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

Microplastics (MP) are a global concern due to their small size, insolubility in water, and non-degradable nature, and long-term environmental persistence. Weathering processes, such as ultraviolet (UV) radiation, can alter their properties, enhancing their ability to absorb pollutants or release harmful substances, such as pesticides, which is also an environmental concern, thereby complicating their environmental impact and mitigation efforts. This study investigates the impact of UVB-induced photoaging on polyethylene (PE) microplastics and their sorption behavior towards the pesticide chlorpyrifos (CP). PE microplastics were exposed to varying UVB aging durations, leading to significant changes in their physicochemical and morphological properties. The sorption experiments revealed that aged microplastics exhibited increased affinity for CP, with adsorption capacity rising by 17.9% compared to pristine PE. This enhanced adsorption was attributed to the (1) introduction of oxygen-containing functional groups, facilitating the formation of hydrogen bonds between the microplastic surface and surrounding water molecules, thereby contributing to the adsorption of CP; (2) formation of irregular micropores and surface roughness, potentially providing ample sites for pesticide adsorption and (3) reduction in crystallinity from 35% to 30%, which favors the sorption of hydrophobic organic pollutants. Density Functional Theory (DFT) calculations supported these findings by showing changes in the electronic structure of PE that facilitate interactions with CP. These results provide critical insights into the environmental behavior of aged microplastics and their potential to adsorb hazardous chemicals, underscoring the need for further research on the environmental impact of microplastic aging. • UVB aging increases the sorption affinity of PE microplastics to chlorpyrifos. • Photodegradation induces surface roughness and micropore formation on polyethylene. • Aging decreases PE crystallinity, enhancing hydrophobic pollutant adsorption. • Increased oxygen-containing groups on aged PE enhance pesticide adsorption. • DFT calculations reveal changes in polyethylene's electronic structure. [ABSTRACT FROM AUTHOR]

The present study demonstrates biotechnological applications of the lichen Pleurosticta acetabulum , specifically the production of large amounts of hydrogen even after the lichen exposure to extreme conditions such as a) extreme UVB radiation (1.7 mW/cm2 = 1000 J m−2 min−1) over different time periods (4, 20 & 70 h) and b) combined exposure of the lichen to high intensity UVB radiation and extreme low (−196 °C) or extreme high temperatures (+70 °C). The results highlight that the extremophilic and polyextremophilic behavior of lichens both in dehydrated and in regenerated form, under extreme conditions not necessarily recorded on earth, is compatible with their biotechnological uses. The lichen viability was measured using fluorescence induction techniques (OJIP-test), which record changes in the molecular structure and function of the photosynthetic mechanism, while its ability to produce molecular hydrogen was measured through thermal conductivity gas chromatography (GC-TCD) analysis. Hydrogen is a promising fuel for the future. The exciting result of a lichen micro-ecosystem is its ability to expel its moisture and remain in an inactive state, protecting itself from extreme conditions and maintaining its ability to high yield hydrogen production in a closed system, with the sole addition of water and without the need for additional energy. Our results expand the potential use of lichens for future biotechnological applications in extreme Earth environments, but also in environments on other planets, such as Mars, thus paving the way for astrobiotechnological applications. • Lichens produce H 2 even after exposure to extreme temperatures and UVB radiation. • Biotechnological applications of lichens even in extreme environments. • Extremophilic behavior of lichens support astrobiotechnological applications. [ABSTRACT FROM AUTHOR]

Accumulation of secondary metabolites may exhibit developmentally regulated variation in different plant organs. Moreover, prevailing environmental conditions may interact with development-related variations in plant traits. In this study, we examined developmentally regulated variation in phenolic accumulation in the twigs of dioecious Populus tremula (L.) and how the effects of elevated temperature and ultraviolet B (UVB) radiation on growth and phenolics accumulation varied as the plants get older. In an open-field experiment, six female and six male genotypes were exposed to single and combined elevated temperature and UVB radiation treatments for three consecutive growing seasons. The concentrations of low molecular weight phenolics and condensed tannins did not show age-dependent variation in the twigs. In temperature-treated plants, diameter growth rate decreased, and concentration of condensed tannins increased as plants aged; there were no cumulative effects of elevated UVB radiation on growth and phenolic accumulation. Females maintained a higher concentration of low molecular weight phenolics throughout the experimental period; however, growth and phenolic concentration did not vary over time in females and males. Our results suggest that phenolic accumulation in perennial plants may not necessarily always exhibit age-dependent variation and the effects of elevated temperature on growth and phenolic may diminish as plants get older. • Low molecular weight phenolics and condensed tannins did not show age-dependent variation. • In temperature-treated plants, diameter growth rate decreased, and condensed tannins increased as plants aged. • Elevated UVB radiation had no cumulative effect on growth or phenolic concentration. • Growth and phenolic concentration did not vary over time in females and males. [ABSTRACT FROM AUTHOR]

• Intrinsic defence mechanisms of the skin can be augmented with external agents against UVR-induced skin damage. • IGF-I protects skin cells against UVBR-induced damage via IGF-1R-mediated downstream signalling cascades. • The potential of growth factor-based therapies for photodamage are currently being explored. Chronic exposure of human skin to solar ultraviolet radiation (UVR) induces a range of biological reactions which may directly or indirectly lead to the development of skin cancer. In order to overcome these damaging effects of UVR and to reduce photodamage, the skin's endogenous defence system functions in concert with the various exogenous photoprotectors. Growth factors, particularly insulin-like growth factor-I (IGF-I), produced within the body as a result of cellular interaction in response to UVR demonstrates photoprotective properties in human skin. This review summarises the impact of UVR-induced photolesions on human skin, discusses various endogenous as well as exogenous approaches of photoprotection described to date and explains how IGF-I mediates UVR photoprotective responses at the cellular and mitochondrial level. Further, we describe the current interventions using growth factors and propose how the knowledge of the IGF-I photoprotection signalling cascades may direct the development of improved UVR protection and remedial strategies. [ABSTRACT FROM AUTHOR]

Many studies have investigated the effects of one or two environmental factors on methane (CH 4) emissions from plants at a single growth stage, but the impact that multiple co-occurring stress factors may have on emissions at different growth stages has rarely been studied. The objective of this study was to examine the effects of temperature, ultraviolet-B (UVB) radiation, and watering regime on CH 4 emissions and some relevant physiological characteristics of pea (Pisum sativum L. cv. 237 J Sundance) plants at three growth stages. We grew plants under two temperature regimes (22/18 °C and 28/24 °C; 16 h light/8 h dark), two UVB levels [0 and 5 kJ m−2 d−1] and two watering regimes (well-watered, watering plants to field capacity, and water-stressed, watering plants at wilting point). Measurements were then taken after 10, 20, and 30 days of growth under experimental conditions, following seven days of initial growth under 22/18 °C. Higher temperatures, UVB5, and water stress adversely affected photosynthesis and chlorophyll fluorescence, but increased CH 4 emissions, which decreased with increased plant age. Also, interaction of higher temperatures and UVB5 reversed the pattern of CH 4 emissions at growth stages, compared to that of other treatments. We conclude that CH 4 emission decreases with plant age, and it is affected by stress factors through changes in physiological activities of plants. • Examining the effects of multiple stress factors on methane emissions from plants is important. • High temperature, UVB radiation and water stress adversely affect plant physiological processes. • Aerobic methane emission is increased by environmental stressors, but decreased with plant age. • This study has important implications for the estimation of global methane fluxes from vegetation. [ABSTRACT FROM AUTHOR]

