UV-B Radiation Research Articles

A novel microcapsule composite Spherulites Peony Superior Retinol mitigates UVB-induced skin damage invitro and invivo.

Skin serves as our outermost barrier, protecting our bodies from various environmental damages. Increasing research has revealed that UVB is a primary factor for extrinsic aging. This study explored the role of a novel microcapsule composite Spherulites Peony Superior Retinol (SPSR) on skin damage induced by UVB. SPSR exhibited a capacity to eliminate UVB-induced ROS. By measurement of cyclobutane pyrimidine dimers (CPD) and comet assay, the results implied that SPSR mitigates DNA damage from oxidative damage caused by UVB. In addition, UVB radiation typically leads to an increase in inflammatory factors within the skin. Decreased gene expressions of interleukin-1α and TNF-α have been observed in HaCaT cells. Moreover, a decreased gene expression of extracellular matrix (ECM)-related protein, including fibronectin (FN1), Col1A1, and Col3A1 caused by UVB was mitigated by SPSR. Furthermore, the clinical trials with 30 volunteers confirmed the significant relief and antiwrinkle effects of the cosmetic formulation containing 0.1% SPSR. These findings implied the promising potential of SPSR as a comprehensive solution for combating the detrimental effects of UVB exposure and maintaining skin health.

Adaptive Divergence and Functional Convergence: The Evolution of Pulmonary Gene Expression in Amphibians of the Qingzang Plateau.

The Qingzang Plateau, with its harsh environmental conditions-low oxygen, high ultraviolet radiation and significant temperature fluctuations-demands specialised adaptations for survival. While genetic adaptations have been extensively studied, gene expression's role in amphibian adaptation to high elevations remains understudied. This study analysed pulmonary gene expression in 119 amphibians across the plateau to explore how genetic and environmental factors shape expression evolution. Transcriptomic analyses revealed significant interspecies variation, driven by environmental factors like temperature, oxygen levels, UVB radiation and precipitation. Principal Component and Mantel analyses found no significant correlation between gene expression divergence and genetic distance. Instead, species-specific traits and environmental pressures were pivotal in shaping expression patterns. PERMANOVA analysis showed environmental factors had varying impacts on species. For instance, Bufo gargarizans exhibited a strong gene expression response to multiple environmental factors, while Scutiger boulengeri was less influenced, reflecting diverse adaptive strategies. Functional enrichment analysis highlighted convergence in key biological processes, such as energy metabolism, apoptosis and autophagy, despite species-specific gene expression differences. These processes are critical for surviving the plateau's extremes. The findings suggest that gene expression evolution in amphibians on the Qingzang Plateau is shaped by both genetic diversity and environmental pressures. Although gene expression profiles vary, they converge on essential functions, offering insights into adaptation mechanisms in extreme environments.

Inoculation of methylotrophs mitigates heat and UV stress in mung bean (Vigna radiata L.) and enhances growth, antioxidant, and functional diversity.

Climate change involves the induction of heat and solar ultraviolet (UV) radiation, which profoundly affects sustainable crop production. Increasing solar UV radiation negatively impacts the photosynthetic apparatus, plant-associated organisms, and plant health. The present study aimed to comprehensively assess methylotrophic bacteria to alleviate heat and UV radiation in Vigna radiata L. under pot studies and field conditions. Under normal and UVB stress conditions, inoculation of methylotrophs significantly enhanced seed germination (72.55%-96.70% (normal)and 51.67%-65.33% (stressed)) and improved plant growth parameters, total chlorophyll (25.80-48.16 mg/g (normal) and 9.13-27.88 mg/g (stressed)), and carotenoid (569.1-1067.1 μg/g (normal)and 287.8-903.4 μg/g (stressed)) contents. A similar enhancement in antioxidant properties such as superoxide dismutase (1-5 fold), peroxidase (1-9 fold), phenylalanine ammonia lyase (1-4 fold), and proline content (1-5 fold) was observed in response to UVB radiation and heat stress under pot studies. A community-level physiological profile (CLPP) study of leaf samples revealed enhanced AWCD in methylotrophs treated plants compared to the UVB-exposed controls. Furthermore, field studies in summer conditions confirmed that inoculation with methylotrophs had a positive effect on V. radiata growth and physiology. The methylotrophs inoculation increased pod formation (25.44-32.78 and 15.56-32.00) and yield (109.81-238.63 and 71.88-216.29 q/ha) under UV cut-off sheet covered and non-covered conditions, respectively. This study demonstrated the potential of methylotrophs to mitigate heat and solar (UV) radiation in plants and provide sustainable strategies for agriculture and the environment.

