Effect Of Blue Light Research Articles

A Red‐Emitting La4Ti9O24:Eu3+ Phosphor Excited by Multi‐Wavelength for Healthy Lighting

Herein, an excellent red‐emitting La4Ti9O24:Eu3+ phosphor is produced using eco‐friendly hydrothermal and heat treatment techniques without a high‐temperature and multiple‐sintering process. The phosphor can be excited by multiwavelength light from 382 to 533 nm, and the three main characteristic emission peaks of Eu3+ ions are located at 592, 616, and 709 nm. Its decay time measured at 616 nm is calculated to be 3.32 ms. The color coordinates of La4Ti9O24:Eu3+ phosphor excited by 393 nm ultraviolet (UV) light are (0.665, 0.335), which are near to the Commission International de L'Eclairage (CIE) of red light (0.67, 0.33). A red light‐emitting diode was fabricated by the red‐emitting La4Ti9O24:Eu3+ phosphor encapsulating on a UV‐emitting chip (λ = 395 nm), eliminating the harmful effects of blue light on human eyes. Consequently, it would be a viable source of healthy illumination for display and lighting.

Effect of Blue and Red LED Light and some Plant Extract on Lettuce Growth and Yield in NFT Technique

This experiment was carried out in the College of Agricultural Engineering Sciences, Univ. of Baghdad, during autumn 2021 growing season to investigate possibility study of increase lettuce antioxidant and biological yield, growing and producing lettuce hydroponically under film technique (NFT) using a globally approved standard solution (Cooper solution), Nested design with three replications adopted in the experiment, each of them included in main plot the first factor, which is LED light (B and R), Then levels of second factor were randomly distributed within each replicate, which included spraying with organic nutrients which was Cymbopogon citratus and Hibiscus sabdariffa at two concentrations 2.5 and 5 % for each of them, As well as control treatment T0, symbolized as T1, T2, T3, T4 respectively. The results showed R led light and T4 increase most parameters, B Led light treatment maximized lettuce quality parameters (chlorophyll, V.C., Total and Beta Carotene), T3 increase Total chlorophyll and Carotene T4 increased V.C. and Beta carotene, R led light and T4 increased yield.

Beneficial effects of red and blue light on potato leaf antioxidant capacity and tuber bulking.

Artificial light application is an effective method for promoting potato production in indoor facilities. In this study, we assessed the effects of different combinations of red (R) and blue (B) light application on potato leaf and tuber growth. Potato plantlets were transplanted under W (white light, control), RB5-5 (50% R + 50% B), RB3-7 (30% R + 70% B to 70% R + 30% B) and RB1-9 (10% R + 90% B to 90% R + 10% B), and ascorbic acid (AsA) metabolism in leaves and cytokinin (CTK), auxin (indole-3-acetic acid, IAA), abscisic acid (ABA), and gibberellin (GA) levels in tubers were measured. At 50days of treatment, potato leaves had significantly higher L-galactono-1,4-lactone dehydrogenase (GalLDH) activity and utilized AsA faster under RB1-9 treatment than under RB3-7 treatment. CTK/IAA and ABA/GA ratios in large tubers under W treatment did not differ significantly from those under RB1-9 treatment, which had higher levels than those under RB5-5 and RB3-7 treatment at 50days. However, under RB1-9 treatment, total leaf area decreased rapidly from 60 to 75days compared with plants under RB3-7 treatment. Tuber dry weight per plant under W and RB5-5 treatment approached a plateau at 75days. At 80days, RB3-7 treatment significantly improved ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase activity compared with RB1-9 treatment. RB1-9 treatment with a high ratio of blue light increased CTK/IAA and ABA/GA to improve tuber bulking at 50days, while RB3-7 treatment with a high ratio of red light stimulated AsA metabolic pathway to delay leaf oxidation and maintain tuber biomass accumulation at 80days. For the indoor potato cultivation, RB3-7 treatment had a higher proportion of medium-sized tubers, thus being a suitable light treatment.

