Low-Intensity Light Therapy: Exploring the Role of Redox Mechanisms
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2996814/
- This study explores how and why we see changes like increased ATP Production from the mitochondria as a result of redox reactions. It looks into how light therapy can lead to cellular homeostasis
- Probably the main reason why light therapy seems to affect processes like ATP production is because of the photoreceptor cytochrome C oxidase (CCO), which acts as a photoreceptor to low-level red and near infrared light.
- Photoexcitation of CCO in the mitochondrial electron transport chain then alters cellular function, through increased metabolism and the generation of reactive oxygen species.
- It also appears that the initial redox state of cells can influence their photosensitivity
- The idea of redox mechanisms being influenced by light can “explain why some cells in pro-oxidant states, such as those that are chronically inflamed, are more sensitive to LILT.”
- “In such a scenario, these processes would provide the energy and the direction to restore redox homeostasis and improve cell functioning.”
Low-level laser (light) therapy increases mitochondrial membrane potential and ATP synthesis in C2C12 myotubes with a peak response at 3-6 hours
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4355185/
- 850±20 nm and 630±10 nm used in this study
- Found that peak ATP synthesis occurs 3-6 hours after light is applied to skin (in vitro experiment)
- Used mouse muscle cells grown in cell culture
- “The light dose used was based on previous study that already reported benefits of LLLT on mitochondria of myotubes” (This one: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4355185/ )
- “Possibly these relatively modest increases [in other studies] could be due to allowing insufficient time necessary for the muscle cells to convert light therapy into biological responses as identified in our study for MMP and ATP synthesis. Consequently, protocols for muscular pre-conditioning that have been done up to now, i.e., generally applying light 5 minutes before the exercise, may not possibly achieve the best result. Based on our results, we suggest to wait 3h to 6h after light therapy irradiation to obtain the best increase in muscle performance in muscular pre-conditioning regimen, since MMP and ATP availability are important for muscle performance. One more time, we would like to remark the need for more studies in vivo and clinical trials to confirm our hypotheses.”
- How much more ATP was produced by these muscle cells treated with light? Study found that it was 200 – 350% greater than the control studies
- Significant increases were found at 24 hours (and 3 and 6 hours, which were the most optimal), but 5 minutes was not, suggesting the delayed reaction of cells to light therapy
Proposed Mechanisms of Photobiomodulation or Low-Level Light Therapy
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5215870/
- Explores some more of the mechanisms behind light affecting ATP production in the mitochondria.
- One of the leading hypotheses is that the light photons break apart nitric oxide from the cytochrome c oxidase enzyme, leading to an increase in electron transport, mitochondrial membrane potential, and ATP production.
- Another hypothesis concerns light-sensitive ion channels that can be activated when light is shown on cells which allows calcium to enter the cell. After the initial photon is absorbed, numerous signaling pathways are activated via reactive oxygen species, cyclic AMP, NO and Ca2+, leading to activation of transcription factors (these allow DNA to be transcribed to RNA). These transcription factors can lead to increased expression of genes related to protein synthesis, cell migration and proliferation, anti-inflammatory signaling, anti-apoptotic proteins, antioxidant enzymes.
- Empirical evidence suggests stem cells and progenitor cells (which are like stem cells but usually can only generate into specific types of cells, as opposed to any cell; in other word, a slightly more specialized stem cell) are most susceptible to LLLT
- Here’s something interesting:
“An increase in intracellular ATP is one of the most frequent and significant findings after PBM both in vitro and in vivo. The stimulated synthesis of ATP is caused by an increased activity of Cox when activated by light. According to Ferraresi et al., increased Cox activity is the mechanism of enhanced muscle performance when PBM is carried out before various types of exercises, for example. The authors found an increased ATP synthesis after LED (850±20 nm and 630±10 nm) therapy in different muscles (one with a predominantly aerobic metabolism, and other with mixed aerobic and glycolytic metabolism), just like previous data from Ferraresi et al.”
