Low-intensity Red Light Research Articles

Ultrastructure of Myofascial Trigger Points of Skeletal Muscles of Rats after Photobiostimulation with Low-Intensity Red Light.

The effectiveness of low-intensity red light on myofascial trigger points in skeletal muscle of mature rats was evaluated by electron microscopy and high-resolution respirometry. The revealed changes in mitochondrial ultrastructure and activity of the respiratory chain enzymes indicate the development of hypoxia in the simulation area. Under the influence of low-intensity red light on myofascial trigger points, a decrease in the number of destructively altered muscle fibers and stimulation of mitochondrial respiration were found. These findings indicate intracellular regeneration and the stimulating effect of low-intensity red light on plastic processes.

Efficacy of Different Powers of Low-Level Red Light in Children for Myopia Control

To compare the efficacy and safety of low-level red light (LRL) in controlling myopia progression at 3 different powers: 0.37 mW, 0.60 mW, and 1.20 mW. Single-center, single-masked, randomized controlled trial. Two hundred children aged 6-15 with myopia of -0.50 diopter (D) or more and astigmatism of -2.50 D or less were enrolled from April to May 2022. Follow-up ended in December2022. Participants were assigned randomly to 3 intervention groups and 1 control group (1:1:1:1). All participants wore single-vision spectacles. Moreover, the intervention group randomly received LRL at 3 different powers twice daily for 3 minutes per session, with a minimum 4-hour interval. Changes in spherical equivalent (SE), axial length (AL), and subfoveal choroidal thickness (SFCT) were measured. After 6 months, SE progression was significantly lower in the 0.37-mW group (0.01 D; 95% confidence interval [CI], -0.12 to 0.15), 0.60-mW group (-0.05 D; 95% CI, -0.18 to 0.07), and 1.20-mW group (0.16D; 95% CI, 0.03 to 0.30) compared to the control group (-0.22 D; 95% CI, -0.50 to 0.30; adjusted P<0.001 for all). AL changes in the 0.37-mW group (0.04 mm; 95% CI, -0.01 to 0.08), 0.60-mW group (0.00 mm; 95% CI, -0.05 to 0.05), and 1.20-mW group (-0.04 mm; 95% CI, -0.08 to 0.01) were significantly smaller than the control group (0.27 mm; 95% CI, 0.22 to 0.33; adjusted P < 0.001 for all). Similarly, increases in SFCT were significantly greater in the 0.37-mW group (22.63 μm; 95% CI, 12.13 to 33.34 μm), 0.60-mW group (36.17 μm; 95% CI, 24.37 to 48.25 μm), and 1.20-mW group (42.59 μm; 95% CI, 23.43 to 66.24 μm) than the control group (-5.07 μm; 95% CI, -10.32 to -0.13 μm; adjusted P < 0.001 for all). No adverse events were observed. LRL effectively controlled myopia progression at 0.37 mW, 0.60 mW, and 1.20 mW. Further research is required. The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Photosensitiser-incorporated microparticles for photodynamic inactivation of bacteria.

Antimicrobial resistance is an ever-growing global concern, making the development of alternative antimicrobial agents and techniques an urgent priority to protect public health. Antimicrobial photodynamic therapy (aPDT) is one such promising alternative, which harnesses the cytotoxic action of reactive oxygen species (ROS) generated upon irradiation of photosensitisers (PSs) with visible light to destroy microorganisms. In this study we report a convenient and facile method to produce highly photoactive antimicrobial microparticles, exhibiting minimal PS leaching, and examine the effect of particle size on antimicrobial activity. A ball milling technique produced a range of sizes of anionic p(HEMA-co-MAA) microparticles, providing large surface areas available for electrostatic attachment of the cationic PS, Toluidine Blue O (TBO). The TBO-incorporated microparticles showed a size-dependent effect on antimicrobial activity, with a decrease in microparticle size resulting in an increase in the bacterial reductions achieved when irradiated with red light. The >6 log10Pseudomonas aeruginosa and Staphylococcus aureus reductions (>99.9999%) achieved within 30 and 60min, respectively, by TBO-incorporated >90μm microparticles were attributed to the cytotoxic action of the ROS generated by TBO molecules bound to the microparticles, with no PS leaching from these particles detected over this timeframe. TBO-incorporated microparticles capable of significantly reducing the bioburden of solutions with short durations of low intensity red light irradiation and minimal leaching present an attractive platform for various antimicrobial applications.

