Effects of photobiomodulation on interleukin-10 and nitrites in individuals with relapsing-remitting multiple sclerosis - Randomized clinical trial.

OBJECTIVE: Investigate the effects of photobiomodulation (PBM) on the expression of IL-10 and nitrites in individuals with Relapsing-Remitting multiple sclerosis (MS), as these biomarkers play a fundamental role in the physiopathology of the disease. The modulation of IL-10 and nitrites through treatment with PBM may be a novel treatment modality for MS. METHODS: A randomized, uncontrolled, clinical trial was conducted involving 14 individuals with a diagnosis of Relapsing-Remitting MS and a score of up to 6.0 on the Expanded Disability Status Scale (EDSS). THE PARTICIPANTS WERE RANDOMIZED TO TWO GROUPS: Group 1 -PBM in the sublingual region; Group 2 -PBM over the radial artery. Irradiation was administered with a wavelength of 808 nm and output power of 100 mW for 360 seconds twice a week, totaling 24 sessions. Peripheral blood was analyzed for the determination of serum levels of IL-10 and nitrites. RESULTS: After treatment with PBM, the expression of IL-10 increased in both the sublingual group (pre-treatment: 2.8 ± 1.4 pg/ml; post-treatment: 8.3 ± 2.4 pg/ml) and the radial artery group (pre-treatment: 2.7 pg/ml ± 1.4; post-treatment: 11.7 ± 3.8 pg/ml). In contrast, nitrite levels were not modulated in the sublingual group (pre-treatment: 65 ± 50 nmol/mg protein; post-treatment: 51 ± 42 nmol/mg protein) or the radial artery group (pre-treatment: 51 ± 16 nmol/mg protein; post-treatment: 42 ± 7 nmol/mg protein). CONCLUSION: Treatment with PBM positively modulated the expression of IL-10 but had no effect on nitrite levels. Further studies should be conducted with a larger sample and a control group, as PBM may be a promising complementary treatment for the management of MS. This trial is registered at ClinicalTrials.gov. Identifier: NCT03360487.

Acute Effects Using Light-Emitting Diode Therapy (LEDT) for Muscle Function during Isometric Exercise in Asthma Patients: A Pilot Study.

The aim of this study was to evaluate the effectiveness of acute application of LEDT in improving peripheral muscle performance during isometric exercise in patients with asthma. Eleven patients, with a mean age 38 ± 10, underwent a single LEDT and sham application in the femoral quadriceps' dominant member (cluster with 50 LED λ = 850 nm, 50 mW, 15 s; 37.5 J), 48 h apart in a randomized crossover design. Before and after LEDT and sham application, the patients were submitted an isometric endurance test (60% of the maximum isometric voluntary contraction), up to the limit of tolerance simultaneous recording of surface electromyography. There were no statistically significant differences between groups at the time of contraction (before 41±14 versus 44±16; after 46±12 versus 45±20 s) during the isometric contraction test and inflammatory markers before and after a single LEDT application. A single application of LEDT in the parameters and dose according to the equipment used in the study were not able to promote differences in the time of contraction and the fatigue response in asthmatic patients. However, the chronic effects of LEDT application for improving muscle performance in these patients are unknown and may present different responses during applications for a long time.

Photobiomodulation Leads to Reduced Oxidative Stress in Rats Submitted to High-Intensity Resistive Exercise.

The aim of this study was to determine whether oxidative stress markers are influenced by low-intensity laser therapy (LLLT) in rats subjected to a high-intensity resistive exercise session (RE). Female Wistar rats divided into three experimental groups (Ctr: control, 4J: LLLT, and RE) and subdivided based on the sampling times (instantly or 24 h postexercise) underwent irradiation with LLLT using three-point transcutaneous method on the hind legs, which was applied to the gastrocnemius muscle at the distal, medial, and proximal points. Laser (4J) or placebo (device off) were carried out 60 sec prior to RE that consisted of four climbs bearing the maximum load with a 2 min time interval between each climb. Lipoperoxidation levels and antioxidant capacity were obtained in muscle. Lipoperoxidation levels were increased (4-HNE and CL markers) instantly post-RE. LLLT prior to RE avoided the increase of the lipid peroxidation levels. Similar results were also notified for oxidation protein assays. The GPx and FRAP activities did not reduce instantly or 24 h after RE. SOD increased 24 h after RE, while CAT activity did not change with RE or LLLT. In conclusion, LLLT prior to RE reduced the oxidative stress markers, as well as, avoided reduction, and still increased the antioxidant capacity.

