Human psychophysics and rodent spinal neurones exhibit peripheral and central mechanisms of inflammatory pain in the UVB and UVB heat rekindling models.

Science.gov (United States)

O'Neill, Jessica; Sikandar, Shafaq; McMahon, Stephen B; Dickenson, Anthony H

2015-09-01

Translational research is key to bridging the gaps between preclinical findings and the patients, and a translational model of inflammatory pain will ideally induce both peripheral and central sensitisation, more effectively mimicking clinical pathophysiology in some chronic inflammatory conditions. We conducted a parallel investigation of two models of inflammatory pain, using ultraviolet B (UVB) irradiation alone and UVB irradiation with heat rekindling. We used rodent electrophysiology and human quantitative sensory testing to characterise nociceptive processing in the peripheral and central nervous systems in both models. In both species, UVB irradiation produces peripheral sensitisation measured as augmented evoked activity of rat dorsal horn neurones and increased perceptual responses of human subjects to mechanical and thermal stimuli. In both species, UVB with heat rekindling produces central sensitisation. UVB irradiation alone and UVB with heat rekindling are translational models of inflammation that produce peripheral and central sensitisation, respectively. The predictive value of laboratory models for human pain processing is crucial for improving translational research. The discrepancy between peripheral and central mechanisms of pain is an important consideration for drug targets, and here we describe two models of inflammatory pain that involve ultraviolet B (UVB) irradiation, which can employ peripheral and central sensitisation to produce mechanical and thermal hyperalgesia in rats and humans. We use electrophysiology in rats to measure the mechanically- and thermally-evoked activity of rat spinal neurones and quantitative sensory testing to assess human psychophysical responses to mechanical and thermal stimulation in a model of UVB irradiation and in a model of UVB irradiation with heat rekindling. Our results demonstrate peripheral sensitisation in both species driven by UVB irradiation, with a clear mechanical and thermal hypersensitivity of

Physiological effects of short acute UVB treatments in Chenopodium quinoa Willd.

Science.gov (United States)

Huarancca Reyes, Thais; Scartazza, Andrea; Castagna, Antonella; Cosio, Eric G; Ranieri, Annamaria; Guglielminetti, Lorenzo

2018-01-10

Increased ultraviolet B (UVB) radiation due to global change can affect plant growth and metabolism. Here, we evaluated the capacity of quinoa to resist under short acute UVB irradiation. Quinoa was daily exposed for 30 or 60 min to 1.69 W m -2 UVB. The results showed that 30 min exposure in 9 d-course did not cause severe alterations on photosynthetic pigments and flavonoids, but a significant increase of antioxidant capacity was observed. Otherwise, 60 min UVB in 5 d-course reduced almost all these parameters except for an increase in the de-epoxidation of xanthophyll cycle pigments and led to the death of the plants. Further studies of gas exchange and fluorescence measurements showed that 30 min UVB dramatically decrease stomatal conductance, probably associated to reactive oxygen species (ROS) production. Inhibition of photosynthetic electron transport was also observed, which could be a response to reduce ROS. Otherwise, irreversible damage to the photosynthetic apparatus was found with 60 min UVB probably due to severe ROS overproduction that decompensates the redox balance inducing UVB non-specific signaling. Moreover, 60 min UVB compromised Rubisco carboxylase activity and photosynthetic electron transport. Overall, these data suggest that quinoa modulates different response mechanisms depending on the UVB irradiation dosage.

Effects and mechanism of UV-B radiation on rice growth

International Nuclear Information System (INIS)

Gao Xiaoxiao; Gao Zhaohua; Zu Yanqun

2009-01-01

The enhancement of UV-B radiation influences the growth of rice and physiology in different levels and this performances as changes in morphology destroyed photosynthetic system unstable anti-oxidation system changes of endogenous hormone content exacerbated rice diseases decreased biomass and developmental stage delay. Through the establishment of the response index we can evaluate the varietal differences in responses of the rice to UV-B radiation. Reasons for such varietal differences were differences in rice gene physiology and morphology developmental stage and environmental factors. The main mechanism in responses of the rice to UV-B radiation was induction of flavonoid compounds and accumulation of anthocyanins. Based on the analysis of the influence of enhanced UV-B radiation to rice and the varietal differences in responses to UV-B radiation and mechanism of rice the direction of the further research about the relationship between the rice and UV-B was put forward

UV-B and Mediterranean forest species: Direct effects and ecological consequences

International Nuclear Information System (INIS)

Paoletti, E.

2005-01-01

Experimental results from plants receiving elevated doses of UV-B radiation generally show that Mediterranean forest species are well protected against increases in UV-B radiation. Natural adaptations to water stress and excess light (elevated concentrations of UV-B screening compounds, leaf hairs, thick cuticle and epidermis), and UV-B responses (thickening of the cuticle, increase in carotenoids) may avoid or counter-balance UV-B radiation damage. This response confirms that Mediterranean forest vegetation is adapted to face oxidative stress factors, such as elevated tropospheric ozone concentrations, drought and high radiation, including UV-B. Nevertheless, in the long term, species-specific and season-specific differential responses in growth, physiology, phenology and reproductive behaviour may alter the interactions between species and lead to slow but important changes in ecosystem structure and function. - Mediterranean plant adaptations against water stress and excess light may also afford protection against UV-B

The effect of ultraviolet (UV)-B radiation on primary producers

International Nuclear Information System (INIS)

Germ, M.

2003-01-01

Ozone layer in stratosphere is thinning and consequently UV-B radiation on the Earth surface is increasing. Although there is a small portion of UV-B radiation in the solar radiation, it has strong influence on organisms. Targets of UV-B radiation and protective mechanisms in primary producers are described. In the framework of the international project we studied the effect of UV-B radiation on blue-greens, algae, mosses, lichens and vascular plants on the National Institute of Biology

Flavonoids are systemically induced by UV-B in Zea mays

International Nuclear Information System (INIS)

Tossi, V.E.; Lamattina, L.; Cassia, R.

2009-01-01

Flavonoid concentration is increased by UV-B irradiation, but it is unknown if this is a local or systemic response. Nitric oxide (NO) is a diffusible molecule involved in the UV-B response. NO regulates the expression of chalcone synthase (CHS), a key enzyme in the synthesis of flavonoids. The aim of this work was to determine if maize flavonoids are local or systemically induced by UV-B, and what is the participation of NO in this response. We have used maize seedlings where the second leaf was sprayed with H 2 O or cPTIO (a NO scavenger), and then completely covered (C), partially covered (P) or uncovered (U) before to be UV-B irradiated. The results show a 60% increase in the NO concentration of U, 42% in P and 35% in C respectively. Flavonoid concentration increased 90% in C, 70% in P and 40% in U. Flavonoid concentration was reduced when leaves were pretreated with cPTIO before the UV-B irradiation. RT-PCR shows that CHS was up-regulated by UV-B in U, P and C, but downregulated with cPTIO. We have analyzed the subcellular localization of flavonoid and NO in UV-B irradiated plants. Flavonoid localization was coincident with the NO presence in the irradiated surface of the leaves and flavonoids were detected in vesicles. These results indicate that flavonoids are systemically induced by UV-B in a NO-related mechanism. (authors)

Risks of increased UV-B radiation for humans

International Nuclear Information System (INIS)

Przybilla, B.; Eberlein-Koenig, B.; Bergner, T.

1994-01-01

If not compensated in any way, depletion of the stratospheric ozone layer leads to an increase of UV-B radiation at the earth's surface, especially towards the short-wave range, which is biologically the more active. The most concerning effect here is that of UV-B induced skin reactions, in particular malignant skintumors (malignant melanoma, spinocellular carcinoma, basalioma), whose incidence is expected to increase in future. As some photoreactions can be inhibited or enhanced also by radiation outside their action spectrum, it is possible for changes in solar spectral radiation flux density to influence photo-induced reactions that are driven at wavelengths outside the UV-B range. The authors have performed studies for developing methods of quantifying individual UV sensitivity. In vitro studies have shown that UV-A dependent photoreactions can be partly inhibited by UV-B. A number of drugs, as well as sulphites, which are used as preservatives amongst other things, have been shown to have phototoxic properties that may be relevant to photocarcinogenesis. Irradiation tests on cell cultures for different UV-B ranges have shown that irradiation at shorter wavelengths leads to a stronger release of proinflammatory cytokines that ar longer wavelengths with the same dose. Altogether it can be said that despite compelling theoretical evidence it is not easily possible to predict the actual consequences of an increase in particular of short-wave UV-B radiation at the earth's surface. The assumed effects must be examined individually by appropriate methods. (orig.) [de

Photosynthesis and pigment production in Liquidambar styraciflua - developmental and UV-B radiation effects

International Nuclear Information System (INIS)

Dillenburg, L.R.; Sullivan, J.H.; Teramura, A.H.

1993-01-01

Leaf expansion is very sensitive to different environmental stresses. This study describes ontogenetic changes in leaf size and physiology of Liquidambar styraciflua seedlings grown under UV-B irradiance levels simulating 0% (control), 16% (low) and 25% (high) stratospheric ozone reductions. Leaf size, light- and CO 2 -saturated rates of O 2 evolution (A max ), and concentration of chlorophylls (chl), and UV-B absorbing pigments were measured over a 4-week period. Specific leaf weight, A max and chl concentration increased with leaf age, except for a peak in A max at early development. Chlorophyll b concentration increased at a slower rate than chl a. Recently unfurled leaves has the greatest concentration of UV-B absorbing pigments. The effect of UV-B radiation on leaf growth and physiology were small and not dose-dependent. Expansion of leaves exposed to low UV-B was slightly delayed compared to controls (1.663 vs. 1.90 cm 2 /day), but final leaf size was unaffected by UV-B radiation. Physiological effects were less pronounced during the rapid expansion period. High UV-B tended to promote, while low UV-B inhibited accumulation of chl, especially chl a. In contrast, concentration of UV-B absorbing compounds was promoted only by low UV-B. The small inhibitory effects of UV-B on leaf growth and physiology suggests a high tolerance of the species to damaging UV-B radiation

Anti-Melanogenic Potentials of Nanoparticles from Calli of Resveratrol-Enriched Rice against UVB-Induced Hyperpigmentation in Guinea Pig Skin.

Science.gov (United States)

Lee, Taek Hwan; Kang, Ji Hee; Seo, Jae Ok; Baek, So-Hyeon; Moh, Sang Hyun; Chae, Jae Kyoung; Park, Yong Un; Ko, Young Tag; Kim, Sun Yeou

2016-01-01

We already reported that genetically engineered resveratrol-enriched rice (RR) showed to down-regulate skin melanogenesis. To be developed to increase the bioactivity of RR using calli from plants, RR was adopted for mass production using plant tissue culture technologies. In addition, high-pressure homogenization (HPH) was used to increase the biocompatibility and penetration of the calli from RR into the skin. We aimed to develop anti-melanogenic agents incorporating calli of RR (cRR) and nanoparticles by high-pressure homogenization, examining the synergistic effects on the inhibition of UVB-induced hyperpigmentation. Depigmentation was observed following topical application of micro-cRR, nano-calli of normal rice (cNR), and nano-cRR to ultraviolet B (UVB)-stimulated hyperpigmented guinea pig dorsal skin. Colorimetric analysis, tyrosinase immunostaining, and Fontana-Masson staining for UVB-promoted melanin were performed. Nano-cRR inhibited changes in the melanin color index caused by UVB-promoted hyperpigmentation, and demonstrated stronger anti-melanogenic potential than micro-cRR. In epidermal skin, nano-cRR repressed UVB-promoted melanin granules, thereby suppressing hyperpigmentation. The UVB-enhanced, highly expressed tyrosinase in the basal layer of the epidermis was inhibited by nano-cRR more prominently than by micro-cRR and nano-cNR. The anti-melanogenic potency of nano-cRR also depended on pH and particle size. Nano-cRR shows promising potential to regulate skin pigmentation following UVB exposure.

UVB shielding role of FeCl3 and certain cyanobacterial pigments

International Nuclear Information System (INIS)

Kumar, A.; Tyagi, M.B.; Srinivas, G.; Singh, N.; Kumar, H.D.; Sinha, R.P.; Friedrich-Alexander-Universitaet, Erlangen; Haeder, D.P.

1996-01-01

The shielding role of ferric iron (FeCl 3 ) and certain cyanobacterial pigments (a brown-colored pigment from Scytonema hofmanii culture filtrate and a pink extract from Nostoc spongiaeforme) against UVB-induced damage in the filamentous, nitrogen-fixing cyanobacterium Nostoc muscorum has been demonstrated. Addition of these colored compounds to agarose gels (1-3 mm thick) resulted in a considerable decrease in UVB transmittance through the gels. The lowest UVB transmittance (15%) occurred through a 3 mm gel containing 0.01% FeCl 3 , followed by S. hofmanii culture filtrate (40%) and N. spongiaeforme extract (50%). These substances appear to act as very efficient UVB-absorbing screens. Percent survival and 14 CO 2 uptake of N. muscorum increased significantly if UVB exposure was given on gels containing FeCl 3 or other UVB-shielding substances. The highest protection of N. muscorum was recorded with FeCl 3 , followed by S. hofmanii culture filtrate and N. spongiaeforme extract. Such UV-shielding substances if present in required concentration range may enhance the survival of cyanobacteria exposed to high levels of UVB. (author)

The effects of UV-B radiation on European heathland species

International Nuclear Information System (INIS)

Björn, L.O.; Callaghan, T.V.; Johnsen, I.; Lee, J.A.; Manetas, Y.; Paul, N.D.; Sonesson, M.; Wellburn, A.R.; Coop, D.; Heide-Jørgensen, H.S.; Gehrke, C.; Gwynn-Jones, D.; Johanson, U.; Kyparissis, A.; Levizou, E.; Nikolopoulos, D.; Petropoulou, Y.; Stephanou, M.

1997-01-01

The effects of enhanced UV-B radiation on three examples of European shrub-dominated vegetation were studied in situ. The experiments were in High Arctic Greenland, northern Sweden and Greece, and at all sites investigated the interaction of enhanced UV-B radiation (simulating a 15% reduction in the ozone layer) with artificially increased precipitation. The Swedish experiment also involved a study of the interaction between enhanced UV-B radiation and elevated CO 2 (600 ppm). These field studies were supported by an outdoor controlled environment study in the United Kingdom involving modulated enhancement of UV-B radiation in combination with elevated CO 2 (700 ppm). Effects of the treatments on plant growth, morphology, phenology and physiology were measured. The effects observed were species specific, and included both positive and negative responses to the treatments. In general the negative responses to UV-B treatments of up to three growing seasons were small, but included reductions in shoot growth and premature leaf senescence. Positive responses included a marked increase in flowering in some species and a stimulation of some photosynthetic processes. UV-B treatment enhanced the drought tolerance of Pinus pinea and Pinus halepensis by increasing leaf cuticle thickness. In general, there were few interactions between the elevated CO 2 and enhanced UV-B treatments. There was evidence to suggest that although the negative responses to the treatments were small, damage may be increasing with time in some long-lived woody perennials. There was also evidence in the third year of treatments for effects of UV-B on insect herbivory in Vaccinium species. The experiments point to the necessity for long-term field investigations to predict the likely ecological consequences of increasing UV-B radiation. (author)

Effects of ultraviolet-B radiation on fish: Histologic comparison of a UVB-sensitive and a UVB-tolerant species

Science.gov (United States)

Blazer, V.S.; Fabacher, D.L.; Little, E.E.; Ewing, M.S.; Kocan, K.M.

1997-01-01

Lahontan cutthroat trout Oncorhynchus clarki henshawi were sensitive to simulated solar ultraviolet-B radiation (UVB) and exhibited grossly visible signs of sunburn upon exposure. Razorback suckers Xyrauchen texanus, however, were tolerant to simulated solar UVB and showed no grossly visible signs of exposure. Cutthroat trout also had considerably less of an unidentified, possibly photoprotective, substance in the skin than did razorback suckers. In all attempt to characterize the cellular response to simulated solar UVB exposure in the skin of these two species, we examined sections from UVB-exposed fish by light and electron microscopy. Cutthroat trout showed grossly visible signs of sunburn by 48 h. Histologic observations included a sloughing of the mucous cells, necrosis and edema in the epidermis and dermis, and, in some cases, secondary fungal infections. Razorback suckers did not show any visible signs of sunburn during 72 h of experimental exposure. Histologic analyses revealed that cell necrosis had occurred, but the severe necrosis and sloughing noted in cutthroat trout was not observed. An increase in epidermal thickness, apparently due to hypertrophy and hyperplasia of large PAS-negative cells, occurred in the razorback suckers. These cells contained a large central region of low electron density and appeared to be club cells. In some, extensive interdigitation of the electron-lucent cytoplasm with adjacent epithelial cell margins occurred. Near the surface of the epidermis these cells were larger and the interface with epithelial cells lacked complex interdigitation. These cells may contain the substance that appears to protect razorback suckers against UV-B radiation.

Effects of UVB radiation on net community production in the upper global ocean

KAUST Repository

Garcia-Corral, Lara S.

2016-08-31

Aim Erosion of the stratospheric ozone layer together with oligotrophication of the subtropical ocean is leading to enhanced exposure to ultraviolet B (UVB) radiation in ocean surface waters. The impact of increased exposure to UVB on planktonic primary producers and heterotrophs is uncertain. Here we test the null hypothesis that net community production (NCP) of plankton communities in surface waters of the tropical and subtropical ocean is not affected by ambient UVB radiation and extend this test to the global ocean, including the polar oceans and the Mediterranean Sea using previous results. Location We conducted experiments with 131 surface communities sampled during a circumnavigation cruise along the tropical and subtropical ocean and combined these results with 89 previous reports encompassing the Atlantic, Pacific, Arctic and Southern Oceans and the Mediterranean Sea. Methods The use of quartz (transparent to UVB radiation) and borosilicate glass materials (opaque to most UVB) for incubations allowed us to compare NCP between communities where UVB is excluded and those receiving natural UVB radiation. Results We found that NCP varies when exposed to natural UVB radiation compared to those where UVB was removed. NCP of autotrophic communities tended to decrease under natural UVB radiation, whereas the NCP of heterotrophic communities tended to increase. However, these variations showed the opposite trend under higher levels of UVB radiation. Main conclusions Our results suggest that earlier estimates of NCP for surface communities, which were hitherto derived using materials blocking UVB radiation were biased, with the direction and magnitude of this bias depending on the metabolic status of the communities and the underwater penetration of UVB radiation.

UV-B damage amplified by transposons in maize

International Nuclear Information System (INIS)

Walbot, V.

1999-01-01

While absorbing visible light energy for photosynthesis, plants are unavoidably exposed to ultraviolet radiation, which is particularly harmful at shorter wavelengths (UV-B radiation). Ozone depletion in the atmosphere means that plants receive episodic or steadily increasing doses of UV-B, which damages their photosynthetic reaction centres, crosslinks cellular proteins, and induces mutagenic DNA lesions. Plant adaptive mechanisms of shielding and repair are therefore critical to survival — for example, somatic tissues of maize and Arabidopsis defective in phenolic sunscreen pigments incur increased DNA damage, and mutants defective in DNA repair are killed by UV-B

Sinapate esters provide greater UV-B attenuation than flavonoids in Arabidopsis thaliana (Brassicaceae)

International Nuclear Information System (INIS)

Sheahan, J.J.

1996-01-01

Mutants affected in flavonoid (tt4) or sinapate ester (fah1) biosynthesis were used to assess the relative importance of these phenolic UV photoprotectants in Arabidopsis. Flavonoid and sinapate ester absorption was more specific for UV-B than major nonphenolic chromophores in crude extracts. A new method of evaluating phenolic UV-B attenuation was developed using fluorescence analysis. When excited by UV-B, sinapate ester containing leaves and cotyledons had enhanced sinapate ester fluorescence and reduced chlorophyll fluorescence relative to those without sinapate esters. Although fluorescence analysis gave no evidence of UV-B attenuation by flavonoids, enhanced chlorophyll and protein loss were observed upon UV-B exposure in flavonoid-deficient leaves, suggesting they have another mechanism of UV-B protection. The hydroxycinnamates have been largely ignored as UV-B attenuating pigments. and the results indicate that greater attention should be paid to their role in attenuating UV-B

Ambient UV-B radiation decreases photosynthesis in high arctic Vaccinium uliginosum

Energy Technology Data Exchange (ETDEWEB)

Albert, K.R.; Ro-Poulsen, H. (Univ. of Copenhagen, Dept. of Terrestrial Ecology, Copenhagen (DK)); Mikkelsen, T.N. (Technical Univ. of Denmark, Risoe National Laboratory for Sustainable Energy, Biosystems Dept., Roskilde (DK))

2008-06-15

An UV-B-exclusion experiment was established in high arctic Zackenberg, Northeast Greenland, to investigate the possible effects of ambient UV-B on plant performance. During almost a whole growing season, canopy gas exchange and Chl fluorescence were measured on Vaccinium uliginosum (bog blueberry). Leaf area, biomass, carbon, nitrogen and UV-B-absorbing compounds were determined from a late season harvest. Compared with the reduced UV-B treatment, the plants in ambient UV-B were found to have a higher content of UV-B-absorbing compounds, and canopy net photosynthesis was as an average 23% lower during the season. By means of the JIP-test, it was found that the potential of processing light energy through the photosynthetic machinery was slightly reduced in ambient UV-B. This indicates that not only the UV-B effects on PSII may be responsible for some of the observed reduction of photosynthesis but also the effects on other parts of the photosynthetic machinery, e.g. the Calvin cycle, might be important. The 60% reduction of the UV-B irradiance used in this study implies a higher relative change in the UV-B load than many of the supplemental experiments do, but the substantial effect on photosynthesis clearly indicates that V. uliginosum is negatively affected by the current level of UV-B. (au)

Ambient UV-B radiation decreases photosynthesis in high arctic Vaccinium uliginosum.

Science.gov (United States)

Albert, Kristian R; Mikkelsen, Teis N; Ro-Poulsen, Helge

2008-06-01

An UV-B-exclusion experiment was established in high arctic Zackenberg, Northeast Greenland, to investigate the possible effects of ambient UV-B on plant performance. During almost a whole growing season, canopy gas exchange and Chl fluorescence were measured on Vaccinium uliginosum (bog blueberry). Leaf area, biomass, carbon, nitrogen and UV-B-absorbing compounds were determined from a late season harvest. Compared with the reduced UV-B treatment, the plants in ambient UV-B were found to have a higher content of UV-B-absorbing compounds, and canopy net photosynthesis was as an average 23% lower during the season. By means of the JIP-test, it was found that the potential of processing light energy through the photosynthetic machinery was slightly reduced in ambient UV-B. This indicates that not only the UV-B effects on PSII may be responsible for some of the observed reduction of photosynthesis but also the effects on other parts of the photosynthetic machinery, e.g. the Calvin cycle, might be important. The 60% reduction of the UV-B irradiance used in this study implies a higher relative change in the UV-B load than many of the supplemental experiments do, but the substantial effect on photosynthesis clearly indicates that V. uliginosum is negatively affected by the current level of UV-B.

The effect of UV-B radiation on chloroplast translation in Pisum sativum

International Nuclear Information System (INIS)

Raab, M.M.; Jagendorf, A.T.

1990-01-01

UV-B radiation has previously been reported to reduce growth, flowering, and net photosynthesis. The present study examines the effect of UV-B radiation on isolated chloroplast of 7-10 day old pea seedlings. Amount of ( 3 H)-Leu incorporated into isolated chloroplasts was measured in the presence or absence of UV-B exposure. Preliminary experiments show a 30% inhibition of protein synthesis in isolated chloroplasts after only 20 mins of UV-B exposure (6.9 J/m 2 /30 min). Percent inhibition of chloroplast translation is directly correlated with UV-B exposure over a 60 min time span. Preliminary studies also show no change in both cold and radiolabeled protein profiles as expressed on 1-D PAGE and autofluorography. Comparative studies on the sensitivity of e - flow vs protein synthesis following UV-B exposure are underway. Further work on the role of oxygen free radicals and the specific site of action of UV-B damage to the translation machinery of chloroplasts will be discussed

(UVB)-induced DNA damage

African Journals Online (AJOL)

Jane

2011-08-17

dependent cytogenetic lesions were assessed by the micronucleus test (MNT). It was found that POE effectively reduced the extent of DNA breakages and cytogenetic lesions upon exposure to UVB (erythemal ultraviolet (EUV);.

UVB radiation and New Zealand agriculture

International Nuclear Information System (INIS)

Laing, W.

1993-01-01

UV has variable effects on plant growth and yields. Over 300 species have been screened for UVB sensitivity, and over half showed sensitivity. In some cases, UV has been shown to reduce yields of some varieties while having little effect or even increasing the yields of others. These experiments included a wide variety of important crop plants (eg wheat, soybean, trees, (conifers) etc). The data show that selective breeding might be used to improve UVB tolerance of various important species. (author)

Ambient UV-B radiation decreases photosynthesis in high arctic Vaccinium uliginosum

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

2008-01-01

). Leaf area, biomass, carbon, nitrogen and UV-B-absorbing compounds were determined from a late season harvest. Compared with the reduced UV-B treatment, the plants in ambient UV-B were found to have a higher content of UV-B-absorbing compounds, and canopy net photosynthesis was as an average 23% lower...... during the season. By means of the JIP-test, it was found that the potential of processing light energy through the photosynthetic machinery was slightly reduced in ambient UV-B. This indicates that not only the UV-B effects on PSII may be responsible for some of the observed reduction of photosynthesis...... on photosynthesis clearly indicates that V. uliginosum is negatively affected by the current level of UV-B....

Exposure of vitamins to UVB and UVA radiation generates singlet oxygen.

Science.gov (United States)

Knak, Alena; Regensburger, Johannes; Maisch, Tim; Bäumler, Wolfgang

2014-05-01

Deleterious effects of UV radiation in tissue are usually attributed to different mechanisms. Absorption of UVB radiation in cell constituents like DNA causes photochemical reactions. Absorption of UVA radiation in endogenous photosensitizers like vitamins generates singlet oxygen via photosensitized reactions. We investigated two further mechanisms that might be involved in UV mediated cell tissue damage. Firstly, UVB radiation and vitamins also generate singlet oxygen. Secondly, UVB radiation may change the chemical structure of vitamins that may change the role of such endogenous photosensitizers in UVA mediated mechanisms. Vitamins were irradiated in solution using monochromatic UVB (308 nm) or UVA (330, 355, or 370 nm) radiation. Singlet oxygen was directly detected and quantified by its luminescence at 1270 nm. All investigated molecules generated singlet oxygen with a quantum yield ranging from 0.007 (vitamin D3) to 0.64 (nicotinamide) independent of the excitation wavelength. Moreover, pre-irradiation of vitamins with UVB changed their absorption in the UVB and UVA spectral range. Subsequently, molecules such as vitamin E and vitamin K1, which normally exhibit no singlet oxygen generation in the UVA, now produce singlet oxygen when exposed to UVA at 355 nm. This interplay of different UV sources is inevitable when applying serial or parallel irradiation with UVA and UVB in experiments in vitro. These results should be of particular importance for parallel irradiation with UVA and UVB in vivo, e.g. when exposing the skin to solar radiation.

UV-B effects on crops: response of the irrigated rice ecosystem

International Nuclear Information System (INIS)

Olszyk, D.; Dai, Q.; Teng, P.; Leung, H.; Luo, Y.; Peng, S.

1996-01-01

Increasing ultraviolet-B (UV-B) radiation resulting from depletion of the stratospheric ozone layer could have damaging effects on crops. This paper reviews recent findings on direct effects of UV-B on rice growth and yield as well as indirect effects via impacts on other organisms in the rice (Oryza sativa) agroecosystem. The findings are based on research by scientists at the International Rice Research Institute (IRRI) in Los Baños, the Philippines, and their collaborators in China and the United States; with comparison to research by scientists in other countries. Current results indicate that while enhanced UV-B directly impacts many aspects of rice growth, physiology, and biochemistry under controlled phytotron conditions; in general rice growth and yield are not affected under natural field conditions. The difference in response may be related both to the levels of UV-B exposure used in phytotron vs. field studies and the lower ratio of UV-A to UV-B in the phytotron compared to field. In terms of indirect effects on rice blast disease, enhanced UV-B affected both the fungus itself (Pyricularia grisea) and the susceptibility of the rice plant to the fungus. Based on these data, simulation models estimated potential impacts of higher UV-B levels on blast severity and rice yield in different countries of southeast and east Asia. Ultimately, results from rice studies can be used to identify strategies to minimize any negative effects of UV-B on rice productivity

Contrasting Responses of Marine and Freshwater Photosynthetic Organisms to UVB Radiation: A Meta-Analysis

KAUST Repository

Jin, Peng

2017-03-14

Ultraviolet-B (UVB) radiation is a global stressor that has profound impacts on freshwater and marine ecosystems. However, an analysis of the patterns of sensitivity to UVB radiation across aquatic photosynthetic organisms has not yet been published. Here, we performed a meta-analysis on results reported in 214 studies compiled from the published literature to quantify and compare the magnitude of responses of aquatic photosynthetic organisms to changes in UVB radiation. The meta-analysis was conducted on observations of marine (n = 893) and freshwater macroalgae (n = 126) and of marine (n = 1,087) and freshwater (n = 2,889) microalgae (total n = 4,995). Most of these studies (85%) analyzed the performance of organisms exposed to natural solar radiation when UVB was partially or totally reduced compared with the organismal performance under the full solar radiation spectrum, whereas the remaining 15% of the studies examined the responses of organisms to elevated UVB radiation mostly using artificial lamps. We found that marine photosynthetic organisms tend to be more sensitive than freshwater photosynthetic organisms to UVB radiation; responses to either decreased or increased UVB radiation vary among taxa; the mortality rate is the most sensitive of the trait responses to elevated UVB radiation, followed by changes in cellular and molecular traits; the sensitivity of microalgae to UVB radiation is dependent on size, with small-celled microalgae more sensitive than large-celled microalgae to UVB radiation. Thick macroalgae morphotypes were the less sensitive to UVB, but this effect could not be separated from phylogenetic differences. The high sensitivity of marine species, particularly the smallest photosynthetic organisms, to increased UVB radiation suggests that the oligotrophic ocean, a habitat comprising 70% of the world\\'s oceans with high UVB penetration and dominated by picoautotrophs, is extremely vulnerable to changes in UVB radiation.

Biological responses of two soybean cultivars exposed to enhanced UVB radiation

International Nuclear Information System (INIS)

D'Surney, S.J.; Tschaplinski, T.J.; Edwards, N.T.; Shugart, L.R.

1993-01-01

A UVB exposure and monitoring system has been established at the Oak Ridge National Laboratory's Global Climate Change Research Facility. The system consists of a power supply, and data acquisition and exposure equipment to accomplish controlled, elevated exposure of terrestrial plants to UVB. Plant biomass, selected compounds that absorb UV radiation, and DNA integrity/damage were measured for two soybean cultivars [Glycine max (L.) Merr.] Forrest and Essex exposed to elevated UVB (32% above ambient) in this system. The biomass of each major plant organ was observed to be less in soybean cultivar Forrest upon exposure to enhanced UVB with the greatest response in seed pods and stems. In contrast, soybean cultivar Essex showed no biomass response to elevated UVB. Enhanced UVB caused significant (P < 0.1) changes in concentrations of UV-absorbing compounds in both soybean cultivars. The Essex cultivar had an increase in UV-absorbing compounds, whereas a decline was observed for soybean Forrest. There was a decrease in the integrity of DNA, as measured by strand breaks, from both cultivars at 30 and 52 days to exposure. DNA pyrimidine dimers in isolated plant DNA were measured with Micrococcus luteus UV endonuclease. DNA from soybean Forrest exposed to UVB and sampled at 30 and 52 days of exposure had significantly greater (P<0.05) pyrimidine dimer concentration (dimer frequency ≈ 1 dimer per 28,000 DNA bases) than either cultivar exposed to UV treatment for 1 day or Essex at days 30–52 (dimer frequencies < /1 per 120,000 bases of DNA). Decrease in DNA integrity and biomass production in Forrest under elevated UVB may be related to the inability to maintain high concentrations of UV-absorbing compounds in leaves. The tolerant cultivar Essex increased the concentration of UV-absorbing compounds while maintaining biomass production and DNA integrity under elevated UVB

Impacts of UVB radiation on food consumption of forest specialist tadpoles.

Science.gov (United States)

Londero, James Eduardo Lago; Dos Santos, Caroline Peripolli; Segatto, Ana Lúcia Anversa; Passaglia Schuch, André

2017-09-01

Solar ultraviolet radiation B (UVB) is an important environmental stressor for amphibian populations due to its genotoxicity, especially in early developmental stages. Nonetheless, there is an absence of works focused on the UVB effects on tadpoles' food consumption efficiency. In this work, we investigated the effects of the exposure to a low environmental-simulated dose of UVB radiation on food consumption of tadpoles of the forest specialist Hypsiboas curupi [Hylidae, Anura] species. After UVB treatment tadpoles were divided and exposed to a visible light source or kept in the dark, in order to indirectly evaluate the efficiency of DNA repair performed by photolyases and nucleotide excision repair (NER), respectively. The body mass and the amount of food in tadpoles' guts were verified in both conditions and these data were complemented by the micronuclei frequency in blood cells. Furthermore, the keratinized labial tooth rows were analyzed in order to check for possible UVB-induced damage in this structure. Our results clearly show that the body weight decrease induced by UVB radiation occurs due to the reduction of tadpoles' food consumption. This behavior is directly correlated with the genotoxic impact of UVB light, since the micronuclei frequency significantly increased after treatments. Surprisingly, the results indicate that photoreactivation treatment was ineffective to restore the food consumption activity and body weight values, suggesting a low efficiency of photolyases enzymes in this species. In addition, UVB treatments induced a higher number of breaks in the keratinized labial tooth rows, which could be also associated with the decrease of food consumption. This work contributes to better understand the process of weight loss observed in tadpoles exposed to UVB radiation and emphasizes the susceptibility of forest specialist amphibian species to sunlight-induced genotoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

Growth and defense in deciduous trees and shrubs under UV-B

International Nuclear Information System (INIS)

Julkunen-Tiitto, Riitta; Haeggman, Hely; Aphalo, Pedro J.; Lavola, Anu; Tegelberg, Riitta; Veteli, Timo

2005-01-01

Reflection by waxy or resinous surface structures and hairs, repair reactions of biomolecules and induction of different sheltering components provide the means of plant protection from harmful solar UV-B radiation. Secondary products, especially flavonoids and phenolic acids as defense components are also important in plant tolerance to UV-B, fulfilling the dual role as screens that reduce UV-B penetration in plant tissues, and as antioxidants protecting from damage by reactive oxidant species. Plants are sensitive to UV-B radiation, and this sensitivity can be even more clone-specific than species-specific. The results available in the literature for deciduous trees and shrubs indicate that UV-B radiation may affect several directions in the interaction of woody species with biotic (herbivores) and abiotic (CO 2 and nutrition) factors depending on the specific interaction in question. These multilevel interactions should have moderate ecological significance via the overall changed performance of woody species and shrubs. - The growth performance of deciduous trees and shrubs under UV-B irradiation is constrained by multilevel interactions with many abiotic and biotic factors

The effect of exposure to enhanced UV-B radiation on the penetration of monochromatic and polychromatic UV-B radiation in leaves of Brassica napus

International Nuclear Information System (INIS)

Cen, Y.-P.; Bornman, J.F.

1993-01-01

Using quartz optical fibres, penetration of both monochromatic (310 nm) and polychromatic UV-B (280–320 nm) radiation in leaves of Brassica napus L. (cv. Ceres) was measured. Plants were grown under either visible light (750 μmol m −2 s −1 photosynthetically active radiation) or with the addition of 8. 9 KJ m −2 day −1 biologically effective UV-B (UV-B BE ) radiation. Results showed that of the 310 nm radiation that penetreated the leaf, 90% was within the intial one third of the leaf with high attenuation in the leaf epidermis, especially in UV-treated plants. Polychromatic UV-B radiation, relative to incident radiation, showed a relatively uniform spectral distribution within the leaf, except for collimated radiation. Over 30% of the UV-screening pigments in the leaf, including flavonoids, were found in the adaxial epidermal layer, making this layer less transparent to UV-B radiation than the abaxial epidermis, which contained less than 12% of the UV-screening pigments. UV-screening pigments increased by 20% in UV-treated leaves relative to control leaves. Densely arranged epicuticular wax on the adaxial leaf surface of UV-treated plants may have further decreased penetration of UV-B radiation by reflectance. An increased leaf thickness, and decreases in leaf area and leaf dry weight were also found for UV-treated plants. (author)

Seasonal responses of six Poaceae to differential levels of solar UV-B radiation

International Nuclear Information System (INIS)

Deckmyn, G.; Impens, I.

