Low-level Laser Irradiation Research Articles

Effect of low-level laser intervention on dermatitis symptoms and cytokine changes in DNCB-induced atopy mouse model: A randomized controlled trial.

The incidence of atopic dermatitis (AD) has recently increased due to various factors. Its prevalence is higher among children and teenagers than in other age groups. Numerous methods to treat AD are available, including light ray therapy, which has been proposed as an alternative therapy for the treatment of AD. The present study aimed to evaluate the curative mechanism and optimal energy level of energy irradiation from a low-level laser (LLL) toward AD. AD was induced in BALB/c mice with dinitrochlorobenzene (DNCB) solution. The mice were divided into six groups, including one normal control (n=8), one AD control (n=10) and four AD experimental groups with LLL irradiation at 2 J/cm2 (n=10), 4 J/cm2 (n=10), 6 J/cm2 (n=9) and 8 J/cm2 (n=10). Following AD induction, an LLL was applied to the four AD experimental groups for 2, 4, 6, and 8 min, for two weeks (14 times in total) at a wavelength of 650 nm and an output of 50 mW. The effects of irradiation on AD were evaluated using a scratch test, a clinical skin severity test, immunoglobulin-E (IgE) analysis and measurements of numerous cytokine levels, including interleukin (IL)-4, IL-6, tumor necrosis factor (TNF)-α, and interferon-γ (IFN-γ), tissue thickness and mast cell count. The results demonstrated that serum IgE level in all irradiated groups was significantly decreased compared with that of the AD control group, and IL-4 level was significantly decreased in all irradiated groups apart from the 8 J/cm2 LLL irradiated group. IL-6 and TNF-α levels were also significantly decreased in all irradiated groups. The results from histological analysis revealed diminished epidermal thickness and mast cell counts in irradiated mice compared with those mice in the AD control group. In summary, these findings suggested that LLL irradiation may alleviate symptoms of AD and may be useful for restoring cytokines levels and tissues features to normal levels.

High-frequency near-infrared diode laser irradiation suppresses IL-1β-induced inflammatory cytokine expression and NF-κB signaling pathways in human primary chondrocytes.

Osteoarthritis (OA) and rheumatoid arthritis (RA) are common inflammation-associated cartilage degenerative diseases. Recent studies have shown that low-level diode laser treatment can reduce inflammatory cytokine expressions in cartilage. We recently reported that high-frequency low-level diode laser irradiation attenuates matrix metalloproteinases (MMPs) expression in human primary chondrocytes. However, the molecular mechanism underlying the effect of high-frequency low-level diode laser on chondrocytes remains unclear. Therefore, we aimed to elucidate the effect of high-frequency low-level diode laser irradiation on inflammatory cytokine expression in human primary chondrocytes. Normal human articular chondrocytes were treated with recombinant interleukin-1 beta (IL-1β) for 30min or 24h and irradiated with a high-frequency NIR diode laser at 8J/cm2. The expression of IL-1β, interleukin-6, and tumor necrosis factor-alpha was assessed using western blot analysis. To evaluate the nuclear factor-kappa B (NF-κB) signaling pathway, the phosphorylation, translocation, and DNA-binding activity of NF-κB were detected using western blot analysis, immunofluorescence analysis, electrophoretic mobility shift assay, and enzyme-linked immunosorbent assay analysis. High-frequency low-level diode laser irradiation decreased inflammatory cytokine expression in IL-1β-treated chondrocytes. Moreover, high-frequency low-level diode laser irradiation decreased the phosphorylation, nuclear translocation, and DNA-binding activity of NF-κB in the IL-1β-treated state. However, irradiation alone did not affect NF-κB activity. Thus, high-frequency low-level diode laser irradiation at 8J/cm2 can reduce inflammatory cytokine expressions in normal human articular chondrocytes through NF-κB regulation. These findings indicate that high-frequency low-level diode laser irradiation may reduce the expression of inflammatory cytokines in OA and RA.