Ready-To-Eat (RTE) salads conveniently pre-prepared in bags can promote the intake of natural bioactive compounds, including antivirals such as quercetin. However, the content of these compounds in the species used for RTE salads is usually low due to limited solar UV exposure under tunnels and greenhouses in which they are usually cultivated. To address this, we treated commercial fresh-cut lettuce (Lactuca sativa L.) and wild rocket (Diplotaxis tenuifolia L.) leaves using a narrow-band UVB lamp directly through sealed polypropylene bags during storage (5–6 °C, 80% RH). The bagged leaf samples were kept under 20 µmol m−2 s−1 of white light with a 12 h photoperiod for 6 d. Half of the samples were additionally treated, 9 h d−1, during the first 3 d by UVB narrow-band lamps delivering 2.8–3.6 μmol m−2s−1 of UVB and 0.8–1.0 μmol m−2s−1 of UVA radiation. The effects of the UVB treatments on epidermal phenolics, chlorophyll and photosynthetic parameters were monitored daily by non-destructive fluorescence sensors over a 6-d storage period. At the end of the experiment, destructive HPLC-DAD analysis of phenolics and photosynthetic pigments, antioxidant capacity assays and fresh weight loss determinations were conducted. The UVB-treatment increased the epidermal phenolics (EPhen) Index with respect to unirradiated controls, while not affecting chlorophyll and carotenoids levels as well as photosynthetic efficiency. For both species, the EPhen Index changes were detected 15 h after the first UVB application. Then, wild rocket responded faster than baby-leaf lettuce and reached the maximal phenolic level with less than 1/3 of the energy dose needed by lettuce. UVB-treated samples exhibited higher flavonoid concentrations (mainly quercetin derivatives) compared to controls (48–67% and 37–66% in lettuce and wild rocket, respectively). Leaf chlorophyll and carotenoid contents were not affected by both UVB treatment and storage. We proved, for the first time, that it is possible to treat RTE salad leaves using through-packaging UVB radiation and enhance their total phenolic and quercetin derivative contents. We also provided more insights concerning the dynamics of the UVB-elicitation of phenolic compounds in postharvest leaves. Our results are propaedeutic for the optimization of potential UVB-treatments; selection of the most efficient wavelengths, intensity, single/multiple doses and proposals for application in the food industry. [Display omitted] • Through-packaging UVB irradiation enhances quercetins in ready-to-eat salads. • Postharvest non-destructive optical assessment of phenolics in salad samples. • Pigments and photosynthesis of stored salads are not affected by UVB treatments. • UVB treatments do not affect fresh weight and antioxidant activity of stored salads. [ABSTRACT FROM AUTHOR]

Abstract Natured botanical extract has attracted considerable attention recently in the field of skin anti-ultraviolet (UV) radiation. As a medicinal herb, Sophora japonica flower buds contained several components such as flavonoids, isoflavonoids, triterpenes, alkaloids and polysaccharides, which have multiple pharmacological properties except hemostatic agents which have been used in China and Korea for centuries. The purpose of our study was to investigate whether polysaccharide extracted from Sophora japonica L. flower buds (PS) was able to attenuate UVB-induced damage using a human keratinocyte cell line (HaCaT cells). HaCaT cells were pretreated with PS in a serum-free medium for 2 h and then irradiated with different doses of UVB rays. The results showed that the PS attenuated UVB-induced cytotoxicity which was verified by MTT method and morphology feature assay. UVB exposure (30–120 mJ/cm2) reduced HaCaT cells viability significantly following with the increased irradiation dose 24 h later, while pretreatment with PS (0.25–2.0 mg/mL) attenuated UVB-induced cytotoxicity significantly and increased cell viability in a dose-dependent manner except 30 mJ/cm2 group. The PS reduced the ROS generation, down-regulated the expression of phosphor-JNK and phosphor-p38 MAPK proteins significantly through MAPK pathway in UVB-irradiated HaCaT cells. It also decreased the apoptosis rate at low dose of UVB ray and protected the cells from apoptosis which had been identified by the down-regulated level of active-caspase3 in UVB-irradiated HaCaT cells. In conclusion, PS pretreatment protected HaCaT keratinocytes from UVB irradiation-induced skin injuries effectively, and the underlying mechanism may involve MAPK signaling pathway which contribute to apoptotic cell death. However, further studies especially whose using human systems are needed to determine efficacy of PS in vivo. Graphical Abstract Unlabelled Image Highlights • Polysaccharide from Sophora japonica flower buds decreases UVB-induced cytotoxicity. • The polysaccharide significantly reduces UVB-induced ROS generation. • The Polysaccharide decreases UVB-induced apoptosis rate. [ABSTRACT FROM AUTHOR]

Persistent exposure to solar ultraviolet radiation (UVR) causes continuous damages to skin, including progressive impairment of epidermal stem cells (ESCs) capacities. Ghrelin is the only known endogenous orexigenic hormone, which has displayed its various pharmacological functions. In the current study, we found that the specific receptor of ghrelin, growth hormone secretagogue receptor (GHS-R), is expressed in ESCs. Interestingly, GHS-R expression is significantly upregulated in response to ultraviolet B (UVB) radiation. We also found that ghrelin treatment prevented UVB radiation-induced reduction in cell viability and the release of lactate dehydrogenase (LDH). Additionally, ghrelin reduced UVB radiation-induced generation of reactive oxygen species (ROS) and restored the intracellular level of reduced glutathione (GSH). UVB radiation significantly suppressed the expressions of integrin β1 and Krt19, the two major ESC markers, which were restored by ghrelin. Notably, knockdown of GHS-R abolished the effects of ghrelin on the expressions of integrin β1 and Krt19, suggesting the involvement of GHS-R. Also, we found that ghrelin treatment inhibited UVB radiation- induced reduction of Wnt1, Wnt3a, Myc, and cyclin D1 at both the mRNA levels and the protein levels. Taken together, our findings identify a novel function of ghrelin on maintaining the capacities of ESCs against UVB radiation. [ABSTRACT FROM AUTHOR]

The total phenolic content (TP) and antioxidant activity of the ethanolic extract and fractions that were obtained from the leaves of Nectandra hihua were assessed using different methods. The ethanolic extract (EE) and ethyl acetate fraction (EAF) had the best antioxidant capacity, which was comparable to butylated hydroxytoluene and quercetin (ABTS + 2.55 ± 0.06, 3.54 ± 0.03 mmol TE/g; DPPH IC 50 10.27 ± 0.05, 9.88 ± 0.02 μg/mL; FRAP 2.17 ± 0.08, 2.38 ± 0.04 mmol TE/g; ORAC 5.16 ± 0.08, 5.35 ± 0.07 mmol TE/g; TP 568.05 ± 18.15, 397.20 ± 17.88 mg GAE/g, respectively). The cytoprotective effect, reactive oxygen species (ROS) and lipid peroxidation inhibitions on L929 fibroblasts irradiated with UVB (600 mJ/cm 2 ) in pre- and post-treatments with EE and EAF were determined. These plant materials demonstrated high ROS scavenging activity and lipid peroxidation inhibition on L929 fibroblasts in both treatments, especially with pre-treatment (EE 38.47 ± 1.95% and EAF 40.20 ± 4.5% inhibition of ROS production, and EE 39.03 ± 3.33% and EAF 41.67 ± 7.6% of lipid peroxidation inhibition), indicating the best cytoprotection with pre-treatment (13.52 ± 1.66% and 13.34 ± 2.61% increases in cell viability). The antioxidant flavonoids quercitrin, avicularin, juglalin, afzelin and astragalin were isolated from EAF. The results obtained indicate that EE and EAF present photodamage attenuating potential against UVB-induced oxidative stress and can be useful as a starting point for developing dermatological products to prevent oxidative skin damage. [ABSTRACT FROM AUTHOR]

Background: Juglans regia L. has a history of traditional medicinal use for the treatment of various maladies and have been documented with significant antioxidant and antiinflammatory properties. Although all parts of the plant are medicinally important, but male the flower of the plant has not been yet investigated against the photo-damage.Purpose: The present study, we sought to determine the photoprotective effect of the male flower of J. regia L. against ultraviolet-B radiation-induced inflammatory responses in human skin cells.Methods: The profile of pharmacological active compounds present in the male flower of J. regia was analyzed by GC-MS. Then, the antioxidant property of methanolic extract of J. regia (MEJR) was analyzed by in vitro free radical scavenging assays. Further, we analyzed the sun protection factor of this extract by spectrophotometry. Moreover, we investigated the photoprotective effect of MEJR against UVB induced inflammatory signaling in human epidermal cells. Human skin epidermal keratinocytes (HaCaT) were pretreated with the MEJR (80 µg/ml), 30 min prior to UVB-irradiation at a dose of 20 mJ/cm2 and were investigated for lipid peroxidation, enzymatic antioxidants activity, apoptosis and inflammatory markers expression level.Results: The GC-MS results showed the presence of good amount of pharmacologically active compounds in the MEJR. We observed that the MEJR possess significant free radical scavenging activity and it was comparable with standard antioxidants. Further, the MEJR exhibits 8.8 sun-protection-factor (SPF) value. Pretreatment with MEJR, 30 min prior to UVB-irradiation, prevented ROS generation, lipid peroxidation and restored the activity of antioxidant status in HaCaT cells. Moreover, MEJR pretreatment significantly prevented UVB activated inflammatory markers like TNF-α, IL-1, IL-6, NF-κB, COX-2 in HaCaT.Conclusion: The present findings suggest that MEJR exhibit photoprotective effects and hence it may be useful for the treatment of inflammation related responses. The pharmacological mechanism of MEJR partly associated with its UV absorbance, modulation of inflammatory signaling as well as due to its free radical scavenging capability. [ABSTRACT FROM AUTHOR]

