PRDX1 exerts a photoprotection effect by inhibiting oxidative stress and regulating MAPK signaling on retinal pigment epithelium.

BACKGROUND: The purpose of this study was to investigate the photoprotection effect of peroxiredoxin 1 (PRDX1) protein in ultraviolet B (UVB) irradiation-induced damage of retinal pigment epithelium (RPE) and its possible molecular mechanism. METHODS: ARPE-19 cell viability and apoptosis were assessed by MTT assay and flow cytometry, respectively. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the PRDX1 expression. The corresponding kits were employed to measure the levels or activities of lactate dehydrogenase (LDH), 8-hydroxy-2-deoxyguanosine (8-OHdG), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD). Western blotting was applied to examine PRDX1 expression and mitogen-activated protein kinase (MAPK) signaling pathway-related proteins. RESULTS: After exposure to 20 mJ/cm2 intensity of UVB irradiation for 24 h, ARPE-19 cells viability was decreased, the leakage degree of LDH and 8-OHdG were increased, and cell apoptosis was elevated. The expression of PRDX1 was significantly down-regulated in UVB-induced ARPE-19 cells. The low expression of PRDX1 was involved in high irradiation intensity. Overexpression of PRDX1 increased cell activity, decreased cell apoptosis, and LDH as well as 8-OHdG leakage in UVB-induced ARPE-19 cells. In addition to alleviating UVB-induced cell damage, PRDX1 overexpression also inhibited UVB-induced oxidative stress (down-regulation of ROS and MDA levels, up-regulation of GSH-Px and SOD activities) and the activation of MAPK signaling pathway in ARPE-19 cells. CONCLUSION: PRDX1 exerts a photoprotection effect on RPE by attenuating UVB-induced cell damage and inhibiting oxidative stress, which can be attributed to the inhibition of MAPK signaling pathway activation.

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.

Sunscreen Practices and Preferences of Skin of Color Patients.

Sunscreen is an essential way to protect against photodamage from ultraviolet (UV) radiation. Despite the recognized benefits of sunscreen in preventing skin damage from UV light, its use varies across different patient groups. This cross-sectional, questionnaire-based study aims to uncover the sunscreen usage patterns, preferences, and barriers among non-Hispanic White (NHW) and skin of color (SOC) individuals. Our findings demonstrate that NHW individuals are more likely to wear sunscreen daily (31% NHW vs 25% SOC) and reapply sunscreen at least once a day (76% NHW vs 45% SOC) compared with SOC individuals. SOC individuals demonstrate a willingness to use sunscreen, but they face barriers such as cost (2% NHW vs 16% SOC), lack of knowledge in finding suitable products (22% NHW vs 41% SOC), and concerns about white cast (7% NHW vs 25% SOC). SOC individuals are less likely to know the difference between mineral and chemical sunscreen (49% NHW vs 29% SOC), less likely to learn about sunscreen from dermatologists (36% NHW vs 22% SOC), and more likely to prefer sunscreen from brands owned by people of color (13% NHW vs 47% SOC).  In addition to analyzing the broader categories of NHW and SOC, subgroup analysis was conducted on specific subgroups, including Black, Asian, and Hispanic groups. Herein, we highlight differences in motivations, sunscreen preferences, sources of information, and knowledge levels about sun protection between NHW and SOC individuals. By uncovering the unique needs and challenges faced by SOC individuals, we aim to improve culturally competent patient education and promote effective sun protection practices across diverse populations. J Drugs Dermatol. 2024;23(6):456-462.     doi:10.36849/JDD.8268.

Sunproofing from within: A deep dive into oral photoprotection strategies in dermatology.

