Efficacy of Three Red-NIR Wavelengths in Reducing Oxidative Stress Induced by Impaired Mitochondrial Functions

Oxidative stress in cells can lead to various cellular malfunctions, including apoptosis. Photobiomodulation (PBM), which has been known for its effects in reducing oxidative stress and improving mitochondrial respiration, can thus provide significant therapeutic potential in treating various diseases associated with this stress. A typical example among these possibilities is to improve cell viability, caused by impaired mitochondrial functions and the excessive oxidative stress induced thereby. Although existing studies have indicated that red and near-infrared (NIR) light can reduce oxidative stress, few studies have been devoted to compare the effects of different wavelengths, especially for the cases where damaged mitochondria cannot be repaired. To discover this, an in-vitro cell model was built in this study by inducing mitochondrial damage to cells with rotenone. The damaged cells were irradiated by respectively the 660nm, 780nm and 810nm light at the same fluence. The levels of reactive oxygen species (ROS) before and after the irradiation were measured, respectively in the cases of the cells either damaged by rotenone or not. The results showed that all the studied wavelengths managed to reduce the ROS content with statistical significance, among which the 810nm light turned out to be the most effective. However, none of the studied PBM treatment can restore the ROS level to that of the normal cells. The finding can be informative in further studying the PBM therapies targeted at the diseases associated with oxidative stress induced by impaired mitochondrial functions.