This study analyzed fruit stem extract (MGFE) from Muscat Bailey A grape ( Vitis labrusca  ×  Vitis vinifera ) for their ameliorative effects on Ultraviolet B (UVB)-induced skin damage in Balb/c mice. Well established in vivo assays were used to determine the biological effects of MGFE upon UVB irradiation of BALB/c mice. The results showed that treatment with MGFE recovered glutathione depletion, prevented lipid peroxidation of tissues and decreased the expression of DNA repair enzyme oxo guanine glycosylase-1. MGFE recovered the skin conditions in UVB-irradiated Balb/c mice. Moreover, MGFE inhibited dermal infiltration of inflammatory cells and reduced serum tumor necrosis factor alpha and interleukin-6 levels. Finally, MGFE treatment inhibited UV B -induced melanin formation and collagen fiber destruction through the inhibition of matrix metalloproteinase-1 expression. Through high-performance liquid chromatography analysis, catechin, epicatechin, and trans -resveratrol were found to be among the main active compounds present in MGFE. Taken together, these results indicated that MGFE has potentials as topical therapeutic materials against skin damage by inhibiting oxidative stress and inflammatory. [ABSTRACT FROM AUTHOR]

Natural molecules from different origins exhibit high therapeutic potential. Among them, molecules from marine algae are of particular interest. In the present study, we investigated the preventive effect of a protein extract (PE) of Ulva rigida against UVB-induced cellular damages. We demonstrated that a treatment of cortical astrocytes with 50 μg of PE induced a strong glioprotective effect and suppressed harmful effects of UVB radiations, increasing in particular cellular viability. In additional assays, this extract promoted the activity of catalase and superoxide dismutase and inhibited the production of stress markers, such as H 2 O 2 or lipid peroxidation. As expected, proteolytic digestion or heating treatment of algal extract inhibited this preventive effect, arguing for the predominant role of the protein fraction. Thereafter, proteomic investigations allowed to identify several proteins from the extract, among which calmodulin revealed to represent an important contributor to the observed protective activities. [ABSTRACT FROM AUTHOR]

Due to continuous exposure to ultraviolet B(UVB) radiation, eye lenses are constantly subjected to oxidative stress that induces lens epithelial cell (LEC) apoptosis, which has been associated with the inactivation of Sirtuin1 (SIRT1). It is well-established that NFE2L2 has a major protective effect on UVB-induced oxidative stress and damage. However, whether UVB radiation affects oxidative/antioxidative imbalance and damages LECs by inactivating the protective NFE2L2-mediated antioxidative stress pathway through inhibition of SIRT1 is unknown. In our research, we established in vivo and in vitro UVB exposure models in Sprague Dawley rats and SRA01/04 cells, respectively, to investigate the effect of UVB radiation on the NFE2L2/ KEAP1 pathway and the role of SIRT1 in this process. The in vivo findings revealed that UVB radiation exposure decreased Sirt1 and Nfe2l2 levels, upregulated Keap1 expression, led to an oxidative/antioxidative imbalance and increased LEC apoptosis in the eye lens. Sirt1 downregulated Keap1 expression levels, but activated Nfe2l2 and its downstream target proteins. The in vitro findings showed that UVB inhibited the deacetylation of SIRT1 target proteins and increased the acetylation levels of KEAP1 and NFE2L2. We also found that UVB radiation exposure led to a significant decrease in both co-localization levels and protein interaction between SIRT1 and KEAP1. In addition, the inhibition of SIRT1 increased KEAP1 levels, inhibited the activity of NFE2L2 and decreased co- localization levels and protein interactions between NFE2L2 and KEAP1. These results suggested that UVB radiation decreased SIRT1 levels and inhibited the KEAP1/NFE2L2 pathway, thereby reducing its antioxidant effect, which might be an important mechanism of UVB-induced cataract. [Display omitted] • UVB caused cataracts through oxidative stress and apoptosis. • UVB induced a reduction in Sirt1 concentration both in vivo and in vitro. • UVB caused oxidative stress in lens by affecting the KEAP1/NFE2L2 pathway. • UVB regulated the expression of KEAP1/NFE2L2 signaling pathway by inhibiting Sirt1. [ABSTRACT FROM AUTHOR]

Multifaceted changes in marine environments as a result of anthropogenic activities are likely to have a compounding impact on the physiology of marine phytoplankton. Most studies on the combined effects of rising p CO 2 , sea surface temperature, and UVB radiation on marine phytoplankton were only conducted in the short-term, which does not allow to test the adaptive capacity of phytoplankton and associated potential trade-offs. Here, we investigated populations of the diatom Phaeodactylum tricornutum that were long-term (∼3.5 years, ∼3000 generations) adapted to elevated CO 2 and/or elevated temperatures, and their physiological responses to short-term (∼2 weeks) exposure of two levels of ultraviolet-B (UVB) radiation. Our results showed that while elevated UVB radiation showed predominantly negative effects on the physiological performance of P. tricornutum regardless of adaptation regimes. Elevated temperature alleviated these effects on most of the measured physiological parameters (e.g., photosynthesis). We also found that elevated CO 2 can modulate these antagonistic interactions, and conclude that long-term adaptation to sea surface warming and rising CO 2 may alter this diatom's sensitivity to elevated UVB radiation in the environment. Our study provides new insights into marine phytoplankton's long-term responses to the interplay of multiple environmental changes driven by climate change. • Elevated UVB showed predominantly negative effects on P. tricornutum. • Elevated temperature alleviated these negative effects. • Elevated CO 2 modulated these antagonistic interactions between temperature and UVB. [ABSTRACT FROM AUTHOR]

Skin aging is a complex process that is strongly affected by UV radiation, which stimulates the production of reactive oxygen species (ROS) in the epidermis and dermis and subsequently causes skin damage. Among the major consequences are increased collagen degradation and reduced collagen synthesis. Previous reports have demonstrated the beneficial effects of polyphenols for healthy skin. Passiflora tarminiana Coppens & V.E. Barney, a species of the Passifloraceae family, is widely distributed in South America and is rich in flavonoids. We show that UVB radiation increases metalloproteinase 1 (MMP-1) and reduces procollagen production in human dermal fibroblast (HDF) cells in a dose- and time-dependent manner. We examined the antioxidant and antiaging effects of the extract and fractions of P. tarminiana fruits. The fractions showed high polyphenol content (620 mg EAG/g) and antioxidant activity, as measured by ORAC (4097 μmol ET/g) and ABTS (2992 μmol ET/g) assays. The aqueous fraction drastically inhibited the collagenase enzyme (IC 50 0.43 μg/mL). The extract and fractions presented photoprotective effects by reducing UVB-induced MMP-1 production, increasing UVB-inhibited procollagen production, and decreasing ROS production after UVB irradiation in HDF. Finally, the polyphenol contents of the extracts and fractions from P. tarminiana were analyzed by HPLC-DAD-ESI-MS n , and procyanidins and glycosylated flavonoids were identified. [ABSTRACT FROM AUTHOR]

Lippia graveolens HBK (Mexican oregano) is a species that is regularly used as a condiment in Mexican cuisine. In traditional medicine, it is used for the treatment of respiratory and digestive illnesses, headaches, rheumatism and inflammation-related disorders. The main chemical components reported in this species include the following: terpenoids, iridoids and flavonoids. The aim of this study was to determine the potential photochemopreventive effect of the methanolic extract of Lippia graveolens (MELG) against ultraviolet B (UVB)-induced skin cancer in SKH-1 mice. The phenolic content, radical scavenger activity, penetration and genotoxicity of the MELG were also evaluated. The MELG exhibited scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, superoxide and hydroxyl radicals, and it did not exhibit genotoxic activity in the micronucleus test. In addition, the MELG absorbed UVB (280 nm) electromagnetic radiation. The main components detected in the plant extract were naringenin and galangin, and pinocembrin was also isolated and identified through spectroscopic analysis. The MELG demonstrated a photoprotective effect against UVB-induced cell death in Escherichia coli . In chronic challenge experiments, the MELG protected against UVB-induced skin cancer in SKH-1 mice. The MELG penetrated the skin of mice. Topical administration of the MELG protected against chronic UVB-induced damage in mouse SKH-1 skin. Our results suggest that the MELG has photochemopreventive activity and may potentially prevent photo-tumorigenesis. [ABSTRACT FROM AUTHOR]