Effect of Low-Level Laser Irradiation on Accommodation and Visual Fatigue.

PurposeThis study used low-level laser irradiation on auricular points for the eyes of junior college teenagers with myopia to observe the changes in refractive errors and eye accommodation. According to the Sterner’s study, we used the relationship between the amplitude and subjective symptoms to assess the degree of improvement in visual fatigue caused by changes in accommodation.MethodsParticipants were 49 healthy junior college teenagers, with an average age of 16.04±0.80 years old, and the refractive errors of both eyes were between −1.50 D and −5.00 D. All participants underwent refractive error tests before and after class and after a 30-min break. In a 30-min break, all participants underwent two tests of with (experimental group) and without (control group) low-level laser irradiation on the auricular points. Then, refractive error tests were conducted to evaluate the participants’ eye accommodation.ResultsThe results revealed that with treatment of the auricular points with and without low-level laser irradiation, the refractive error of the participants’ binocular left and right eyes decreased by −0.12 D (−0.18 D) in the experimental grou and by −0.05 D (−0.02D) in the control group. For the amplitudes of accommodation (AA) examination, the AA of the participants’ binocular in the experimental group became 7.98 ± 1.35 D (7.65 ± 1.37 D). The AA of participants’ binocular can recover to the level before the class.ConclusionThe results indicated that low-level laser irradiation at auricular points restored the eye accommodation faster than did natural closing of the eyes.

Benefits of Sebastiania hispida (Euphorbiaceae) extract and photobiomodulation therapy as potentially adjunctive strategies to be explored against snake envenoming.

The purpose of this study was to assess the topic use of Sebastiania hispida extract and low-level gallium-arsenide laser irradiation (GaAs, 904nm) to reduce the local myonecrosis and edema of Bothrops moojeni snake venom-injected gastrocnemius. Wistar rats receiving intramuscular venom injection (VBm) were compared with saline control (S) and envenomed rats receiving local exposure to plant extract (VExt) or laser irradiation (VL). The phytochemistry and thin-layer chromatography of S. hispida extract indicated the presence of phenolic compounds like gallic acid and flavonoids including quercetin. Gastrocnemius of VExt and VL groups had a significant reduction of edema and creatine kinase (CK) activities and a greater Myogenin (MyoG) expression compared to VBm group, with the plant extract efficacy better than laser exposure. Reduction of edema and serum CK activities reflects a lessening of muscle damage, whereas the increase of MyoG indicates myoblast differentiation and acceleration of muscle repair. The S. hispida richness in phenolic compounds and flavonoids, such as the light modulatory ability to triggering a multitude of cell signalings likely underlie the positive outcomes. Our findings suggest both treatments as potential auxiliary tools to be explored in clinical trials in combination with anti-venom therapy after Bothropic snakebites.

Fractionated low-level laser irradiation on breast cancer (MCF 7 cells) treatment.

Breast cancer is responsible for one of the top leading causes of cancer deaths among women. Radiotherapy (RT) uses high energy radiation to kill cancer cells, but this method has been reportedly linked to risks of toxicity. Post-therapeutic relapse from RT believed to be caused by its toxicity is one of the challenges encountered during tumour therapy. Therefore, further attention should be devoted to developing novel anti-tumour therapeutic approaches. The role of low-level laser therapy (LLLT) in breast cancer management is to alleviate the side effects arising from RT, instead of acting against the tumour cells directly. This study investigated the effects of low-level laser (532nm), as well as single and fractionated irradiation, on breast cancer MCF 7 cell line. Additionally, this study assessed the most effective laser parameter for fractionated irradiation. The MCF 7 cells were irradiated with green laser power at 1.5, 45.0, and 100.0 mW with a spot size diameter of 0.7mm for 1, 5, 10, and 15min. The irradiation was carried out in single, double, and triple fractionation separated by 5- and 10-min intervals in between the fractional regimes. The laser output of 100 mW showed a promising potential in killing cells with single fractionation. However, as the irradiation was fractionated into two, power of 1.5 mW appeared to be more effective in cell death, which contributed to the lowest percentage cells viable of 31.4% recorded in the study. It was proven that fractionated regime was more successful in tumour cell death.