BBX22 enhances the accumulation of antioxidants to inhibit DNA damage and promotes DNA repair under high UV-B.

Under changing climatic conditions, plant exposure to high-intensity UV-B can be a potential threat to plant health and all plant-derived human requirements, including food. It's crucial to understand how plants respond to high UV-B radiation so that proper measures can be taken to enhance tolerance towards high UV-B stress. We found that BBX22, a B-box protein-coding gene, is strongly induced within one hour of exposure to high-intensity UV-B. Our metabolomics data indicated that BBX22 promotes the accumulation of antioxidants like ascorbic acid and proline. These antioxidants play a vital role in shielding plants exposed to high UV-B from the detrimental effects of Reactive Oxygen Species (ROS), including DNA damage. Additionally, BBX22 promotes DNA damage repair by inducing the expression of DNA repair genes like UVR1 and UVR3. BBX22 directly binds to the promoter of UVR1 to regulate its expression. Furthermore, BBX22 indirectly induces the expression of UVR1 and UVR3 by enhancing the binding of HY5 to their promoters. Together, these results suggest a multi-pronged role of BBX22 in protection against high-intensity UV-B. Enhancing BBX22 levels or its orthologs in different plant species can potentially offer DNA damage protection and tolerance against intense UV radiation.

Formulation and evaluation of sunscreen spray gel with lime peel extract (Citrus aurantifolia)

Background: Prolonged exposure to sunlight poses detrimental effects on the skin. Lime peel extract, containing over 60% flavonoids, demonstrates significant potential as a sunscreen agent due to the presence of conjugated aromatic benzene rings capable of absorbing UV-A and UV-B radiation. To mitigate sun-induced skin damage, lime peel extract has been formulated into a spray gel, offering rapid drying properties that enhance user convenience and comfort during application. Objective: To evaluate the impact of varying concentrations of lime peel extract in sunscreen spray gel formulations on their physical properties and in vitro sun protection factor (SPF) values. Methods: Lime peel crude extract was obtained using 70% ethanol as the extraction solvent. The extract was incorporated into sunscreen spray gel formulations at concentrations of 5% (F1), 10% (F2), and 15% (F3). These formulations were assessed for their physical properties, including pH, viscosity, spreadability, drying time, and adhesion, alongside their in vitro SPF values. Results: The concentration of lime peel extract significantly influenced both the physical properties and SPF values of the spray gel formulations. All formulations (F1, F2, and F3) exhibited satisfactory physical stability and met the quality criteria for spray gel preparations. The SPF values for F1, F2, and F3 were determined to be 15, 20, and 30, respectively, indicating a progressive increase in photoprotective efficacy with higher extract concentrations. Conclusion: The sunscreen spray gel formulations containing lime peel extract at concentrations of 5% (F1), 10% (F2), and 15% (F3) demonstrated physical stability and provided moderate to high SPF protection. Among the formulations, F3 (15%) exhibited the highest SPF value of 30, suggesting its superior efficacy as a sunscreen agent.

Humic substances modulate bacterial communities and mitigate adverse effects of temperature stress in coral reef organisms.

In the present study, we tested if terrestrially-derived humic substances (HS) could mitigate the adverse effects of elevated temperature and UVB radiation on the bacterial communities of two hard corals (Montipora digitata and Montipora capricornis), one soft coral (Sarcophyton glaucum), sediment and water. We also examined the impact of temperature, UVB radiation and HS supplementation on coral photosynthetic activity, a proxy for coral bleaching. We performed a multifactorial experiment using a randomized-controlled microcosm setup. Coral photosynthetic efficiency was measured in vivo using a pulse amplitude modulation (PAM) fluorometer. Bacterial communities were analyzed using 16s rRNA gene sequencing. Corals in HS-supplemented microcosms had significantly higher photosynthetic activities than those in microcosms subjected to elevated temperature and UVB radiation. Additionally, HS supplementation significantly influenced the composition of sediment, water and host-associated bacterial communities. Reef organisms in HS supplemented microcosms contained distinct bacterial communities enriched with groups of potentially beneficial bacteria. In the hard coral Montipora digitata, we observed an interactive effect of HS supplementation, UVB radiation, and temperature. Our findings indicate that HS significantly modulates coral reef bacterial communities and support the hypothesis that these substances contribute to improved reef resistance to the adverse effects of elevated temperature and UVB radiation.