The usage of active compounds of dietary phytochemicals in prevention of UV-induced skin diseases is increasingly gaining attention in the development of skin care products. The purpose of this study was to measure the influence of delphinidin (as a botanical agent) on the cell mechanical properties evaluated by the atomic force microscopy (AFM) technique in the immortalized human keratinocyte cell line (HaCaT) exposed to UVB radiation. The cells were treated with various doses of UVB radiation with and without pre and post-treatment with selected concentrations of delphinidin. The measurements of the elastic properties revealed that the exposure of HaCaT cells to high dose of the UVB radiation (100 mJ/cm 2 ) caused a decrease in the cell elastic modulus. It was accompanied by the decrease of metabolic activity, rearrangement of actin cytoskeleton and disappearance of the cell repair marker 53BP1. Both pre-treatment and post-treatment with delphinidin at non-cytotoxic concentrations (5 or 10 μM), restored the elastic modulus of irradiated keratinocytes. A direct AFM analysis showed that the UVB-mediated decrease of the cell stiffness was restored more effectively when cells were treated with delphinidin after the UVB irradiation. The results demonstrate the regenerative effect of delphinidin on the mechanical properties of cells exposed to UVB radiation (100 mJ/cm 2 ), which may be due to antioxidant and inhibitory effect on matrix metalloproteinases activation. [ABSTRACT FROM AUTHOR]

This study was conducted to explore the role of UVB on benzanthrone (BA)-induced skin inflammation and its mechanism/s. SKH-1 hairless mice were topically exposed with BA (25 and 50 mg/kg b.wt) either alone or along with UVB (50 mJ/cm 2 ) for 24 h and estimation of ROS, histopathological analysis, myeloperoxidase (MPO) activity, mast cell staining, immunohistochemistry for COX-2 and iNOS as well as western blotting for MAPKs, p-NF-κB, c-jun, c-fos COX-2 and iNOS were carried out. Enhanced ROS generation, increased epidermal thickness, mast cell number, MPO activity, enhanced expression of COX-2 and iNOS, MAPKs, c-jun, c-fos, NF-κB were found in BA either alone or when followed by UVB treatment, compared to the control groups. Expression of COX-2, iNOS and phosphorylation of ERK1/2 were found to be more enhanced in BA and UVB- exposed group compared to BA and UVB only group, while phosphorylation of JNK1/2, p38, NF-κB and expression of c-jun and c-fos were comparable with BA and UVB only groups. In summary, we suggest that UVB exposure enhanced BA-induced SKH-1 skin inflammation possibly via oxidative stress-mediated activation of MAPKs-NF-κB/AP-1 signalling, which subsequently increased the expression of COX-2 and iNOS and led to inflammation in SKH-1 mouse skin. [ABSTRACT FROM AUTHOR]

UV-induced reactive oxygen species (ROS) have been implicated in photocarcinogenesis and skin aging. This is because UV-induced ROS can induce DNA damage that, if unrepaired, can lead to carcinogenesis. Sunscreens contain UV attenuators, such as organic chemical and/or physical UV filters, which can prevent all forms of damage from UV irradiation. In recent years, the effective broad-spectrum UV attenuation properties of ZnO-nanoparticles (ZnO-NPs) have made them attractive as active components in sunscreens and other personal care products. As the use of ZnO-NPs in sunscreens is on the rise, so is public concern about their safety, particularly with exposure to sunlight. Therefore, in the present study, using various experimental approaches, we investigated the possible toxic effects resulting from exposure to UVB and ZnO-NPs in primary mouse keratinocytes (PMKs) as well as in the skin of SKH-1 hairless mice. The findings of the present study demonstrated that co-exposure to UVB and ZnO-NPs: (1) translocated the ZnO-NPs into the nucleus of PMKs; (2) caused enhanced generation of ROS; (3) induced more severe DNA damage as evident by alkaline comet assay and immunocytochemistry for γ-H2AX and 8-hydroxy-2′-deoxyguanosine (8-OHdG); and (4) subsequently caused much more pronounced cell death in PMKs. Further, to elucidate the physiological relevance of these in vitro findings, SKH-1 hairless mice were topically treated with ZnO-NPs and after 30 min irradiated with UVB (50 mJ/cm 2 ). Interestingly, we found that co-exposure of ZnO-NPs and UVB caused increased oxidative DNA damage and cell death, indicated by immunostaining for 8-OHdG and TUNEL assay in sections of exposed mouse skin. Thus, collectively, our findings suggest that UVB exposure increases ZnO-NPs-mediated oxidative stress and oxidative damage, thereby enhancing ZnO-NPs-induced cell death. [ABSTRACT FROM AUTHOR]

Ultraviolet B (UVB) irradiation alters multiple molecular pathways in the skin, thereby inducing skin damage. Human dermal fibroblasts (HDFa) were subjected to single UVB-irradiation (18 mJ/cm 2 ) resulting in reactive oxygen species (ROS) generation, oxidative DNA damage and upregulation of nuclear factor kappa B (NF-κB) expression. Further, it has been observed that there was a significant cytokine production (TNF-α and IL-6) in UVB irradiated HDFa cells. Our results show that 7-hydroxycoumarin (7-OHC) prevents UVB-induced activation of NF-κB thereby subsequently preventing the overexpression of TNF-α and IL-6 in HDFa cells. Further, 7-OHC prevents UVB-induced activation of cyclooxygenase-2 (COX-2) expression, an inflammatory mediator in skin cells. Moreover, 7-OHC inhibited mRNA expression pattern of matrix metalloproteinases (MMP-1 and MMP-9) in UVB irradiated skin cells. Furthermore, 7-OHC restored antioxidant status, thereby scavenging the excessively generated ROS; consequently preventing the oxidative DNA damage. It has also been noticed that 7-OHC prevents UVB mediated DNA damage through activation of DNA repair enzymes such as XRCC1 and HOGG1. In this study, we treated HDFa cells with 7-OHC before and after UVB irradiation and we found that pretreatment showed better results when compared to posttreatment. Further, 7-OHC showed 9.8416 sun protection factor (SPF) value and it absorbs photons in the UVB wavelength rage. Thus, it has been concluded that sunscreen property, free radical scavenging potential and prevention of NF-κB activation play a role for photoprotective property of 7-OHC. [ABSTRACT FROM AUTHOR]

α-Tocopherol (Toc) is known to degrade to the tocopheroxyl radicals (Toc ) by exposure to UV light irradiation. In the present study, the stability of Toc ester derivatives exposed to UV light was investigated and compared with Toc in organic solution and in phospholipid vesicles. To follow the depletion of Toc and its esters the absorbance and fluorescence methods were applied whereas degradation products were detected using LC–MS method. The irradiation with UVB light of air-equilibrated solutions of di-α-Tocopheryl malonate (DTMO), α-Tocopheryl malonate (TMO) and α-Tocopheryl succinate (TS) strongly modifies their absorption and fluorescence spectra. Upon UVB irradiation, absorption band at 279/285 nm becomes less pronounced indicating the photodegradation of esters. During irradiation, the fluorescence maximum of esters at 305 nm shifts to 326 nm, a maximum characteristic for Toc. Photorecovery of Toc from its esters derivatives was finally confirmed by LC–MS method. Among studied esters, only α-tocopheryl nicotinate (TN) did not undergo depletion and appeared resistant to UVB radiation. Kinetic studies indicated that photoinduced transformation occurs through the first order consecutive reaction chain mechanism. The photodissociation of Toc esters in the liposomes occurred with one order of magnitude slower than in organic solvents. Using MS/MS method it was found that final stable product of irradiation was α-tocopheryl quinone (TQ), an animal and plant metabolite of Toc. [ABSTRACT FROM AUTHOR]

Toxic effects of petroleum to marine zooplankton have been generally investigated using dissolved petroleum hydrocarbons and in the absence of sunlight. In this study, we determined the influence of natural ultraviolet B (UVB) radiation on the lethal and sublethal toxicity of dispersed crude oil to naupliar stages of the planktonic copepods Acartia tonsa , Temora turbinata and Pseudodiaptomus pelagicus . Low concentrations of dispersed crude oil (1 μL L −1 ) caused a significant reduction in survival, growth and swimming activity of copepod nauplii after 48 h of exposure. UVB radiation increased toxicity of dispersed crude oil by 1.3–3.8 times, depending on the experiment and measured variables. Ingestion of crude oil droplets may increase photoenhanced toxicity of crude oil to copepod nauplii by enhancing photosensitization. Photoenhanced sublethal toxicity was significantly higher when T. turbinata nauplii were exposed to dispersant-treated oil than crude oil alone, suggesting that chemical dispersion of crude oil may promote photoenhanced toxicity to marine zooplankton. Our results demonstrate that acute exposure to concentrations of dispersed crude oil and dispersant (Corexit 9500) commonly found in the sea after oil spills are highly toxic to copepod nauplii and that natural levels of UVB radiation substantially increase the toxicity of crude oil to these planktonic organisms. Overall, this study emphasizes the importance of considering sunlight in petroleum toxicological studies and models to better estimate the impact of crude oil spills on marine zooplankton. [ABSTRACT FROM AUTHOR]