A Study on the Effect and Prevention of Blue Light on Eyes

Abstract: In recent years, large number of people complaining about rteh effects of light pollution on their eyes. Blue light with the wavelength range between 415nm and 455nm is much nearly related with eye damage in the visible range. High energy blue light damages the hormonal balance and negatively impacts sleep quality by passing from the cornea to retina. Here it led to many types of disease such as cataract, age related degeneration and dry eye. It also stimulates the brain, inhibits melatonin secretion, and increases the production of adrenocortical hormones. Consequently, the impact of Blu-rays on the eye is growing in significance going forward. The effects of blue light on ocular tissues are highlighted in this study, along with a summary of the studies on eye injuries, physical preventative measures, and medical care.

Low-Intensity Blue Light Exposure Reduces Melanopsin Expression in Intrinsically Photosensitive Retinal Ganglion Cells and Damages Mitochondria in Retinal Ganglion Cells in Wistar Rats.

This study investigated the effect of low-intensity blue light on the albino Wistar rat retina, including intrinsically photosensitive retinal ganglion cells (ipRGCs). Three groups of nine albino Wistar rats were used. One group was continuously exposed to blue light (150 lx) for 2 d (STE); one was exposed to 12 h of blue light and 12 h of darkness for 10 d (LTE); one was maintained in 12 h of white light (150 lx) and 12 h of darkness for 10 d (control). Melanopsin (Opn4) was immunolabelled on retinal whole-mounts. To count and measure Opn4-positive ipRGC somas and dendrites (including Sholl profiles), Neuron J was used. Retinal cryosections were immunolabeled for glial fibrillary acid protein (GFAP) and with terminal deoxynucleotidyl transferase dUTP nick-end labelling for apoptosis detection. LTE reduced the length of Opn4-positive ipRGC dendrites (p = 0.03) and decreased Opn4-immunoreactivity in ipRGC outer stratifying dendrites. LTE and STE decreased the complexity of dendritic arborization (Sholl profile; p < 0.001, p = 0.03, respectively), increased retinal GFAP immunoreactivity (p < 0.001, p = 0.002, respectively), and caused outer segment vesiculation and outer nuclear layer apoptosis. Ultrastructural analysis showed that LTE damaged mitochondria in retinal ganglion cells and in the inner plexiform layer. Thus, LTE to low-intensity blue light harms the retinas of albino Wistar rats.

Impact of blue light exposition to alertness of shift workers, patients with sleep deprivation, Alzheimer’s disease, or post-traumatic stress disorder

Introduction and purpose:&#x0D; &#x0D; In certain professions it is necessary to work at night and to maintain alertness and concentration at that time. Additionally in some conditions such as Alzheimer’s disease and post-traumatic stress disorder sleep deprivation is both a symptom and an aggravating factor. A non-pharmacological method is needed to impact the maintenance of concentration and to help the workers adapt to shift work as well as improve their sleep quality. The purpose of this paper is to present recent scientific findings on the effects of blue light on improving concentration and attentiveness in shift workers and people suffering from sleep disorders, Alzheimer's disease, or post-traumatic stress disorder.&#x0D; &#x0D; &#x0D; A brief description of the state of knowledge:&#x0D; Circadian rhythm is a mechanism, which regulates daily functioning of humans and a variety of other species. Light exposure, especially to blue light, is the most crucial factor disrupting circadian consistency. The relationship between the time maladjustment, biological rhythms and factors from the outside world is called phase angle of entrainment.&#x0D; Summary:&#x0D; &#x0D; Studies conducted on various groups have shown the effectiveness of modified light interventions on concentration and focus during shift work at night.&#x0D; Exposure to blue light appears to be a safe method that can improve work quality, concentration and focus in people who work at night. Exposure to light brings hope for improving the quality of life of people with Alzheimer's disease and maintaining their independence longer, which can ease the burden on their caregivers. Establishing some routine in the form of blue light exposure in people with post-traumatic stress disorder also appears to be an easy and accessible method for reducing the severity of PTSD symptoms, especially sleep disturbances.

