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Low-level laser therapy (808 nm) reduces inflammatory response and oxidative stress in rat tibialis anterior muscle after cryolesion

Authors

  • Lívia Assis MS, PhD,

    1. Laboratory of Electrothermophototherapy, Department of Phisiotherapy, University of São Carlos, São Carlos, SP, Brazil
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  • Ana I.S. Moretti MS, PhD,

    Corresponding author
    1. Emergency Medicine Division, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
    2. Post-Graduate Health Sciences Program, Instituto de Assistência Médica ao Servidor Público Estadual—IAMSPE, São Paulo, SP, Brazil
    • Laboratory of Medical Research, Emergency Medicine Division, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil Av. Dr. Arnaldo, 455 sala 3189, 01246-903 São Paulo, SP, Brazil.
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  • Thalita B. Abrahão PhD,

    1. Laboratory of Vascular Biology, Department of Cardiopneumology, Heart Institute, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
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  • Vivian Cury MS,

    1. Laboratory of Electrothermophototherapy, Department of Phisiotherapy, University of São Carlos, São Carlos, SP, Brazil
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  • Heraldo P. Souza MD, PhD,

    1. Emergency Medicine Division, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil
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  • Michael R. Hamblin PhD,

    1. Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
    2. Department of Dermatology, Harvard Medical School, Boston, Massachusetts
    3. Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts
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  • Nivaldo A. Parizotto MS, PhD

    1. Laboratory of Electrothermophototherapy, Department of Phisiotherapy, University of São Carlos, São Carlos, SP, Brazil
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  • Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.

Abstract

Background and Objective

Muscle regeneration is a complex phenomenon, involving coordinated activation of several cellular responses. During this process, oxidative stress and consequent tissue damage occur with a severity that may depend on the intensity and duration of the inflammatory response. Among the therapeutic approaches to attenuate inflammation and increase tissue repair, low-level laser therapy (LLLT) may be a safe and effective clinical procedure. The aim of this study was to evaluate the effects of LLLT on oxidative/nitrative stress and inflammatory mediators produced during a cryolesion of the tibialis anterior (TA) muscle in rats.

Material and Methods

Sixty Wistar rats were randomly divided into three groups (n = 20): control (BC), injured TA muscle without LLLT (IC), injured TA muscle submitted to LLLT (IRI). The injured region was irradiated daily for 4 consecutive days, starting immediately after the lesion using a AlGaAs laser (continuous wave, 808 nm, tip area of 0.00785 cm2, power 30 mW, application time 47 seconds, fluence 180 J/cm2; 3.8 mW/cm2; and total energy 1.4 J). The animals were sacrificed on the fourth day after injury.

Results

LLLT reduced oxidative and nitrative stress in injured muscle, decreased lipid peroxidation, nitrotyrosine formation and NO production, probably due to reduction in iNOS protein expression. Moreover, LLLT increased SOD gene expression, and decreased the inflammatory response as measured by gene expression of NF-kβ and COX-2 and by TNF-α and IL-1β concentration.

Conclusion

These results suggest that LLLT could be an effective therapeutic approach to modulate oxidative and nitrative stress and to reduce inflammation in injured muscle. Lasers Surg. Med. 44: 726–735, 2012. © 2012 Wiley Periodicals, Inc.

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