- Quote is based off second study (the one above this one) on this document
Mitochondrial cytochrome c oxidase is not the primary acceptor for near infrared light-it is mitochondrial bound water: the principles of low-level light therapy.
https://europepmc.org/article/pmc/pmc6462613
- Interesting take on mitochondria and cytochrome c oxidase. This article says: “Mitochondrial cytochrome c oxidase is not the primary acceptor for near infrared light; it is mitochondrial bound water”
- Most scientific papers don’t agree with the assessment made in this paper. While it was released in very recently, 2019, I still was not able to find any corroborating evidence or papers that agreed/aligned with the ideas in this paper.
Time Response of Increases in ATP and Muscle Resistance to Fatigue After Low-Level Laser (Light) Therapy (LLLT) in Mice
https://pubmed.ncbi.nlm.nih.gov/25700769/
- This article details how 6 hours following low- level light therapy allowed for maximum benefit in terms of muscle resistance and ATP production. This is as a result of ATP increases due to mitochondria
- Although the study was done on mice in vivo, which is better than the above study done on mouse cells in vitro
- “Although the time response in mice and humans is not the same, athletes might consider applying LEDT at 6 h before competition.”
- They used a cluster of LEDs with 20 red (630±10 nm, 25 mW) and 20 infrared (850±20 nm, 50 mW) delivering 80 mW/cm2 for 90 s (7.2 J/cm2) applied to legs, gluteus, and lower back muscles.
- The second best group was the 3 hour group of mice, which corroborates the other study above. The 24 hour group was the next best (still had statistically significant difference, although small) and the 5 minute group had no statistical difference when compared to sham (control) group.
Primary and secondary mechanisms of action of visible to near-IR radiation on cells (Karu)
https://www.sciencedirect.com/science/article/abs/pii/S1011134414002541?via%3Dihub
- Cited from above study as an example (in fact it appears to be one of the first I could find) of in vitro example of increased ATP production
- They found that a variety of biomolecules in mitochondria including cytochrome C oxidase, some proteins, nucleic acids and adenine nucleotides are light sensitive with major modifications in their biochemistry.
- This is important because it shows that light therapy can affect mitochondria and its functions
- The study used either laser or narrow band light (in this case both low power He–Ne laser with k = 632.8 nm, and non-coherent red light LED k = 650 ± 20 nm, were used).
- There were several tests used to determine how light sensitive these biomolecules were by combining research on this topic from several papers and aggregating/analyzing results. Most results showed positive correlation with light therapy/photobiomodulation including ATP production, # of mitochondria, mitochondria density, muscle regeneration, among other things.
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Older articles still related to ATP:
Ga-As (808 Nm) Laser Irradiation Enhances ATP Production in Human Neuronal Cells in Culture
https://pubmed.ncbi.nlm.nih.gov/17603858/
ATP 808nm
Differential Response of Human Dermal Fibroblast Subpopulations to Visible and Near-Infrared Light: Potential of Photobiomodulation for Addressing Cutaneous Conditions
https://pubmed.ncbi.nlm.nih.gov/29665018/
ATP lots of wavelengths
Red (660 Nm) or Near-Infrared (810 Nm) Photobiomodulation Stimulates, While Blue (415 Nm), Green (540 Nm) Light Inhibits Proliferation in Human Adipose-Derived Stem Cells
https://pubmed.ncbi.nlm.nih.gov/28798481/
ATP superiority of red over blue green 2017
Effect of Near-Infrared Light on in vitro Cellular ATP Production of Osteoblasts and Fibroblasts and on Fracture Healing With Intramedullary Fixation
https://pubmed.ncbi.nlm.nih.gov/27857496/
660 was better than 830 at atp production
Summary (old): Some interesting things involving ATP. Max ATP production occurs 3-6 hours after red light is shone onto the body. Many use a combination of 2 lights in experiments. One paper ties the increase in ATP/other benefits of Red Light Therapy to redox reactions, which you may want to look at.