Combined effects of temperature, ultraviolet-B radiation and exogenous plant hormones on plant growth and development have received little attention. The objectives of this study were to determine morphological and physiological responses of pea ( Pisum sativum L. cv. 237, Mr. Big) to two temperature regimes (24/20 °C and 28/24 °C; 16 h day/8 h night), two UVB levels (0 and 5 kJ m −2 d −1 ), and two salicylic acid treatments (0 or 100 μl of 1 mM solution every other day). We germinated pea seeds under 24/20 °C, kept the seedlings under this condition for one week and then grew them under experimental conditions for three weeks. The measured parameters included growth and development, dry mass accumulation, gas exchange, chlorophyll fluorescence, chlorophyll content, epicuticular wax, and flavonoids. Higher temperatures reduced growth and biomass accumulation, and increased transpiration and stomatal conductance, leading to an overall decrease in water use efficiency (WUE). Regardless of UVB levels or salicylic acid application, higher temperatures decreased maximum quantum yield of PSII and non-photochemical quenching, but increased photochemical quenching and chlorophyll content. UVB radiation decreased overall growth and biomass accumulation as well as net CO 2 assimilation and WUE. Irrespective of temperature, UVB increased protective compounds (epicuticular wax and flavonoids), but decreased chlorophyll content. At both temperatures and UVB levels, exogenous salicylic acid significantly increased all aspects of plant growth and biomass accumulation. Also, salicylic acid significantly increased net CO 2 assimilation and marginally increased chlorophyll content, but had no effect on chlorophyll fluorescence or protective compounds. Several significant relationships were found between the above-mentioned parameters. Effects of temperature and UVB radiation were additive for stem height, leaf area, and growth rate. Plants grown under UVB5 with salicylic acid application had the most leaves, whereas plants grown under UVB5 without salicylic acid had the least. Similarly, plants grown under UVB0 with salicylic acid application had the largest leaves, whereas plants grown under UVB5 without salicylic acid had the smallest ones. This study revealed that higher temperatures and UVB radiation exert an adverse effect on pea plants, and some of the detrimental effects of these stress factors can be mitigated by exogenous salicylic acid. [ABSTRACT FROM AUTHOR]

Background Phenolic compounds, the biggest group of natural antioxidants, have attracted much attention due to their known and wide-ranging biological activities, as well as to their health effects. In particular, regardless their antioxidant activity, they play a key role in the control of several inflammation-associated processes as well as in improving antioxidant defense system. In an our previous work we have demonstrated the ability of Hydroxytyrosol, an ortho-diphenolic compound, essential component of oleuropein, in preventing apoptotic cell death induced by UVB radiation in HaCaT cell lines in vitro . In olive oil, besides Hydroxytyrosol, there are appreciable amounts of Tyrosol and its secoiridoid derivatives. Objective It has been well established that Tyrosol has a significantly lower antioxidant activity than Hydroxytyrosol, but despite this, recent studies suggest that Tyrosol exerts a powerful protective effect against oxidative injuries in cell systems and that it is able to improve the intracellular antioxidant defenses. Materials and methods Here, Tyrosol effect has been evaluated in HaCaT cells exposed to UVB radiation by means of morphological and molecular analyses. Results Our study revealed the polyphenol ability in reducing apoptotic markers and in protecting HaCaT cells from damage. Conclusion These findings suggest an important role of Tyrosol in protecting cells from apoptotic cell death and encourage the use of this phytochemical as biological ingredient in topical preparations as possible tool to prevent skin damage. [ABSTRACT FROM AUTHOR]

Evolutionary explanations for geography's influence on complex cognitive ability (CCA) imply virtually immutable components of between-nation IQ differences. Their weight vis-à-vis the weight of situational components was evaluated through an analysis of a 194-country data set. Additive effects of absolute latitude (AL) and longitudinal distance from Homo sapiens ' cradle (LDC) explain Northeastern Asian higher, Sub-Saharan African lower CCAs. AL exerts cognitive influence directly and through socioeconomic development and evolutionary genetics whereas LDC does through evolutionary genetics; however, this occurs differently in Africa-Near East-Europe and elsewhere. The findings are understood assuming supremacy of contemporary UV B radiation → hormonal and climatic → socioeconomic mediators of the AL–CCA linkage whose effects are moderated by heterogeneous genetic and cultural adaptations to radiation and climate. Geography's cognitive effects are dynamic and public-policy actions may modify them. [ABSTRACT FROM AUTHOR]

Background: Little is known about how the genetic variation in vitamin D modulating genes influences ultraviolet (UV)B--induced 25-hydroxyvitamin D [25(OH)D] concentrations. In the Food with vitamin D (VitmaD) study, we showed that common genetic variants rs10741657 and rs10766197 in 25-hydroxylase (CYP2R1) and rs842999 and rs4588 in vitamin D binding protein (GC) predict 25(OH)D concentrations at late summer and after 6-mo consumption of cholecalciferol (vitamin D3)-fortified bread and milk. Objectives: In the current study, called the Vitamin D in genes (VitDgen) study, we analyzed associations between the increase in 25(OH)D concentrations after a given dose of artificial UVB irradiation and 25 single nucleotide polymorphisms located in or near genes involved in vitamin D synthesis, transport, activation, or degradation as previously described for the VitmaD study. Second, we aimed to determine whether the genetic variations in CYP2R1 and GC have similar effects on 25(OH)D concentrations after artificial UVB irradiation and supplementation by vitamin D3-fortified bread and milk. Design: The VitDgen study includes 92 healthy Danes who received 4 whole-body UVB treatments with a total dose of 6 or 7.5 standard erythema doses during a 10-d period in winter. The VitmaD study included 201 healthy Danish families who were given vitamin D3-fortified bread and milk or placebo for 6 mo during the winter. Results: After UVB treatments, rs10741657 in CYP2R1 and rs4588 in GC predicted UVB-induced 25(OH)D concentrations as previously shown in the VitmaD study. Compared with noncarriers, carriers of 4 risk alleles of rs10741657 and rs4588 had lowest concentrations and smallest increases in 25(OH)D concentrations after 4 UVB treatments and largest decreases in 25(OH)D concentrations after 6-mo consumption of vitamin D3-fortified bread and milk. Conclusion: Common genetic variants in the CYP2R1 and GC genes modify 25(OH)D concentrations in the same manner after artificial UVB-induced vitamin D and consumption of vitamin D3-fortified bread and milk. The VitDgen study was registered at clinicaltrials.gov as NCT01741233. The VitmaD study was registered at clinicaltrials.gov as NCT01184716. [ABSTRACT FROM AUTHOR]

Tropical animals are regularly exposed to solar UV radiation. The generation and accumulation of free radicals as a result of UVB incidence causes tissue damage. In the present study we report that the irradiation of Funambulus pennanti by 1.5 J/cm 2 of UVB caused significant oxidative damage to the spleen. The systemic immunity suffered collateral damage as depicted by results of total leukocyte count (TLC) while an increase in the thiobarbituric acid reactive substances (TBARS) and decline in the activities of enzymes superoxide dismutase (SOD), Glutathione peroxidase (GSH-Px) and Catalase (CAT) denoted oxidative tissue damage. Melatonin the indole-amine with known antioxidative properties when administered subcutaneously (s.c 100 μg/100 gm body weight), before the UVB irradiation recovered the damages caused by UVB radiation in the spleen. The action of melatonin was direct and might have involved its membrane receptor (MT1) as well as nuclear receptor (RORα) indicating the fact that the mode of action of melatonin in ameliorating UVB radiation induced free radical load may be receptor mediated. Our study hence reports for the first time that UVB radiation incurred oxidative damage to the spleen and suppressed the normal tissue functions. This UVB mitigated oxidative stress was recovered by the free radical scavenging and anti-apoptotic functions of melatonin when administered prior to UVB irradiation. [ABSTRACT FROM AUTHOR]