BACKGROUND: Photoprotection is the first measure in the prevention and treatment of the deleterious effects that sunlight can cause on the skin. It is well known that prolonged exposure to solar radiation leads to acute and chronic complications, such as erythema, accelerated skin aging, proinflammatory and procarcinogenic effects, and eye damage, among others. METHODS: A better understanding of the molecules that can protect against ultraviolet radiation and their effects will lead to improvements in skin health. RESULTS: Most of these effects of the sunlight are modulated by oxidative stress and proinflammatory mechanisms, therefore, the supplementation of substances that can regulate and neutralize reactive oxygen species would be beneficial for skin protection. Current evidence indicates that systemic photoprotection should be used as an adjunctive measure to topical photoprotection. CONCLUSION: Oral photoprotectors are a promising option in improving protection against damage induced by UVR, as they contain active ingredients that increase the antioxidant effects of the body, complementing other photoprotection measures. We present a review of oral photoprotectors and their effects.

Comprehensive studies reveal physiological and genetic diversity in traditional rice cultivars for UV-B sensitivity.

Acclimation to crop niches for thousands of years has made indigenous rice cultivars better suited for stress-prone environments. Still, their response to UV-B resiliency is unknown. 38 rice landraces were grown in cemented pots in a randomised block design with three replicates under open field conditions in Sambalpur University in the wet season of 2022. Half of the plants in each of the cultivars were administered UV-B radiation at the panicle emergence stage in an adjustable UV-B chamber permitting sunlight, and the effects of the stress on various morpho-physiological features, such as spikelet sterility, flag leaf photosynthetic and flavonoid pigment contents, and lipid peroxidation activities, were estimated for calibration of stress resistance. The experiment identified Swarnaprabha and Lalkain as the most sensitive and resilient to stress respectively, and the differential response between them was further revealed in the expression of genes related to UV-B sensitivity. Subject to the stress, Swarnaprabha exhibited symptoms of injuries, like leaf burns, and a higher loss of various photosynthetic parameters, such as pigment contents, SPAD and Fv/Fm, ETR and qP values, while NPQ increased only in Lalkain. Exposure to UV-B increased the total phenolic and flavonoid contents in Lalkain while depressing them in Swarnaprabha. Such an effect amounted to a higher release of fluorescent energy in the latter. The levels of expression of gene families controlling flavonoid activation and UV-B signal transduction, such as OsWRKY, OsUGT, OsRLCK, OsBZIP, OsGLP, and CPD photolyase were similar in both the cultivars in the control condition. However, exposure to UV-B stress overexpressed them in resilient cultivars only. The magnitude of expression of the genes and the impact of the stress on photosynthetic parameters, phenolic compounds and pubescent hair structure at the panicle emergence stage could be valid indicators among indigenous rice for UV-B tolerance.

Annexin A1 protects epidermal stem cells against ultraviolet-B irradiation-induced mitochondrial dysfunction.

Ultraviolet-B (UV-B) radiation overexposure causes function impairment of epidermal stem cells (ESCs). We explored the mechanism of Annexin A1 (ANXA1) ameliorating UV-B-induced ESC mitochondrial dysfunction/cell injury. ESCs were cultured in vitro and irradiated with different doses of UV-B. Cell viability/ANXA1 protein level were assessed. After oe-ANXA1 transfection, ESCs were treated with oe-ANXA1/UV-B irradiation/CCCP/CCG-1423/3-methyladenine for 12 h. Cell viability/death, and adenosine triphosphate (ATP)/reactive oxygen species (ROS) levels were determined. Mitochondrial membrane potential (MMP) changes/DNA (mtDNA) content/oxygen consumption and RhoA activation were assessed. ROCK1/p-MYPT1/MYPT1/(LC3BII/I)/Beclin-1/p62 protein levels were determined. Mitochondrial morphology was observed. Mito-Tracker Green (MTG) and LC3B levels were determined. UV-B irradiation decreased cell viability/ANXA1 expression in a dose-dependent manner. UV-B-treated ESCs exhibited reduced cell viability/ATP content/MMP level/mitochondrial respiratory control ratio/mtDNA number/RhoA activity/MYPT1 phosphorylation/MTG+LC3B+ cells/(LC3BII/I) and Beclin-1 proteins, increased cell death/ROS/p62/IL-1ß/IL-6/TNF-α expression, contracted mitochondrial, disappeared mitochondrial cristae, and increased vacuolar mitochondria, which were averted by ANXA1 overexpression, suggesting that UV-B induced ESC mitochondrial dysfunction/cell injury/inflammation by repressing mitophagy, but ANXA1 promoted mitophagy by activating the RhoA/ROCK1 pathway, thus repressing UV-B's effects. Mitophagy activation ameliorated UV-B-caused ESC mitochondrial dysfunction/cell injury/inflammation. Mitophagy inhibition partly diminished ANXA1-ameliorated UV-B's effects. Conjointly, ANXA1 promoted mitophagy by activating the RhoA/ROCK1 pathway, thereby improving UV-B-induced ESC mitochondrial dysfunction/cell injury.