Blue Light Inhibits Proliferation of Metastatic Cancer Cells by Regulating Translational Initiation: A Synergistic Property with Anticancer Drugs.

The aim of this study was to examine the inhibitory effect of blue light (BL) on the proliferation of metastatic cancer cells and synergistic properties with chemo-drugs. BL significantly inhibited the proliferation of B cell lymphoma (A20 and RAMOS) cells in a dose-dependent manner. Anti-proliferative effect of BL irradiation was identified to be associated with the inhibition of proliferating-cell nuclear antigen expression and cell cycle by decreasing S-phase cells. Consistent with its inhibitory effects, BL irradiation at 20 J/cm2 daily for 10 days inhibited metastasis of cancer cells which were distributed and invaded to other organs including bone marrow, liver, kidney, etc., and induced paraplegia, thereby leading to an increased survival rate of tumor-bearing mice. Anti-proliferative activity of BL was expanded in solid tumor cells including pancreatic carcinoma (Mia PaCa-2, PANC-1), lung carcinoma A549 and colorectal carcinoma HCT116 cells. Additionally, combination with chemo-drugs such as 5-FU and gemcitabine resulted in an increase in the anti-proliferative activity after BL irradiation accompanied by regulating mRNA translational process via inhibition of p70S6K, 4EBP-1 and eIF4E phosphorylation during cellular proliferation. These results indicate the anti-metastatic and photo-biogoverning abilities of BL irradiation as a potent therapeutic potential for repressing the progression of tumor cells.

Blue-light background impairs visual exogenous attention shift

Previous research into the effects of blue light on visual-spatial attention has yielded mixed results due to a lack of properly controlling critical factors like S-cone stimulation, ipRGCs stimulation, and color. We adopted the clock paradigm and systematically manipulated these factors to see how blue light impacts the speed of exogenous and endogenous attention shifts. Experiments 1 and 2 revealed that, relative to the control light, exposure to the blue-light background decreased the speed of exogenous (but not endogenous) attention shift to external stimuli. To further clarify the contribution(s) of blue-light sensitive photoreceptors (i.e., S-cone and ipRGCs), we used a multi-primary system that could manipulate the stimulation of a single type of photoreceptor without changing the stimulation of other photoreceptors (i.e., the silent substitution method). Experiments 3 and 4 revealed that stimulation of S-cones and ipRGCs did not contribute to the impairment of exogenous attention shift. Our findings suggest that associations with blue colors, such as the concept of blue light hazard, cause exogenous attention shift impairment. Some of the previously documented blue-light effects on cognitive performances need to be reevaluated and reconsidered in light of our findings.

Data-Independent Acquisition Proteomics Reveals the Effects of Red and Blue Light on the Growth and Development of Moso Bamboo (Phyllostachys edulis) Seedlings

Moso bamboo is a rapidly growing species with significant economic, social, and cultural value. Transplanting moso bamboo container seedlings for afforestation has become a cost-effective method. The growth and development of the seedlings is greatly affected by the quality of light, including light morphogenesis, photosynthesis, and secondary metabolite production. Therefore, studies on the effects of specific light wavelengths on the physiology and proteome of moso bamboo seedlings are crucial. In this study, moso bamboo seedlings were germinated in darkness and then exposed to blue and red light conditions for 14 days. The effects of these light treatments on seedling growth and development were observed and compared through proteomics analysis. Results showed that moso bamboo has higher chlorophyll content and photosynthetic efficiency under blue light, while it displays longer internode and root length, more dry weight, and higher cellulose content under red light. Proteomics analysis reveals that these changes under red light are likely caused by the increased content of cellulase CSEA, specifically expressed cell wall synthetic proteins, and up-regulated auxin transporter ABCB19 in red light. Additionally, blue light is found to promote the expression of proteins constituting photosystem II, such as PsbP and PsbQ, more than red light. These findings provide new insights into the growth and development of moso bamboo seedlings regulated by different light qualities.

