A comparison of the effects of laser and light-emitting diodes on superoxide dismutase activity and nitric oxide production in rat wound fluid

The action of laser and light-emitting diode radiation in the visible region on the content of reactive nitrogen species and activity of superoxide dismutase in rat wound fluid was studied, and efficiency of action of coherent laser and incoherent light emitting diode radiations in the red region of the spectrum on the parameters under study was compared. A model of incised aseptic wounds in rats proposed by L.I. Slutskiy was used. A He-Ne laser (632 nm) and a Y-332B light emitting diode served as radiation sources. It was shown that (1) exposure of wounds to the visible light of both laser and light-emitting diodes causes dose-dependent changes in superoxide dismutase activity and production of nitrites and (2) the radiation coherence does not play any significant role in the changes of superoxide dismutase activity or nitrogen oxide formation by wound fluid phagocytes.     

Comparison of the effects of laser and light-emitting diodes on lipid peroxidation in rat wound exudate

The effect of laser and light-emitting diode radiation on lipid peroxidation in rat wound exudate was studied with the aim to compare the efficiency of coherent laser and incoherent light-emitting diode radiations. A model of aseptic wound in rat suggested by L.I. Slutskii was used. A He-Ne laser (632 nm) and a U-332B light-emitting diode were used in this study. The intensity of lipid peroxidation was estimated by the TBA assay. The antioxidative capacity of rat wound fluid was evaluated by means of chemiluminescent assays in two model systems: a) aqueous system with ABAP and luminol and b) in phospholipid liposome suspension with Fe2+ and cumarin. It was shown that exposure of rat wounds to both laser and light-emitting diode radiation decreased the concentration of TBA products and increased the antioxidative capacity of wound exudates, compared with the control group (without irradiation). The results obtained show that exposure of wounds to both laser and light-emitting diode irradiation causes a decrease in the oxidative stress in the rat wound fluid. No significant quantitative difference between the effects of laser and light-emitting diode irradiation was found.     

A study of the effect of low-intensity laser radiation of the blue, green, and red spectral regions on the healing of experimental skin wounds in rats

The effect of low-intensity laser radiation of the blue (441.2 nm), green (532 nm), and red (632.8 nm) spectral regions on the healing of experimental skin wounds in rats has been studied. The effect of the traditionally applied laser radiation in the red region has been compared with the effect of laser radiation in the other spectral regions, assuming that, upon irradiation of wounds by lasers emitting in the blue and green regions, a similar effect can be achieved at lower doses. The following parameters characterizing the healing of experimental wounds were used: the functional activity of phagocytes of wound exudates, which was determined by luminol-dependent chemiluminescence, and their number; the antioxidant activity of wound exudates; and the rate of healing, which was determined as a change in the wound area. It was shown that irradiation with laser accelerated the healing of wounds in all cases. The exposure to laser radiations in the red (1.5 J/cm), blue, and green (0.75 J/cm2) spectral regions shortened the time of wound healing from 22 to 17 and 19 days, respectively. The functional activity of leukocytes after the exposure increased on day 5 after the infliction of the wound, whereas in the control it decreased. The superoxide dismutase activity increased in all experimental groups by day 5 after the operation. A maximum increase in the superoxide dismutase activity occurred after the exposure to laser radiation in the red region at a dose of 1.5 J/cm and in the blue and green spectral regions at a dose of 0.75 J/cm2.     

A comparative study of the effects of laser and LED radiation on lipid peroxidation in rat wound fluid

The effect of laser (632 nm) and LED (630 nm) on lipid peroxidation in rat wound fluid (exudate) was studied with the aim of comparing the efficiency of coherent and incoherent light on the processes that take place during wound healing. The study was performed using the model of cut aseptic wounds proposed by L.I. Slutskii. It was shown that irradiation of wounds with light of both laser and LED caused a decrease in the concentration of lipid peroxidation products in wound fluid as compared with the control group. An increase in the antioxidative activity of wound fluid was observed. It was concluded that irradiation with light of both laser and LED decreases the level of oxidative stress in wound fluid and that radiation coherence does not play a significant role.     