Low-Level Erbium-Doped Yttrium Aluminum Garnet Laser Irradiation Induced Alteration of Gene Expression in Osteogenic Cells from Rat Calvariae.

Objective: The aim of this study was to investigate the effect of low-level erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation on gene expression in osteogenic cells from rat calvariae. Background: Previous studies showed beneficial effects of laser irradiation on bone-related cells. However, few studies have examined the gene expression alteration by laser irradiation on osteogenic cells in a calcified condition. Materials and methods: Osteogenic cells were prepared by culturing rat calvarial osteoblast-like cells in osteoinductive medium for 21 days. The cells at the bottom of the culture dish were irradiated with Er:YAG laser (wavelength: 2.94 μm, energy density: 3.1 and 8.2 J/cm2) positioned at distance of 25 cm. Lactate dehydrogenase (LDH) assay of the irradiated cells was performed. After screening for genes related to bone formation, mechanotransduction, and thermal effect by quantitative polymerase chain reaction (qPCR), gene expression at 3 h after 3.1 J/cm2 irradiation was comprehensively analyzed using microarray. Results: No dramatical increase in surface temperature and LDH activities after laser irradiation were observed. Sost expression was significantly reduced at 3 h after 3.1 J/cm2 irradiation. Bcar1 and Hspa1a expression was significantly increased following 8.2 J/cm2 irradiation. Microarray analysis identified 116 differentially expressed genes. Gene set enrichment analysis showed enrichment of histone H3-K9 methylation and modification gene sets. Conclusions: Er:YAG laser irradiation, especially at 3.1 J/cm2, showed positive effect on the expression of genes related to bone formation in osteogenic cells, without inducing significant cell damage. These findings may represent critical mechanisms of early bone formation after Er:YAG laser irradiation.

Low-level laser irradiation enhances the proliferation and osteogenic differentiation of PDLSCs via BMP signaling

The aim of this in vitro study was to evaluate the effects of low-level laser therapy (LLLT) at different energy intensities on proliferation and osteogenesis of periodontal ligament stem cells (PDLSCs). We designed one control group, without irradiation and four testing groups, treated with LLLT (Nd:YAG;1064nm) at 2, 4, 6, and 8J/cm2 for human PDLSCs. Cell proliferation was measured using colony-forming unit fibroblast assay and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay. Osteogenic capacity of cells was determined by alkaline phosphatase (ALP) staining, ALP activity assay, Alizarin Red S staining, and the gene levels of runt-related transcription factor 2 (Runx2), ALP, osteocalcin, and bone morphogenetic protein 2 (BMP2). The effects of LLLT on secretion of TNF-α and IL-1β in PDLSCs were measured by enzyme-linked immunosorbent assay. BMP/Smad pathway was measured through the expression of Smad1/5/8 phosphorylation (P-Smad1/5/8). LDN-193189, an inhibitor of the BMP/Smad pathway, was used to explore the underlying effects of BMP/Smad signaling on the process of LLLT regulating the proliferation and osteogenesis of PDLSCs. Our results demonstrated LLLT could promote the proliferation and osteogenesis of PDLSCs at 2-6J/cm2 and LLLT at 8J/cm2 significantly suppress osteogenic differentiation of PDLSCs. Moreover, LLLT stimulated the secretion of TNFα and IL-β1. Finally, we found the irradiation positively modulates the P-Smad1/5/8 level. When the cells were treated with LDN-193189, the proliferation and osteogenic effects of LLLT on PDLSCs were attenuated. In conclusion, LLLT may upregulate the proliferation and bone formation ability of PDLSCs via the BMP/Smad signaling.