1999-01-01

The effects of changes in solar UV-B on the growth and pigmentation of six grass species from cold-temperate grasslands (Lolium perenne, Lolium multiflorum, Festuca arundinacea, Festuca rubra, Phleum pratense and Dactylis glomerata) in spring and summer were studied. The grasses were grown in greenhouses with different foils, resulting in three treatments: no UV-B, 80% of ambient and 90% of ambient UV-BBE (biologically effective UV-B). The results indicated important effects of ambient UV-B levels on grass, but the different species reacted in very different ways. Both morphology and biomass production were influenced by UV-B in some species. However, changes in biomass production did not necessarily occur within the same species as changes in morphology. The grasses were more sensitive in summer. Overall, only F. rubra was positively influenced by UV-B under all circumstances. The biomass of D. glomerata and L. perenne was reduced by UV-B in spring and summer. Morphological changes included reduced height and increased tillering. The sensitivity of the different species was partially explained by their ability to reduce their specific leaf area in response to UV-B. Only the more sensitive species showed increased production of protective pigments. Overall, there were important differences between the effect of a low level of UV-B, and the further increase in UV-B, indicating that several mechanisms are operating at different light levels. (author)

Effects of UV-B radiation on the isoflavone accumulation and physiological-biochemical changes of soybean during germination: Physiological-biochemical change of germinated soybean induced by UV-B.

Science.gov (United States)

Ma, Meng; Wang, Pei; Yang, Runqiang; Gu, Zhenxin

2018-06-01

In this study, the effects of UV-B radiation on the isoflavones accumulation, physiological and nutritional quality, water status, and characteristics of proteins in germinated soybeans were investigated. The results showed that isoflavones content in soybeans increased with appropriate intensity and time of UV-B radiation and decreased with excessive treatment. Fresh weight, length, free amino acids, reducing sugar contents and bulk water (T 23 ) in germinated soybeans decreased with increasing radiation time, indicating that UV-B inhibited the growth and nutrients metabolism of soybean during germination. Cell damage was detected in germinated soybeans with excessive UV-B radiation, as shown by the black spots in cotyledons and the increased intercellular water determined by LF-NMR. Germination resulted in an increase in random coil structures, while UV-B radiation induced no obvious changes in FT-IR spectrum and protein conformation of soybeans. Both UV-B radiation and germination caused the increase in soluble proteins, especially in 1.0-75.0 kDa fraction. Copyright © 2018 Elsevier Ltd. All rights reserved.

UV-B radiation and photosynthetic irradiance acclimate eggplant for outdoor exposure

International Nuclear Information System (INIS)

Latimer, J.G.; Mitchell, G.A.

1987-01-01

Treatment of greenhouse-grown eggplant (Solanum melongena L. var. esculentum Nees. 'Burpee's Black Beauty') seedlings with supplemental photosynthetically active radiation from cool-white fluorescent lamps increased growth of plants subsequently transferred outdoors relative to growth of plants that received no supplemental radiation or were shaded to 45% of solar irradiation in the greenhouse before transfer outdoors. Eggplant seedlings transferred outdoors were placed under plastic tarps either to provide relative protection from solar ultraviolet-B (UV-B) radiation (280-315 nm) using Mylar film or to allow exposure to UV-B using cellulose acetate. Protection of seedlings from UV-B radiation resulted in greater leaf expansion than for UV-B-exposed seedlings, but no change in leaf or shoot dry weight occurred after 9 days of treatment. Specific leaf weight increased in response to UV-B exposure outdoors. Exposure of eggplant to UV-B radiation from fluorescent sunlamps in the greenhouse also decreased leaf expansion and leaf and shoot dry weight gain after 5 days of treatment. However, there were no differences in leaf or shoot dry weight relative to control plants after 12 days of UV-B treatment, indicating that UV-B treated plants had acclimated to the treatment and actually had caught up with non-UV-B-irradiated plants in terms of growth

UVB shielding role of FeCl{sub 3} and certain cyanobacterial pigments

Energy Technology Data Exchange (ETDEWEB)

Kumar, A.; Tyagi, M.B.; Srinivas, G.; Singh, N.; Kumar, H.D. [Banaras Hindu Univ., Varanasi (India). Dept. of Botany; Sinha, R.P. [Banaras Hindu Univ., Varanasi (India). Dept. of Botany]|[Friedrich-Alexander-Universitaet, Erlangen (Germany). Institut fuer Botanik und Pharmazeutische Biologie; Haeder, D.P. [Friedrich-Alexander-Universitaet, Erlangen (Germany). Institut fuer Botanik und Pharmazeutische Biologie

1996-08-01

The shielding role of ferric iron (FeCl{sub 3}) and certain cyanobacterial pigments (a brown-colored pigment from Scytonema hofmanii culture filtrate and a pink extract from Nostoc spongiaeforme) against UVB-induced damage in the filamentous, nitrogen-fixing cyanobacterium Nostoc muscorum has been demonstrated. Addition of these colored compounds to agarose gels (1-3 mm thick) resulted in a considerable decrease in UVB transmittance through the gels. The lowest UVB transmittance (15%) occurred through a 3 mm gel containing 0.01% FeCl{sub 3}, followed by S. hofmanii culture filtrate (40%) and N. spongiaeforme extract (50%). These substances appear to act as very efficient UVB-absorbing screens. Percent survival and {sup 14}CO{sub 2} uptake of N. muscorum increased significantly if UVB exposure was given on gels containing FeCl{sub 3} or other UVB-shielding substances. The highest protection of N. muscorum was recorded with FeCl{sub 3}, followed by S. hofmanii culture filtrate and N. spongiaeforme extract. Such UV-shielding substances if present in required concentration range may enhance the survival of cyanobacteria exposed to high levels of UVB. (author).

UV-B Radiation Induces Root Bending Through the Flavonoid-Mediated Auxin Pathway in Arabidopsis.

Science.gov (United States)

Wan, Jinpeng; Zhang, Ping; Wang, Ruling; Sun, Liangliang; Wang, Wenying; Zhou, Huakun; Xu, Jin

2018-01-01

Ultraviolet (UV)-B radiation-induced root bending has been reported; however, the underlying mechanisms largely remain unclear. Here, we investigate whether and how auxin and flavonoids are involved in UV-B radiation-induced root bending in Arabidopsis using physiological, pharmacological, and genetic approaches. UV-B radiation modulated the direction of root growth by decreasing IAA biosynthesis and affecting auxin distribution in the root tips, where reduced auxin accumulation and asymmetric auxin distribution were observed. UV-B radiation increased the distribution of auxin on the nonradiated side of the root tips, promoting growth and causing root bending. Further analysis indicated that UV-B induced an asymmetric accumulation of flavonoids; this pathway is involved in modulating the accumulation and asymmetric distribution of auxin in root tips and the subsequent redirection of root growth by altering the distribution of auxin carriers in response to UV-B radiation. Taken together, our results indicate that UV-B radiation-induced root bending occurred through a flavonoid-mediated phototropic response to UV-B radiation.

UVB-induced systemic immunosuppression: role of mast cells and histamine

International Nuclear Information System (INIS)

Hart, P.H.; Grimbaldeston, M.A.; Finlay-Jones, J.J.

1999-01-01

Full text: UVB radiation (290-320 nm) is immunosuppressive by multiple mechanisms allowing the outgrowth of UV-induced tumours in both mouse and man. Furthermore, patients with non-melanoma skin cancers have a higher risk of death from other cancers which could be explained by UV-induced immunomodulation. The mechanism(s) of suppression by UVB depend on whether the sensitising antigen is applied to the irradiated site ('local') or to non-irradiated sites ('systemic'). In the former, the activity of UV-induced TNFα is important as it affects the migration of Langerhans cells to draining lymph nodes. In contrast, histamine from dermal mast cells is critical to the early events by which UVB can suppress systemic immune responses. The prevalence of dermal mast cells in 7 strains and substrains of mice correlates directly with their susceptibility to UVB-induced systemic immunosuppression. Furthermore, mast cell depleted mice (Wf/Wf) are resistant to UVB-induced systemic immunomodulation. However, they become susceptible after reconstitution of the site to be irradiated with bone marrow derived mast cell precursors. The mice also gain susceptibility to cis-urocanic acid-induced systemic immunomodulation. There is considerable evidence that histamine is the mast cell product critical to downstream immunosuppressive events. Firstly, physiological concentrations of histamine suppress contact hypersensitivity responses. Secondly, histamine receptor antagonists halve UVB-induced systemic immunosuppression. Thirdly, mice with different UVB-susceptibilities are equally susceptible to histamine-induced immunosuppression, and finally, histamine can suppress contact hypersensitivity responses in Wf/Wf mice. We suggest that histamine may be immunomodulatory by multiple pathways. Histamine can induce the production of immunosuppressive prostanoids from keratinocytes. A lymphocyte-derived, histamine-induced suppressor factor was reported in the 1970's. More recently histamine has

DNA metabolism in peripheral lymphocytes of UV-B wholebody irradiated men

International Nuclear Information System (INIS)

Klein, W.; Kocsis, F.; Altmann, H.

1983-02-01

Healthy probands were UV-B irradiated and different times after the treatment blood was taken and lymphocytes were isolated. Semiconservative DNA-synthesis was enhanced after 4 in vivo expositions. DNA repair replication in lymphocytes after in vitro UV-C damage was initially increased in UV-B wholebody irradiated people. With nucleoidsedimentation DNA strand breaks after in vivo UV-B irradiation were detected. (Author) [de

Continuous-flow solar UVB disinfection reactor for drinking water.

Science.gov (United States)

Mbonimpa, Eric Gentil; Vadheim, Bryan; Blatchley, Ernest R

2012-05-01

Access to safe, reliable sources of drinking water is a long-standing problem among people in developing countries. Sustainable solutions to these problems often involve point-of-use or community-scale water treatment systems that rely on locally-available resources and expertise. This philosophy was used in the development of a continuous-flow, solar UVB disinfection system. Numerical modeling of solar UVB spectral irradiance was used to define temporal variations in spectral irradiance at several geographically-distinct locations. The results of these simulations indicated that a solar UVB system would benefit from incorporation of a device to amplify ambient UVB fluence rate. A compound parabolic collector (CPC) was selected for this purpose. Design of the CPC was based on numerical simulations that accounted for the shape of the collector and reflectance. Based on these simulations, a prototype CPC was constructed using materials that would be available and inexpensive in many developing countries. A UVB-transparent pipe was positioned in the focal area of the CPC; water was pumped through the pipe to allow exposure of waterborne microbes to germicidal solar UVB radiation. The system was demonstrated to be effective for inactivation of Escherichia coli, and DNA-weighted UV dose was shown to govern reactor performance. The design of the reactor is expected to scale linearly, and improvements in process performance (relative to results from the prototype) can be expected by use of larger CPC geometry, inclusion of better reflective materials, and application in areas with greater ambient solar UV spectral irradiance than the location of the prototype tests. The system is expected to have application for water treatment among communities in (developing) countries in near-equatorial and tropical locations. It may also have application for disaster relief or military field operations, as well as in water treatment in areas of developed countries that receive

Protective effects of oleum curcumae wenchowensis on skin damage due to UVB

International Nuclear Information System (INIS)

Wang Zhicheng; Zhao Hongguang; Du Xiang; Li Yanbo; Guo Wei; Gong Shouliang; Xiao Jian; Yao Chongshun; Li Xiaokun

2006-01-01

Objective: To study the protective effects of oleum curcumae wenchowensis on skin damage exposed to UVB and its mechanism, and to provide the experimental basis for the protection of skin damage exposed to UVB. Methods: The skin of guinea pigs was exposed to UVB (28.38 J/cm 2 · 30 d) to establish the oxidative damage model. The skin erythema and the rough were observed during the experiment; the thickness of epiderm and the number of fibroblast were observed under light microscope after the experiment. The activities of GSH-Px, SOD, CAT and T-AOC and the contain of MDA in the supernate of skin homogenate were detected with biochemical methods. Results: The epiderm in UVB exposure group and blank group thickened, but that in protective group weren't observed; the number of fibroblast in UVB exposure group and blank group decreased, while that in protective group increased, but that in control group didn't. The content of MDA in the supemate of skin homogenate in UVB exposure group and blank group increased, but that in protective group deceased, and the activities of GSH-Px, SOD, CAT and T-AOC in UVB exposure group and blank group decreased, but those in protective group increased, and control group had no change. Conclusions: Oleum curcumae wenchowensis has the protective effects on skin damage exposed to UVB, which may be mediated by increasing the contain of antioxidases and eliminating the flee radical. (authors)

Plant responses to UV-B irradiation are modified by UV-A irradiation

International Nuclear Information System (INIS)

Middleton, E.M.; Teramura, A.H.

1993-01-01

The increasing UV-B radiation (0.28-0.32 μm) reaching the earth's surface is an important concern. Plant response in artificial UV-B irradiation studies has been difficult to assess, especially regarding photosynthetic pigments, because the fluorescent lamps also produce UV-A (0.32-0.40μm) radiation which is involved with blue light in pigment synthesis. Both UV-A and UV-B irradiances were controlled in two glasshouse experiments conducted under relatively high PPFD (> 1300μmol m -2 s -1 ) at two biologically effective daily UV-B irradiances (10.7 and 14.1 kJ m -2 ); UV-A irradiances were matched in Controls (∼5, 9 kJ m -2 ). Normal, chlorophyll-deficient, and flavonoid-deficient isolines of soybean cultivar, Clark, were utilized. Many growth/ pigment variables exhibited a statistically significant interaction between light quality and quantity: in general, UV-A radiation moderated the damaging effects of UV-B radiation. Regression analyses demonstrated that a single negative function related photosynthetic efficiency to carotenoid Content (r 2 =0.73, P≤0.001), implying a open-quotes costclose quotes in maintaining carotenoids for photoprotection. A stomatal limitation to photosynthesis was verified and carotenoid content was correlated with UV-B absorbing compound levels, in UV-B irradiated plants

Reproductive, morphological, and phytochemical responses of Arabidopsis thaliana ecotypes to enhanced UV-B radiation

Energy Technology Data Exchange (ETDEWEB)

Trumbull, V.L.; McCloud, E.S.; Paige, K.N. (Univ. of Illinois, Urbana, IL (United States))

1994-06-01

Two ecotypes of Arabidopsis thaliana, collected from Libya and Norway, were grown in the greenhouse under. UV-B doses of 0 and 10.5 kJ m[sup [minus]2] UV-B[sub BE]. The high UV-B dose simulated midsummer ambient conditions over Libya and a 40% reduction in stratospheric ozone over Norway. The Libyan ectotype, which originated from latitudes where solar UV-B is high, showed no UV-B induced damage to plant growth. However the Norwegian ecotype, which originated from latitudes where solar UV-B is low, showed a significant reduction in plant height, inflorescence weight, and rosette weight in response to enhanced UV-B. Although fruit and seed number for both ecotypes were unaffected by enhanced UV-B radiation the germination success of the seeds harvested from the irradiated Norwegian plants were significantly reduced. The two ecotypes also differed with respect to their accumulation of kaempferol, a putative UV-B protective filter. The Libyan ecotype increased kaempferol concentration by 38% over the 0 kJ treatment whereas the Norwegian ecotype increased by only 15%. These data suggest that, for these ecotypes, variation in UV-B sensitivity may be explained by the differential induction of UV-absorbing leaf pigments.

Effect of enhanced UV-B radiation on motile microorganisms

International Nuclear Information System (INIS)

Haeder, D.P.

1985-02-01

The effect of slightly increased UV-B radiation was studied in four taxonomically very different microorganisms: the gliding prokaryotic cyanobacterium, Phormidium, the unicellular green alga Cosmarium, the flagellate Euglena and the cellular slime mold Dictyostelium. UV-B doses which can be expected as a result of a slight decrease of the protective ozone layer in the stratosphere, do not kill or damage the microorganisms visibly. However, such UV-B doses impair the development, motility and photoorientation of these organisms. Due to the inhibition of these physiological important parameters the organisms cannot respond adequately to the changing factors in their environment, which prevents the survival of the populations. (orig.) [de

Plant Responses to Increased UV-B Radiation: A Research Project

Science.gov (United States)

DAntoni, H. L.; Skiles, J. W.; Armstrong, R.; Coughlan, J.; Daleo, G.; Mayoral, A.; Lawless, James G. (Technical Monitor)

1994-01-01

Ozone decrease implies more ultraviolet-B (UV-B) radiation reaching the surface of the Earth. Increased UV-B radiation triggers responses by living organisms. Despite the large potential impacts on vegetation, little is known about UV-B effects on terrestrial ecosystems. Long-term ecological studies are needed to quantify the effects of increased UV radiation on terrestrial ecosystems, asses the risks, and produce reliable data for prediction. Screening pigments are part of one of the protective mechanism in plants. Higher concentrations of screening pigments in leaves may be interpreted as a response to increased UV radiation. If the screening effect is not sufficient, important molecules will be disturbed by incoming radiation. Thus, genetics, photosynthesis, growth, plant and leaf shape and size, and pollen grains may be affected. This will have an impact on ecosystem dynamics, structure and productivity. It is necessary to monitor selected terrestrial ecosystems to permit detection and interpretation of changes attributable to global climate change and depleted ozone shield. The objectives of this project are: (1) To identify and measure indicators of the effects of increased solar UV-B radiation on terrestrial plants; (2) to select indicators with the greatest responses to UV-B exposure; (3) to test, adapt or create ecosystem models that use the information gathered by this project for prediction and to enhance our understanding of the effects of increased UV-B radiation on terrestrial ecosystems. As a first step to achieve these objectives we propose a three-year study of forest and steppe vegetation on the North slope of the Brooks Range (within the Arctic circle, in Alaska), in the Saguaro National Monument (near Tucson, Arizona) and in the forests and steppes of Patagonia (Argentina). We selected (1) vegetation north of the Polar Circle because at 70N there is 8% risk of plant damage due to increased UV-B radiation; (2) the foothills of Catalina Mountains

Saponins from Tribulus terrestris L. protect human keratinocytes from UVB-induced damage.

Science.gov (United States)

Sisto, Margherita; Lisi, Sabrina; D'Amore, Massimo; De Lucro, Raffaella; Carati, Davide; Castellana, Donatello; La Pesa, Velia; Zuccarello, Vincenzo; Lofrumento, Dario D

2012-12-05

Chronic exposure to solar UVB radiation damages skin, increasing the risk to develop cancer. Hence the identification of compounds with a photoprotective efficacy is essential. This study examined the role of saponins derived from Tribulus terrestris L. (TT) on the modulation of apoptosis in normal human keratinocytes (NHEK) exposed to physiological doses of UVB and to evaluate their antitumoral properties. In NHEK, TT saponins attenuate UVB-induced programmed cell death through inhibition of intrinsic apoptotic pathway. In squamous cell carcinomas (SCC) TT saponins do not make the malignant keratinocytes more resistant to UVB and determine an enhanced apoptotic response. The photoprotective effect of TT saponins is tightly correlated to the enhancement of NER genes expression and the block of UVB-mediated NF-κB activation. Collectively, our study shows experimental evidence that TT has a preventive efficacy against UVB-induced carcinogenesis and the molecular knowledge on the mechanisms through which TT saponins regulate cell death suggests great potential for TT to be developed into a new medicine for cancer patients. Copyright © 2012 Elsevier B.V. All rights reserved.

Alleviation of UV-B stress in Arabidopsis using tea catechins

African Journals Online (AJOL)

STORAGESEVER

2008-11-19

Nov 19, 2008 ... synthase gene and lighter stress of the UV-B exposed plant. ... mechanism of tea catechins against UV-B stress is considered to be their sunscreen property .... ZRX-1000DC, Qianjiang Instruments and Equipment Co. Ltd.,.

The UV-B Photoreceptor UVR8: From Structure to Physiology

Science.gov (United States)

Jenkins, Gareth I.

2014-01-01

Low doses of UV-B light (280 to 315 nm) elicit photomorphogenic responses in plants that modify biochemical composition, photosynthetic competence, morphogenesis, and defense. UV RESISTANCE LOCUS8 (UVR8) mediates photomorphogenic responses to UV-B by regulating transcription of a set of target genes. UVR8 differs from other known photoreceptors in that it uses specific Trp amino acids instead of a prosthetic chromophore for light absorption during UV-B photoreception. Absorption of UV-B dissociates the UVR8 dimer into monomers, initiating signal transduction through interaction with CONSTITUTIVELY PHOTOMORPHOGENIC1. However, much remains to be learned about the physiological role of UVR8 and its interaction with other signaling pathways, the molecular mechanism of UVR8 photoreception, how the UVR8 protein initiates signaling, how it is regulated, and how UVR8 regulates transcription of its target genes. PMID:24481075

Evaluating the combined effects of pretilachlor and UV-B on two Azolla species.

Science.gov (United States)

Prasad, Sheo Mohan; Kumar, Sushil; Parihar, Parul; Singh, Anita; Singh, Rachana

2016-03-01

The present study assessed the comparative responses of two agronomic species of Azolla (A.microphylla and A. pinnata) exposed to man-made and natural stressors by evaluating biomass accumulation, pigments (chlorophyll a and b and carotenoid contents), photosynthetic activity and nitrogen metabolism. The study was carried out in field where two species of Azolla were cultured and treated with various concentrations (5, 10 and 20 μg ml(-1)) of herbicide; pretilachlor [2-chloro-2,6-diethyl-N-(2-propoxyethyl) acetanilide] and enhanced levels (UV-B1: ambient +2.2 kJ m(-2) day(-1) and UV-B2: ambient +4.4 kJ m(-2) day(-1)) of UV-B, alone as well as in combination. Biomass accumulation, photosynthetic pigments; chlorophyll a, b and carotenoids, photosynthetic oxygen yield and photosynthetic electron transport activities i.e. photosystem II (PS II) and photosystem I (PS I) in both the species declined with the increasing doses of pretilachlor and UV-B radiation, which further declined when applied in combination. The lower doses (5 and 10 μg ml(-1)) of pretilachlor and UV-B (UV-B1 and UV-B2) alone, damaged mainly the oxidation side of PS II, whereas higher dose (20 μg ml(-1)) of pretilachlor alone and in combination with UV-B1 and UV-B2 caused damage to PS II reaction centre and beyond this towards the reduction side. A significant enhancement in respiration was also noticed in fronds of both the Azolla species following pretilachlor and UV-B treatment, hence indicating strong damaging effect. The nitrate assimilating enzymes - nitrate reductase and nitrite reductase and ammonium assimilating enzymes - glutamine synthetase and glutamate synthase were also severely affected when treated either with pretilachlor and/or UV-B while glutamate dehydrogenase exhibited a stimulatory response. The study suggests that both the species of Azolla showed considerable damage under pretilachlor and UV-B treatments alone, however, in combination the effect was more intense. Further, in

Hydration and transparency of the rabbit cornea irradiated with UVB-doses of 0.25 J/cm(2) and 0.5 J/cm(2) compared with equivalent UVB radiation exposure reaching the human cornea from sunlight.

Science.gov (United States)

Cejka, Cestmír; Ardan, Taras; Sirc, Jakub; Michálek, Jiří; Beneš, Jiří; Brůnová, Blanka; Rosina, Jozef

2011-07-01

Exposure of the cornea to UV radiation from sunlight evokes intraocular inflammation, photokeratitis. Photokeratitis is caused by UVB radiation. It is accompanied by changes of corneal hydration and light absorption. The aim of this study was to examine the effect of two UVB doses on corneal optics in rabbits and to compare these UVB doses with the equivalent exposure of UVB radiation reaching the human cornea from sunlight. Rabbit corneas were irradiated with a daily UVB dose of 0.25 J/cm(2) or 0.5 J/cm(2) for 4 days. One day after finishing the irradiations the rabbits were sacrificed and corneal light absorption measured using our spectrophotometrical method. Corneal hydration was examined using an ultrasonic Pachymeter every experimental day before the irradiation procedure and the last day before sacrificing the animals. Changes in corneal optics appeared after the repeated exposure of the cornea to a UVB dose of 0.25 J/ cm(2) and massively increased after the repeated exposure of the cornea to a UVB dose of 0.5 J/cm(2). The first significant changes in corneal hydration appeared after a single exposure of the cornea to a UVB dose of 0.25 J/cm(2). Changes in corneal hydration appeared after the exposure of the rabbit cornea to a single UVB dose equivalent to 2.6 hours of solar UVB radiation reaching the human cornea, as measured by UVB sensors embedded in the eyes of mannequin heads facing the sun on a beach at noon in July. Repeated exposure of the rabbit cornea to the same UVB dose evoked profound changes in corneal optics. Although comparison of experimental and outdoor conditions are only approximate, the results in rabbits point to the danger for the human eye from UVB radiation when short stays in sunlight are repeated for several consecutive days without UV protection.

Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, Helge

2011-01-01

Ambient ultraviolet-B (UV-B) radiation potentially impacts the photosynthetic performance of high Arctic plants. We conducted an UV-B exclusion experiment in a dwarf shrub heath in NE Greenland (74°N), with open control, filter control, UV-B filtering and UV-AB filtering, all in combination......, nitrogen and UV-B absorbing compounds. Compared to a 60% reduced UV-B irradiance, the ambient solar UV-B reduced net photosynthesis in Salix arctica leaves fixed in the 45° position which exposed leaves to maximum natural irradiance. Also a reduced Calvin Cycle capacity was found, i.e. the maximum rate...... across position in the vegetation. These findings add to the evidence that the ambient solar UV-B currently is a significant stress factor for plants in high Arctic Greenland....

Adverse Effects of UV-B Radiation on Plants Growing at Schirmacher Oasis, East Antarctica.

Science.gov (United States)

Singh, Jaswant; Singh, Rudra P

2014-01-01

This study aimed to assess the impacts of ultraviolet-B (UV-B) radiation over a 28-day period on the levels of pigments of Umbilicaria aprina and Bryum argenteum growing in field. The depletion of stratospheric ozone is most prominent over Antarctica, which receives more UV-B radiation than most other parts of the planet. Although UV-B radiation adversely affects all flora, Antarctic plants are better equipped to survive the damaging effects of UV-B owing to defenses provided by UV-B absorbing compounds and other screening pigments. The UV-B radiations and daily average ozone values were measured by sun photometer and the photosynthetic pigments were analyzed by the standard spectrophotometric methods of exposed and unexposed selected plants. The daily average atmospheric ozone values were recorded from 5 January to 2 February 2008. The maximum daily average for ozone (310.7 Dobson Units (DU)) was recorded on 10 January 2008. On that day, average UV-B spectral irradiances were 0.016, 0.071, and 0.186 W m(-2) at wavelengths of 305, 312, and 320 nm, respectively. The minimum daily average ozone value (278.6 DU) was recorded on 31 January 2008. On that day, average UV-B spectral irradiances were 0.018, 0.085, and 0.210 W m(-2) at wavelengths of 305, 312, and 320 nm, respectively. Our results concludes that following prolonged UV-B exposure, total chlorophyll levels decreased gradually in both species, whereas levels of UV-B absorbing compounds, phenolics, and carotenoids gradually increased.

Photomorphogenic effects of UV-B radiation on plants: consequences for light competition

International Nuclear Information System (INIS)

Barnes, P.W.; Ballaré, C.L.; Caldwell, M.M.

1996-01-01

A combination of field and labotatory studies were conducted to explore the nature of photomorphogenic effects of ultraviolet-B radiation (UV-B; 280–320 nm) on plant morphology and to evaluate the ecological consequences of these alterations in morphology for interspecific competition. Under laboratory conditions, seedlings of cucumber (Cucumis sativus L.) and tomato (Lycopersicon esculentum Mill.) exhibited appreciable (ca. 50%) and rapid (< 3h) inhibition in hypocotyl elongation in response to UV-B exposure. In cucumber, this inhibition was reversible, occurred without any associated changes in dry matter production and was caused by UV-B incident on the cotyledons and not the stem or growing tip. Inhibition of stem elongation in etiolated tomato seedlings occurred at least 3 h prior to the onset of accumulation of UV-absorbing pigments and monochromatic UV supplied against a background of visible radiation revealed maximum effectiveness in inhibition around 300 nm. Collectively, these findings suggest that a specific, but yet unidentified, UV-B photoreceptor is involved in mediating certain morphological responses to UV-B. For mixtures of wheat (Triticum aestivum L.) and wild oat (Avena fatua L.), a common weedy competitor, supplemental UV-B irradiation in the field differentially altered shoot morphology which resulted in changes in canopy structure, light interception and calculated stand photosynthesis. It is argued that, because of its asymmetrical nature, competition for light can potentially amplify the effects of UV-B on shoot morphology and may, therefore, be an important mechanism by which changes in the solar UV-B spectrum associated with stratospheric ozone reduction could alter the composition and character of terrestrial vegetation

Mean Annual UV-B Irradiance

Data.gov (United States)

U.S. Environmental Protection Agency — Ultraviolet-B (UV-B) radiation is the most energetic part of sunlight reaching the Earth's surface (wavelength region is 280 to 315 nm), and it has been shown to...

Growth, photosynthesis and UV-B absorbing compounds of Portuguese Barbela wheat exposed to ultraviolet-B radiation

International Nuclear Information System (INIS)

Correia, C.M.; Torres-Pereira, M.S.; Torres-Pereira, J.M.G.

1999-01-01

Wheat plants (Triticum aestivum L.) were exposed to two levels of UV-B radiation (ambient UV-B and high UV-B, simulating a 20% reduction in the ozone layer) under mediterranean field-growth conditions. After 4 months of UV-B treatment, total plant biomass of high UV-B plants was 18% lower compared to control plants. The decrease of biomass appears to be the result of changes in morphological and physiological processes. High UV-B treatment induces decreases in leaf area, net photosynthesis rate, transpiration rate and water use efficiency. Pigment analysis of leaf extracts showed increases in chlorophyll content and no effect on accumulation of UV-B absorbing pigments. The underlying mechanisms for these results are discussed. (author)

Antioxidant Responses Induced by UVB Radiation in Deschampsia antarctica Desv.

Directory of Open Access Journals (Sweden)

Hans Köhler

2017-05-01

Full Text Available Deschampsia antarctica Desv. is one of two vascular plants that live in the Maritime Antarctic Territory and is exposed to high levels of ultraviolet-B (UVB radiation. In this work, antioxidant physiology of D. antarctica was studied in response to UVB induced oxidative changes. Samples were collected from Antarctica and maintained in vitro culture during 2 years. Plants were sub-cultured in a hydroponic system and exposed to 21.4 kJ m-2 day-1, emulating summer Antarctic conditions. Results showed rapid and significant increases in reactive oxygen species (ROS at 3 h, which rapidly decreased. No dramatic changes were observed in photosynthetic efficiency, chlorophyll content, and level of thiobarbituric acid reactive species (MDA. The enzymatic (superoxide dismutase, SOD and total peroxidases, POD and non-enzymatic antioxidant activity (total phenolic increased significantly in response to UVB treatment. These findings suggest that tolerance of D. antarctica to UVB radiation could be attributed to its ability to activate both enzymatic and non-enzymatic antioxidant systems.

Experimental skin carcinoma by UVB application

Directory of Open Access Journals (Sweden)

Andrada Iftode

2016-12-01

Full Text Available OBJECTIVES AND BACKGROUND The aim of this research study was to evaluate the harmful effects at skin level induced by concomitant and repeated exposure to three toxic agents: UVB radiation, DMBA and TPA. MATERIALS AND METHODS Experimental mice were divided in thw following groups (n=5 mice/group: group 1 – healthy mice, group 2 – mice exposed to UVB – radiation and topical administration of acetone and group 3 – mice exposed to UVB – radiation and topical application of DMBA and TPA solutions (phase I - double tumor initiation and phase II - tumor promotion. RESULTS Application of these compounds led to the development of skin papilloma and to significant changes in skin parameters. CONCLUSIONS The barrier function of the skin was degraded in UVB exposed mice. DMBA and TPA depended on carcinogens schedule and corelated with skin carcinoma. Graphical abstract: Schematic protocol of experimental skin carcinoma REFERENCES 1. Lee Ja, Ko Jh, Jung Bg, Kim Th, Hong Ji, Park Ys, Lee Bj. Fermented Prunus mume with Probiotics Inhibits 7,12- Dimethylbenz[a]anthracene and 12-OTetradecanoyl phorbol-13-acetate Induced Skin Carcinogenesis through Alleviation of Oxidative Stress. Asian Pac J Cancer Prev. 2013;14:2973-2978. 2. Firooz A, Sadr B, Babakoohi S, Sarraf-Yazdy M, Fanian F, Kazerouni-Timsar A, NassiriKashani M, Naghizadeh MM, Dowlati Y. Variation of Biophysical Parameters of the Skin with Age, Gender, and Body Region. Scientific World Journal. 2012; doi.org/10.1100/2012/386936 3. Gheorgheosu (Coricovac D, Borcan F, Balasz NI, Soica C, Simu G, Kemeny L, Dehelean CA. Evaluation of skin parameters in C57BL/6J mice exposed to chemical and environmental factors using non-invasive methods. J Agroalim Proc Technol. 2014;20:14-20.

Effect of UV-B radiation on biomass production, pigmentation and protein content of marine diatoms

International Nuclear Information System (INIS)

Doehler, G.

1984-01-01

Several species of marine diatoms were grown at + 18 0 C and + 22 0 C under normal air conditions (0.035 vol.% CO 2 ) at a light/dark alteration of 14.8 h. Intensity of white light was 1 mW (approx.= 5000 lux). An artifical nutrient solution of 35per mille salinity was used. Algae - harvested during exponential growth - were exposed to different intensities of UV-B radiation (439, 717 and 1230 J m -2 m -1 ) for 2 days. UV-B radiation depressed the growth of all tested marine diatoms. Low levels of UV-B resulted in a slight increase of the biomass production (dry weight) compared to not UV-B treated cells. Enhanced UV-B doses caused a diminution of the primary productivity in all species. Algae exposed to UV-B stress showed a marked decrease in the protein and pigment content (chlorophyll a, chlorophyll c 1 + c 2 and carotenoids). In + 22 0 C grown cells of Lauderia annulata and Thalassiosira rotula were more sensitive to UV-B radiation than those cultures grown at + 18 0 C. Bellerochea yucatanensis cells grown at + 22 0 C were less affected after UV-B exposure than at + 18 0 C grown algae. The UV-B sensibility and growth of the individual species varied in a mixture of several marine diatoms. Results were discussed with reference to the UV-B effect on metabolic processes. (orig.)

Study of hemoglobin response to mid-ultraviolet (UVB) radiation using micro-Raman spectroscopy

Science.gov (United States)

Huang, Y. Y.; Li, N.; Zhou, S. N.; Huang, Z. T.; Zhuang, Z. F.

2017-09-01

Confocal micro-Raman spectroscopy is employed to monitor the damage to haemoglobin from mid-ultraviolet (UVB) radiation. We obtained the Raman spectra of an erythrocyte, which indicated that a peroxidation reaction occurs after UVB radiation. Further, the surface enhanced Raman scattering (SERS) spectra of isolated haemoglobin show that the intensities of the 1375 and 1399 cm-1 bands, which are markers of haem aggregation, obviously increase with prolonged UVB irradiation. This increase reveals that haem aggregation occurs in the peroxidation of erythrocytes. The UV-Vis spectra of isolated haemoglobin indicate that the Soret band, which is indicative of excitonic interactions in the aggregated haems, has a redshift ( 12 nm) after 30 min of UVB irradiation of erythrocytes. It can be deduced that an excitonic interaction occurs in the aggregated haems, which is caused by haemoglobin denaturation following UVB irradiation. In addition, the changes of the Raman marker bands during aggregation primarily originate from excitonic interactions. Throughout the process, a higher UVB radiation dose causes greater damage to haemoglobin.