Reduction of Campylobacter jejuni contamination by using UVA-LED and sodium hypochlorite on the surface of chicken meat.

Campylobacter jejuni causes gastroenteritis in humans and is a major concern in food safety. Commercially prepared chicken meats are frequently contaminated with C. jejuni, which is closely associated with the diffusion of intestinal contents in poultry processing plants. Sodium hypochlorite (NaClO) is commonly used during chicken processing to prevent food poisoning; however, its antimicrobial activity is not effective in the organic-rich solutions. In this study, we investigated the potential of a new photo-disinfection system, UVA-LED, for the disinfection of C. jejuni-contaminated chicken surfaces. The data indicated that UVA irradiation significantly killed C. jejuni and that its killing ability was significantly facilitated in NaClO-treated chickens. Effective inactivation of C. jejuni was achieved using a combination of UVA and NaClO, even in the organic-rich condition. The results of this study show that synergistic disinfection using a combination of UVA and NaClO has potential beneficial effects in chicken processing systems.

A prospective cohort study exploring the joint influence of sunlight exposure and tanning bed use on basal cell carcinoma, squamous cell carcinoma, and melanoma risk.

Exposure to solar ultraviolet (UV) radiation and use of UV-emitting tanning devices are known risk factors for skin cancer. Few studies have explored the interaction between these risk factors, namely how the risk of skin cancer increases among those who both have been exposed to high levels of natural sunlight and regularly use tanning beds. Nurses' Health Study II followed 116,430 women, aged 25-42, from 1991 to 2011. Cumulative average UV exposure was based on participants' residences at follow-up periods. History of severe sunburn during ages 15-20 was used as a proxy for early-life sunlight exposure. Tanning bed use in early life data was collected. Participants reported melanoma, basal cell carcinoma (BCC), and squamous cell carcinoma (SCC) diagnoses. We built multivariable Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of skin cancer associated with joint effects of sunlight exposure and tanning bed use. Participants with high sunlight exposure and tanning bed use during high school/college had an increased risk of BCC (HR = 1.53, 95% CI 1.37-1.71, Pinteraction=0.01; vs. low sun exposure and no tanning bed use). Participants with a history of severe sunburns and tanning bed use during high school/college were at increased risk of BCC (HR = 1.62, 95% CI 1.47-1.79, Pinteraction=0.02; vs. no sunburns and no tanning bed use). No significant interactions were found between sunlight exposure and tanning bed use on SCC and melanoma risk. We found significant interactions between sunlight exposure and tanning bed use on the risk of BCC.

Skin cancers are the most frequent cancers in fair-skinned populations, but we can prevent them.