Effects of leaf-spreading on the volatile aroma components of green tea under red light of different intensities

Spreading is an indispensable process in the aroma formation of green tea. The application of exogenous red-light spreading in tea processing has been verified to significantly improve the aroma of green tea, and endow tea with freshness, sweet flavor, and mellow taste. However, there were no previous studies investigating the effects of spreading with different red-light intensities on the aroma components of green tea. The aim of the present study was to evaluate the effect of the relationship between the aroma component and spreading with different red-light intensities (300 μmol∙m−2∙s−1, 150 μmol∙m−2∙s−1 and 75 μmol∙m−2∙s−1). As a result, a total of ninety-one volatile components were identified in this study. The orthogonal partial least squares discriminant analysis (OPLS-DA) model clearly distinguished the volatile components of green tea between different red-light intensities and obtained thirty-three differential volatile compounds. Combined with odor activity value (OAV > 1) analysis revealed that eleven volatile components were the key volatile compounds of green tea under different light conditions. Among them, 3-methyl-butanal, (E)-nerolidol, and linalool were the sources of chestnut-like aroma in green tea and were significantly accumulated under medium (MRL) and low intensity (LRL) red light. The results of the present study provided a theoretical basis that could guide green tea processing with red-light intensities to increase the aroma quality components of green tea.

The effects of light regime on carbon cycling, nutrient removal, biomass yield, and polyhydroxybutyrate (PHB) production by a constructed photosynthetic consortium

Microalgae can add value to biological wastewater treatment processes by capturing carbon and nutrients and producing valuable biomass. Harvesting small cells from liquid media is a challenge easily addressed with biofilm cultivation. Three experimental photobioreactors were constructed from inexpensive materials (e.g. plexiglass, silicone) for hybrid liquid/biofilm cultivation of a microalgal-bacterial consortia in aquaculture effluent. Three light regimes (full-spectrum, blue-white, and red) were implemented to test light spectra as a process control. High-intensity full-spectrum light caused photoinhibition and low biomass yield, but produced the most polyhydroxybutyrate (PHB) (0.14 mg g−1); a renewable bioplastic polymer. Medium-intensity blue-white light was less effective for carbon capture, but removed up to 82 % of phosphorus. Low-intensity red light was the only net carbon-negative regime, but increased phosphorus (+4.98 mg/L) in the culture medium. Light spectra and intensity have potential as easily-implemented process controls for targeted wastewater treatment, biomass production, and PHB synthesis using photosynthetic consortia.

Low-intensity red-light therapy in slowing myopic progression and the rebound effect after its cessation in Chinese children: a randomized controlled trial.

To investigate the effect of low-intensity red-light (LRL) therapy on myopic control and the response after its cessation. A prospective clinical trial. One hundred two children aged 6 to 13 with myopia were included in the LRL group (n = 51) and the single-focus spectacles (SFS) group (n = 51). In LRL group, subjects wore SFS and received LRL therapy provided by a laser device that emitted red-light of 635nm and power of 0.35 ± 0.02 mW. One year after the control trial, LRL therapy was stopped for 3months. The outcomes mainly included axial length (AL), spherical equivalent refraction (SER), subfoveal choroidal thickness (SFCT), and accommodative function. After 12months of therapy, 46 children in the LRL group and 40 children in the SFS group completed the trial. AL elongation and myopic progression were 0.01mm (95%CI: - 0.05 to 0.07mm) and 0.05 D (95%CI: - 0 .08 to 0.19 D) in the LRL group, which were less than 0.39mm (95%CI: 0.33 to 0.45mm) and - 0.64 D (95%CI: - 0.78 to - 0.51 D) in the SFS group (p < 0.05). The change of SFCT in the LRL group was greater than that in the SFS group (p < 0.05). Accommodative response and positive relative accommodation in the LRL group were more negative than those in the SFS group (p < 0.05). Forty-two subjects completed the observation of LRL cessation, AL and SER increased by 0.16mm (95%CI: 0.11 to 0.22mm) and - 0.20 D (95%CI: - 0.26 to - 0.14 D) during the cessation (p < 0.05), and SFCT returned to baseline (p > 0.05). LRL is an effective measure for preventing and controlling myopia, and it may also have the ability to improve the accommodative function. There may be a slight myopic rebound after its cessation. The effect of long-term LRL therapy needs to be further explored. Chinese Clinical Trial Registry: Chinese Clinical Trails registry: ChiCTR2100045250. Registered 9 April 2021; retrospectively registered. http://www.chictr.org.cn/showproj.aspx?proj=124250.