A comparative study of the effects of laser and light-emitting diode irradiation on the wound healing and functional activity of wound exudate leukocytes

The effects of coherent He-Ne laser and non-coherent light-emitting diode radiation on rat skin wound healing and functional activity of wound excudate leukocytes were compared. A comparative pathomorphological analysis showed that the He-Ne laser and light-emitting diode irradiation stimulated the transition of the inflammatory phase of the wound healing into the reparative (proliferative) and scarring phases sequentially. It was also detected that the functional activity of leucocytes changed in a dose-dependent manner. The leukocyte activity was found to be similar in the groups with laser and light-emitting diode irradiation. Thus, we can conclude that coherent laser and non-coherent light-emitting diode radiation have very close effects on wound healing and activity of wound exudate leukocytes, and coherence is not required for this activity.     

The effect of low-intensity laser irradiation in the blue, green, and red spectral ranges on healing of experimental skin wounds in rats

The effects of low-intensity laser irradiation in the red (632.8 nm), green (532 nm), and blue (441.2 nm) spectral ranges on wound healing has been studied in rats. The effect of the traditionally used red laser irradiation has been compared with the effect caused by laser irradiation in other spectral ranges, aiming to support the provisional hypothesis that a similar healing effect could be achieved at lower doses of wound irradiation by lasers emitting in the blue and green spectral ranges. The following parameters have been used to characterize healing of the experimental wounds: the functional activity of phagocytes in the wound exudate, which was determined from luminol-dependent chemiluminescence, the phagocyte number; the wound exudates’ antioxidant activity; and the rate of healing, which was determined as the change of the wound surface area. It was found that in all cases the laser irradiation accelerated the healing of wounds. Exposure to red laser irradiation at the dose of 1.5 J/cm²), and to blue or green laser irradiation at a dose of 0.75 J/cm² shortened the time of the wound healing from 22 to 17 and 19 days, respectively. The functional activity of leukocytes in irradiated groups increased by day 5 after surgery, whereas in the control group it decreased. The superoxide dismutase activity increased in all experimental groups by day 5 after surgery. Laser irradiation in the red spectral range at a dose of 1.5 J/cm² resulted in a larger increase in superoxide dismutase activity, as compared to that found after exposure to laser irradiation in the blue and green spectral ranges at a dose of 0.75 J/cm².     

The role of endogenous porphyrins in laser therapy of experimental skin wounds

The role of endogenous porphyrins in the effect of laser irradiation on the superoxide dismutase (SOD) activity of wound exudate and rat leukocyte activity has been studied on models of aseptic incised skin wounds. Wounds were irradiated with a He-Ne laser (632.8 nm, 1.5 J/cm²) on the 2nd, 3rd, and 4th days after the beginning of the experiment. Irradiation effects were evaluated by the SOD activity (NBT test) and the activity of leukocytes of the wound exudate (as a chemiluminescent response to opsonized zymosan). It was found that in animals subjected to laser irradiation, the SOD activity sharply increased. This effect depended on endogenous porphyrin concentration and was retained throughout the experiment. The SOD activity in unirradiated animals decreased from the 2nd to the 5th day of experiment. The evaluation of the activity of wound exudate leukocytes did not reveal any distinct dependence of the effect on the concentration of endogenous porphyrins.     

Role of endogenous porphyrins in the effects of low-intensity laser radiation of the red region on free radical processes in the blood of rats under experimental endotoxic shock

The role of endogenous porphyrins in the effects of laser radiation of the red region (632.8 nm) on free radical processes in the blood of rats under endotoxic shock induced by the administration of lipopolysaccharide B (25 mg/kg) has been studied. The measurements of the functional activity of polymorphonuclear leukocytes (the method of luminol-dependent chemiluminescence), the superoxide dismutase activity of blood plasma (using nitro blue tetrazolium), and the degree of lipid oxidation of erythrocyte membranes (the method of fluorescence of cis-parinaric acid) have been carried out. It has been found that low-intensity laser radiation strongly affects all processes examined irrespective of the administration of lipopolysaccharide B. The effect of radiation was most pronounced in animals injected with the polysaccharide, the changes being dependent on the concentration of endogenous porphyrins in samples.     

