Reactive Oxygen Species Mediated Generalized Photobiomodulation

Photobiomodulation (PBM) is a modulation of monochromatic light or laser irradiation (LI) on biosystems, which stimulates or inhibits biological functions but does not result in irreducible damage. The PBM of low intensity LI (LIL), ~10 mW/cm
²
, moderate intensity LI (MIL), 10
^2-3
mW/cm
²
, high intensity LI (HIL), ~10 W/cm
²
, and photodynamic effect (PDE) are called LPBM, MPBM, HPBM and PPBM, respectively. All of them are called generalized PBM (GPBM). Intravascular low energy laser therapy is just an intravascular MPBM. MPBM, HPBM and PPBM are mediated by reactive oxygen species (ROS). Their mitogen-activated protein kinase (MAPK) signaling pathways and homeostatic regulation are decided by intracellular ROS level so that they can be used in clinic applications such as microbial killing and cancer therapy.