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

Author(s)

Trawitzki, Bianca F. ^{[1, 2, 3]} ; Lilge, Lothar ^{[1, 2]} ; de Figueiredo, Fellipe A. T. ^[3] ; Macedoa, Ana Paula ^[3] ; Issa, Joao Paulo M. ^{[1, 2, 3]}

Affiliation

^[1] Princess Margaret Canc Ctr, Univ Hlth Network, 101 Coll St, Toronto, ON - Canada

^[2] Univ Toronto, Dept Med Biophys, 101 Coll St, Toronto, ON - Canada

^[3] Univ Sao Paulo, Sch Dent Ribeirao Preto, Ave Cafe S-N, Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY; v. 174, p. 126-132, SEP 2017.
• Web of Science Citations: 2

Abstract

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 24 h 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 660 nm (S = 18.5 (11.4; 27.6); D = 16.0 (6.93; 27.0)) and high intensity and pulsed 905 nm (S = 17.5 (10.2; 24.79), with decrease of the resorbed region. However, the 905 nm 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 < 0.05). LILT showed signs of an anti-inflammatory effect when applied once, but promoted increased resorptive area when used for two sessions, indicating the importance of a controlled LILT protocol to reach therapeutic effects. (AU)

• FAPESP's process: 12/24264-4 - Evaluation of the efficacy of low level laser therapy in animals submitted to acute arthritis condition
• Grantee: João Paulo Mardegan Issa
• Support Opportunities: Scholarships abroad - Research
• FAPESP's process: 14/16544-2 - Efficacy of low level laser therapy in animals of NFkappa beta strain subjected to the acute arthritis condition
• Grantee: Bianca Ferreira Trawitzki
• Support Opportunities: Scholarships in Brazil - Scientific Initiation