Effect of Photobiomodulation Therapy in an Experimental Model of Chronic Obstructive Pulmonary Disease: A Dosimetric Study

This study aimed to evaluate the effects of different dosimetric parameters of photobiomodulation therapy (PBMT) in an experimental model of chronic obstructive pulmonary disease (COPD). C57BL/6 mice were assigned to the following groups: Baseline, COPD, and COPD treated with PBMT at doses of 1 J, 3 J, 5 J, and 7.5 J. Treatment was performed using a diode laser (660 nm, 100 mW) applied for 10 s, 30 s, 50 s, and 120 s, respectively, over 15 consecutive days. COPD was induced by orotracheal instillation of cigarette smoke extract twice weekly for 45 days. Analyses included total cell count, immune cell profiling by flow cytometry, pulmonary infiltration of inflammatory markers, necrosis, apoptosis, and reactive oxygen species (ROS) production. Data were analyzed using one-way ANOVA followed by the Newman–Keuls post hoc test, with statistical significance set at p < 0.05. PBMT significantly reduced inflammatory cell infiltration, with the most pronounced anti-inflammatory effects observed at doses of 1 J and 3 J, highlighting the importance of appropriate dosimetry in optimizing the therapeutic outcomes of PBMT for COPD.