Effects of UV-B radiation on wax biosynthesis

International Nuclear Information System (INIS)

Barnes, J.; Paul, N.; Percy, K.; Broadbent, P.; McLaughlin, C.; Mullineaux, P.; Creissen, G.; Wellburn, A.

1994-01-01

Two genotypes of tobacco (Nicotiana tabacum L.) were exposed in controlled environment chambers to three levels of biologically effective ultraviolet-B radiation (UV-B BE ; 280-320nm): 0, 4.54 (ambient) and 5.66 (∼ 25% enhancement) kJ m -2 d -1 . After 28 days, the quantity of wax deposited on leaf surfaces was determined gravimetrically; epicuticular wax chemical composition was determined by capillary gas chromatography with homologue assignments confirmed by gas chromatography-mass spectrometry. Leaf wettability was assessed by measuring the contact angle of water droplets placed on leaf surfaces. Tobacco wax consisted of three major hydrocarbon classes: Straight-chain alkanes (C 27 -C 33 ) which comprised ∼ 59% of the hydrocarbon fraction, containing a predominance of odd-chain alkanes with C 31 as the most abundant homologue; branched-chain alkanes (C 25 -C 32 ) which comprised ∼38% of the hydrocarbon fraction with anteiso 3-methyltriacontane (C 30 ) as the predominant homologue; and fatty acids (C 14 -C 18 ) which comprised ∼ 3% of the wax. Exposure to enhanced UV-B radiation reduced the quantity of wax on the adaxial surface of the transgenic mutant, and resulted in marked changes in the chemical composition of the wax on the exposed leaf surface. Enhanced UV-B decreased the quantity of straight-chain alkanes, increased the quantity of branched-chain alkanes and fatty acids, and resulted in shifts toward shorter straight-chain lengths. Furthermore, UV-B-induced changes in wax composition were associated with increased wettability of tobacco leaf surfaces. Overall, the data are consistent with the view that UV-B radiation has a direct and fundamental effect on wax biosynthesis. Relationships between the physico-chemical nature of the leaf surface and sensitivity to UV-B radiation are discussed. (orig.)

Australian UVB measurements programme

International Nuclear Information System (INIS)

Forgan, B.W.

1993-01-01

Australia's scientific community and industry are involved in a number of programs and projects with regard to UVB monitoring. Those indicated below are related to either long term monitoring programs or to the atmospheric science community. They are not meant to be exhaustive but can be used as a reference guide. (author)

Differences in the immunologic reactivity of mice treated with UVB or methoxsalen plus UVA radiation

International Nuclear Information System (INIS)

Kripke, M.L.; Morison, W.L.; Parrish, J.A.

1981-01-01

Skin tumors induced in mice by chronic exposure to UVB radiation are often highly antigenic and regress when transplanted into normal syngeneic animals, but grow progressively in immunosuppressed mice. Exposure of mice to subtumorigenic doses of UVB radiation can abolish this immunologic rejection phenomenon. In this study, we have investigated the effects of treatment with 8-methoxypsoralen plus UVA radiation (PUVA) on the rejection of antigenic UVB-induced tumors. PUVA treatment, with either topical or systemic administration of the psoralen, did not alter the normal process of rejection of UVB-induced tumors. Mice treated with both minimally and markedly phototoxic doses of PUVA rejected tumors with a frequency similar to that seen in untreated animals, although these tumors grew progressively in UVB-irradiated mice. These results indicate that the effects of PUVA treatment differ from those of UVB irradiation in that PUVA treatment does not alter the immunologic rejection of UVB-induced tumors

Ultraviolet B (UVB) induced DNA damage affects alternative splicing in skin cells

International Nuclear Information System (INIS)

Munoz, M.J.; Nieto Moreno, N.; Kornblihtt, A.R.

2010-01-01

The ultraviolet (UV) radiation from the Sun that reaches the Earth's surface is a combination of low (UVA, 320-400 nm) and high (UVB, 290-320 nm) energy light. UVB light causes two types of mutagenic DNA lesions: thymine dimers and (6-4) photo-products. UVB mutagenesis is a critical step in the generation of different forms of skin cancer, which develops almost exclusively in sun exposed areas. We have previously shown that RNA polymerase II (pol II) hyperphosphorylation induced by UVC (254 nm) irradiation of non-skin cells inhibits pol II elongation rates which in turn affects alternative splicing (AS) patterns, altering the synthesis of pro- and anti-apoptotic isoforms of key proteins like Bcl-x or Caspase 9 (C9). Since the UVC radiation is fully filtered by the ozone layer and AS regulation in skin pathologies has been poorly studied, we decided to extend our studies to human keratinocytes in culture treated with UVB (302 nm) light. We observed that pol II hyperphosphorylation is increased upon UVB irradiation, being this modification necessary for the observed change in AS of a model cassette exon. Moreover, UVB irradiation induces the proapoptotic mRNA isoforms of Bcl-x and C9 consistently with a key role of AS in skin response to DNA damage. (authors)

Synergism between UV-B radiation and pathogen magnifies amphibian embryo mortality in nature

International Nuclear Information System (INIS)

Kiesecker, J.M.; Blaustein, R.

1995-01-01

Previous research has shown that amphibians have differential sensitivity to ultraviolet-B (UV-B) radiation. In some species, ambient levels of UV-B radiation cause embryonic mortality in nature. The detrimental effects of UV-B alone or with other agents may ultimately affect amphibians at the population level. Here, we experimentally demonstrate a synergistic effect between UV-B radiation and a pathogenic fungus in the field that increases the mortality of amphibian embryos compared with either factor alone. Studies investigating single factors for causes of amphibian egg mortality or population declines may not reveal the complex factors involved in declines

The protective roles of TiO2 nanoparticles against UV-B toxicity in Daphnia magna.

Science.gov (United States)

Liu, Jie; Wang, Wen-Xiong

2017-09-01

Aquatic environments are increasingly under environmental stress due to ultraviolet (UV) radiation and potential inputs of nanoparticles with intense application of nanotechnology. In this study, we investigated the interaction between UV-B radiation and titanium nanoparticles (TiO 2 -NPs) in a model freshwater cladoceran Daphnia magna. UV-B toxicity to Daphnia magna was examined when the daphnids were exposed to a range of TiO 2 -NPs concentrations with an initial 5 or 10min of 200μW/cm 2 UV-B radiation. In addition, UV-B toxicity was also examined in the presence of TiO 2 -NPs in the body of daphnids. Our results demonstrated that the daphnid mortality under UV-B radiation decreased significantly in the presence of TiO 2 -NPs both in the water and in the body, indicating that TiO 2 -NPs had some protective effects on D. magna against UV-B. Such protective effect was mainly caused by the blockage of UV-B by TiO 2 -NPs adsorption. UV-B produced reactive oxygen species (ROS) in the water and in the daphnids, which was not sufficient to cause mortality of daphnids over short periods of radiation. Previous studies focused on the effects of TiO 2 -NPs on the toxicity of total UV radiation, and did not attempt to differentiate the potential diverse roles of UV-A and UV-B. Our study indicated that TiO 2 -NPs may conversely protect the UV-B toxicity to daphnids. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of UVB on flavonoid biosynthesis in wild type and mutant petunia and arabidopsis

International Nuclear Information System (INIS)

Ryan, K.G.; Swinny, E.E.; Markham, K.R.; Winefield, C.

2000-01-01

Full text: Flavonoids may protect plants against damage by UVB radiation. Flavonoid composition and mRNA expression were determined following growth of plants under natural light, and under natural light with low UVB and with enhanced UVB. In wild-type Arabidopsis and Petunia, UVB induced an increase in total levels of flavonols and this was due to an up-regulation of, several genes coding for key enzymes in the phenylpropanoid pathway. In addition, UVB induced a higher rate of production of the di-hydroxylated si flavonol, quercetin glycoside than of the mono-hydroxylated equivalent, of kaempferol glycoside. Thus the ratio of quercetin to kaempferol increased with UVB treatment in wild type plants, and this suggests that the flavonoid r 3'hydroxylase (F3'H) enzyme, which converts dihydrokaempferol to dihydroquercetin, may play a key role in plant protection from UVB. Mutant plants of both species lacking this F3'H gene were grown under similar UV conditions. Leaves of the mutant Arabidopsis plant (tt7) did not contain quercetin, even under the enhanced UVB treatment. Under the low UVB treatment the total amount of flavonol was similar to the wild-type (Ler), but with increasing UVB, total flavonol (i.e. kaempferol) levels were significantly higher than in similarly treated wild type plants. In the Petunia F3'H mutant, low levels of quercetin were found even in the low UVB treatment, which indicates this variety may be producing some quercetin via an alternative pathway. Under UVB radiation, total flavonoids increased to levels significantly higher than in similarly treated wild type plants, and most of this material was kaempferol. These observations suggest that quercetin is the preferred protective flavonol in wild type plants, due perhaps to enhanced antioxidant or free radical scavenging activity. In mutant plants lacking the F3'H enzyme, the response is to produce a larger amount of a less effective photoprotectant

Non-photosynthetic mechanisms of growth reduction in pea (Pisum sativum L.) exposed to UV-B radiation

International Nuclear Information System (INIS)

Gonzalez, R.; Mepsted, R.; Wellburn, A.R.; Paul, N.D.

1998-01-01

Pisum sativum cv. Guido grown under controlled environment conditions was exposed to either low or high UV-B radiation (2·2 or 9·9 kJ m –2 d –1 plant-weighted UV-B, respectively). Low or high UV-B was maintained throughout growth (LL and HH treatments, respectively) or plants were transferred between treatments when 22 d old (giving LH and HL treatments). High UV-B significantly reduced plant dry weight and significantly altered plant morphology. The growth and morphology of plants transferred from low to high UV-B were little affected, when compared with those of LL plants. By contrast, plants moved from high to low UV-B showed marked increases in growth when compared with HH plants. This contrast between HL and LH appeared to be related to the effect of UV-B on plant development. Exposure to high UV-B throughout development consistently reduced leaf areas. In fully expanded leaves there was no significant UV-B effect on cell area and reduced leaf area could be attributed to reduced cell number, suggesting effects on leaf primordia. Further reductions in the leaf area of younger leaves were the result of the slower development rate of plants grown at high UV-B, which also resulted in significant reductions in leaf number. (author)

Effects of Increased UVB radiation on plant-insect interactions: Plantago lanceolata and Junonia coenia

International Nuclear Information System (INIS)

McCloud, E.S.; Berenbaum, M.R.

1993-01-01

Seeds of P. lanceolata were collected from a local population and 4 replicates of 42 maternal families were grown for 90 days in the greenhouse with at two levels of supplemental UVB radiation (6 and 12 kJ day -1 BE 300 ). Higher UVB radiation increased leaf hair density and decreased plant size during early growth; family identity affected these also. Leaves excised from a subset of the plants were fed to ultimate instar larvae of J. coenia and assayed for iridoids. Increased UVB radiation did not alter the iridoid content of the leaves or the growth of the larvae. In a separate experiment, P. lanceolata growing under the two levels of UVB irradiation were infested with neonate larvae and larval growth was monitored. Larval growth was not markedly altered by enhanced UVB. These findings suggest that increased UVB is unlikely to alter the suitability of P. lanceolata as a host for J. coenia

Effect of UV-B on enzymes of nitrogen metabolism in the cyanobacterium Nostoc calcicola

International Nuclear Information System (INIS)

Kumar, A.; Sinha, R.P.; Häder, D. P.

1996-01-01

The effects of ultraviolet-B (UV-B; 280–315 nm) irradiation on nitrogenase and nitrate reductase (NR) activity have been studied in the filamentous and heterocystous N 2 -fixing cyanobacterium Nostoc calcicola. Exposure of cultures to UV-B (5W/m 2 ) for as little as 30 min caused complete inactivation of nitrogenase activity whereas nitrate reductase activity was stimulated twofold in comparison to one exposed to fluorescent white light. GS activity was also inhibited by UV-B treatment, but there was no total loss of activity even after 4 h. NR activity showed a gradual stimulation up to 4 h and thereafter it became constant. Stimulation was also obtained in reductant deficient cultures (12 h incubation in the dark) suggesting independence of NR of PS-II under UV-B. NR activity was also unaffected in the presence of DCMU, a known inhibitor of PS-II. However, both O 2 evolution and 14 CO 2 uptake were completely abolished following 30 min of UV-B treatment. Addition of the protein synthesis inhibitor chloramphenicol (25 μg/mL) to cultures did not show any inhibitory effect on NR activity. SDS-PAGE analysis of UV-B treated cultures elicited gradual loss of protein bands with increasing duration of exposure. Our findings suggest that UV-B irradiance has differential effects on the enzymes of the nitrogen metabolism in the cyanobacterium Nostoc calcicola. Further studies are needed to reveal the exact mechanism involved in the stimulation of NR activity by UV-B. Whether UV-B has a direct effect on NO 2 − accumulation in the cells needs detailed investigation. (author)

Sensitivity and Acclimation of Three Canopy-Forming Seaweeds to UVB Radiation and Warming

KAUST Repository

Xiao, Xi; de Bettignies, Thibaut; Olsen, Ylva S.; Agusti, Susana; Duarte, Carlos M.; Wernberg, Thomas

2015-01-01

Canopy-forming seaweeds, as primary producers and foundation species, provide key ecological services. Their responses to multiple stressors associated with climate change could therefore have important knock-on effects on the functioning of coastal ecosystems. We examined interactive effects of UVB radiation and warming on juveniles of three habitat-forming subtidal seaweeds from Western Australia–Ecklonia radiata, Scytothalia dorycarpa and Sargassum sp. Fronds were incubated for 14 days at 16–30°C with or without UVB radiation and growth, health status, photosynthetic performance, and light absorbance measured. Furthermore, we used empirical models from the metabolic theory of ecology to evaluate the sensitivity of these important seaweeds to ocean warming. Results indicated that responses to UVB and warming were species specific, with Sargassum showing highest tolerance to a broad range of temperatures. Scytothalia was most sensitive to elevated temperature based on the reduced maximum quantum yields of PSII; however, Ecklonia was most sensitive, according to the comparison of activation energy calculated from Arrhenius’ model. UVB radiation caused reduction in the growth, physiological responses and thallus health in all three species. Our findings indicate that Scytothalia was capable of acclimating in response to UVB and increasing its light absorption efficiency in the UV bands, probably by up-regulating synthesis of photoprotective compounds. The other two species did not acclimate over the two weeks of exposure to UVB. Overall, UVB and warming would severely inhibit the growth and photosynthesis of these canopy-forming seaweeds and decrease their coverage. Differences in the sensitivity and acclimation of major seaweed species to temperature and UVB may alter the balance between species in future seaweed communities under climate change.

Sensitivity and Acclimation of Three Canopy-Forming Seaweeds to UVB Radiation and Warming

KAUST Repository

Xiao, Xi

2015-12-02

Canopy-forming seaweeds, as primary producers and foundation species, provide key ecological services. Their responses to multiple stressors associated with climate change could therefore have important knock-on effects on the functioning of coastal ecosystems. We examined interactive effects of UVB radiation and warming on juveniles of three habitat-forming subtidal seaweeds from Western Australia–Ecklonia radiata, Scytothalia dorycarpa and Sargassum sp. Fronds were incubated for 14 days at 16–30°C with or without UVB radiation and growth, health status, photosynthetic performance, and light absorbance measured. Furthermore, we used empirical models from the metabolic theory of ecology to evaluate the sensitivity of these important seaweeds to ocean warming. Results indicated that responses to UVB and warming were species specific, with Sargassum showing highest tolerance to a broad range of temperatures. Scytothalia was most sensitive to elevated temperature based on the reduced maximum quantum yields of PSII; however, Ecklonia was most sensitive, according to the comparison of activation energy calculated from Arrhenius’ model. UVB radiation caused reduction in the growth, physiological responses and thallus health in all three species. Our findings indicate that Scytothalia was capable of acclimating in response to UVB and increasing its light absorption efficiency in the UV bands, probably by up-regulating synthesis of photoprotective compounds. The other two species did not acclimate over the two weeks of exposure to UVB. Overall, UVB and warming would severely inhibit the growth and photosynthesis of these canopy-forming seaweeds and decrease their coverage. Differences in the sensitivity and acclimation of major seaweed species to temperature and UVB may alter the balance between species in future seaweed communities under climate change.

Ecological and nonhuman biological effects of solar UV-B radiation

International Nuclear Information System (INIS)

Worrest, R.C.

1984-01-01

Recent studies regarding the impact of UV-B radiation upon ecological and nonhuman biological systems is the subject of the report. For years scientists and laymen alike have causally noted the impact of solar ultraviolet radiation upon the nonhuman component of the biosphere. Stratospheric ozone functions effectively as an ultraviolet screen by filtering out solar radiation in the 220-320 nm waveband as it penetrates through the atmosphere, thus allowing only small amounts of the longer wavelengths of radiation in the waveband to leak through to the surface of the earth. Although this radiation (UV-B radiation, 290-320 nm) comprises only a small fraction (lesser tha 1%) of the total solar spectrum, it can have a major impact on biological systems due to its actinic nature. Many organic molecules, most notably DNA, absorb UV-B radiation which can initiate photochemical reactions. It is life's ability, or lack thereof, to cope with enhanced levels of solar UV-B radiation that has generated concern over the potential depletion of stratospheric ozone

Effects of the ultraviolet-B radiation (UV-B) on conifers: a review

International Nuclear Information System (INIS)

Laakso, K.; Huttunen, S.

1998-01-01

The current knowledge on conifer responses to enhanced ultraviolet-B (UV-B) radiation is mainly based on greenhouse or growth chamber experiments of one growing season in duration. However, the biomass losses observed in greenhouses do not occur in field-grown trees in their natural habitats. Moreover, the majority of the 20 conifer species studied have been 1-year-old seedlings, and no studies have been undertaken on mature trees. Fully grown needles, with their glaucous waxy surfaces and thick epidermal cells with both soluble and wall-bound UV-B screening metabolites, are well protected against UV-B radiation. However, it is not known whether these are sufficient protectants in young emerging needles or during the early spring period of high UV-B levels reflected from snow. In order to understand all the mechanisms that result in the protection of conifer needles against UV-B radiation, future research should focus on the epidermal layer, separating the waxes, cuticle and epidermal and hypodermal cells. Parallel studies should consist of wall-bound and soluble secondary metabolite analysis, antioxidant measurements and microscopic observations. (author)

Pectins, ROS homeostasis and UV-B responses in plant roots.

Science.gov (United States)

Yokawa, Ken; Baluška, František

2015-04-01

Light from the sun contains far-red, visible and ultra violet (UV) wavelength regions. Almost all plant species have been evolved under the light environment. Interestingly, several photoreceptors, expressing both in shoots and roots, process the light information during the plant life cycle. Surprisingly, Arabidopsis root apices express besides the UVR8 UV-B receptor, also root-specific UV-B sensing proteins RUS1 and RUS2 linked to the polar cell-cell transport of auxin. In this mini-review, we focus on reactive oxygen species (ROS) signaling and possible roles of pectins internalized via endocytic vesicle recycling system in the root-specific UV-B perception and ROS homeostasis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Combined effects of water, nutrient, and UV-B stress on female fitness in Brassica (Brassicaceae)

International Nuclear Information System (INIS)

Conner, J.K.; Zangori, L.A.

1998-01-01

Our knowledge of the effects of increased levels of ultraviolet-B radiation (UV-B) on plant fitness is limited mainly to yield studies in a few crop species. Previous greenhouse and garden studies of Brassica have found greater detrimental effects of UV-B on fitness in gardens than in the greenhouse, suggesting the possibility that additional stresses in the field decrease the ability of Brassica to cope with UV-B. Possible interactions between UV-B and water/nutrient stress in determining plant fitness have rarely, if ever, been studied experimentally. Here we report measurements of female fitness in two species of Brassica in an experiment in which both UV-B and levels of water and nutrients were varied in a 2 X 2 factorial design. Water and nutrient stress reduced female fitness in both species, while UV-B caused fitness reductions in only one of the species. There was evidence for interactions between UV-B and water/nutrient stress for only a few of the traits measured; most traits, including those closely related to fitness, showed no evidence of an interaction

UV-B photoreceptor-mediated protection of the photosynthetic machinery in Chlamydomonas reinhardtii

Science.gov (United States)

Allorent, Guillaume; Lefebvre-Legendre, Linnka; Chappuis, Richard; Kuntz, Marcel; Truong, Thuy B.; Niyogi, Krishna K.; Goldschmidt-Clermont, Michel

2016-01-01

Life on earth is dependent on the photosynthetic conversion of light energy into chemical energy. However, absorption of excess sunlight can damage the photosynthetic machinery and limit photosynthetic activity, thereby affecting growth and productivity. Photosynthetic light harvesting can be down-regulated by nonphotochemical quenching (NPQ). A major component of NPQ is qE (energy-dependent nonphotochemical quenching), which allows dissipation of light energy as heat. Photodamage peaks in the UV-B part of the spectrum, but whether and how UV-B induces qE are unknown. Plants are responsive to UV-B via the UVR8 photoreceptor. Here, we report in the green alga Chlamydomonas reinhardtii that UVR8 induces accumulation of specific members of the light-harvesting complex (LHC) superfamily that contribute to qE, in particular LHC Stress-Related 1 (LHCSR1) and Photosystem II Subunit S (PSBS). The capacity for qE is strongly induced by UV-B, although the patterns of qE-related proteins accumulating in response to UV-B or to high light are clearly different. The competence for qE induced by acclimation to UV-B markedly contributes to photoprotection upon subsequent exposure to high light. Our study reveals an anterograde link between photoreceptor-mediated signaling in the nucleocytosolic compartment and the photoprotective regulation of photosynthetic activity in the chloroplast. PMID:27930292

UV-B photoreceptor-mediated protection of the photosynthetic machinery in Chlamydomonas reinhardtii.

Science.gov (United States)

Allorent, Guillaume; Lefebvre-Legendre, Linnka; Chappuis, Richard; Kuntz, Marcel; Truong, Thuy B; Niyogi, Krishna K; Ulm, Roman; Goldschmidt-Clermont, Michel

2016-12-20

Life on earth is dependent on the photosynthetic conversion of light energy into chemical energy. However, absorption of excess sunlight can damage the photosynthetic machinery and limit photosynthetic activity, thereby affecting growth and productivity. Photosynthetic light harvesting can be down-regulated by nonphotochemical quenching (NPQ). A major component of NPQ is qE (energy-dependent nonphotochemical quenching), which allows dissipation of light energy as heat. Photodamage peaks in the UV-B part of the spectrum, but whether and how UV-B induces qE are unknown. Plants are responsive to UV-B via the UVR8 photoreceptor. Here, we report in the green alga Chlamydomonas reinhardtii that UVR8 induces accumulation of specific members of the light-harvesting complex (LHC) superfamily that contribute to qE, in particular LHC Stress-Related 1 (LHCSR1) and Photosystem II Subunit S (PSBS). The capacity for qE is strongly induced by UV-B, although the patterns of qE-related proteins accumulating in response to UV-B or to high light are clearly different. The competence for qE induced by acclimation to UV-B markedly contributes to photoprotection upon subsequent exposure to high light. Our study reveals an anterograde link between photoreceptor-mediated signaling in the nucleocytosolic compartment and the photoprotective regulation of photosynthetic activity in the chloroplast.

Effect of UV-B radiation on the marine diatom bellerochea yucatanensis

International Nuclear Information System (INIS)

Doehler, G.

1982-01-01

There exists no information about the UV-B fluence on several photosynthetic products and nitrogen metabolism. The present report describes the effect of low levels of UV-B radiation on pigments, 14 C- and 15 N-incorporation of the marine diatom Bellerochea yucatanensis. (orig./AJ)

Rapid maize leaf and immature ear responses to UV-B radiation

International Nuclear Information System (INIS)

Casati, P.; Morrow, D.; Fernandes, J.; Walbot, V.

2011-01-01

Plants have evolved adaptations to environmental factors, including solar radiation. In addition to acting as a developmental and physiological signal, UV-B photons also cause cellular damage. Elevated UV-B radiation has pleiotropic effects on plant development, morphology, and physiology, but the regulation of systemic responses is not well-understood. To gain a better understanding of the initial events in UV-B acclimation, we have analyzed a 10min to 1h time course of transcriptome responses in irradiated and shielded leaves, and immature maize ears to unravel the systemic physiological and developmental responses in exposed and shielded organs. To identify metabolites as possible signaling molecules, we looked for compounds that increased within 5-90 min in both irradiated and shielded leaves, to explain the kinetics of profound transcript changes within 1h. We found that myoinositol is one such candidate metabolite, and it also has support from RNA profiling: after 1h UV-B, transcripts for myoinositol-1-phosphate synthase, are decreased in both irradiated and shielded leaves suggesting down-regulation of biogenesis. We also demonstrate that if 0.1mM myoinositol is applied to leaves of greenhouse maize, some metabolites that are changed by UV-B are also changed similarly by the chemical treatment. (author)

Diurnal changes in CN metabolism and response of rice seedlings to UV-B radiation.

Science.gov (United States)

Yun, Hyejin; Lim, Sunhyung; Kim, Yangmin X; Lee, Yejin; Lee, Seulbi; Lee, Deogbae; Park, Keewoong; Sung, Jwakyung

2018-03-13

Plants regulate a number of primary metabolites, including carbohydrates, organic acids, and amino acids, in response to UV-B radiation. Therefore, it is essential to understand the time-dependent response of rice plants to UV-B stress. This study focused on the response of plants to UV-B at different leaf developmental phases (emerging, growing, and maturing) in an attempt to fully comprehend the metabolic shift. We analyzed the expression levels of genes related to starch/sucrose metabolism in the leaf blades of rice seedlings (Oryza sativa L. "Saechuchenog") exposed to UV-B irradiation for short (1 day) and long terms (5 days) using quantitative real-time polymerase chain reaction. We also examined the diurnal variations in the contents of primary metabolites using an established GCTOF-MS (gas chromatography time of flight-mass spectrometry) method. The results showed that the levels of primary metabolites were largely dependent upon the diurnal rhythm and leaf developmental phase. The young leaves (sink) produced and accumulated starch rather than sucrose. The short-term (4 h, 1 day) UV-B exposure inhibited sucrose synthesis, which could be the first target of UV-B radiation. Following short- and long-term (5 days) exposure to UV-B radiation, the dynamic response of primary metabolites was evaluated. It was found that the content of carbohydrates decreased throughout the period of exposure to UV-B stress, especially in terms of sucrose concentration. However, the content of the majority of amino acids increased after an early decrease. Our data revealed that the metabolic response, as well as the gene expression, differed with the period (intensity) of exposure to UV-B radiation and with the phase of leaf development. These findings provide new insights for a better understanding of the metabolic response of a variety of plant species exposed to a wide range of UV-B radiation. Copyright © 2018. Published by Elsevier GmbH.

UVB-induced immune suppression and infection with Schistosoma mansoni

International Nuclear Information System (INIS)

Noonan, F.P.; Lewis, F.A.

1995-01-01

Irradiation with ultraviolet B (UVB, 290-320 nm) causes a systematic immunosuppression of cell-mediated immunity. The question of whether UV immunosuppression modulates the course of infectious diseases is important because UVB levels in sunlight are sufficient to predict significant UV-induced immunosuppression at most latitudes. We have investigated the effect of immunosuppressive doses of UVB on the disease caused by the helminth parasite Schistosoma mansoni. C57BL/6 mice were irradiated once or three times weekly over 60-80 days with UV from a bank of FS40 sunlamps. Each UV treatment consisted of an immunosuppressive UV dose, as determined by suppression of contact hypersensitivity to trinitrochlorobenzene, corresponding to about 15-30 min of noonday tropical sunlight exposure under ideal clear sky conditions. Cumulative UV doses were between 80 and 170 kJ/m 2 . Worm and egg burdens, liver granuloma diameters and liver fibrosis showed minimal changes ( 2 administered in six treatments) did not impair the resistance to rechallenge conferred by vaccination with 60 Co-irradiated cercariae. We have observed a dichotomy between UV immnosuppression and both disease and vaccination in this helminth infection, in contrast to the effects of UVB shown in other infectious diseases. (author)

Ultraviolet-B (280-320 nm) absorbing pigments in the leaves of Silene vulgaris: their role in UV-B tolerance

Energy Technology Data Exchange (ETDEWEB)

Staaij, J.W.M. van de; Ernst, W. H.O.; Hakvoort, H. W.J.; Rozema, J. [Vrije Univ., Amsterdam (Netherlands)

1995-07-01

The UV-B radiation tolerant perennial herb Silene vulgaris was tested on the influence of incident UV-B fluxes during growth on the synthesis of UV-B absorbing pigments in the leaves. Analysis of methanolic leaf extracts showed a stimulating effect of UV-B on the absorbing ability of leaf extracts. HPLC analysis made clear that UV-B radiation stimulated extractable flavonoid concentrations in leaves, but that UV-B absorption could only be partly attributed to these flavonoids. The contribution of flavonoids to UV-B absorption diminishes if plants mature. Other possible functions of flavonoids in plants growing under elevated UV-B conditions are discussed. (author)

Ultraviolet-B (280-320 nm) absorbing pigments in the leaves of Silene vulgaris: their role in UV-B tolerance

International Nuclear Information System (INIS)

Staaij, J.W.M. van de; Ernst, W.H.O.; Hakvoort, H.W.J.; Rozema, J.

1995-01-01

The UV-B radiation tolerant perennial herb Silene vulgaris was tested on the influence of incident UV-B fluxes during growth on the synthesis of UV-B absorbing pigments in the leaves. Analysis of methanolic leaf extracts showed a stimulating effect of UV-B on the absorbing ability of leaf extracts. HPLC analysis made clear that UV-B radiation stimulated extractable flavonoid concentrations in leaves, but that UV-B absorption could only be partly attributed to these flavonoids. The contribution of flavonoids to UV-B absorption diminishes if plants mature. Other possible functions of flavonoids in plants growing under elevated UV-B conditions are discussed. (author)

Effect of enhanced UV-B radiation on pollen quantity, quality, and seed yield in Brassica rapa (Brassicaceae)

International Nuclear Information System (INIS)

Demchik, S.M.; Day, T.A.

1996-01-01

Three experiments examined the influence of ultraviolet-B radiation (UV-B; 280-320 nm) exposure on reproduction in Brassica rapa (Brassicacaeae). Plants were grown in a greenhouse under three biologically effective UV-B levels that stimulated either an ambient stratospheric ozone level (control), 16% (open-quotes low enhancedclose quotes), or 32% (open-quotes high enhancedclose quotes) ozone depletion levels at Morgantown, WV, USA in mid-March. In the first experiment,pollen production and viability per flower were reduced by ∼50% under both enhanced UV-B levels relative to ambient controls. While plants under high-enhanced UV-B produced over 40% more flowers than plants under the two lower UV-B treatments, whole-plant production of viable pollen was reduced under low-enhanced UV-B to 34% of ambient controls. In the second experiment, the influence of source-plant UV-B exposure on in vitro pollen from plants was examined and whether source-plant UV-B exposure influenced in vitro pollen germination and viability. Pollen from plants under both enhanced-UV-B was reduced from 65 to 18%. Viability of the pollen from plants grown under both enhanced UV-B treatments was reduced to a much lesser extent: only from ∼43 to 22%. Thus, ambient source-plant pollen was more sensitive to enhanced UV-B levels to fertilize plants growing under ambient-UV-B levels, and assessed subsequent seed production and germination. Seed abortion rates were higher in plants pollinated with pollen from the enhanced UV-B treatments, than from ambient UV-B. Despite this, seed yield (number and mass) per plant was similar, regardless of the UV-B exposure of their pollen source. Our findings demonstrate that enhanced UV-B levels associated with springtime ozone depletion events have the capacity to substantially reduce viable pollen production, and could ultimately reduce reproductive success of B. rapa. 37 refs., 4 figs., 2 tabs

Effects of ultraviolet-B radiation (UV-B) on growth and physiology of the dune grassland species Calamagrostis epigeios

International Nuclear Information System (INIS)

Tosserams, M.; Rozema, J.

1995-01-01

Seedlings of Calamagrostis epigeios were exposed to four levels of UV-B radiation (280-320 nm), simulating up to 44% reduction of stratospheric ozone concentration during summertime in The Netherlands, to determine the response of this plant species to UV-B irradiation. After six weeks of UV-B treatment, total biomass of all UV-B treated plants was higher, compared to plants that had received no UV-B radiation. The increase of biomass did not appear to be the result of a stimulation of net photosynthesis. Also, transpiration rate and water use efficiency were not altered by UV-B at any exposure level. Pigment analysis of leaf extracts showed no effect of enhanced UV-B radiation on chlorophyll content and accumulation of UV absorbing pigments. UV-B irradiance, however, did reduce the transmittance of visible light (400-700 nm) of intact attached leaves, suggesting a change in anatomical characteristics of the leaves. Additionally, the importance of including an ambient UV-B treatment in indoor experiments is discussed

The effect of single and repeated UVB radiation on rabbit cornea.

Science.gov (United States)

Fris, Miroslav; Tessem, May-Britt; Cejková, Jitka; Midelfart, Anna

2006-12-01

Cumulative effect of ultraviolet radiation (UVR) is an important aspect of UV corneal damage. The purpose of this study was to apply high resolution magic angle spinning proton nuclear magnetic resonance (HR-MAS 1H NMR) spectroscopy to evaluate the effect of single and repeated UV radiation exposure of the same overall dose on the rabbit cornea. Corneal surfaces of 24 normal rabbit eyes were examined for the effects of UVB exposure (312 nm). In the first group (UVB1), animals were irradiated with a single dose (3.12 J/cm2; 21 min) of UVB radiation. The animals in the second group (UVB2) were irradiated three times for 7 min every other day (dose of 1.04 J/cm2; days 1, 3, 5) to give the same overall dose (3.12 J/cm2). The third group served as an untreated control group. One day after the last irradiation, the animals were sacrificed, and the corneas were removed and frozen. HR-MAS 1H NMR spectra from intact corneas were obtained. Special grouping patterns among the tissue samples and the relative percentage changes in particular metabolite concentrations were evaluated using modern statistical methods (multivariate analysis, one-way ANOVA). The metabolic profile of both groups of UVB-irradiated samples was significantly different from the control corneas. Substantial decreases in taurine, hypo-taurine and choline-derivatives concentrations and substantial elevation in glucose and betaine levels were observed following the UVR exposure. There was no significant difference between the effect of a single and repeated UVB irradiation of the same overall dose. For the first time, the effects of single and repeated UVR doses on the metabolic profile of the rabbit cornea were analysed and compared. The combination of HR-MAS 1H NMR spectroscopy and modern statistical methods (multivariate analysis, one-way ANOVA) proved suitable to assess the overall view of the metabolic alterations in the rabbit corneal tissue following UVB radiation exposure.

Crosstalk between MAV and MEP pathways in vitro grape plants exposed to UV-B radiation

International Nuclear Information System (INIS)

Gil, M.; Bottini, R.; Piccoli, P.; Pontin, M.

2010-01-01

The synthesis of terpenoids from IPP (isopentenyl diphosphate) proceeds in plants throughout two pathways, the MVA (mevalonic acid) in cytosol and the MEP (2-C-methyl-D-erythritol 4-phosphate) in plastids. Ultraviolet-B (UV-B) radiation induced the synthesis of terpenes in in vitro grape plants according to the fluence rate. Low intensity UV-B promoted the MVA pathway while high intensity UV-B stimulated the MEP pathway. Mevastatin is known to inhibit the enzyme HMG-CoA reductase blocking terpene synthesis in cytosol. In vitro plants growing 45 days under 16 h-photoperiod (100 μmol m - 2 s - 1) were fed at the apex with mevastatin and then exposed to an UV-B dose administrated at two intensities: low UV-B (8.25 μW cm - 2,16 h) or high UV-B (33 μW cm - 2,4 h). Methanol: chloroform extracts were analyzed by GC-EIMS and compared with controls without mevastatin. Levels of γ-Sitosterol and Stigmasterol were significantly increased under low intensity UV-B in the controls. The plants treated with the inhibitor showed a significant decrease of both sterols and a decrease in the plastidial terpenes but sterols were higher under UV-B. These results suggest an IPP crosstalk between the MAV and MEP pathways under restrictive conditions. (authors)

The effects of different UV-B radiation intensities on morphological and biochemical characteristics in Ocimum basilicum L.

