Toxic effects of ultraviolet radiation on the skin

Photoinitiated Nitric Oxide Release as an Antibacterial Treatment for Chronic Wounds

Taking advantage of their innate roles as antibacterial strategies, the dual activity of photobiomodulation (PBM) and nitric oxide (NO) was combined to provide a tunable, on-demand chronic wound therapeutic. S-nitrosothiol-modified mesoporous silica nanoparticles (RSNO-MSNs) were doped into polyurethane (PU) to demonstrate preliminary utility as an antibacterial wound dressing treatment for chronic wounds. Photoinitiated and resultant NO-release kinetics and payloads were evaluated at 405, 430, and 530 nm for multiple irradiances. The use of photons and the NO-releasing MSNs against common chronic wound pathogens, such as Pseudomonas aeruginosa and Staphylococcus aureus, proved to be highly bactericidal. Cytocompatibility of the treatment was confirmed using human epidermal keratinocytes, a representative skin cell line.

Clinicopathological comparison of benign eyelid tumours in tertiary care centers in Lima and Montreal from 2010 to 2019

OBJECTIVE

The eyelids are complex structures composed of various tissues. As such, a wide array of lesions exist that affect the eyelids. Clinical diagnosis of these lesions is essential to differentiate benign from malignant ones. Although accurate, some cases are misdiagnosed. Histopathology remains the crucial step in the final diagnosis of eyelid lesions. The objective of the study is to describe and compare the clinicopathological diagnosis of benign eyelid tumours between two tertiary care centers, one in South America and the other in North America, from 2010 to 2019.

METHODS

We reviewed 1 935 tumours at the McGill University Health Centre (MUHC)-McGill University Ocular Pathology and Translational Research Laboratory and 1 256 tumours collected at "Dr. Jose Antonio Avendaño Valdez" Ocular Pathology at the Instituto Nacional de Oftalmologia Peru (INO) (2010-2019). Demographic information and clinical and histopathological diagnoses were collected in an anonymized fashion.

RESULTS

The average age was 61.04 years at MUHC and 47.44 years at INO, benign tumours accounted for 78.11 % and 79.84%, respectively. The three most frequent benign tumour were squamous cell papilloma, nevus, and seborrheic keratosis at both sites. Lesions most commonly affected the upper and lower eyelid. 2.32% at the MUHC and 1.35% at the INO of cases were clinically misdiagnosed as benign tumours but confirmed malignant by histopathology.

CONCLUSION

The most common lesions were squamous cell papilloma, nevus, and seborrheic keratosis, although the most common diagnosis varied, likely due to environmental factors differing at each site. Histopathology is essential for the accurate diagnosis of eyelid tumours.

A new era of psoriasis treatment: Drug repurposing through the lens of nanotechnology and machine learning

Psoriasis is a persistent inflammatory skin disorder characterized by hyper-proliferation and abnormal epidermal differentiation. Conventional treatments such as; topical therapies, phototherapy, systemic immune modulators, and biologics aim to relieve symptoms and improve patient quality of life. However, challenges like adverse effects, high costs, and individual response variability persist. Thus, the need for novel anti-psoriatic drugs has led to the exploration of drug repurposing, an approach that identifies new applications for existing drugs. This method is in its early stages but has gained popularity across both public and private sectors. Furthermore, artificial intelligence (AI) integration is revolutionizing the healthcare industry by enhancing efficiency, delivery, and personalization. Machine learning and deep learning algorithms have significantly impacted drug discovery, repurposing, and designing new molecules or drug delivery carriers. Nanotechnology, in addition to AI, plays a pivotal role in targeting repurposed drugs via the topical route with suitable nanocarriers. This method overcomes challenges associated with oral delivery, such as systemic toxicities, slow onset of action, first-pass effect, and poor bioavailability. This review addresses the practice of repurposing existing drugs for managing psoriasis, discussing the challenges of conventional therapy and how the incorporation of nanotechnology and AI can overcome these hurdles, facilitating the discovery of anti-psoriatic drugs and presenting promising strategies for novel therapeutics. Additionally, it discusses the general benefits of drug repurposing compared to de novo drug development and the potential drawbacks of drug repurposing.

Drug Repurposing and Nanotechnology for Topical Skin Cancer Treatment: Redirecting toward Targeted and Synergistic Antitumor Effects

Skin cancer represents a major health concern due to its rising incidence and limited treatment options. Current treatments (surgery, chemotherapy, radiotherapy, immunotherapy, and targeted therapy) often entail high costs, patient inconvenience, significant adverse effects, and limited therapeutic efficacy. The search for novel treatment options is also marked by the high capital investment and extensive development involved in the drug discovery process. In response to these challenges, repurposing existing drugs for topical application and optimizing their delivery through nanotechnology could be the answer. This innovative strategy aims to combine the advantages of the known pharmacological background of commonly used drugs to expedite therapeutic development, with nanosystem-based formulations, which among other advantages allow for improved skin permeation and retention and overall higher therapeutic efficacy and safety. The present review provides a critical analysis of repurposed drugs such as doxycycline, itraconazole, niclosamide, simvastatin, leflunomide, metformin, and celecoxib, formulated into different nanosystems, namely, nanoemulsions and nanoemulgels, nanodispersions, solid lipid nanoparticles, nanostructured lipid carriers, polymeric nanoparticles, hybrid lipid-polymer nanoparticles, hybrid electrospun nanofibrous scaffolds, liposomes and liposomal gels, ethosomes and ethosomal gels, and aspasomes, for improved outcomes in the battle against skin cancer. Enhanced antitumor effects on melanoma and nonmelanoma research models are highlighted, with some nanoparticles even showing intrinsic anticancer properties, leading to synergistic effects. The explored research findings highly evidence the potential of these approaches to complement the currently available therapeutic strategies in the hope that these treatments might one day reach the pharmaceutical market.

Nicotinamide: A Multifaceted Molecule in Skin Health and Beyond

Nicotinamide (NAM), the amide form of vitamin B3, is a precursor to essential cofactors nicotinamide adenine dinucleotide (NAD⁺) and NADPH. NAD⁺ is integral to numerous cellular processes, including metabolism regulation, ATP production, mitochondrial respiration, reactive oxygen species (ROS) management, DNA repair, cellular senescence, and aging. NAM supplementation has demonstrated efficacy in restoring cellular energy, repairing DNA damage, and inhibiting inflammation by suppressing pro-inflammatory cytokines release. Due to its natural presence in a variety of foods and its excellent safety profile-even at high doses of up to 3 g/day-NAM is extensively used in the chemoprevention of non-melanoma skin cancers and the treatment of dermatological conditions such as blistering diseases, atopic dermatitis, rosacea, and acne vulgaris. Recently, its anti-aging properties have elevated NAM's prominence in skincare formulations. Beyond DNA repair and energy replenishment, NAM significantly impacts oxidative stress reduction, cell cycle regulation, and apoptosis modulation. Despite these multifaceted benefits, the comprehensive molecular mechanisms underlying NAM's actions remain not fully elucidated. This review consolidates recent research to shed light on these mechanisms, emphasizing the critical role of NAM in cellular health and its therapeutic potential. By enhancing our understanding, this work underscores the importance of continued exploration into NAM's applications, aiming to inform future clinical practices and skincare innovations.

Balancing act: optimizing blue light for melanogenesis while minimizing cellular damage in primary human skin cells

Introduction

Recent findings show that visible light, particularly blue light, stimulates melanogenesis in human skin, though the underlying mechanisms remain debated. This study aimed to determine the cell damage threshold of non-ionizing blue light on keratinocytes while preserving their ability to stimulate melanogenesis.

Methods

Human keratinocytes (N = 3) and melanocytes (N = 3) were isolated from skin samples of varying Fitzpatrick skin phototypes and irradiated with blue light (λpeak = 457 nm) and UVA light (λpeak = 385 nm). Cellular metabolic activity was assessed using the AlamarBlue HS assay, α-Melanocyte-Stimulating Hormone (α-MSH) production by keratinocytes was quantified using ELISA, and Western blotting was used to assess pro-melanogenic factor expression in melanocytes.

Results

High blue light intensity (50 mW/cm2, 50 J/cm2) and UVA light (15 mW/cm2, 20 J/cm2) significantly reduced cellular metabolic activity, with a 0.86 ± 0.055 and 0.60 ± 0.031 (mean ± SD) fold decrease compared to their respective sham by day 7. In contrast, moderate blue light intensities (5-15 mW/cm2, 10-20 J/cm2) preserved cellular metabolic activity while stimulating α-MSH production, with an optimal balance achieved at 10 mW/cm2, 15 J/cm2 (1.14 ± 0.046 fold increase relative to sham on day 7). Co-culture experiments confirmed that irradiated keratinocytes enhanced melanogenesis in melanocytes via paracrine signaling, increasing the expression of Tyrosinase and Dopachrome Tautomerase (DCT). Direct blue light irradiation on melanocytes also increased pigmentation without significant cellular damage.

Discussion

Moderate-intensity blue light at 10 mW/cm2, 15 J/cm2 effectively stimulates melanogenesis while maintaining cellular metabolic activity in both keratinocytes and melanocytes, offering a promising, safe approach for blue light therapies targeting pigmentation disorders.

