The Effect of Red-to-Near-Infrared (R/NIR) Irradiation on Inflammatory Processes

AbstractIntroduction: Near-infrared (NIR) and red-to-near-infrared (R/NIR) radiation are increasingly applied for therapeutic use. R/NIR-employing therapies aim to stimulate healing, prevent tissue necrosis, increase mitochondrial function, and improve blood flow and tissue oxygenation. The wide range of applications of this radiation raises questions concerning the effects of R/NIR on the immune system.Methods: In this review, we discuss the potential effects of exposure to R/NIR light on immune cells in the context of physical parameters of light.Discussion: The effects that R/NIR may induce in immune cells typically involve the production of reactive oxygen species (ROS), nitrogen oxide (NO) or interleukins. Production of ROS after exposure to R/NIR can either be inhibited or to some extent increased, which suggests that detailed conditions of experiments. However, a wide range of immune cell studies have demonstrated that exposure to R/NIR most often has an anti-inflammatory effect.Conclusions: Optimi...