Science.gov (United States)

Sakalauskaitė, Jurga; Viskelis, Pranas; Dambrauskienė, Edita; Sakalauskienė, Sandra; Samuolienė, Giedrė; Brazaitytė, Aušra; Duchovskis, Pavelas; Urbonavičienė, Dalia

2013-04-01

The effects of short-term ultraviolet B (UV-B) irradiation on sweet basil (Ocimum basilicum L. cv. Cinnamon) plants at the 3-4 leaf pair and flowering stages were examined in controlled environment growth chambers. Plants were exposed to 0 (reference), 2 and 4 kJ UV-B m(-2) day(-1) over 7 days. Exposure of basil plants to supplementary UV-B light resulted in increased assimilating leaf area, fresh biomass and dry biomass. Stimulation of physiological functions in young basil plants under either applied UV-B dose resulted in increased total chlorophyll content but no marked variation in carotenoid content. At the flowering stage the chlorophyll and carotenoid contents of basil were affected by supplementary UV-B radiation, decreasing with enhanced UV-B exposure. Both total antioxidant activity (2,2-diphenyl-1-picrylhydrazyl free radical assay) and total phenolic compound content were increased by UV-B light supplementation. Young and mature basil plants differed in their ascorbic acid content, which was dependent on UV-B dose and plant age. UV-B radiation resulted in decreased nitrate content in young basil plants (3-4 leaf pair stage). These results indicate that the application of short-exposure UV-B radiation beneficially influenced both growth parameters and biochemical constituents in young and mature basil plants. © 2012 Society of Chemical Industry.

Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

2011-01-01

, nitrogen and UV-B absorbing compounds. Compared to a 60% reduced UV-B irradiance, the ambient solar UV-B reduced net photosynthesis in Salix arctica leaves fixed in the 45° position which exposed leaves to maximum natural irradiance. Also a reduced Calvin Cycle capacity was found, i.e. the maximum rate...... across position in the vegetation. These findings add to the evidence that the ambient solar UV-B currently is a significant stress factor for plants in high Arctic Greenland....

Cell-type-specific roles for COX-2 in UVB-induced skin cancer

Science.gov (United States)

Herschman, Harvey

2014-01-01

In human tumors, and in mouse models, cyclooxygenase-2 (COX-2) levels are frequently correlated with tumor development/burden. In addition to intrinsic tumor cell expression, COX-2 is often present in fibroblasts, myofibroblasts and endothelial cells of the tumor microenvironment, and in infiltrating immune cells. Intrinsic cancer cell COX-2 expression is postulated as only one of many sources for prostanoids required for tumor promotion/progression. Although both COX-2 inhibition and global Cox-2 gene deletion ameliorate ultraviolet B (UVB)-induced SKH-1 mouse skin tumorigenesis, neither manipulation can elucidate the cell type(s) in which COX-2 expression is required for tumorigenesis; both eliminate COX-2 activity in all cells. To address this question, we created Cox-2 flox/flox mice, in which the Cox-2 gene can be eliminated in a cell-type-specific fashion by targeted Cre recombinase expression. Cox-2 deletion in skin epithelial cells of SKH-1 Cox-2 flox/flox;K14Cre + mice resulted, following UVB irradiation, in reduced skin hyperplasia and increased apoptosis. Targeted epithelial cell Cox-2 deletion also resulted in reduced tumor incidence, frequency, size and proliferation rate, altered tumor cell differentiation and reduced tumor vascularization. Moreover, Cox-2 flox/flox;K14Cre + papillomas did not progress to squamous cell carcinomas. In contrast, Cox-2 deletion in SKH-1 Cox-2 flox/flox; LysMCre + myeloid cells had no effect on UVB tumor induction. We conclude that (i) intrinsic epithelial COX-2 activity plays a major role in UVB-induced skin cancer, (ii) macrophage/myeloid COX-2 plays no role in UVB-induced skin cancer and (iii) either there may be another COX-2-dependent prostanoid source(s) that drives UVB skin tumor induction or there may exist a COX-2-independent pathway(s) to UVB-induced skin cancer. PMID:24469308

UVB suscetibilidade como fator de risco para o desenvolvimento da hanseníase virchowiana UVB susceptibility as a risk factor to the development of lepromatous leprosy

Directory of Open Access Journals (Sweden)

Mecciene Mendes Rodrigues

2010-12-01

Full Text Available FUNDAMENTOS: A radiação ultravioleta B (RUVB é o mais importante fator ambiental capaz de modificar a função imunológica da pele humana. OBJETIVO: estudar a associação entre o fenótipo de suscetibilidade ou resistência à radiação RUVB e as formas polares da hanseníase. MATERIAL E MÉTODOS: foram avaliados 38 pacientes com hanseníase virchowiana (MHV e 87 pacientes com hanseníase tuberculoide (MHT de acordo com a classificação de Ridley e Jopling (1966. Todos os pacientes foram submetidos ao teste para determinação do fenótipo de suscetibilidade ou resistência à RUVB por meio da aplicação de um disco de dinitroclorobenzeno (DNCB a 2% em uma área de pele previamente irradiada com duas vezes a dose eritematosa mínima (DEM. Após 21 dias, outra aplicação de um disco similar de DNCB a 0,05% na região escapular (área não exposta à RUVB foi realizada para avaliar se houve sensibilização, com leitura após 48 horas. Os pacientes que apresentaram reação positiva ao DNCB foram considerados UVB-resistentes e o oposto foi considerado para aqueles que não apresentaram resposta (UVB-suscetíveis. RESULTADOS: A frequência de UVB-suscetíveis foi de 63,2% (24 pacientes no grupo MHV e 34,4% (30 pacientes no grupo MHT (OR = 3,26; IC = 1,36-7,87; x² = 7,73; p = 0,005. CONCLUSÃO: Os resultados sugerem que a UVB-suscetibilidade é um fator de risco para o desenvolvimento da MHV.BACKGROUNDS: Ultraviolet radiation B (UVRB is the most important environmental factor capable of altering the immune function of human skin. OBJECTIVE: To evaluate the association of the phenotypes of susceptibility or resistance to ultraviolet radiation B (UVRB and the polar forms of leprosy. MATERIAL AND METHODS: We evaluated 38 patients with lepromatous leprosy (LL and 87 patients with tuberculoid (TT leprosy, according to the classification by Ridley and Jopling (1966. All the patients were submitted to a test to determine the phenotypes of

Protective effect of 4-coumaric acid from UVB ray damage in the rabbit eye

International Nuclear Information System (INIS)

Lodovici, Maura; Caldini, Silvia; Morbidelli, Lucia; Akpan, Victor; Ziche, Marina; Dolara, Piero

2009-01-01

UV-induced oxidation damage seems to play a major role in a number of specific pathological conditions of intraocular tissues, such as cataract formation and retinal degeneration. Therefore, antioxidant and/or scavenger compounds might protect the eyes from UV-induced cellular damage. We previously reported that 4-coumaric acid (4-CA) is able to protect rabbit corneal-derived cells (SIRC) from UVB-induced oxidation damage. In this study we evaluated the protective effect of 4-CA against UVB-induced cell damage in rabbit cornea in vivo. Twelve male New Zealand albino rabbits were used; four rabbits were used as a control and received vehicle in one eye and 4-CA acid in the contralateral eye; eight rabbits were exposed to UVB rays (79.2 mJ/cm 2 ) and three days before to UV exposure each animal received 1 drop/day of vehicle in one eye and 1 drop/day of vehicle containing 4-CA (164 ng) in the contralateral eye. Corneal and sclera tissues were removed and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) levels were measured. Superoxide dismutase (SOD) and xanthine oxidase (XO) activities were determined in aqueous humour. UVB-induced vessel hyper-reactivity was strongly reduced at 4 and 24 h after UVB exposure after local treatment with 4-CA, 8-oxodGuo levels, a marker of oxidative DNA damage, were significantly increased (P < 0.05) in sclera and cornea by UVB irradiation, but when 4-CA was administered to the conjunctiva in a buffered solution once a day for 3 d before and 6 d after UVB exposure, levels of 8-oxodGuo were similar to controls and significantly reduced (P < 0.05) compared to UVB-treated corneas. XO activity in the aqueous humour was significantly increased. The administration of 4-CA for 3 d before and 6 d after UVB irradiation induced a small but significant (P < 0.05) reduction of XO compared with control eyes. Our results indicate that the administration of 4-CA protects eye tissues, thus reducing the harmful effect of UVB radiation at low

DHU1 negatively regulates UV-B signaling via its direct interaction with COP1 and RUP1.

Science.gov (United States)

Kim, Sang-Hoon; Kim, Hani; Chung, Sunglan; Lee, Jae-Hoon

2017-09-16

Although DWD HYPERSENSITIVE TO UV-B 1 (DHU1) is reported to be a negative regulator in UV-B mediated cellular responses, its detailed role in UV-B signaling is still elusive. To further understand the action mechanism of DHU1 in UV-B response, physical and genetic interactions of DHU1 with various UV-B signaling components were investigated. Yeast two hybrid assay results suggested that DHU1 directly interacts with COP1 and RUP1, implying a functional connection with both COP1 and RUP1. In spite of the physical association between DHU1 and COP1, loss of DHU1 did not affect protein stability of COP1. Epistatic analysis showed that the functional loss of both DHU1 and UVR8 leads to alleviation of UV-B hypersensitivity displayed in dhu1-1. Moreover, phenotypic studies with dhu1-1 cop1-6 and dhu1-1 hy5-215 revealed that COP1 and HY5 are epistatic to DHU1, indicating that UV-B hypersensitivity of dhu1-1 requires both COP1 and HY5. In the case of dhu1-1 rup1-1, UV-B responsiveness was similar to that of both dhu1-1 and rup1-1, implying that DHU1 and RUP1 are required for each other's function. Collectively, these results show that the role of DHU1 as a negative regulator in UV-B response may be derived from its direct interaction with COP1 by sequestering COP1 from the active UVR8-COP1 complex, resulting in a decrease in the COP1 population that positively participates in UV-B signaling together with UVR8. Furthermore, this inhibitory role of DHU1 in UV-B signaling is likely to be functionally connected to RUP1. This study will serve as a platform to further understand more detailed action mechanism of DHU1 in UV-B response and DHU1-mediated core UV-B signaling in Arabidopsis. Copyright © 2017 Elsevier Inc. All rights reserved.

Different levels of UV-B resistance in Vaccinium corymbosum cultivars reveal distinct backgrounds of phenylpropanoid metabolites.

Science.gov (United States)

Luengo Escobar, Ana; Magnum de Oliveira Silva, Franklin; Acevedo, Patricio; Nunes-Nesi, Adriano; Alberdi, Miren; Reyes-Díaz, Marjorie

2017-09-01

UV-B radiation induces several physiological and biochemical effects that can influence regulatory plant processes. Vaccinium corymbosum responds differently to UV-B radiation depending on the UV-B resistance of cultivars, according to their physiological and biochemical features. In this work, the effect of two levels of UV-B radiation during long-term exposure on the phenylpropanoid biosynthesis, and the expression of genes associated with flavonoid biosynthesis as well as the absolute quantification of secondary metabolites were studied in two contrasting UV-B-resistant cultivars (Legacy, resistant and Bluegold, sensitive). Multivariate analyses were performed to understand the role of phenylpropanoids in UV-B defense mechanisms. The amount of phenylpropanoid compounds was generally higher in Legacy than in Bluegold. Different expression levels of flavonoid biosynthetic genes for both cultivars were transiently induced, showing that even in longer period of UV-B exposure; plants are still adjusting their phenylpropanoids at the transcription levels. Multivariate analysis in Legacy indicated no significant correlation between gene expression and the levels of the flavonoids and phenolic acids. By contrast, in the Bluegold cultivar higher number of correlations between secondary metabolite and transcript levels was found. Taken together, the results indicated different adjustments between the cultivars for a successful UV-B acclimation. While the sensitive cultivar depends on metabolite adjustments to respond to UV-B exposure, the resistant cultivar also possesses an intrinsically higher antioxidant and UV-B screening capacity. Thus, we conclude that UV-B resistance involves not only metabolite level adjustments during the acclimation period, but also depends on the intrinsic metabolic status of the plant and metabolic features of the phenylpropanoid compounds. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

P1 epigenetic regulation in leaves of high altitude maize landraces: effect of UV-B radiation

Directory of Open Access Journals (Sweden)

Sebastian Pablo Rius

2016-04-01

Full Text Available P1 is a R2R3-MYB transcription factor that regulates the accumulation of a specific group of flavonoids in maize floral tissues, such as flavones and phlobaphenes. P1 is also highly expressed in leaves of maize landraces adapted to high altitudes and higher levels of UV-B radiation. In this work, we analyzed the epigenetic regulation of the P1 gene by UV-B in leaves of different maize landraces. Our results demonstrate that DNA methylation in the P1 proximal promoter, intron1 and intron2 is decreased by UV-B in all lines analyzed; however, the basal DNA methylation levels are lower in the landraces than in B73, a low altitude inbred line. DNA demethylation by UV-B is accompanied by a decrease in H3 methylation at Lys 9 and 27, and by an increase in H3 acetylation. smRNAs complementary to specific regions of the proximal promoter and of intron 2 3' end are also decreased by UV-B; interestingly, P1 smRNA levels are lower in the landraces than in B73 both under control conditions and after UV-B exposure, suggesting that smRNAs regulate P1 expression by UV-B in maize leaves. Finally, we investigated if different P1 targets in flower tissues are also regulated by this transcription factor in response to UV-B. Some targets analyzed show an induction in maize landraces in response to UV-B, with higher basal expression levels in the landraces than in B73; however, not all the transcripts analyzed were found to be regulated by UV-B in leaves.

Biochemical and ultrastructural changes in pollen of Zea mays L. grown under enhanced UV-B radiation

International Nuclear Information System (INIS)

Santos, A.; Almeida, J.M.; Santos, I.; Salema, R.

1998-01-01

The influence of ultraviolet-B (UV-B) radiation on the development of the male gametophyte was studied in Zea mays L. cv. LG12 grown in a growth chamber under PAR light supplemented with UV-B radiation and compared with a second set of plants grown under PAR light. Pollen samples collected from both groups of plants were cultured on germination medium and it was found that UV-B had no effect on pollen germination. Total pollen protein content was not affected but UV-B absorbing pigments increased. Some ultrastructural alterations were observed in pollen and pollen tubes, in particular large amounts of electron dense deposits were seen throughout the cytoplasm and in association with the pollen wall. In mature spikes of UV-B treated plants, anthers retained numerous pollen grains in their loculi while anthers of control plants were almost empty. UV-B treatment delayed flowering by 2±3 d. These results show that UV-B treatment of maize plants interferes with flowering, pollen ultrastructure and anther maturation even though pollen germination is unaffected. The significant increase of UV-B absorbing pigments in pollen grains could represent a defence mechanism that enables plants to complete their reproductive cycle. (author)

Ambient UV-B radiation decreases photosynthesis in high arctic Vaccinium uliginosum.

OpenAIRE

Albert, Kristian; Ro-Poulsen, Helge; N. Mikkelsen, Teis

2008-01-01

UV-B-exclusion experiment was established in high arctic Zackenberg, Northeast Greenland, to investigate the possible effects of ambient UV-B on plant performance. During almost a whole growing season, canopy gas exchange and Chl fluorescence were measured on Vaccinium uliginosum (bog blueberry). Leaf area, biomass, carbon, nitrogen and UV-B-absorbing compounds were determined from a late season harvest. Compared with the reduced UV-B treatment, the plants in ambient UV-B were found to have a...

The evolutionary response of plants to increased UV-B radiation: Field studies with Arabidopsis thaliana

International Nuclear Information System (INIS)

Trumbull, V.L.; Paige, K.N.

1995-01-01

The response of a species to any environmental change is determined by both phenotypic and evolutionary adjustments. To date, the majority of research concerning the response of terrestrial plants to increased UV-B radiation has focused on phenotypic adjustments. Recently we have initiated field studies aimed at assessing genetic variation for UV-B sensitivity within a natural population of Arabidopsis thaliana. This population consists of at least eight discrete genotypes that have been confirmed by RAPD analysis. We used an incomplete block design to assess the impact of UV-B (ambient and ambient + 6 kJ) and PAR (low and high) on these genotypes. The high UV-B treatment caused a significant reduction in fruit number and plant height while the high PAR treatment caused a significant increase in these variables. In addition, there was a marginally significant (p=0.1) UV-B x PAR x maternal line interaction for fruit number, indicating that genetic variation for UV-B sensitivity within this population depends on the PAR environment. The combination of high UV-B and high PAR caused a change in fruit number (relative to the ambient UV-B/high PAR treatment) ranging from an increase of 24% to a decrease of 47%. This range was much smaller in the low PAR treatment. These results indicate the potential for increased UV-B radiation to act as an agent of natural selection within this population

Differences in the sensitivity to UVB radiation of two cultivars of rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Hidema, J.; Kang, H.S.; Kumagai, T.

1996-01-01

The effects of UVB radiation on the growth of two cultivars of Japanese lowland rice (Oryza sativa L.), Sasanishiki and Norin 1, were examined in a phytotron. Supplementation of visible radiation with UVB radiation reduced plant length, tiller number, the fresh and dry weights of the aboveground parts of plants, an the amounts of total leaf nitrogen, chlorophyll, soluble protein and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the eight leaf, the youngest fully expanded leaf. By contrast, UVB radiation significantly increased the accumulation of UV-absorbing compounds. There was a difference between the two cultivars in the resistance to the effects of UVB radiation. The reduction in the amounts of Rubisco was smaller in Sasanishiki, while the increase in the accumulation of UV-absorbing compounds was greater in Sasanishiki. Parameters of plant growth, with the exception of the amount of Rubisco, decreased in direct proportion to decreases in total leaf nitrogen in plants grown under lower or the Rubisco content of Norin 1 grown under a high dose of UVB radiation was exceptionally marked, and was not observed similarly in Sasanishiki. The results suggest that the remarkable reduction in rubisco content in NOrin 1 might have been due to the specific effects of UVB radiation. It is also suggested that the difference between cultivars in the resistance to UVB radiation might be due to the differences in the levels of Rubisco and in UV-absorbing compounds that are induced by UVB radiation

UV-B effect on constituents of Azolla caroliniana.

Science.gov (United States)

Ibrahim, Mohamed M; Mostafa, Eazaz M

2007-01-01

Changes in growth and ultrastructure of Azolla caroliniana in response to elevated UV-B radiation were investigated. Exposure of plants to UV-B radiation for 1, 8, 16, 24 and 48 h exhibited a significant decrease in biomass and relative growth rate. This decrease resulted in an increase in doubling time over the control. Also, Chl a and b contents were significantly decreased especially after 16 h. The reduction was accompanied by a decrease in 5-aminolaevulinic acid content (precursor of chlorophyll). On the other hand, contents of carotenoid and UV-absorbing phenolic compounds (flavonoids and anthocyanins) were increased.

Stratospheric ozone depletion: high arctic tundra plant species from Svalbard are not affected by enhanced UV-B after 7 years of UV-B supplementation in the field.

NARCIS (Netherlands)

Rozema, J.; Boelen, P.; Blokker, P.; Callaghan, T.V.; Solheim, B.; Zielke, M.

2006-01-01

The response of tundra plants to enhanced UV-B radiation simulating 15 and 30% ozone depletion was studied at two high arctic sites (Isdammen and Adventdalen, 78° N, Svalbard).The set-up of the UV-B supplementation systems is described, consisting of large and small UV lamp arrays, installed in 1996

An action spectrum for UV-B radiation and the rat lens.

Science.gov (United States)

Merriam, J C; Löfgren, S; Michael, R; Söderberg, P; Dillon, J; Zheng, L; Ayala, M

2000-08-01

To determine an action spectrum for UV-B radiation and the rat lens and to show the effect of the atmosphere and the cornea on the action spectrum. One eye of young female rats was exposed to 5-nm bandwidths of UV-B radiation (290, 295, 300, 305, 310, and 315 nm). Light scattering of exposed and nonexposed lenses was measured 1 week after irradiation. A quadratic polynomial was fit to the dose-response curve for each wave band. The dose at each wave band that produced a level of light scattering greater than 95% of the nonexposed lenses was defined as the maximum acceptable dose (MAD). Transmittance of the rat cornea was measured with a fiberoptic spectrophotometer. The times to be exposed to the MAD in Stockholm (59.3 degrees N) and La Palma (28 degrees N) were compared. Significant light scattering was detected after UV-B at 295, 300, 305, 310, and 315 nm. The lens was most sensitive to UV-B at 300 nm. Correcting for corneal transmittance showed that the rat lens is at least as sensitive to UV radiation at 295 nm as at 300 nm. The times to be exposed to the MAD at each wave band were greater in Stockholm than in La Palma, and in both locations the theoretical time to be exposed to the MAD was least at 305 nm. After correcting for corneal transmittance, the biological sensitivity of the rat lens to UV-B is at least as great at 295 nm as at 300 nm. After correcting for transmittance by the atmosphere, UV-B at 305 nm is the most likely wave band to injure the rat lens in both Stockholm and La Palma.

Skin pigmentation kinetics after UVB exposure

DEFF Research Database (Denmark)

Ravnbak, M.H.; Philipsen, P.A.; Wiegell, S.R.

2008-01-01

There have been few previous studies of the kinetics of pigmentation following ultraviolet B (UVB) exposure, and these have included only fair-skinned persons. The current study investigated pigmentation increase to steady state and fading in 12 Scandinavians and 12 Indians/Pakistanis. Over...... a period of 3 weeks the subjects were UV-irradiated 6 times on the right side of the back and 12 times on the left side using a Solar Simulator and narrowband UVB with equal sub-Minimal Melanogenesis Doses (individually predetermined). Pigmentation was measured from skin remittance at 555 urn and 660 nm...... (allowing correction for erythema). The absolute pigmentation increase was independent of pre-exposure pigmentation, therefore the percentage pigmentation increase was higher in fair-skinned volunteers. The UV dose to minimal pigmentation was higher in darker-skinned persons for single and multiple UV...

Alleviation of UV-B stress in Arabidopsis using tea catechins | Lee ...

African Journals Online (AJOL)

Ultraviolet-B (UV-B) has been confirmed to be harmful to living organisms and it is of concern that the amount of UV-B radiation reaching the earth's surface is increasing because of the depletion of the stratospheric ozone layer. Effect of different levels of tea catechins on morphological damage and expression of chalcone ...

Differential flavonoid response to enhanced UV-B radiation in Brassica napus

International Nuclear Information System (INIS)

Olsson, L.C.; Veit, M.; Weissenböck, G.; Bornman, J.F.

1998-01-01

We have examined the qualitative and quantitative differences in methanol-soluble flavonoids of leaves of two cultivars of Brassica napus, which were grown with or without (control) supplemental UV-B radiation. The flavonoids were identified using HPLC-diode array spectroscopy (-DAS), -electrospray ionization-mass spectroscopy (-ESI-MS) and 1H and 13C NMR, and quantitatively analysed by HPLC-DAS. After exposure to supplementary UV-B radiation, the overall amount of soluble flavonoids, kaempferol and quercetin glycosides, increased by ca 150% in cv. Paroll, compared to control plants. Cultivar Stallion showed a 70% increase, and also a lower overall content of soluble flavonoids compared to Paroll. The supplementary UV-B radiation resulted in a marked, specific increase in the amount of quercetin glycosides relative to the kaempferol glycosides with a 36- and 23-fold increase in cvs Paroll and Stallion, respectively. Four of the flavonol glycosides appearing after supplemental UV-B exposure were identified as quercetin- and kaempferol 3-sophoroside-7-glucoside and 3-(2″′-E-sinapoylsophoroside)-7-glucoside. (author)

Mitochondria-Targeted Vitamin E Protects Skin from UVB-Irradiation.

Science.gov (United States)

Kim, Won-Serk; Kim, Ikyon; Kim, Wang-Kyun; Choi, Ju-Yeon; Kim, Doo Yeong; Moon, Sung-Guk; Min, Hyung-Keun; Song, Min-Kyu; Sung, Jong-Hyuk

2016-05-01

Mitochondria-targeted vitamin E (MVE) is designed to accumulate within mitochondria and is applied to decrease mitochondrial oxidative damage. However, the protective effects of MVE in skin cells have not been identified. We investigated the protective effect of MVE against UVB in dermal fibroblasts and immortalized human keratinocyte cell line (HaCaT). In addition, we studied the wound-healing effect of MVE in animal models. We found that MVE increased the proliferation and survival of fibroblasts at low concentration (i.e., nM ranges). In addition, MVE increased collagen production and downregulated matrix metalloproteinase1. MVE also increased the proliferation and survival of HaCaT cells. UVB increased reactive oxygen species (ROS) production in fibroblasts and HaCaT cells, while MVE decreased ROS production at low concentration. In an animal experiment, MVE accelerated wound healing from laser-induced skin damage. These results collectively suggest that low dose MVE protects skin from UVB irradiation. Therefore, MVE can be developed as a cosmetic raw material.

Response of oxidative stress defense systems in rice (Oryza sativa) leaves with supplemental UV-B radiation

International Nuclear Information System (INIS)

Dai, Q.; Yan, B.; Huang, S.; Liu, X.; Peng, S.; Miranda, M.L.L.; Chavez, A.Q.; Vergara, B.S.; Olszyk, D.M.

1997-01-01

The impact of elevated ultraviolet-B radiation (UV-B, 280–320 nm) on membrane systems and lipid peroxidation, and possible involvement of active oxygen radicals was investigated in leaves of two UV-B susceptible rice cultivars (Oryza sativa L. cvs IR74 and Dular). Rice seedlings were grown in a greenhouse for 10 days and then treated with biologically effective UV-B (UV-B BE ) radiation for 28 days. Oxidative stress effects were evaluated by measuring superoxide anion (O 2 ) generation rate, hydrogen peroxide (H 2 O 2 ) content, malondialdehyde (MDA) concentration and relative electrolyte conductivity (EC) for IR74 and Dular at 0 (control), 6 or 13 kJ m −2 day −1 UV-B BE . Significant increases in these parameters were found in rice plants grown at 13 vs 0 kJ m −2 day −1 UV-B BE after 28 days; indicating that disruption of membrane systems may be an eventual reason for UV-B-induced injury in rice plants. There was a positive correlation between O 2 − generation and increases in EC or MDA in leaves. Activities of enzymatic and nonenzymatic free radical scavengers were measured for IR74 after 7, 14, 21 and 28 days of exposure to 13 or 0 UV-B BE to evaluate dynamics of these responses over time. Activities of catalase and superoxide dismutase (but not ascorbate peroxidase) and concentrations of ascorbic acid and glutathione were enhanced by 13 vs 0 UV-B BE after 14 days of UV-B exposure. Further exposure to 28 days of UV-B was associated with a decline in enzyme activities and ascorbic acid, but not glutathione. It is suggested that UV-B-induced injury may be associated with disturbance of active oxygen metabolism through the destruction and alteration of both enzymatic and nonenzymatic defense systems in rice. (author)

Effects of UV-B irradiation on growth, survival, pigmentation and nitrogen metabolism enzymes in Cyanobacteria

Energy Technology Data Exchange (ETDEWEB)

Sinha, R.P.; Hader, D.P. [Institut fuer Botanik und Pharmazeutische Biologie, Friedrich-Alexander Universitaet, Erlangen (Germany); Kumar, H.D.; Kumar, A. [Banaras Hindu University, Varanasi (India)

1995-12-31

The effects of artificial UV-B irradiation on growth, survival, pigmentation, nitrate reductase (NR), glutamine synthetase (GS) and total protein profile have been studied in a number of N{sub 2}-fixing cyanobacterial strains isolated from rice (paddy) fields in India. Different organisms show different effects in terms of growth and survival. Complete killing of Anabaena sp. and Nostoc carmium occurs after 120 min of UV-B exposure, whereas the same occurs only after 150 min of exposure in the case of Nostoc commune and Scytonema sp. Growth patterns of the cells treated with UV-B revealed that Nostoc commune and Scytonema sp. are comparatively more tolerant than Anabaena sp. and Nostoc carmium. Pigment content, particularly phycocyanin, was severely decreased following UV-B irradiation in all strains tested so far. In vivo NR activity was found to increase, while in vivo GS activity was decreased following exposure to UV-B for different durations in all test organisms; although complete inhibition of GS activity did not occur even after 120 min of UV-B exposure. (author). 37 refs, 6 figs.

Effects of UV-B irradiation on growth, survival, pigmentation and nitrogen metabolism enzymes in Cyanobacteria

International Nuclear Information System (INIS)

Sinha, R.P.; Hader, D.P.; Kumar, H.D.; Kumar, A.

1995-01-01

The effects of artificial UV-B irradiation on growth, survival, pigmentation, nitrate reductase (NR), glutamine synthetase (GS) and total protein profile have been studied in a number of N 2 -fixing cyanobacterial strains isolated from rice (paddy) fields in India. Different organisms show different effects in terms of growth and survival. Complete killing of Anabaena sp. and Nostoc carmium occurs after 120 min of UV-B exposure, whereas the same occurs only after 150 min of exposure in the case of Nostoc commune and Scytonema sp. Growth patterns of the cells treated with UV-B revealed that Nostoc commune and Scytonema sp. are comparatively more tolerant than Anabaena sp. and Nostoc carmium. Pigment content, particularly phycocyanin, was severely decreased following UV-B irradiation in all strains tested so far. In vivo NR activity was found to increase, while in vivo GS activity was decreased following exposure to UV-B for different durations in all test organisms; although complete inhibition of GS activity did not occur even after 120 min of UV-B exposure. (author)

UVB-induced gene expression in the skin of Xiphophorus maculatus Jp 163 B☆

Science.gov (United States)

Yang, Kuan; Boswell, Mikki; Walter, Dylan J.; Downs, Kevin P.; Gaston-Pravia, Kimberly; Garcia, Tzintzuni; Shen, Yingjia; Mitchell, David L.; Walter, Ronald B.

2014-01-01

Xiphophorus fish and interspecies hybrids represent long-standing models to study the genetics underlying spontaneous and induced tumorigenesis. The recent release of the Xiphophorus maculatus genome sequence will allow global genetic regulation studies of genes involved in the inherited susceptibility to UVB-induced melanoma within select backcross hybrids. As a first step toward this goal, we report results of an RNA-Seq approach to identify genes and pathways showing modulated transcription within the skin of X. maculatus Jp 163 B upon UVB exposure. X. maculatus Jp 163 B were exposed to various doses of UVB followed by RNA-Seq analysis at each dose to investigate overall gene expression in each sample. A total of 357 genes with a minimum expression change of 4-fold (p-adj fish skin to UVB exposure. PMID:24556253

Effects of different levels of UV-B radiation on marine epilithic communities: a short-term microcosm study

Directory of Open Access Journals (Sweden)

R. A. Danilov

2000-12-01

Full Text Available Epilithic communities from brackish coastal water of the east coast of Sweden were studied in order to reveal their responses to different levels of UV-B radiation. The experiment was conducted for seven days in an indoor microcosm system. The epilithic communities were exposed daily to different doses of UV-B radiation: 1, 3, 5 and 7 hours, respectively. The intensity of the UV-B radiation used was similar to that in natural environments. After seven days clear shifts both in species composition and community structure were observed. All species of diatoms showed negative correlation with enhanced levels of UV-B. On the other hand, abundance of cyanobacteria was positively correlated with enhanced levels of UV-B (Calothrix aeruginea, R=0.49;Oscillatoria amphibia, R=0.93; Pseudanabaena mucicola, R=0.26. Communities dominated by diatoms and green algae at the initial stage of the experiment did show a drastic decrease in diatom abundance under UV-B stress and finally became dominated by cyanobacteria. Among green algae the abundance of Cladophora sericea correlated positively (R=0.33 with enhanced exposure to UV-B, while Monoraphidium-species exhibited negative correlation to UV-B. Otherwise, no significant correlation between other green algae species identified and UV-B stress could be detected. We conclude that UV-B radiation, even at lower levels, is capable to induce severe changes to marine epilithic communities. The trends revealed in the present study predict a shift from communities dominated by diatoms and green algae to those dominated by cyanobacteria.

Influence of uvA on the erythematogenic and therapeutic effects of uvB irradiation in psoriasis; photoaugmentation effects

International Nuclear Information System (INIS)

Boer, J.; Schothorst, A.A.; Suurmond, D.

1981-01-01

The effect of repeated exposure to an additive dose of long ultraviolet (uvA) radiation on the erythemogenic and therapeutic effects of middle ultraviolet (uvB) irradiation was investigated in 8 patients with psoriasis. The surface of the backs of these patients was divided into 2 parts, 1 of which received only uvB irradiation 4 times a week and the other uvA + uvB. uvB was provided by Philips TL-12 lamps and uvA by glass-filtered Philips TL-09 lamps. uvA was held constantly at 10 J/cm2, whereas uvB alone were evaluated by 4 tests during the treatment to determine the minimal erythema dose (MED). Test I (at the start of the therapy) showed a photoaugmentative effect which was no longer apparent in Test III (third week). Test III showed a reversal of the ratios of the MEDs of the sites irradiated with the uvA + uvB and uvB (MED A + B/MED B). This is ascribed to the marked pigmentation which appeared after repeated irradiation with the uvA + uvB combination. Comparison showed for the improvement of the psoriasis no distinct differences between uvA + uvB irradiation and uvB alone, but the former had the cosmetic advantage of giving pleasing tan

Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams.

Science.gov (United States)

Takano, Nao; Takahashi, Yuko; Yamamoto, Mitsuru; Teranishi, Mika; Yamaguchi, Hiroko; Sakamoto, Ayako N; Hase, Yoshihiro; Fujisawa, Hiroko; Wu, Jianzhong; Matsumoto, Takashi; Toki, Seiichi; Hidema, Jun

2013-07-01

UVB radiation suppresses photosynthesis and protein biosynthesis in plants, which in turn decreases growth and productivity. Here, an ultraviolet-B (UVB)-tolerant rice mutant, utr319 (UV Tolerant Rice 319), was isolated from a mutagenized population derived from 2500 M1 seeds (of the UVB-resistant cultivar 'Sasanishiki') that were exposed to carbon ions. The utr319 mutant was more tolerant to UVB than the wild type. Neither the levels of UVB-induced cyclobutane pyrimidine dimers (CPDs) or (6-4) pyrimidine-pyrimidone photodimers [(6-4) photoproducts], nor the repair of CPDs or (6-4) photoproducts, was altered in the utr319 mutant. Thus, the utr319 mutant may be impaired in the production of a previously unidentified factor that confers UVB tolerance. To identify the mutated region in the utr319 mutant, microarray-based comparative genomic hybridization analysis was performed. Two adjacent genes on chromosome 7, Os07g0264900 and Os07g0265100, were predicted to represent the mutant allele. Sequence analysis of the chromosome region in utr319 revealed a deletion of 45 419 bp. RNAi analysis indicated that Os07g0265100 is most likely the mutated gene. Database analysis indicated that the Os07g0265100 gene, UTR319, encodes a putative protein with unknown characteristics or function. In addition, the homologs of UTR319 are conserved only among land plants. Therefore, utr319 is a novel UVB-tolerant rice mutant and UTR319 may be crucial for the determination of UVB sensitivity in rice, although the function of UTR319 has not yet been determined.

Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams

International Nuclear Information System (INIS)

Takano, Nao; Takahashi, Yuko; Yamamoto, Mitsuru; Teranishi, Mika; Yamaguchi, Hiroko; Sakamoto, Ayako N.; Hase, Yoshihiro; Fujisawa, Hiroko; Wu, Jianzhong; Matsumoto, Takashi; Toki, Seiichi; Hidema, Jun

2013-01-01

UVB radiation suppresses photosynthesis and protein biosynthesis in plants, which in turn decreases growth and productivity. Here, an ultraviolet-B (UVB)-tolerant rice mutant, utr319 (UVTolerantRice319), was isolated from a mutagenized population derived from 2500 M 1 seeds (of the UVB-resistant cultivar ‘Sasanishiki’) that were exposed to carbon ions. The utr319 mutant was more tolerant to UVB than the wild type. Neither the levels of UVB-induced cyclobutane pyrimidine dimers (CPDs) or (6-4) pyrimidine-pyrimidone photodimers [(6-4) photoproducts], nor the repair of CPDs or (6-4) photoproducts, was altered in the utr319 mutant. Thus, the utr319 mutant may be impaired in the production of a previously unidentified factor that confers UVB tolerance. To identify the mutated region in the utr319 mutant, microarray-based comparative genomic hybridization analysis was performed. Two adjacent genes on chromosome 7, Os07g0264900 and Os07g0265100, were predicted to represent the mutant allele. Sequence analysis of the chromosome region in utr319 revealed a deletion of 45 419 bp. RNAi analysis indicated that Os07g0265100 is most likely the mutated gene. Database analysis indicated that the Os07g0265100 gene, UTR319, encodes a putative protein with unknown characteristics or function. In addition, the homologs of UTR319 are conserved only among land plants. Therefore, utr319 is a novel UVB-tolerant rice mutant and UTR319 may be crucial for the determination of UVB sensitivity in rice, although the function of UTR319 has not yet been determined

Silicon nanoparticles more effectively alleviated UV-B stress than silicon in wheat (Triticum aestivum) seedlings.

Science.gov (United States)

Tripathi, Durgesh Kumar; Singh, Swati; Singh, Vijay Pratap; Prasad, Sheo Mohan; Dubey, Nawal Kishore; Chauhan, Devendra Kumar

2017-01-01

The role of silicon (Si) in alleviating biotic as well as abiotic stresses is well known. However, the potential of silicon nanoparticle (SiNP) in regulating abiotic stress and associated mechanisms have not yet been explored. Therefore, in the present study hydroponic experiments were conducted to investigate whether Si or SiNp are more effective in the regulation of UV-B stress. UV-B (ambient and enhanced) radiation caused adverse effect on growth of wheat (Triticum aestivum) seedlings, which was accompanied by declined photosynthetic performance and altered vital leaf structures. Levels of superoxide radical and H 2 O 2 were enhanced by UV-B as also evident from their histochemical stainings, which was accompanied by increased lipid peroxidation (LPO) and electrolyte leakage. Activities of superoxide dismutase and ascorbate peroxidase were inhibited by UV-B while catalase and guaiacol peroxidase, and all non-enzymatic antioxidants were stimulated by UV-B. Although, nitric oxide (NO) content was increased at all tested combinations, but its maximum content was observed under SiNps together with UV-B enhanced treatment. Pre-additions of SiNp as well as Si protected wheat seedlings against UV-B by regulating oxidative stress through enhanced antioxidants. Data indicate that SiNp might have protected wheat seedlings through NO-mediated triggering of antioxidant defense system, which subsequently counterbalance reactive oxygen species-induced damage to photosynthesis. Further, SiNp appear to be more effective in reducing UV-B stress than Si, which is related to its greater availability to wheat seedlings. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

How narrow-band and broad-band uvb irradiation influences the immunohistochemistry analyses of experimental animals’ skin – a comparative study. Part II

Directory of Open Access Journals (Sweden)

Katarzyna Borowska

2017-09-01

Full Text Available This is the second part of the artcle series impact narrow-band UVB radiation (NB-UVB and broad-band UVB radiation (BB-UVB on experimental animals’ skin (white Wistar female rats. The aim of this comparative study was immunohistochemistry analyses containing expression of p53 protein. Expression of p53 protein was performed on two experimental groups. One – exposed to NB-UVB; the other – exposed to BB-UVB radiation. The results indicate that p53 protein takes an active part in the process of apoptosis that is induced by both NB-UVB and BB-UVB. The results showed an increase in p53 expressing cells following BB-UVB than NB-UVB phototherapy.

Antagonist effects of veratric acid against UVB-induced cell damages.

Science.gov (United States)

Shin, Seoung Woo; Jung, Eunsun; Kim, Seungbeom; Lee, Kyung-Eun; Youm, Jong-Kyung; Park, Deokhoon

2013-05-10

Ultraviolet (UV) radiation induces DNA damage, oxidative stress, and inflammatory processes in human epidermis, resulting in inflammation, photoaging, and photocarcinogenesis. Adequate protection of skin against the harmful effect of UV irradiation is essential. In recent years naturally occurring herbal compounds such as phenolic acids, flavonoids, and high molecular weight polyphenols have gained considerable attention as beneficial protective agents. The simple phenolic veratric acid (VA, 3,4-dimethoxybenzoic acid) is one of the major benzoic acid derivatives from vegetables and fruits and it also occurs naturally in medicinal mushrooms which have been reported to have anti-inflammatory and anti-oxidant activities. However, it has rarely been applied in skin care. This study, therefore, aimed to explore the possible roles of veratric acid in protection against UVB-induced damage in HaCaT cells. Results showed that veratric acid can attenuate cyclobutane pyrimidine dimers (CPDs) formation, glutathione (GSH) depletion and apoptosis induced by UVB. Furthermore, veratric acid had inhibitory effects on the UVB-induced release of the inflammatory mediators such as IL-6 and prostaglandin-E2. We also confirmed the safety and clinical efficacy of veratric acid on human skin. Overall, results demonstrated significant benefits of veratric acid on the protection of keratinocyte against UVB-induced injuries and suggested its potential use in skin photoprotection.

Effects of UV-B irradiation on photomovement in the desmid, Cosmarium cucumis

International Nuclear Information System (INIS)

Haeder, D.-P.

1987-01-01

Monochromatic UV-B irradiation affects neither the absorption nor the fluorescence of the bulk pigments in the desmid Cosmarium cucumis but it impairs photomovement of these organisms at fluence rates which are not higher than the ambient level of solar UV-B irradiation. Photoaccumulations and phototaxis are strongly inhibited especially at wavelengths <= 300 nm while photodispersal at higher white light fluence rates is hardly affected by supplementary UV-B. This effect has important consequences for the growth and survival of populations in their natural environment: these photosynthetic organisms utilize photomovement to find and stay in areas of suitable visible light fluence rates. The UV-B component of solar irradiation both impairs the strategy of the organisms to find a suitable position and the escape mechanism by which the cells move out of areas with too strong white illuminances which photooxidize the bulk pigments and bleach the population within a few days. (author)

Influence of water and salt solutions on UVB irradiation of normal skin and psoriasis

International Nuclear Information System (INIS)

Boer, J.; Schothorst, A.A.; Boom, B.; Suurmond, D.; Hermans, J.

1982-01-01

The influence of tap-water (TW) and salt solutions on the minimal erythema dose (MED) was investigated for normal human skin and uninvolved skin of psoriasis patients. MED (UVB) determinations on the forearm revealed that: (1) the MED definitely decreases whenever the arm is immersed in TW or NaCl solutions with a low concentration (4%) prior to UVB exposure, whereas almost saturated NaCl solution (26%), as well as locum Dead Sea water (LDSW), do not produce a change in the MED, and (2) the decrease in MED obtained by wetting the skin with TW was no longer present when the skin was allowed to dry for 20 min. A decrease in water uptake by skin (in vivo) and by callus (in vitro) was found as the salt concentration of the external solution increased. It is proposed that water taken up by the skin plays an important role in the sensitivity of the skin to UVB exposure. Bathing in TW or 4% NaCl prior to UVB exposure offered a slight to moderate improvement in psoriasis over UVB irradiation alone. Finally, it was shown that there is no obvious difference in clearance of the psoriatic skin between a bath in TW, 4% NaCl, or LDSW prior to UVB exposure. (orig.)

Effects of environmental and artificial UV-B radiation on freshwater prawn Macrobrachium olfersi embryos

Energy Technology Data Exchange (ETDEWEB)

Nazari, Evelise Maria [Programa de Pos-Graduacao em Ciencias Morfologicas, Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, 21949-902 Rio de Janeiro, RJ (Brazil); Universidade Federal de Santa Catarina, Departamento de Biologia Celular, Embriologia e Genetica, Campus Universitario, 88040-900 Florianopolis, SC (Brazil); Ammar, Dib [Universidade do Oeste de Santa Catarina, Departamento de Biologia, Campus Universitario, 89600-000 Joacaba, SC (Brazil); Bem, Andreza Fabro de; Latini, Alexandra [Universidade Federal de Santa Catarina, Departamento de Bioquimica, Campus Universitario, 88040-900 Florianopolis, SC (Brazil); Mueller, Yara Maria Rauh [Universidade Federal de Santa Catarina, Departamento de Biologia Celular, Embriologia e Genetica, Campus Universitario, 88040-900 Florianopolis, SC (Brazil); Allodi, Silvana, E-mail: sallodi@histo.ufrj.br [Programa de Pos-Graduacao em Ciencias Morfologicas, Instituto de Ciencias Biomedicas, Universidade Federal do Rio de Janeiro, 21949-902 Rio de Janeiro, RJ (Brazil)

2010-06-01

The recent decrease of the stratospheric ozone has resulted in an increase of ultraviolet-B (UV-B) radiation reaching the Earth's surface. In freshwater ecosystems with transparent water, UV-B rays easily penetrate and potentially cause harmful effects to organisms. In this study, embryos of the prawn Macrobrachium olfersi were used to evaluate the impact of UV-B rays in freshwater environments. We observed three groups of embryos: the first was to assess whether UV-B radiation produced morphological defects and/or biochemical impairments in the laboratory. The second was to check whether embryos with the same impairments as those observed in the laboratory were found in their environment, under natural solar radiation. The third group was the non-irradiated control. The embryos irradiated with 310 mW cm{sup -2} UV-B for 30 min showed morphological alterations similar to those observed in embryos from the environmental control group. The most important effects of the UV-B radiation observed in M. olfersi embryos were morphological (1.2% of the total number of embryos from the environment and 2.8% of the total number of irradiated embryos), pigmentation changes in the eyes (78.0% of the total number of embryos from the environment and 98.9% of the total number of irradiated embryos), and disruption of the chromatophores (46.9% of the total number of embryos from the environment and 95.5% of the total number of irradiated embryos). We also observed an increase in egg volume, which was accompanied by a significant increase in water content in UV-B irradiated groups when compared with aquaria control embryos. In addition, a significant decrease in the mitotic index in eggs exposed to UV-B radiation was detected (0.17 for the embryos from the aquaria control, 0.10 for the embryos of the environmental control, and 0.04 for the irradiated groups). The low levels of NPSH and high levels of TBARS indicated that UV-B rays directly compromised the antioxidant function of

Effects of environmental and artificial UV-B radiation on freshwater prawn Macrobrachium olfersi embryos

International Nuclear Information System (INIS)

Nazari, Evelise Maria; Ammar, Dib; Bem, Andreza Fabro de; Latini, Alexandra; Mueller, Yara Maria Rauh; Allodi, Silvana

2010-01-01

The recent decrease of the stratospheric ozone has resulted in an increase of ultraviolet-B (UV-B) radiation reaching the Earth's surface. In freshwater ecosystems with transparent water, UV-B rays easily penetrate and potentially cause harmful effects to organisms. In this study, embryos of the prawn Macrobrachium olfersi were used to evaluate the impact of UV-B rays in freshwater environments. We observed three groups of embryos: the first was to assess whether UV-B radiation produced morphological defects and/or biochemical impairments in the laboratory. The second was to check whether embryos with the same impairments as those observed in the laboratory were found in their environment, under natural solar radiation. The third group was the non-irradiated control. The embryos irradiated with 310 mW cm -2 UV-B for 30 min showed morphological alterations similar to those observed in embryos from the environmental control group. The most important effects of the UV-B radiation observed in M. olfersi embryos were morphological (1.2% of the total number of embryos from the environment and 2.8% of the total number of irradiated embryos), pigmentation changes in the eyes (78.0% of the total number of embryos from the environment and 98.9% of the total number of irradiated embryos), and disruption of the chromatophores (46.9% of the total number of embryos from the environment and 95.5% of the total number of irradiated embryos). We also observed an increase in egg volume, which was accompanied by a significant increase in water content in UV-B irradiated groups when compared with aquaria control embryos. In addition, a significant decrease in the mitotic index in eggs exposed to UV-B radiation was detected (0.17 for the embryos from the aquaria control, 0.10 for the embryos of the environmental control, and 0.04 for the irradiated groups). The low levels of NPSH and high levels of TBARS indicated that UV-B rays directly compromised the antioxidant function of the

Vitamin D production after UVB exposure - a comparison of exposed skin regions.

Science.gov (United States)

Osmancevic, Amra; Sandström, Katarina; Gillstedt, Martin; Landin-Wilhelmsen, Kerstin; Larkö, Olle; Wennberg Larkö, Ann-Marie; F Holick, Michael; Krogstad, Anne-Lene

2015-02-01

Cholecalciferol is an essential steroid produced in the skin by solar ultraviolet B radiation (UVB 290-315nm). Skin production of cholecalciferol depends on factors affecting UVB flux, age and exposed skin area. Serum cholecalciferol and 25-hydroxyvitamin D3 [25(OH)D3] concentrations were measured after UVB irradiation of 3 different skin areas to compare the skin capacity to produce vitamin D in different anatomic sites in the same individuals. Ten voluntary Caucasians (skin photo type II & III, aged 48±12years (±SD)) were exposed to broadband UVB (280-320nm) between February and April. Hands and face, upper body and whole body were exposed to a suberythemic dose of UVB (median 101mJ/cm(2) (min 66, max 143)) (for 3 subsequent days 24h apart with a wash out period of about 3weeks (median 18days (min 11, max 25)) between the exposures of respective area. Serum concentrations of cholecalciferol and 25(OH)D3, were measured immediately before the first and 24h after the last dose of radiation. There was a significantly higher increase in serum cholecalciferol after UVB exposure of the two larger skin areas compared to face and hands, but no difference in increase was found between upper body and whole body exposures. Exposure of a larger skin area was superior to small areas and gave greater increase in both serum cholecalciferol and serum 25(OH)D3 concentrations. However, exposure of face and hands, i.e. only 5% of the body surface area, was capable of increasing serum concentrations of 25(OH)D3. Copyright © 2015 Elsevier B.V. All rights reserved.

COMPARATIVE ANALYSIS OF UV-C AND UV-B RADIATION INFLUENCE ON PLANT OBJECTS

Directory of Open Access Journals (Sweden)

О. Міхєєв

2011-04-01

Full Text Available General aim of work – comparative research of temporal regularities of growth processes of pea,that was grown under normal conditions and with application of UV-C and UV-B irradiation ofstem part, and also detection of irradiation dose relations to parameter of root and stem part sproutsgrowth rate of Aronis pea. Research subject of UV-C and UV-B irradiation influence on dynamicsof plant growth parameters in each set of experiments was alteration of growth rate, pecularities ofgrowth dynamics in different conditions of experiment, detection of UV-C and UV-B irradiationdoses range, that stimulate or inhibit growth parameters of pea sprouts. The investigation resulted indetermination 1,3 times higher efficiency of UV-V irradiation comparing to UV-B irradiation.Reaction of root didn’t depend on the type of UV-radiation

Inhibitory effects of ambient levels of solar UV-A and UV-B radiation on growth of cucumber

International Nuclear Information System (INIS)

Krizek, D.T.; Mirecki, R.M.; Britz, S.J.

1997-01-01

The influence of solar UV-A and UV-B radiation at Beltsville, Maryland, on growth and flavonoid content in four cultivars of Cucumis sativus L. (Ashley, Poinsett, Marketmore, and Salad Bush cucumber) was examined during the summers of 1994 and 1995. Plants were grown from seed in UV exclusion chambers consisting of UV-transmitting Plexiglas, lined with Llumar to exclude UV-A and UV-B, polyester to exclude UV-B, or cellulose acetate to transmit UV-A and UV-B. Despite previously determined differences in sensitivity to supplemental UV-B radiation, all four cultivars responded similarly to UV-B exclusion treatment. After 19–21 days, the four cultivars grown in the absence of solar UV-B (polyester) had an average of 34, 55, and 40% greater biomass of leaves, stems, and roots, respectively, 27% greater stem height, and 35% greater leaf area than those grown under ambient UV-B (cellulose acetate). Plants protected from UV-A radiation as well (Llumar) showed an additional 14 and 22% average increase, respectively, in biomass of leaves and stems, and a 22 and 19% average increase, respectively, in stem elongation and leaf area over those grown under polyester. These findings demonstrate the extreme sensitivity of cucumber not only to present levels of UV-B but also to UV-A and suggest that even small changes in ozone depletion may have important biological consequences for certain plant species. (author)

Extended UVB Exposures Alter Tumorigenesis and Treatment Efficacy in a Murine Model of Cutaneous Squamous Cell Carcinoma

Directory of Open Access Journals (Sweden)

Erin M. Burns

2013-01-01

Full Text Available Epidemiological studies support a link between cumulative sun exposure and cutaneous squamous cell carcinoma (SCC development. However, the presumed effects of extended ultraviolet light B (UVB exposure on tumorigenesis in the sexes have not been formally investigated. We examined differences in ultimate tumorigenesis at 25 weeks in mice exposed to UVB for either 10 or 25 weeks. Additionally, we investigated the effect of continued UVB exposure on the efficacy of topical treatment with anti-inflammatory (diclofenac or antioxidant (C E Ferulic or vitamin E compounds on modulating tumorigenesis. Vehicle-treated mice in the 25-week UVB exposure model exhibited an increased tumor burden and a higher percentage of malignant tumors compared to mice in the 10-week exposure model, which correlated with increases in total and mutant p53-positive epidermal cells. Only topical diclofenac decreased tumor number and burden in both sexes regardless of UVB exposure length. These data support the commonly assumed but not previously demonstrated fact that increased cumulative UVB exposure increases the risk of UVB-induced SCC development and can also affect therapeutic efficacies. Our study suggests that cessation of UVB exposure by at-risk patients may decrease tumor development and that topical NSAIDs such as diclofenac may be chemopreventive.

Extended UVB Exposures Alter Tumorigenesis and Treatment Efficacy in a Murine Model of Cutaneous Squamous Cell Carcinoma

International Nuclear Information System (INIS)

Burns, E. M.; Tober, K. L.; Riggenbach, J. A.; Oberyszyn, T. M.; Kusewitt, D. F.; Young, G. S.

2013-01-01

Epidemiological studies support a link between cumulative sun exposure and cutaneous squamous cell carcinoma (SCC) development. However, the presumed effects of extended ultraviolet light B (UVB) exposure on tumorigenesis in the sexes have not been formally investigated. We examined differences in ultimate tumorigenesis at 25 weeks in mice exposed to UVB for either 10 or 25 weeks. Additionally, we investigated the effect of continued UVB exposure on the efficacy of topical treatment with anti-inflammatory (diclofenac) or antioxidant (C E Ferulic or vitamin E) compounds on modulating tumorigenesis. Vehicle-treated mice in the 25-week UVB exposure model exhibited an increased tumor burden and a higher percentage of malignant tumors compared to mice in the 10-week exposure model, which correlated with increases in total and mutant p53-positive epidermal cells. Only topical diclofenac decreased tumor number and burden in both sexes regardless of UVB exposure length. These data support the commonly assumed but not previously demonstrated fact that increased cumulative UVB exposure increases the risk of UVB-induced SCC development and can also affect therapeutic efficacies. Our study suggests that cessation of UVB exposure by at-risk patients may decrease tumor development and that topical NSAIDs such as diclofenac may be chemo preventive.

Developmental responses of amphibians to solar and artificial UVB sources: a comparative study

International Nuclear Information System (INIS)

Hays, J.B.; Hoffman, P.D.; Pandelova, Iovanna; Coyle, Daniel

1996-01-01

Many amphibian species, in widely scattered locations, currently show population declines and/or reductions in range, but other amphibian species show no such declines. There is no known single cause for these declines. Differential sensitivity to UVB radiation among species might be one contributing factor. We have focused on amphibian eggs, potentially the most UVB-sensitive stage, and compared their resistance to UVB components of sunlight with their levels of photolyase, typically the most important enzyme for repair of the major UV photoproducts in DNA, cyclobutane pyrimidine dimers. (Author)

UV-B radiation-induced oxidative stress and p38 signaling pathway involvement in the benthic copepod Tigriopus japonicus.

Science.gov (United States)

Kim, Bo-Mi; Rhee, Jae-Sung; Lee, Kyun-Woo; Kim, Min-Jung; Shin, Kyung-Hoon; Lee, Su-Jae; Lee, Young-Mi; Lee, Jae-Seong

2015-01-01

Ultraviolet B (UV-B) radiation presents an environmental hazard to aquatic organisms. To understand the molecular responses of the intertidal copepod Tigriopus japonicus to UV-B radiation, we measured the acute toxicity response to 96 h of UV-B radiation, and we also assessed the intracellular reactive oxygen species (ROS) levels, glutathione (GSH) content, and antioxidant enzyme (GST, GR, GPx, and SOD) activities after 24 h of exposure to UV-B with LD50 and half LD50 values. Also, expression patterns of p53 and hsp gene families with phosphorylation of p38 MAPK were investigated in UV-B-exposed copepods. We found that the ROS level, GSH content, and antioxidant enzyme activity levels were increased with the transcriptional upregulation of antioxidant-related genes, indicating that UV-B induces oxidative stress by generating ROS and stimulating antioxidant enzymatic activity as a defense mechanism. Additionally, we found that p53 expression was significantly increased after UV-B irradiation due to increases in the phosphorylation of the stress-responsive p38 MAPK, indicating that UV-B may be responsible for inducing DNA damage in T. japonicus. Of the hsp family genes, transcriptional levels of hsp20, hsp20.7, hsp70, and hsp90 were elevated in response to a low dose of UV-B radiation (9 kJ m(-2)), suggesting that these hsp genes may be involved in cellular protection against UV-B radiation. In this paper, we performed a pathway-oriented mechanistic analysis in response to UV-B radiation, and this analysis provides a better understanding of the effects of UV-B in the intertidal benthic copepod T. japonicus. Copyright © 2014 Elsevier Inc. All rights reserved.

Ozone depletion, related UVB changes and increased skin cancer incidence

Science.gov (United States)

Kane, R. P.

1998-03-01

Stratospheric ozone at middle latitudes shows a seasonal variation of about +/-20%, a quasi-biennial oscillation of 1-10% range and a long-term variation in which the level was almost steady up to about 1979 and declined thereafter to the present day by about 10%. These variations are expected to be reflected in solar UVB observed at the ground, but in an opposite direction. Thus UVB should have had a long-term increase of about 10-20%, which should cause an increase in skin cancer incidence of about 20-40%. Skin cancer incidence has increased all over the world, e.g. about 90% in USA during 1974-1990. It is popularly believed that this increase in skin cancer incidence is related to the recent ozone depletion. This seems to be incorrect, for two reasons. Firstly, the observed skin cancer increase is too large (90%) compared with the expected value (40%) from ozone depletion. Secondly, cancer does not develop immediately after exposure to solar UVB. The sunburns may occur within hours; but cancer development and detection may take years, even decades. Hence the observed skin cancer increase since 1974 (no data available for earlier periods) must have occurred due to exposure to solar UVB in the 1950s and 1960s, when there was no ozone depletion. Thus, the skin cancer increase must be attributed to harmful solar UVB levels existing even in the 1960s, accentuated later not by ozone depletion (which started only much later, by 1979) but by other causes, such as a longer human life span, better screening, increasing tendencies of sunbathing at beaches, etc., in affluent societies. On the other hand, the recent ozone depletion and the associated UVB increases will certainly take their toll; only that the effects will not be noticed now but years or decades from now. The concern for the future expressed in the Montreal Protocol for reducing ozone depletion by controlling CFC production is certainly justified, especially because increased UVB is harmful to animal and

Ultra-violet B (UVB)-induced skin cell death occurs through a cyclophilin D intrinsic signaling pathway

International Nuclear Information System (INIS)

Ji, Chao; Yang, Bo; Yang, Zhi; Tu, Ying; Yang, Yan-li; He, Li; Bi, Zhi-Gang

2012-01-01

Highlights: ► UVB radiated skin keratinocytes show cyclophilin D (Cyp-D) upregulation. ► NAC inhibits UVB induced Cyp-D expression, while H 2 O 2 facilitates it. ► Cyp-D-deficient cells are significantly less susceptible to UVB induced cell death. ► Over-expression of Cyp-D causes spontaneous keratinocytes cell death. -- Abstract: UVB-induced skin cell damage involves the opening of mitochondrial permeability transition pore (mPTP), which leads to both apoptotic and necrotic cell death. Cyclophilin D (Cyp-D) translocation to the inner membrane of mitochondrion acts as a key component to open the mPTP. Our Western-Blot results in primary cultured human skin keratinocytes and in HaCaT cell line demonstrated that UVB radiation and hydrogen peroxide (H 2 O 2 ) induced Cyp-D expression, which was inhibited by anti-oxidant N-acetyl cysteine (NAC). We created a stable Cyp-D deficiency skin keratinocytes by expressing Cyp-D-shRNA through lentiviral infection. Cyp-D-deficient cells were significantly less susceptible than their counterparts to UVB- or H 2 O 2 -induced cell death. Further, cyclosporine A (Cs-A), a Cyp-D inhibitor, inhibited UVB- or H 2 O 2 -induced keratinocytes cell death. Reversely, over-expression of Cyp-D in primary keratinocytes caused spontaneous keratinocytes cell death. These results suggest Cyp-D’s critical role in UVB/oxidative stress-induced skin cell death.

Changes in epicuticular flavonoids and photosynthetic pigments as a plant response to UV-B radiation

Energy Technology Data Exchange (ETDEWEB)

Cuadra, P.; Harborne, J. B. [Universidad de Magallances, Punta Arenas (Chile)

1996-07-01

Treatment of Gnaphalium vira-vira plants with UV-B radiation caused changes in plant growth and in plant chemistry. The leaf surface contained two O-methylated flavones, araneol and 7-O-methylaraneol. HPLC analysis showed that 20 days of UV-B radiation increased the synthesis of 7-O-methylaraneol at the expense of araneol. Spectrophotometric analysis of the photosynthetic pigments showed that UV-B radiation also increases the pigment content in treated plants. Another U V alteration is epidermal hair damage, as observed in SEM pictures of treated leaves. This combination of physiological and phytochemical effects may be interpreted as a plant response to UV-B stress.

Changes in epicuticular flavonoids and photosynthetic pigments as a plant response to UV-B radiation

International Nuclear Information System (INIS)

Cuadra, P.; Harborne, J.B.

1996-01-01

Treatment of Gnaphalium vira-vira plants with UV-B radiation caused changes in plant growth and in plant chemistry. The leaf surface contained two O-methylated flavones, araneol and 7-O-methylaraneol. HPLC analysis showed that 20 days of UV-B radiation increased the synthesis of 7-O-methylaraneol at the expense of araneol. Spectrophotometric analysis of the photosynthetic pigments showed that UV-B radiation also increases the pigment content in treated plants. Another U V alteration is epidermal hair damage, as observed in SEM pictures of treated leaves. This combination of physiological and phytochemical effects may be interpreted as a plant response to UV-B stress

The response of bean plants to UV-B radiation under different irradiances of background visible light

International Nuclear Information System (INIS)

Cen, Y.P.; Bornman, J.F.

1990-01-01

Plants of Phaseolus vulgaris L. (cv. Stella) were grown in controlled conditions under three different irradiances of visible light with or without UV-B (280–320nm) radiation. The biologically effective UV-B radiation (UV-BBE) was 6.17 kJ m −2 d −1 , and simulated a c. 5% decrease in stratospheric ozone at 55.7°N, 13.4°E. The photon flux densities of the photosynthetically active radiation (PAR, 400–700 nm) were either 700 μmol m −2−1 (HL), 500, μmol m −2 s −1 (ML) or 230 μmol m −2 s −1 PAR (LL). Under high light (HL) conditions plus UV-B radiation, bean plants appeared most resistant to the enhanced levels of UV-B radiation, and responded only by increasing leaf thickness by c. 18%. A small increase in UV screening pigments was also observed. Both the lower irradiances (ML and LL) increased the sensitivity of the plants to UV-B radiation. Changes in leaf structure were also observed. Photosystem II was inhibited under ML and LL together with UV-B radiation, as determined by Chi fluorescence induction and calculation of the fluorescence half-rise times. Leaf reflectivity measurements showed that the amount of PAR able to penetrate leaves of UV-B treated plants was reduced, and that a possible correlation may exist between the reduced PAR levels, loss of Chi and lowered photosynthetic activity, especially for LL +UV-B grown plants, where surface reflection from leaves was highest. Changes in leaf chlorophyll content were mostly confined to plants grown under LL + UV-B, where a decrease of c. 20% was found. With regard to protective pigments (the carotenoids and UV screening pigments) plants subjected to different visible light conditions responded differently. Among the growth parameters measured, there was a substantial decrease in leaf area, particularly under LL + UV-B (c. 47% relative to controls), where leaf dry weight was also reduced by c. 25%. (author)

Distinct physiological and metabolic reprogramming by highbush blueberry (Vaccinium corymbosum) cultivars revealed during long-term UV-B radiation.

Science.gov (United States)

Luengo Escobar, Ana; Alberdi, Miren; Acevedo, Patricio; Machado, Mariana; Nunes-Nesi, Adriano; Inostroza-Blancheteau, Claudio; Reyes-Díaz, Marjorie

2017-05-01

Despite the Montreal protocol and the eventual recovery of the ozone layer over Antarctica, there are still concerns about increased levels of ultraviolet-B (UV-B) radiation in the Southern Hemisphere. UV-B induces physiological, biochemical and morphological stress responses in plants, which are species-specific and different even for closely related cultivars. In woody plant species, understanding of long-term mechanisms to cope with UV-B-induced stress is limited. Therefore, a greenhouse UV-B daily course simulation was performed for 21 days with two blueberry cultivars (Legacy and Bluegold) under UV-B BE irradiance doses of 0, 0.07 and 0.19 W m -2 . Morphological changes, photosynthetic performance, antioxidants, lipid peroxidation and metabolic features were evaluated. We found that both cultivars behaved differently under UV-B exposure, with Legacy being a UV-B-resistant cultivar. Interestingly, Legacy used a combined strategy: initially, in the first week of exposure its photoprotective compounds increased, coping with the intake of UV-B radiation (avoidance strategy), and then, increasing its antioxidant capacity. These strategies proved to be UV-B radiation dose dependent. The avoidance strategy is triggered early under high UV-B radiation in Legacy. Moreover, the rapid metabolic reprogramming capacity of this cultivar, in contrast to Bluegold, seems to be the most relevant contribution to its UV-B stress-coping strategy. © 2016 Scandinavian Plant Physiology Society.

Solar UV-B radiation modulates chemical defenses against Anticarsia gemmatalis larvae in leaves of field-grown soybean.

Science.gov (United States)

Dillon, Francisco M; Chludil, Hugo D; Zavala, Jorge A

2017-09-01

Although it is well known that solar ultraviolet B (UV-B) radiation enhances plant defenses, there is less knowledge about traits that define insect resistance in field-grown soybean. Here we study the effects of solar UV-B radiation on: a) the induction of phenolic compounds and trypsin proteinase inhibitors (TPI) in soybean undamaged leaves or damaged by Anticarsia gemmatalis neonates during six days, and b) the survival and mass gain of A. gemmatalis larvae that fed on soybean foliage. Two soybean cultivars (cv.), Charata and Williams, were grown under plastic with different transmittance to solar UV-B radiation, which generated two treatments: ambient UV-B (UVB+) and reduced UV-B (UVB-) radiation. Solar UV-B radiation decreased survivorship by 30% and mass gain by 45% of larvae that fed on cv. Charata, but no effect was found in those larvae that fed on cv. Williams. TPI activity and malonyl genistin were induced by A. gemmatalis damage in both cultivars, but solar UV-B radiation and damage only synergistically increased the induction of these compounds in cv. Williams. Although TPI activity and genistein derivatives were induced by herbivory, these results did not explain the differences found in survivorship and mass gain of larvae that fed on cv. Charata. However, we found a positive association between lower larval performance and the presence of two quercetin triglycosides and a kaempferol triglycoside in foliage of cv. Charata, which were identified by HPLC-DAD/MS 2 . We conclude that exclusion of solar UV-B radiation reduce resistance to A. gemmatalis, due to a reduction in flavonol concentration in a cultivar that has low levels of genistein derivatives like cv. Charata. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of UV-B irradiation on isoforms of antioxidant enzymes and their activities in red alga Grateloupia filicina (Rhodophyta)

Science.gov (United States)

Zhao, Jiqiang; Li, Lixia

2014-11-01

Macroalgae in a littoral zone are inevitably exposed to UV-B irradiance. We analyzed the effects of UV-B on isoenzyme patterns and activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ascorbate peroxidase (APX) of red algae Grateloupia filicina (Lamour.) C. Agardh. The activities of SOD, CAT, and APX changed in response to UV-B in a time- and dose-dependent manner. POX activity increased significantly under all three UV-B treatments. The enzymatic assay showed three distinct bands of SODI (Mn-SOD), SODII (Fe-SOD), and SODIII (CuZn-SOD) under a low (Luv) and medium (Muv) dose of UV-B irradiation, while SODI and SODIII activities decreased significantly when exposed to a high dose of UV-B irradiation (Huv). The activity of POX isoenzymes increased significantly after exposure to UV-B, which is consistent with the total activity. In addition, a clear decrease in activity of CATIV was detected in response to all the three doses of UV treatments. Some bands of APX isoenzyme were also clearly influenced by UV-B irradiation. Correspondingly, the daily growth rate declined under all the three exposure doses, and was especially significant under Muv and Huv treatments. These data suggest that, although the protection mechanisms of antioxidant defense system are partly inducible by UV-B to prevent the damage, G. filicina has incomplete tolerance to higher UV-B irradiation stress.

On induced-modifications in optical properties of Makrofol® DE 1-1 SSNTD by UVB and UVA

Science.gov (United States)

Al-Amri, A.; El Ghazaly, M.; Abdel-Aal, M. S.

The induced modifications in the optical properties of Makrofol® DE 1-1 solid state nuclear track detectors upon irradiation by UVB (302 nm) and UVA (365 nm) were characterized and compared. Makrofol® DE 1-1 detectors were irradiated separately for different durations with UVB (302 nm) and UVA (365 nm). The measurements revealed insignificant changes were observed at all in UVA (365 nm)-irradiated Makrofol® DE 1-1, irrespective the irradiation time (dose). All UVB (302 nm)-irradiated Makrofol® DE 1-1 detectors show a substantial red shift in UV-Vis spectra and a continuous increase in absorbance as the exposure time (Dose) to UVB increases. UVC-irradiated Makrofol® DE 1-1 exhibits absorption bands at 315 ± 5 nm in UV-visible spectra. The absorption increases exponential with the increasing the UVB irradiation time gets saturated started from 75 h to 400 h. In the visible light range no significant changes were observed in Makrofol® DE 1-1 detector irrespective the exposure time to UVB of 302 nm. It is found that the direct band gap is higher than indirect band gap and both decrease with the increase in the irradiation time of UVB of 302 nm. The obtained results of the Urbach energy and carbon atoms per cluster indicate that both increase with the increase in the irradiation time to UVB (302 nm). The induced modification in the optical properties of Makrofol® DE 1-1 can be used in UVB dosimetry, meanwhile it is not applicable for UVA of 365 nm.