Red and Infrared Low-Level Laser Therapy Prior to Injury with or without Administration after Injury Modulate Oxidative Stress during the Muscle Repair Process.

INTRODUCTION: Muscle injury is common among athletes and amateur practitioners of sports. Following an injury, the production of reactive oxygen species (ROS) occurs, which can harm healthy muscle fibers (secondary damage) and delay the repair process. Low-level laser therapy (LLLT) administered prior to or following an injury has demonstrated positive and protective effects on muscle repair, but the combination of both administration times together has not been clarified. AIM: To evaluate the effect of LLLT (660 nm and 780 nm, 10 J/cm², 40 mW, 3.2 J) prior to injury with or without the administration after injury on oxidative stress during the muscle repair process. METHODS: Wistar rats were divided into following groups: control; muscle injury alone; LLLT 660 nm + injury; LLLT 780 nm + injury; LLLT 660 nm before and after injury; and LLLT 780 nm before and after injury. The rats were euthanized on days 1, 3 and 7 following cryoinjury of the tibialis anterior (TA) muscle, which was then removed for analysis. RESULTS: Lipid peroxidation decreased in the 660+injury group after one day. Moreover, red and infrared LLLT employed at both administration times induced a decrease in lipid peroxidation after seven days. CAT activity was altered by LLLT in all periods evaluated, with a decrease after one day in the 780+injury+780 group and after seven days in the 780+injury group as well as an increase in the 780+injury and 780+injury+780 groups after three days. Furthermore, increases in GPx and SOD activity were found after seven days in the 780+injury+780 group. CONCLUSION: The administration of red and infrared laser therapy at different times positively modulates the activity of antioxidant enzymes and reduces stress markers during the muscle repair process.

Hemodynamic effect of laser therapy in spontaneously hypertensive rats.

Systemic arterial hypertension (SAH) is considered to be the greatest risk factor for the development of neuro-cardiovascular pathologies, thus constituting a severe Public Health issue in the world. The Low-Level Laser Therapy (LLLT), or laser therapy, activates components of the cellular structure, therefore converting luminous energy into photochemical energy and leading to biophysical and biochemical reactions in the mitochondrial respiratory chain. The LLLT promotes cellular and tissue photobiomodulation by means of changes in metabolism, leading to molecular, cellular and systemic changes. The objective of this study was to analyze the action of low-level laser in the hemodynamic modulation of spontaneously hypertensive rats, in the long term. Animals (n = 16) were randomly divided into the Laser Group (n = 8), which received three weekly LLLT irradiations for seven weeks, and into the Sham Group (n = 8), which received three weekly simulations of laser for seven weeks, accounting for 21 applications in each group. After seven weeks, animals were cannulated by the implantation of a catheter in the left carotid artery. On the following day, the systemic arterial pressure was recorded. The Laser Group showed reduced levels of mean blood pressure, with statistically significant reduction (169 ± 4 mmHg* vs. 182 ± 4 mmHg from the Sham Group) and reduced levels of diastolic pressure (143 ± 4 mmHg* vs. 157 ± 3 mmHg from the Sham Group), revealing a 13 and 14 mmHg decrease, respectively. Besides, there was a concomitant important decline in heart rate (312 ± 14 bpm vs. 361 ± 13 bpm from the Sham Group). Therefore, laser therapy was able to produce hemodynamic changes, thus reducing pressure levels in spontaneously hypertensive rats.

Autonomic changes in young smokers: acute effects of inspiratory exercise.

PURPOSE: One of the most important consequences of smoking is the development of cardiovascular diseases. However, little is known about the early consequences of smoking and the acute effects of a single inspiratory muscle exercise session (IME). We evaluated the acute effects of an IME on cardiac parameters of young smokers. METHODS: Twelve nonsmokers (C) and fifteen smokers [S; 2.08 (1.0-3.2) pack-years] underwent an acute IME. We evaluated blood pressure (BP) and lactate, and we recorded RR interval for posterior analysis of heart rate variability (HRV), before and after IME. RESULTS: At baseline, systolic BP and HRV parameters in time and frequency domains were changed in S group in comparison with the C. Following IME, S group reduced systolic BP (-8 %), low frequency band (LF) (-21.4 %), LF/high frequency (HF) (-57 %), as well as increased RR variance (+105 %) and HF band. CONCLUSIONS: Our findings indicate that a single session of inspiratory muscle exercise was able to both reduce systolic BP and improve parasympathetic and sympathetic modulations in young smokers. The results of the current study highlight the importance of furthering research on this area to better elucidate the acute and chronic effects of inspiratory muscle training on early cardiovascular and pulmonary changes of cigarette smoking.