Photobiomodulation with Blue Light on Wound Healing: A Scoping Review.

Photobiomodulation consists of inducing healing by irradiating light. This scoping review investigates the effect of blue light on the healing process. The MEDLINE, Web of Science, Scopus, and CINAHL databases were searched. Two reviewers independently examined the search results and extracted data from the included studies. A descriptive analysis was performed. Twenty-two articles were included. Studies were categorized as in vitro/mixed, preclinical, and clinical. The power density used was 10-680 mW/cm2 in most of the in vitro/preclinical studies, the irradiation time ranged from 5 s to 10 min, and different wavelengths and energy densities were used. In clinical studies, the wavelength ranged from 405 to 470 nm, and the energy density varied from 1.5 to 30 J/cm2. A low energy density (<20 J/cm2) was able to stimulate the different cell types and proteins involved in healing, while a high energy density, 20.6-50 J/cm2, significantly reduced cell proliferation, migration, and metabolism. There is a great variety of device parameters among studies, and this makes it difficult to conclude what the best technical specifications are. Thus, further studies should be performed in order to define the appropriate parameters of light to be used.

Blue Light Exposure: Ocular Hazards and Prevention-A Narrative Review.

Exposure to blue light has seriously increased in our environment since the arrival of light emitting diodes (LEDs) and, in recent years, the proliferation of digital devices rich in blue light. This raises some questions about its potential deleterious effects on eye health. The aim of this narrative review is to provide an update on the ocular effects of blue light and to discuss the efficiency of methods of protection and prevention against potential blue light-induced ocular injury. The search of relevant English articles was conducted in PubMed, Medline, and Google Scholar databases until December 2022. Blue light exposure provokes photochemical reactions in most eye tissues, in particular the cornea, the lens, and the retina. In vitro and in vivo studies have shown that certain exposures to blue light (depending on the wavelength or intensity) can cause temporary or permanent damage to some structures of the eye, especially the retina. However, currently, there is no evidence that screen use and LEDs in normal use are deleterious to the human retina. Regarding protection, there is currently no evidence of a beneficial effect of blue blocking lenses for the prevention of eye diseases, in particular age-related macular degeneration (AMD). In humans, macular pigments (composed of lutein and zeaxanthin) represent a natural protection by filtering blue light, and can be increased through increased intake from foods or food supplements. These nutrients are associated with lower risk for AMD and cataract. Antioxidants such as vitamins C, E, or zinc might also contribute to the prevention of photochemical ocular damage by preventing oxidative stress. Currently, there is no evidence that LEDs in normal use at domestic intensity levels or in screen devices are retinotoxic to the human eye. However, the potential toxicity of long-term cumulative exposure and the dose-response effect are currently unknown.

Phenolic Acids and Amaryllidaceae Alkaloids Profiles in Leucojum aestivum L. In Vitro Plants Grown under Different Light Conditions.

Light-emitting diodes (LEDs) have emerged as efficient light sources for promoting in vitro plant growth and primary and secondary metabolite biosynthesis. This study investigated the effects of blue, red, and white-red LED lights on plant biomass growth, photosynthetic pigments, soluble sugars, phenolic compounds, the production of Amaryllidaceae alkaloids, and the activities of antioxidant enzymes in Leucojum aestivum L. cultures. A white fluorescent light was used as a control. The plants that were grown under white-red and red light showed the highest fresh biomass increments. The blue light stimulated chlorophyll a, carotenoid, and flavonoid production. The white-red and blue lights were favourable for phenolic acid biosynthesis. Chlorogenic, p-hydroxybenzoic, caffeic, syringic, p-coumaric, ferulic, sinapic, and benzoic acids were identified in plant materials, with ferulic acid dominating. The blue light had a significant beneficial effect both on galanthamine (4.67 µg/g of dry weight (DW)) and lycorine (115 µg/g DW) biosynthesis. Red light treatment increased catalase and superoxide dismutase activities, and high catalase activity was also observed in plants treated with white-red and blue light. This is the first report to provide evidence of the effects of LED light on the biosynthesis of phenolic acid and Amaryllidaceae alkaloids in L. aestivum cultures, which is of pharmacological importance and can propose new strategies for their production.