Protective effect of different antioxidant agents in UVB-irradiated keratinocytes

Directory of Open Access Journals (Sweden)

Sara Salucci

2017-09-01

Full Text Available Skin cells can respond to UVB-induced damage either by tolerating it, or restoring it through antioxidant activation and DNA repair mechanisms or, ultimately, undergoing programmed cell death, when damage is massive. Nutritional factors, in particular, food antioxidants, have attracted much interest because of their potential use in new preventive, protective, and therapeutic strategies for chronic degenerative diseases, including skin inflammation and cancer. Some polyphenols, present in virgin olive oil, well tolerated by organism after oral administration, show a variety of pharmacological and clinical benefits such as anti-oxidant, anti-cancer, anti-inflammatory, and neuro-protective activities. Here, the protective effects of antioxidant compounds against UV-induced apoptosis have been described in HaCat cell line. Human keratinocytes were pre-treated with antioxidants before UVB exposure and their effects have been evaluated by means of ultrastructural analyses. After UVB radiation, a known cell death trigger, typical apoptotic features, absent in control condition and in antioxidant alone-treated cells, appear. An evident numerical decrease of ultrastructural apoptotic patterns and TUNEL positive nuclei can be observed when natural antioxidants were supplied before cell death induction. These data have been confirmed by molecular investigation of caspase activity. In conclusion, this paper highlights antioxidant compound ability to prevent apoptotic cell death in human keratinocytes exposed to UVB, suggesting, for these molecules, a potential role in preventing skin damage. 

Antagonist Effects of Veratric Acid against UVB-Induced Cell Damages

Directory of Open Access Journals (Sweden)

Deokhoon Park

2013-05-01

Full Text Available Ultraviolet (UV radiation induces DNA damage, oxidative stress, and inflammatory processes in human epidermis, resulting in inflammation, photoaging, and photocarcinogenesis. Adequate protection of skin against the harmful effect of UV irradiation is essential. In recent years naturally occurring herbal compounds such as phenolic acids, flavonoids, and high molecular weight polyphenols have gained considerable attention as beneficial protective agents. The simple phenolic veratric acid (VA, 3,4-dimethoxybenzoic acid is one of the major benzoic acid derivatives from vegetables and fruits and it also occurs naturally in medicinal mushrooms which have been reported to have anti-inflammatory and anti-oxidant activities. However, it has rarely been applied in skin care. This study, therefore, aimed to explore the possible roles of veratric acid in protection against UVB-induced damage in HaCaT cells. Results showed that veratric acid can attenuate cyclobutane pyrimidine dimers (CPDs formation, glutathione (GSH depletion and apoptosis induced by UVB. Furthermore, veratric acid had inhibitory effects on the UVB-induced release of the inflammatory mediators such as IL-6 and prostaglandin-E2. We also confirmed the safety and clinical efficacy of veratric acid on human skin. Overall, results demonstrated significant benefits of veratric acid on the protection of keratinocyte against UVB-induced injuries and suggested its potential use in skin photoprotection.

Impact of UV-B radiation on photosynthetic assimilation of 14C-bicarbonate and inorganic 15N-compounds by cyanobacteria

International Nuclear Information System (INIS)

Doehler, G.; Biermann, I.; Zink, J.

1986-01-01

The cyanobacteria Anabaena cylindrica and Synechococcus leopoliensis (=Anacystis nidulans) were grown at different levels of UV-B radiation (439, 717, 1230 and 1405 J m -2 d -1 , weighted according Caldwell, 1971) for 2 days. Dry weight was hardly affected but phycocyanin content of both species decreased linearly to the level of UV-B radiation. Contents of protein, carotenoids and chlorophyll a were reduced only after exposure to high doses (1230 J m -2 d -1 ) of UV-B radiation. Photosynthetic 14 CO 2 fixation of Anabaena cells was reduced linearly with increasing UV-B dose whereas no effect could be observed in Synechococcus. A depression of photosynthetic 15 N-nitrate uptake was found after UV-B stress in both species. UV-B irradiance caused an increase of 15 N-incorporation into glutamine, but no effect was noted for incorporation into alanine or aspartic acid. An increase of 15 N-excess in glutamic acid linear with the UV-B dose was observed in Synechococcus, only. Patterns of 14 C-labelled photosynthetic products were either less affected by UV-B radiation (Anabaena) or an enhancement of 14 C-label in total amino acids was detected (Synechococcus). The amount of total free amino acids increased parallel to the level of UV-B radiation. Only, the high dose of UV-B (1405 J m -2 d -1 , weighted) results in a decrease of the glutamine pool. Our results indicate an inhibition of glutamate synthase by UV-B irradiation in Anabaena, only. Results were discussed with reference to the damage of the photosynthetic apparatus. (orig.)

The sensitivity of sunflower (Helianthus annuus L. plants to UV-B radiation is altered by nitrogen status

Directory of Open Access Journals (Sweden)

Inês Cechin

2018-02-01

Full Text Available ABSTRACT: Interaction effects between nitrogen and UV-B radiation were studied in sunflower (Helianthus annuus L. variety IAC-Iarama plants grown in a greenhouse under natural photoperiod conditions. Plants were irradiated with 0.8W m-2 (control or 8.0W m-2 (+UV-B of UV-B radiation for 7h per day. The plants were grown in pots containing vermiculite and watered with 70% of full strength nitrogen-free Long Ashton solution, containing either low (42.3ppm or high (282ppm nitrogen as ammonium nitrate. High nitrogen increased dry matter of stem, leaves and shoot, photosynthetic pigments and photosynthesis (A without any alteration in stomatal conductance (gs nor transpiration (E while it reduced the intercellular CO2 (Ci concentration, and malondialdehyde (MDA content. High UV-B radiation had negative effects on dry matter production, A, gs and E with the effects more marked under high nitrogen, whereas it increased Ci under high nitrogen. Activity of PG-POD was reduced by high UV-B radiation under low nitrogen but it was not changed under high nitrogen. The UV-B radiation increased the MDA content independently of nitrogen level. Results indicate that the effects of UV-B radiation on sunflower plants are dependent of nitrogen supply with high nitrogen making their physiological processes more sensitive to UV-B radiation.

The mechanisms of protection of antioxidants on Nostoc sphaeroides against UV-B radiation

Science.gov (United States)

Wang, G. H.

UV radiation is one of space harmful factor for earth organisms in space exploration In the present work we studied on the role of antioxidant system in Nostoc sphaeroides K u tz Cyanobacteria and the effects of exogenous antioxidant molecules on its photosynthetic rate under UV-B radiation It was found that UV-B radiation decreased the photosynthetic activity of cyanobacterium but promoted the activity of antioxidant system to protect photosystem II PSII and exogenous antioxidant sodium nitroprusside SNP N-acetylcysteine NAC had an obvious protection on PSII activity under UV-B radiation The activity of SOD Superoxide Dismutase EC 1 15 1 1 CAT Catalase EC 1 11 1 6 POD Peroxidase EC 1 11 1 7 and content of MDA and ASC were improved by 0 5mM and 1mM SNP but 0 1mM SNP decreased the activity of antioxide system Exogenous NAC addition decreased the activity of SOD POD CAT and the content MDA and ASC but exogenous NAC addition increased the content of GSH The results suggested that exogenous SNP and NAC may protect algae by different mechanisms in which SNP maybe play double roles as sources of reactive free radicals or ROS scavengers in formation of algae s protection of PSII under UV-B radiation while NAC does function as antioxidant reagent or precursor of glutathione which could protect PSII directly from UV-B radiation Keyword antioxidant system exogenous or endogenous antioxidant Nostoc sphaeroides photosynthesis UV-B radiation

Effects of enhanced UV-B radiation on Mentha spicata essential oils

International Nuclear Information System (INIS)

Karousou, R.; Grammatikopoulos, G.; Lanaras, T.; Manetas, Y.; Kokkini, S.

1998-01-01

In vitro propagated plantlets representing two distinct chemotypes of Mentha spicata, viz. plants producing essential oils rich in piperitone oxide and piperitenone oxide (chemotype I) and rich in carvone and dihydrocarvone (chemotype II), were grown in the field under ambient or ambient plus supplemental UV-B radiation, biologically equivalent to a 15% ozone depletion over Patras (38.3°N, 29.1°E), Greece. Enhanced UV-B radiation stimulated essential oil production in chemotype II substantially, while a similar, non-significant trend was observed in chemotype I. No effect was found on the qualitative composition of the essential oils, whereas the quantitative composition was slightly modified in chemotype I. This is the first investigation reporting an improved essential oil content under UV-B supplementation in aromatic plants under field conditions

Decontamination of groundwater. Shortcomings of groundwater prospecting - opportunities of and limits to conventional and more recent decontamination methods; Sanierung von Grundwasserschaeden. Defizite der Grundwassererkundung - Moeglichkeiten und Grenzen konventioneller und neuerer Sanierungsverfahren

Energy Technology Data Exchange (ETDEWEB)

Toussaint, B. [Hessische Landesanstalt fuer Umwelt, Wiesbaden (Germany); Rehner, G. [GfS Gesellschaft fuer Boden- und Grundwassersanierung mbh, Kirchheim/Teck (Germany); Held, T. [Trischler und Partner GmbH, Darmstadt (Germany)

1998-12-31

Contaminated ground water aquifers require prospecting; where the levels of dangerous substances exceed threshold values action must be taken to minimize hazards. But both in prospecting as well as safeguarding and decontamination, grave errors are made. In the first part, an overview from the hydrogeological viewpoint is given on the state-of-the-art planning and execution of ground-water-related prospecting and evaluation, the results of which provide the basis for all following measures. Part two discusses the scope and limits of decontamination techniques with the emphasis on modern methods such as underwater evaporator wells and special in-situ bio-technical processes. Case histories, too, permit readers to recognize which planning steps and operations are particularly often fraught with error having economic and ecological impacts. The knowledge provided by the book is an essential prerequisite for more successful execution of decontamination measures. (orig.) [Deutsch] Ein kontaminierter Grundwasserleiter muss erkundet werden, im Falle einer Ueberschreitung von stoffbezogenen Schwellenwerten sind gefahrenminimierende Massnahmen durchzufuehren. Sowohl bei Erkundungs- als auch bei Sicherungs- oder Sanierungsmassnahmen werden z.T. gravierende Fehler gemacht. Das Buch vermittelt im ersten Teil aus der Sicht von Hydrogeologen einen Ueberblick ueber den Stand von Wissenschaft und Technik bei der Planung und Durchfuehrung von auf das Grundwasser bezogenen Erkundungs- und Bewertungsstrategien, deren Ergebnisse Grundlagen fuer alle nachfolgenden Massnahmen sind. Im zweiten Teil werden Moeglichkeiten und Grenzen von Sanierungstechniken diskutiert, wobei auf moderne Verfahren wie z.B. Unterwasser-Verdampfer-Brunnen und biotechnische in situ-Verfahren besonderer Wert gelegt wird. Auch anhand von Fallbeispielen kann der Leser erkennen, bei welchen Planungs- und Arbeitsschritten besonders haeufig sich oekonomisch und oekologisch auswirkende Fehler gemacht werden. Die von

Ultra-violet B (UVB)-induced skin cell death occurs through a cyclophilin D intrinsic signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Ji, Chao [Department of Dermatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210024, Jiangsu (China); Yang, Bo [Department of Dermatology, Huashan Hospital, Fudan University, Shanghai 200040 (China); Yang, Zhi; Tu, Ying [Department of Dermatology, The First Affiliated Hospital of Kunming Medical University, Yunnan Provincial Institute of Dermatology, Kunming 650032, Yunnan (China); Yang, Yan-li [Department of Otorhinolaryngology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210024, Jiangsu (China); He, Li, E-mail: heli2662@yahoo.com.cn [Department of Otorhinolaryngology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210024, Jiangsu (China); Bi, Zhi-Gang, E-mail: eltonbibenqhospital@yahoo.com.cn [Department of Dermatology, BenQ Medical Center, Nanjing Medical University, Nanjing 210019, Jiangsu (China)

2012-09-07

Highlights: Black-Right-Pointing-Pointer UVB radiated skin keratinocytes show cyclophilin D (Cyp-D) upregulation. Black-Right-Pointing-Pointer NAC inhibits UVB induced Cyp-D expression, while H{sub 2}O{sub 2} facilitates it. Black-Right-Pointing-Pointer Cyp-D-deficient cells are significantly less susceptible to UVB induced cell death. Black-Right-Pointing-Pointer Over-expression of Cyp-D causes spontaneous keratinocytes cell death. -- Abstract: UVB-induced skin cell damage involves the opening of mitochondrial permeability transition pore (mPTP), which leads to both apoptotic and necrotic cell death. Cyclophilin D (Cyp-D) translocation to the inner membrane of mitochondrion acts as a key component to open the mPTP. Our Western-Blot results in primary cultured human skin keratinocytes and in HaCaT cell line demonstrated that UVB radiation and hydrogen peroxide (H{sub 2}O{sub 2}) induced Cyp-D expression, which was inhibited by anti-oxidant N-acetyl cysteine (NAC). We created a stable Cyp-D deficiency skin keratinocytes by expressing Cyp-D-shRNA through lentiviral infection. Cyp-D-deficient cells were significantly less susceptible than their counterparts to UVB- or H{sub 2}O{sub 2}-induced cell death. Further, cyclosporine A (Cs-A), a Cyp-D inhibitor, inhibited UVB- or H{sub 2}O{sub 2}-induced keratinocytes cell death. Reversely, over-expression of Cyp-D in primary keratinocytes caused spontaneous keratinocytes cell death. These results suggest Cyp-D's critical role in UVB/oxidative stress-induced skin cell death.

A protective effect of anthocyanins and xanthophylls on UVB-induced damage in retinal pigment epithelial cells.

Science.gov (United States)

Silván, Jose Manuel; Reguero, Marina; de Pascual-Teresa, Sonia

2016-02-01

Increased exposure to solar ultraviolet B (UVB) radiation causes oxidative damage that may promote age related macular degeneration (AMD) and other ocular pathologies. This study is aimed to demonstrate the protective effects of some anthocyanins and xanthophylls against the UVB-induced oxidative damage to retinal pigment epithelial (RPE) cells. ARPE-19 cells were treated with 5 μM cyanidin-3-O-glucoside, delphinidin-3-O-glucoside, lutein, zeaxanthin or a mixture of cyanidin-3-O-glucoside:zeaxanthin prior to UVB exposure (500 J m(-2)). Cell viability and mitogen-activated protein kinase (MAPK) phosphorylation were determined by MTT assay and western blot analysis, respectively. Oxidative damage was evaluated by measuring the intracellular reactive oxygen species (ROS). The data showed that UVB irradiation reduces the cell viability to 46% with increasing of intracellular ROS levels and phosphorylation of MAPKs. However, pre-treatment (60 min) with 5 μM cyanidin-3-O-glucoside, lutein or zeaxanthin significantly reduced cellular ROS levels and phosphorylation of MAPKs (JNK1/2 and p38) mediated by UVB irradiation and subsequently increased cell viability. Thus, results show that UVB irradiation is able to induce apoptosis in ARPE-19 cells through oxidative stress; however anthocyanins and xanthophylls pre-treatment can attenuate this damage. This suggests that cyanidin-3-O-glucoside, lutein and zeaxanthin are effective in preventing UVB-induced damage in RPE cells and may be suitable as chemoprotective factors for the prevention of ocular damage. The use of natural dietary antioxidants might reduce ocular oxidative damage caused by UVB radiation.

Exclusion of UV-B radiation from normal solar spectrum on the growth of mung bean and maize

International Nuclear Information System (INIS)

Pal, M.; Sharma, A.; Abrol, Y.P.; Sengupta, U.K.

1997-01-01

The increase in UV-B radiation due to depletion of the ozone layer has potentially harmful effects on plant growth and performance. The bulk of these studies conducted in growth chambers, greenhouses or in the field use different types of exposure systems which may be responsible for differences in the sensitivity of a crop to UV-B radiation. A field study using selective filters to remove the UV-B portion of the solar spectrum was conducted with mung bean (a dicotyledonous C 3 plant) and maize (a monocotyledonous C 4 plant) to determine the sensitivity of these crop plants to ambient UV-B levels without disturbing the microenvironment. Mung bean was found to be sensitive to ambient UV-B levels in terms of leaf area development, plant height attained and net photosynthesis, while maize was found to be unaffected by ambient UV-B levels (22.8 |GmW cm −2 nm −1 ) found in Delhi, India (28°38′N, 77°13′E). The level of ambient UV-B radiation thus appears to be inhibitory for optimal growth of plants, especially dicotyledonous mung bean. (author)

Effects of UVB radiation on net community production in the upper global ocean

KAUST Repository

Garcia-Corral, Lara S.; Holding, Johnna M.; Carrillo-de-Albornoz, Paloma; Steckbauer, Alexandra; Pé rez-Lorenzo, Marí a; Navarro, Nuria; Serret, Pablo; Duarte, Carlos M.; Agusti, Susana

2016-01-01

Our results suggest that earlier estimates of NCP for surface communities, which were hitherto derived using materials blocking UVB radiation were biased, with the direction and magnitude of this bias depending on the metabolic status of the communities and the underwater penetration of UVB radiation.

Recall of UVB-induced erythema in breast cancer patient receiving multiple drug chemotherapy

DEFF Research Database (Denmark)

Andersen, Klaus Ejner; Lindskov, R

1984-01-01

One day after sunbathing, a breast cancer patient received intravenous methotrexate, cyclophosphamide and 5-fluorouracil and had a recall of her UV erythema over the following week. Phototesting with UVA and UVB prior to and after a subsequent chemotherapy treatment showed a UVB-induced recall...

Effects of enhanced UVB on growth and yield of alfalfa and soybean under field conditions

International Nuclear Information System (INIS)

Al-Oudat, M.; Baydon, S.A.; Mohamad, A.

1998-01-01

The effects of 20% increase of UVB on growth and yield of alfalfa (Medicago Sativa L.) and two cultivars of soybean (Glycine Max (L.) Mer) under field conditions have been investigated. The increase of UVB dose ranged between 1.746 and 7.112 J/cm 2 during experiment. The results showed that soybean yield decrease by 16% and 31% in A. 3803 and A. 2522 cultivars respectively, under UVB exposure. The dry weight and leaf area were sensitive in the A. 3803 cultivar, while they were tolerant in the A. 2522 cultivar. Alfalfa response to UVB varied during the different stages of growth, whereas the yield was 12% less in the exposed plants. (author)

Dichotomy in response to indomethacin in uv-C and uv-B induced ultraviolet light inflammation

International Nuclear Information System (INIS)

Eaglstein, W.H.; Marsico, A.R.

1975-01-01

In subjects irradiated with both UV-C and UV-B ultraviolet light (UVL), 10 μg of intradermal indomethacin decreased the redness in all 13 of the UV-B irradiated areas but in only 2 of 13 of the UV-C irradiated areas. Higher doses of intradermal indomethacin (50 μg and 100 μg) decreased the redness produced by UV-C irradiation in 6 subjects. It is suggested that the failure of 10 μg of indomethacin to decrease the redness of the UV-C induced inflammation, while decreasing the redness in the UV-B induced inflammation, is consistent with the possibility that prostaglandins participate in UV-B but not UV-C induced inflammation

Joint additive effects of temperature and UVB radiation on zoeae of the crab Taliepus dentatus

KAUST Repository

Carreja, B

2016-04-06

Warming and enhanced ultraviolet B (UVB) radiation are 2 global stressors acting across the ocean. We tested their effects on the survival and performance (consumption rates and activity) on the zoea I stage of the Chilean kelp crab Taliepus dentatus. Our goal was to resolve whether these stressors, when acting concurrently, had additive or interactive effects, either synergistic or antagonistic. A multifactorial experiment of 4 temperatures and 3 UVB irradiance levels was run. The larvae showed a significant increase in mortality with increasing temperature. Exposure to UVB reduced the thermal tolerance of the larvae by a significant increase of their mortality rate. Oxygen consumption increased as temperature increased. When exposed to UVB radiation, larval oxygen consumption increased significantly for all the temperatures tested. Two statistical models of joint effects confirmed that the combined effect of both stressors was additive, with no interaction, either synergistic or antagonistic. One of them, the independent action (IA) model, also revealed that concurrent effects on mortality remained additive when doubling the UVB dose. Additivity of the stressors improved the predictability of their effects on larval mortality. Exposure to UVB radiation increased mortality rates by 1.5 times at any temperature tested, independently of the dose. © The authors 2016.

Joint additive effects of temperature and UVB radiation on zoeae of the crab Taliepus dentatus

KAUST Repository

Carreja, B; Ferná ndez, M; Agusti, Susana

2016-01-01

Warming and enhanced ultraviolet B (UVB) radiation are 2 global stressors acting across the ocean. We tested their effects on the survival and performance (consumption rates and activity) on the zoea I stage of the Chilean kelp crab Taliepus dentatus. Our goal was to resolve whether these stressors, when acting concurrently, had additive or interactive effects, either synergistic or antagonistic. A multifactorial experiment of 4 temperatures and 3 UVB irradiance levels was run. The larvae showed a significant increase in mortality with increasing temperature. Exposure to UVB reduced the thermal tolerance of the larvae by a significant increase of their mortality rate. Oxygen consumption increased as temperature increased. When exposed to UVB radiation, larval oxygen consumption increased significantly for all the temperatures tested. Two statistical models of joint effects confirmed that the combined effect of both stressors was additive, with no interaction, either synergistic or antagonistic. One of them, the independent action (IA) model, also revealed that concurrent effects on mortality remained additive when doubling the UVB dose. Additivity of the stressors improved the predictability of their effects on larval mortality. Exposure to UVB radiation increased mortality rates by 1.5 times at any temperature tested, independently of the dose. © The authors 2016.

Long-term effects of elevated UV-B radiation on photosynthesis and ultrastructure of Eriophorum russeolum and Warnstorfia exannulata

International Nuclear Information System (INIS)

Haapala, Jaana K.; Moersky, Sami K.; Saarnio, Sanna; Suokanerva, Hanne; Kyroe, Esko; Silvola, Jouko; Holopainen, Toini

2010-01-01

The depletion of stratospheric ozone above the Arctic regions may increase the amount of UV-B radiation to which the northern ecosystems are exposed. In this paper, we examine the hypothesis that supplemental UV-B radiation may affect the growth rate and photosynthesis of boreal peatland plants and could thereby affect the carbon uptake of these ecosystems. In this study, we report the effects of 3-year exposure to elevated UV-B radiation (46% above ambient) on the photosynthetic performance and ultrastructure of a boreal sedge Eriophorum russeolum and a moss Warnstorfia exannulata. The experiment was conducted on a natural fen ecosystem at Sodankylae in northern Finland. The effects of UV-B radiation on the light response of E. russeolum CO 2 assimilation and the maximal photochemical efficiency of photosystem II in a dark-adapted state (F v /F m ) were measured in the field. In addition, the effect of supplemental UV-B radiation on organelles of photosynthetic cells was studied by electron microscopy. The UV-B treatment had no effect on the CO 2 assimilation rate of either species, nor did it affect the structure of the cell organelles. On chlorophyll fluorescence, the UV-B exposure had only a temporary effect during the third exposure year. Our results suggested that in a natural ecosystem, even long-term exposure to reasonably elevated UV-B radiation levels does not affect the photosynthesis of peatland plants. - Research highlights: →Eriophorum russeolum and Warnstorfia exannulata are resistant to UV-B radiation →UV-B exposure does not affect the growth or photosynthesis of E. russeolum →Long-term UV-B exposure has no effect on the ultrastructure of E. russeolum

Beneficial effects of solar UV-B radiation on soybean yield mediated by reduced insect herbivory under field conditions.

Science.gov (United States)

Mazza, Carlos A; Giménez, Patricia I; Kantolic, Adriana G; Ballaré, Carlos L

2013-03-01

Ultraviolet-B radiation (UV-B: 280-315 nm) has damaging effects on cellular components and macromolecules. In plants, natural levels of UV-B can reduce leaf area expansion and growth, which can lead to reduced productivity and yield. UV-B can also have important effects on herbivorous insects. Owing to the successful implementation of the Montreal Protocol, current models predict that clear-sky levels of UV-B radiation will decline during this century in response to ozone recovery. However, because of climate change and changes in land use practices, future trends in UV doses are difficult to predict. In the experiments reported here, we used an exclusion approach to study the effects of solar UV-B radiation on soybean crops, which are extensively grown in many areas of the world that may be affected by future variations in UV-B radiation. In a first experiment, performed under normal management practices (which included chemical pest control), we found that natural levels of UV-B radiation reduced soybean yield. In a second experiment, where no pesticides were applied, we found that solar UV-B significantly reduced insect herbivory and, surprisingly, caused a concomitant increase in crop yield. Our data support the idea that UV-B effects on agroecosystems are the result of complex interactions involving multiple trophic levels. A better understanding of the mechanisms that mediate the anti-herbivore effect of UV-B radiation may be used to design crop varieties with improved adaptation to the cropping systems that are likely to prevail in the coming decades in response to agricultural intensification. Copyright © Physiologia Plantarum 2012.

Trichome density and its UV-B protective potential are affected by shading and leaf position on the canopy

International Nuclear Information System (INIS)

Liakoura, V.; Stefanou, M.; Manetas, Y.; Cholevas, C.; Karabourniotis, G.

1997-01-01

In Olea europaea trichome density and UV-B absorbing compounds of leaf hairs and the lamina proper of leaves located in south-facing, north-facing and the internal of the canopy were positively correlated to the UV-B midday instant irradiance measured in September at these three different positions of the canopy. The correlation between these three parameters and the receiving photosynthetically active radiation (PAR), however, was weaker. In Quercus ilex, trichome density and its UV-B absorbing capacity were considerably higher in the exposed, south-facing leaves, compared to the deeply shaded ones; the UV-B absorbing capacity of the de-haired lamina, however, was the same. In the broad-leaved, alpine rosette of Verbascum speciosum, one could distinguish two areas on the leaves, one exposed and one shaded by the superimposed lamina. Although trichome density and the UV-B absorbing compounds of the de-haired leaf were the same in the two areas, the UV-B absorbing capacity of hairs was considerably increased in the exposed region. In V. speciosum, exposure induced also qualitative changes in the UV-B absorbance profile, apparently due to the formation of new flavonoid compounds absorbing maximally at 345–350 nm. In all other cases, the differences were mainly quantitative. The results support the postulate of a function of leaf hairs as a UV-B radiation screen and suggest that trichome density and/or its UV-B absorbing capacity may depend on irradiance during leaf development

The influence of enhanced UV-B radiation on Batrachium trichophyllum and Potamogeton alpinus -- aquatic macrophytes with amphibious character.

Science.gov (United States)

Germ, Mateja; Mazej, Zdenka; Gaberscik, Alenka; Häder, Donat P

2002-02-01

The responses of two amphibious species, Batrachium trichophyllum and Potamogeton alpinus to different UV-B environments were studied. Plant material from natural environments, as well as from outdoor treatments was examined. In long-term outdoor experiments plants were grown under three different levels of UV-B radiation: reduced and ambient UV-B levels, and a UV-B level simulating 17% ozone depletion. The following parameters were monitored: contents of total methanol soluble UV-absorbing compounds and chlorophyll a, terminal electron transport system (ETS) activity and optimal and effective quantum yield of photosystem II. No effect of the different UV-B levels on the measured parameters was observed. The amount of UV-B absorbing compounds seems to be saturated, since no differences were observed between treatments and no increase was found in peak season, when natural UV-B levels were the highest. Physiological measurements revealed no harmful effects; neither on potential and actual photochemical efficiency, nor on terminal ETS activity. The contents of UV-B absorbing compounds were examined also in plant material sampled in low and high altitude environments during the growth season. Both species exhibited no seasonal dynamics of production of UV-absorbing compounds. The contents were variable and showed no significant differences between high and low altitude populations.

UV-B Radiation Impacts Shoot Tissue Pigment Composition in Allium fistulosum L. Cultigens

Directory of Open Access Journals (Sweden)

Kristin R. Abney

2013-01-01

Full Text Available Plants from the Allium genus are valued worldwide for culinary flavor and medicinal attributes. In this study, 16 cultigens of bunching onion (Allium fistulosum L. were grown in a glasshouse under filtered UV radiation (control or supplemental UV-B radiation [7.0 μmol·m−2·s−2 (2.68 W·m−2] to determine impacts on growth, physiological parameters, and nutritional quality. Supplemental UV-B radiation influenced shoot tissue carotenoid concentrations in some, but not all, of the bunching onions. Xanthophyll carotenoid pigments lutein and β-carotene and chlorophylls a and b in shoot tissues differed between UV-B radiation treatments and among cultigens. Cultigen “Pesoenyj” responded to supplemental UV-B radiation with increases in the ratio of zeaxanthin + antheraxanthin to zeaxanthin + antheraxanthin + violaxanthin, which may indicate a flux in the xanthophyll carotenoids towards deepoxydation, commonly found under high irradiance stress. Increases in carotenoid concentrations would be expected to increase crop nutritional values.

Probing behaviors of Sitobion avenae (Hemiptera: Aphididae on enhanced UV-B irradiated plants

Directory of Open Access Journals (Sweden)

Hu Zu-Qing

2013-01-01

Full Text Available UV-B induced changes in plants can influence sap-feeding insects through mechanisms that have not been studied. Herein the grain aphid, Sitobion avenae (Fabricius (Hemiptera: Aphididae, was monitored on barley plants under the treatments of control [0 kJ/ (m2.d], ambient UV-B [60 kJ/ (m2.d], and enhanced UV-B [120 kJ/ (m2.d] irradiation. Electrical penetration graph (EPG techniques were used to record aphid probing behaviors. Enhanced UV-B irradiated plants negatively affected probing behaviors of S. avenae compared with control plants. In particular, phloem factors that could diminish sieve element acceptance appeared to be involved, as reflected by smaller number of phloem phase, shorter phloem ingestion, and fewer aphids reaching the sustained phloem ingestion phase (E2>10min. On the other hand, factors from leaf surface, epidermis, and mesophyll cannot be excluded, as reflected by higher number of non-probing, longer non-probing and pathway phase, and later the time to first probe.

Anthropogenic changes in the surface all-sky UV-B radiation through 1850-2005 simulated by an Earth system model

Science.gov (United States)

Watanabe, S.; Takemura, T.; Sudo, K.; Yokohata, T.; Kawase, H.

2012-06-01

The historical anthropogenic change in the surface all-sky UV-B (solar ultraviolet: 280-315 nm) radiation through 1850-2005 is evaluated using an Earth system model. Responses of UV-B dose to anthropogenic changes in ozone and aerosols are separately evaluated using a series of historical simulations including/excluding these changes. Increases in these air pollutants cause reductions in UV-B transmittance, which occur gradually/rapidly before/after 1950 in and downwind of industrial and deforestation regions. Furthermore, changes in ozone transport in the lower stratosphere, which is induced by increasing greenhouse gas concentrations, increase ozone concentration in the extratropical upper troposphere and lower stratosphere. These transient changes work to decrease the amount of UV-B reaching the Earth's surface, counteracting the well-known effect increasing UV-B due to stratospheric ozone depletion, which developed rapidly after ca. 1980. As a consequence, the surface UV-B radiation change between 1850 and 2000 is negative in the tropics and NH extratropics and positive in the SH extratropics. Comparing the contributions of ozone and aerosol changes to the UV-B change, the transient change in ozone absorption of UV-B mainly determines the total change in the surface UV-B radiation at most locations. On the other hand, the aerosol direct and indirect effects on UV-B play an equally important role to that of ozone in the NH mid-latitudes and tropics. A typical example is East Asia (25° N-60° N and 120° E-150° E), where the effect of aerosols (ca. 70%) dominates the total UV-B change.

Contrasting Responses of Marine and Freshwater Photosynthetic Organisms to UVB Radiation: A Meta-Analysis

KAUST Repository

Jin, Peng; Duarte, Carlos M.; Agusti, Susana

2017-01-01

artificial lamps. We found that marine photosynthetic organisms tend to be more sensitive than freshwater photosynthetic organisms to UVB radiation; responses to either decreased or increased UVB radiation vary among taxa; the mortality rate is the most

Protective effect of 4-coumaric acid from UVB ray damage in the rabbit eye.

Science.gov (United States)

Lodovici, Maura; Caldini, Silvia; Morbidelli, Lucia; Akpan, Victor; Ziche, Marina; Dolara, Piero

2009-01-08

UV-induced oxidation damage seems to play a major role in a number of specific pathological conditions of intraocular tissues, such as cataract formation and retinal degeneration. Therefore, antioxidant and/or scavenger compounds might protect the eyes from UV-induced cellular damage. We previously reported that 4-coumaric acid (4-CA) is able to protect rabbit corneal-derived cells (SIRC) from UVB-induced oxidation damage. In this study we evaluated the protective effect of 4-CA against UVB-induced cell damage in rabbit cornea in vivo. Twelve male New Zealand albino rabbits were used; four rabbits were used as a control and received vehicle in one eye and 4-CA acid in the contralateral eye; eight rabbits were exposed to UVB rays (79.2mJ/cm(2)) and three days before to UV exposure each animal received 1 drop/day of vehicle in one eye and 1 drop/day of vehicle containing 4-CA (164ng) in the contralateral eye. Corneal and sclera tissues were removed and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) levels were measured. Superoxide dismutase (SOD) and xanthine oxidase (XO) activities were determined in aqueous humour. UVB-induced vessel hyper-reactivity was strongly reduced at 4 and 24h after UVB exposure after local treatment with 4-CA, 8-oxodGuo levels, a marker of oxidative DNA damage, were significantly increased (Peyes. Our results indicate that the administration of 4-CA protects eye tissues, thus reducing the harmful effect of UVB radiation at low concentration, probably through its free radical scavenging and antioxidant properties. Therefore, 4-CA may be useful in protecting the eye from free radical damage following UVB exposure from sunlight, UV lamps and welding torches.

Penetration of UV-B radiation in foliage: evidence that the epidermis behaves as a non-uniform filter

International Nuclear Information System (INIS)

Day, T.A.; Martin, G.; Vogelmann, T.C.

1993-01-01

In some plants, particularly herbaceous species, a considerable proportion of incident ultraviolet-B radiation (UV-B, 280-320 nm) penetrates into the leaf mesophyll where it is potentially damaging to nucleic acids and the photosynthetic machinery. We used optical techniques to look at the spatial variation in UV-B penetration through the epidermis of foliage of two herbaceous species (Chenopodium album and Smilacina stellata) and a conifer (Picea pungens). Measurements of UV-B penetration in intact foliage with a fibre-optic microprobe revealed that 300 nm radiation reached 161±36μm (mean±SD) into leaves of C. album, 154±40μm in S. stellata and 17±2μm in P. pungens, with epidermal transmittance being 39±14%, 55±19% and 0%, respectively. A thin polymer film was developed which fluoresced blue when irradiated by UV-B. Fresh epidermal leaf peels were placed over the film and irradiated with UV-B, and microscopic examination of the film from below allowed us to determine the spatial pattern of UV-B penetration through the epidermis. In herbaceous species, film fluorescence below cell walls, but not epidermal and guard cell protoplasts indicated that UV-B transmittance was much greater through anticlinal cell wall regions than protoplasts. Ultraviolet-B transmittance through large areas of epidermal cells could be induced by plasmolysis. Epidermal transmittance was also relatively high through stomal pores (and what appear to be nuclei in Smilacina), but relatively low through stomatal guard cells. Results from the fluorescing film technique were substantiated by direct measurements of UV-B transmittance through epidermal peels with a fibre-optic microprobe run paradermally along the bottom or inner side of irradiated peels. In Smilacina, we estimate that UV-B epidermal transmittance was up to 90% through anticlinal cell wall regions, but <10% through protoplast areas. In contrast to herbaceous species, we did not detect any UV-B transmittance through the

UV-B induction of NADP-malic enzyme in etiolated and green maize seedlings

International Nuclear Information System (INIS)

Drincovich, M.F.; Casati, P.; Andreo, C.S.; Donahue, R.; Edwards, G.E.

