Comparative analysis of two low-level laser doses on the expression of inflammatory mediators and on neutrophils and macrophages in acute joint inflammation

• Published in: Lasers in medical science 2014-05, Vol.29 (3), p.1051-1058
• Main Authors: dos Santos, Solange Almeida, Alves, Ana Carolina Araruna, Leal-Junior, Ernesto Cesar Pinto, Albertini, Regiane, Vieira, Rodolfo de Paula, Ligeiro, Ana Paula, Junior, Jose Antonio Silva, de Carvalho, Paulo de Tarso Camillo
• Format: Article
• Language: English
• Subjects: Animals; Cartilage, Articular - immunology; Cartilage, Articular - metabolism; Cartilage, Articular - radiation effects; Cytokines - genetics; Cytokines - metabolism; Dentistry; Gene Expression; Inflammation Mediators - metabolism; Inflammatory diseases; Lasers; Lasers, Semiconductor - therapeutic use; Leukocyte Count; Low-Level Light Therapy; Macrophages - immunology; Macrophages - radiation effects; Male; Medicine; Medicine & Public Health; Musculoskeletal diseases; Neutrophils - immunology; Neutrophils - radiation effects; Optical Devices; Optics; Original Article; Osteoarthritis, Knee - immunology; Osteoarthritis, Knee - radiotherapy; Photonics; Quantum Optics; Rats, Wistar; Rodents
• ISSN: 0268-8921; 1435-604X
• DOI: 10.1007/s10103-013-1467-2

Synovial membrane inflammation plays an important role in osteoarthritis (OA) pathophysiology. The synovial tissue of patients with initial OA is characterized by mononuclear cell infiltration and the production of pro-inflammatory cytokines and other mediators of joint injury. The study aims to evaluate the effect of low-level laser therapy (LLLT) at doses of 2 and 4 J on joint inflammation in rats induced by papain through histopathological analysis, differential counts of inflammatory cells; gene expression of IL-1β, IL-6, and IL-10; and TNF-α protein expression. Male Wistar rats (20) were randomly divided (5 animals each) into a negative control group, an inflammation injury positive control group, a 2-J LLLT group subjected to injury and treated with 2 J of LLLT, and a 4-J LLLT group subjected to injury and treated with 4 J of LLLT. The animals were subjected to joint inflammation (4 % papain solution) and treated with LLLT. On the day of euthanasia, articular lavage was collected and centrifuged. The supernatant was analyzed for TNF-α protein expression by ELISA and IL-1β, IL-6, and IL-10 mRNA by RT-PCR. The joint tissue was also examined histologically. ANOVA with Tukey's post hoc test was used for comparisons. All data were expressed as means ± S.D. ( p