EFFECTS OF LOCAL, SYSTEMIC, AND COMBINED PHOTOBIOMODULATION THERAPY ON METABOLIC PARAMETERS IN STREPTOZOTOCIN-INDUCED DIABETES IN MICE

Photobiomodulation therapy (PBM) has emerged as a promising non-invasive therapeutic strategy that can be applied systemically and/or locally to treat chronic diseases. This study investigated the impact of local, systemic, and combined PBM protocols in a murine model of type 1 diabetes mellitus (DM). Male C57BL/6 mice were made diabetic by streptozotocin administration and subsequently treated with PBM applied to the quadriceps femoris, sublingual region, or both. Outcomes included fasting glycemia, body mass, intraperitoneal glucose tolerance test (ipGTT), and daily water intake. PBM showed beneficial effects on basal metabolic outcomes. Localized quadriceps irradiation and combined PBM were associated with better preservation of body mass, lower cumulative fasting glycemic burden, and reduced polydipsia compared with untreated diabetic controls. However, PBM did not restore dynamic glucose homeostasis during ipGTT, indicating that the intervention was insufficient to reverse the severe insulin deficiency characteristic of the streptozotocin model. Overall, the findings suggest that PBM, under the present experimental conditions, was metabolically safe and capable of attenuating some chronic diabetic manifestations. These results support the potential of PBM as an adjunctive modality in DM management, while highlighting the need for further studies to optimize irradiation parameters, treatment routes, and biological targets.

This work was supported by the National Commission of Nuclear Energy, INCT of Radiation Technologies in Health (INTERAS, CNPq.# 406761/2022-1), and by the São Paulo Research Foundation (FAPESP # 2023/01276-1).