Mechanistic studies on protective effects of total flavonoids from Ilex latifolia Thunb. on UVB-radiated human keratinocyte cell line (HaCaT cells) based on network pharmacology and molecular docking technique

The aim of the present research is to investigate anti-UVB radiation activity of total flavonoids from Ilex latifolia Thunb. (namely large-leaved Kuding tea) on human keratinocyte cell line (HaCaT cells) based on network pharmacology and molecular docking technique. Network pharmacology was used to screen target genes of active ingredients from Ilex latifolia Thunb. associated with UVB irradiation. The possible signaling pathways were analyzed by KEGG enrichment and verified by cellular experiments. Molecular docking was used to assess the affinity between the active ingredients and the core targets. The prediction of network pharmacology and molecular docking was identified by series experiment in UVB-irradiated HaCaT cells. Network pharmacology results showed that the active ingredients of Ilex latifolia Thunb. for anti-UVB irradiation were mainly flavonoids, and the possible signaling pathways were involved in PI3K-AKT, apoptosis, MAPKs, NF-κB, and JAK-STAT3. Molecular docking indicated key binding activity between AKT1-Glycitein, STAT3-Formononetin, CASP3-Formononetin, TNF-Kaempferol, CASP3-Luteolin, and AKT1-Quercetin. The total flavonoid pretreatment (0.25-1.0 mg/mL) down-regulated the expression of IL-6, IL-1β, and TNF-α in the cells determined by ELISA. The expression of phosphor PI3K, phosphor AKT, phosphor JAK, phosphor STAT3, phosphor JNK, and phosphor p38 MAPKs and COX-2 proteins in cytosolic and NF-κB p65 protein in nucleus were down-regulated and determined by western blot. It also protected UVB-irradiated cells from apoptosis by reducing apoptosis rate and down-regulating active-caspase 3. In a word, the total flavonoid treatment protected HaCaT cells from UVB injuries effectively, and the potential mechanism involves PI3K-AKT, JAK-STAT3, MAPK, and NF-κB pathway by anti-inflammatory and apoptosis action in cells. The mechanism in vivo experiment needs to be further confirmed in future.

Stress-Driven Production of γ-Aminobutyric Acid Using Non-Conventional Yeast Strains Kluyveromyces marxianus JMY140K and Metschnikowia reukaufii JMY075

γ-Aminobutyric acid (GABA) is a valuable amino acid widely used in food, healthcare, and agriculture. GABA bioproduction by budding yeasts has been commonly reported, but related studies using non-conventional yeasts remain limited. In this study, two non-conventional natural yeast strains, namely, Kluyveromyces marxianus JMY140K and Metschnikowia reukaufii JMY075, were identified as promising GABA producers, and M. reukaufii JMY075 was discovered to be a GABA producer. Enhanced GABA production was observed in the two yeast strains under stress conditions, including high temperature and high ethanol and acetic acid levels. In particular, K. marxianus JMY140K showed 7.93 times higher GABA titers under thermal stress than that of the control. External stress conditions significantly influenced the GABA production of these two yeast strains. The culture filtrate of K. marxianus JMY140K also showed promising activities in human skin cells. In addition, K. marxianus JMY140K could also produce GABA using rice straw hydrolysate, which indicated that it has the potential to produce GABA using renewable biomass. Our studies provide insight for further enhancing the GABA production of natural yeasts and promoting its biotechnology applications.

Ultraviolet and infrared radiation in Australia: assessing the benefits, risks, and optimal exposure guidelines

Despite extensive research, determining the optimal level of sunlight exposure for human health remains a challenge, emphasizing the need for ongoing scientific inquiry into this critical aspect of human well-being. This review aims to elucidate how different components of the solar spectrum, particularly near-infrared (NIR) radiation and ultraviolet radiation (UVR) affect human health in diverse ways depending on factors such as time of day and duration of exposure. Sunlight has beneficial effects from the production of melatonin by NIR and vitamin D by UVB. Sunlight also causes harmful effects as evidenced by oxidative stress and DNA damage. Exposure to morning and evening sunlight when the UV index is below 3 is suggested to be beneficial for harnessing its positive effects while avoiding the harmful effects of UVR when the UV index is 3 or higher. Understanding the optimal timing and duration of sunlight exposure is crucial for harnessing its beneficial effects while minimizing its harmful consequences by adopting appropriate sun protection measures. By adhering to sun protection guidelines when the UV index is 3 or more and incorporating strategic exposure to NIR rays when the UV index is less than 3, individuals can optimize their health outcomes while mitigating the risks associated with sun exposure. Given that the effects of sun exposure can be both harmful and beneficial, and Australia's unique geographical position where it experiences the highest levels of exposure to sunlight, it is vital to understand the appropriate level and timing of sun exposure to live healthy under the Australian sun.

Non-Thermal Treatment Mediated by Curcumin for Enhancing Food Product Quality

Increasing antibiotic resistance is one of the world's greatest health problems, and biocide use in food disinfection, alongside other application fields, could increase antibiotic resistance. Effective and eco-friendly food decontamination treatment with minimal chemical intervention in food production is urgently needed. Synergistic antimicrobial interaction of photoactive compounds and blue-light-emitting diodes have recently been proven effective in agricultural and environmental applications. Curcumin-based non-thermal treatment has been reviewed in this work for the development of a safe and effective decontamination tool that could be adapted to the food industry. The antimicrobial mechanism of the synergistic interaction and the inhibitory efficacy against foodborne pathogens (bacteria in both vegetative form and spore, as well as in biofilms) are discussed. Further studies on curcumin and its derivative, as well as light illumination patterns, were compared for enhanced bactericidal efficacy. Moreover, studies relating to photodynamic inactivation treatment for food sanitation and food quality enhancement (cereal grains and other food products) were summarized, as well as the impact on food organoleptic and nutritional quality.

Protective Action of Curcumin and Alpha-lipoic Acid, Against Experimental Ultraviolet-A/B Induced Dermal-injury in Rats

The objective of this study was to examine the therapeutic efficacy of curcumin (CUR) and α-lipoic acid (ALA) in mitigating UV-A and UV-B-induced damage (UVAB) in rat dorsal skin. This was achieved through the utilisation of immunohistochemical (TUNEL), biochemical and stereological techniques. The rats in the UVAB, UVAB + CUR, and UVAB + ALA groups were subjected to UVAB irradiation for a period of two hours per day over the course of one month. The UVAB + CUR and UVAB + ALA groups were administered 100 mg/kg/day of curcumin and 100 mg/kg/day of α-lipoic acid via gavage 30 min prior to UVAB irradiation. The CUR group was administered 100 mg/kg/day of curcumin via gavage, while the ALA group received the same dose of α-lipoic acid. A significant change in the volume ratio of the dorsal skin epidermis and dermis was observed in the stereological findings of the rats in the UVAB group. These changes exhibited a favourable progression as a consequence of the CUR and ALA applications. In the UVAB group, TOS and OSI were significantly elevated as a consequence of the rise in oxidative stress. Conversely, the treatment groups demonstrated a notable reduction in TOS and OSI levels. The study also revealed a substantial increase in the number of apoptotic cells within the UVAB group. However, the treatment groups exhibited a significant decline in apoptotic cells. In conclusion, the findings suggest that CUR and ALA possess a protective effect against UVAB-induced skin damage.

Evaluating the Fluorescence Quenching of Troxerutin for Commercial UV Sunscreen Filters

2-Phenylbenzimidazole-5-sulfonic acid (PBSA) and disodium phenyl dibenzimidazole tetrasulfonate (DPDT) are commercially available ultraviolet (UV) sunscreen filters that are known to undergo radiative relaxation following the absorption of UV light. The release of high-energy photons from this relaxation can be detrimental to human health; therefore, fluorescence quenchers need to be incorporated in commercial sunscreen formulations containing PBSA or DPDT. Troxerutin is a fluorescence quencher utilized for DPDT commercially. Here, its ability to quench the fluorescence of both PBSA and DPDT is evaluated using a dual-pronged approach by breaking down the multicomponent problem into its constituent parts. First, PBSA and DPDT's femtosecond to nanosecond photodynamics are uncovered in solution and on the surface of a human skin mimic to ascertain a benchmark. Second, these results are compared to their photodynamics in the presence of troxerutin. A significant reduction in the fluorescence lifetime is observed for both PBSA and DPDT on a human skin mimic with the addition of troxerutin, which is attributed to a Dexter energy transfer (DET) or Förster resonance energy transfer (FRET) quenching mechanism. This finding demonstrates the hitherto unseen fluorescence quenching mechanism of troxerutin on a human skin mimic and its role in quenching the fluorescence of commercial UV sunscreen filters through a DET or FRET mechanism.