MaPac2, a Transcriptional Regulator, Is Involved in Conidiation, Stress Tolerances and Pathogenicity in Metarhizium acridum

The Gti1/Pac2 protein family, which is highly conserved across fungi, is pivotal in processes such as fungal development, spore formation, protein export, toxin production, and virulence. Despite its importance, the precise functions of Pac2 within entomopathogenic fungi have yet to be fully understood. In our study, the MaPac2 gene from M. acridum was identified, and its functions were explored. Studying the domain of the protein showed that MaPac2 comprises 422 amino acids with a characteristic Gti1/Pac2 family domain (Pfam09729). Additionally, MaPac2 is predicted to have an N-terminal protein kinase A phosphorylation site and a potential cyclin-dependent kinase phosphorylation site, highlighting its potential regulatory roles in the fungus. Our findings indicate that the inactivation of MaPac2 resulted in faster germination of conidia and a marked reduction in conidial production. Furthermore, stress tolerance tests revealed that the absence of MaPac2 significantly bolstered the fungal resilience to UV-B radiation, heat shock, SDS exposure, and stresses induced by hyperosmotic conditions and oxidative challenges. Virulence assessments through bioassays indicated no substantial differences among the WT, MaPac2-disrupted strain, and CP strains in the topical inoculation trials. Interestingly, deletion of MaPac2 increased the fungal virulence by intrahemocoel injection. Furthermore, we found that disruption of MaPac2 impaired fungal cuticle penetration due to the diminished appressorium formation but increased the fungal growth in locust hemolymph. These findings provide further insights into the roles played by Gti1/Pac2 in insect pathogenic fungi.

Climate Change and Plant Foods: The Influence of Environmental Stressors on Plant Metabolites and Future Food Sources

Climate change is reshaping global agriculture by altering temperature regimes and other environmental conditions, with profound implications for food security and agricultural productivity. This review examines how key environmental stressors—such as extreme temperatures, water scarcity, increased salinity, UV-B radiation, and elevated concentrations of ozone and CO2—impact the nutritional quality and bioactive compounds in plant-based foods. These stressors can modify the composition of essential nutrients, particularly phytochemicals, which directly affect the viability of specific crops in certain regions and subsequently influence human dietary patterns by shifting the availability of key food resources. To address these challenges, there is growing interest in resilient plant species, including those with natural tolerance to stress and genetically modified variants, as well as in alternative protein sources derived from plants. Additionally, unconventional food sources, such as invasive plant species and algae, are being explored as sustainable solutions for future nutrition.

Impact of Ultraviolet Radiation on Growth, Development and Antioxidant Enzymes of Tuta absoluta (Meyrick)

Ultraviolet radiation serves as a significant abiotic stressor for numerous organisms, particularly impacting insects in various ways. Tuta absoluta, a highly destructive pest infesting of the Solanaceae species, was investigated to elucidate its growth, development, and enzymatic defense mechanisms of insects in response to UV exposure. This study investigates the effects of three types of UV radiation on the lifespan, egg laying behavior, and antioxidant enzyme activities of T. absoluta. Our study revealed a significant reduction in the lifespan of T. absoluta upon exposure to both UV-A and UV-B radiation, whereas extended exposure to UV-C radiation for 120 min and 180 min resulted in a decline in its egg laying capacity. Exposure to all three types of radiation (UV-A, UV-B, and UV-C) led to an irreversible decrease in catalase (CAT) enzyme activity. Upon exposure to UV-A, there was a gradual increase in peroxidase (POD) enzyme activity; however, at 120 min post-exposure, a subsequent decrease was observed. A notable elevation in superoxide dismutase (SOD) activity was observed following exposures of both 60 min and 120 min durations under the rays of UV-A. These findings provide valuable insights into understanding the effects of UV exposure on T. absoluta as well as its potential application as a control measure, warranting further investigation.