Combination effect of red light irradiation and Traychspermum ammi essential oil on colorectal cancer cells (SW480).

Colon cancer is the third significant reason for death related to cancers in the world. There are various treatments for colon cancer, which have several side effects. Polyphenol agents are a type of antioxidant in plants that have diverse biological properties, such as anti-cancer effects. Here, we investigate the effect of Trachyspermum ammi essential oil (TEO) and red light irradiation on the colorectal cancer cell line (SW 480). The colorectal cancer cell lines were irradiated at 660nm for 90s and then the cells were incubated with different TEO concentrations. In another study, cells initially were treated with various TEO concentrations and then irradiation for 90s. Effect of TEO and the red light irradiation on viability of the cell, ROS generation, and cell cycle was assessed by MTT and flow cytometry, respectively. The findings demonstrated that early incubation with TEO and then irradiation decreased the SW 480 cells survival more than the early irradiation at 660nm and then essential oil. In addition, TEO treatment at IC50 concentration in combination with low-level laser irradiation induces ROS generation in SW 480 cells as compared to the dark group. In addition, TEO treatment at IC50 in combination with low-level laser irradiation induces G0/G1 arrest of the cell cycle in SW 480 cells in comparison to the dark group. This study revealed that the Trachyspermum ammi essential oil in combination with low-level laser results in more reduction in survival which leads to ROS generation and cell cycle arrest in SW 480 colorectal cancer cells.

Photobiomodulation with Red and Near-Infrared Light Improves Viability and Modulates Expression of Mesenchymal and Apoptotic-Related Markers in Human Gingival Fibroblasts.

Photobiomodulation (PBM), also called low-level laser treatment (LLLT), has been considered a promising tool in periodontal treatment due to its anti-inflammatory and wound healing properties. However, photobiomodulation’s effectiveness depends on a combination of parameters, such as energy density, the duration and frequency of the irradiation sessions, and wavelength, which has been shown to play a key role in laser-tissue interaction. The objective of the study was to compare the in vitro effects of two different wavelengths—635 nm and 808 nm—on the human primary gingival fibroblasts in terms of viability, oxidative stress, inflammation markers, and specific gene expression during the four treatment sessions at power and energy density widely used in dental practice (100 mW, 4 J/cm2). PBM with both 635 and 808 nm at 4 J/cm2 increased the cell number, modulated extracellular oxidative stress and inflammation markers and decreased the susceptibility of human primary gingival fibroblasts to apoptosis through the downregulation of apoptotic-related genes (P53, CASP9, BAX). Moreover, modulation of mesenchymal markers expression (CD90, CD105) can reflect the possible changes in the differentiation status of irradiated fibroblasts. The most pronounced results were observed following the third irradiation session. They should be considered for the possible optimization of existing low-level laser irradiation protocols used in periodontal therapies.

EFFECTS OF LOW-LEVEL LASER IRRADIATION ON THE GROWTH OF THE RAT MANDIBULAR CONDYLE IN ORGAN CULTURE

<h3>Objective</h3> The present study was carried out to histologically, immunohistochemically, and histometrically investigate the effect of low-level laser irradiation by a diode laser on the growth of the rat mandibular condyle in organ culture. <h3>Methods</h3> The mandibular condyles were removed from rats' embryos on the 21st day and then cultured for 8 days. The 20 cultured condyles were divided into 4 groups: F−L− group (serumless BGJb); F+L− group (serumless BGJb with bFGF 100 ng/mL); F−L+ group (serumless BGJb and laser irradiation); and F+L+ group (serumless BGJb with bFGF 100 ng/mL and laser irradiation). The laser irradiation (output 1.3 W/cm² and wavelength 633 nm) was performed on the cultured condyle for 30 seconds every 24 hours for 5 days. Immunohistochemically, PCNA was used to analyze cell proliferation. <h3>Results</h3> The mesenchymal cells in the layer of differentiation and hypertrophy in the F+L+ group showed a marked increase in cell number and the size of the condyle. The positive cell number of PCNA in F+L− and F+L+ group was significantly higher compared with the control group. <h3>Conclusions</h3> Our data showed that low-level laser irradiation promotes cell proliferation in the cultured condyle same as in bFGF addition. It is suggested that low-level laser irradiation by a diode laser (wavelength 633 nm) stimulated the proliferation of mesenchymal cells, which resulted in an increase in the number of chondrocytes in the layers of differentiation and hypertrophy by leading to the enlargement of the condylar size.