Cancers of the skin are the most commonly occurring cancers in humans. In fair-skinned populations, up to 95% of keratinocyte skin cancers and 70-95% of cutaneous melanomas are caused by ultraviolet radiation and are thus theoretically preventable. Currently, however, there is no comprehensive global advice on practical steps to be taken to reduce the toll of skin cancer. To address this gap, an expert working group comprising clinicians and researchers from Africa, America, Asia, Australia, and Europe, together with learned societies (European Association of Dermato-Oncology, Euromelanoma, Euroskin, European Union of Medical Specialists, and the Melanoma World Society) reviewed the extant evidence and issued the following evidence-based recommendations for photoprotection as a strategy to prevent skin cancer. Fair skinned people, especially children, should minimise their exposure to ultraviolet radiation, and are advised to use protective measures when the UV index is forecast to reach 3 or higher. Protective measures include a combination of seeking shade, physical protection (e.g. clothing, hat, sunglasses), and applying broad-spectrum, SPF 30 + sunscreens to uncovered skin. Intentional exposure to solar ultraviolet radiation for the purpose of sunbathing and tanning is considered an unhealthy behaviour and should be avoided. Similarly, use of solaria and other artificial sources of ultraviolet radiation to encourage tanning should be strongly discouraged, through regulation if necessary. Primary prevention of skin cancer has a positive return on investment. We encourage policymakers to communicate these messages to the general public and promote their wider implementation.

UVB radiation exposure modulates mitophagy in embryonic cells of freshwater prawn Macrobrachium olfersii: Exploring a protective organelle quality control mechanism.

Aquatic environments are subject to ultraviolet B (UVB) radiation incidence, and its effects on organisms are dose-dependent. Besides DNA, mitochondria are an important target of this radiation that causes structural damage and impairs its functional dynamics. Here, we hypothesize that mitophagy acts as an organelle quality control mechanism to mitigate UVB impacts in embryonic cells. Then, freshwater prawn Macrobrachium olfersii embryos was used as a model to investigate the effects of UVB on genes (Tomm20, Opa1, Pink, Prkn, Sqstm1, and Map1lc3) and proteins (TOM20, PINK1, p62 and LC3B) involved in mitophagy modulation. The choice of genes and proteins was based on the identification of mitochondrial membrane (Tomm20, Opa1 and TOM20), mediation of mitophagy (Pink1, Prkn and PINK1), and recognition of mitochondria by the autophagosome membrane (Sqstm1, Map1lc3, p62 and LC3B). First, the phylogeny of all genes presented bootstrap values >80 and conserved domains among crustacean species. Gene expression was inherently modulated during development, with transcripts (Tomm20, Opa1, Pink, Prkn, Sqstm1, and Map1lc3) overexpressed in the initial and final stages of development. Moreover, UVB radiation induced upregulation of Tomm20, Opa1, Pink, Prkn, Sqstm1, and Map1lc3 genes at 6 h after exposure. Interestingly, after 12 h, the protein content of PINK1, p62, and LC3B increased, while TOM20 was not responsive. Despite UVB radiation's harmful effects on embryonic cells, the chronology of gene expression and protein content indicates rapid activation of mitophagy, serving as an organelle quality control mechanism, given the analyzed cells' integrity.

The extract of buds of Chrysanthemum morifolium ramat alleviated UVB-induced skin photoaging by regulating MAPK and Nrf2/ARE pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Chrysanthemum morifolium Ramat. is a commonly used Chinese herb and food homologous plant with traditional effects such as anti-inflammatory, antifebrile, antibacterial and antiviral. AIM OF STUDY: Photoaging is one of the main causes of accelerated skin aging. Chrysanthemum morifolium Ramat. has reported to alleviate photodamage. In this study, we investigated the protective effect of the extract of buds of Chrysanthemum morifolium Ramat. (CE) on UVB-induced photoaging and further mechanism. MATERIALS AND METHODS: The extract of buds of chrysanthemum was analyzed by HPLC-Q-TOF-MS/MS. Antioxidant activity was assessed by DPPH and ABTS assay. Cell viability examined by cell counting kit-8 assay. The ROS level was detected by fluorescent probe DCFH-DA. Protein expression evaluated by Western blotting. The skin tissue investigated by immunohistochemistry. RESULTS: CE significantly reversed the decrease of cell viability that induced by UVB in HaCaT and HFF-1 cells. Further analysis showed that CE alleviated photoaging by inhibiting the expression of mitogen-activated protein kinase (MAPK) and activating the NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway to promote the expression of antioxidant enzymes. Moreover, CE effectively improved the reduced skin hydration, disordered collagen and thickening epidermis caused by UVB in mice. CONCLUSIONS: All results demonstrated that CE had therapeutic effect on UVB-induced photoaging and provided theoretical basis for its further developing as a natural functional product with anti-photoaging effect.