Extraction of lignin from Duabanga grandiflora and its valorization for nanocomposite development with enhanced mechanical and UV shielding properties

Abstract In this study, we report on extracting lignin (EL) from Duabanga grandiflora (Khukon), an untapped wood source, and its transformation into nano-lignin (NL) to create durable and thermally stable composites. Utilizing ultrasonication, we synthesized spherical lignin nanoparticles with an average size of 8 nm, as verified by High-Resolution Transmission Electron Microscopy (HRTEM). These nanoparticles were integrated into a polyvinyl alcohol (PVA) and guar gum (GG) matrix, resulting in PVA-GG-nano-lignin (PGNL) composites. Polyvinyl alcohol (PVA)-Guar gum (GG) nanocomposite films containing various contents of lignin nano-particles (1, 2 and 3 wt%) were formulated by a simple solvent cast method and cross-linked by adding borax. Addition of 1wt% lignin nanoparticles brought in the composite films with 29.8MPa tensile strength and 139.3% elongation at break. Compared to PVA-GG-lignin (PGL) composites, the PGNL composites exhibited a 59.4% increase in tensile strength and enhanced elongation at break and good thermal degradation properties. Notably, the PGNL composite films were transparent but could shield 99.9% of the UV-A (320-400 nm) and UV-B (280-320 nm) radiations, marking a significant advancement in UV protective materials. Our innovative use of Duabanga grandiflora-derived nano-lignin in a dual-polymer network not only underscores the potential of renewable resources in high-performance applications but also aligns with the principles of a circular bioeconomy by offering a sustainable solution for effective UV protection.

Illuminating the Connection: Cutaneous Vitamin D3 Synthesis and Its Role in Skin Cancer Prevention

Sunlight exposure plays an important role in human health, impacting processes such as mood, blood pressure regulation, and vitamin D3 production. Solar ultraviolet B radiation initiates vitamin D3 synthesis in the skin, which is subsequently metabolized into its biologically active form. UVB exposure plays a key role in enabling vitamin D3 synthesis, but it can also contribute to skin carcinogenesis, creating a complex interplay between its beneficial and harmful effects. Vitamin D deficiency, affecting over half the global population, is linked to a range of chronic diseases, including cancers, cardiovascular conditions, and autoimmune disorders. Simultaneously, excessive solar UVB exposure increases the risk of non-melanoma and melanoma skin cancers through mechanisms involving DNA damage and oxidative stress. This review examines the dual role of UVB radiation in health and disease, focusing on the mechanisms of cutaneous vitamin D3 synthesis, the epidemiology of skin cancer, and the protective roles of vitamin D3’s photoproducts and its active metabolite, 1,25-dihydroxyvitamin D3. Understanding these interconnections is critical for developing strategies that balance adequate sun-induced vitamin D3 production with skin cancer prevention.

Impact of Vitamin D on Skin Aging, and Age-Related Dermatological Conditions.

Human skin is a physical and biochemical barrier that protects the internal body from the external environment. Throughout a person's life, the skin undergoes both intrinsic and extrinsic aging, leading to microscopic and macroscopic changes in its morphology. In addition, the repair processes slow with aging, making the older population more susceptible to skin diseases. Intrinsic factors associated with advanced age gradually degrade the dermal collagen matrix, resulting in fine wrinkles and reduced elasticity; this is accelerated in post-menopausal women due to estrogen deficiency. In contrast, extrinsic factors associated with advanced age, primarily caused by exposure to ultraviolet (UV) radiation, lead to coarse wrinkles, solar elastosis, hyperkeratosis, irregular pigmentation, and skin cancers. UVB radiation, while contributing to skin photo-aging, also induces the cutaneous synthesis of vitamin D. Vitamin D, in turn, protects the skin from oxidative stress, inflammation, and DNA damage, thereby delaying both chronological and photo-aging. Moreover, research has demonstrated an association between lower vitamin D levels and a higher prevalence of certain cutaneous diseases. This review explores and summarizes the critical role of vitamin D in skin aging and age-related skin diseases. The data presented highlight the importance of maintaining vitamin D adequacy throughout life.

