Low-level Laser Therapy Research Articles

Patients Experience Improvements in Pain and Quality of Life When Treated at a Physician Led Integrative Medicine Clinic at a Large Air Force Military Treatment Facility

ObjectiveA large percentage of military treatment facilities (MTFs) offer at least one type of complementary medicine and 80% of patients surveyed felt that integrative therapies should be routinely offered at all MTFs. We are the first to offer the breadth of modalities outlined below in a dedicated MTF Integrative Medicine Clinic (IMC). The purpose of this study was to determine whether the basket of services offered at our IMC improved patient pain and quality of life. Design and SettingPatient outcomes over a three-year period were retrospectively evaluated from a single cohort. Patients referred to the IMC for chronic pain at the MTF recorded pain scores using the Defense and Veterans Pain Rating Scale (DVPRS) and completed the Dallas Pain Questionnaire (DPQ), a 16-item visual analog quality of life questionnaire, at each visit. They also completed a non-validated quality of life question on discharge from the clinic. Modalities used include microcurrent therapies, extracorporeal shockwave therapy, medical Acupuncture, myofascial release techniques, low-level laser therapy, and the AllCore360. Results761 patients were seen from August 2019 to October 2022 in over 3,280 clinic visits. On average per visit, DVPRS scores were reduced from 4.4 to 1.5 (MD 2.9; 95%CI, 2.7-3.1). Total DPQ scores were reduced by 16.5% (MD 27.7; 95%CI 22.7-32.7). On discharge from the clinic 81% of patients reported their quality of life was either “a lot better” or “somewhat better.” ConclusionsIf implemented, we believe comparable clinics across the Department of Defense can replicate these improvements in patient-oriented outcomes.

Does low-energy fractional carbon dioxide laser therapy improve hair regrowth in female-pattern hair loss?

Background Female-pattern hair loss (FPHL) has the potential to impact the quality of life, physical attractiveness, and interpersonal relationships of many patients. In recent years, lasers and light therapy have been used as alternatives or supplementary therapy for hair loss. Objective To evaluate the efficacy of ablative fractional carbon dioxide (CO2) laser therapy alone in improving hair growth in FPHL. Patients and methods Thirty patients presenting with FPHL were included in a split-scalp prospective interventional study. Two areas of the scalp were studied. One area was treated with fractional CO2 laser and the second was injected with intradermal saline as control. The sessions were scheduled every 2 weeks for four sessions then monthly for 2 months. Patients were evaluated after each session and 2 months after the last session. Results were evaluated by clinical photography, trichoscopic, and folliscopic examination regarding the count of terminal and vellus hair, the thickness and density of hair shafts, and the patient’s satisfaction score. Results Fractional CO2 laser therapy alone was found to be effective in improving hair growth in FPHL. Conclusion Fractional CO2 laser therapy would have potential mechanisms in inducing hair regrowth in FPHL. However, the detailed mechanisms underlying hair regrowth and injury induced by the laser need further clarification.

Effect of Low-Level Laser Therapy on Osseointegration of Immediate Dental Implants in Anterior and Premolar Region of the Mandible: A Pilot Clinical Study

Effect of Low-Level Laser Therapy on Osseointegration of Immediate Dental Implants in Anterior and Premolar Region of the Mandible: A Pilot Clinical Study

Effectiveness of red and infrared low-intensity laser therapy (LLLT) for reducing local manifestations by Bothrops envenoming in patients at the tropical medicine center of rondônia (CEMETRON)

Effectiveness of red and infrared low-intensity laser therapy (LLLT) for reducing local manifestations by Bothrops envenoming in patients at the tropical medicine center of rondônia (CEMETRON)

Sleep bruxism in children main methods of treatment: a systematic review with meta-analysis.