Tokishakuyakusan alleviates ultraviolet-induced skin pigmentation by decreasing the expression of melanogenesis-related enzymes.

ETHNOPHARMACOLOGICAL RELEVANCE: Tokishakuyakusan (TSS), a traditional Kampo medicine, can effectively alleviate symptoms unique to women, such as menstrual pain and menopausal symptoms, and this effect is believed to be related to its ability to increase the secretion of female hormones. TSS is also believed to be effective against skin pigmentation. However, no studies have examined the effect of TSS on pigmentation. AIM OF THE STUDY: In this study, we conducted basic research to determine the effects of TSS on pigmentation. MATERIALS AND METHODS: Female HRM-2 mice were given free access to a normal diet or a TSS-containing diet for 7 weeks. For 3 weeks starting from the 4th week of treatment, the back of the skin was irradiated with ultraviolet (UV) light, and the melanin level was measured. The expression levels of melanogenesis-related genes and inflammatory markers in the skin were analyzed. RESULTS: The melanin level in the skin of the mice exposed to UV radiation was approximately three times greater than that in the skin of the mice in the non-UV-irradiated group, confirming pigmentation due to UV irradiation. The protein expression levels of tyrosinase (Tyr), tyrosinase-related protein-1 (Tyrp1), and dopachrome tautomerase (Dct), which are important for melanin production, were significantly greater in the UV irradiation group than in the non-UV irradiation group. In contrast, the amount of skin melanin in the mice treated with TSS was significantly lower than that in the UV-irradiated group, and the expression levels of melanogenesis-related enzymes were also lower. Furthermore, TSS significantly decreased the expression of microphthalmia transcription factor (Mitf), a transcription factor for melanogenesis-related enzymes, and the inflammatory cytokines interleukin-1ß and interleukin-6. CONCLUSIONS: TSS inhibits melanin production in melanocytes by suppressing the increase in the expression of melanogenesis-related enzymes caused by UV irradiation. These findings suggested that this effect of TSS is exerted through the combined regulation of MITF expression and anti-inflammatory responses.

Orbea variegata (L.) Haw in skin carcinogenesis: insights from an in vivo male Swiss mouse model study.

Skin cancer is the most widespread type of malignant tumor representing a major public health concern. Considering the numerous side effects associated with conventional treatments, phytotherapy may be regarded as a viable medicinal alternative. This study aimed to investigate the therapeutic potential of Orbea variegata (L.) Haw, an ornamental plant, in treating skin cancer using an animal model induced by a combination of ultraviolet (UV) irradiation and sulfuric acid treatment. The hydroethanolic extract of Orbea variegata underwent phytochemical characterization, identifying the presence of reducing sugars, coumarins, alkaloids, flavonoids, tannins, and saponins through qualitative screening. Quantitative analysis demonstrated significant amounts of phenolic compounds (29.435 ± 0.571 mg GAE/g of dry extract), flavonoids (6.711 ± 0.272 mg QE/g of dry extract), and tannins (274.037 ± 11.3 mg CE/g of dry extract). The administration the hydroethanolic extract in two concentrations (1 or 2 g/kg) to male Swiss mice exhibited no marked adverse effects, as evidenced by serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzyme activity levels. In addition, the extract significantly reduced skin hyperplasia and inflammation induced by UV/sulfuric acid treatment as noted in tissue analyses and decreased protein expression of nuclear proliferation marker (Ki-67). This improvement was associated with a marked decrease in oxidative stress, as indicated by diminished lipid peroxidation levels, and restoration of the activity of endogenous antioxidant enzyme catalase (CAT) to control levels. Our findings demonstrated the potential of Orbea variegata hydroethanolic extract to be considered as a treatment for skin cancer, exhibiting its apparent safety and efficacy in reducing inflammation and carcinogenesis in a UV/sulfuric acid-induced Swiss mouse model, attributed to its phytochemical content and associated antioxidant activities.