Role of endogenous porphyrins in the effects of low-intensity laser radiation of the red region on free radical processes in the blood of rats under experimental endotoxic shock

The role of endogenous porphyrins in the effects of laser radiation of the red region (632.8 nm) on free radical processes in the blood of rats under endotoxic shock induced by the administration of lipopolysaccharide B (25 mg/kg) has been studied. The measurements of the functional activity of polymorphonuclear leukocytes (the method of luminol-dependent chemiluminescence), the superoxide dismutase activity of blood plasma (using nitro blue tetrazolium), and the degree of lipid oxidation of erythrocyte membranes (the method of fluorescence of cis-parinaric acid) have been carried out. It has been found that low-intensity laser radiation strongly affects all processes examined irrespective of the administration of lipopolysaccha-ride B. The effect of radiation was most pronounced in animals injected with the polysaccharide, the changes being dependent on the concentration of endogenous porphyrins in samples.     

Evidence for manganese(III) binding to the mangano superoxide dismutase from a higher plant (Pisum sativum L.)

Homogenous preparations of a manganese superoxide dismutase from a higher plant (Pisum sativum L.) were studied by epr and optical spectroscopies. The visible spectrum of manganese superoxide dismutase shows a weak and broad band in the range 350–700 nm with two shoulders at about 480 and 600 nm. Reduction with dithionite brought about a considerable disappearance of the visible component of the spectrum. The epr spectra of the native and dithionite-treated enzyme did not show any signal attributable to Mn(II) that only was visible after acid hydrolysis of the protein. The lack of epr signal both in the native and reduced superoxide dismutase can be attributed to the presence of Mn(III) in the former and of Mn(II) strongly bound to the protein in the latter. The results obtained with the manganese superoxide dismutase from leaves of the higher plant Pisum sativum are consistent with the general catalytic mechanism of action postulated for superoxide dismutases from other sources studied so far.     

Changes in Superoxide Dismutase Activity and Peroxynitrite Content in Rat Peritoneal Macrophages Exposed to He-Ne Laser Radiation

The formation of reactive oxygen and nitrogen species by rat peritoneal macrophages induced by a low-intensity He-Ne laser radiation (LR) was studied in this work. It was found that the formation of reactive oxygen species, nitric oxide, and peroxynitrite as well as changes in the activity of superoxide dismutase (SOD) depended to a large extent on the LR dose. In particular, it was found that activation of SOD at low LR doses was accompanied by nitric oxide level increase, while the level of peroxynitrite showed no significant changes. On the other hand, an enhanced LR dose inhibited the enzyme, and this was accompanied by peroxynitrite accumulation. All the measurements were carried out the day after LR treatment. The revealed regularities consequently demonstrate the existence of a deferred LR action on macrophages associated with the production of reactive oxygen and nitrogen species.     

A study of the functional activity of macrophages of peritoneal exudate of mice exposed to low-intensity laser radiation in vitro and in vivo

The effect of low-intensity laser radiation generated by semiconductor devices in the red (650 nm) and infrared (850 nm) regions of the spectrum in vitro and in vivo on the phagocytic activity and synthesis of proinflammatory cytokines by peritoneal macrophages during the phagocytosis of bacterial cells has been studied. A culture of the clinical strain of the enteropathogenic bacterium Escherichia coli was used as an object. The radiation dose was varied by changing the power and duration of exposure. The results obtained indicate that infrared low-intensity laser radiation has a stimulating effect on the phagocytic activity of macrophages. It was shown that the effect of low-intensity laser radiation on the activity of the phagocytic process, the enhancement of the adhesion of bacteria by macrophages, killing of bacteria, and the production of proinflammatory cytokines is dose-dependent. The exposure to the rays of the red region of the spectrum on phagocytizing macrophages induced a decrease in their activity; as the dose was increased, the destruction of cells was registered.     