"Fundamental principles of photodynamic, laser and PUVA therapy": a session of the Russian Photobiology Society 9th Congress (Shepsi, Krasnodar region, Russia; September, 12-19, 2021).

At the section "Fundamentals of photodynamic, laser and PUVA therapy," 32 reports were presented in full-time and on-line format. Representatives of various scientific schools reported on the results of fundamental and applied research on the processes occurring at the cellular and organismal levels upon irradiation with low-intensity red light and upon the introduction of photosensitizers of various nature, followed by laser irradiation. Scientific reports proposed new photosensitizers, as well as their conjugates with biologically active molecules for fluorescent diagnostics and photodynamic therapy of oncological diseases. Plenary reports were presented by Professor Mikhail Grin "Natural chlorins as a promising platform for creating drugs with photoinduced antitumor and antimicrobial activity," Professor Alexander Krasnovsky "Laser activation of dissolved oxygen in natural conditions," and Professor Elena Filonenko "Photodynamic therapy in the treatment of demodicosis of the facial skin with topical application of a gel based on 5-ALA." At the poster section, young scientists presented 18 posters, which describe in detail the research voiced in the section reports.

Possibilities of Using Low-Intensity Red Light for Modulation of Post-Arrhythmia Processes in the Rat Heart

Possibilities of Using Low-Intensity Red Light for Modulation of Post-Arrhythmia Processes in the Rat Heart

Irradiation with Low-Intensity Red Light Rescues Murine Brain Mitochondrial Respiration after Acute Hypobaric Hypoxia

Irradiation with Low-Intensity Red Light Rescues Murine Brain Mitochondrial Respiration after Acute Hypobaric Hypoxia

Effects of photobiomodulation in relation to HeLa Kyoto tumor cells exposed to ionizing radiation

The aim of the work was studying the effects of photobiomodulation of a red spectrum in doses of less than 1 J/cm2 in combination with gamma-irradiation to Hela Kyoto cells. Tumor cells were irradiated with 640 nm LED at different energy densities before and after to gamma-irradiation. Cells viability was determined 24 h after exposure for each gamma-irradiation dose and each PBM mode. There was a statistically significant decrease in a number of viable tumor cells for the samples that were exposed to low-intensity red light prior to gamma-irradiation and a statistically significant increase in a number of viable tumor cells for the samples that were exposed to low-intensity red light after gamma-irradiation. An increase in the number of viable tumor cells exposed to PBM after gamma irradiation correlates with a decrease in the number of cells with a depolarized mitochondrial membrane. The results of a current study need to take into consideration at further studies of PBM effects on tumor cells in vitro as far as clinical studies and clinical application of PBM during radiation therapy.

Photochemical activity of chloroplasts of isogenic lines (E genes) of soybean (Glycine max (L.) Merr.) under different periods of red-light irradiation

The effect of different periods of red-light (RL, 660 nm) irradiation of plants on the biomass, leaf area, chlorophyll content, level of the Hill reaction and photophosphorylation in short-day (SD) and photoperiodical neutral (PhPN) lines of soybean have been studied in vegetation experiments. The objects of study were the isogenic lines (E genes) of soybean (Glycine max (L.) Merr.), Clark variety. The SD (E1E2E3) and PhPN lines (e1e2e3) were used. The plants were grown in a vegetation chamber in the soil culture (black soil). Plants of SD and PhPN lines were grown in 9 vessels of three liters volume. 10–12 plants were grown in each vessel. The constant growing conditions were provided during the experiment: temperature – 20–24/17–20°С (day/night), soil moisture – 60–70 % of the total soil moisture content, intensity of illumination – 20 klx, photoperiod duration – 10 hours. After 4–5 weeks of vegetation (after the second true leaf formation), plants of each line in three vessels were irradiated for 30 minutes with low intensity red light at the beginning (experiment 1) or in the middle of the dark period (experiment 2). The light diodes emitting in the region of 630±10 nm were used for plant irradiation. Other plants in three vessels of each line, which were not illuminated by the red light, were used as a control group. It was shown that under the short day the SD line in the control group passed to flowering 43±1.8 days after germination and PhPN line – 44±2.2 days after germination. The red-light irradiation, both before the beginning and in the middle of night, caused a delay of the transition to flowering in the SD line by 5±1 and 7±2.2 days, respectively. In the PhPN line, changing flowering period due to RL was not established. In the SD line, activation of the phytochromes by RL before the dark period caused an increase of the biomass, leaf area, total chlorophyll content, reduction of potassium ferrocyanide and photophosphorylation by isolated chloroplasts per chlorophyll of one leaf. While interruption of the night by RL caused decrease of these parameters and Hill reaction intensity per 1 mg of chlorophyll. The effect of RL on the studied parameters in the PhPN soybean line has not been detected.

