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

Author(s)

Assis, Livia ^[1] ; Moretti, Ana I. S. ^{[2, 3]} ; Abrahao, Thalita B. ^[4] ; Cury, Vivian ^[1] ; Souza, Heraldo P. ; Hamblin, Michael R. ^{[5, 6, 7]} ; Parizotto, Nivaldo A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Phisiotherapy, Lab Electrothermophototherapy, Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Fac Med, Emergency Med Div, Lab Med Res, BR-01246903 Sao Paulo - Brazil

^[3] Inst Assistencia Med Servidor Publ Estadual IAMSP, Postgrad Hlth Sci Program, Sao Paulo - Brazil

^[4] Univ Sao Paulo, Fac Med, Lab Vasc Biol, Dept Cardiopneumol, Heart Inst, BR-01246903 Sao Paulo - Brazil

^[5] Harvard Univ, Sch Med, Dept Dermatol, Boston, MA 02115 - USA

^[6] Harvard MIT Div Hlth Sci & Technol, Cambridge, MA - USA

^[7] Massachusetts Gen Hosp, Wellman Labs Photomed, Boston, MA 02114 - USA

• Document type: Journal article
• Source: Lasers in Surgery and Medicine; v. 44, n. 9, p. 726-735, NOV 2012.
• Web of Science Citations: 64

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-k beta and COX-2 and by TNF-a and IL-1 beta 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: 726735, 2012. (c) 2012 Wiley Periodicals, Inc. (AU)

• FAPESP's process: 09/01990-9 - Nuclear Receptors and Transcription Coactivators in Inflammatory Diseases
• Grantee: Heraldo Possolo de Souza
• Support Opportunities: Regular Research Grants