The effect of low-power laser on red, infrared wavelengths and their associations in inflammation and classification of oral mucositis induced by 5-FU in hamsters

• Grant number: 19/03412-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2019
• End date: March 31, 2020
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Alyne Simões Gonçalves
• Grantee: Bianca Kaori Yshikawa
• Host Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The benefits of low-power photobiostimulation (PBM) are already well known for prevention or treatment of oral mucositis (OM), an inflammatory condition of the oral mucosa caused by conventional chemotherapy and head and neck radiotherapy. Therefore, several options for the application of laser have appeared on the market, such as the simultaneous application of red (660nm) and infrared (830nm) wavelengths. However, there isn't scientific evidence regarding the effect of this simultaneous application on OM. Thus, this study aims to compare the simultaneous application of 660 nm and 830 nm wavelengths with isolated applications of each of those wavelengths in the repair of OM, following the protocols that have already demonstrated efficacy in the literature for treatment of that lesion. In order of that, 40 male syrian hamsters weighing approximately 150g will be used. The animals will be divided into 4 groups: Chemotherapy (L0), which will receive the OM induction protocol (5-FU chemotherapy and slots); Red laser (RL) that will receive induction of OM and low power laser protocol of 660 nm, with 10J/cm2 and 0.3J at a central point; Infrared laser (IRL), which in addition to the induction of OM will receive protocol of 10J/cm2 and 0.3J at a central point; And the group of simultaneous application of the wavelengths 660nm and 830nm, with 10J/cm2 and 0,3J. The equipment will be the Therapy XT, DMC, with 100mW of power and spot area of 0.028cm2. The oral lesions will be evaluated by a subjective scale and measured by a calibrated operator. The animals will be euthanized after 7 and 10 days of experiment, and the oral mucosa will be removed for histological analyses (light microscopy and collagen marking by the technique of Mallory's Trichrome), immunohistochemistry (TNF-±) and biochemical analyses (TNF-± and hydroxyproline).

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COTOMACIO, CLAUDIA C.; YSHIKAWA, BIANCA K.; CALARGA, CAIO C.; ARANA-CHAVEZ, VICTOR E.; SIMOES, ALYNE. Red, infrared, and simultaneous laser-wavelengths irradiation effects on 5-fluorouracil-induced oral mucositis in hamsters. Journal of Biophotonics, v. N/A, p. 9-pg., 2023-07-14. (19/03412-4)