Nanoparticulate Ca3(PO4)2:Gd3+,Pr3+ phosphor powders were synthesized by microwave-assisted methodology in an aqueous medium. The X-ray diffraction patterns of the nanopowders confirmed the successful crystallization of Ca3(PO4)2 that are consistent with the standard rhombohedral phase of Ca3(PO4)2. The average crystallite size calculated using William-Hall equation was 99 nm. The high resolution field emission electron microscopy data suggest that the powder consisted of an agglomeration of faceted hexagonal particles. Upon excitation with ultra violet (UV) radiation at 274 nm the phosphor exhibited a narrowband emission peak at a wavelength of 313 nm corresponding to the 6P7/2→8S7/2 transition of the Gd3+ ion. Upon co-doping with Pr3+ a broad excitation peak at 222 nm was observed, which was assigned to the 4f-5d transition of the Pr3+ ion. The peak intensity of the UVB emission at 313 nm was shown to improve considerably when excited at 222 nm, suggesting that Pr3+ harvested primary excitation energy and transferred it non-radiatively to Gd3+. [ABSTRACT FROM AUTHOR]

Abstract: The vulnerability and acclimation to increased UVB radiation in three macroalgae of different morpho-functional groups collected in the Mediterranean coastal waters were evaluated. The algae were submitted for 7 days to increased (PAB+) and decreased (PAB−) UVB radiation. The thickness and morphology influenced the response to increased UVB radiation, being Cystoseira tamariscifolia the less vulnerable algae followed by Ellisolandia elongata. The highest resistance to increased UVB radiation in C. tamariscifolia was related to the accumulation of polyphenols and high antioxidant activity, whereas E. elongata was due to its high reflectance. Finally, Ulva rigida suffered the highest photoinhibition under PAB+ culture. The latest species presented 10 times lower polyphenol content and antioxidant activity than C. tamariscifolia. The three species showed different acclimation patterns to the changes of UVB radiation related to the morphology, photosynthetic activity, accumulation of photoprotectors and antioxidant activities. The ecological implications of the UVB variations on macroalgae are discussed. [Copyright &y& Elsevier]

Highlights: [•] The influence of urea in the crystallinity of Ca3(PO4)2. [•] The influence of Gd3+ and Pr3+ doping on the particle morphology. [•] Specific elemental topography of each individual ions distributed across the surface. [•] The importance of using specific concentration of Pr3+ for efficient energy transfer. [ABSTRACT FROM AUTHOR]

Abstract: An outdoor test facility is installed at the College of Technological Studies, Kuwait for continuous measurements of solar UVB radiation, solar global radiation, relative humidity in Kuwait for two years in the period from 1st June 2010 till 31st May 2012. It is found that the variation of diurnal UVB and global radiation with time of the day almost follows the same trend for all measured clear days. Regression analysis is adapted to establish a mathematical formula relating UVB radiation to both the global solar radiation and relative humidity. The statistical analysis of the present results revealed that there is strong relationship between UVB radiation and both global solar radiation and relative humidity, particularly in the region of moderate to low global solar radiation values. The value of UV (ultraviolet) index which is a measure of the UV radiation level at the Earth's surface is determined at different months through the day hours. The highest UV index values are achieved through the months May–August during the midday hours. However, the values of UV index never exceed the extreme value (i.e. ≥9) at any hour of the day throughout the whole period of study. [Copyright &y& Elsevier]

Abstract: Mid-Ultraviolet (UVB) has a significant influence on human health. In this study, human erythrocytes were exposed to UVB to investigate the effects of UVB radiation on erythrocytes membrane. And Micro-Raman spectroscopy was employed to detect the damage. Principal component analysis (PCA) was used to classify the control erythrocytes and the irradiated erythrocytes. Results showed that the erythrocytes membrane was damaged by Mid-Ultraviolet (UVB) radiation. The intensity of the Raman peaks at 1126cm−1 and 1082cm−1 were used to calculate the Longitudinal Order-Parameters in Chains (Strans ) which can present the liquidity and ionic permeability of erythrocyte membrane. After UVB radiation for 30min, both the liquidity and ionic permeability decreased. At the same time, the intensity of the peaks at 1302cm−1 (α-helix), 1254cm−1 (random coil), 1452cm−1 and 1430cm−1 (CH2/CH3 stretch) have also changed which indicated the membrane protein also been damaged by UVB. In the whole process of radiation, the more UVB radiation dose the more damage on the erythrocyte membrane. [Copyright &y& Elsevier]

The long-term effects of UVB exclusion and temperature on the methanol extractable (ME) phenolics (flavonoids, phenolic acids) and iridoids of Menyanthes trifoliata L. (Mt) leaves were studied in northern Finland (68°N) using wooden frames covered with filters for UVB exclusion (polyester filter), control (cellulose acetate filter) and ambient (no filter) conditions. Analysis of ambient plots showed no effect of the daily mean temperature (2σ = 1.58 °C) on the leaf ME compound content and composition, but minimum temperatures decreased the flavonol content. UVB exclusion did not affect the total ME compound content but significantly decreased the proportion of flavonols concomitantly with an increase in iridoids. Due to its high iridoid content, Mt appears as an interesting model plant for studying the iridoid biosynthesis and its regulation under stress conditions. [Copyright &y& Elsevier]

Abstract: The present study evaluated the potential of a w/o microemulsion as a topical carrier system for delivery of the antioxidant quercetin. Topical and transdermal delivery of quercetin were evaluated in vitro using porcine ear skin mounted on a Franz diffusion cell and in vivo on hairless-skin mice. Skin irritation by topical application of the microemulsion containing quercetin, and the protective effect of the formulation on UVB-induced decrease of endogenous reduced glutathione levels and increase of cutaneous proteinase secretion/activity were also investigated. The w/o microemulsion increased the penetration of quercetin into the stratum corneum and epidermis plus dermis at 3, 6, 9 and 12h post-application in vitro and in vivo at 6h post-application. No transdermal delivery of quercetin occurred. By evaluating established endpoints of skin irritation (erythema formation, epidermis thickening and infiltration of inflammatory cells), the study demonstrated that the daily application of the w/o microemulsion for up to 2 days did not cause skin irritation. W/o microemulsion containing quercetin significantly prevented the UVB irradiation-induced GSH depletion and secretion/activity of metalloproteinases. [Copyright &y& Elsevier]

Abstract: Combined effects of UVB radiation and CO2 concentration on plant reproductive parts have received little attention. We studied morphological and physiological responses of siliquas and seeds of canola (Brassica napus L. cv. 46A65) to UVB and CO2 under four controlled experimental conditions: UVB radiation (4.2kJm−2 d−1) with ambient level of CO2 (370μmolmol−1) (control); UVB radiation (4.2kJm−2 d−1) with elevated level of CO2 (740μmolmol−1); no UVB radiation (0kJm−2 d−1) with ambient level of CO2 (370μmolmol−1); and no UVB radiation (0kJm−2 d−1) with elevated level of CO2 (740μmolmol−1). UVB radiation affected the outer appearance of siliquas, such as colour, as well as their anatomical structures. At both CO2 levels, the UVB radiation of 4.2kJm−2 d−1 reduced the size of seeds, which had different surface patterns than those from no UVB radiation. At both CO2 levels, 4.2kJm−2 d−1 of UVB decreased net CO2 assimilation (A N) and water use efficiency (WUE), but had no effect on transpiration (E). Elevated CO2 increased A N and WUE, but decreased E, under both UVB conditions. At both CO2 levels, the UVB radiation of 4.2kJm−2 d−1 decreased chlorophyll fluorescence, total chlorophyll (Chl), Chl a and Chl b, but had no effect on the ratio of Chl a/b and the concentration of UV-screening pigments. Elevated CO2 increased total Chl and the concentration of UV-screening pigments under 4.2kJm−2 d−1 of UVB radiation. Neither UVB nor CO2 affected wax content of siliqua surface. Many significant relationships were found between the above-mentioned parameters. This study revealed that UVB radiation exerts an adverse effect on canola siliquas and seeds, and some of the detrimental effects of UVB on these reproductive parts can partially be mitigated by CO2. [Copyright &y& Elsevier]

Abstract: Recent predictions anticipate a solar ultraviolet-B increase of 5–10% over temperate latitudes within the next 15 years. As Mediterranean waters are clear, enabling deep UVB penetration, we used controlled experiments to test the effects of equivalent levels of UVB on trophic plankton interactions. We grew the diatom Skeletonema costatum in the laboratory under daily 4 h UVB exposure in doses of 10% higher than today in contrast to control cultures (no UVB). UVB-exposed algae showed modification in cell structure, volume increase and delay in cell division, eventually leading to lysis and cell death after five days of daily 4 h exposure. Both control and UVB-stressed S. costatum cultures were used as food for wild Calanus helgolandicus females collected in the NW Mediterranean. Those fed on control diatoms produced three times more eggs, healthier offspring with fewer lethal naupliar deformities than females fed on UVB-exposed diatoms. Our results provide the first experimental evidence of indirect UVB effects on reproductive output through trophic response in marine plankton. The sensitivity of the S. costatum strain is discussed as well as the reduced reproductive output of the female copepods. We suggest that the low egg numbers and high naupliar deformity ratios are possibly a consequence of UVB-induced deficiency of essential components in the UVB-stressed maternal diet. [Copyright &y& Elsevier]