1998-01-01

The effect of treatment of etiolated maize seedlings with UV-B and UV-A radiation, and different levels of photosynthetically active radiation (PAR, 400–700 nm), on the activity and quantity of NADP-malic enzyme (NADPME) and on RNA levels was determined. Under low levels of PAR (14 µmol m –2 s –1 ), exposure to UV-B radiation (9 µmol m –2 s –1 ) but not UV-A radiation (11 µmol m –2 s –1 ) for 6–24 h caused a marked increase in the activity of the enzyme similar to that observed under high PAR (300 µmol m –2 s –1 ) in the absence of UV-B. Western blot analysis indicated there was a specific increase of the photosynthetically active isoform of the enzyme. This increase was also measured at the RNA level by dot blot analysis, indicating that the induction is displayed at the level of NADP-ME transcription. UV-B treatment of green leaves after a 12 h dark period also caused an increase in the activity and level of NADP-ME. The UV-B induction of NADP-ME synthesis may reflect a mechanism for induction of photosynthetic processes in C4 photosynthesis. Alternatively, the relatively low intensity of UV-B radiation present under full sunlight might provide a signal that facilitates repair of UV-B-induced damage through the increased activity of different enzymes such as NADP-ME. It is speculated that the reducing power and pyruvate generated by activity of NADP-ME may be used for respiration in cellular repair processes and as substrates for the fatty acid synthesis required for membrane repair. (author)

Effects of UVB irradiation on keratinocyte growth factor (KGF) and receptor (KGFR) expression in cultured human keratinocytes

Energy Technology Data Exchange (ETDEWEB)

Zhou, Y.; Lee, H.S.T.; Kooshesh, F.; Fujisawa, H.; Sauder, D.N.; Kondo, S. [Univ. of Toronto, Sunnybrook Health Science Centre, Div. of Dermatology, Toronto (Canada)

1996-06-01

Keratinocyte growth factor (KGF) and its receptor (KGFR) are thought to play important roles in normal keratinocyte growth and differentiation. Since UVB radiation is known to influence keratinocyte growth, we sought to determine whether UVB would alter the expression of KGF and KGFR. Using a reverse-transcription coupled polymerase chain reaction (RT-PCR), the present study examined the expression of KGF and KGFR mRNA in cultured normal human keratinocytes exposed to UVB irradiation. Total cellular RNA was extracted from cultured keratinocytes at various time points after irradiation, reverse transcribed and used for PCR amplification using primers specific for KGF and KGFR. Constitutive expression of KGFR mRNA, but not KGF mRNA, was detected in normal cultured human keratinocytes. After UVB irradiation at 300 J/m{sup 2}, the KGF mRNA remained undetectable while the KGFR mRNA level was significantly decreased. The down-regulation of KGFR mRNA expression was also confirmed by Northern blot analysis. Immunohistochemical studies demonstrated a decreased positive signal of KGFR in human keratinocytes after UVB irradiation. Our results suggest a possible role for the KGF-KGFR signalling pathway in the skin after exposure to UVB, and that UVB-induced growth inhibition of keratinocytes in hyperproliferative skin disorders may be related to downregulation of KGFR. (au) 39 refs.

Histopathological responses of newly hatched larvae of whitefish (Coregonus lavaretus s.l.) to UV-B induced toxicity of retene

International Nuclear Information System (INIS)

Haekkinen, Jani; Vehniaeinen, Eeva; Oikari, Aimo

2003-01-01

Positively phototactic fish larvae may be exposed to increased ultraviolet-B (UV-B) radiation alone or, potentially and in addition, to polycyclic aromatic hydrocarbons (PAHs) such as retene (7-isopropyl-1-methylphenanthrene) at the egg or larval stages. Suspended and sedimental particulate material near pulp and paper mills may act as sources of retene in chemically contaminated lake areas. In laboratory conditions whitefish larvae were pre-exposed to retene (10, 32 and 100 μg/l), with relevant controls, and irradiated in semi-static tests for 3 h once a day (2 consecutive days) with two UV-B doses (CIE-weighted 2.8 or 5.4 kJ per m 2 per day) or with visible light only. These UV-B doses correspond with slightly subambient and 80% increases relative to the natural maximum daily doses of the solar UV-B in Finland in early May. The UV-B radiation alone increased mortality only slightly (2.7 and 4.0%, respectively). Similarly, no mortality was observed due to retene alone. On the contrary, simultaneous UV-B and retene exposure caused very high mortality to whitefish and all larvae died in the highest retene concentration. The photoinduced acute LC 50 for retene was 13.3 μg/l. Retene treated fish exhibited signs of behavioral irritation and hypoxia during and after the exposure to UV light. Severe skin damages were detected in larvae exposed simultaneously to retene and UV-B. The structural signs of sunburn could also be seen in UV-B and solvent controls (DMSO) with UV-B. Even at the lowest retene concentration, the number of mucous cells increased significantly in simultaneous chemical and UV-B treatment. We consider the tissue reaction as protective response against UV induced retene toxicity. Further, regarding liver parenchyma, fish exposed to retene with UV-B had lesions, revealing hepatotoxicity. We suggest that synergism of the UV-B radiation and the photoactivating pollutants such as retene is a potential risk factor to be taken into consideration in lake

Apoptosis - Triggering Effects: UVB-irradiation and Saccharomyces cerevisiae.

Science.gov (United States)

Behzadi, Payam; Behzadi, Elham

2012-12-01

The pathogenic disturbance of Saccharomyces cerevisiae is known as a rare but invasive nosocomial fungal infection. This survey is focused on the evaluation of apoptosis-triggering effects of UVB-irradiation in Saccharomyces cerevisiae. The well-growth colonies of Saccharomyces cerevisiae on Sabouraud Dextrose Agar (SDA) were irradiated within an interval of 10 minutes by UVB-light (302 nm). Subsequently, the harvested DNA molecules of control and UV-exposed yeast colonies were run through the 1% agarose gel electrophoresis comprising the luminescent dye of ethidium bromide. No unusual patterns including DNA laddering bands or smears were detected. The applied procedure for UV exposure was not effective for inducing apoptosis in Saccharomyces cerevisiae. So, it needs another UV-radiation protocol for inducing apoptosis phenomenon in Saccharomyces cerevisiae.

The gender differences in the inhibitory action of UVB-induced melanocyte activation by the administration of tranexamic acid.

Science.gov (United States)

Hiramoto, Keiichi; Yamate, Yurika; Sugiyama, Daijiro; Takahashi, Yumi; Mafune, Eiichi

2016-05-01

Tranexamic acid has an inhibitory action on ultraviolet (UV) B-induced melanocyte activation. This study examined the sex differences in the inhibitory action of tranexamic acid on UVB-induced melanocyte activation. We irradiated the eye and ear of male and female mice with UVB at a dose of 1.0 kJ/m(2) using a 20SE sunlamp. We orally administered tranexamic acid (750 mg/kg/day) at 30 min before UVB exposure. Tranexamic acid inhibited the UVB-induced epidermal melanocyte activation, and the effect was more remarkable under UVB eye irradiation than under UVB ear irradiation. Furthermore, the melanocyte activity suppression effect was stronger in female mice than in male mice. Following the administration of tranexamic acid, the female displayed increased blood levels of β-endorphin and μ-opioid receptor and estradiol receptor β expression in comparison with the male. Furthermore, the effect of melanocyte activity suppression in the female mice was decreased by the administration of tamoxifen (antagonist of estrogen receptor) or naltrexone (antagonist of μ-opioid receptor). These results suggest that the suppression by tranexamic acid of the UVB-induced melanocyte activation (UVB sensitivity) is stronger in female mice than in male mice and that female hormones and β-endorphin play an important role in this sex difference. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Protective effect of mango (Mangifera indica L.) against UVB-induced skin aging in hairless mice.

Science.gov (United States)

Song, Jae Hyoung; Bae, Eun Young; Choi, Goya; Hyun, Jin Won; Lee, Mi Young; Lee, Hye Won; Chae, Sungwook

2013-04-01

Mangifera indica L. (Anacardiaceae) is a medicinal plant whose extracts have been described as an antioxidant with anti-inflammatory and immunomodulatory activities. Skin aging is a consequence of chronic sun exposure to the sun and therefore ultraviolet (UV) radiation. Naturally occurring antioxidants are known to reduce skin aging. Therefore, the aim of the present study was to evaluate the protective role of mango extract against UVB-induced skin aging in hairless mice. HR-1 hairless male mice (6 weeks old) were divided into three groups: control (n = 5), UVB-treated vehicle (n = 5), and UVB-treated mango extract (n = 5) groups. UVB-irradiated mice from the mango extract group were orally administered 0.1 ml of water containing 100 mg of mango extract/kg body weight per day. The inhibitory activity of mango extract on wrinkle formation was determined by the analysis of the skin replica, epidermal thickness based on histological examination, and damage to collagen fiber. The mean length of wrinkles in UVB-treated vehicle group significantly improved after the oral administration of mango extract, which significantly inhibited the increase in epidermal thickness and epidermal hypertrophy (P mango extract by Masson's trichrome staining. These results indicate that mango extract showed anti-photoaging activity in UVB-irradiated hairless mice. © 2013 John Wiley & Sons A/S.

Risk assessment of UVB effects on resistance to infectious diseases

International Nuclear Information System (INIS)

Garssen, J.; Goettsch, W.; Slob, W.; Loveren, H. van; de Gruijl, F.

1996-01-01

The aim of this study was to develop a quantitative risk assessment of lowered resistance to infections in humans due to (solar) ultraviolet B (UVB) exposure. We followed the steps for risk assessment as defined by the U.S. National Academy of Sciences: (1) hazard identification, (2) dose-response assessment, (3) exposure assessment, and (4) risk characterization. For step 1, the suppressory effects of UVB radiation on the immune system has been reviewed, supplemented with new data, and analyzed. Experiments on UV-induced immunosuppression cannot be performed with humans for ethical reasons, but herpes simplex virus infection appears to be the human paradigm. Thus, UVB radiation appears to be a potential hazard to immunologic functions. Step 2 is crucial, but dose-response relationships for infections have never been measured in humans. We used our earlier dose-response rat data for suppression of lymphocyte stimulation and computed that the UVB dose resulting in a 50% reduction of lymphocyte stimulation by Listeria monocytogenes is 6.800 J/m 2 . Using mixed skin lymphocyte response assays we found that humans are 3.8 times less sensitive than rats (interspecies variation [IEV]). To account for the 2.5 percentile of most susceptible individuals in a population, an additional factor (intraspecies variation [IAV]) was introduced (0.5 for humans). Using these data, we computed that 13.100 J/m 2 of UVB radiation emitted by FS40 lamps would suppress 50% of the proliferative response of lymphocytes to L. monocytogenes in most sensitive skin type 2 humans. In step 3, we assumed the action spectrum for the responses analyzed by us as identical to an action spectrum for suppression of contact hypersensitivity that is available in the literature. In step 4, we calculated that approximately 100 min of solar exposure at around noon in Italy or Spain would suppress the resistance to infections by L. monocytogenes in the most sensitive humans. (author)

Risk assessment of UVB effects on resistance to infectious diseases

Energy Technology Data Exchange (ETDEWEB)

Garssen, J.; Goettsch, W.; Slob, W.; Loveren, H. van [National Institute of Public Health and Environment, Bilthoven (Netherlands); de Gruijl, F. [Rijksuniversiteit Utrecht (Netherlands)

1996-08-01

The aim of this study was to develop a quantitative risk assessment of lowered resistance to infections in humans due to (solar) ultraviolet B (UVB) exposure. We followed the steps for risk assessment as defined by the U.S. National Academy of Sciences: (1) hazard identification, (2) dose-response assessment, (3) exposure assessment, and (4) risk characterization. For step 1, the suppressory effects of UVB radiation on the immune system has been reviewed, supplemented with new data, and analyzed. Experiments on UV-induced immunosuppression cannot be performed with humans for ethical reasons, but herpes simplex virus infection appears to be the human paradigm. Thus, UVB radiation appears to be a potential hazard to immunologic functions. Step 2 is crucial, but dose-response relationships for infections have never been measured in humans. We used our earlier dose-response rat data for suppression of lymphocyte stimulation and computed that the UVB dose resulting in a 50% reduction of lymphocyte stimulation by Listeria monocytogenes is 6.800 J/m{sup 2}. Using mixed skin lymphocyte response assays we found that humans are 3.8 times less sensitive than rats (interspecies variation [IEV]). To account for the 2.5 percentile of most susceptible individuals in a population, an additional factor (intraspecies variation [IAV]) was introduced (0.5 for humans). Using these data, we computed that 13.100 J/m{sup 2} of UVB radiation emitted by FS40 lamps would suppress 50% of the proliferative response of lymphocytes to L. monocytogenes in most sensitive skin type 2 humans. In step 3, we assumed the action spectrum for the responses analyzed by us as identical to an action spectrum for suppression of contact hypersensitivity that is available in the literature. In step 4, we calculated that approximately 100 min of solar exposure at around noon in Italy or Spain would suppress the resistance to infections by L. monocytogenes in the most sensitive humans. (author).

Effects of solar UVB radiation on growth, flowering and yield of central and southern European maize cultivars (Zea mays L.)

International Nuclear Information System (INIS)

Mark, U.; Saile-Mark, M.; Tevini, M.

1996-01-01

Different cultivars of maize (Zea mays L.) originating from Central and South Europe were grown from June to September 1994 for 16 weeks in two greenhouses covered with different UVB-absorbing (280-320 nm) plastic foils. Using the ambient UVB radiation level of a southern location (Portugal, 38.7 o N) in one of the greenhouses as an enhanced radiation compared to the reduced radiation in the second greenhouse, an increase of about 12% of UVB was simulated. Six of the eight cultivars examined showed significant reductions in height of up to 18.9% at all developmental stages under increased UVB. In contrast to this, the fresh and dry weight as well as the leaf area was reduced under UVB only at early developmental stages, but with ongoing development the UVB stressed plants caught up. The total content of absorbing compounds of the maize cultivars was completely unaffected by UVB. A flowering delay up to a maximum of 5 days was observed under higher UVB in several cultivars. Probably due to this delay in the cob development the yield decreased to 27.7% under higher UVB at the first harvest after 12 and 14 weeks, whereas at the second harvest after 14 and 16 weeks yield reduction levelled off. (Author)

Combined exposure to ambient UVB radiation and nitrite negatively affects survival of amphibian early life stages

International Nuclear Information System (INIS)

Macias, Guadalupe; Marco, Adolfo; Blaustein, Andrew R.

2007-01-01

Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian green frog Rana perezi. We studied R. perezi from both mountain and coastal populations to examine if populations of the same species varied in their response to stressors in different habitats. Both species were sensitive to the two stressors acting alone, but the interaction between the two stressors caused a multiplicative impact on tadpole survival. For B. bufo, the combination of UVB and nitrite was up to seven times more lethal than mortality for each stressor alone. In a coastal wetland, the combination of UVB and nitrite was four times more toxic for R. perezi than the sum of the effect on mortality for each stressor alone. One mg/L of nitrite killed half the population of R. perezi at Gredos Mountains at day 10 in the absence of UVB. In the presence of UVB, 50% of the tadpoles from the same experiment died at day 7. Similar toxic response were found for R. perezi in two highly contrasted environments suggesting this synergistic interaction can be a widespread phenomenon. The interaction of excess chemical fertilizers and manure with ambient UVB radiation could be contributing to the global decline of some amphibian species. We suggest that potential exposure to UVB radiation be accounted for when assessing water quality criteria regarding nitrite pollution

Combined exposure to ambient UVB radiation and nitrite negatively affects survival of amphibian early life stages

Energy Technology Data Exchange (ETDEWEB)

Macias, Guadalupe [Donana Biological Station, CSIC, Spanish Council for Scientific Research. P.O. Box 1056, Sevilla 41013 (Spain); Marco, Adolfo [Donana Biological Station, CSIC, Spanish Council for Scientific Research. P.O. Box 1056, Sevilla 41013 (Spain)], E-mail: amarco@ebd.csic.es; Blaustein, Andrew R. [Department of Zoology, Oregon State University, Corvallis, Oregon, 97331 (United States)

2007-10-15

Many aquatic species are sensitive to ambient levels of ultraviolet-B radiation (UVB) and chemical fertilizers. However, recent studies indicate that the interaction among multiple stressors acting simultaneously could be contributing to the population declines of some animal species. Therefore, we tested the potential synergistic effects between ambient levels of UVB and a contaminant, sodium nitrite in the larvae of two amphibian species, the common European toad Bufo bufo and the Iberian green frog Rana perezi. We studied R. perezi from both mountain and coastal populations to examine if populations of the same species varied in their response to stressors in different habitats. Both species were sensitive to the two stressors acting alone, but the interaction between the two stressors caused a multiplicative impact on tadpole survival. For B. bufo, the combination of UVB and nitrite was up to seven times more lethal than mortality for each stressor alone. In a coastal wetland, the combination of UVB and nitrite was four times more toxic for R. perezi than the sum of the effect on mortality for each stressor alone. One mg/L of nitrite killed half the population of R. perezi at Gredos Mountains at day 10 in the absence of UVB. In the presence of UVB, 50% of the tadpoles from the same experiment died at day 7. Similar toxic response were found for R. perezi in two highly contrasted environments suggesting this synergistic interaction can be a widespread phenomenon. The interaction of excess chemical fertilizers and manure with ambient UVB radiation could be contributing to the global decline of some amphibian species. We suggest that potential exposure to UVB radiation be accounted for when assessing water quality criteria regarding nitrite pollution.

Phototherapy UVB narrow band treatment of psoriasis, mycosis fungoides and vitiligo

International Nuclear Information System (INIS)

Reyes, M.V.; Kutnizky, R.; Bosch, M.P.; Ruiz Lascano, A.

2013-01-01

Introduction: Numerous studies have shown the beneficial effect of ultraviolet radiation for the treatment of lymphoproliferative or inflammatory skin diseases. Objective: To determine the response to UVB narrow band (UVB-nb) in psoriasis, mycosis fungoides stage IA, IB and vitiligo, in the Dermatology Department of Hospital Privado from May 2009 to January 2011. To correlate total energy dose used and the total number of sessions with the response achieved in each disease. To describe adverse reactions; determine demographic characteristics of the population and comorbidities in psoriasis and vitiligo. Material and Methods: We performed a prospective, descriptive, analytical, observational study. We included all patients assessed for initiation of UVB-nb. Regarding the patients who did not start or interrupted the treatment a survey was conducted to assess the causes. We calculated the cumulative dose and number of sessions at the end of treatment. (authors) [es

Effect of enhanced UV-B radiation of adaxial leaf surface micromorphology and epicuticular wax biosynthesis of sugar maple

International Nuclear Information System (INIS)

Gordon, D.C.; Percy, K.E.; Riding, R.T.

1998-01-01

Sugar maple (Acer saccharum [Marsh.]) seedlings were exposed to UV-B BE ranging from 0.61 kJ m -2 d -1 to 12.48 kJ m -2 d -1 . Increasing UV-B intensity was associated with changes in micromorphological characteristics of the adaxial leaf surface. In vivo incorporation of [1- 14 C] acetate into sugar maple adaxial leaf surface epicuticular wax indicated (p<0.05) a UV-B sensitivity threshold at or near 6.2 kJ m -2 d -1 . Exposure to dosages greater than 6.2 kJ m -2 d -1 resulted in a significant (p<0.05) decrease in wax biosynthesis. The proportion of [1- 14 C] acetate incorporated into each of the different epicuticular wax classes changed with increasing UV-B. Incorporation of [1- 14 C] acetate into alkyl esters decreased while incorporation into alkanes increased with increasing UV-B dose. The effects of enhanced UV-B dose recorded in this experiment may have implications for cuticle function. (author)

Psoriasis treatment: faster and long-standing results after bathing in geothermal seawater. A randomized trial of three UVB phototherapy regimens.

Science.gov (United States)

Eysteinsdóttir, Jenna Huld; Ólafsson, Jón Hjaltalín; Agnarsson, Bjarni A; Lúðvíksson, Björn Rúnar; Sigurgeirsson, Bárður

2014-02-01

The combination of seawater baths and narrowband ultraviolet B (NB-UVB) is a known treatment for psoriasis. This study evaluates two treatment regimens that combine bathing in geothermal seawater and NB-UVB therapy in comparison with NB-UVB monotherapy. Sixty-eight psoriasis patients were randomly assigned to outpatient bathing in geothermal seawater combined with NB-UVB therapy three times a week, intensive daily treatment involving bathing in geothermal seawater combined with NB-UVB therapy, or NB-UVB therapy alone three times a week; treatment period was 6 weeks. Disease severity [Psoriasis Area Severity Index (PASI) and Lattice System Physician's Global Assessment scores], quality of life (Dermatology Life Quality Index) and histological changes were evaluated before, during and after treatment. The primary end point was the proportion of patients who achieved PASI 75 at 6 weeks. At 6 weeks, the percentage of patients who achieved PASI 75 and PASI 90 was significantly greater for both regimens, bathing in geothermal seawater three times a week (68.1% and 18.2%, respectively) and intensive treatment with geothermal seawater (73.1% and 42.3%, respectively) than for NB-UVB monotherapy (16.7% and 0%, respectively) (P seawater combined with NB-UVB therapy in psoriasis induces faster clinical and histological improvement, produces longer remission time and permits lower NB-UVB doses than UVB therapy alone. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of UV-B radiation on a hereditary suture cataract in mice

International Nuclear Information System (INIS)

Forker, Carina; Wegener, Alfred

1997-01-01

UV-B (290-320 nm, λ max = 305 nm) radiation and the Cat2 ns (suture cataract) mutation in mice affect both the anterior lens epithelium and the formation of the suture. A low dose of UV-B radiation (2.2 Jcm -2 ) induces similar anterior subcapsular and cortical lens opacities in wild type as in heterozygous mutant mice. The UV-B treatment of the mutant lenses, however, leads to an increase in the number of epithelial cell layers in the anterior central part as compared to the wild type indicating a more severe form of the cataract formation in mutants. In addition, mutants demonstrate a predisposition for a rupture of the posterior lens capsule, because from 2.9 Jcm -2 and higher, this phenomenon could always be observed in the UV-B treated mutants, but never in the treated wild type mice. The protein biochemical analyses were performed by gel electrophoresis and isoelectric focusing of extracts of total lenses or from defined areas of the lens (lens slice technique). These covered the patterns of those proteins already synthesized before irradiation, which in irradiated lenses in no case evidenced a difference to the untreated control, neither in the wild type nor in the mutants. In contrast, by analysing specifically those proteins, which are synthesized after irradiation, in both treated groups a protein with a molecular mass of about 31 kDa becomes discernable in both treated groups. In addition, the cataractous lenses demonstrate a significantly enhanced overall synthesis of water-soluble proteins after irradiation, which might promote the rupture of the posterior capsule at the posterior pole. The present study offers for the first time the possibility to discriminate between endogeneous (genetic) effects and exogeneous (environmental) effects in cataractogenesis and to study their interactive effects. The first set of experiments demonstrated a clear intensification of the hereditary cataract by the UV-B treatment. The study supports the hypothesis that

A morphological and cytological study of Petunia hybrida exposed to UV-B radiation

International Nuclear Information System (INIS)

Staxén, I.; Bornmann, J.F.

1994-01-01

The aim of this study was to investigate whether the cytoskeleton, and in particular the microtubular system, is affected by enhanced levels of ultraviolet-B (280–320 nm, 9 kJ m −2 day −1 biologically effective UV-B radiation) radiation in epidermal cells of Petunia x hybrida Vilm, isolated from leaves of plants grown under UV-B radiation and visible light. In addition, morphological changes during development were monitored. In a previous study microtubules were depolymerized and delays in the different stages of the cell cycle were found when protoplasts of Petunia were irradiated with UV-B radiation (Staxén et al. 1993. Protoplasma 173: 70–76). Thus it was of interest to ascertain whether the cytoskeleton would be similarly affected in an intact system. Assuming an effect of UV-B radiation on the microtubular system, we wished to determine whether this could be correlated to concomitant changes in leaf morphology. Plants of Petunia hybrida were grown in greenhouse conditions in the presence or absence of UV-B radiation. During the course of the experiment, samples were taken from young, expanding leaves and from older, fully expanded leaves and prepared for localization and analysis of microtubules from the adaxial epidermal cells. Morphology rather than the cytoskeleton was affected by UV radiation, despite the fact that the epidermal cytoskeleton would most likely be affected, since it is located in the cells which form the first intercepting layer for incident radiation. Morphological changes under UV-B radiation, as compared to those under control conditions, were reflected in earlier flowering and an increase in leaf number. Cell division was thus stimulated as was also evidenced from the increased leaf area. Our results indicate that the number of stomata differentiated on a leaf area basis was not altered although the number of stomata per epidermal cell was reduced. (author)

Effect of enhanced UV-B radiation on yield and quality of rice

International Nuclear Information System (INIS)

Yin Hong; Guo Wei; Mao Xiaoyan

2009-01-01

The effects of enhanced UV-B radiation on yield and quality of two rice cuhivars(ShenNong 6014 and ShenNong 265) are studied in potted method. There were three treatments including natural light (TCK), enhanced 5% UV-B radiation (T) and enhanced 10% (T). The results showed that enhanced UV-B radiation decreases yield components, the percentage of brown rice (0.66%-7.06%), head rice rate (5.65%-18.88%), the rate of white rice (22.17%-40.16%), grain area (2.61%-6.25%), fatty acid contents (1.23%-54.19%) and eating quality (1.07%-16.78%) but increasea protein content (4.65%-10.71%) and amylose content of rice (0.56%-4.81%). The effects of T2 was stronger than T1

AKT delays the early-activated apoptotic pathway in UVB-irradiated keratinocytes via BAD translocation.

Science.gov (United States)

Claerhout, Sofie; Decraene, David; Van Laethem, An; Van Kelst, Sofie; Agostinis, Patrizia; Garmyn, Marjan

2007-02-01

Upon irradiation with a high dose of UVB, keratinocytes undergo apoptosis as a protective mechanism. In previous work, we demonstrated the existence of an early-activated UVB-induced apoptotic pathway in growth factor-depleted human keratinocytes, which can be substantially delayed by the exclusive supplementation of IGF-1. We now show that in human keratinocytes, IGF-1 inhibits the onset of UVB-triggered apoptosis through a transcriptional independent, AKT-mediated mechanism, involving BAD serine 136 phosphorylation. Our results show that the early UVB-induced apoptosis in growth factor-depleted human keratinocytes is exclusively triggered through the mitochondrial pathway. It is accompanied by BAX translocation, cytochrome c release, and procaspase-9 cleavage, but not by procaspase-8 or BID cleavage. In human keratinocytes, IGF-1 supplementation inhibits these events in a transcription-independent manner. Both IGF-1 supplementation and the transduction of a membrane-targeted form of AKT result in a shift of the BH3-only protein BAD from the mitochondria to the cytoplasm, paralleled by an increase of AKT-specific Ser136 phospho-BAD bound to 14-3-3zeta protein. These data indicate that AKT-induced BAD phosphorylation and its subsequent cytoplasmic sequestration by 14-3-3zeta is a major mechanism responsible for the postponement of UVB-induced apoptosis in human keratinocytes.

Influence of light, UV-B radiation, and herbicides on wax biosynthesis of cucumber seedlings

International Nuclear Information System (INIS)

Tevini, M.; Steinmüller, D.

1987-01-01

The behavior of cuticular alkane-1-ols and alkanes were studied in different developmental stages of cucumber seedlings grown in the dark or under white light, with or without UV-B radiation or in presence of wax biosynthesis inhibitors, trichloroacetic acid and metolachlor. Accumulation of alkane-1-ols increased light independently with seedling age. Synthesis of alkanes was strictly light and dose dependent. Addition of UV-B radiation did not alter the amounts of alkanes or alcohols, however, the distribution of homologues was shifted towards shorter chain homologues. Treatments with Cl 3 AcOH resulted in strong inhibition of alkane accumulation, whereas the amount of alkane-1-ols was changed neither at low nor at moderate concentrations of Cl 3 AcOH but their homologue distribution shifted towards longer chain lengths. This shifting was depressed in the presence of UV-B. At high concentrations of Cl 3 Ac0H similar homologue distributions as produced by UV-B (shift to shorter homologues) were observed. Metolachlor treatment resulted in an inhibition of alkane-1-ol production connected with rising amounts of alkanes, predominantly of short chain species. A simple model of wax biosynthesis is proposed which describes the interactions with white light, UV-B radiation and herbicides. (author)

Effect of UV-B Radiation and Desiccation Stress on Photoprotective Compounds Accumulation in Marine Leptolyngbya sp.

Science.gov (United States)

Joshi, Devika; Mohandass, C; Dhale, Mohan

2018-01-01

Increased awareness regarding the harmful effects of ultraviolet (UV)-B radiation has led to the search for new sources of natural UV-B protecting compounds. Mycosporine-like amino acids are one of such promising compounds found in several organisms. Cyanobacteria are ideal organisms for isolation of these compounds due to their compatibility and adaptability to thrive under harsh environmental conditions. In the following investigation, we report the production of shinorine in Leptolyngbya sp. isolated from the intertidal region. Based on the spectral characteristics and liquid chromatography-mass spectrometry analysis, the UV-absorbing compound was identified as shinorine. To the best of our knowledge, this is the first report on the occurrence of shinorine in Leptolyngbya sp. We also investigated the effect of artificial UV-B radiation and periodic desiccation on chlorophyll-a, total carotenoids, and mycosporine-like amino acids (MAAs) production. The UV-B radiation had a negative effect on growth and chlorophyll concentration, whereas it showed an inductive effect on the production of total carotenoids and MAAs. Desiccation along with UV-B radiation led to an increase in the concentration of photoprotective compounds. These results indicate that carotenoids and MAAs thus facilitate cyanobacteria to avoid and protect themselves from the deleterious effects of UV-B and desiccation.

Effects of increasing UV-B radiation and atmospheric CO2 on photosynthesis and growth: implications for terrestrial ecosystems

International Nuclear Information System (INIS)

Sullivan, J.H.

1997-01-01

Increases in UV-B radiation reaching the earth as a result of stratospheric ozone depletion will most likely accompany increases in atmospheric CO 2 concentrations. Many studies have examined the effects of each factor independently, but few have evaluated the combined effects of both UV-B radiation and elevated CO 2 . In general the results of such studies have shown independent effects on growth or seed yield. Although interspecific variation is large, high levels of UV-B radiation tends to reduce plant growth in sensitive species, while CO 2 enrichment tends to promote growth in most C 3 species. However, most previous studies have not looked at temporal effects or at the relationship between photosynthetic acclimation to CO 2 and possible photosynthetic limitations imposed by UV-B radiation. Elevated CO 2 may provide some protection against UV-B for some species. In contrast, UV-B radiation may limit the ability to exploit elevated CO 2 in other species. Interactions between the effects of CO 2 enrichment and UV-B radiation exposure have also been shown for biomass allocation. Effects on both biomass allocation and photosynthetic acclimation may be important to ecosystem structure in terms of seedling establishment, competition and reproductive output. Few studies have evaluated ecosystem processes such as decomposition or nutrient cycling. Interactive effects may be subtle and species specific but should not be ignored in the assessment of the potential impacts of increases in CO 2 and UV-B radiation on plants. (author)

In vivo UVB irradiation induces clustering of Fas (CD95) on human epidermal cells

DEFF Research Database (Denmark)

Bang, Bo; Gniadecki, Robert; Larsen, Jørgen K

2003-01-01

a single dose of UVB irradiation. Normal healthy individuals were irradiated with three minimal erythema doses (MED) of UVB on forearm or buttock skin. Suction blisters from unirradiated and irradiated skin were raised, and Fas, FasL, and apoptosis of epidermal cells quantified by flow cytometry...

Combined impact of solar UV-B radiation and selenium treatment on respiratory potential in pumpkins (Cucurbita pepo L.)

International Nuclear Information System (INIS)

Germ, M.

2005-01-01

The effects of ambient and filtered solar UV-B radiation and of selenium treatment on respiratory potential measured by electron transport system (ETS) activity in pumpkins, Cucurbita pepo L. were studied. Measurements were conducted three times in the growth period. Solar UV-B radiation decreased ETS activity in plants, regardless selenium treatment. The results suggested that the solar UV-B radiation impaired flow of electrons in the respiratory chain. Selenium decreased ETS activity in plants exposed to solar UV-B radiation in the end of the vegetation period

Histopathological responses of newly hatched larvae of whitefish (Coregonus lavaretus s.l.) to UV-B induced toxicity of retene

Energy Technology Data Exchange (ETDEWEB)

Haekkinen, Jani; Vehniaeinen, Eeva; Oikari, Aimo

2003-04-10

Positively phototactic fish larvae may be exposed to increased ultraviolet-B (UV-B) radiation alone or, potentially and in addition, to polycyclic aromatic hydrocarbons (PAHs) such as retene (7-isopropyl-1-methylphenanthrene) at the egg or larval stages. Suspended and sedimental particulate material near pulp and paper mills may act as sources of retene in chemically contaminated lake areas. In laboratory conditions whitefish larvae were pre-exposed to retene (10, 32 and 100 {mu}g/l), with relevant controls, and irradiated in semi-static tests for 3 h once a day (2 consecutive days) with two UV-B doses (CIE-weighted 2.8 or 5.4 kJ per m{sup 2} per day) or with visible light only. These UV-B doses correspond with slightly subambient and 80% increases relative to the natural maximum daily doses of the solar UV-B in Finland in early May. The UV-B radiation alone increased mortality only slightly (2.7 and 4.0%, respectively). Similarly, no mortality was observed due to retene alone. On the contrary, simultaneous UV-B and retene exposure caused very high mortality to whitefish and all larvae died in the highest retene concentration. The photoinduced acute LC{sub 50} for retene was 13.3 {mu}g/l. Retene treated fish exhibited signs of behavioral irritation and hypoxia during and after the exposure to UV light. Severe skin damages were detected in larvae exposed simultaneously to retene and UV-B. The structural signs of sunburn could also be seen in UV-B and solvent controls (DMSO) with UV-B. Even at the lowest retene concentration, the number of mucous cells increased significantly in simultaneous chemical and UV-B treatment. We consider the tissue reaction as protective response against UV induced retene toxicity. Further, regarding liver parenchyma, fish exposed to retene with UV-B had lesions, revealing hepatotoxicity. We suggest that synergism of the UV-B radiation and the photoactivating pollutants such as retene is a potential risk factor to be taken into

Responses of phylloplane yeasts to UV-B (290-320 nm) radiation: interspecific differences in sensitivity

International Nuclear Information System (INIS)

Gunasekera, T.S.; Paul, N.D.; Ayres, P.G.

1997-01-01

The sensitivity to UV-B (290–320 nm) radiation of common phylloplane yeasts from two contrasting UV-B environments was compared in the laboratory using mixtures of white light (PAR: 400–700 nm) and UV-B radiation from artificial lamp sources. Sporidiobolus salmonicolor, Rhodotorula mucilaginosa and Cryptococcus sp., the dominant yeasts on leaves of tea (Camellia sinensis), were isolated in Sri Lanka (SL), while Sporidiobolus sp. and Bullera alba, dominant on faba bean (Vicia faba), were isolated in the U.K. Dose responses were determined separately for each yeast. UV-B reduced colony forming units (due to cell mortality or inactivation) and colony size (due to reduced multiplication) of all yeasts. The LD 50 values and doses causing 50% reduction of cells per colony were higher for SL isolates than U.K. isolates. Results indicated that each yeast is somewhat vulnerable to UV-B doses representative of its natural habitat. The relative insensitivity of SL isolates was shown when SL and U.K. isolates were irradiated simultaneously with the same dose of UV-B. Of the two U.K. yeasts, B. alba was significantly more sensitive than Sporidiobolus sp. to UV-B. Except for R. mucilaginosa from SL, all yeasts demonstrated some photorepair in the presence of white light. White light provided relatively little protection for the U.K. isolate of Sporidiobolus sp. although it allowed increased colony size. The spectral responses of Sporidiobolus sp. (U.K.) and of B. alba (U.K.) were broadly similar. Wavelengths longer than 320 nm had no measurable effect on colony forming units. However, colony survival was significantly reduced at 310 nm and all shorter wavebands. No colonies were counted at 290 nm or below. (author)

Effects of lanthanum(III) on nitrogen metabolism of soybean seedlings under elevated UV-B radiation.

Science.gov (United States)

Cao, Rui; Huang, Xiao-hua; Zhou, Qing; Cheng, Xiao-ying

2007-01-01

The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm). The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Compared with the control, UV-B radiation with the intensity of low level 0.15 W/m2 and high level 0.45 W/m2 significantly affected the whole nitrogen metabolism in soybean seedlings (p nitrogen-metabolism-related enzymes, such as: nitrate reductase (NR) to the nitrate reduction, glutamine systhetase (GS) and glutamine synthase (GOGAT) to the ammonia assimilation, while it increased the content of free amino acids and decreased that of soluble protein as well. The damage effect of high level of UV-B radiation on nitrogen metabolism was greater than that of low level. And UV-B radiation promoted the activity of the anti-adversity enzyme glutamate dehydrogenase (GDH), which reduced the toxicity of excess ammonia in plant. After pretreatment with the optimum concentration of La (20 mg/L), La could increase the activity of NR, GS, GOGAT, and GDH, and ammonia assimilation, but decrease nitrate and ammonia accumulation. In conclusion, La could relieve the damage effect of UV-B radiation on plant by regulating nitrogen metabolism process, and its alleviating effect under low level was better than that under the high one.