Low energy multiple blue light-emitting diode light Irradiation promotes melanin synthesis and induces DNA damage in B16F10 melanoma cells.

Visible light is present everywhere in our lives. Widespread use of computers and smartphones has increased the daily time spent in front of screens. What effect does this visible light have on us? Recent studies have shown that short-wavelength blue light (400-450nm) irradiation, similar to UV, inhibits the cell proliferation and differentiation, induces the intracellular oxidative stress, promotes the cell apoptosis and causes some other negative effects. However, it's unusual that directly face to such short-wavelength and high-energy blue light in daily life. Therefore, the effects of blue light with longer wavelength (470nm), lower energy (1, 2 J/cm2) and multiple times (simulated daily use) exposure on cells have been studied in this experiment. In our results, low energy density multiple blue light inhibited cell proliferation and metastatic capability with a weak phototoxicity. Blue light also promoted intracellular reactive oxygen species and caused DNA damage. Furthermore, the melanin synthesis was also promoted by low energy density multiple blue light exposure. Together, these results indicate that longer wavelength and low energy density blue light multiple exposure is still harmful to our cells. Furthermore, prolonged exposure to screens likely induces dull skin through induction of melanin synthesis. These results further mentioned us should paid more attention to controlling the daily use of digital device.

Blue LED light induces cytotoxicity via ROS production and mitochondrial damage in bovine subcutaneous preadipocytes

The purpose of this study was to investigate the effect and mechanism of blue light irradiation on bovine subcutaneous preadipocytes. In this study, preadipocytes were divided into dark group (control) and blue light group. Results show that blue light exposure time-dependently reduced the viability of preadipocytes and induced mitochondrial damage, in accompaniment with the accumulation of intracellular reactive oxygen species (ROS). Meanwhile, blue light caused oxidative stress, as evidenced by the increased MDA level, the reduced T-AOC contents, as well as the decreased activities of antioxidant enzymes. Additionally, blue light treatment induced apoptosis and G2/M phase arrest via Bcl-2/Bax/cleaved caspase-3 pathway and P53/GADD45 pathway, respectively. Protein expressions of LC3-II/LC3-I and P62 were up-regulated under blue light exposure, indicating blue light initiated autophagy but impeded autophagic degradation. Moreover, blue light caused an increase in the secretion of pro-inflammatory factors (TNF-α, IL-1β, and IL-6). Pretreatment with N-acetylcysteine (NAC), a potent ROS scavenger, restored the loss of mitochondrial membrane potential (Δψ) and reduced excess ROS. Additionally, the above negative effects of blue light on cells were alleviated after NAC administration. In conclusion, this study demonstrates blue light induces cellular ROS overproduction and Δψ depolarization, resulting in the decrease of cell viability and the activation of apoptosis, autophagy, and inflammation, providing a reference for the application of blue light in the regulation of fat cells in the future.