Low-Level Laser Irradiation Stimulates RANKL-Induced Osteoclastogenesis via the MAPK Pathway in RAW 264.7 Cells

Low-level laser therapy (LLLT) is recognized as an effective medical tool for the treatment of various conditions requiring tissue repair, pain relief, inflammation treatment, and restoration of tissue dysfunction, and its development and research are growing rapidly. However, studies that analyze molecular biology by applying LLLT to osteoclasts are still insufficient to understand the mechanism. In order for LLLT to be suggested as an appropriate treatment method for the treatment of various bone diseases, it is necessary to elucidate the effect and mechanism of LLLT on osteoclast differentiation. In this study, we investigated the effect of LLLT on osteoclast differentiation using murine macrophage (RAW 264.7) cells by means of a Ga-As-Al laser (λ = 810, 80 mW). Our results indicate that LLLT did not induce cytotoxicity in RAW 264.7 cells. When LLLT was applied for 15 s to osteoclasts exposed to RANKL, the expression of NF-κB, ERK, p38, and c-Fos, which are associated with expression of NFATc1, was increased. The RT-PCR results also demonstrated significantly increased expression of osteoclast-specific genes, including NFATc1, TRAP, the calcitonin receptor, and cathepsin K, compared with the control. Taken together, we concluded that low-level laser irradiation induces osteoclastogenesis by enhancing the expression of NF-κB, MAPKs (ERK, p38), c-Fos, and NFATc1 in RAW 264.7 cells. These findings indicate that low-level laser irradiation could be considered a potential treatment option in various metabolic bone diseases that require osteoclastic activity and bone formation.

PPARγ gene expression analysis in psoriasis treatment

Introduction. PPARγ is the most studied PPAR subtype and is expressed predominantly in adipose tissue, heart, colon, kidney, spleen, intestine, skeletal muscle, liver, macrophages, and skin. In the skin, PPARγ controls the genetic regulation of gene network expression involved in cell proliferation, differentiation, and inflammatory responses. PPARγ (Peroxisome proliferator-activated receptor gamma) has only recently come to be considered a key player in the development and pathogenesis of psoriasis and psoriatic inflammatory conditions.Aim of the study. To study PPARγ gene expression in the affected skin of psoriasis patients in comparison with visually unaffected skin. To study changes in PPARγ gene expression level in psoriasis affected skin in comparison with unaffected skin in patients before and after treatment with low-level laser radiation with a wavelength of 1.27 μm.Materials and methods. Twelve patients with psoriasis participated in the study. Biopsies from unaffected skin areas were taken at a distance of about 3 cm from the affected skin. Analysis was performed by real-time PCR.Results and Discussion. We quantitatively measured PPARγ gene expression using RT-PCR in the affected skin of patients with psoriasis in comparison with visually unaffected skin in the same patients before and after treatment with low-level laser radiation with a wavelength of 1.27 μm (the short-wave part of the infrared range). The study experimentally showed a 1.3 ± 0.27-fold decrease in PPARγ gene expression in the affected skin of psoriasis patients on average. Significant increase in over-expression of PPARγ gene up to 2,13 ± 0,47 times was observed after treatment of patients with low-level laser radiation.Conclusions. PPARγ gene expression may be an indicator of the efficacy of psoriasis treatment at the molecular level, as well as become a new therapeutic target.

