Low infra red laser light irradiation on cultured neural cells: effects on mitochondria and cell viability after oxidative stress

<p>Abstract</p> <p>Background</p> <p>Considerable interest has been aroused in recent years by the well-known notion that biological systems are sensitive to visible light. With clinical applications of visible radiation in the far-red to near-infrared region of the spectrum in mind, we explored the effect of coherent red light irradiation with extremely low energy transfer on a neural cell line derived from rat pheochromocytoma. We focused on the effect of pulsed light laser irradiation vis-à-vis two distinct biological effects: neurite elongation under NGF stimulus on laminin-collagen substrate and cell viability during oxidative stress.</p> <p>Methods</p> <p>We used a 670 nm laser, with extremely low peak power output (3 mW/cm²) and at an extremely low dose (0.45 mJ/cm²). Neurite elongation was measured over three days in culture. The effect of coherent red light irradiation on cell reaction to oxidative stress was evaluated through live-recording of mitochondria membrane potential (MMP) using JC1 vital dye and laser-confocal microscopy, in the absence (photo bleaching) and in the presence (oxidative stress) of H₂O₂, and by means of the MTT cell viability assay.</p> <p>Results</p> <p>We found that laser irradiation stimulates NGF-induced neurite elongation on a laminin-collagen coated substrate and protects PC12 cells against oxidative stress.</p> <p>Conclusion</p> <p>These data suggest that red light radiation protects the viability of cell culture in case of oxidative stress, as indicated by MMP measurement and MTT assay. It also stimulates neurite outgrowth, and this effect could also have positive implications for axonal protection.</p

Photobiomodulation on the angiogenesis of skin wounds in rats using different light sources

Objective: The aim of this study was to compare the angiogenic effects of laser and light-emitting diode ( LED) illumination on wounds induced in rats, with varied fluence. Background Data: The LED is an alternative light source that accelerates wound healing, and its efficiency concerning the angiogenic effect was compared to low-level laser therapy ( LLLT). Methods: The experimental model consisted of a circular wound inflicted on the quadriceps of 120 rats, using a 15-mm-diameter "punch." Animals were divided randomly into five groups: two groups of laser, with dosages of 5 and 20 J/cm(2), respectively, two groups of LED, also with dosages of 5 and 20 J/cm(2), and a control group. Six hours after wound infliction, the treated groups received the diverse applications accordingly and were irradiated every 24 h. Angiogenesis was studied through histomorphometry on days 3, 7, 14, and 21 after the wounds were inflicted. Results: On days 3, 7, and 14, the proliferation of blood vessels in all irradiated groups was superior in comparison to those of the control group ( p < 0.05). Treatment with fluence of 5 J/cm(2) was better than the laser group with 20 J/cm(2) on day 21. Conclusion: Red LLLT and LED demonstrated expressive results in angiogenesis. Light coherence was shown not to be essential to angiogenesis. However, further studies are needed in order to investigate the photobiomodulatory effects of LED in relation to LLLT in various biological tissues.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.25210210

Phototherapy and resistance training prevent sarcopenia in ovariectomized rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of this study was to histologically and biochemically analyze the effects of light-emitting diode therapy (LEDT) associated with resistance training to prevent sarcopenia in ovariectomized rats. Forty female Wistar rats (12 months old, 295-330 g) were bilaterally ovariectomized and divided into four groups (n = 10 per group): control-sedentary (C), resistance training (T), LEDT-sedentary (L), and LEDT plus resistance training (LT). Trained rats performed a 12-week water-jumping program (3 days per week) carrying a load equivalent to 50-80 % of their body mass strapped to their back. Depending on the group protocol, the LED device (850 nm, 100 mW, 120 J/cm(2), spot size 0.5 cm(2)) was used either as the only method or after the resistance training had been performed. The device was used in the single point contact mode (for 10 min). The irradiated region was the center of the greater trochanter of the right femur and the middle third of the rectus femoris muscle was subsequently analyzed histomorphometrically. Significant increases (p < 0.05) were noted for the muscle volume of the T (68.1 +/- 19.7 %), the L (74.1 +/- 5.1 %), and the LT (68.2 +/- 11.5 %) groups compared to the C group (60.4 +/- 5.5 %). There were also significant increases in the concentrations of IGF-1, IL-1, and TNF-alpha in the muscles of the treated groups (p < 0.05). Animals in the LT group showed a significant increase in IL-6 compared to T, L, and C groups (p < 0.05). These findings suggest that resistance training and LEDT can prevent sarcopenia in ovariectomized rats.28614671474Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Thermography Applied During Exercises With or Without Infrared Light-Emitting Diode Irradiation: Individual and Comparative Analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Objective: The aim of our study was to evaluate the cutaneous temperature during an exercise on a treadmill with or without infrared light-emitting diode (LED) irradiation in postmenopausal women. Background data: Thermography is an imaging technique in which radiation emitted by a body in the middle and far infrared spectrum is detected and associated with the temperature of the body's surface. Materials and methods: Eighteen postmenopausal women were randomly divided into two groups: (1) the LED group, which performed the exercises on a treadmill associated with phototherapy (n = 9) and; (2) the exercise group, which performed the exercises on a treadmill without additional phototherapy (n = 9). The irradiation parameters for each women's thigh were: array of 2000 infrared LEDs (850 nm) with an area of 1,110 cm(2), 100 W, 39 mW/cm(2), and 108 J/cm(2) for 45 min. The submaximal constant-speed exercise on the treadmill at intensities between 85% and 90% maximal heart rate (HRmax) with or without phototherapy were performed during 45 min, to perform the thermographic analysis. Thermography images were captured before the exercise (t = 0), after 10, 35, and 45 min of exercising (t = 10, t = 35, and t = 45) and at 5 min post-exercising (t = 50). Results: The LED group showed an increased cutaneous thigh temperature during the exercise (from 33.5 +/- 0.8 degrees C to 34.6 +/- 0.9 degrees C, p = 0.03), whereas the exercise group showed a reduced cutaneous temperature (from 33.5 +/- 0.6 to 32.7 +/- 0.7 degrees C, p = 0.02). The difference between the groups was significant (p < 0.05) at t = 35, t = 45, and t = 50. Conclusions: These data indicate an improved microcirculation, and can explain one possible mechanism of action of phototherapy associated with physical exercises.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.317349355Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [2008/578588-9, 98/14270-8]CNPq [573587/2008, 151008/2012-4