Effect of Ceramides Derivatives from the Peach on Skin Function Improvement in UV-Irradiated Hairless Mice

This study investigated the protective effects of a ceramides derivates from the peach (PF3) on photoaging by UV-irradiated hairless mice. Mice were randomly divided into seven groups: AIN93G without UVB exposure (normal control, NC), AIN93G with UVB exposure (control, C), AIN93G supplemented 100 mg/kg body weight (BW) of L-ascorbic acid with UVB exposure (AA), AIN93G supplemented 100 mg/kg BW of arbutin with UVB exposure (Arbutin), AIN93G supplemented 10 mg/kg BW of PF3 with UVB exposure (10PF3), AIN93G supplemented 20 mg/kg BW of PF3 with UVB exposure (20PF3), and AIN93G supplemented 40 mg/kg BW of PF3 with UVB exposure (40PF3). The study examined the impact of PF3 on skin hydration, wrinkle formation, and melanogenesis using enzyme-linked immunosorbent assay (ELISA), real-time polymerase chain reaction (real-time PCR), and Western blot analysis. The PF3 demonstrated significant protective effects against photoaging by reducing skin wrinkle formation, decreasing epidermal and dermal thickening, and improving skin hydration. It also enhanced the expression of moisture-related factors (hyaluronic acid synthase [HAS], long-chain ceramides [LCBs], dihydroceramide desaturase 1 [DEGS1], and type I collagen [COL1A]) and antioxidant enzyme activities while reducing pro-inflammatory cytokines and oxidative stress markers. The PF3 supplementation positively modulated skin wrinkle formation-related factors, increasing collagen-related gene expression and decreasing matrix metalloproteinases. Additionally, PF3 showed potential in regulating melanogenesis by reducing the nitric oxide and cAMP content, as well as the expression of melanogenesis-related proteins. These comprehensive findings suggest that PF3 supplementation may be an effective strategy for preventing and treating UVB-induced skin photoaging through multiple mechanisms, including improved skin structure, hydration, antioxidant defense, and reduced inflammation and pigmentation.

Silibinin-Loaded Liposomes: The Influence of Modifications on Physicochemical Characteristics, Stability, and Bioactivity Associated with Dermal Application

BACKGROUND/OBJECTIVES

The aims of the presented study were the development of four types of silibinin-loaded liposomes (multilamellar liposomes-MLVs, sonicated small unilamellar liposomes-SUVs, UV-irradiated liposomes, and lyophilized liposomes) and their physicochemical characterization and biological potential related to skin health benefits.

METHODS

The characterization was performed via the determination of the encapsulation efficiency (EE), particle size, polydispersity index, zeta potential, conductivity, mobility, storage stability, density, surface tension, viscosity, FT-IR, and Raman spectra. In addition, cytotoxicity on the keratinocytes and antioxidant and anti-inflammatory potential were also determined.

RESULTS

UV irradiation significantly changed the rheological and chemical properties of the liposomes and increased their cytotoxic effect. The lyophilization of the liposomes caused significant changes in their EE and physical characteristics, decreased their ABTS and DPPH radical scavenging potential, and increased their potential to reduce the expression of interleukin 1 beta (IL-1β) in cells treated with bacterial lipopolysaccharide. Sonication significantly changed the EE and physical and rheological properties of the liposomes, and slightly increased their cytotoxicity and reduction effect on IL-1β, while the anti-ABTS and anti-DPPH capacity of the liposomes significantly increased. All developed liposomes showed an increasing trend in particle size and a decreasing trend in zeta potential (absolute values) during storage.

CONCLUSIONS

Silibinin-loaded liposomes (MLVs and lyophilized) showed promising antioxidant activity (toward reactive oxygen species generated in cells) and anti-inflammatory effects (reducing macrophage inhibitory factor expression) on keratinocytes and did not lead to a change in their viability. Future perspectives will focus on wound healing, anti-aging, and other potential of developed liposomes with silibinin in sophisticated cell-based models of skin diseases, wounds, and aging.

Ultraviolet, Did the Cell See It from the Side or the Bottom? Assessment and Modeling of UV Effects on Cultured Cells Using the CL-1000 UV-Crosslinker

Numerous natural extracts and compounds have been evaluated for their ability to mitigate the adverse effects of ultraviolet (UV) overexposure. However, variability in the UV doses that trigger biological responses across studies likely arises from inconsistencies in UV exposure standardization. We hypothesize that these discrepancies are due to variations in culture plates and dishes. The UV dose (D) required to reduce cell viability by 50% differed by a factor of ten between 3.5 cm dishes and 96-well plates. Similarly, the EC50 dose for IL-6 release (D1/2) varied, potentially correlating with the surface area (S). UV exposure to wells with increasing height in 3.5 cm dishes resulted in a decrease in IL-6 release, suggesting that the greater the well height, the more it may influence UV exposure through reflection or shielding effects, thereby contributing to the physiological effects on the cells. To compare these differences among plates, we defined the height-to-diameter ratio (r). Analysis revealed a linear correlation between D1/2 and S in a log-log plot, and between D1/2 and r in a semi-log plot. From this, we defined two empirical indices σ and ρ for UV dose adjustment. A deductive model was also developed to derive a D' value that adjusts UV doses without requiring training. As with σ and ρ, the UV dose D was effectively adjusted using D' as well. These attempts suggest that D' offers a foundational framework for evaluating UVB effects on cultured cells.

The Influence of Circadian Rhythms on DNA Damage Repair in Skin Photoaging

Circadian rhythms, the internal timekeeping systems governing physiological processes, significantly influence skin health, particularly in response to ultraviolet radiation (UVR). Disruptions in circadian rhythms can exacerbate UVR-induced skin damage and increase the risk of skin aging and cancer. This review explores how circadian rhythms affect various aspects of skin physiology and pathology, with a special focus on DNA repair. Circadian regulation ensures optimal DNA repair following UVR-induced damage, reducing mutation accumulation, and enhancing genomic stability. The circadian control over cell proliferation and apoptosis further contributes to skin regeneration and response to UVR. Oxidative stress management is another critical area where circadian rhythms exert influence. Key circadian genes like brain and muscle ARNT-like 1 (BMAL1) and circadian locomotor output cycles kaput (CLOCK) modulate the activity of antioxidant enzymes and signaling pathways to protect cells from oxidative stress. Circadian rhythms also affect inflammatory and immune responses by modulating the inflammatory response and the activity of Langerhans cells and other immune cells in the skin. In summary, circadian rhythms form a complex defense network that manages UVR-induced damage through the precise regulation of DNA damage repair, cell proliferation, apoptosis, inflammatory response, oxidative stress, and hormonal signaling. Understanding these mechanisms provides insights into developing targeted skin protection and improving skin cancer prevention.

Photodynamic activation of phytochemical-antibiotic combinations for combatting Staphylococcus aureus from acute wound infections

Staphylococcus aureus is characterized by its high resistance to conventional antibiotics, particularly methicillin-resistant (MRSA) strains, making it a predominant pathogen in acute and chronic wound infections. The persistence of acute S. aureus wound infections poses a threat by increasing the incidence of their chronicity. This study investigated the potential of photodynamic activation using phytochemical-antibiotic combinations to eliminate S. aureus under conditions representative of acute wound infections, aiming to mitigate the risk of chronicity. The strategy applied takes advantage of the promising antibacterial and photosensitising properties of phytochemicals, and their ability to act as antibiotic adjuvants. The antibacterial activity of selected phytochemicals (berberine, curcumin, farnesol, gallic acid, and quercetin; 6.25-1000 μg/mL) and antibiotics (ciprofloxacin, tetracycline, fusidic acid, oxacillin, gentamicin, mupirocin, methicillin, and tobramycin; 0.0625-1024 μg/mL) was screened individually and in combination against two S. aureus clinical strains (methicillin-resistant and -susceptible-MRSA and MSSA). The photodynamic activity of the phytochemicals was assessed using a light-emitting diode (LED) system with blue (420 nm) or UV-A (365 nm) variants, at 30 mW/cm2 (light doses of 9, 18, 27 J/cm2) and 5.5 mW/cm2 (light doses of 1.5, 3.3 and 5.0 J/cm2), respectively. Notably, all phytochemicals restored antibiotic activity, with 9 and 13 combinations exhibiting potentiating effects on MSSA and MRSA, respectively. Photodynamic activation with blue light (420 nm) resulted in an 8- to 80-fold reduction in the bactericidal concentration of berberine against MSSA and MRSA, while curcumin caused 80-fold reduction for both strains at the light dose of 18 J/cm2. Berberine and curcumin-antibiotic combinations when subjected to photodynamic activation (420 nm light, 10 min, 18 J/cm2) reduced S. aureus culturability by ≈9 log CFU/mL. These combinations lowered the bactericidal concentration of antibiotics, achieving a 2048-fold reduction for gentamicin and 512-fold reduction for tobramycin. Overall, the dual approach involving antimicrobial photodynamic inactivation and selected phytochemical-antibiotic combinations demonstrated a synergistic effect, drastically reducing the culturability of S. aureus and restoring the activity of gentamicin and tobramycin.

Grafting and controlled release of antimicrobial peptides from mesoporous silica

The grafting of antimicrobial peptides onto mesoporous silica particles and their controlled release using a green light-responsive linker, which enables tunable release-concentration-time profiles, is presented. The mesoporous silica surface is functionalized with antimicrobial peptides employing sequential functionalization steps, including the grafting of 3-[(2-propynylcarbamate)propyl]triethoxysilane (PPTEOS) as anchor, boron-dipyrromethene (BODIPY) as photosensitive linker, and C14R peptides as antimicrobial agents. Characterization using scanning electron microscopy (SEM), transmission electron microscopy (TEM), attenuated total reflectance infrared (ATR-IR) spectroscopy, and thermogravimetric analysis (TGA) validate the successful fabrication and functionalization of mesoporous silica. The ester-1,2,3-triazole-BODIPY demonstrates high sensitivity to green light and enables C14R antimicrobial peptide release with adjusted concentration-time profiles. Under the applied conditions up to 64 μg mL-1 were released within 40 minutes. The antimicrobial activity of the released C14R on Escherichia coli. BL21(DE3) is demonstrated. Overall, the use of the photosensitive linker not only provides a promising avenue for controlling the release of biomolecules and therapeutics but also opens up opportunities for the development of materials for targeted release in wound dressings, for example.

