Photobiomodulation enhances mitochondrial respiration in an in vitro rotenone model of Parkinson's disease

Photobiomodulation (PBM) using nonionizing light sources, including lasers, light-emitting diodes, and/or broadband light, in the visible (400 to 700 nm) and near-infrared (700 to 1100 nm) electromagnetic spectrum, has been successfully exploited for multiple therapeutic purposes. We analyzed the effects of red and infrared irradiation on neuroblastoma cells in an in vitro rotenone model of Parkinson's disease. Cell viability was assessed by colorimetric assay for metabolic activity (MTT test), and the oxygen consumption rate was analyzed using a Seahorse analyzer. Low doses of rotenone slightly, but not significantly, suppressed oxygen consumption and did not affect cell viability within 2 hours of treatment. PBM stimulated mitochondrial respiration overcoming rotenone-induced inhibition. At high doses (50 μM), rotenone moderately suppressed cell viability, which was reversed by PBM. Thus, preliminary treatment with red and infrared radiation improves cell viability and enhances mitochondrial oxygen consumption in an in vitro rotenone model of Parkinson's disease.