Protective effect of low-level laser irradiation on lipopolysaccharide-mediated inflammatory injury of human periodontal ligament fibroblasts.

To study the effect and mechanism of low-level laser irradiation (LLLI) on lipopolysaccharide (LPS)-induced inflammatory injury of human periodontal ligament fibroblasts (hPDLFs). hPDLFs were inoculated into well plates and randomly divided into the normal group, LPS group, and LPS+LLLI group. The cells in the normal group were cultured in conventional medium. The hPDLFs in the LPS and LPS+LLLI groups were cultured in RPMI1640 medium containing 1 mg·L-1 LPS. The three subgroups of the LPS+LLLI group were exposed to different LLLI. After 4 days, the cell apoptosis, viability, and intracellular free Ca2+ concentration of each group were measured. The contents of tumor necrosis factor-α (TNF-α), interleukin (IL)-8, IL-1β, and IL-6 were measured by enzyme linked immunosorbent assay (ELISA). Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the expression of matrix metalloproteinase (MMP)-2, MMP-3, and MMP-9 genes and proteins of hPDLFs in each group. Compared with the normal group, the LPS group showed increased apoptosis rate of hPDLFs and intracellular free Ca2+concentration and decreased cell viability (P<0.05). The TNF-α, IL-8, IL-1β, and IL-6 levels were higher in the cell supernatant (P<0.05), and the expression of MMP-2, MMP-3, and MMP-9 genes and proteins of hPDLFs was significantly increased (P<0.05). Compared with the LPS group, the LPS+LLLI group showed significantly decreased apoptosis rate and intracellular free Ca2+ concentration and significantly increased cell viability (P<0.05). The TNF-α, IL-8, IL-1β, and IL-6 levels in the supernatant of cells and the expression of MMP-2, MMP-3, and MMP-9 genes and proteins of hPDLFs were significantly decreased (P<0.05). LLLI has a protective effect on the inflammatory injury of hPDLFs induced by LPS, and the effect is most obvious when the irradiation intensity is 4 J·cm-2.

Therapeutic Window of Photodynamic Treatment (PDT) in Conservative Periodontal Therapy -Analysis of Cell Migration Within A Three Dimensional Collagen Matrix-

Objectives: The aim of the present study was to investigate the effect of low-level laser irradiation as photodynamic therapy (PDT) on proliferation and differentiation of a human fibroblast cell line, determining the therapeutic window of toluidine blue O (TBO) using the 3-D collagen matrix assay with fibroblasts.

Efficacy of Minoxidil Combined With Photobiomodulation for the Treatment of Male Androgenetic Alopecia. A Double-Blind Half-Head Controlled Trial.

Androgenetic alopecia (AGA) is a hair loss disorder that frequently affects the male population. Conventional treatment modalities are limited to minoxidil, 5α reductase inhibitors, and hair transplantation procedures. The efficacy of low-level laser therapy (LLLT), also known as photobiomodulation, in the treatment of AGA has been reported, yet little is known about the outcomes of combining photobiomodulation with other conventional therapies. To evaluate hair growth improvement in males with AGA, during the administration of minoxidil with and without photobiomodulation, using a half-head model. Twenty-one men with AGA agreed to undergo 12 minutes of low-level laser irradiation (using a modified Capellux®), followed by topical minoxidil application (1 mlof 5% solution), to the affected scalp two times per day for 6 months. The photobiomodulation devices were modified such that the left half emitted light, and the right half did not. Efficacy was assessed by blinded analyses of clinical photos and automated phototrichograms (Trichoscan®) taken before treatment and after 3 and 6 months of therapy. None of the study participants experienced any adverse events. All patients showed improvements in hair coverage on both sides of the scalp at 3 and 6 months. On the side with combined treatments, the number of total hairs was significantly increased after 3 (P < 0.001) and 6 months (P = 0.001). A similar increase was also observed on theminoxidil-only side, at both 3 (P < 0.001) and 6 months (P < 0.001). No statistically significant differences were detected between sides (P > 0.05). Additional improvement was not observed with the association of photobiomodulation to topical minoxidil in male AGA. Differences from previous studies that might have influenced our result includenon-collimated light source, higher dosimetry, and a cohort with darker skin phototype and more severe alopecia. Lasers Surg. Med. 2021. © 2021 Wiley Periodicals LLC.