Overexposure to ultraviolet radiation in solar urticaria.

A man in his 50s was diagnosed with solar urticaria following monochromated light testing that demonstrated exquisite photosensivity to ultraviolet (UV) A, UV B (UVB) and visible light.Treatment options for this photodermatosis are limited; UVB phototherapy is one modality that can be appropriate in some patients. This is administered at very low doses in a controlled environment to induce skin hardening.1 To self-treat his condition, the patient used a commercial sunbed on two occasions several days apart. He noted an immediate flare of solar urticaria after first use with associated dizziness. Following the second use, he felt generally unwell and was witnessed to lose consciousness and displayed jerky movements of his limbs while a passenger in a car. Investigations including a head MRI and an EEG were normal; an anoxic seizure caused by a flare of solar urticaria was later confirmed.Solar urticaria is a rare photodermatosis that is poorly understood and difficult to treat. The condition has a significant impact on the quality of life of patients. Severe cases can be associated with systemic symptoms that could be life-threatening.

Salvianolic acid B protects against UVB-induced skin aging via activation of NRF2.

BACKGROUND: Prolonged exposure to sun radiation may result in harmful skin photoaging. Therefore, discovering novel anti-photoaging treatment modalities is critical. An active component isolated from Salvia miltiorrhiza (SM), Salvianolic acid B (Sal-B), is a robust antioxidant and anti-inflammatory agent. This investigation aimed to discover the therapeutic impact and pathways of salvianolic acid B for UVB-induced skin photoaging, an area that remains unexplored. METHODS: We conducted in vitro experiments on human dermal fibroblasts (HDFs) exposed to UVB radiation, assessing cellular senescence, superoxide dismutase (SOD) activity, cell viability, proliferation, migration, levels of reactive oxygen species (ROS), and mitochondrial health. The potential mechanism of Sal-B was analyzed using RNA sequencing, with further validation through Western blotting, PCR, and nuclear factor erythroid 2-related factor 2 (NRF2) silencing methods. In vivo, a model of skin photoaging induced by UVB in nude mice was employed. The collagen fiber levels were assessed utilizing hematoxylin and eosin (H&E), Masson, and Sirus red staining. Additionally, NRF2 and related gene and protein expression levels were identified utilizing PCR and Western blotting. RESULTS: Sal-B was found to significantly counteract photoaging in UVB-exposed skin fibroblasts, reducing aging-related decline in fibroblast proliferation and an increase in apoptosis. It was observed that Sal-B aids in protecting mitochondria from excessive ROS production by promoting NRF2 nuclear translocation. NRF2 knockdown experiments established its necessity for Sal-B's anti-photoaging effects. The in vivo studies also verified Sal-B's anti-photoaging efficacy, surpassing that of tretinoin (Retino-A). These outcomes offer novel insights into the contribution of Sal-B in developing clinical treatment modalities for UVB-induced photodamage in skin fibroblasts. CONCLUSION: In this investigation, we identified the Sal-B protective impact on the senescence of dermal fibroblasts and skin photoaging induced by radiation of UVB. The outcomes suggest Sal-B as a potential modulator of the NRF2 signaling pathway.

Formulation and Characterization of Ethosomes for Transdermal Delivery of Prinsepia Utilis Rogle Seed Oil with Ameliorative Effects against UVB-Induced Skin Damage.