Sleep bruxism is both masticatory muscle activities characterized by repeated or prolonged tooth contact as well as bracing or thrusting of the jaw. This meta-analysis evaluates the differences between sexes and which therapy is most effective in treating bruxism. A literature search was performed on PubMed, Lilacs, Web of Science and Scopus, and articles published from 2000 to 2022 were considered according to the keywords entered. The term "Bruxism" has been combined with "Children" using the boolean connector AND. At the end of the research, 1462 studies were identified from the search conducted on the three engines. Only four were chosen to draw up the present systematic study. The Forrest plot found that photo biomodulation therapy has a higher efficacy (Odds Ratio (OR) 0.10; 95% Confidence Interval (CI) from 0.03 to 0.43), followed by treatment with hydroxyzine (OR 0.19; 95% CI from 0.03 to 1.04). The average between girls and boys with bruxism is 18.5 for boys and 19.5 for girls. This meta-analysis showed that treatment by photobiomodulation has more significant effects on bruxism, followed by treatment with hydroxyisalazine. However, this meta-analysis has limitations due to the diversity of treatment evaluation methods.

Efficacy Comparison of Low Level Laser Treatment with Muscle Energy Procedure Among Diabetic Patients Suffering from Frozen Shoulder

Frozen shoulder incidence in diabetic patient is twice as high as normal controls. There are various conventional as well as electrotherapies for its treatment within which low-level laser therapy versus muscle energy technique are well debated for efficacy in diabetic patients frozen shoulder. Objective: Comparative analysis of effectiveness of low-level laser therapy and muscle energy technique among diabetic patients with frozen shoulder. The study design was comparative study. The Place and Duration of Study was Department of Orthopaedic, Indus Medical College, Tando Muhammad Khan from 1st January 2023 to 30th June 2023. Methods: One hundred and twenty patients who were having diabetes mellitus (type 1 and type 2) and suffering from frozen shoulders were enrolled. The conventional therapeutic exercise included exercises like pendulum, arm overhead, finger wall ladder, twisting arm outwards, overhead pulley, cross-body reach exercises, hand behind-back exercise and outward rotation exercise. Muscle energy technique was administered in cases where restriction in shoulder flexion, as well as abduction, external rotation was observed. Results: There were 59% females and 41% males with majority being within the age group of 45-65 years. It was observed that there was a significant variance between pain scores at pretreatment and post treatment stages with highest value decrease observed in muscle energy technique group II. The ROM was least improved in control group only treated through conventional protocol. Conclusions: The Muscle energy technique is slightly more effective than low-level laser therapy technique in terms of pain, inflammation reduction and angular movements.

Adjunctive Approach to Therapeutic Laser and Exercise Therapies in Alleviating Pain and Disability in Patients with Low Back Pain: A Systematic Review.

Low back pain (LBP), a globally prevalent musculoskeletal condition, affects mobility, mental well-being, and overall quality of life. It is generally caused by disc degeneration, muscular strain, ligamentous sprain, or a disease located at the lumbar spine. Owing to this disability, the social and occupational interactions of an individual might get affected. Modern medicine frequently combines exercise therapy with light amplification by stimulated emission of radiation (LASER) therapy, especially high intensity LASER therapy (HILT) or low level LASER therapy (LLLT), to increase the efficacy of the treatment modalities for LBP. This review aimed to determine the effect of the combined approach of LASER and exercise therapies in managing pain and reducing disability in patients with LBP. PubMed, Google Scholar, Cochrane Library, MEDLINE, and PEDro were searched for full-text research articles published from 2000 to 2023. Overall, 3,913 records were screened from these databases and six high methodological quality studies (PEDro ≥ 5) were included in this review after eligibility assessment. Review manager 5.4.1 was utilized to evaluate the overall quality of the review articles. In conclusion, HILT and LLLT serve as effective adjuncts to exercise therapy in treating LBP, contributing to pain reduction and disability alleviation.