The combination of red and blue light increases the biomass and steroidal saponin contents of Paris polyphylla var. yunnanensis

Red and blue light regulate plant development and metabolism. Paris polyphylla var. yunnanensis, for which there is great demand, is a medicinal plant mainly distributed in China and other parts of Asia. However, the effects of red and blue light on the growth and metabolites of P. polyphylla var. yunnanensis remain unknown. This study evaluated the effects of red (R), blue (B), and red-blue composite light (1 R:1B, 2 R:1B, 3 R:1B) on plant growth and accumulation of steroidal saponins (polyphyllin I, II, VI, and VII) in P. polyphylla var. yunnanensis. The results showed that red and 2 R:1B light significantly increased the net photosynthetic rate and the fresh weight of P. polyphylla var. yunnanensis. Also the combined light, especially 3 R:1B, alleviated the damage to membrane lipid peroxidation in plants. Metabolomic analysis showed that different light treatments, especially 2 R:1B, significantly upregulated the levels of metabolites in metabolic pathways related to carbon and nitrogen balance, energy metabolism, and secondary metabolism in P. polyphylla var. yunnanensis leaves. Furthermore, 1 R:1B and 2 R:1B light treatments promoted the accumulation of steroidal saponins, such as polyphyllin I and VI in rhizomes of P. polyphylla var. yunnanensis. Based on the above results, the red-blue composite light (2 R:1B) could be considered as a suitable light treatment to increase the biomass and steroidal saponin contents of P. polyphylla var. yunnanensis.

Effects of blue LED irradiation on the quality characteristics of Mukeunji, a long‐term fermented kimchi, during refrigerated storage

AbstractThis study investigated the effects of blue light emitting diode (BLED) irradiation on the quality characteristics of Mukeunji (long‐term fermented kimchi). Mukeunji kimchi broth (MKB) was treated with 460 nm BLED (irradiance 375 J/s∙m2) under refrigerated storage conditions. The effects of BLED irradiation on microbial growth were evaluated over the 3‐day storage period at 4°C. The quality attributes of the MKB, including color, pH, and antioxidant activity, were also assessed during the storage period. No significant difference was observed in the viable counts of lactic acid bacteria between BLED‐treated and BLED‐untreated samples. The yeast and mold counts in the MKB, however, were significantly reduced after 24 hr of BLED treatment at 4°C. The MKB pH significantly increased after 72 hr of BLED treatment at 4°C. The hunter redness (a*) was retained in BLED‐treated samples, whereas the yellowness (b*) was reduced in all samples. After BLED irradiation for 24 hr, significant changes in the 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS) radical scavenging activity of the MKB were also observed. The MJ1 and MJ2 strains isolated from MKB showed high sequence homology with Bacillus paralicheniformis and Bacillus velezensis, respectively, with 99% similarity or more in the phylogenetic tree. Chlorophyll pigment absorbs the blue light emitted by the BLED, so it can partially reduce the growth inhibitory effect of BLED irradiation on the two isolates. These findings suggest that BLED treatment can potentially modulate microbiological growth in Mukeunji during refrigerated storage without significant detriment to its characteristic properties.

Biophotonic Effects of Low-Level Laser Therapy on Adipose-Derived Stem Cells for Soft Tissue Deficiency.

The objectives of this study are to use diode lasers for low-level laser therapy (LLLT) and to assess its applicability and effects in adipose-derived stem cell (ADSC) growth processes. Studies were conducted on the diode laser with wavelengths of 622.7, 527.1, and 467.3 nm. The mechanism of action of LLL illumination was studied on ADSCs, isolated from human tissue, and then cultured by examining different wavelengths to determine the relevant light parameters for optimal responses. We used enzyme-linked immunosorbent assay and real-time polymerase chain to determine the percentages of fibroblast-mediated procollagen type 1 and matrix metallopeptidase 1 (MMP-1), MMP-2, and MMP-9 production at different wavelengths. The levels of lactate dehydrogenase produced by ADSCs after LLL illumination were assessed as well. Clinical results from 20 patients treated for soft tissue deficiency were collected for assessment of ADSC-assisted lipotransfer. Low-level laser (622.7 nm) illumination on cell cultures in vitro increased ADSCs proliferation, type 1 procollagen expression, collagen production, as well as MMP-1, MMP-2, and MMP-9 relative expression. Statistical analysis demonstrated a significant difference in red light (622.7 nm) versus green light (527.1 nm) and blue light (467.3 nm, P < 0.05). No significant differences were noted between the effects of green and blue lights. In clinical application, all patients attained significant improvement with treatment in the final outcome assessment after 6 months. Low-level laser illumination may affect ADSCs growth processes and ADSC-assisted lipotransfer for soft tissue deformity, scar treatment, wound healing, and other reconstructive surgery.

