Abstract
PURPOSE: This study aimed to investigate the biochemical and morphological effects of photobiomodulation (PBM) and supplementation with clarified açaí on the submandibular glands in a chemically induced oral mucositis model in rats. Methods: 102 rats were divided into five groups- control: no induction of oral mucositis (OM); untreated group: OM induction, no treatment; PBM: OM induction and laser application (660 nm, 100 mW, 0.24 J, 2.4 s per point, 8 J/cm(2) and in contact only at the OM site, bilaterally); açaí: OM induction and supplementation with clarified açaí; and PBM + açaí: OM induction and combination of the two treatments mentioned above. Oral mucositis was chemically induced by 5-fluorouracil (5-FU) on days 0 (60 mg/kg) and 2 (40 mg/kg). PMB and supplementation with clarified açaí (dose of 1 ml/100 g body weight) were used from day 0 of the experiment until euthanasia. On days 0 (control group), 8, 10, and 14 (intervention groups), submandibular glands were collected for analysis, with the right side used for oxidative biochemical analysis and the left side for histological analysis. A two-way statistical analysis of variance (ANOVA) was performed, followed by Tukey's post-hoc test (p < 0.05). Results: PMB, alone or in combination with clarified açaí, significantly increased antioxidant capacity levels and showed significantly lower levels of lipid peroxidation and nitric oxide metabolites compared to the control group (p < 0.0001). Morphologically, PBM, alone or combined with clarified açaí, maintained parenchyma, stroma, and acinar structures similar to the control group, which was not subjected to OM induction. Conclusion: It was experimentally demonstrated that PBM, when used alone or combined with clarified açaí, resulted in improved antioxidant response, in addition to providing glandular protection against structural damage caused by chemotherapy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10103-026-04876-7.