Photobiomodulation ameliorates ovarian aging by alleviating oxidative stress and inflammation damage and improving mitochondrial function

Ovarian aging is a serious clinical concern. Few safe and effective methods are currently available to improve ovarian functions. Photobiomodulation (PBM) is a safe and noninvasive physical therapy that can modulate a series of biological processes. Recently, several studies have noted its potential to improve the function of ovary and reproductive cells. However, the effects of PBM treatment on natural ovarian aging remain unclear. In this study, we used a naturally reproductive aging mouse model to observe the effect of PBM on ovarian function. Young and aged female ICR mice were treated with or without PBM for 2 months. PBM was performed using a semiconductor InGaAlP laser emitting at 650 nm (80 mW, 6.7 mW/cm2 for 5 or 10 min, resulting in a dose of 2 or 4 J/cm2, respectively). After treatment, the effects of PBM and its role in oxidative stress, inflammation, and mitochondrial function were investigated. We found that PBM (4 J/cm2) effectively recovered the levels of sex hormones, increased the number of primordial and growing follicles, improved angiogenesis, and decreased cell apoptosis in naturally aged mice. Moreover, PBM reduced oxidative stress, inhibited chronic ovarian inflammation, and improved mitochondrial function in aged ovaries. Similar protective effects of PBM were observed in a hydrogen peroxide-induced oxidative stress model of human granulosa cell line (KGN) in vitro. Increased cell viability, cell proliferation, hormone secretion, mitochondrial membrane potential, and adenosine triphosphate levels and decreased apoptosis and oxidative stress were detected in KGN cells after PBM treatment. Collectively, this study suggest that PBM treatment is beneficial for restoring ovarian function in naturally reproductive aging mice and has a significant protective effect against oxidative stress damage in KGN cells. The mechanisms underlying the benefits of PBM in ovarian aging include antioxidant stress, reduction of inflammation, and preservation of mitochondrial function. Therefore, this study emphasizes the potential of PBM as a therapeutic intervention to ameliorate ovarian aging.

Effects of Photobiomodulation Application on Glutathione-Related Antioxidant Defense System in Rabbit Eye Tissues.

Photobiomodulation (PBM) has emerged as a potentially effective therapeutic approach to modulate cellular functions. This study aimed to examine the impact of PBM on reactive oxygen species (ROS), lipid peroxidation, and glutathione-related antioxidant defense systems in rabbit eye tissues. A polychromatic light source with an intensity of 2.6 J/cm2/min was used for PBM treatment in New Zealand White rabbits for 12 min. The PBM group (n = 8) received treatments every 2 days for a total of 12 sessions, whereas the control group (n = 8) did not undergo any PBM light exposure during the same period. The application of PBM significantly elevated ROS-mediated glutathione levels, along with increased activities of glutathione peroxidase and reductase, particularly in corneal tissue (p ≤ 0.05). In conclusion, PBM treatment effectively enhances antioxidant defense mechanisms in the eye, particularly in corneal tissue, suggesting its potential as a therapeutic strategy for managing oxidative stress-related ocular conditions.

In-vitro study on type I collagen synthesis in low-level laser therapy on the early ligament fibroblasts’ healing process

BackgroundLow-level Laser Therapy (LLLT) has demonstrated its potential in promoting fiber matrix maturation, collagen synthesis, and fibroblast proliferation, contributing to tissue regeneration. Our study aimed to investigate the impact of LLLT on collagen type I synthesis, cell proliferation, and viability in human ligament fibroblasts derived from the Anterior Cruciate Ligament (ACL).MethodsTissue samples were obtained from individuals undergoing arthroscopic ACL reconstruction surgery. Primary human fibroblasts were isolated, and immunohistochemical assays confirmed their characteristics. LLLT at 850 nm was administered in three groups: Low dose (1.0 J/cm²), High dose (5.0 J/cm²), and Control (0.0 J/cm²). Cell viability was calculated using a membrane integrity assay, proliferation was determined by automated counting, and collagen type I concentration in cell culture was measured using an immunoassay.ResultsFibroblasts showed decreased viability after low and high doses of LLLT, increased proliferation at the low dose, and increased collagen synthesis at the high dose on day 10 for both sexes after treatment.ConclusionOur study demonstrated that LLLT may improve the early ligament healing process by increasing cell proliferation at the low dose and enhancing collagen type I synthesis at the high dose in human ligament fibroblasts.