Opposite effects of low intensity light of different wavelengths on the planarian regeneration rate

Planarian freshwater flatworms have the unique ability to regenerate due to stem cell activity. The process of regeneration is extremely sensitive to various factors, including light radiation. Here, the effect of low-intensity LED light of different wavelengths on regeneration, stem cell proliferation and gene expression associated with these processes was studied. LED matrices with different wavelengths (red (λmax = 635 nm), green (λmax = 520 nm) and blue (λmax = 463 nm), as well as LED laser diodes (red (λmax = 638.5 nm), green (λmax = 533 nm) and blue (λmax = 420 nm), were used in the experiments. Computer-assisted morphometry, whole-mount immunocytochemical study and RT-PCR were used to analyze the biological effects of LED light exposure on the planarian regeneration in vivo. It was found that a one-time exposure of regenerating planarians with low-intensity red light diodes stimulated head blastema growth in a dose-dependent manner (up to 40%). The green light exposure of planarians resulted in the opposite effect, showing a reduced head blastema growth rate by up to 21%. The blue light exposure did not lead to any changes in the rate of head blastema growth. The maximum effects of light exposure were observed at a dose of 175.2 mJ/cm2. No significant differences were revealed in the dynamics of neoblasts' (planarian stem cells) proliferation under red and green light exposure. However, the RT-PCR gene expression analysis of 46 wound-induced genes revealed their up-regulation upon red LED light exposure, and down-regulation upon green light exposure. Thus, we have demonstrated that the planarian regeneration process is rather sensitive to the effects of low-intensity light radiation of certain wavelengths, the biological activity of red and green light being dictated by the different expression of the genes regulating transcriptional activity.

Photobiomodulation Mitigates Cerebrovascular Leakage Induced by the Parkinsonian Neurotoxin MPTP.

The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is commonly used to model Parkinson’s disease (PD) as it specifically damages the nigrostriatal dopaminergic pathway. Recent studies in mice have, however, provided evidence that MPTP also compromises the integrity of the brain’s vasculature. Photobiomodulation (PBM), the irradiation of tissue with low-intensity red light, mitigates MPTP-induced loss of dopaminergic neurons in the midbrain, but whether PBM also mitigates MPTP-induced damage to the cerebrovasculature has not been investigated. This study aimed to characterize the time course of cerebrovascular disruption following MPTP exposure and to determine whether PBM can mitigate this disruption. Young adult male C57BL/6 mice were injected with 80 mg/kg MPTP or isotonic saline and perfused with fluorescein isothiocyanate FITC-labelled albumin at various time points post-injection. By 7 days post-injection, there was substantial and significant leakage of FITC-labelled albumin into both the substantia nigra pars compacta (SNc; p < 0.0001) and the caudate-putamen complex (CPu; p ≤ 0.0003); this leakage partly subsided by 14 days post-injection. Mice that were injected with MPTP and treated with daily transcranial PBM (670 nm, 50 mW/cm2, 3 min/day), commencing 24 h after MPTP injection, showed significantly less leakage of FITC-labelled albumin in both the SNc (p < 0.0001) and CPu (p = 0.0003) than sham-treated MPTP mice, with levels of leakage that were not significantly different from saline-injected controls. In summary, this study confirms that MPTP damages the brain’s vasculature, delineates the time course of leakage induced by MPTP out to 14 days post-injection, and provides the first direct evidence that PBM can mitigate this leakage. These findings provide new understanding of the use of the MPTP mouse model as an experimental tool and highlight the potential of PBM as a therapeutic tool for reducing vascular dysfunction in neurological conditions.