Abstract: Several studies have shown that UV radiation on the skin results in the formation of reactive oxygen species (ROS) that interact with proteins, lipids and DNA, thus altering cellular functions. The epidermis is composed mainly of keratinocytes, rich in ROS detoxifying enzymes and in low-molecular-mass antioxidant molecules. However, the increased generation of ROS can overwhelm the natural defences against oxidative stress. Therefore treatment of the skin with products containing plant-derived antioxidant ingredients may be a useful strategy for the prevention of UV-mediated cutaneous damage. In the present study we have investigated the in vitro capability of a Jacquez grapes wine extract (containing a significant level of proanthocyanidins, together with lower amounts of anthocyanins and hydroxycinnamic acids; JW-E), to protect skin against UVB-induced oxidative damage by using a three-dimensional tissue culture model of human epidermis. The endpoints of our experiments were cell viability, release of interleukin-1α and prostaglandin E 2 (well-known mediators of cutaneous inflammatory processes), accumulation in the epidermis of malondialdehyde/4-hydroxynonenal and protein carbonyl groups (derived by the oxidative damage respectively of lipids and proteins) and tissue redox balance (expressed by the levels of reduced glutathione, oxidized glutathione, glutathione peroxidase and glutathione reductase). Taken together, our findings demonstrate that the JW-E is an efficient botanical mixture able to prevent skin oxidative damage induced by UV-B exposure and may thus be a potential promising candidate as a skin photoprotective agent. [Copyright &y& Elsevier]

Abstract: The p38 MAPK pathway controls critical premitochondrial events culminating in apoptosis of UVB-irradiated human keratinocytes, but the upstream mediators of this stress signal are not completely defined. This study shows that in human keratinocytes exposed to UVB the generation of reactive oxygen species (ROS) acts as a mediator of apoptosis signal regulating kinase-1 (Ask-1), a redox-sensitive mitogen-activated protein kinase kinase kinase (MAP3K) regulating p38 MAPK and JNK cascades. The NADPH oxidase antagonist diphenylene iodonium chloride and the EGFR inhibitor AG1487 prevent UVB-mediated ROS generation, the activation of the Ask-1-p38 MAPK stress response pathway, and apoptosis, evidencing the link existing between the early plasma membrane-generated ROS and the activation of a lethal cascade initiated by Ask-1. Consistent with this, Ask-1 overexpression considerably sensitizes keratinocytes to UVB-induced mitochondrial apoptosis. Although the JNK pathway is also stimulated after UVB, the killing effect of Ask-1 overexpression is reverted by p38 MAPK inhibition, suggesting that Ask-1 exerts its lethal effects mainly through the p38 MAPK pathway. Moreover, p38α−/− murine embryonic fibroblasts are protected from UVB-induced apoptosis even if JNK activation is fully preserved. These results argue for an important role of the UVB-generated ROS as mediators of the Ask-1-p38 MAPK pathway that, by culminating in apoptosis, restrains the propagation of potentially mutagenic keratinocytes. [Copyright &y& Elsevier]

Abstract: UV radiation-induced skin damages may result in pre-cancerous and cancerous skin lesions, and acceleration of skin aging. It involves an imbalance of the endogenous antioxidant system that leads to the increase of free radical levels and inflammation. Therefore, antioxidant supplementation might inhibit such imbalance. In this regard, quercetin is a promising drug, this plant derived lipophilic flavonoid presents the higher antioxidant activity among flavonoids and multiple antioxidant mechanisms. Thus, the present study investigated the possible beneficial effects of topical formulations containing quercetin to inhibit UVB irradiation-induced oxidative damages. Quercetin was administered on the dorsal skin of hairless mice using two formulations, formulation 1 (non-ionic emulsion with high lipid content) and formulation 2 (anionic emulsion with low lipid content). The UVB irradiation (0.31–3.69J/cm2) induced a dose-dependent increase in the myeloperoxidase (MPO) activity (4–2708%) and depletion of reduced glutathione (GSH) (22–68%) in the skin of hairless mice after 6h. These results demonstrated that the UVB doses are not excessive, and additionally, they are lower than the doses used in other similar studies. Proteinases secretion/activity, detected by the qualitative sodium dodecyl sulphate polyacrylamide gel electrophoresis substrate-embedded enzymography (zymography), was also enhanced in the same manner as MPO activity using the UVB dose of 1.23J/cm2. Formulations 1 and 2 inhibited the MPO activity increase (62% and 59%, respectively), GSH depletion (119% and 53%, respectively) and proteinases secretion/activity. To our knowledge, this is the first study to demonstrate the effectiveness of topical formulations containing quercetin to inhibit the UVB irradiation-induced skin damages. Thus, these data suggest the possible usefulness of topical formulations containing quercetin to prevent UVB radiation skin damages. [Copyright &y& Elsevier]

Abstract: Exposure to ultraviolet-B radiation (UVB) radiation affects plants in multiple ways, including effects on the photosynthetic apparatus. The carbon dioxide reduction reactions are affected as well as the light reactions, especially those of photosystem II. In the literature several UVB chromophores are suggested, including redox-active tyrosines, plastosemiquinones, and the manganese cluster of the water-splitting complex. We measured the damage by UVB radiation given together with a small component of photosynthetically active radiation (PAR) in a triazine-resistant biotype and a wild-type of Chenopodium album. The damage was estimated by chlorophyll fluorescence measurements and was larger in the resistant plants. We were able to show that the concentration of the semireduced primary quinone electron acceptor of photosystem II is higher in the resistant plants, under all radiation conditions tested. This finding and additional results support the hypothesis that plastosemiquinones are photosensitizers for UVB radiation; absorption of UVB light by these quinones initiates reactions leading to damage to photosystem II. [Copyright &y& Elsevier]

Abstract: TGF-β produced by keratinocytes in response to UVB (290–320 nm) is a potential mediator for effects of acute and chronic solar radiation on skin. This study was designed to determine whether reactive oxygen species (ROS) mediate UVB-induced TGF-β biosynthesis in keratinocytes and the subsequent activation of the latent TGF-β complex. UVB irradiation elevated both total (latent plus active) and active TGF-β in the keratinocyte supernatants, with a greater increase in the active form. UVB irradiation induced up to a 30% increase in ROS, and the ROS were detected up to 90 min after irradiation. NAC and Trolox, cytoplasmic ROS scavengers, abolished the UVB-induced TGF-β and intracellular ROS, suggesting that UVB-induced ROS are involved in TGF-β regulation. Inhibitors of NADPH oxidase activity, DPI and apocynin, decreased UVB-induced ROS. The increase in NADPH oxidase activity was mediated by EGFR activation. UVB-induced ROS also activated latent TGF-β complex by stimulating MMP-2 and -9 activities. In summary, physiological doses of UVB increase intracellular ROS, which upregulate TGF-β biosynthesis and activation of TGF-β through increased activity of MMPs. [Copyright &y& Elsevier]

To study the preconditioning effects of exposure to UVB on heat tolerance (44–48 °C), 10-day-old cucumber (Cucumis sativus L.) seedlings were irradiated for 6 days with a daily dose of either 3.4, 5.5 or 10.6 kJ m−2 of biologically effective UVB (UVBBE). Cellulose diacetate-filtered UVB lamps were used to supply UVB. These approximated low, ambient (medium) and twice-ambient (high) UVB doses, respectively, at 42°N latitude on a clear day during the summer solstice. A parallel group of control plants, held under polyester (PE)-filtered UVB lamps, received no UVB. UVB treatment increased the level of methanol-extractable UV-absorbing phenols in cotyledons and primary leaves. In a further HPLC analysis of acid-hydrolyzed leaf extract, eight peaks were separated. The two major peaks were co-chromatographed with authentic flavonoids, quercetin and kaempferol. The quercetin-like compound was preferentially enhanced in UVB-exposed plants. When the low and medium UVB-irradiated plants were later heat-stressed (46 °C, 1 h), survival improved by 112 and 82% and height growth increased by 35 and 40%, respectively, compared with controls that received no UVB. In contrast to low and ambient levels of UVB, which reduced membrane leakage, twice-ambient levels increased lipid peroxidation and electrolyte leakage. Although exposure to above-ambient levels of UVB was injurious, low and ambient doses of UVB promoted survival and growth of cucumber seedlings. Such a synergism between UVB and heat tolerance could be used to precondition seedlings grown in UVB-deficient greenhouses and may benefit plants under the predicted global warming scenario. [Copyright &y& Elsevier]