Major aspects of the use of bisphosphonates and the formation of osteonecrosis in the involvement of dental implants: a systematic review

Introduction: Bisphosphonates are widely used to treat osteoporosis and malignant tumors due to their effectiveness in increasing bone density and inhibiting bone resorption. Dental patients receiving bisphosphonate treatment are at higher risk of bisphosphonate-related osteonecrosis of the jaws (BRONJ), necessitating dentists' awareness of these risks. Objective: It was to highlight the main aspects of the use of bisphosphonates and the formation of osteonecrosis in the involvement of dental implants, as well as possible treatments. Methods: The PRISMA Platform systematic review rules were followed. The search was carried out from April to July 2024 in the Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: A total of 120 articles were found, 40 articles were evaluated in full and 15 were included and developed in the present systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 14 studies with a high risk of bias and 21 studies that did not meet GRADE and AMSTAR-2. Most studies did not show homogeneity in their results, with X2=89.5%>50%. Therefore, the present study suggests that patients undergoing treatment with BFs should be informed about the potential risk of BRONJ. Furthermore, it would be advisable for providers responsible for BF therapy to refer patients for dental check-ups before starting treatment, allowing for patient monitoring by a multidisciplinary team. Although the morbidity rate of this pathology is not high, prevention should be mandatory, thus avoiding mutilating and painful processes. However, if surgery is necessary, the use of these new adjuvant therapies, such as lowlevel laser therapy and magnetotherapy, can be proposed in the treatment of BRONJ. It is essential to increase our caseload and also involve other institutions in the use of these new effective and safe therapies in BRONJ.

The challenge of composite graft: the use of fluorescent light energy to improve engraftment

Composite graft is a useful tool for the reconstruction of specific facial aesthetic subunits with a single surgical stage. This technique, when successful, gives optimal results in the reconstruction of small defects of nose, ear, eyelid and lips. The aim of this work is to optimize the attachment of composite grafts in the reconstruction of small complex facial defects by combining it with Fluorescent Light Energy (FLE) during the healing process of the graft. The beneficial effects of photobiomodulation (PBM) on wound healing might be attributed to anti-inflammatory signaling, cell proliferation, protein synthesis, and decreased bacterial infection. We previously experienced rewarding achievements using Photonic energy in the treatment of burns, non-healing wounds and pathological scars. Therefore, we chose to exploit the potential of bioluminescent energy to maximize aesthetical and functional results, enhancing the formation of new vascular connections and modulating both inflammatory and scarring processes. From the 2nd postoperative day, the patients were locally treated with 5 FLE sessions every (48/72 h) 2 or 3 days. We evaluated results in terms of time for engraftment, quality of the scarring, infective complications and morbidity of the donor site. Graft survival is subject to many factors, both local and systemic. To overcome these issues, various methods have been studied and described. We here report the successful reconstruction of full-thickness defects of the free margin of the nasal alar rim and the central portion of the inferior lip with a composite graft. These results were highly encouraging if compared with the literature. By analyzing our small cohort, we demonstrated how new technologies may push this traditional reconstructive procedure beyond their old boundaries: overcoming an increased size demand or a potential infective wound environment.

Combined application of Er:YAG laser and low-level laser in non-surgical treatment of periodontitis.