The repair effects of cerium oxide nanoparticles on enhanced UV-B radiation in mung bean (Vigna radiata) seedling roots

The repair effects of cerium oxide nanoparticles on enhanced UV-B radiation in mung bean (Vigna radiata) seedling roots

Algae extract-based nanoemulsions for photoprotection against UVB radiation: an electrical impedance spectroscopy study

Skin cancer is one of the most common types of cancer worldwide, with exposure to UVB radiation being a significant risk factor for its development. To prevent skin cancer, continuous research efforts have focused on finding suitable photoprotective ingredients from natural sources that are also environmentally friendly. This study aimed to develop oil-in-water photoprotective nanoemulsions containing marine macroalgae extract. A Box–Behnken experimental design was used to identify the most promising formulation composition, resulting in optimal physical properties. These properties, including droplet size, polydispersity index (PDI), and zeta potential, were evaluated using dynamic light scattering (DLS). To assess the photoprotection capacity of the formulations, electrical impedance spectroscopy (EIS) was employed to evaluate alterations in the electrical characteristics of excised pig skin membranes placed in Franz cells equipped with a 4-electrode set-up. The final composition of the nanoemulsion was caprylic/capric triglycerides 4%, Macrogolglycerol ricinoleate 30%, and algae extract 1%. The nanoemulsions had an average droplet size of 128.5 ± 8.6 nm, a PDI of 0.25 ± 0.06, and a zeta potential of 45.14 ± 0.02 mV. Compared to the control group, the photoprotective capacity of the oil-in-water nanoemulsions was statistically significant. Specifically, only a 15% reduction in the skin membrane electrical resistance following UVB exposure was observed when the formulation containing algae extract was used, whereas a 50% reduction was observed for the vehicle. In conclusion, this work demonstrates that the developed nanoemulsions based on natural ingredients show promising protective capacity against UVB exposure of the skin.

Balancing the solar irradiance needs: optimising growth in sphagnum palustre through tailored UV-B effects

BackgroundThe carbon sequestration potential and water retention capacity of peatlands are closely linked to the growth dynamics of Sphagnum mosses. However, few studies have focused on the response of Sphagnum moss growth dynamics to UV-B radiation, and existing research has emphasized species differences. In this study, Sphagnum palustre L., a dominant species in the peatlands of Southern China, was selected as a research subject, and its response to UV-B radiation has not been reported before.ResultsIn the field, the morphology and growth differences of Sphagnum palustre under microhabitats with varying UV-B radiation intensities were monitored. Our findings revealed that the height of Sphagnum palustre increased the most in the microhabitats (Juncus community) with the weakest UV-B radiation, however the capitate branch area and biomass of Sphagnum palustre were highest under the Fern community, where UV-B radiation was attenuated by 50% during the summer. In the laboratory, we established four levels of UV-B radiation treatments: 0 MJ/m2/d (control group, no UV-B radiation), 0.2 MJ/m2/d (low UV-B radiation), 0.4 MJ/m2/d (middle UV-B radiation), and 0.8 MJ/m2/d (high UV-B radiation). We investigated the effects of UV-B radiation intensity on the morphology, biomass, and water-holding capacity of Sphagnum palustre after exposing it to UV-B radiation for 30 days. Results indicated that low UV-B radiation (0.2 MJ/m2/d) significantly enhanced the growth of Sphagnum palustre. The capitulum area, plant height, capitulum biomass, and individual biomass of Sphagnum palustre increased by 14.60%, 1.27%, 10.98%, and 16.49%, respectively, compared to the control. Additionally, the maximum water absorption rate of Sphagnum palustre reached 4515.44%. In contrast, under high UV-B radiation (0.8 MJ/m²/d), these indicators significantly decreased, while the water loss rate significantly increased.ConclusionThis study suggests that the intensity of UV-B radiation can be artificially regulated to optimize the growth of Sphagnum, accelerate peatland restoration, and enhance the yield of artificially cultivated Sphagnum moss.

Unraveling TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR Transcription Factors in Safflower: A Blueprint for Stress Resilience and Metabolic Regulation.

