Efeito da terapia com fotobiomodulação sobre a inflamação pulmonar em modelo experimental de asma crônica

Abstract

Asthma affects a significant portion of the population, with a high social and economic cost. Photobiomodulation therapy (FBM) is a treatment that demonstrates efficacy in lung diseases by reducing inflammatory symptoms, with low cost and without side effects. The objective was to evaluate the effects of FBM therapy in an experimental model of chronic lung inflammation induced by ovalbumin (OVA). Balb/C mice were divided into 6 groups: Control, OVA, and OVA+FBM (OVA+1J, OVA+3J, OVA+5J, OVA+7.5J). Inflammation was induced by OVA sensitization (day 0 and day 14) and orotracheal challenge from day 21 (3 days/week for 5 weeks). One hour after the challenge, irradiation with a diode laser (660nm, 100mW) was applied, using different irradiation times (10s, 30s, 50s and 75s), at three different points, one below the trachea and one in each lung lobe. Twenty-four hours after the last treatment, the animals were anesthetized and euthanized for collection of bronchoalveolar lavage (BAL) and lungs. Parameters such as total and differential cell counts, BAL cytokine levels, mucus production, collagen deposition, quantification of macrophages, neutrophils, eosinophils in the lung, as well as analyzing the rate of T lymphocytes (CD4 and CD25) and T controllers ( Foxp3) and IL-10 release by cell assays. The data were left to the One-way ANOVA test followed by the Newman-Keuls post-test. Significance levels adjusted to 5% (p<0.05). Therapy with FBM was able to reduce the pulmonary inflammation observed by reducing the total and differential number of cells in the BAL, mainly with regard to the number of eosinophils, in addition we verified the decrease in the levels of the pro-inflammation cytokines IL-4, IL- 5 and IL-13 in BAL in the group treated with FBM, as well as the increase in IL-10 levels. for the values of CD4+IL-10+ lymphocytes we witnessed an increase in all groups treated with FBM. These results revealed that FBM therapy had a beneficial effect on cell migration to the lung, as well as the stimulation of IL-10 production. We also noticed a reduction in the deposition of mucus and collagen in the airways in the groups submitted to FBM therapy with the energies of 3J and 5J. Therefore, we conclude that the use of FBM therapy in chronic airway inflammation attenuated the inflammatory process, as well as related functional and pulmonary parameters, probably due to the increase in regulatory T cells.