NDRG2 Deficiency Exacerbates UVB-Induced Skin Inflammation and Oxidative Stress Damage

UVB radiation induces inflammatory and oxidative stress responses, contributing to skin damage, yet the underlying mechanisms are not fully understood. N-Myc downstream-regulated gene 2 (NDRG2), an emerging stress-associated gene, remains unexplored in UVB-induced skin injury. In this study, we detected skin NDRG2 expression after UVB irradiation for the first time and further used Ndrg2 knockout mice to clarify the role of NDRG2 in UVB-induced skin injury. Three-month-old male Ndrg2+/+ and Ndrg2-/- mice (16-18g) were exposed to UVB to induce acute skin damage, and then dorsal skin samples were collected for subsequent analyses. UVB-induced skin damage was scored. Western Blot Analysis, immunofluorescence (IF) double labeling, and immunohistochemistry (IHC) were employed to assess NDRG2 expression and/or distribution. The concentrations of TNF-α, IL-6, IL-1β, MPO, MMP8, superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) were quantitatively assessed using enzyme-linked immunosorbent assay (ELISA). Hematoxylin and eosin (HE) staining were employed to determine pathological changes. RNA sequencing and analysis were performed to estimate transcript expression levels and analyze mRNA expression. DESeq2 software was employed to identify differentially expressed genes (DEGs). DEGs were visualized using volcanic and heat maps. Gene Ontology (GO) functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed to identify primary biological functions, metabolic pathways, or signal transduction pathways associated with DEGs. UVB-challenged Ndrg2-/- mice exhibited significantly exacerbated skin damage (erythema, edema, and erosion), neutrophil infiltration, and apoptosis compared to Ndrg2+/+ mice. Furthermore, UVB-challenged Ndrg2-/- mice displayed significantly elevated pro-inflammatory cytokines, myeloperoxidase (MPO), matrix metalloproteinase-8 (MMP8), and reduced antioxidant expression. RNA sequencing identified 1091 significantly differentially expressed genes enriched in inflammation, immune response, and oxidative stress pathways. In conclusion, the deficiency of Ndrg2 markedly exacerbated UVB-induced skin damage by promoting inflammatory responses and inhibiting antioxidant responses. This suggests that stabilizing NDRG2 expression holds promise as a therapeutic strategy for protecting against UVB-induced skin damage.

Blue light irradiation suppresses oral squamous cell carcinoma through induction of endoplasmic reticulum stress and mitochondrial dysfunction

The therapeutic potential of blue light photobiomodulation in cancer treatment, particularly in inhibiting cell proliferation and promoting cell death, has attracted significant interest. Oral squamous cell carcinoma (OSCC) is a prevalent form of oral cancer, necessitating innovative treatment approaches to improve patient outcomes. In this study, we investigated the effects of 420 nm blue LED light on OSCC and explored the underlying mechanisms. Our results demonstrated that 420 nm blue light effectively reduced OSCC cell viability and migration, and induced G2/M arrest. Moreover, we observed that 420 nm blue light triggered endoplasmic reticulum (ER) stress and mitochondrial dysfunction in OSCC cells, leading to activation of the CHOP signal pathway and alterations in the levels of Bcl-2 and Bax proteins, ultimately promoting cell apoptosis. Additionally, blue light suppressed mitochondrial gene expression, likely due to its damage to mitochondrial DNA. This study highlights the distinct impact of 420 nm blue light on OSCC cells, providing valuable insights into its potential application as a clinical treatment for oral cancer.

Gut-derived wild blueberry phenolic acid metabolites modulate extrinsic cutaneous damage

As the first line of defense, the skin is equipped with various physiological mechanisms positioned to prevent incoming oxidative damage from numerous environmental insults. With persistent exposure to the environment, understanding ways to augment the skin defenses is paramount in protecting from premature aging. In this study, we investigated the ability of five dietary phenolic metabolites, typically found in the bloodstream after wild blueberry consumption, to successfully defend the skin from UV light exposure in a novel ex vivo co-culture model of human skin explants and primary endothelial cells. Skin explants, placed in transwell inserts, were exposed to UV, and subsequently co-cultured with endothelial cells. When the endothelial cells had been pretreated with the bioactive metabolites at physiological concentrations (hippuric acid 3000 nM, isoferulic acid 1000 nM, salicylic acid 130 nM, benzoic acid 900 nM, α-hydroxyhippuric acid 400 nM) cutaneous damage was prevented on the co-cultured with UV-challenged skin explants. Co-culture with non-pretreated endothelial cells did not protect skin explants. Specifically, the pretreatment was able to reduce skin lipid peroxidation (measured as 4-hydroxynonenal protein adducts), and pro-inflammatory enzymes such as cyclooxygenase 2 (COX-2) and NADPH oxidase 4 (NOX-4). Furthermore, pretreatment with the metabolites prevented UV-induced release of inflammatory cytokines such as IL-1β and IL-8 as well as nitric oxides (NO) levels. In addition, the metabolites showed an impressive ability to prevent the loss of cutaneous structural proteins including involucrin and collagen type 1. Of note, endothelial cells cultured with UV exposed skin explants exhibited increased oxidative stress demonstrated by heme oxygenase-1 (HO-1) up-regulation which was significantly prevented in the metabolite treated models. These findings highlight the ability of dietary polyphenolic metabolites to improve cutaneous defenses against extrinsic stressors.

A Clean and Health-Care-Focused Way to Reduce Indoor Airborne Bacteria in Calf House with Long-Wave Ultraviolet

Long-term exposure to a relatively high concentration of airborne bacteria emitted from intensive livestock houses could potentially threaten the health and welfare of animals and workers. There is a dual effect of air sterilization and promotion of vitamin D synthesis for the specific bands of ultraviolet light. This study investigated the potential use of A-band ultraviolet (UVA) tubes as a clean and safe way of reducing airborne bacteria and improving calf health. The composition and emission characteristics of airborne bacteria were investigated and used to determine the correct operating regime of UVA tubes in calf houses. Intermittent exceedances of indoor airborne bacteria were observed in closed calf houses. The measured emission intensity of airborne bacteria was 1.13 ± 0.09 × 107 CFU h-1 per calf. Proteobacteria were the dominant microbial species in the air inside and outside calf houses. After UVA radiation, the indoor culturable airborne bacteria decreased in all particle size ranges of the Anderson sampler, and it showed the highest reduction rate in the size range of 3.3-4.7 μm. The results of this study would enrich the knowledge of the source characteristics of the airborne bacteria in intensive livestock farming and contribute to the environmental control of cattle in intensive livestock production.

A review of the botany, phytochemistry, pharmacology, synthetic biology and comprehensive utilization of Silybum marianum

Silybum marianum (L.) Gaertn, a herbaceous plant with a long history in traditional medicine for the treatment of hepatobiliary diseases, particularly in Europe, which has attracted attention for its remarkable therapeutic effect. This review systematically summarizes the research progress in the botany, phytochemistry, pharmacology, comprehensive utilization and synthetic biology of S. marianum. Up to now, more than 20 types of flavonolignan components have been isolated from S. marianum. In addition, the rearch on fatty acids and triterpenoids is also constantly improving. Among them, silybin is the most active compound in flavonolignans components. Its pharmacological effects in vivo and in vitro include anti-inflammatory, antioxidant, anti-tumour, hypoglycaemic, neuroprotective and immunoregulatory properties. The use of coniferyl alcohol and taxifolin as substrates to produce silybin and isosilybin under the action of enzyme catalysis is the commonly used biosynthetic pathway of silymarin, which provides support for a comprehensive analysis of the synthetic pathway of silymarin. In addition to medicinal use, the extracts of plants also have broad application prospects in the production of food, healthcare products, cosmetics and other aspects. In addition, the chemical composition, pharmacological mechanism and synthetic biology of S. marianum need to be further studied, which is very important for its clinical efficacy and resource development.

Naturally Derived Luminescent Material in Engineered Silk and Its Application as a Fluorescent Dye with a Large Stokes Shift and Sensing Capability

Silkworms have provided valuable byproducts (spanning from high-quality textiles to health supplements) to humans for millennia. Despite their importance in sericultural economy and biotechnology, manifold possibilities inherent in the myriad natural or artificially generated silk varieties have been underestimated. In this paper, we report that the Yeonnokjam silk strain, which shows light-green color, contains quercetin fluorochrome (QueF) in sericin, and QueF can be used as a fluorescence dye with a large Stokes shift and high sensitivity to environmental temperature and pH, thus functioning as an environmental sensing material. A Stokes shift exceeding 180 nm, a quantum efficiency of 1.28%, and a rapid fluorescence decay of 0.67 ns are obtained, which are influenced by solvent polarities. Moreover, QueF can be used as a UV blocker as well, and its low cytotoxicity and biocompatibility further suggest promising prospects for diverse application in cosmetics and medical materials in the future.

