title: Cell viability, reactive oxygen species, apoptosis, and necrosis in myoblast cultures exposed to low-level infrared laser.
abstract: Low-level infrared laser is considered safe and effective for treatment of muscle injuries. However, the mechanism involved on beneficial effects of laser therapy are not understood. The aim was to evaluate cell viability, reactive oxygen species, apoptosis, and necrosis in myoblast cultures exposed to low-level infrared laser at therapeutic fluences. C2C12 myoblast cultures at different (2 and 10 %) fetal bovine serum (FBS) concentrations were exposed to low-level infrared laser (808 nm, 100 mW) at different fluences (10, 35, and 70 J/cm(2)) and evaluated after 24, 48, and 72 h. Cell viability was evaluated by WST-1 assay; reactive oxygen species (ROS), apoptosis, and necrosis were evaluated by flow cytometry. Cell viability was decreased atthe lowest FBS concentration. Laser exposure increased the cell viability in myoblast cultures at 2 % FBS after 48 and 72 h, but no significant increase in ROS was observed. Apoptosis was decreased at the higher fluence and necrosis was increased at lower fluence in myoblast cultures after 24 h of laser exposure at 2 % FBS. No laser-induced alterations were obtained at 10 % FBS. Results show that level of reactive oxygen species is not altered, at least to those evaluated in this study, but low-level infrared laser exposure affects cell viability, apoptosis, and necrosis in myoblast cultures depending on laser fluence and physiologic conditions of cells.
authors.affiliation: Laboratório de Pesquisa em Células-Tronco, Departamento de Histologia e Embriologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, PAPC, 3° andar, Maracanã, Rio de Janeiro, 20551-170, Brazil.|Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, fundos, Vila Isabel, Rio de Janeiro, 20551-030, Brazil.
authors.forename: Larissa
authors.initials: L
authors.lastname: Alexsandra da Silva Neto Trajano
authors.affiliation: Laboratório de Pesquisa em Células-Tronco, Departamento de Histologia e Embriologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, PAPC, 3° andar, Maracanã, Rio de Janeiro, 20551-170, Brazil.
authors.forename: Camila Luna
authors.initials: CL
authors.lastname: da Silva
authors.affiliation: Laboratório de Pesquisa em Células-Tronco, Departamento de Histologia e Embriologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, PAPC, 3° andar, Maracanã, Rio de Janeiro, 20551-170, Brazil.
authors.forename: Simone Nunes
authors.initials: SN
authors.lastname: de Carvalho
authors.affiliation: Laboratório de Pesquisa em Células-Tronco, Departamento de Histologia e Embriologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, PAPC, 3° andar, Maracanã, Rio de Janeiro, 20551-170, Brazil.
authors.forename: Erika
authors.initials: E
authors.lastname: Cortez
authors.affiliation: Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, fundos, Vila Isabel, Rio de Janeiro, 20551-030, Brazil.
authors.forename: André Luiz
authors.initials: AL
authors.lastname: Mencalha
authors.affiliation: Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida 28 de Setembro, 87, fundos, Vila Isabel, Rio de Janeiro, 20551-030, Brazil. adnfonseca@ig.com.br.|Departamento de Ciências Fisiológicas, Instituto Biomédico, Universidade Federal do Estado do Rio de Janeiro, Rua Frei Caneca, 94, Rio de Janeiro, 20211040, Brazil. adnfonseca@ig.com.br.|Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, Maracanã, Rio de Janeiro, 20550900, Brazil. adnfonseca@ig.com.br.
authors.forename: Adenilson
authors.initials: A
authors.lastname: de Souza da Fonseca
authors.affiliation: Laboratório de Pesquisa em Células-Tronco, Departamento de Histologia e Embriologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Avenida Professor Manuel de Abreu 444, PAPC, 3° andar, Maracanã, Rio de Janeiro, 20551-170, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Stumbo
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects*; D002417:Cattle; D002470:Cell Survival / Q000528:radiation effects*; D028022:Low-Level Light Therapy / Q000379:methods*; D032446:Myoblasts; D009336:Necrosis / Q000532:radiotherapy*; D017382:Reactive Oxygen Species / Q000528:radiation effects*
chemical_list: D017382:Reactive Oxygen Species
keywords: Apoptosis; Cell viability; Low-level laser therapy; Myoblast; Necrosis; Reactive oxygen species