Infrared LED irradiation applied during high-intensity treadmill training improves maximal exercise tolerance in postmenopausal women: a 6-month longitudinal study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Reduced aerobic fitness is associated with an increased risk of cardiovascular diseases among the older population. The aim of this study was to investigate the effects of LED irradiation (850 nm) applied during treadmill training on the maximal exercise tolerance in postmenopausal women. At the beginning of the study, 45 postmenopausal women were assigned randomly to three groups, and 30 women completed the entire 6 months of the study. The groups were: (1) the LED group (treadmill training associated with phototherapy, n = 10), (2) the exercise group (treadmill training, n = 10), and (3) the sedentary group (neither physical training nor phototherapy, n = 10). The training was performed for 45 min twice a week for 6 months at intensities between 85% and 90% maximal heart rate (HRmax). The irradiation parameters were 39 mW/cm(2), 45 min and 108 J/cm(2). The cardiovascular parameters were measured at baseline and after 6 months. As expected, no significant differences were found in the sedentary group (p a parts per thousand yenaEuro parts per thousand 0.05). The maximal time of tolerance (Tlim), metabolic equivalents (METs) and Bruce stage reached significantly higher values in the LED group and the exercise group (p < 0.01). Furthermore, the HR, double product and Borg score at isotime were significantly lower in the LED group and in the exercise group (p < 0.05). However, the time of recovery showed a significant decrease only in the LED group (p = 0.003). Moreover, the differences between before and after training (delta values) for the Tlim, METs and HR at isotime were greater in the LED group than in the exercise group with a significant intergroup difference (p < 0.05). Therefore, the infrared LED irradiation during treadmill training can improve maximal performance and post-exercise recovery in postmenopausal women.282415422Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [98/14270-8, 09/01842-0]CNPq [150949/2011-1

Phototherapy during treadmill training improves quadriceps performance in postmenopausal women

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Objective To evaluate the effects of infrared-light-emitting diode (LED) during treadmill training on functional performance. Methods Thirty postmenopausal women aged 50-60 years were randomly assigned to one of three groups and successfully completed the full study. The three groups were: (1) the LED group, which performed treadmill training associated with phototherapy (n = 10); (2) the exercise group, which carried out treadmill training only (n = 10); and (3) the sedentary group, which neither performed physical training nor underwent phototherapy (n = 10). Training was performed over a period of 6 months, twice a week for 45 min per session at 85-90% of maximal heart rate, which was obtained during progressive exercise testing. The irradiation parameters were 100 mW, 39 mW/cm(2) and 108 J/cm(2) for 45 min. Quadriceps performance was measured during isokinetic exercise testing at 60 degrees/s and 300 degrees/s. Results Peak torque did not differ amongst the groups. However, the results showed significantly higher values of power and total work for the LED group (Delta= 21 +/- 6 W and Delta = 634 +/- 156 J, p < 0.05) when compared to both the exercise group (Delta = 13 +/- 10 W and Delta = 410 +/- 270 J) and the sedentary group (Delta = 10 +/- 9 W and Delta = 357 +/- 327 J). Fatigue was also significantly lower in the LED group (Delta = -7 +/- 4%, p < 0.05) compared to both the exercise group (Delta = 3 +/- 8%) and the sedentary group (Delta = -2 +/- 6%). Conclusions Infrared-LED during treadmill training may improve quadriceps power and reduce peripheral fatigue in postmenopausal women.173285293Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [98/14270-8, 2008/57858-9, 2009/01842-0]CNPq [573587/2008-6