Revisiting the Photon/Cell Interaction Mechanism in Low-Level Light Therapy

Sommer, Andrei P.

doi:10.1089/photob.2018.4606

Cited by 36 publications

(30 citation statements)

References 30 publications

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“…45 Most recently, a number of theories have been proposed that may offer additional insight into the phototransduction processes associated with laser-induced analgesia. 46,47 Pending continued research to further elucidate the best standardized approach, it is apparent that higher range dosimetry is associated with an improved clinical result in PBM-assisted pain management. 48 The result of this review is consistent with PBMT being accepted as an evidenced-based approach for orthodontic pain management.…”

Section: Pbmt: Pain Modulationmentioning

confidence: 99%

Systematic Review of Orthodontic Treatment Management with Photobiomodulation Therapy

Cronshaw

Parker

Anagnostaki

et al. 2019

Photobiomodulation, Photomedicine, and Laser Surgery

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Objective: This systematic review of published research evaluates the parameters and reported outcomes in photobiomodulation therapies (PBMTs) used in management of pain and accelerated tooth movement during orthodontic treatment. Background: Consequent to positive in vitro and animal studies, there has been considerable interest in the potential applications of PBMT to ameliorate pain and to accelerate orthodontic tooth movement. Due to the lack of consistency of wavelengths and parameters applied, there is as yet no consensus in respect of guidance for clinical use. Within the limitations of the reported literature, a digest of key outcomes and parameters is presented here to assist researchers and interested clinicians. Materials and methods: Search engines, PubMed, Google Scholar, and Cochrane, were applied to identify clinical investigations into the potential benefits of PBMTs in orthodontic management. Keywords used were ''low-level laser therapy,'' ''low-level light therapy,'' ''photobiomodulation,'' ''orthodontics,'' ''pain,'' ''tooth movement,'' and ''randomized clinical trial ‡5 years.'' A total of 35 articles were identified, covering the 5-year period January 2013 to December 2018. Only human clinical trials were considered. Seventeen articles were included in this investigation and the reported parameters and outcomes were assessed and presented for comparison. Results: Seven of nine studies supported the effectiveness of PBMT to reduce or prevent pain. There was no consensus on choice of wavelength and a range of parameters were found beneficial. Of the seven tooth movement studies included, four of the seven were positive, of which two used a home-use light-emitting diode (LED) device, as opposed to a clinician-applied laser. A variety of wavelengths and parameters were found to be effective in accelerating tooth movement in the range of 20-40% compared with control. Conclusions: Due to a lack of consistency in approach, further studies are required to achieve a high level of acceptance. The clinical logistics associated with frequent applications supports the concept of patient home delivery use of LED devices, although there are insufficient studies at present to make an evidence-based determination of this type of appliance. To gain more general professional acceptance of the use of PBMT in orthodontics, a continued effort to extend the number of quality human clinical trials is required. Based on the current evidence base, further positive onward progression can be regarded as inevitable.

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Section: Pbmt: Pain Modulationmentioning

confidence: 99%

Systematic Review of Orthodontic Treatment Management with Photobiomodulation Therapy

Cronshaw

Parker

Anagnostaki

et al. 2019

Photobiomodulation, Photomedicine, and Laser Surgery

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“…This information could justify the fact that mitochondrial ATP synthesis can be stimulated by different wavelengths of LED and laser. 16,17 Based on this premise, and partial results obtained by our research group with patients exhibiting bacterial pneumonia, for which we obtained a reduction in hospital stay from 7 to 2 days, for 9 out of 10 treated patients. 18 We propose to treat patients affected by COVID-19 irradiating their thoracic region daily with R-NIR, with 3 J/cm 2 of radiant exposure.…”

