Effects of Low-Level Light Therapy (LLLT) on Oxidative Stress in the Cutaneous Healing Process: A Literature Review

Introduction: Photobiomodulation (PBM), initially called low-level light therapy (LLLT), is defined as the application of radiation in the form of light for healing since it can modify the cell's behavior to facilitate repair of the tissue. The objective of this review study was to research the known effects of the LLLT on oxidative stress, as well as mitochondrial activity, in the cutaneous healing process. Methods: We included experimental animal studies that evaluated the effects of the LLLT on the oxidative stress related to the cutaneous healing process. In December 2023, research into the literature was conducted in the following databases: PubMed, Embase, and Web of Science. The methodological quality of the studies was evaluated by the adapted PEDro scale. Additionally, a qualitative and descriptive analysis of the included studies was made. Results: Nine studies were included, and all the articles presented significant modulation of oxidative stress, with reductions in oxidizing markers (superoxide anion) and apoptosis activators (cytochrome c), and mainly, increases in antioxidant enzymatic defense (catalase, superoxide dismutase, and glutathione peroxidase). Conclusion: LLLT represents a technique with promising results in the improvement and acceleration of the cutaneous healing process, as well as in the regulation of biochemical reactions related to oxidative stress of the treated areas. Despite that, more studies focusing on the central role of mitochondria in explaining the therapeutic effects of LLLT are necessary.