Effect of Red and Blue Light on Cucumber Seedlings Grown in a Plant Factory

Light-emitting diodes (LEDs) have been regarded as the best artificial source of light for a plant factory. However, the effect of light quality on seedling production in such environments requires further study. On the basis of the practical application of light on cucumber seedlings (Ansha Company) in plant factories, the present investigation tracked and recorded the specific effects of red and blue light on the growth of the seedlings by analyzing the photo-biological mechanism involved. The growth parameters, as well as the photosynthetic characteristics of cucumber seedlings, were measured at different variations of light quality. The results showed that when the proportion of red light in the light source was higher than blue light, the height of the seedlings, leaf size, stem diameter, Dixon Quality Index (DQI), relative chlorophyll content, and the net photosynthetic rate were higher than those of the experimental group with a relatively high proportion of blue light. In the case of R7B3 (70% red light and 30% blue light), the stem diameter, DQI, and net photosynthetic rate of seedlings were 14%, 57%, and 22% higher than the minimum value, respectively. The present study analyzed the influence of red and blue light on plant growth characteristics during actual production and provides standardization for it.

Blue Light Regulates Cell Wall Structure and Carbohydrate Metabolism of Soybean Hypocotyl.

Soybean stem elongation and thickening are related to cell wall composition. Plant morphogenesis can be influenced by blue light, which can regulate cell wall structure and composition, and affect stem growth and development. Here, using proteomics and metabolomics, differentially expressed proteins and metabolites of hypocotyls grown in the dark and under blue light were studied to clarify the effects of blue light on the cell wall structure and carbohydrate metabolism pathway of soybean hypocotyls. Results showed that 1120 differential proteins were upregulated and 797 differential proteins were downregulated under blue light treatment, while 63 differential metabolites were upregulated and 36 differential metabolites were downregulated. Blue light promoted the establishment of cell wall structure and composition by regulating the expression of both the enzymes and metabolites related to cell wall structural composition and nonstructural carbohydrates. Thus, under blue light, the cross-sectional area of the hypocotyl and xylem were larger, the longitudinal length of pith cells was smaller, elongation of the soybean hypocotyl was inhibited, and diameter was increased.

Uticaj plave svetlosti iz prirodnih i veštačkih izvora na kožu

Blue light includes rays of lower energy in comparison to UV radiation, but it has a greater power of penetrating the dermis, even to a depth of 1mm. The aim of this review article was to analyze the biological effects of natural and artificial blue light on the skin based on the available literature, as well as to propose preventive measures in order to protect the skin from its harmful effects. The latest research has shown that blue light has various direct and indirect effects on the skin. The direct effects of blue light on the skin are the excessive creation of reactive oxygen species, nitrogen and hyperpigmentation, and it indirectly affects the skin by disrupting the circadian rhythm and secreting melatonin. Blue light has a direct effect on chromophores that are present in the skin and leads to their activation. Their activation leads to the excessive production of reactive oxygen species and release of reactive nitrogen species, that is, nitrogen monoxide (NO), which triggers melanogenesis and hyperpigmentation. Also, there comes to the decrease in cell vitality and/or proliferation of keratinocytes and melanocytes, then increased synthesis of pro-inflammatory interleukins and tumor necrosis factor alpha and altered collagen metabolism. Blue light reduces the antioxidative protection of the skin by causing the degradation of present carotenoids. It can be used in clinical practice in the prevention and treatment of certain dermatoses, as well as in photorejuvenation treatments in aesthetic medicine. Further research in this field is necessary.