To compare the efficacy of combined treatment of Er:YAG laser (ERL) and low-level laser therapy (LLLT) with single laser applications, and scaling and root planing (SRP) for non-surgical periodontal treatment. In a randomized controlled trial, 25 non-smoking Stage II or Stage III periodontitis patients were recruited. The four intraoral quadrants were randomly assigned to four different treatments: (1) combined application with ERL plus SRP plus LLLT; (2) ERL plus SRP; (3) SRP plus LLLT; and (4) SRP. We assessed periodontal indexes, including probing depth (PD), clinical attachment level (CAL), bleeding index (BI), and plaque index (PLI), along with three cytokines (IL-1β, TNF-α, IL-10) from gingival crevicular fluid and red complex pathogens from subgingival dental plaque at baseline, 3 months, and 6 months. For initial moderate pockets (4mm≤PD≤6mm), quadrants treated with ERL+SRP+LLLT, ERL+SRP, and SRP+LLLT exhibited greater PD improvement compared to the control (SRP) quadrants at the 3-month follow-up (1.25±1.06, 1.23±1.12, 1.00±1.21vs. 0.98±1.21mm) and the 6-month follow-up (1.35±1.06, 1.23±1.17, 1.35±0.98vs. 0.98±1.23mm) (p=0.002). Quadrants treated with ERL+SRP+LLLT and SRP+LLLT showed more CAL gain means than the control quadrants at the 3-month follow-up (0.96±1.42, 0.61±1.39vs. 0.55±1.57mm) and the 6-month follow-up (0.84±1.54, 0.89±1.49vs. 0.48±1.68mm) (p=0.008). For initial deep pockets (PD≥7mm), the ERL+SRP+LLLT quadrants had more PD improvement and CAL gain compared to the control quadrants at follow-up. There were no significant differences in BI, PLI, inflammatory cytokines, and periodontal pathogens among the four groups. The combined application of ERL and LLLT demonstrated potential efficacy in reducing PD, particularly for deep pockets. To compare the therapy effect of combined use of Er:YAG laser (ERL) and low level laser therapy (LLLT) with single laser applications, and traditional periodontal treatment (SRP). A total of 25 nonsmoking patients with periodontitis were involved, and their mouths were divided into four sections, each receiving a different treatment: ERL+SRP+LLLT, ERL+SRP, SRP+LLLT, and SRP. Clinical indexes and laboratory indicators were assessed at baseline, 3 months, and 6 months. After six months, for initial moderate pockets, combined laser group and single laser group showed better improvements than traditional group in reducing the depth of periodontal pockets and increasing attachment levels. But for initial deep pockets, only combined laser group showed better improvement than traditional group. There were no significant differences in bleeding, plaque, inflammation, or harmful bacterial levels among the groups. These findings suggest that the integration of Er:YAG laser and lowlevel laser therapy into standard periodontal treatment may enhance the treatment's benefits in reducing pocket depth, especially for severe conditions.

Evaluation of the Effect of Low-Level Laser Therapy Versus Photodynamic Therapy on the Level of Serum IL-17 and Salivary IL-4 in Patients Suffering from Erosive/Atrophic Oral Lichen Planus: A Case Control Study

Evaluation of the Effect of Low-Level Laser Therapy Versus Photodynamic Therapy on the Level of Serum IL-17 and Salivary IL-4 in Patients Suffering from Erosive/Atrophic Oral Lichen Planus: A Case Control Study

Three-dimensional assessment of low-level laser therapy on orthodontic miniscrew displacement using CBCT: a retrospective study

BackgroundThis study aimed to assess the effect of Low-Level Laser Therapy (LLLT) on sagittal, transverse and vertical Orthodontic miniscrew displacement.Materials and methodsThe study included CBCTs from the records of 12 adult patients who underwent upper first premolar extraction and canine retraction with orthodontic miniscrews for maximum anchorage. The miniscrews on one side received LLL, while the other side served as a control. The Low-Level Laser was applied to assess its effect on the displacement of the miniscrews. The used CBCTs have been taken at two-time points: immediately after miniscrew insertion (T0) and four months after the start of canine retraction (T1) with a total of 24 CBCTs. Miniscrew displacement was assessed by measuring head (HMS) and tail (TMS) displacement to the axial, coronal and mid-sagittal planes on the CBCT at the two time points. Miniscrews displacement (T1-T0) was compared between LLL side and control side. Comparisons were performed using paired samples t-test. The significance level was set at p-value < 0.05. The reproducibility of measurements was assessed by intraclass correlation coefficient (ICC).ResultsAfter four months of canine retraction, HMS and TMS from both laser and control sides showed significant three-dimensional displacement at p < 0.05. No significant difference in mean displacement in the vertical, sagittal, nor transverse planes between both sides was elicited.ConclusionLLL application in the used protocol does not affect the amount of miniscrew displacement in any of the three planes of space. Miniscrew displacement was significant in both groups.

