Influence of different photobiomodulation therapy protocols, in the red wavelength range, upon the modulation of the inflammatory process and repair of oral lesions, induced by 5-FU, in hamsters

Abstract

Oral mucositis (OM) is one of the most debilitating side effects of cancer treatment and can be responsible for treatment interruption, increasing patient's morbidity and mortality. The 5-Fluorouracil (5-FU) is an antimetabolic chemotherapy that inhibits cellular mitosis, causing OM. One therapy that has been widely used for the treatment of these lesions is the Photobiomodulation Therapy (PBMT), however there is no consensus in the literature about the best irradiation protocol for oral mucosa wound healing. Therefore, the aim of this study is to analyze the wound healing process of OM treated with different PBMT protocols. For this proposal, 60 hamsters will be used. The animals will be divided into five groups: "C", which will just receive anestesia and chemotherapeutic vehicle; "Ch" which will receive anesthesia and OM induction by 5-FU injection and oral mucosa superficial scratching; "ChL1" the same as CQ group +PBMT 6 J/cm²/0,24J; "ChL2", the same as CQ group +PBMT 25J/cm²/0,1 J; "ChL3" the same as CQ group +PBMT 6 J/cm²/1,2 J . The laser equipment has »=660 nm and 0.04 cm² of spot area. Oral lesions will be assessed on 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 (light microscopy - hematoxylin and eosin stain), immunohistochemical (TNF-±) and biochemical (TNF-±) analysis.