Chronological Gene Expression of Human Gingival Fibroblasts with Low Reactive Level Laser (LLL) Irradiation.

Though previously studies have reported that Low reactive Level Laser Therapy (LLLT) promotes wound healing, molecular level evidence was uncleared. The purpose of this study is to examine the temporal molecular processes of human immortalized gingival fibroblasts (HGF) by LLLT by the comprehensive analysis of gene expression. HGF was seeded, cultured for 24 h, and then irradiated with a Nd: YAG laser at 0.5 W for 30 s. After that, gene differential expression analysis and functional analysis were performed with DNA microarray at 1, 3, 6 and 12 h after the irradiation. The number of genes with up- and downregulated differentially expression genes (DEGs) compared to the nonirradiated group was large at 6 and 12 h after the irradiation. From the functional analysis results of DEGs, Biological Process (BP) based Gene Ontology (GO), BP ‘the defense response’ is considered to be an important process with DAVID. Additionally, the results of PPI analysis of DEGs involved in the defense response with STRING, we found that the upregulated DEGs such as CXCL8 and NFKB1, and the downregulated DEGs such as NFKBIA and STAT1 were correlated with multiple genes. We estimate that these genes are key genes on the defense response after LLLT.

Low-level laser irradiation in the comprehensive treatment of acute renal damage

Background. The discussed topic is worth attracting attention because of its high mortality rate in patients with acute renal damage which is caused by urological and surgical diseases. The membrane-destructive component in damaged renal tissues is manifested with decreased glomerular filtration rate, increased endotoxin level and lipid aberrations. The standard infusion and antibacterial therapy does not fully compensate the severity of pathological changes.Purpose. To study the effectiveness of low-level laser irradiation at endotoxicosis and lipid metabolism indicators in acute renal damage in acute experimental peritonitis.Material and methods. Lipid peroxidation, membrane-destructive processes in renal tissues as well as lipid metabolism and endotoxicosis were studied in the experiment with dogs. The effectiveness of infusion and antibiotic therapy and combined therapy with laser light were compared.Basic results: the experiment has demonstrated that acute renal damage was caused by systemic inflammatory diseases of non-urological profile. The applied low-level laser irradiation (LLLI) promoted more rapid correction of pathological processes which were manifested with increased concentration of cholesterol esters, total phospholipids, phosphatidylserine; LLLI decreased levels of cholesterol, phosphatidylcholine, triacylglycerol, phosphatidylinositol, triacylglycerol, phosphatidylinositol, diacylglycerol, lysophospholipids, free fatty acids and endotoxicosis parameters.Conclusion: the obtained results reliably indicate a LLLI positive effect at the organism’s potentials to recover when LLLI is included into the comprehensive therapy (under experiment). This is evidently seen in the restoration of lipid component in elements of renal parenchyma and in the decrease of lipid peroxidation activity.