Photobiomodulation Dose-Response on Adipose-Derived Stem Cell Osteogenesis in 3D Cultures.

Osteoporosis and other degenerative bone diseases pose significant challenges to global healthcare systems due to their prevalence and impact on quality of life. Current treatments often alleviate symptoms without fully restoring damaged bone tissue, highlighting the need for innovative approaches like stem cell therapy. Adipose-derived mesenchymal stem cells (ADMSCs) are particularly promising due to their accessibility, abundant supply, and strong differentiation potential. However, ADMSCs tend to favor adipogenic pathways, necessitating the use of differentiation inducers (DIs), three-dimensional (3D) hydrogel environments, and photobiomodulation (PBM) to achieve targeted osteogenic differentiation. This study investigated the combined effects of osteogenic DIs, a fast-dextran hydrogel matrix, and PBM at specific wavelengths and fluences on the proliferation and differentiation of immortalized ADMSCs into osteoblasts. Near-infrared (NIR) and green (G) light, as well as their combination, were used with fluences of 3 J/cm2, 5 J/cm2, and 7 J/cm2. The results showed statistically significant increases in alkaline phosphatase levels, a marker of osteogenic differentiation, with G light at 7 J/cm2 demonstrating the most substantial impact on ADMSC differentiation. Calcium deposits, visualized by Alizarin red S staining, appeared as early as 24 h post-treatment in PBM groups, suggesting accelerated osteogenic differentiation. ATP luminescence assays indicated increased proliferation in all experimental groups, particularly with NIR and NIR-G light at 3 J/cm2 and 5 J/cm2. MTT viability and LDH membrane permeability assays confirmed enhanced cell viability and stable cell health, respectively. In conclusion, PBM significantly influences the differentiation and proliferation of hydrogel-embedded immortalized ADMSCs into osteoblast-like cells, with G light at 7 J/cm2 being particularly effective. These findings support the combined use of 3D hydrogel matrices and PBM as a promising approach in regenerative medicine, potentially leading to innovative treatments for degenerative bone diseases.

Unraveling the RAGE-NF-κB pathway: implications for modulating inflammation in diabetic neuropathy through photobiomodulation therapy.

Diabetic peripheral neuropathy (DPN) is a primary complication observed in diabetes that severely affects quality of life. Recent evidence suggests that photobiomodulation (PBM) is a promising therapy against painful conditions and nerve damage. However, the effects of PBM on DPN remains mostly unknown. In the present study, we investigated the efficacy of PBM therapy in modulating proinflammatory cytokine expression in both central and peripheral nervous systems of rats with Streptozotocin (STZ)-induced type 1 diabetes. Male Wistar rats were allocated into control (naïve), diabetic (STZ), and treatment (STZ + PBM) groups. A single intraperitoneal (i.p.) injection of STZ (85mg/kg) was administered for the induction of diabetes. Animals were subjected to 10 treatment sessions, every other day. The results herein presented indicate that PBM treatment diminishes Receptor for Advanced Glycation End-products (RAGE) and Nuclear Factor Kappa B (NF-ϰB) expression in peripheral nervous system and suppresses TNF-α expression in central nervous system tissues. Furthermore, PBM-therapy in diabetic rats also induces increased levels of the anti-inflammatory protein IL-10 in both peripheral and central nervous system. Collectively, our findings demonstrate compelling evidence that PBM-therapy modulates cytokine dynamics and influences RAGE/NF-ϰB axis in a STZ-induced model of type 1 diabetes.

Photobiomodulation Using 830 nm Lighting-Emitting Diode Inhibits Melanogenesis via FOXO3a in Human Melanocyte.