Red light at night permits the nocturnal rise of melatonin production in horses

Exposure to white light at night suppresses melatonin production, impacts circadian rhythms and contributes to ill-health in humans. Human interaction with horses frequently occurs at night. We tested the hypothesis that dim red light would not suppress the nightly rise in serum melatonin levels in horses. In a crossover design, six horses were maintained for consecutive 48h periods under a Light: Red (LR) and a Light: Dark (LD) photo-schedule. Transitions from light (>200lux, polychromatic white light) to red (5lux, peak wavelength 625nm) or dark (<0.5lux), and vice versa, coincided with ambient sunset and sunrise times. Blood was collected at 2h intervals for 24h during each treatment via indwelling jugular catheters. Samples were harvested for serum and stored at −20°C until assayed for melatonin by radioimmunoassay. Repeated measures two-way ANOVA and t-tests analysed for differences in LR and LD melatonin profiles and their circadian rhythm parameters.No time×treatment interaction or effect of treatment on serum melatonin levels were demonstrated (P>0.05). A robust main effect of time (P<0.0001) predominated, with melatonin levels rising at night under both treatments. Statistically significant differences were not observed when LR and LD were compared for circadian rhythm measures of night time peak, area under the curve (AUC), or for times of onset (evening rise), offset (morning decline), or peak duration. Low intensity red light at night did not impact the pattern of melatonin secretion in this study and is, therefore, unlikely to impact the physiology of circadian or seasonal regulation.

Visual Degree of Doneness Impacts Beef Palatability for Consumers with Different Degree of Doneness Preferences

The objective of this study was to determine the impact on beef palatability perceptions when consumers with varying degree of doneness (DOD) preferences are served steaks cooked to multiple DOD. Paired Low Choice strip loin steaks were randomly assigned to a DOD of either rare (60°C), medium-rare (63°C), medium (71°C), medium-well (74°C), or well-done (77°C). Consumer panelists were prescreened for DOD preference (rare, medium, or well-done) prior to sensory panels and were assigned to panels based on their DOD preference. In the first round of testing, consumers were served 1 sample from each of the 5 DOD under low-intensity red incandescent light to mask any DOD differences among samples. In round 2 of testing, consumers were fed the paired samples cooked to the same DOD under white incandescent lights. There were no (P &gt; 0.05) consumer DOD preference × steak DOD interactions or consumer DOD preference effects for tenderness, juiciness, and flavor ratings when steaks were evaluated under both lighting types. Within the white-lighting testing, there was a consumer DOD preference × steak DOD interaction (P &lt; 0.05) for overall acceptability. Consumers who preferred steaks cooked to well-done reported no differences (P &gt; 0.05) in overall palatability among DOD under white-lighting, whereas consumers who preferred steaks cooked to rare and medium rated steaks lower (P &lt; 0.05) for overall palatability as DOD increased. Regardless of DOD preference, consumer sensory ratings decreased (P &lt; 0.05) when steaks were cooked above the consumer’s preferred DOD; whereas sensory ratings improved (P &lt; 0.05) when steaks were served below the consumers’ preferences. These results indicate that overcooking steaks has the greatest negative impact on beef palatability perception and thus, foodservice should err on the side of undercooking steaks to preserve, and potentially improve, eating satisfaction.

Nitrogen utilization during germination of somatic embryos of Norway spruce: revealing the importance of supplied glutamine for nitrogen metabolism

Key messageThis paper shows that germinating Norway spruce somatic embryos are dependent on the carbon and nitrogen supplied in the medium, and that supplied glutamine accounts for 50 % of assimilated nitrogen during germination.The female megagametophyte, which provides the zygotic embryo with nitrogen (N), carbon (C) and energy during germination, is not present in Norway spruce (Picea abies) mature somatic embryos. Therefore, somatic embryos presumably rely on nutrients supplied in the germination medium in addition to their storage compounds accumulated during maturation. However, to what extent stored versus supplied compounds contribute to a somatic embryo germination is unclear. In this 24-day study, we addressed the above question by monitoring the biomass changes and the N and C budget during somatic embryo germination, under low-intensity red light. We found that the C and N storage reserves, accumulated during the maturation phase, were not sufficient to support the growth of the germinating somatic embryos, rather they were dependent on the medium components. In addition, in a previous study it has been found that glutamine (Gln) supplied in the medium was crucial for maintaining the primary amino acid (AA) metabolism and growth of the proliferating embryogenic cultures of Norway spruce (Carlsson et al., PLoS One 12(8):e0181785, 2017). Therefore, we hypothesised that Gln would be required as a significant source of N also during somatic embryo germination. By tracing the uptake of isotopically labelled N-sources from the medium and further into primary N assimilation, we found that Gln was the preferred source of N for the germinating somatic embryos, accounting for 50% of assimilated N. As the amounts of both arginine (Arg) and Gln were increased in the germinating somatic embryos, it also suggested that germination in low-intensity red light promoted N storage, similar to what has been observed in the zygotic embryo maturation in conifers (King, Gifford, Plant Physiol 113:1125–1135, 1997).

