application. KEY FINDINGS: After screening, 14 studies were eligible for review. The study heterogeneity was described in terms of rationality, gender, irradiation parameters, treatment numbers and moment of LLLT application. Three studies showed a null role of LLLT on infarct size, and only one study found positive LLLT effects on the cardiac performance. The cardioprotective role of LLLT was mediated by anti-inflammatory, pro-angiogenic and anti-oxidant actions. SIGNIFICANCE: The reduction in infarct size is a major finding. The LLLT cardioprotection may be mediated by several molecular and cellular mechanisms. Although these results are exciting, there are many limitations that must be resolved before LLLT clinical trials.

Effects of exercise training and photobiomodulation therapy (EXTRAPHOTO) on pain in women with fibromyalgia and temporomandibular disorder: study protocol for a randomized controlled trial.

BACKGROUND: Fibromyalgia (FM) is a syndrome most prevalent in women, in whom it is characterized mainly by chronic pain. An important issue is that many patients with FM are reported to have temporomandibular dysfunction (TMD), and the coexistence of these pathologies generates a clinical outcome of high complexity. The literature is unclear regarding an effective therapy for reducing pain in patients with both comorbidities. Exercise training and phototherapy (low-level laser therapy with light-emitting diode) are two of the approaches used to treat pain. Thus, the aim of this study is to assess the potential role of exercise training plus phototherapy in reducing chronic pain in women with FM and TMD. A further aim is to determine whether the interventions can improve quality of life and modulate endogenous serotonin. METHODS/DESIGN: A randomized controlled clinical trial will be conducted. It will involve 60 women ≥ 35 years of age with a diagnosis of FM and TMD. After recruitment, patients will be randomly allocated to one of four groups: a control group (no intervention), a group that will receive a phototherapy intervention (PHO), a group that will be prescribed muscle-stretching, aerobic, and facial exercises (EXT), or a group that will receive phototherapy plus exercise interventions (PHO + EXT). The trial will last 10 weeks, and the following outcomes will be evaluated on two separate occasions (baseline and within 24 h after the last day of the protocol). Pain intensity will be analyzed using a visual analogue scale and the McGill Pain Questionnaire, and pain thresholds will be punctuated using a digital algometer. FM symptoms will be assessed using the Fibromyalgia Impact Questionnaire, and quality of life will be determined with the 36-item Short Form Health Survey. Serotonin levels will be evaluated in salivary samples using a competitive enzyme-linked immunosorbent assay. DISCUSSION: This is the first randomized controlled trial in which the role of phototherapy, exercise training, and a combination of these interventions will be evaluated for chronic pain in patients with FM and TMD. The results will offer valuable clinical evidence for objective assessment of the potential benefits and risks of procedures. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02279225. Registered 27 October 2014.

Amelioration of cardiac function and activation of anti-inflammatory vasoactive peptides expression in the rat myocardium by low level laser therapy.

Low-level laser therapy (LLLT) has been used as an anti-inflammatory treatment in several disease conditions, even when inflammation is a secondary consequence, such as in myocardial infarction (MI). However, the mechanism by which LLLT is able to protect the remaining myocardium remains unclear. The present study tested the hypothesis that LLLT reduces inflammation after acute MI in female rats and ameliorates cardiac function. The potential participation of the Renin-Angiotensin System (RAS) and Kallikrein-Kinin System (KKS) vasoactive peptides was also evaluated. LLLT treatment effectively reduced MI size, attenuated the systolic dysfunction after MI, and decreased the myocardial mRNA expression of interleukin-1 beta and interleukin-6 in comparison to the non-irradiated rat tissue. In addition, LLLT treatment increased protein and mRNA levels of the Mas receptor, the mRNA expression of kinin B2 receptors and the circulating levels of plasma kallikrein compared to non-treated post-MI rats. On the other hand, the kinin B1 receptor mRNA expression decreased after LLLT. No significant changes were found in the expression of vascular endothelial growth factor (VEGF) in the myocardial remote area between laser-irradiated and non-irradiated post-MI rats. Capillaries density also remained similar between these two experimental groups. The mRNA expression of the inducible nitric oxide synthase (iNOS) was increased three days after MI, however, this effect was blunted by LLLT. Moreover, endothelial NOS mRNA content increased after LLLT. Plasma nitric oxide metabolites (NOx) concentration was increased three days after MI in non-treated rats and increased even further by LLLT treatment. Our data suggest that LLLT diminishes the acute inflammation in the myocardium, reduces infarct size and attenuates left ventricle dysfunction post-MI and increases vasoactive peptides expression and nitric oxide (NO) generation.