Combination of an engineered Lactococcus lactis expressing CXCL12 with light-emitting diode yellow light as a treatment for scalded skin in mice

Impaired wound closure is an increasingly crucial clinical challenge. Recently, wound healing has shifted towards innovative treatments that exploit nanotechnology, biomaterials, biologics and phototherapy. Here, we constructed an engineered MG1363-pMG36e-mCXCL12 strain with pMG36e plasmid encoding stromal cell-derived factor 1α (named CXCL12) and evaluated the synergistic effects of light-emitting diode (LED) yellow light and MG1363-pMG36e-mCXCL12 on scald wounds in mice. The results indicated that the combined treatment with LED yellow light with mCXCL12 delivering strain accelerated wound closure, tissue remodelling, re-epithelialization and hair follicle regeneration and inhibited over-inflammation oppositely in the central and surrounding wounds by macroscopic, histopathologic and immunohistochemistry parameters. Furthermore, combination therapy increased the epidermal growth factor and Ki67-positive cells and upregulated beta-catenin (β-catenin), cellular-myelocytomatosis (c-Myc), wingless-type MMTV integration site family member 1 (Wnt1), Jagged 1, neurogenic locus notch homolog protein 1 (Notch 1) and hairy and enhancer of split 1 (Hes 1) protein levels of the Wnt and Notch signalling pathways. It also facilitated collagen fibrogenesis and deposition and improved the activities of hydroxyproline, superoxide dismutase and glutathione peroxidase in scalded granulation tissue, in addition to reducing the inflammatory factors interleukin 1 beta (IL-1β) and tumour necrosis factor alpha (TNF-α). The combined treatment effectively reduced skin pathogens Ralstonia and Acinetobacter to further reduce the risk of infection. Overall, combination of LED yellow light and MG1363-pMG36e-mCXCL12 represents a potential strategy for the treatment of cutaneous wounds.     

State of anti- and pro-oxidative systems during the healing of aseptic and infected wounds in animal experiments

Time-course changes in the specific activity of superoxide dismutase (SOD) and hydroperoxides were studied in granulation tissue and blood serum of 230 Wistar male rats weighing 200-210 g with simulated aseptic and infected surface wounds before and 1-10, 12, 15 days after the operation. Differences in the level range of SOD and hydroperoxides specific activity were demonstrated in tissues and sera. The dependence of hydroperoxide levels on the wound stage, as well as the dependence of SOD specific activity time-course on the character and severity of wound were stated. The allowances should be made of those differences in the shifts observed in anti- and pro-oxidative systems during wound healing when corrective therapeutic measures are considered.     

The effect of low power laser radiation of blue,green, and red ranges on free radical processes in blood of rats with experimental endotoxic shock

This study was performed to investigate the effects of low power laser radiation in blue (441.2 nm), green (532.5 nm) and red (632.8 nm) wavelength ranges on free radical processes in experimental endotoxic shock in rats. The experimental model was induced by intraperitoneal injection of lipopolysaccharide B (25 mg/kg) (LPS). Functional activity of blood leukocytes was evaluated by the method of luminol-dependent chemiluminescence, plasma superoxide dismutase activity was determined by the nitro blue tetrazolium assay, intensity of lipid peroxidation in erythrocyte membranes was estimated by cis-parinaric acid fluorescence. It was found that the low power laser radiation significantly influenced all investigated processes, in LPS-treated and control animals. The most pronounced effects were observed in all groups of LPS-treated animals, in which the laser radiation increased all investigated parameters. At the radiation dose 0.75 J/cm² green laser was the most effective, while at the dose of 1.5 J/cm² both green and red lasers produced potent effects. Possible mechanisms of the observed phenomena are discussed.     