Therapeutic effect of NEO400, perillyl alcohol conjugated to linoleic acid, in a mouse model of UV-induced skin damage

Excessive exposure to ultraviolet radiation (UVR) causes harmful effects on human skin. Pre-exposure application of sunscreen can be protective, but not after damage already has occurred. There is a need for agents that can be applied post-UVR exposure to repair the damage. We investigated a novel compound, NEO400, that appears to meet this medicinal need. NEO400 was created by conjugating linoleic acid to perillyl alcohol. UVR was repeatedly administered to the skin of mice over several weeks, where it caused the typical signs of UV damage, including scaling of the skin, DNA damage, and elevated levels of inflammatory cytokines. However, when NEO400 was applied immediately post-UVR, it triggered the appearance of markers for dermal stem cell proliferation, and no signs of skin damage emerged. Furthermore, when NEO400 was applied to skin that already had incurred significant damage, it accelerated skin healing. When applied individually, linoleic acid and perillyl alcohol were ineffective, indicating that they had to be conjugated in order to exert therapeutic efficacy. None of these skin-protective effects could be achieved with Aloe vera gel, a popular and widely used post-exposure remedy. Our study suggests that NEO400 holds potential as a regenerative treatment for excessively UVR-exposed skin.

PTGES2 and RNASET2 identified as novel potential biomarkers and therapeutic targets for basal cell carcinoma: insights from proteome-wide mendelian randomization, colocalization, and MR-PheWAS analyses

Introduction

Basal cell carcinoma (BCC) is the most common skin cancer, lacking reliable biomarkers or therapeutic targets for effective treatment. Genome-wide association studies (GWAS) can aid in identifying drug targets, repurposing existing drugs, predicting clinical trial side effects, and reclassifying patients in clinical utility. Hence, the present study investigates the association between plasma proteins and skin cancer to identify effective biomarkers and therapeutic targets for BCC.

Methods

Proteome-wide mendelian randomization was performed using inverse-variance-weight and Wald Ratio methods, leveraging 1 Mb cis protein quantitative trait loci (cis-pQTLs) in the UK Biobank Pharma Proteomics Project (UKB-PPP) and the deCODE Health Study, to determine the causal relationship between plasma proteins and skin cancer and its subtypes in the FinnGen R10 study and the SAIGE database of Lee lab. Significant association with skin cancer and its subtypes was defined as a false discovery rate (FDR) < 0.05. pQTL to GWAS colocalization analysis was executed using a Bayesian model to evaluate five exclusive hypotheses. Strong colocalization evidence was defined as a posterior probability for shared causal variants (PP.H4) of ≥0.85. Mendelian randomization-Phenome-wide association studies (MR-PheWAS) were used to evaluate potential biomarkers and therapeutic targets for skin cancer and its subtypes within a phenome-wide human disease category.

Results

PTGES2, RNASET2, SF3B4, STX8, ENO2, and HS3ST3B1 (besides RNASET2, five other plasma proteins were previously unknown in expression quantitative trait loci (eQTL) and methylation quantitative trait loci (mQTL)) were significantly associated with BCC after FDR correction in the UKB-PPP and deCODE studies. Reverse MR showed no association between BCC and these proteins. PTGES2 and RNASET2 exhibited strong evidence of colocalization with BCC based on a posterior probability PP.H4 >0.92. Furthermore, MR-PheWAS analysis showed that BCC was the most significant phenotype associated with PTGES2 and RNASET2 among 2,408 phenotypes in the FinnGen R10 study. Therefore, PTGES2 and RNASET2 are highlighted as effective biomarkers and therapeutic targets for BCC within the phenome-wide human disease category.

Conclusion

The study identifies PTGES2 and RNASET2 plasma proteins as novel, reliable biomarkers and therapeutic targets for BCC, suggesting more effective clinical application strategies for patients.

UV radiation-induced peptides in frog skin confer protection against cutaneous photodamage through suppressing MAPK signaling

Overexposure to ultraviolet light (UV) has become a major dermatological problem since the intensity of ultraviolet radiation is increasing. As an adaption to outside environments, amphibians gained an excellent peptide-based defense system in their naked skin from secular evolution. Here, we first determined the adaptation and resistance of the dark-spotted frogs (Pelophylax nigromaculatus) to constant ultraviolet B (UVB) exposure. Subsequently, peptidomics of frog skin identified a series of novel peptides in response to UVB. These UV-induced frog skin peptides (UIFSPs) conferred significant protection against UVB-induced death and senescence in skin cells. Moreover, the protective effects of UIFSPs were boosted by coupling with the transcription trans-activating (TAT) protein transduction domain. In vivo, TAT-conjugated UIFSPs mitigated skin photodamage and accelerated wound healing. Transcriptomic profiling revealed that multiple pathways were modulated by TAT-conjugated UIFSPs, including small GTPase/Ras signaling and MAPK signaling. Importantly, pharmacological activation of MAPK kinases counteracted UIFSP-induced decrease in cell death after UVB exposure. Taken together, our findings provide evidence for the potential preventive and therapeutic significance of UIFSPs in UV-induced skin damage by antagonizing MAPK signaling pathways. In addition, these results suggest a practicable alternative in which potential therapeutic agents can be mined from organisms with a fascinating ability to adapt.

Baicalin attenuates acute skin damage induced by ultraviolet B via inhibiting pyroptosis

As the outermost layer of the human body, the skin suffers from various external factors especially light damage, among which ultraviolet B (UVB) irradiation is common and possesses a relatively high biological damage capacity. Pyroptosis is a newly discovered type of programmed cell death, which can induce cell rupture and induce local inflammatory response. However, the molecular mechanisms of pyroptosis in photodamaged skin is poorly understood. Baicalin, a flavonoid extracted from the desiccated root of Scutellaria baicalensis Georgi (Huang Qin). Despite its antioxidant abilities, whether baicalin protects skin by attenuating UVB-induced pyroptosis remains unclear, which was the aim of this study. The UVB-induced acute skin damage model was established by using human immortalized keratinocytes (HaCaT cells) and Kunming (KM) strain mice. The protective dose selection for baicalin is 50 μM in vitro and 100 mg/kg in vivo. In in vitro study, UVB irradiation significantly decreased cell viability, increased cell death and oxidative stress in HaCaT cells, while pretreatment with baicalin improved these phenomena. Furthermore, the baicalin pretreatment notably suppressed nuclear factor kappa B (NF-κB) translocation, the NLRP3 inflammasome activation and gasdermin D (GSDMD) maturation, thus effectively attenuating UVB-induced pyroptosis. In in vivo study, the baicalin pretreatment mitigated epidermal hyperplasia, collagen fiber fragmentation, oxidative stress and pyroptosis in UVB-irradiated mouse skin. In a nutshell, this study suggests that baicalin could be a potential protective agent to attenuate acute skin damage induced by UVB irradiation through decreasing oxidative stress and suppressing NF-κB/NLRP3/GSDMD-involved pyroptosis.

The Caspase-Activated DNase drives inflammation and contributes to defense against viral infection

Mitochondria react to infection with sub-lethal signals in the apoptosis pathway. Mitochondrial signals can be inflammatory but mechanisms are only partially understood. We show that activation of the caspase-activated DNase (CAD) mediates mitochondrial pro-inflammatory functions and substantially contributes to host defense against viral infection. In cells lacking CAD, the pro-inflammatory activity of sub-lethal signals was reduced. Experimental activation of CAD caused transient DNA-damage and a pronounced DNA damage response, involving major kinase signaling pathways, NF-κB and cGAS/STING, driving the production of interferon, cytokines/chemokines and attracting neutrophils. The transcriptional response to CAD-activation was reminiscent of the reaction to microbial infection. CAD-deficient cells had a diminished response to viral infection. Influenza virus infected CAD-deficient mice displayed reduced inflammation in lung tissue, higher viral titers and increased weight loss. Thus, CAD links the mitochondrial apoptosis system and cell death caspases to host defense. CAD-driven DNA damage is a physiological element of the inflammatory response to infection.

Impact of double-strand breaks induced by uv radiation on neuroinflammation and neurodegenerative disorders

Exposure to UV affects the development and growth of a wide range of organisms. Nowadays, researchers are focusing on the impact of UV radiation and its underlying molecular mechanisms, as well as devising strategies to mitigate its harmful effects. Different forms of UV radiation, their typical exposure effects, the impact of UV on DNA integrity, and the deterioration of genetic material are discussed in this review; furthermore, we also review the effects of UV radiation that affect the biological functions of the organisms. Subsequently, we address the processes that aid organisms in navigating the damage in genetic material, neuroinflammation, and neurodegeneration brought on by UV-mediated double-strand breaks. To emphasize the molecular pathways, we conclude the review by going over the animal model studies that highlight the genes and proteins that are impacted by UV radiation.

Enhanced sun protection factor of octocrylene with green tea and bhringraj extracts

OBJECTIVES

The aim of this study of sun protection factor boosting effect sunscreen compositions with herbal extract and combination with octocrylene.

MATERIALS AND METHODS

The standardized herbal extracts procured and studied their sun protection Factors. Camellia Sinensis (Green tea) leaf Extract, Eclipta prostrata (bhringraj) leaf extract are selected for the development of the herbal sunscreen composition along with octocrylene as synthetic sunscreen. The developed sunscreen composition contains defined concentration of herbal extracts and octocrylene were evaluated for their different physicochemical properties and stability. Sun protection factor boosting effect of herbal extracts is studied combination with octocrylene.