RETRACTED ARTICLE: ATP level in red blood cells improves by altering the low-level DPSS laser irradiation condition

The effects of DPSS laser irradiating stored blood at 405, 589, and 670 nm on the ATP levels in human red blood cells have been studied in comparison. Human blood samples were taken from healthy donors’ whole blood and stored. A DPSS laser with different wavelengths was used as a radiation source, with an output power of 10 mW and a fluence of 70 J/cm2 per irradiated sample. The CellTiter-GloLuminescent Assay kit (Promega) was used to determine ATP levels in RBCs. The blood was kept for a maximum of 20 days, and samples were evaluated on days 0, 5, 10, 15, and 20 before and after irradiation. The red blood cell ATP level was calculated by optical density using an ELISA reader to test the emission intensity. No significant differences in RBCs counts were found between pre- and post-irradiated cells at various storage periods with different laser wavelengths. In contrast, at a laser wavelength of 589 nm with storage times of 5, 10, 15, and 20 days, the RBCs had more significant differences (P < 0.05, P < 0.05, P < 0.03, P < 0.02, respectively) between pre- and post-irradiated cells. Moreover, various DPSS lasers were applied and were found to induce significant changes in ATP levels (P < 0.0003, P < 0.04, and P < 0.01, respectively). The highest increase in the ATP level (4.9%) was observed when the laser dose of 70 J/cm2 was delivered at a 589 nm wavelength. Our results clearly demonstrate that red blood cell radiation with low-power lasers of 405, 589, and 670 nm increases the ATP level in RBCs compared with their non-irradiated counterparts at various storage times. This, it is suggested that laser DPSS can cause structural transformations of the red blood cell membrane or components of the membrane.

English

BACKGROUND In recent days a high success rate has been documented for dental implants as a treatment option for missing teeth replacement. Low level laser therapy (LLLT) is a novel therapeutic modality reported to enhance bone healing. Few studies reported that LLLT enhances proliferation and differentiation of osteoblasts and also reduces postoperative pain. The purpose of this study was to assess if post-operative lowlevel laser irradiation of the implant site has any influence on crestal bone loss and pain reduction around dental implants. METHODS In this split mouth randomised study, 9 subjects with bilateral edentulous sites in the mandibular posterior region willing for replacement were taken into consideration. A total of 30 implants were placed on either side of the mandible followed by Low Level Laser irradiation on the test side immediately after implant placement, on 4th and 7th day. Crestal bone level assessment was done radiographically at 3 months and post-operative pain was assessed using visual analogue scale (VAS) scoring by patients from baseline to 6 days. Statistical analysis was done using unpaired t test for inter group crestal bone loss and Mann-Whitney U test for intergroup pain reduction scores. RESULTS The mean crestal bone loss of control group was 1.40 with a standard deviation of 0.39 and for test group it was 0.76 with a standard deviation of 0.26. A significant difference was observed between control and test groups with respect to crestal bone loss scores at 3 months. On comparing VAS pain scores between the two groups from day 1 to 6, significant difference between the groups was observed on day 2, 3 and 4 with P-values 0.042, 0.0011, 0.0036 respectively. CONCLUSIONS Low level irradiation around the dental implants showed a significant reduction in crestal bone loss and post-operative pain. KEY WORDS Dental Implant, Low Level Laser Therapy, Crestal Bone Loss, Post-Operative Pain

LLLI promotes BMSC proliferation through circRNA_0001052/miR-124-3p.

Osteoporosis (OP) is a multifactorial bone disease that occurs worldwide. The treatment of OP is still unsatisfactory. Bone mesenchymal stem cell (BMSC) differentiation is a key process in OP pathogenesis. Low-level laser irradiation (LLLI) has been reported to regulate BMSC proliferation, but the role of circRNAs in the LLLI-based promotion of BMSC proliferation remains unclear. CircRNAs are essential molecular regulators that participate in numerous biological processes and have therapeutic potential. miR-124-3p is an essential microRNA (miRNA), and its expression changes are related to BMSC proliferation ability. In the present study, gain-loss function of experiments demonstrated that circRNA_0001052 could regulate the proliferation of BMSCs by acting as a miR-124-3p sponge through the Wnt4/β-catenin pathway. The results of this study strongly suggest that circRNA_0001052 plays an essential role in BMSC proliferation in response to LLLI treatment, which is a potential therapeutic manipulation with clinical applications.