Safflower (Carthamus tinctorius L.), a versatile medicinal and economic crop, harbors untapped genetic resources essential for stress resilience and metabolic regulation. The TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) transcription factors, exclusive to plants, are pivotal in orchestrating growth, development, and stress responses, yet their roles in safflower remain unexplored. Here, we report the comprehensive identification and characterization of 26 safflower TCP genes (CtTCPs), categorized into Class I (PROLIFERATING CELL FACTOR, PCF) and Class II (CINCINNATA and TEOSINTE BRANCHED1/CYCLOIDEA, CIN and CYC/TB1) subfamilies. Comparative phylogenetics, conserved motif, and gene structure analyses revealed a high degree of evolutionary conservation and functional divergence within the gene family. Promoter analyses uncovered light-, hormone-, and stress-responsive cis-elements, underscoring their regulatory potential. Functional insights from qRT-PCR analyses demonstrated dynamic CtTCP expression under abiotic stresses, including abscisic acid (ABA), Methyl Jasmonate (MeJA), Cold, and ultraviolet radiation b (UV-B) treatments. Notably, ABA stress triggered a significant increase in flavonoid accumulation, correlated with the upregulation of key flavonoid biosynthesis genes and select CtTCPs. These findings illuminate the complex regulatory networks underlying safflower's abiotic stress responses and secondary metabolism, offering a molecular framework to enhance crop resilience and metabolic engineering for sustainable agriculture.

New insight into the role of the pathway NLRP1 and NLRP3 inflammasomes and IL-33 in ultraviolet-induced cutaneous carcinogenesis.

Inflammasomes NLRP1 (NLR family pyrin domain containing 1) and NLRP3 are pivotal regulators of the innate immune response, activated by a spectrum of endogenous and exogenous stressors, including ultraviolet radiation (UVR). The precise molecular mechanisms underlying the activation of these inflammasomes remain unclear. Furthermore, the involvement of interleukin-33 (IL-33) in UVR-induced skin carcinogenesis is not well defined. The objective of this study is to evaluate the expression of interleukin genes (IL-33, IL-18, IL-1β) following the activation and silencing of NLRP1 and NLRP3 at various wavelengths and doses of UV radiation, and to correlate these expressions with pertinent tumor markers (e.g., Gli1, Gli2, FOXO3A, SerpinA1, SerpinA3, and EphB2). Cultures of keratinocyte cell lines were exposed to varying doses of UV radiation using specific lamps. To inhibit the expression of NLRP1 and NLRP3 genes, cells were transfected with targeted siRNAs. Gene expression of inflammasome components and effector proteins was quantified using Real-time PCR and ELISA. There was a marked upregulation in the expression levels of cytokine genes IL-18, IL-1β, and IL-33 upon exposure to UVB and UVA radiation, compared to non-irradiated keratinocytes. Silencing NLRP1 or NLRP3 via RNA interference in primary human keratinocytes resulted in a significant reduction of cytokine gene expression. Additionally, a notable increase in tumor marker gene expression was observed in cells with functional NLRP1 and NLRP3 following UV radiation, whereas silencing these inflammasome genes altered the expression profiles of these markers. This study provides a pioneering comprehensive assessment of the roles of NLRP1, NLRP3, and IL-33 in the pathogenesis of UV-induced cutaneous carcinogenesis. Our findings substantiate the role of IL-33 as a critical early danger signal elicited in response to inflammatory UV radiation, presumably regulated by inflammasomes.

WRKY Transcription Factors Modulate the Flavonoid Pathway of Rhododendron chrysanthum Pall. Under UV-B Stress.

The depletion of the ozone layer has resulted in elevated ultraviolet-B (UV-B) radiation levels, posing a significant risk to terrestrial plant growth. Rhododendron chrysanthum Pall. (R. chrysanthum), adapted to high-altitude and high-irradiation environments, has developed unique adaptive mechanisms. This study exposed R. chrysanthum to UV-B radiation for two days, with an 8 h daily treatment, utilizing metabolomic and transcriptomic analyses to explore the role of WRKY transcription factors in the plant's UV-B stress response and their regulation of flavonoid synthesis. UV-B stress resulted in a significant decrease in rETR and Ik and a significant increase in 1-qP. These chlorophyll fluorescence parameters indicate that UV-B stress impaired photosynthesis in R. chrysanthum. Faced with the detrimental impact of UV-B radiation, R. chrysanthum is capable of mitigating its effects by modulating its flavonoid biosynthetic pathways to adapt positively to the stress. This study revealed changes in the expression of 113 flavonoid-related metabolites and 42 associated genes, with WRKY transcription factors showing significant correlation with these alterations. WRKY transcription factors can influence the expression of key enzyme genes in the flavonoid metabolic pathway, thereby affecting metabolite production. A theoretical reference for investigating plant stress physiology is provided in this work, which also offers insights into the stress responses of alpine plants under adverse conditions.

