Analysis of the Effect of Phototherapy on the Inflammatory Mediators in an Experimental Model of Ischemic Vascular Accident

Abstract

Cerebral Vascular Accident (CVA) is a sudden neurological condition, which mostly results from cerebral ischemia. Responsible for a large number of deaths and functional disability worldwide, it is extremely important to implement preventive strategies and identify new therapies. Phototherapy has been an excellent therapeutic modality for several diseases, few studies have explored this therapeutic modality for the treatment of stroke. The aim of this study was to analyze whether the treatment with LLLT is able to modulate the inflammatory mediators in the experimental model of ischemic stroke (AVCI). The study was approved by the Ethics Committee on Animal Use of the Federal University of São Paulo (CEUA / UNIFESP) under the number 3316110516. The investigation was conducted in conformance with the FASEB Statement of Principles for the use of Animals in Research and Education. The AVC was induced by the photothrombosis method in 8 male Wistar rats (230 ± 20g) randomly assigned to two experimental groups: Group AVC Control (AVCC) and Group AVC Laserterapia (AVCL). The application of transcranial LLLT was done using a laser diode (MM Optics), with wavelength of 780 ± 5nm, power density of 10 mW / cm2, for 2 minutes, 3× / week for a period of 2 months . The animals were euthanized with anesthetic overdoses of Barbituric / Thiopental Sodium (Cristália) at a dose of 80 mg / kg intraperitoneally; transcardiac perfusion was performed and then the biological tissue (brain) was extracted. The tissues were frozen in liquid nitrogen. The levels of TNF‐α, IL‐1β, IL‐6, IL‐10, VEGFA, BDNF, IGF1, TGFB1 and ANGIOTENSIN II in the samples were determined by the enzyme‐linked immunosorbent assay (ELISA), following commercial kit instructions (R & D System, USA). ). Data were analyzed by the Shapiro‐Wilk normality test in order to verify that the samples come from populations with normal distribution; then the variance test was performed using the Snedecor F test, and then the unpaired T‐test was used; for all tests was considered α = 5%. Our results indicate that there was modulation of the IL1‐b mediators (AVCC 0.4075 ± 0.156659 × AVCL 0.232091 ± 0.083417 p <0.01); IL‐6 (AVCC 180.5753 ± 49.70076 × AVCL 25.47956 ± 15.58209; p <0.001); TNF (40.06277 ± 17.23243 × AVCL 18.2546 ± 5.8065; p <0.01), and in relation to IL‐10 and TGF‐β there were no significant changes. We can conclude that phototherapy modulates the inflammatory response , This result may indicate that the area of shadow of the lesion could be smaller favoring recovery after AVC.Support or Funding InformationFinancial Support: Foundation for Research Support of the State of São Paulo (FAPESP) 2016 / 10286‐7This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.