Photobiomodulation (PBM) using 830 nm light-emitting diode (LED) benefits tissue regeneration, wound healing and neural stimulation. However, there is not much exploration of its effect on melanocytes and exvivo skin model. This study aims to investigate the mechanism behind the anti-melanogenic activity of 830 nm LED and provides evidence for its activity in human exvivo skin model. Our results showed that 830 nm LED at fluences ranging from 5 to 20 J/cm2 inhibited melanosome maturation and reduced melanin content, tyrosinase activity and melanogenesis-related proteins. 830 nm LED inhibited the phosphorylation of AKT and its downstream FOXO3a, leading to nuclear translocation of FOXO3a. Furthermore, FOXO3a knockdown and AKT activator like SC79 could reverse the melanogenesis inhibition phenotype induced by 830 nm LED. In human exvivo skin model, Fontana-Masson staining revealed a decrease in epidermal basal pigmentation after 830 nm LED irradiation. Taken together, 830 nm LED demonstrated the anti-melanogenic activity via FOXO3a.

Photobiomodulation Mitigates PM2.5-Exacerbated Pathologies in a Mouse Model of Allergic Asthma.

Exposure to particulate matter (PM), especially PM2.5, is known to exacerbate asthma, posing a significant public health risk. This study investigated the asthma-reducing effects of photobiomodulation (PBM) in a mice model mimicking allergic airway inflammation exacerbated by PM2.5 exposure. The mice received sensitization with ovalbumin (OVA) and were subsequently treated with PM2.5 at a dose of 0.1 mg/kg every 3 days, for 9 times over 3 weeks during the challenge. PBM, using a 610 nm wavelength LED, was applied at 1.7 mW/cm2 to the respiratory tract via direct skin contact for 20 min daily for 19 days. Results showed that PBM significantly reduced airway hyperresponsiveness, plasma immunoglobulin E (IgE) and OVA-specific IgE, airway inflammation, T-helper type 2 cytokine, histamine and tryptase in bronchoalveolar lavage fluid (BALF), and goblet cell hyperplasia in PM2.5-exposed asthmatic mice. Moreover, PBM alleviated subepithelial fibrosis by reducing collagen deposition, airway smooth muscle mass, and expression of fibrosis-related genes. It mitigated reactive oxygen species generation, oxidative stress, endoplasmic reticulum stress, apoptotic cell death, ferroptosis, and modulated autophagic signals in the asthmatic mice exposed to PM2.5. These findings suggest that PBM could be a promising intervention for PM2.5-induced respiratory complications in patients with allergic asthma.

In vivo measurement of nitric oxide release from intact human skin post photobiomodulation using visible and near-infrared light: A chemiluminescence detection study

Significance: This study investigates the therapeutic potential of photobiomodulation (PBM) using visible and near-infrared (NIR) light on nitric oxide (NO) release from intact human skin. Given NO's critical role in physiological processes such as wound healing, inflammation control, and vasodilation, this research could lead to innovative non-invasive treatments.Aim: The primary aim was to explore how PBM at different wavelengths affects NO release from human skin. Custom-built airtight sleeves equipped with gas ports were used to measure NO levels, assessing the impact of three specific wavelengths of light (455 nm, 660 nm, and 850 nm).Approach: Eighteen healthy participants had their forearms enclosed in airtight sleeves. The skin was irradiated with the specified wavelengths at a fluence of 45 J/cm² and an irradiance of 50 mW/cm² for 15 min. NO levels were quantified after irradiation using chemiluminescence detection (CLD), which measures the chemiluminescent reaction of NO with ozone (O3) for real-time analysis.Results: Significant differences in NO release were observed among the wavelengths tested, indicating that PBM stimulates NO release from intact human skin.Conclusions: The study provides strong evidence that PBM using visible and NIR light can enhance NO release from human skin, suggesting potential therapeutic applications for conditions involving NO. Further research is needed to understand the mechanisms behind PBM-induced NO release and its clinical implications.