RESULTS

Invitro SPF studied for herbal extract individually and combination with octocrylene. The results of Invitro SPF study revealed the presence of green tea extract and, Eclipta prostrata (bhringraj) leaf extract shows excellent sun protection factor (SPF) boosting value of sunscreen composition containing 5% concentration of herbal extract and octocrylene. The sunscreen formulation containing 5% herbal extracts are stable for 12 weeks in an oven (45 °C).

CONCLUSION

The findings of this in-vitro SPF study revealed a sun protection boosting capacity of green tea extract and bhringraj extract confirmed.

SUMMARY

The over exposure of human skin to Ultra-Violet Radiation (UVR) can trigger photodamage, UV burn, pigmentation, erythema, and enhance the chance of dermal carcinoma. UVR causes DNA damage, which leads to dermal cancer. Daily sunscreens protect the skin from the adverse effects of sun rays, especially UVB (290-320 nm) and UVA (320-400 nm). The ozone layer filters UVC (200-290 nm) radiation when it enters into atmosphere of the earth. UVB causes sunburn, photo damage and cause mutagenic changes in nucleic acids. UVA increases ROS (Reactive Oxygen Species) accumulation. ROS is responsible for cell repair which leads to carcinogenesis, and the cause of photodamage. Herbal extracts contain polyphenols, and flavonoids act as a natural sunscreen that will filter Ultra-Violet (UVB) light and contain antioxidant characteristics to modulate the photo-oxidative damage that results from UV-induced Reactive Oxygen Species production. The UVR protection of most herbal extracts are required to attain the higher UV protection in the sun care products. The approaches for preparing sun care products with higher Sun Protection Factor (SPF) possible through Oil in water formulation with herbal extract combinations of octocrylene. The developed sunscreen composition containing different concentration of herbal extracts were evaluated for their other physicochemical properties and stability. Invitro SPF was studied for Camellia Sinensis (Green tea) Leaf Extract and Eclipta prostrata (bhringraj) leaf extract individually and in combination with octocrylene. The results of the Invitro SPF study revealed the Camellia Sinensis (Green tea) Leaf Extract with octocrylene shows better Sun protection factor than Eclipta prostrata (bhringraj) leaf extract with octocrylene. The Sun Protection Factor (SPF) enhancement value of sunscreen compositions was compared to both sunscreen macroemulsion and nanoemulsion.

Indian Gooseberry and Barley Sprout Complex Prevent Oxidative Stress and Photoaging of the Skin in Ultraviolet B-Irradiated SHK-I Mice

This study investigated the protective effects of a complex of Indian gooseberry and barley sprout (IB complex) on oxidative stress and skin damage caused by ultraviolet B irradiation in SHK-I hairless mice. The study examined the impact of IB complex on skin hydration, wrinkle formation, and melanogenesis using enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and western blot analysis. The IB complex reduced skin hydration loss and wrinkle formation, while also demonstrating enhanced antioxidant activities. The IB complex maintained skin hydration via upregulation of hyaluronic acid and ceramide synthesis, including the regulation of hyaluronic acid synthase, long-chain ceramide formation, dihydroceramide desaturase 1 activity, and type I collagen production. The IB complex prevented wrinkle formation via downregulating JNK and upregulating TGF-β pathways. Moreover, IB complex blocked melanin production via inhibition of protein kinase A, cAMP response element-binding protein, and microphthalmia-associated transcription factor pathways. These results suggest that IB complex is a potential agent to protect the skin against photodamage caused by exposure to UVB radiation. The research protocols underwent approval from the Institutional Animal Care and Use Committee of Kyung Hee University (KHGASP-21-577), ensuring compliance with ethical standards.

Exposure to UV-B filter octylmethoxycinnamate and human health effects: Focus on endocrine disruptor actions

Human skin is the first line of photoprotection against UV radiation. However, despite having its defence mechanisms, the photoprotection that the skin exerts is not enough. To protect human skin, the inclusion of UV filters in the cosmetic industry has grown significantly as a photoprotection strategy. Octylmethoxycinnamate, also designated by octinoxate, or 2-ethylhexyl-4-methoxycinnamate (CAS number: 5466-77-3) is one of the most widely used UV-B filter in the cosmetic industry. The toxic effects of OMC have alarmed the public, but there is still no consensus in the scientific community about its use. This article aims to provide an overview of the UV filters' photoprotection, emphasizing the OMC and the possible negative effects it may have on the public health. Moreover, the current legislation will be addressed. In summary, the recommendations should be rethought to assess their risk-benefit, since the existing literature warns us to endocrine-disrupting effects of OMC. Further studies should be focus on the toxicity of OMC alone, in mixture and should consider its degradation products, to improve the knowledge of its risk assessment as EDC.

Ex Vivo Analysis of Cell Differentiation, Oxidative Stress, Inflammation, and DNA Damage on Cutaneous Field Cancerization

Cutaneous field cancerization (CFC) refers to a skin region containing mutated cells' clones, predominantly arising from chronic exposure to ultraviolet radiation (UVR), which exhibits an elevated risk of developing precancerous and neoplastic lesions. Despite extensive research, many molecular aspects of CFC still need to be better understood. In this study, we conducted ex vivo assessment of cell differentiation, oxidative stress, inflammation, and DNA damage in CFC samples. We collected perilesional skin from 41 patients with skin cancer and non-photoexposed skin from 25 healthy control individuals. These biopsies were either paraffin-embedded for indirect immunofluorescence and immunohistochemistry stain or processed for proteins and mRNA extraction from the epidermidis. Our findings indicate a downregulation of p53 expression and an upregulation of Ki67 and p16 in CFC tissues. Additionally, there were alterations in keratinocyte differentiation markers, disrupted cell differentiation, increased expression of iNOS and proinflammatory cytokines IL-6 and IL-8, along with evidence of oxidative DNA damage. Collectively, our results suggest that despite its outwardly normal appearance, CFC tissue shows early signs of DNA damage, an active inflammatory state, oxidative stress, abnormal cell proliferation and differentiation.

Quantum Sensing of Free Radical Generation in Mitochondria of Human Keratinocytes during UVB Exposure

Ultraviolet (UV) radiation is known to cause skin issues, such as dryness, aging, and even cancer. Among UV rays, UVB stands out for its ability to trigger problems within cells, including mitochondrial dysfunction, oxidative stress, and DNA damage. Free radicals are implicated in these cellular responses, but they are challenging to measure due to their short lifetime and limited diffusion range. In our study, we used a quantum sensing technique (T1 relaxometry) involving fluorescent nanodiamonds (FNDs) that change their optical properties in response to magnetic noise. This allowed us to monitor the free radical presence in real time. To measure radicals near mitochondria, we coated FNDs with antibodies, targeting mitochondrial protein voltage-dependent anion channel 2 (anti-VDAC2). Our findings revealed a dynamic rise in radical levels on the mitochondrial membrane as cells were exposed to UVB (3 J/cm2), with a significant increase observed after 17 min.

Protective effect of Helianthus annuus seed byproduct extract on ultraviolet radiation-induced injury in skin cells

Helianthus annuus seed byproduct is a residual product obtained after seed oil extraction. The present study investigated the preventive and repair effects of the H. annuus seed byproduct ethanol extract (HSE) on ultraviolet radiation (UVR)-induced injury in human immortalized keratinocytes (HaCaTs) and human skin fibroblasts (HSFs). Results revealed that the total phenolic acid and oligosaccharide content in HSE was >50%. HSE had a stronger preventive effect on UVR-induced injury than the repair effect. Moreover, phenolic acids were the main active component of HSE mediating the preventative effect. In HaCaTs and HSFs, HSE prevented UVR-induced injury by inhibiting excessive ROS production. It reduced the secretion of tumor necrosis TNF-α, IL-1α, IL-1β, IL-6, and IL-8 by inhibiting the level of ROS, thus reducing inflammation-mediated injury to skin cells. In addition, HSE inhibited the expression of various mRNA kinases in the MAPK-ERK/p38/JNK pathway. This downregulated the expression of activator protein-1 (AP-1) mRNA and further reduced the secretion of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-9 as well as reduced UVR-induced injury to the cells. In conclusion, HSE is a broad-spectrum, natural UV filter with high efficiency and low toxicity that has the potential to be used in sunscreen products.

Melanin Biopolymers in Pharmacology and Medicine-Skin Pigmentation Disorders, Implications for Drug Action, Adverse Effects and Therapy

Melanins are biopolymeric pigments formed by a multi-step oxidation process of tyrosine in highly specialized cells called melanocytes. Melanin pigments are mainly found in the skin, iris, hair follicles, and inner ear. The photoprotective properties of melanin biopolymers have been linked to their perinuclear localization to protect DNA, but their ability to scavenge metal ions and antioxidant properties has also been noted. Interactions between drugs and melanins are of clinical relevance. The formation of drug-melanin complexes can affect both the efficacy of pharmacotherapy and the occurrence of adverse effects such as phototoxic reactions and discoloration. Because the amount and type of melanin synthesized in the body is subject to multifactorial regulation-determined by both internal factors such as genetic predisposition, inflammation, and hormonal balance and external factors such as contact with allergens or exposure to UV radiation-different effects on the melanogenesis process can be observed. These factors can directly influence skin pigmentation disorders, resulting in hypopigmentation or hyperpigmentation of a genetic or acquired nature. In this review, we will present information on melanocyte biology, melanogenesis, and the multifactorial influence of melanin on pharmacological parameters during pharmacotherapy. In addition, the types of skin color disorders, with special emphasis on the process of their development, symptoms, and methods of treatment, are presented in this article.

