One of the main effects of PBM Therapy / LLLT is on mitochondrial function: There are hundreds of different cell types in the body, each performing different functions, they all contain lots of mitochondria, (cellular power plants) which generate most of the cell’s supply of energy (ATP). Mitochondria are also involved in a range of other cellular processes, including signalling, stem cell differentiation, inflammation, cell survival, apoptosis and are consequently implicated in many diseases.

Mitochondria in stressed or ischaemic tissues produce too much mitochondrial nitric oxide (mtNO) which binds to cytochrome c oxidase, competitively displacing oxygen and consequently reducing ATP, but this inhibition of mitochondrial respiration significantly increases production of ROS (free radicals). These excess ROS trigger the process of inflammation, cell death and subsequently oral mucositis.

Light of the correct wavelength (generated by low intensity lasers and LED’s), when applied to stressed tissues, is absorbed by cytochrome c oxidase. The light displaces the mtNO thereby reducing oxidative stress and increasing ATP production; this reduces inflammation and increases cell metabolism.

The subsequent cascade of downstream metabolic effects have been shown to include changes in gene transcription (NF-kB and AP-1), activation of latent TGF-β1, increased exchange of Ca2+, secretion of growth factors, activation of enzymes & many secondary messengers.

Within hours (and sometimes minutes) following PBM Therapy / LLLT, increases in cellular activity have been shown in vitro and in vivo in neutrophils, macrophages, fibroblasts, mast cells, endothelial cells and keratinocytes. Reduced inflammatory markers including prostaglandin E2, interleukin 1ß and TNFα have also been seen in many studies.

Clinical trials show a significant improvement in healing of wounds and reduction of pain. A recent systematic review on PBM Therapy / LLLT for OM found that it reduces pain, severity and duration of chemotherapy and radiotherapy induced oral mucositis.

The Multinational Association of Supportive Care in Cancer (MASCC) now recommend PBM Therapy / LLLT for the prevention of oral mucositis in adult patients receiving hematopoietic stem cell transplantation conditioned with high-dose chemotherapy. A new suggestion was made for low-level laser for the prevention of oral mucositis in patients undergoing radiotherapy, without concomitant chemotherapy, for head and neck cancer.