Prinsepia utilis seed oil (PUSO) is a natural medication obtained from Prinsepia utilis Rogle seed, which has been used for the treatment of skin diseases. The study aims to prepare ethosomes with high drug loading as a water-soluble transdermal vehicle to enhance the transdermal delivery of PUSO. PUSO-loaded ethosomes (PEs) were prepared using a cold method, and optimized by an orthogonal experimental design with entrapment efficiency (EE) as the dependent variable. The PEs prepared with the optimized formulation showed good stability, with a spherical shape under transmission electron microscopy (TEM), average particle size of 39.12 ± 0.85 nm, PDI of 0.270 ± 0.01, zeta potential of -11.3 ± 0.24 mV, and EE of 95.93 ± 0.43%. PEs significantly increased the skin deposition of PUSO compared to the PUSO suspension (P < 0.001). Moreover, the optimum formula showed significant ameliorative effects on ultraviolet B (UVB) irradiation-associated macroscopic and histopathological changes in mice skin. Therefore, PEs represent a promising therapeutic approach for the treatment of UVB-induced skin inflammation, with the potential for industrialization.

Naringenin, a flavanone constituent from Sea buckthorn pulp extract, prevents ultraviolet (UV)-B radiation-induced skin damage via alleviation of impaired mitochondrial dynamics mediated inflammation in human dermal fibroblasts and Balb/c mice models.

Ultraviolet-B (UV-B) irradiation has been reported to cause oxidative stress and inflammation-mediated skin photo-damage. Furthermore, mitochondrial dynamics have been implicated to play a critical role in these processes. For the first time, we describe in this study how UVB-induced aberrant mitochondrial dynamics and inflammation interact in primary human dermal fibroblasts (HDFs). Our findings demonstrated that UV-B irradiation induced -impairment in mitochondrial dynamics by increasing mitochondrial fragmentation in HDFs. Imbalanced mitochondrial dynamics lead to the activation of NFкB and pro-inflammatory cytokines. The current study further aimed to investigate the protective effect of Naringenin (a naturally occurring flavonoid isolated from Sea buckthorn fruit pulp) against UV-B-induced mitochondrial fragmentation and inflammation in HDFs and Balb/c mice. Although Naringenin has been shown to have anti-inflammatory and antioxidant potential, its effects and mechanisms of action on UVB-induced inflammation remained unclear. We observed that Naringenin restored the UV-B-induced imbalance in mitochondrial fission and fusion in HDFs. It also inhibited the phosphorylation of NFкB and reduced the generation of pro-inflammatory cytokines. Naringenin also alleviated UV-B-induced oxidative stress by scavenging the reactive oxygen species and up-regulating the cellular antioxidant enzymes (Catalase and Nrf2). Topical application of Naringenin to the dorsal skin of Balb/c mice exposed to UV-B radiation prevented mitochondrial fragmentation and progression of inflammatory responses. Naringenin treatment prevented neutrophil infiltration and epidermal thickening in mice's skin. These findings provide an understanding for further research into impaired mitochondrial dynamics as a therapeutic target for UV-B-induced inflammation. Our findings imply that Naringenin could be developed as a therapeutic remedy against UVB-induced inflammation.

Continuing benefits of the Montreal Protocol and protection of the stratospheric ozone layer for human health and the environment.

The protection of Earth's stratospheric ozone (O3) is an ongoing process under the auspices of the universally ratified Montreal Protocol and its Amendments and adjustments. A critical part of this process is the assessment of the environmental issues related to changes in O3. The United Nations Environment Programme's Environmental Effects Assessment Panel provides annual scientific evaluations of some of the key issues arising in the recent collective knowledge base. This current update includes a comprehensive assessment of the incidence rates of skin cancer, cataract and other skin and eye diseases observed worldwide; the effects of UV radiation on tropospheric oxidants, and air and water quality; trends in breakdown products of fluorinated chemicals and recent information of their toxicity; and recent technological innovations of building materials for greater resistance to UV radiation. These issues span a wide range of topics, including both harmful and beneficial effects of exposure to UV radiation, and complex interactions with climate change. While the Montreal Protocol has succeeded in preventing large reductions in stratospheric O3, future changes may occur due to a number of natural and anthropogenic factors. Thus, frequent assessments of potential environmental impacts are essential to ensure that policies remain based on the best available scientific knowledge.