mentioning

confidence: 64%

Photobiomodulation: Shining Light on COVID-19

Fernandes

Lima

Villaverde

et al. 2020

Photobiomodulation, Photomedicine, and Laser Surgery

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Objective: To evaluate the hypothesis that light could reduce the lethality of COVID-19. Methods: Most models for projections of the spread and lethality of COVID-19 take into account the ambient temperature, neglecting light. Recent advances in understanding the mechanism of action of COVID-19 have shown that it causes a systemic infection that significantly affects the hematopoietic system and hemostasis, factors extremely dependent of light, mainly in the region of visible and infrared radiation. Results: In the COVID-19 patients hemoglobin is decreasing and protoporphyrin is increasing, generating an extremely harmful accumulation of iron ions in the bloodstream, which are able to induce an intense inflammatory process in the body with a consequent increase in C-reactive protein and albumin. Observing the unsaturation characteristics of the cyclic porphyrin ring allows it to absorb and emit radiation mainly in the visible region. This characteristic can represent an important differential to change this process in the event of an imbalance in this system, through the photobiomodulation to increase the production of adenosine triphosphate (ATP) using red and nearinfrared radiation (R-NIR) and vitamin D using ultraviolet B (UVB) radiation. These two compounds have the primary role of activating the defense mechanisms of the immune system, enabling greater resistance of the individual against the attack by the virus. According to the theory of electron excitation in photosensitive molecules, similar to hemoglobin heme, after the photon absorption there would be an increase in the stability of the iron ion bond with the center of the pyrrole ring, preventing the losses of heme function oxygen transport (HbO 2). The light is also absorbed by cytochrome c oxidase in the R-NIR region, with a consequent increase in electron transport, regulating enzyme activity and resulting in a significant increase of oxygen rate consumption by mitochondria, increasing ATP production. Conclusions: The most favorable range of optical radiation to operate in this system is between R-NIR region, in which cytochrome c oxidase and porphyrin present absorption peaks centered at 640 nm and HbO 2 with absorption peak centered at 900 nm. Based on the mechanisms described earlier, our hypothesis is that light could reduce the lethality of COVID-19.

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“…1,8,35 Recently, however, that hypothesis has been increasingly challenged, 90,91 and a variety of other potential mechanisms and chromophores have been suggested. 2,[92][93][94][95] This study provides several insights regarding light-mediated release of NO and how it may relate to PBM mechanisms. Our finding that multiple wavelengths of light caused release of intracellularly stored NO provides further support that other mechanisms are in play.…”

Section: Discussionmentioning

confidence: 97%

Wavelength- and irradiance-dependent changes in intracellular nitric oxide level

Pope

Powell²,

Wigle

et al. 2020

J. Biomed. Opt.

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Significance: Photobiomodulation (PBM) refers to the beneficial effects of low-energy light absorption. Although there is a large body of literature describing downstream physiological benefits of PBM, there is a limited understanding of the molecular mechanisms underlying these effects. At present, the most popular hypothesis is that light absorption induces release of nitric oxide (NO) from the active site of cytochrome c oxidase (COX), allowing it to bind O 2 instead. This is believed to increase mitochondrial respiration, and result in greater overall health of the cell due to increased adenosine triphosphate production. Aim: Although NO itself is a powerful signaling molecule involved in a host of biological responses, less attention has been devoted to NO mechanisms in the context of PBM. The purpose of our work is to investigate wavelength-specific effects on intracellular NO release in living cells. Approach: We have conducted in-depth dosimetry analyses of NO production and function in an in vitro retinal model in response to low-energy exposure to one or more wavelengths of laser light. Results: We found statistically significant wavelength-dependent elevations (10% to 30%) in intracellular NO levels following laser exposures at 447, 532, 635, or 808 nm. Sequential or simultaneous exposures to light at two different wavelengths enhanced the NO modulation up to 50% of unexposed controls. Additionally, the immediate increases in cellular NO levels were independent of the function of NO synthase, depended greatly on the substrate source of electrons entering the electron transport chain, and did not result in increased levels of cyclic guanosine monophosphate. Conclusions: Our study concludes the simple model of light-mediated release of NO from COX is unlikely to explain the wide variety of PBM effects reported in the literature. Our multiwavelength method provides a novel tool for studying immediate and early mechanisms of PBM as well as exploring intracellular NO signaling networks.

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Revisiting the Photon/Cell Interaction Mechanism in Low-Level Light Therapy

Cited by 36 publications

References 30 publications

Systematic Review of Orthodontic Treatment Management with Photobiomodulation Therapy

Systematic Review of Orthodontic Treatment Management with Photobiomodulation Therapy

Photobiomodulation: Shining Light on COVID-19

Wavelength- and irradiance-dependent changes in intracellular nitric oxide level

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