Low-intensity laser therapy efficacy evaluation in mice subjected to acute arthritis condition

• Published in: Journal of photochemistry and photobiology. B, Biology Biology, 2017-09, Vol.174, p.126-132
• Main Authors: Trawitzki, Bianca F., Lilge, Lothar, de Figueiredo, Fellipe A.T., Macedo, Ana Paula, Issa, João Paulo M.
• Format: Article
• Language: English
• Subjects: Acute Disease; Animal models; Animals; Arthritis; Arthritis - chemically induced; Arthritis - metabolism; Arthritis - pathology; Arthritis - radiotherapy; Confidence intervals; Corticoids; Corticosteroids; Drugs; Histology; Immunohistochemistry; Inflammation; Inflammatory response; Joint diseases; Knee; Lasers; LILT; Lipopolysaccharides - pharmacology; Low-Level Light Therapy; Male; Medical treatment; Mice; Null hypothesis; Osteocalcin - metabolism; Osteoprotegerin - metabolism; RANK Ligand - metabolism; Repair; Statistical analysis; Studies; Surgery; Tartrate-Resistant Acid Phosphatase - metabolism; Therapy; Wavelengths
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2017.07.028

Acute arthritis is an inflammation that affects many joints. The principal treatment options comprise drugs (corticosteroids), invasive and painful surgery. The objective of this study was to evaluate the efficacy of low intensity laser therapy (LILT), a non-invasive treatment, in a murine model of acute inflammation model. 48 mice received a synovial injection of Zymosan A into one knee. Mice were treated with LILT by three different wavelengths, either as a single (S) or dual (D) application immediately after the injury or after 24h following initiation of an inflammatory response. The histological analysis aimed at identifying inflammatory infiltrate and the structure of the articular surfaces as an indicator of a long-term damage due to inflammation. Statistical analysis (Kruskal-Wallis test), did not allow to reject the null hypothesis. However, LILT promoted histological alterations in some treatment groups. Histological evidence (Median and confidence interval) of anti-inflammatory effects was especially noticeable in knees of mice irradiated with lasers emitting moderate intensity and continuous 660nm (S=18.5 (11.4; 27.6); D=16.0 (6.93; 27.0)) and high intensity and pulsed 905nm (S=17.5 (10.2; 24.79), with decrease of the resorbed region. However, the 905nm pulsed laser was responsible for exacerbation of inflammation for multiple LILT sessions with a short delay (D=45.0 (22.84; 63.83)), tending to aggravate the resorption of the articular surface (p