Photobiomodulation Improves Kidney Function and Attenuates Oxidative Stress and Inflammation in a Male Wistar Rat Model of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is characterized by progressive renal dysfunction driven by oxidative stress, inflammation, and hemodynamic alterations. Photobiomodulation (PBM) has emerged as a potential non-invasive therapeutic strategy targeting these pathways. To evaluate the effects of PBM on kidney function, hemodynamics, oxidative stress, and inflammatory profile in a rat model of DKD. Adult male Wistar rats were randomly assigned to four groups: control (Ct), Ct + PBM, DKD, and DKD + PBM. Diabetes was induced by streptozotocin (60 mg/kg, i.v.). PBM (808 nm, 100 mW) was applied transcutaneously (3 J per point; 30.48 J/cm2), bilaterally over the renal region, three times per week for six weeks. Kidney function (inulin clearance, serum creatinine, albuminuria), hemodynamics (mean arterial pressure, renal blood flow, renal vascular resistance), oxidative stress markers (urinary H2O2, NOx, thiols, Nrf2), and IL-1β levels were evaluated. DKD animals showed impaired kidney function, increased oxidative stress, and elevated inflammatory markers. PBM treatment significantly improved inulin clearance, reduced albuminuria and serum creatinine, increased renal blood flow, and decreased mean arterial pressure and vascular resistance. Oxidative stress markers and IL-1β levels were attenuated, with partial restoration of antioxidant capacity. No significant histological differences were observed. PBM improves kidney function and modulates redox and inflammatory pathways in experimental DKD, supporting its potential as a non-invasive adjunct therapy.