Photoprotection and antioxidant activity of eumelanin from Streptomyces lasalocidi NTB 42 and its photoprotective effects on Schizosaccharomyces pombe ARC039.

This study evaluated the photoprotective and antioxidant properties of eumelanin derived from Streptomyces lasalocidi NTB 42 (eumelanin NTB 42). This study also investigated the cellular-level photoprotective effects of eumelanin using Schizosaccharomyces pombe ARC039 as a model organism and its ability to enhance the Sun Protection Factor (SPF) of commercial sunscreens. The thermal and light stability and total phenolic and flavonoid contents were analyzed. Antioxidant activity was assessed using hydroxyl radicals (OH), and superoxide anions (O2.-) radical-scavenging assays. The efficacy of photoprotection was determined using various in vitro methods, yeast cell viability assays, and enhanced SPF values of commercial sunscreen products. Eumelanin NTB 42 exhibited both thermal and photostabilities. The total phenolic and flavonoid contents were reported as 88.82±0.68mg gallic acid equivalent (GAE)/g and 53.24±2.66mg quercetin equivalent (QE)/g, respectively, representing the first report on microbial eumelanin. Eumelanin NTB 42 demonstrated significant scavenging activity against OH and O2.-. It also displays notable photoprotective effects against UV-B radiation, offering broad-spectrum coverage and optimal protection against UV-A radiation. It effectively acted as a sunblock against UV-A and UV-B radiation. Furthermore, eumelanin NTB 42 enhanced S. pombe ARC039 cell viability after exposure to UV-B and UV-C for 30-90min. It also augmented the SPF value of commercial products at a minimum concentration of 0.0025%. These findings highlight the potential antioxidant and photoprotective properties of eumelanin NTB 42, suggesting its applicability as a raw material for sunscreen formulations in the cosmetic industry.

Antioxidant and membrane-protective effects of the 3-O-ethyl ascorbic acid-cannabigerol system on UVB-irradiated human keratinocytes.

The lack of effective protection against UVB radiation, that severely disrupts the metabolism of keratinocytes, underlines the search for bioactive compounds that would provide effective protection without causing side effects. Therefore, the aim of the study has been to assess the effect of two compounds, that are different in terms of structure and properties: 3-O-ethyl ascorbic acid-EAA (a stable derivative of vitamin C) and cannabigerol-CBG, used separately or concurrently, on the metabolism of keratinocytes previously exposed to UVB. The obtained results indicate diverse, yet mutually reinforcing localization of the tested compounds, both within the membrane structures and cytosol. When used concurrently, EAA+CBG effectively prevent modifications of the structure of cell membranes, particularly the increase in their fluidity and permeability caused by UVB. It promotes cell survival and enhances the expression of membrane transporters, especially BCRP. Moreover, the concurrent use of both compounds, by reducing the level of ROS and regulating the expression of both Nrf2 activators (p62, MAPK) and inhibitors (Keap1, Bach1, PAGM5), supports the antioxidant efficiency of cells, visible in the increased activity of antioxidant enzymes (SOD1/2, CAT) and the effectiveness of GSH- and Trx-dependent antioxidant systems. Consequently, oxidative modifications of lipids (assessed as 4-HNE and isoprostanes) and proteins (measured as 4-HNE-protein adducts and carbonyl groups) are reduced. The tested compounds also reveal anti-inflammatory effects by modifying the expression of the activator (p62) and inhibitors (IKKα, IKKβ) of NFκB. The observed EAA+CBG effect in preventing changes in the structure and functionality of keratinocyte membranes, maintaining redox balance, and mitigating inflammatory effects caused by UVB provides the basis for further research.