Mice defective in the mismatch repair (MMR) gene Msh2 manifest an enhanced predisposition to skin cancer associated with exposure to UVB radiation. This predisposition is further heightened if the mice are additionally defective for the nucleotide excision repair gene Xpc. To test the hypothesis that the predisposition of Msh2 mutant mice to skin cancer reflects a mutator phenotype associated with increased proliferation of skin cells following exposure to UV radiation, Msh2 mutant mice were exposed to the tumor promoter TPA. Such mice showed a robust proliferative response in the skin, but did not manifest evidence of dysplasia or neoplasia. We conclude that the predisposition of Msh2 mice to UVB radiation-induced skin cancer reflects an interaction between the processes of mismatch repair and some other excision repair mode, the exact nature of which remains to be established. [ABSTRACT FROM AUTHOR]

Ultraviolet-B radiation (UVB) causes a variety of biological effects which include the induction of apoptosis. UVB-induced apoptosis provides a well controlled scavenging mechanism protecting cells from malignant transformation. To induce programmed cell death, UVB uses a variety of cellular signaling pathways. In this context induction of nuclear DNA damage seems to be the predominant pathway, since experimental reduction of DNA damage was associated with a strong suppression of apoptosis. Additionally, UVB has been shown to target cytoplasmatically located or membrane bound components to induce signal transduction. UVB was found to directly activate cell surface death receptors, thereby triggering the apoptotic machinery. Furthermore, UVB-induced intracellular formation of reactive oxygen species (ROS) accompanied by mitochondrial dysfunction and cytochrome c release was demonstrated to be additionally involved in the apoptotic program. The following review will briefly discuss current aspects of the interplay between the different signaling pathways involved in UVB-induced apoptosis. [Copyright &y& Elsevier]

Herein it is proposed that sufficient exposure to sunlight (UVB) modulates host gene expression, offering protection against severe consequences of COVID-19. This could be in addition to sunlight (UVB)-mediated protection by directly inactivating the virus and limiting the viral load. It is suggested that inhibition of CCR2, DPP9, HSPA1L, IFNAR2, OAS1, and TYK2 may, in part, explain UVB-mediated protection against severe consequences of COVID-19. [Display omitted] [ABSTRACT FROM AUTHOR]

iTRAQ proteomic profiling was conducted to examine the proteomic responses of the Antarctic copepod Tigriopus kingsejongensis under ultraviolet B (UVB) exposure. Of the 5507 proteins identified, 3479 proteins were annotated and classified into 25 groups using clusters of orthologous genes analysis. After exposing the T. kingsejongensis to 12 kJ/m2 UVB radiation, 77 biological processes were modulated over different time periods (0, 6, 12, 24, and 48 h) compared with the control. A Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that UVB exposure in T. kingsejongensis downregulated ribosome and glyoxylate and dicarboxylate metabolism at all time points. Furthermore, antioxidant and chaperone proteins were highly downregulated in response to UVB exposure, causing protein damage and activating apoptotic processes in the 48 h UVB exposure group. These proteomic changes show the mechanisms that underlie the detrimental effects of UVB on the cellular defense systems of the Antarctic copepod T. kingsejongensis. [Display omitted] • iTRAQ proteomic profiling was conducted to examine the proteomic responses of the Antarctic copepod to UVB radiation. • Of the 5507 proteins identified, 3479 proteins were annotated and classified into 25 groups using COGs analysis. • UVB exposure in T. kingsejongensis downregulated ribosome and glyoxylate and dicarboxylate metabolism at all time points. • Antioxidant and chaperone proteins were mostly downregulated in response to UVB exposure. • The detrimental effects of UVB on the cellular defense systems of the Antarctic copepod T. kingsejongensis were demonstrated. [ABSTRACT FROM AUTHOR]

• UVB radiation exacerbate skin lesion of mice infected with L. mexicana. • UVB-radiation induces systemic IgG1 specific antibodies response and local immune suppression. • UVB-radiation induces an increase of IL-10 reactive cells in local skin lesion. • Solar overexpose may be a risk factor for human cutaneous leishmaniosis in endemic areas. Cutaneous leishmaniasis is the most common form of leishmaniasis in humans. The disease is caused by several species, such as Leishmania mexicana , a protozoa parasite. Several major risk factors are associated with this disease, including poverty, poor housing, inadequate domestic hygiene, malnutrition, mobility, and occupational exposure. Solar radiation (UVB) has not been considered a risk factor because there is no scientific evidence demonstrating a correlation with increased susceptibility to cutaneous leishmaniasis. In this study, the shaved skin of the back of C57BL/6 mice was irradiated with 24.2 mJ/cm2 of UVB. A delayed-type hypersensitivity (DTH) reaction was used to assess UV-induced immune suppression. Skin lesions were quantitated, and parasite burden and the presence of anti- Leishmania mexicana antibodies in serum and germinal centers in draining lymph nodes were determined. We found an increased in the lesion size and parasitic load in UVB-irradiated mice compared to the WT mice and B lymphocyte activation in draining lymph nodes and increased IgG1 production. Our results show an important role of UVB-induced suppression in cutaneous leishmaniasis through local production of IL-10 and systemic IgG1antibodies. This is the first study that demonstrates the effects of UVB radiation on cutaneous leishmaniasis by Leishmania mexicana. [ABSTRACT FROM AUTHOR]

Ultraviolet B (UVB) radiation in low but ecological-relevant doses acts as a regulator in the plant's secondary metabolism. This study investigates the effect of UVB radiation from light-emitting diodes (LEDs) [peak wavelength of (290 ± 2) nm] on the biosynthesis of health-promoting secondary plant metabolites (carotenoids, phenolic compounds, and glucosinolates) of green and red leafy vegetables of Lactuca sativa , Brassica campestris , and Brassica juncea followed by evaluation of potential adverse effects in a human liver cell model. UVB radiation led to a significant increase in individual secondary plant metabolites, especially of phenolic compounds and glucosinolates, e.g. alkenyl glucosinolate content. Kaempferol und quercetin glycoside concentrations were also significantly increased compared to untreated plants. The plant extracts from Lactuca sativa, Brassica campestris , and Brassica juncea were used to assess cytotoxicity (WST-1 assay and trypan blue staining), genotoxicity (Comet assay), and production of reactive oxygen species (EPR) using metabolically competent human-derived HepG2 liver cells. No adverse effects in terms of cytotoxicity, genotoxicity, or oxidative stress were detected in an extract concentration ranging from 3.125 to 100 μg ml−1. Notably, only at very high concentrations were marginal cytostatic effects observed in extracts from UVB-treated as well as untreated plants. In conclusion, the application of UVB radiation from LEDs changes structure-specific health-promoting secondary plant metabolites without damaging the plants. The treatment did not result in adverse effects at the human cell level. Based on these findings, UVB LEDs are a future alternative, promising light source to replace currently commonly used high-pressure sodium lamps in greenhouses. [ABSTRACT FROM AUTHOR]

[Display omitted] • Liquiritin specifically promotes the activation of Sirt3. • Liquiritin inhibits inflammation and collagen degradation. • Liquiritin reduces the level of pro-inflammatory cytokines in the skin lesions. • Liquiritin slow down UVB irradiation injury via the Sirt3/ROS/NF-κB pathway. Overexposure to ultraviolet B (UVB) rays can cause damage to the skin. Liquiritin has a variety of pharmacological effects, such as anti-inflammatory and antioxidant. In the present study, the effect of liquiritin on UVB irradiated rat skin was investigated. Results showed that UVB irradiation caused erythema and wrinkles on the skin surface, as well as thickening and loss of elasticity of the epidermis and a significant increase in the level of ROS in the skin tissue. At the same time, western blot detected an increase in nuclear factor kappa-B (NF-κB) and matrix metalloproteinases (MMPs) and Elisa also detected an increase in pro-inflammatory factors. Therefore, we hypothesized that UVB irradiation-induced damage is associated with inflammation. Interestingly, application of liquiritin to exposed skin of rats reduced the increase in ROS, pro-inflammatory factors, and MMPs caused by UVB irradiation and increased the levels of Sirtuin3 (SIRT3) and Collagen α1. In addition, after intraperitoneal injection of the SIRT3 inhibitor 3-TYP in rats, the protective effect of liquiritin against UVB damage was found to be diminished. These results suggested that promotion of SIRT3 with liquiritin inhibits UVB-induced production of pro-inflammatory mediators, possibly acting through the SIRT3/ROS/NF-κB pathway. In conclusion, this study suggests that liquiritin is an effective drug candidate for the prevention of UVB damage. [ABSTRACT FROM AUTHOR]