The mitochondrial-related effect of the 905 nm photobiomodulation therapy on 50B11 sensory neurons

Photobiomodulation therapy (PBMT) is known as a complementary tool to alleviate pain sensation in patients, nevertheless, there is still a gap of knowledge on its mechanism of action, thus limiting its clinical employment. In this study, a possible molecular mechanism of the 905 nm PBMT (0.25 W/cm(2); 3, 6, 12, and 18 J/cm(2), 5 Hz) analgesic effect was tested on 50B11 cells, by investigating its impact on mitochondria. A decrement of adenosine triphosphate was detected, moreover, an increment of total reactive oxygen species and mitochondrial superoxide anion was found after PBMT with all protocols tested. PBMT at 18 J diminished the mitochondrial membrane potential, and influenced mitochondrial respiration, decreasing the oxygen consumption rate. Finally, a decrement of extracellular signal-regulated kinase 1/2 phosphorylation was observed with the protocol using 12 J. Taken together these findings highlighted the intracellular effects, mainly correlated to mitochondrial, induced by 905 nm PBMT in sensory neurons, indicating the central role of this organelle in the cellular response to 905 nm near-infrared laser light.