Efficacy of Combinational Treatment versus Nicotinamide Monotherapy in the Prevention of Ultraviolet Radiation-Induced Skin Cancer

INTRODUCTION

Ultraviolet radiation (UVR) is the primary risk factor for keratinocyte carcinomas. Oral supplementation with nicotinamide (NAM) is reported to reduce the formation of new keratinocyte carcinomas. NAM's photoprotection is mediated by enhanced DNA repair. We wanted to explore whether NAM in combination with antiproliferative (metformin [Met]) or antioxidant (phloroglucinol [PG]) compounds could potentially enhance its photoprotective effects.

METHODS

Hairless mice (C3.Cg-Hrhr/TifBomTac) were treated orally with either a standard dose of NAM monotherapy (NAM-mono; 600 mg/kg) or NAM (400 mg/kg) combined with Met (200 mg/kg) (NAM-Met) or PG (75 mg/kg) (NAM-PG). Mice were irradiated with 3.5 standard erythema doses of UVR three times per week to induce tumour development. Photoprotective effects were based on (i) tumour onset of the first three tumours, (ii) skin photodamage, and (iii) DNA damage (cyclobutane pyrimidine dimers [CPDs] and pyrimidine-pyrimidone (6-4) photoproducts [6-4PPs]).

RESULTS

All mice treated with NAM demonstrated a delay in tumour onset and reduced tumour burden compared to the UV control group (NAM, NAM-Met, NAM-PG vs. UV control: p ≤ 0.015). NAM-mono and NAM-PG increased time until all three tumours with no difference between them, indicating a similar degree of photoprotection. NAM-mono had no effect on DNA damage compared to the UV control group (p > 0.05), whereas NAM-PG reduced 6-4PP lesions (p < 0.01) but not CPDs (p > 0.05) compared to NAM-mono. NAM-Met delayed the onset of the third tumour compared to the UV control but demonstrated a quicker onset compared to NAM-mono, suggesting inferior photoprotection compared to nicotinamide monotherapy.

CONCLUSION

NAM-PG was as effective in delaying UVR-induced tumour onset as NAM-mono. The reduction in 6-4PP lesions may indicate that the mechanism of NAM-PG is better suited for photoprotection than NAM-mono. NAM-mono was superior to NAM-Met, indicating a dose dependency of NAM's photoprotection. These results highlight the potential for combining photoprotective compounds to enhance photoprotection.

Design of Bombyx mori (B. mori) Silk Fibroin Microspheres for Developing Biosafe Sunscreen

Sunscreens play a crucial role in protecting the skin from ultraviolet (UV) damage. However, present commercial sunscreens have a tendency to generate free radicals in the UV window, resulting in serious inflammatory responses and health problems. In this study, we demonstrate that silk fibroin microspheres (SFMPs) assembled from regenerated silk fibroin (SF) could scavenge free radicals while preventing UV irradiation and thus present a promising sunscreen. The SFMP reflected more UV light than SF and presented a higher stability than that of organic commercial sunscreens. In vitro analysis proved that SFMP could more efficiently scavenge the hydroxy radical and reduce the intracellular reactive oxygen than titanium dioxide (TiO2). In vivo experiments exhibited that SFMP provided stronger skin protection against UV irradiation than commercial sunscreens and TiO2. Furthermore, SFMP treatment significantly inhibited the skin inflammatory response. This work suggests that the SFMP has great potential to be developed into a biosafe sunscreen.

Light-Activated Synthetic Rotary Motors in Lipid Membranes Induce Shape Changes Through Membrane Expansion

Membranes are the key structures to separate and spatially organize cellular systems. Their rich dynamics and transformations during the cell cycle are orchestrated by specific membrane-targeted molecular machineries, many of which operate through energy dissipation. Likewise, man-made light-activated molecular rotary motors have previously shown drastic effects on cellular systems, but their physical roles on and within lipid membranes remain largely unexplored. Here, the impact of rotary motors on well-defined biological membranes is systematically investigated. Notably, dramatic mechanical transformations are observed in these systems upon motor irradiation, indicative of motor-induced membrane expansion. The influence of several factors on this phenomenon is systematically explored, such as motor concentration and membrane composition., Membrane fluidity is found to play a crucial role in motor-induced deformations, while only minor contributions from local heating and singlet oxygen generation are observed. Most remarkably, the membrane area expansion under the influence of the motors continues as long as irradiation is maintained, and the system stays out-of-equilibrium. Overall, this research contributes to a comprehensive understanding of molecular motors interacting with biological membranes, elucidating the multifaceted factors that govern membrane responses and shape transitions in the presence of these remarkable molecular machines, thereby supporting their future applications in chemical biology.

Polyphenolic Platform Ameliorated Sanshool for Skin Photoprotection

Natural evolution has nurtured a series of active molecules that play vital roles in physiological systems, but their further applications have been severely limited by rapid deactivation, short cycle time, and potential toxicity after isolation. For instance, the instability of structures and properties has greatly descended when sanshool is derived from Zanthoxylum xanthoxylum. Herein, natural polyphenols are employed to boost the key properties of sanshool by fabricating a series of nanoparticles (NPs). The intracellular evaluation and in vivo animal model are conducted to demonstrate the decreased photodamage score and skin-fold thickness of prepared NPs, which can be attributed to the better biocompatibility, improved free radical scavenging, down-regulated apoptosis ratios, and reduced DNA double-strand breaks compared to naked sanshool. This work proposes a novel strategy to boost the key properties of naturally occurring active molecules with the assistance of natural polyphenol-based platforms.

[Difficult-to-treat chronic rhinosinusitis-when the standard treatment is not effective and biologics are not available]

BACKGROUND

In recent years, significant improvements have been made in the treatment options for uncontrolled chronic rhinosinusitis (CRS) refractory to standard medical and surgical therapy. This is the result of a better understanding of the pathophysiology and the resulting development of biologicals for CRS with nasal polyps (CRSwNP). However, biologics are not (yet) available for all patients in Europe.

OBJECTIVE

Based on the session "Difficult-to-treat CRS, when biologics are not available" at the 29th Congress of the European Rhinologic Society (ERS) 2023 in Sofia, Bulgaria, the treatment options for uncontrolled CRS with the exclusion of biologics will be discussed.

MATERIALS AND METHODS

The content of the presentations "Is there a place for antibiotics?" "Indications for revision surgery," "Novel systemic treatment options," "Novel local treatment options," and "Phototherapy for nasal polyps" are outlined and supported by a review of the literature.

RESULTS

Various treatment options are available for managing uncontrolled CRS, even if biologic treatments are unavailable. Treatment options for type‑2 (T2) CRS include steroid rinses, repeated short-term oral steroids, steroid-eluting stents, and extended sinus surgery. In the case of nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD), acetylsalicylic acid (ASA) desensitization can be considered. Non-T2 endotypes or CRS without nasal polyps (CRSsNP) may benefit from several weeks of macrolides and xylitol rinses.

CONCLUSION

To accurately assess the efficacy of second-line therapies for treatment of difficult-to-treat CRS within an endotype-specific framework, additional controlled clinical trials are needed that take into account the heterogeneity of CRS endotypes.

Nrf2 activation: a key mechanism in stem cell exosomes-mediated therapies

Exosomes are nano-sized membrane extracellular vesicles which can be released from various types of cells. Exosomes originating from inflammatory or injured cells can have detrimental effects on recipient cells, while exosomes derived from stem cells not only facilitate the repair and regeneration of damaged tissues but also inhibit inflammation and provide protective effects against various diseases, suggesting they may serve as an alternative strategy of stem cells transplantation. Exosomes have a fundamental role in communication between cells, through the transfer of proteins, bioactive lipids and nucleic acids (like miRNAs and mRNAs) between cells. This transfer significantly impacts both the physiological and pathological functions of recipient cells. Nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor, is able to mitigate damage caused by oxidative stress and inflammation through various signaling pathways. The positive effects resulting from the activation of the Nrf2 signaling pathway in different disorders have been documented in various types of literature. Studies have confirmed that exosomes derived from stem cells could act as Nrf2 effective agonists. However, limited studies have explored the Nrf2 role in the therapeutic effects of stem cell-derived exosomes. This review provides a comprehensive overview of the existing knowledge concerning the role of Nrf2 signaling pathways in the impact exerted by stem cell exosomes in some common diseases.

Integrative analysis of RNA-sequencing and microarray for the identification of adverse effects of UVB exposure on human skin

Background

Ultraviolet B (UVB) from sunlight represents a major environmental factor that causes toxic effects resulting in structural and functional cutaneous abnormalities in most living organisms. Although numerous studies have indicated the biological mechanisms linking UVB exposure and cutaneous manifestations, they have typically originated from a single study performed under limited conditions.