Blue and red light effects on stomatal oscillations.

The response of stomata to red and blue light was investigated using small fibre optics (66µm diameter) to control light levels on a single pair of guard cells without affecting the surrounding tissue. Low intensity red light (50µmolm-2s-1) applied to the entire leaf caused stomata to oscillate continuously for several hours with no apparent decrease in amplitude with time. Adding low intensity blue light (50µmolm-2s-1) caused stomata to stop oscillating, but oscillations resumed when the blue light was removed. Adding the same intensity of red light to an oscillating leaf changed the amplitude of the oscillations but did not stop them. When blue light was added to a single guard cell pair (using a fibre optic) in a red-light-illuminated leaf, the stoma formed by that pair stopped oscillating, but adjacent stomata did not. Red light added to a single guard cell pair did not stop oscillations. Finally, blue light applied through a fibre optic to areas of leaf without stomata caused proximal stomata to stop oscillating, but distal stomata continued to oscillate. The data suggest that blue light affects stomata via direct effects on guard cells as well as by indirect effects on other cells in the leaf.

Influence of Low-Intensive Red Light on the Myocardium in Experimental Asphyxia.

We studied the effects of low-intensity broadband red light on electrical activity of the heart and oxidative modification of proteins in the myocardium of rats after asphyxia. It was shown that low-intensity red light reduced the content of oxidatively modified proteins in rat heart after oxidative stress caused by asphyxia. Exposure to low-intensity red light normalized ECG parameters in rats after asphyxia.

Eu(III) doped LDH intercalated with cinnamate anion as multifunctional sunscreens

Eu(III) doped Zn2Al-LDH intercalated with cinnamate anions with different C9H7O2-/M3+ molar ratios were synthesized by different anion-exchange methods. The XRD patterns indicate the formation of hydrotalcite-like compounds. UV–VIS absorption spectra show that the hybrid materials obtained have UV shielding capacity. PLS measurements show low-intensity red light emission of the characteristic europium and cinnamate ions that is recommended to induce collagen production.

ВЛИЯНИЕ НИЗКОИНТЕНСИВНОГО КРАСНОГО СВЕТА НА ОКИСЛИТЕЛЬНУЮ МОДИФИКАЦИЮ БЕЛКОВ ПРИ РАЗВИТИИ РАДИАЦИОННО-ИНДУЦИРОВАННОЙ БОЛЕЗНИ ЛЕГКИХ В ЭКСПЕРИМЕНТЕ

The aim of the study was to investigate the content of spontaneous protein oxidative modification (POM) in the blood serum and pulmonary tissue of rats after local gamma irradiation of the projection area of the heart and lungs. The content of products of spontaneous POM (aliphatic neutral and basic aldehyde- and ketone-dinitrophenylhydrazones) in the blood serum and pulmonary tissue of 57 rats was studied. The animals were divided into 5 groups: “control group”, where there was gamma irradiation of the heart and lungs area, the collection of samples was done at the next day; “treatment group”, where a single session of low-intensity broadband red light was performed after local exposure to gamma radiation (the collection of samples was done at the next day); “chronic control group”, where there was an exposure to local gamma irradiation of the heart and lungs area, the collection of samples was done at the fourth day; “chronic treatment group” was daily exposed to low-intensity red light for 4 days after local exposure to gamma radiation, the collection of samples was done at the fourth day; “normal level group” was not exposed to either gamma radiation or broadband red light. In the pulmonary tissue and blood serum of control animals, a gradual increase in the content of spontaneous POM products was observed. The most significant difference from the normal level the “chronic control group” had. At the same time, the normalization of the content of POM products under the influence of low-intensity broadband red light in the tissues of the experimental groups was revealed. In the course of the experimental study, the normalization of processes of free radical oxidation of proteins in the lung tissue and in the serum of rats after gamma irradiation and the exposure of the projection region of the heart and lungs to low-intensity broadband red light was shown. Thus, low-intensity red light can be considered as a possible radioprotector.