Efficacy of pre-exercise low-level laser therapy on isokinetic muscle performance in individuals with type 2 diabetes mellitus: study protocol for a randomized controlled trial.

BACKGROUND: Type 2 diabetes, also known non-insulin-dependent diabetes, is the most prevalent type of the disease and involves defects in the secretion and action of insulin. The aim of the proposed study is to evaluate the efficacy of pre-exercise low-level laser therapy (LLLT) on muscle performance of the quadriceps femoris in individuals with type 2 diabetes. METHODS/DESIGN: A double-blind, randomized, controlled clinical trial will be carried out in two treatment phases. In the first phase, quadriceps muscle performance will be evaluated using an isokinetic dynamometer and the levels of creatine kinase and lactate dehydrogenase (biochemical markers of muscle damage) will be determined. The participants will then be allocated to four LLLT groups through a randomization process using opaque envelopes: Group A (4 Joules), Group B (6 Joules), Group C (8 Joules) and Group D (0 Joules; placebo). Following the administration of LLLT, the participants will be submitted to an isokinetic eccentric muscle fatigue protocol involving the quadriceps muscle bilaterally. Muscle performance and biochemical markers of muscle damage will be evaluated again immediately after as well as 24 and 48 hours after the experimental protocol. One week after the last evaluation the second phase will begin, during which Groups A, B and C will receive the LLLT protocol that achieved the best muscle performance in phase 1 for a period of 4 weeks. At the end of this period, muscle performance will be evaluated again. The protocol for this study is registered with the World Health Organization under Universal Trial Number U1111-1146-7109. DISCUSSION: The purpose of this randomized clinical trial is to evaluate the efficacy of pre-exercise LLLT on the performance of the quadriceps muscle (peak torque, total muscle work, maximum power and fatigue index - normalized by body mass) in individuals with DM-2. The study will support the practice of evidence-based to the use of LLLT in improving muscle performance in Individuals with DM-2. Data will be published after the study is completed.

Effect of low-level laser therapy (660 nm) on acute inflammation induced by tenotomy of Achilles tendon in rats.

In this study, we aimed to analyze the effects of low-level laser therapy (LLLT; 660 nm) on levels of protein expression of inflammatory mediators after cutting Achilles tendon of rats. Thirty Wistar male rats underwent partial incisions of the left Achilles tendon, and were divided into three groups of 10 animals according to the time of euthanasia after injury: 6, 24 and 72 h. Each group was then divided into control group and LLLT group (treated with 100 mW, 3.57 W cm(-2), 0.028 cm(2), 214 J cm(-2), 6 J, 60 s, single point). In LLLT group, animals were treated once time per day until the time of euthanasia established for each group. The group treated with LLLT showed a significant reduction of IL-1ß compared with control groups at three time points (6 h: P=0.0401; 24 h: P=0.0015; 72 h: P=0.0463). The analysis of IL-6 showed significant reduction only in the LLLT group at 72 h compared with control group (P=0.0179), whereas IL-10 showed a significant increase in the treated group compared with control group at three experimental times (6 h: P=0.0007; 24 h: P=0.0256; 72 h: P<0.0001). We conclude that LLLT is an important modulator of inflammatory cytokines release after injury in Achilles tendon.