Methods

We accessed all publicly accessible expression data of various skin cell types exposed to UVB, including skin biopsies, keratinocytes, and fibroblasts. We performed biological network analysis to identify the molecular mechanisms and identify genetic biomarkers.

Results

We interpreted the inflammatory response and carcinogenesis as major UVB-induced signaling alternations and identified three candidate biomarkers (IL1B, CCL2, and LIF). Moreover, we confirmed that these three biomarkers contribute to the survival probability of patients with cutaneous melanoma, the most aggressive and lethal form of skin cancer.

Conclusion

Our findings will aid the understanding of UVB-induced cutaneous toxicity and the accompanying molecular mechanisms. In addition, the three candidate biomarkers that change molecular signals due to UVB exposure of skin might be related to the survival rate of patients with cutaneous melanoma.

UV index-based model for predicting synthesis of (pre-)vitamin D3 in the mediterranean basin

The importance of solar radiation for the body's ability to synthesize Vitamin D3 is well documented, yet the precise amount of sun exposure required to avoid Vitamin D insufficiency is less clear. To address this knowledge gap, this study sought to utilize the sun in a suitable period at the optimum dose by utilizing numerical simulations to determine the amount of Vitamin D3 synthesis in the skin according to season, time of day, and geographical location in Turkey. The study was carried out in three stages; in the first stage, daily, monthly, and annual values were determined in cases where the solar zenith angle has the active UV-B wavelength. The second stage determined the level of Vitamin D that can be synthesized in all skin types at 25% solar radiation exposure. In the third stage, the sun exposure time required for 1000 International Units (IU) for all skin types was calculated. According to the analysis, the yearly period of active synthesis of D3 on Earth lasts from the beginning of March to the third week of October. During the day, it is between 10:00 and 16:00. For 1000 IU/day, the average annual estimated times (minutes) are 5.05 for Type I, 6.3 for Type II, 7.6 for Type III, 11.35 for Type IV, 15.15 for Type V, and 25.25 for Type VI. The results of this paper will impact awareness for academic-medical users.

Livin is protective in UVB-induced skin photodamage by regulating keratinocyte activation and inflammatory responses

UVB radiation can lead to skin photodamage, which might arise from keratinocyte (KC) activation. Nuclear factor kappa B (NF-κB) assumes an essential function in the context of UVB-triggered skin photodamage. Initiating the NF-κB cascade leads to the release of inflammatory factors from KCs. Livin can modulate both KC activation and function, yet it remains uncertain whether and how Livin regulates KC activation induced by UVB. To explore the involvement of Livin in UVB-triggered skin photodamage and its impact on skin damage through NF-κB activation. Immunofluorescence staining was used to analyse the expression of Livin in individuals with skin photodamage and in mice treated with UVB radiation. KC-specific Livin knockout (LivinΔKC ) mice and HaCaT cells with Livin knockdown were employed to examine the function of Livin in regulating KC activation induced by UVB radiation. Additionally, the impact of Livin on the NF-κB cascade during KC activation was confirmed via western blot analysis. In patients with skin photodamage, UVB-treated mice and HaCaT cells, Livin expression was reduced in KCs. LivinΔKC mice displayed heightened sensitivity to UVB radiation, resulting in more pronounced skin damage and inflammatory responses compared to the control Livinfl/fl mice. Following UVB exposure, both LivinΔKC mice and Livin-knockdown HaCaT cells released elevated levels of cytokines compared to their respective controls. Moreover, the UVB-induced activation of NF-κB in HaCaT cells was significantly enhanced following Livin knockdown. Our findings propose that Livin within KCs could contribute to reducing UVB-induced skin photodamage by regulating the NF-κB pathway.

Causal relationship between the gut microbiome and basal cell carcinoma, melanoma skin cancer, ease of skin tanning: evidence from three two-sample mendelian randomisation studies

Objectives

The present study used publicly available genome-wide association study (GWAS) summary data to perform three two-sample Mendelian randomization (MR) studies, aiming to examine the causal links between gut microbiome and BCC, melanoma skin cancer, ease of skin tanning.

Methods

SNPs associated with exposures to basal cell carcinoma, melanoma skin cancer and ease of skin tanning from the genome-wide association study data of UK Biobank and MRC-IEU (MRC Integrative Epidemiology Unit), and the meta-analysis data from Biobank and MRC-IEU were used as instrumental variables (IVs). The casual estimates were assessed with a two-sample Mendelian randomisation test using the inverse-variance-weighted (IVW) method, Wald ratio, MR-Egger method, maximum likelihood, weighted median, simple mode, and weighted mode.

Results

After the application of MR analysis, diffirent effects of multiple groups of gut microbiota was observed for BCC, melanoma skin cancer and ease of skin tanning. The relationships between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning were supported by a suite of sensitivity analyses, with no statistical evidence of instrument heterogeneity or horizontal pleiotropy. Further investigation is required to explore the relationship between between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning.

Conclusion

Our study initially identified potential causal roles between the gut microbiome and BCC, melanoma skin cancer, ease of skin tanning, and highlighted the role of gut microbiome in the progression of basal cell carcinoma, melanoma skin cancer, ease of skin tanning.

The Protective Effect of a Human Umbilical Cord Mesenchymal Stem Cell Supernatant on UVB-Induced Skin Photodamage

The skin is constantly exposed to a range of environmental stressors, including ultraviolet (UV) radiation, which can cause damage to the skin. Repairing UV-damaged skin has been a major focus of research in recent years. The therapeutic potential of human umbilical cord mesenchymal stem cells (HUCMSCs) exhibits anti-photoaging properties. In this study, we developed a strategy for concentrating an HUCMSC supernatant, and examined the protective effects of CHS on UVB exposure in vitro and in vivo. Our results demonstrate that CHS repairs UVB exposure by promoting cell viability and migration and reducing senescent and apoptosis cells. We further found that the photoprotective effect of CHS is due to autophagy activation. Moreover, CHS reduces wrinkles and senescent cells, increases collagen expression, and improves immune function in UVB exposure-induced skin damage. In summary, our study provides a new approach for repairing cell damage, and suggests that CHS might be a potential candidate for preventing UVB-induced skin photodamage.

Rapamycin protects mouse skin from ultraviolet B-induced photodamage by modulating Hspb2-mediated autophagy and apoptosis

BACKGROUND

Continuous exposure to UVB is the main extrinsic cause of skin photodamage, which is associated with oxidative stress, DNA damage, apoptosis and degradation of collagen. Rapamycin, a mechanistic target inhibitor of rapamycin complex 1 (mTORC1), has been shown to play a crucial role anti-tumor and aging retardation, but its mechanism of action in UVB-induced photodamage still remains unknown. In this study, we investigated the role of rapamycin and Hspb2 (also known as Hsp27) in UVB-induced photodamage in mice.

METHODS AND RESULTS

We constructed skin acute photodamage models on the ears of WT and Hspb2 KO mice, respectively, and administered rapamycin treatment. Histological results showed that knockout of the hspb2 exacerbated the skin damage, as evidenced by thickening of the epidermis, breakage and disruption of collagen fibers and reduction in their number, which is reversed by rapamycin treatment. In addition, hspb2 knockout promoted UVB-induced apoptosis and reduced autophagy levels, with a significant increase in p53 levels and Bax/Bcl-2 ratio, a reduction in LC3II/I ratio and an increase in p62 levels in the KO mice compared to those in WT mice after the same dose of UVB irradiation. Rapamycin was also found to inhibit collagen degradation induced by hspb2 knockdown through activation of the TGF-β/Smad signaling pathway.

CONCLUSIONS

Rapamycin can alleviate skin photodamage from Hspb2 knockout to some extent. It may be a potential therapeutic drug for skin photodamage. In this study, we investigated the role of rapamycin and Hspb2 in UVB-induced photodamage in mice. Histological results showed that knockout of the hspb2 exacerbated the skin damage, as evidenced by thickening of the epidermis, breakage and disruption of collagen fibers and reduction in their number, which is reversed by rapamycin treatment. In addition, hspb2 knockout promoted UVB-induced apoptosis and reduced autophagy levels. Rapamycin was also found to inhibit collagen degradation induced by hspb2 knockdown through activation of the TGF-β/Smad signaling pathway. We conclude that rapamycin and Hspb2 exert a synergistic protective effect in skin photodamage.

Photoinactivation of the bacteriophage PhiX174 by UVA radiation and visible light in SM buffer and DMEM-F12

OBJECTIVE

It has been observed that viruses can be inactivated by UVA radiation and visible light. The aim of this study is to investigate whether a medium that contains a photosensitizer might have an influence on viral reduction under irradiation by UVA, violet or blue light. Test virus is the bacteriophage PhiX174 in the photosensitizer-free SM buffer and DMEM-F12, which contains the known photosensitizer riboflavin.

RESULTS

The determined PhiX174 D90 doses in SM buffer and DMEM were 36.8 J/cm² and 13.6 J/cm² at 366 nm, 153.6 J/cm² and 129.1 J/cm² at 408 nm and 4988 J/cm² and 2477.1 J/cm² at 455 nm, respectively. It can be concluded that the medium has a large influence on the results. This might be caused by the photosensitizer riboflavin in DMEM-F12. As riboflavin is a key component in many cell culture media, irradiation experiments with viruses in cell culture media should be avoided if the investigation of intrinsical photoinactivation properties of viruses is aimed for.