Carcinogenic risk in patients treated with UVA-1 phototherapy: A 5-year retrospective study.

BACKGROUND: UVA-1 phototherapy was first used to treat atopic dermatitis and afterwards to several other skin diseases. The contribution of UVA-1 in human photocarcinogenesis, skin photoaging, immune suppression, and hyperpigmentation is now well established. The actual contribution of UVA-1 radiation to the development of malignant melanoma (MM) in humans cannot be excluded. PURPOSE: The aim of the study is to evaluate the risk of developing skin cancers (non-melanoma skin cancers (NMSCs) and MM) in patients treated with UVA-1 phototherapy with a 5-year dermatological follow-up. METHODS: We conducted a retrospective cohort study with 31 patients with morphea and atopic dermatitis treated with medium dose UVA-1 phototherapy (34 J/cm2). All enrolled patients underwent an oncologic prevention visit annually with a 5-year follow-up with clinical evaluation of the entire skin surface. RESULTS: During the 5-year follow-up, we recorded a case of basal cell carcinoma (BCC) in the cervical region and one case of MM on the back (pT1a). In both cases, the patients were female and affected by morphea. The Glogau 3 group is prevalent (42%), which is consistent with moderate to severe aging; the data appear to be compatible with the age. CONCLUSIONS: This study attests that medium-dose UVA-1 phototherapy does not increase the risk of developing skin tumors and that UVA-1 phototherapy is not a worsening factor of facial photoaging. The main limitation of the study is the small sample size, avoiding to obtain statistically significant values. It was not possible to analyze individually the actual daily sun exposure during the 5-year observation period and to correlate it in terms of time and tumor development. Further studies with large sample sizes will be needed to confirm our data. Our study reaffirms how the dermatological examination performed annually is essential in the follow-up of patients undergoing this type of therapy.

Cancer Incidence Rates in the US in 2016-2020 with Respect to Solar UVB Doses, Diabetes and Obesity Prevalence, Lung Cancer Incidence Rates, and Alcohol Consumption: An Ecological Study.

This article reports the results of an ecological study of cancer incidence rates by state in the US for the period 2016-2020. The goals of this study were to determine the extent to which solar UVB doses reduced cancer risk compared to findings reported in 2006 for cancer mortality rates for the periods 1950-1969 and 1970-1794 as well as cancer incidence rates for the period 1998-2002 and to determine which factors were recently associated with cancer risk. The cancer data for non-Hispanic white (European American) men and women were obtained from the Centers for Disease Control and Prevention. Indices were obtained for solar UVB at the surface for July 1992, and alcohol consumption, diabetes, and obesity prevalence near the 2016-2020 period. Lung cancer incidence rates were also used in the analyses as a surrogate for smoking, diet, and air pollution. The cancers for which solar UVB is significantly associated with reduced incidence are bladder, brain (males), breast, corpus uteri, esophageal, gastric, non-Hodgkin's lymphoma, pancreatic, and renal cancer. Lung cancer was significantly associated with colorectal, laryngeal, and renal cancer. Diabetes was also significantly associated with breast, liver, and lung cancer. Obesity prevalence was significantly associated with breast, colorectal, and renal cancer. Alcohol consumption was associated with bladder and esophageal cancer. Thus, diet has become a very important driver of cancer incidence rates. The role of solar UVB in reducing the risk of cancer has been reduced due to people spending less time outdoors, wearing sunscreen that blocks UVB but not UVA radiation, and population increases in terms of overweight and obese individuals, which are associated with lower 25-hydroxyvitamin D concentrations and the generation of systemic inflammation, which is a risk factor for cancer. A dietary approach that would reduce the risk of diabetes, obesity, lung cancer, and, therefore, cancer, would be one based mostly on whole plants and restrictions on red and processed meats and ultraprocessed foods. Solar UVB exposure for a few minutes before applying sunscreen and taking vitamin D supplements would also help reduce the risk of cancer.