The bactericidal effect of ultraviolet and visible light on Escherichia coli

The bactericidal radiation dosages at specific wavelengths in the ultraviolet (UV)-visible spectrum are not well documented. Such information is important for the development of new monochromatic bactericidal devices to be operated at different wavelengths. In this study, radiation dosages required to cause mortality of an Escherichia coli strain, ATCC 25922, at various wavelengths between 250 and 532 nm in the UV and visible spectrum were determined. Radiation at 265 nm in the UV region was most efficient in killing the E. coli cells and 100% mortality was achieved at a dose of 1.17 log mJ/cm(2). In the visible spectrum, the radiation dosages required for a one-log reduction of the E. coli cell density at 458 and 488 nm were 5.5 and 6.9 log mJ/cm(2), respectively. However, at 515 and 532 nm, significant killing was not observed at radiation dosage up to 7 log mJ/cm(2). Based on the cell survival data at various radiation dosages between 250 and 488 nm, a predictive equation for the survival of E. coli cells is derived, namely log(S/S(0)) = -(1.089 x 10(7) e(-0.0633lambda))D. The symbols, S(0), S, lambda, and D, represent initial cell density, cell density after irradiation, wavelength of the radiation and radiation dosage, respectively. The proportion of the surviving E. coli cells decreases exponentially with the increase in radiation dosage at a given wavelength. In addition, the radiation dose required for killing a certain fraction of the E. coli cells increases exponentially as the wavelength of radiation increases.     

Oxyradicals and PSII activity in maize leaves in the absence of UV components of solar spectrum

The regulation of oxyradicals and PSII activity by UV-B (280-315 nm) and UV-A (315-400 nm) components were investigated in the leaves of maize [Zea mays L. var: HQPM.1]. The impact of ambient UV radiation on the production of superoxide (O2-) and hydroxyl (.OH) radicals were analysed in the leaves of 20-day-old plants. The amount of O2.- and .OH radicals and the radical scavenging activity were significantly higher in the leaves exposed to ambient UV radiation as compared to the leaves of the plants grown under UV exclusion filters. Smaller amount of oxyradicals in the leaves of UV excluded plants was accompanied by a substantial increase in quantum yield of electron transport (phi Eo), rate of electron transport (psi o) and performance index (PIABS), as indicated by chlorophyll a fluorescence transient. Although higher amounts of oxyradicals invoked higher activity of antioxidant enzymes like superoxide dismutase and peroxidase under ambient UV, they also imposed limitation on the photosynthetic efficiency of PSII. Exclusion of UV components (UV-B 280-315 nm; UV-A 315-400 nm) translated to enhanced photosynthesis, growth and biomass. Thus, solar UV components, especially in the tropical region, could be a major limiting factor in the photosynthetic efficiency of the crop plants.     

Spectroscopic evidence for the generation of singlet oxygen in the reduced nicotinamide adenine dinucleotide phosphate-dependent microsomal lipid peroxidation system.

In the presence of Fe3+-ADP and NADPH, washed rat liver microsomes at 37 degrees and at pH 7.5 emitted ultraweak light with the peroxidative cleavage of endogenous lipid. The main light-emitting species of this system was analyzed spectroscopically in the visible region and estimated to be singlet oxygen. The addition of superoxide dismutase or catalase did not inhibit the light emission significantly. It is unlikely therefore that superoxide anion and OH are involved in the generation of singlet oxygen in the present system.     

UV-B辐射对蚕豆叶膜脂过氧化的影响及其机制

温室种植的吞豆在0（CK）,8．82kJ/m2(T1)和12．6kJ/m2(T2)3种剂量的紫外线B（UV－B）辐射引起膜脂变化及其机制的研究结果表明,UV0B处理后,蚕豆叶片中丙二醛（MDA）和H2O2含量升高,膜脂肪酸不饱和度指数（IUFA）降低,脂氧合酶（LOX）活性升高,超氧歧化酶（SOD）活性稍有波动,而3种多胺－腐胺（Put)精胺（Spd)和尸胺（Spn)在照射7天后均有积累,但在处理后期（21d)有所回落,推测由LOX主导的酶促膜过氧化作用和氧自由基引起的非酶促过作用在膜结构的破坏中起重要作用,SOD活性和多胺含量的变化蚕豆对UV－B胁迫的一种适应性生理反应。