Effects of UV-B radiation and water stress on gas exchange of soybeans under two different nitrogen levels

International Nuclear Information System (INIS)

Rosa, L.M.; Forseth, I.N.

1993-01-01

Due to anthropogenic destruction of stratospheric ozone, UV-B radiation is projected to increase in the near future. Other potential global climate changes in temperature and precipitation patterns raise the need for research into plant responses to multiple environmental stresses. The objective of this study was to document UV-B and water stress effects on gas exchange of soybean (Glycine max Merr.) under two nitrogen levels. Two soybean cultivars differing in sensitivity to UV-B were tested at fluence rates of 19.1 or 8.5 kJ m -2 day -1 (enhance and natural levels of UV-B, respectively). Measurements of photosaturated CO 2 uptake at ambient CO 2 (A). stomatal conductance. photosaturated O 2 evolution at saturating CO 2 (A max ), long term water use efficiency (using δ 13 C), and nitrogen fixation (using 15 N) were performed. No significant treatment effects on A could be detected. However A max was significantly increased, and stomatal conductance reduced (p<0.01) by increased UV-B at all levels of water and nitrogen for both cultivars, suggesting a stronger stomal limitation of photosynthesis under UV-B. Water and nitrogen use efficiency also decreased under increased UV-B in both cultivars (p<0.01)

Protective effect of infrared-A radiation against damage induced by UVB radiation in the melan-a cell line.

Science.gov (United States)

Portantiolo Lettnin, Aline; Teixeira Santos Figueiredo Salgado, Mariana; Gonsalez Cruz, Camila; Manoel Rodrigues da Silva-Júnior, Flávio; Cunha Gonzalez, Vinícius; de Souza Votto, Ana Paula; Santos Trindade, Gilma; de Moraes Vaz Batista Filgueira, Daza

2016-10-01

The present work evaluated the infrared-A (IR-A) protective effect using a light-emitting diode (LED) lamp against the cytotoxic effects of ultraviolet B radiation (UVB). Effects on cell viability (Trypan blue assay), DNA damage (comet assay), lipid peroxidation (FOX method), reactive oxygen species production and antioxidant capacity were analyzed in melan-a, a non-tumoral murine melanocytic cell line. To define the doses used in the interaction experiments between IR-A+UVB, dose/response curves were made after exposure to IR-A or UVB. The IR-A dose chosen was 0.8J/cm(2) because this dose caused no significant inhibition of proliferation effects and viability decreased. For UVB exposure, a dose of 0.015J/cm(2), which showed a decrease in viable cell number by approximately 50% in relation to control until 72h, was selected. For IR-A+UVB, cell proliferation recovery was showed, decreasing DNA damage and lipid peroxide content when compared to UVB alone. Besides, the results obtained for ROS and antioxidant capacity showed that the protection observed was probably not related to decreased oxidative stress. In conclusion, non-thermal IR-A was capable of protecting the melan-a cells from UVB induced damage. Copyright © 2016 Elsevier B.V. All rights reserved.

TiO2 nanoparticles as an effective UV-B radiation skin-protective compound in sunscreens

International Nuclear Information System (INIS)

Popov, A P; Priezzhev, A V; Lademann, J; Myllylae, R

2005-01-01

Protecting human skin against harmful UV-B radiation coming from the sun is currently a problem. Due to the decreased thickness of the ozone layer, a more dangerous amount of UV-B light reaches the surface of our planet. This causes increased frequency of skin diseases. Titanium dioxide (TiO 2 ) fine particles are embedded with sunscreens into the skin to effectively attenuate UV-B radiation. This study evaluates the most appropriate size of such particles assuming they are spheres. The distribution of TiO 2 particles within the skin, achieved with topically applied sunscreens, is determined experimentally by the tape-stripping technique. Computer code implementing the Monte Carlo method is used to simulate photon migration within the plain 20 μm thick horny layer matrix partially filled with nano-sized TiO 2 particles. Dependences of harmful UV-B radiation of 307-311 nm absorbed by, backscattered from and transmitted through the horny layer on the concentration of TiO 2 particles are obtained and analysed. As a result, particles of 62 nm are found to be the most effective in protecting skin against UV-B light

UVB emitting LiSrBO3 phosphor for phototherapy lamp

Science.gov (United States)

Kunghatkar, R. G.; Hemne, P. S.; Dhoble, S. J.

2018-05-01

LiSrBO3 doped Gadolinium have been synthesized by sol gel technique. The formation of host was confirmed by XRD techniques. The incorporation of Gd3+ was confirmed by photoluminescence (PL) characterization. The UVB emission is observed at 316 nm when UV excited by 274 nm. The second order emission are also observed in PL emission spectra at 612 nm and 627 nm. Energy band gap is found to be 5.81 eV by using Kubelka - Munk function. The UVB emission at 316 nm of Gd3+ doped materials are used as phototherapy lamp phosphor.

The dominant allele Aft induces a shift from flavonol to anthocyanin production in response to UV-B radiation in tomato fruit.

Science.gov (United States)

Catola, Stefano; Castagna, Antonella; Santin, Marco; Calvenzani, Valentina; Petroni, Katia; Mazzucato, Andrea; Ranieri, Annamaria

2017-08-01

The introgression of the A ft allele into domesticated tomato induced a shift from flavonol to anthocyanin production in response to UV-B radiation, while the hp - 1 allele negatively influenced the response of flavonoid biosynthesis to UV-B. Introgression of the dominant allele Anthocyanin fruit (Aft) from Solanum chilense induces anthocyanin accumulation in the peel of tomato (Solanum lycopersicum L.) fruit. UV-B radiation can influence plant secondary metabolism regulating the expression of several genes, among which those involved in flavonoid biosynthesis. Here, we investigated whether post-harvest UV-B treatment could up-regulate flavonoid production in tomato fruits and whether the Aft allele could affect flavonoid biosynthesis under UV-B radiation. Mature green fruits of an anthocyanin-rich tomato mutant line (SA206) and of its wild-type reference, cv. Roma, were daily subjected to post-harvest UV-B treatment until full ripening. Up-regulation of CHS and CHI transcription by UV-B treatment induced flavonoid accumulation in the peel of cv. Roma. Conversely, UV-B decreased the total flavonoid content and CHS transcript levels in the SA206 peel. SA206 being a double mutant containing also hp-1 allele, we investigated also the behavior of hp-1 fruit. The decreased peel flavonoid accumulation and gene transcription in response to UV-B suggest that hp-1 allele is involved in the marked down-regulation of the flavonoid biosynthesis observed in SA206 fruit. Interestingly, in SA206, UV-B radiation promoted the synthesis of delphinidin, petunidin, and malvidin by increasing F3'5'H and DFR transcription, but it decreased rutin production, suggesting a switch from flavonols to anthocyanins. Finally, although UV-B radiation does not reach the inner fruit tissues, it down-regulated flavonoid biosynthesis in the flesh of both genotypes. This study provides, for the first time, evidence that the presence of the functional Aft allele, under UV-B radiation, redirects

A Survey of the Potential Effects of Increasing UV-B Radiation on the Biosphere. Revision

National Research Council Canada - National Science Library

Martin, L

1998-01-01

..., and an increase in UV-B radiation at the surface of the Earth. An increase in UV-B on average would increase the incidence rate of non-melanoma skin cancer worldwide, with an unproved but likely increase in melanoma skin cancer...

Blackberry extract inhibits UVB-induced oxidative damage and inflammation through MAP kinases and NF-κB signaling pathways in SKH-1 mice skin

International Nuclear Information System (INIS)

Divya, Sasidharan Padmaja; Wang, Xin; Pratheeshkumar, Poyil; Son, Young-Ok; Roy, Ram Vinod; Kim, Donghern; Dai, Jin; Hitron, John Andrew; Wang, Lei; Asha, Padmaja; Shi, Xianglin; Zhang, Zhuo

2015-01-01

Extensive exposure of solar ultraviolet-B (UVB) radiation to skin induces oxidative stress and inflammation that play a crucial role in the induction of skin cancer. Photochemoprevention with natural products represents a simple but very effective strategy for the management of cutaneous neoplasia. In this study, we investigated whether blackberry extract (BBE) reduces chronic inflammatory responses induced by UVB irradiation in SKH-1 hairless mice skin. Mice were exposed to UVB radiation (100 mJ/cm 2 ) on alternate days for 10 weeks, and BBE (10% and 20%) was applied topically a day before UVB exposure. Our results show that BBE suppressed UVB-induced hyperplasia and reduced infiltration of inflammatory cells in the SKH-1 hairless mice skin. BBE treatment reduced glutathione (GSH) depletion, lipid peroxidation (LPO), and myeloperoxidase (MPO) in mouse skin by chronic UVB exposure. BBE significantly decreased the level of pro-inflammatory cytokines IL-6 and TNF-α in UVB-exposed skin. Likewise, UVB-induced inflammatory responses were diminished by BBE as observed by a remarkable reduction in the levels of phosphorylated MAP Kinases, Erk1/2, p38, JNK1/2 and MKK4. Furthermore, BBE also reduced inflammatory mediators such as cyclooxygenase-2 (COX-2), prostaglandin E 2 (PGE 2 ), and inducible nitric oxide synthase (iNOS) levels in UVB-exposed skin. Treatment with BBE inhibited UVB-induced nuclear translocation of NF-κB and degradation of IκBα in mouse skin. Immunohistochemistry analysis revealed that topical application of BBE inhibited the expression of 8-oxo-7, 8-dihydro-2′-deoxyguanosine (8-oxodG), cyclobutane pyrimidine dimers (CPD), proliferating cell nuclear antigen (PCNA), and cyclin D1 in UVB-exposed skin. Collectively, these data indicate that BBE protects from UVB-induced oxidative damage and inflammation by modulating MAP kinase and NF-κB signaling pathways. - Highlights: • Blackberry extract inhibits UVB-induced glutathione depletion. • Blackberry

Blackberry extract inhibits UVB-induced oxidative damage and inflammation through MAP kinases and NF-κB signaling pathways in SKH-1 mice skin

Energy Technology Data Exchange (ETDEWEB)

Divya, Sasidharan Padmaja; Wang, Xin; Pratheeshkumar, Poyil; Son, Young-Ok; Roy, Ram Vinod [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Department of Toxicology and Cancer Biology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Kim, Donghern; Dai, Jin [Department of Toxicology and Cancer Biology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Hitron, John Andrew; Wang, Lei [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Department of Toxicology and Cancer Biology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Asha, Padmaja [National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Cochin (India); Shi, Xianglin [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Department of Toxicology and Cancer Biology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Zhang, Zhuo, E-mail: zhuo.zhang@uky.edu [Department of Toxicology and Cancer Biology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States)

2015-04-01

Extensive exposure of solar ultraviolet-B (UVB) radiation to skin induces oxidative stress and inflammation that play a crucial role in the induction of skin cancer. Photochemoprevention with natural products represents a simple but very effective strategy for the management of cutaneous neoplasia. In this study, we investigated whether blackberry extract (BBE) reduces chronic inflammatory responses induced by UVB irradiation in SKH-1 hairless mice skin. Mice were exposed to UVB radiation (100 mJ/cm{sup 2}) on alternate days for 10 weeks, and BBE (10% and 20%) was applied topically a day before UVB exposure. Our results show that BBE suppressed UVB-induced hyperplasia and reduced infiltration of inflammatory cells in the SKH-1 hairless mice skin. BBE treatment reduced glutathione (GSH) depletion, lipid peroxidation (LPO), and myeloperoxidase (MPO) in mouse skin by chronic UVB exposure. BBE significantly decreased the level of pro-inflammatory cytokines IL-6 and TNF-α in UVB-exposed skin. Likewise, UVB-induced inflammatory responses were diminished by BBE as observed by a remarkable reduction in the levels of phosphorylated MAP Kinases, Erk1/2, p38, JNK1/2 and MKK4. Furthermore, BBE also reduced inflammatory mediators such as cyclooxygenase-2 (COX-2), prostaglandin E{sub 2} (PGE{sub 2}), and inducible nitric oxide synthase (iNOS) levels in UVB-exposed skin. Treatment with BBE inhibited UVB-induced nuclear translocation of NF-κB and degradation of IκBα in mouse skin. Immunohistochemistry analysis revealed that topical application of BBE inhibited the expression of 8-oxo-7, 8-dihydro-2′-deoxyguanosine (8-oxodG), cyclobutane pyrimidine dimers (CPD), proliferating cell nuclear antigen (PCNA), and cyclin D1 in UVB-exposed skin. Collectively, these data indicate that BBE protects from UVB-induced oxidative damage and inflammation by modulating MAP kinase and NF-κB signaling pathways. - Highlights: • Blackberry extract inhibits UVB-induced glutathione depletion. �

Ultra-violet B (UVB)-induced skin cell death occurs through a cyclophilin D intrinsic signaling pathway.

Science.gov (United States)

Ji, Chao; Yang, Bo; Yang, Zhi; Tu, Ying; Yang, Yan-li; He, Li; Bi, Zhi-Gang

2012-09-07

UVB-induced skin cell damage involves the opening of mitochondrial permeability transition pore (mPTP), which leads to both apoptotic and necrotic cell death. Cyclophilin D (Cyp-D) translocation to the inner membrane of mitochondrion acts as a key component to open the mPTP. Our Western-Blot results in primary cultured human skin keratinocytes and in HaCaT cell line demonstrated that UVB radiation and hydrogen peroxide (H(2)O(2)) induced Cyp-D expression, which was inhibited by anti-oxidant N-acetyl cysteine (NAC). We created a stable Cyp-D deficiency skin keratinocytes by expressing Cyp-D-shRNA through lentiviral infection. Cyp-D-deficient cells were significantly less susceptible than their counterparts to UVB- or H(2)O(2)-induced cell death. Further, cyclosporine A (Cs-A), a Cyp-D inhibitor, inhibited UVB- or H(2)O(2)-induced keratinocytes cell death. Reversely, over-expression of Cyp-D in primary keratinocytes caused spontaneous keratinocytes cell death. These results suggest Cyp-D's critical role in UVB/oxidative stress-induced skin cell death. Copyright © 2012 Elsevier Inc. All rights reserved.

UVA, UVB Light Doses and Harvesting Time Differentially Tailor Glucosinolate and Phenolic Profiles in Broccoli Sprouts.

Science.gov (United States)

Moreira-Rodríguez, Melissa; Nair, Vimal; Benavides, Jorge; Cisneros-Zevallos, Luis; Jacobo-Velázquez, Daniel A

2017-06-26

Broccoli sprouts contain health-promoting glucosinolate and phenolic compounds that can be enhanced by applying ultraviolet light (UV). Here, the effect of UVA or UVB radiation on glucosinolate and phenolic profiles was assessed in broccoli sprouts. Sprouts were exposed for 120 min to low intensity and high intensity UVA (UVA L , UVA H ) or UVB (UVB L , UVB H ) with UV intensity values of 3.16, 4.05, 2.28 and 3.34 W/m², respectively. Harvest occurred 2 or 24 h post-treatment; and methanol/water or ethanol/water (70%, v / v ) extracts were prepared. Seven glucosinolates and 22 phenolics were identified. Ethanol extracts showed higher levels of certain glucosinolates such as glucoraphanin, whereas methanol extracts showed slight higher levels of phenolics. The highest glucosinolate accumulation occurred 24 h after UVB H treatment, increasing 4-methoxy-glucobrassicin, glucobrassicin and glucoraphanin by ~170, 78 and 73%, respectively. Furthermore, UVA L radiation and harvest 2 h afterwards accumulated gallic acid hexoside I (~14%), 4- O -caffeoylquinic acid (~42%), gallic acid derivative (~48%) and 1-sinapoyl-2,2-diferulolyl-gentiobiose (~61%). Increases in sinapoyl malate (~12%), gallotannic acid (~48%) and 5-sinapoyl-quinic acid (~121%) were observed with UVB H Results indicate that UV-irradiated broccoli sprouts could be exploited as a functional food for fresh consumption or as a source of bioactive phytochemicals with potential industrial applications.

Nuclear DNA damage-triggered NLRP3 inflammasome activation promotes UVB-induced inflammatory responses in human keratinocytes

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Tatsuya, E-mail: tatsuya.hasegawa@to.shiseido.co.jp; Nakashima, Masaya; Suzuki, Yoshiharu

2016-08-26

Ultraviolet (UV) radiation in sunlight can result in DNA damage and an inflammatory reaction of the skin commonly known as sunburn, which in turn can lead to cutaneous tissue disorders. However, little has been known about how UV-induced DNA damage mediates the release of inflammatory mediators from keratinocytes. Here, we show that UVB radiation intensity-dependently increases NLRP3 gene expression and IL-1β production in human keratinocytes. Knockdown of NLRP3 with siRNA suppresses UVB-induced production of not only IL-1β, but also other inflammatory mediators, including IL-1α, IL-6, TNF-α, and PGE{sub 2}. In addition, inhibition of DNA damage repair by knockdown of XPA, which is a major component of the nucleotide excision repair system, causes accumulation of cyclobutane pyrimidine dimer (CPD) and activation of NLRP3 inflammasome. In vivo immunofluorescence analysis confirmed that NLRP3 expression is also elevated in UV-irradiated human epidermis. Overall, our findings indicate that UVB-induced DNA damage initiates NLRP3 inflammasome activation, leading to release of various inflammatory mediators from human keratinocytes. - Highlights: • UVB radiation induces NLRP3 inflammasome activation in human keratinocytes. • NLRP3 knockdown suppresses production of UVB-induced inflammatory mediators. • UVB-induced DNA damage triggers NLRP3 inflammasome activation. • NLRP3 expression in human epidermis is elevated in response to UV radiation.

Nuclear DNA damage-triggered NLRP3 inflammasome activation promotes UVB-induced inflammatory responses in human keratinocytes

International Nuclear Information System (INIS)

Hasegawa, Tatsuya; Nakashima, Masaya; Suzuki, Yoshiharu

2016-01-01

Ultraviolet (UV) radiation in sunlight can result in DNA damage and an inflammatory reaction of the skin commonly known as sunburn, which in turn can lead to cutaneous tissue disorders. However, little has been known about how UV-induced DNA damage mediates the release of inflammatory mediators from keratinocytes. Here, we show that UVB radiation intensity-dependently increases NLRP3 gene expression and IL-1β production in human keratinocytes. Knockdown of NLRP3 with siRNA suppresses UVB-induced production of not only IL-1β, but also other inflammatory mediators, including IL-1α, IL-6, TNF-α, and PGE_2. In addition, inhibition of DNA damage repair by knockdown of XPA, which is a major component of the nucleotide excision repair system, causes accumulation of cyclobutane pyrimidine dimer (CPD) and activation of NLRP3 inflammasome. In vivo immunofluorescence analysis confirmed that NLRP3 expression is also elevated in UV-irradiated human epidermis. Overall, our findings indicate that UVB-induced DNA damage initiates NLRP3 inflammasome activation, leading to release of various inflammatory mediators from human keratinocytes. - Highlights: • UVB radiation induces NLRP3 inflammasome activation in human keratinocytes. • NLRP3 knockdown suppresses production of UVB-induced inflammatory mediators. • UVB-induced DNA damage triggers NLRP3 inflammasome activation. • NLRP3 expression in human epidermis is elevated in response to UV radiation.

Separate and Combined Response to UV-B Radiation and Jasmonic Acid on Photosynthesis and Growth Characteristics of Scutellaria baicalensis

Directory of Open Access Journals (Sweden)

Jiaxin Quan

2018-04-01

Full Text Available The negative effects of enhanced ultraviolet-B (UV-B on plant growth and development have been reported with many species. Considering the ability of jasmonic acid (JA to improve plant stress tolerance, the hypothesis that JA pretreatment could alleviate the adverse effects of UV-B on S. baicalensis was tested in this study with photosynthesis and growth characteristics. The results showed that UV-B or JA alone both induced photosynthesis inhibition and decreased biomass in stems and leaves. However, the photosynthetic reduction caused by increased UV-B was mainly related to the effect of nonstomatal-limitation, while that of JA was a stomatal-limitation effect. JA pretreatment prior to UV-B could remit the photosynthetic inhibition via the recovery of chlorophyll content, stomatal conductance; and intercellular CO2 concentration (especially the maximum electron transport rate increase. Furthermore, the coaction of JA and enhanced UV-B alleviated some disadvantageous effects on the leaf and did not aggravate the growth damage induced by their separate actions.

Separate and Combined Response to UV-B Radiation and Jasmonic Acid on Photosynthesis and Growth Characteristics of Scutellaria baicalensis.

Science.gov (United States)

Quan, Jiaxin; Song, Shanshan; Abdulrashid, Kadir; Chai, Yongfu; Yue, Ming; Liu, Xiao

2018-04-13

The negative effects of enhanced ultraviolet-B (UV-B) on plant growth and development have been reported with many species. Considering the ability of jasmonic acid (JA) to improve plant stress tolerance, the hypothesis that JA pretreatment could alleviate the adverse effects of UV-B on S. baicalensis was tested in this study with photosynthesis and growth characteristics. The results showed that UV-B or JA alone both induced photosynthesis inhibition and decreased biomass in stems and leaves. However, the photosynthetic reduction caused by increased UV-B was mainly related to the effect of nonstomatal-limitation, while that of JA was a stomatal-limitation effect. JA pretreatment prior to UV-B could remit the photosynthetic inhibition via the recovery of chlorophyll content, stomatal conductance; and intercellular CO₂ concentration (especially the maximum electron transport rate increase). Furthermore, the coaction of JA and enhanced UV-B alleviated some disadvantageous effects on the leaf and did not aggravate the growth damage induced by their separate actions.

[Temperature sensitivity of wheat plant respiration and soil respiration influenced by increased UV-B radiation from elongation to flowering periods].

Science.gov (United States)

Chen, Shu-Tao; Hu, Zheng-Hua; Li, Han-Mao; Ji, Yu-Hong; Yang, Yan-Ping

2009-05-15

Field experiment was carried out in the spring of 2008 in order to investigate the effects of increased UV-B radiation on the temperature sensitivity of wheat plant respiration and soil respiration from elongation to flowering periods. Static chamber-gas chromatography method was used to measure ecosystem respiration and soil respiration under 20% UV-B radiation increase and control. Environmental factors such as temperature and moisture were also measured. Results indicated that supplemental UV-B radiation inhibited the ecosystem respiration and soil respiration from wheat elongation to flowering periods, and the inhibition effect was more obvious for soil respiration than for ecosystem respiration. Ecosystem respiration rates, on daily average, were 9%, 9%, 3%, 16% and 30% higher for control than for UV-B treatment forthe five measurement days, while soil respiration rates were 99%, 93%, 106%, 38% and 10% higher for control than for UV-B treatment. The Q10s (temperature sensitivity coefficients) for plant respiration under control and UV-B treatments were 1.79 and 1.59, respectively, while the Q10s for soil respiration were 1.38 and 1.76, respectively. The Q10s for ecosystem respiration were 1.65 and 1.63 under CK and UV-B treatments, respectively. Supplemental UV-B radiation caused a lower Q10 for plant respiration and a higher Q10 for soil respiration, although no significant effect of supplemental UV-B radiation on the Q10 for ecosystem respiration was found.

Molecular mechanisms of UVB-induced senescence of dermal fibroblasts and its relevance for photoaging of the human skin.

Science.gov (United States)

Cavinato, Maria; Jansen-Dürr, Pidder

2017-08-01

Due to its ability to cross the epidermis and reach the upper dermis where it causes cumulative DNA damage and increased oxidative stress, UVB is considered the most harmful component of sunlight to the skin. The consequences of chronic exposition to UVB are related to photoaging and photocarcinogenesis. There are limitations to the study of human skin aging and for this reason the use of models is required. Human dermal fibroblasts submitted to mild and repeated doses of UVB are considered a versatile model to study UVB effects in the process of skin photoaging, which depends on the accumulation of senescent cells, in particular in the dermis. Here we provide updated information about the current model of UVB-induced senescence with special emphasis on the process of protein quality control. Copyright © 2017 Elsevier Inc. All rights reserved.

Regulation of the expression of NADP-malic enzyme by UV-B, red and far-red light in maize seedlings

Directory of Open Access Journals (Sweden)

P. Casati

1999-10-01

Full Text Available The induction of nicotinamide adenine dinucleotide phosphate-malic enzyme (NADP-ME in etiolated maize (Zea mays seedlings by UV-B and UV-A radiation, and different levels of photosynthetically active radiation (PAR, 400-700 nm was investigated by measuring changes in activity, protein quantity and RNA levels as a function of intensity and duration of exposure to the different radiations. Under low levels of PAR, exposure to UV-B radiation but not UV-A radiation for 6 to 24 h caused a marked increase in the enzyme levels similar to that observed under high PAR in the absence of UV-B. UV-B treatment of green leaves following a 12-h dark period also caused an increase in NADP-ME expression. Exposure to UV-B radiation for only 5 min resulted in a rapid increase of the enzyme, followed by a more gradual rise with longer exposure up to 6 h. Low levels of red light for 5 min or 6 h were also effective in inducing NADP-ME activity equivalent to that obtained with UV-B radiation. A 5-min exposure to far-red light following UV-B or red light treatment reversed the induction of NADP-ME, and this effect could be eliminated by further treatment with UV-B or red light. These results indicate that physiological levels of UV-B radiation can have a positive effect on the induction of this photosynthetic enzyme. The reducing power and pyruvate generated by the activity of NADP-ME may be used for respiration, in cellular repair processes and as substrates for fatty acid synthesis required for membrane repair.

Effects of sodium nitroprusside (SNP) pretreatment on UV-B stress tolerance in lettuce (Lactuca sativa L.) seedlings.

Science.gov (United States)

Esringu, Aslıhan; Aksakal, Ozkan; Tabay, Dilruba; Kara, Ayse Aydan

2016-01-01

Ultraviolet-B (UV-B) radiation is one of the most important abiotic stress factors that could influence plant growth, development, and productivity. Nitric oxide (NO) is an important plant growth regulator involved in a wide variety of physiological processes. In the present study, the possibility of enhancing UV-B stress tolerance of lettuce seedlings by the exogenous application of sodium nitroprusside (SNP) was investigated. UV-B radiation increased the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and total phenolic concentrations, antioxidant capacity, and expression of phenylalanine ammonia lyase (PAL) gene in seedlings, but the combination of SNP pretreatment and UV-B enhanced antioxidant enzyme activities, total phenolic concentrations, antioxidant capacity, and PAL gene expression even more. Moreover, UV-B radiation significantly inhibited chlorophylls, carotenoid, gibberellic acid (GA), and indole-3-acetic acid (IAA) contents and increased the contents of abscisic acid (ABA), salicylic acid (SA), malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide radical (O2•(-)) in lettuce seedlings. When SNP pretreatment was combined with the UV-B radiation, we observed alleviated chlorophylls, carotenoid, GA, and IAA inhibition and decreased content of ABA, SA, MDA, H2O2, and O2•(-) in comparison to non-pretreated stressed seedlings.

[Effects of silicon supply on diurnal variations of physiological properties at rice heading stage under elevated UV-B radiation].

Science.gov (United States)

Wu, Lei; Lou, Yun-sheng; Meng, Yan; Wang, Wei-qing; Cui, He-yang

2015-01-01

A pot experiment was conducted to investigate the effects of silicon (Si) supply on diurnal variations of photosynthesis and transpiration-related physiological parameters at rice heading stage under elevated UV-B radiation. The experiment was designed with two UV-B radiation levels, i.e. ambient UV-B. (ambient, A) and elevated UV-B (elevated by 20%, E), and four Si supply levels, i.e. Sio (control, 0 kg SiO2 . hm-2), Si, (sodium silicate, 100 kg SiO2 . hm-2), Si2 (sodium silicate, 200 kg SiO2 . hm2), Si3 (slag fertilizer, 200 kg SiO2 . hm-2). The results showed that, compared with ambient UV-B radiation, elevated UV-B radiation decreased the net photosynthesis rate (Pn) , intercellular CO2 concentration (Ci), transpiration rate (Tr), stomatal conductivity (gs) and water use efficiency (WUE) by 11.3%, 5.5%, 10.4%, 20.3% and 6.3%, respectively, in the treatment without Si supply (Si, level), and decreased the above parameters by 3.8%-5.5%, 0.7%-4.8%, 4.0%-8.7%, 7.4%-20.2% and 0.7%-5.9% in the treatments with Si supply (Si1, Si2 and Si3 levels) , respectively. Namely, elevated UV-B radiation decreased the photosynthesis and transpiration-related physiological parameters, but silicon supply could obviously mitigate the depressive effects of elevated UV-B radiation. Under elevated UV-B radiation, compared with control (Si0 level), silicon supply increased Pn, Ci, gs and WUE by 16.9%-28.0%, 3.5%-14.3%, 16.8% - 38.7% and 29.0% - 51.2%, respectively, but decreased Tr by 1.9% - 10.8% in the treatments with Si supply (Si1 , Si2 and Si3 levels). That is, silicon supply could mitigate the depressive effects of elevated UV-B radiation through significantly increasingnP., CigsgK and WUE, but decreasing T,. However, the difference existed in ameliorating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among the treatments of silicon supply, with the sequence of Si3>Si2>1i >Si0. This study suggested that fertilizing slag was

Implications of mycosporine-like amino acid and antioxidant defenses in UV-B radiation tolerance for the algae species Ptercladiella capillacea and Gelidium amansii.

Science.gov (United States)

Lee, Tse-Min; Shiu, Chia-Tai

2009-02-01

Ultraviolet-B (UV-B) radiation (0.5, 1.0, 1.5, and 3.0Wm(-2)) induced higher H(2)O(2) production and lipid peroxidation in alga Gelidium amansii inhabiting in lower subtidal regions than upper subtidal alga Ptercladiella capillacea. Compared to G. amansii, mycosporine-like amino acid (MAA) concentration in P. capillacea was higher and can be increased by 0.5-1.0Wm(-2) UV-B, while carotenoid concentration was lower but also increased by 1.5-3.0Wm(-2) UV-B. UV-B increased ascorbate concentration, but to a higher degree in P. capillacea. UV-B decreased glutathione concentration, but to a higher degree in G. amansii. UV-B increased ascorbate peroxidase (APX) and glutathione reductase (GR) activities in P.capillacea but decreased them in G. amansii. UV-B increased superoxide dismutase and catalase activities, but to a higher degree in G. amansii. So, G. amansii suffered greater oxidative stress from UV-B radiation. P. capillacea can effectively reduce UV-B sensitivity by increasing sunscreen ability and antioxidant defense capacity.

Higher plants and UV-B radiation: balancing damage, repair and acclimation

International Nuclear Information System (INIS)

Jansen, M.A.K.; Gaba, V.; Greenberg, B.M.

1998-01-01

Although UV-B is a minor component of sunlight, it has a disproportionately damaging effect on higher plants. Ultraviolet-sensitive targets include DNA, proteins and membranes, and these must be protected for normal growth and development. DNA repair and secondary metabolite accumulation during exposure to UV-B have been characterized in considerable detail, but little is known about the recovery of photosynthesis, induction of free-radical scavenging and morphogenic changes. A future challenge is to elucidate how UV-B-exposed plants balance damage, repair, acclimation and adaptation responses in a photobiologically dynamic environment. (author)

The effects of altered levels of UV-B radiation on an Antarctic grass and lichen

NARCIS (Netherlands)

Lud, D.; Huiskes, A.H.L.; Moerdijk-Poortvliet, T.C.W.; Rozema, J.J.

2001-01-01

We report a long-term experiment on the photosynthetic response of natural vegetation of Deschampsia antarctica (Poaceae) and Turgidosculum complicatulum (Lichenes) to altered UV-B levels on Leonie Island, Antarctica. UV-B above the vegetation was reduced by filter screens during two seasons. Half

Increase of vitamin D2 by UV-B exposure during the growth phase of white button mushroom (Agaricus bisporus

Directory of Open Access Journals (Sweden)

Hanne L. Kristensen

2012-04-01

Full Text Available Background: Mushrooms are the only non-animal food source of vitamin D. Wild mushrooms have naturally high vitamin D2 content, and cultivated mushrooms produce vitamin D2 from ergosterol when exposed to supplementary UV-B during the post-harvest phase.Objectives: This study investigated the effects of providing supplementary UV-B during the growth phase on vitamin D2 formation and the interactions with growth of mushrooms, as compared to supplementary UV-B during the post-harvest phase or exposure to sunlight for both cultivated and wild mushrooms.Methods: Experiments were carried out with exposure to supplementary UV-B just prior to harvest in the range of 0–2,400 mJ cm−2. Mushrooms grew for 2 days with or without repeated UV-B exposure each day. Vitamin D2 and growth rate were determined. In addition, some mushrooms were post-harvest treated by exposure at 200 mJ cm−2 supplementary UV-B or natural sunlight, prior to vitamin D2 determination.Results: The content of vitamin D2 was 0.2–164 µg 100 g−1 fresh weight, and there was a linear relationship between UV-dose up to 1,000 mJ cm−2 and vitamin D2 content. The fast growth rate of the mushrooms diluted the vitamin D2 from 24 to 3 µg 100 g−1 within 2 days of exposure at 200 mJ cm−2. Following repeated UV-B exposure, vitamin D2 increased to 33 µg vitamin D2 100 g−1. Growth was unaffected by UV-B. Post-harvest exposure to supplementary UV-B resulted in a higher vitamin D2 content of 32 µg 100 g−1 compared to the 24 µg 100 g−1 obtained from exposure to UV-B during the growth phase. In contrast, wild and cultivated mushrooms with and without exposure to sunlight had vitamin D2 content in the range of 0.2–1.5 µg vitamin D2 100 g−1.Conclusions: This study showed that mushrooms with a well-defined content of vitamin D2 can be obtained by exposure to supplementary UV-B just prior to harvest.

Inhibitory effects of ambient levels of solar UV-A and UV-B radiation in growth of cv. New Red Fire lettuce

International Nuclear Information System (INIS)

Krizek, D.T.; Britz, S.J.; Mirecki, R.M.

1998-01-01

The influence of solar UV-A and UV-B radiation at Beltsville, MD, USA, on growth of Lactuca sativa L. (cv. New Red Fire lettuce) was examined during early summer of 1996 and 1997. Plants were grown from seed in plastic window boxes covered with Llumar to exclude UV-A and UV-B, polyester to exclude UV-B, or tefzel (1996) or teflon (1997) to transmit UV-A and UV-B radiation. After 31-34 days, plants grown in the absence of solar UV-B radiation (polyester) had 63 and 57% greater fresh weight and dry weight of tops, respectively, and 57, 72 and 47% greater dry weight of leaves, stems and roots, respectively, as compared to those grown under ambient UV-B (tefzel or teflon). Plants protected from UV-A radiation as well (Llumar) showed an additional 43 and 35% increase, respectively, in fresh and dry weight of tops and a 33 and 33% increase, respectively, in dry weight of leaves and stems, but no difference in root biomass over those grown under polyester. Excluding ambient UV-B (polyester) significantly reduced the UV absorbance of leaf extracts at 270, 300 and 330 nm (presumptive flavonoids) and the concentration of anthocyantins at 550 nm as compared to those of leaf extract from plants grown under ambient UV-A and UV-B. Additional removal of ambient UV-A (Llumar) reduced the concentration of anthocyanins, but had no further effect on UV absorbance at 270, 300 or 330 nm. These findings provide evidence that UV-B radiation is more important than UV-A radiation for flavonoid induction in this red-pigmented lettuce cultivar. Although previous workers have obtained decreases in lettuce yield under enhanced UV-B, this is the first evidence for inhibitory effects of solar UV-A and UV-B radiation on lettuce growth. (au)

Inhibitory effects of ambient levels of solar UV-A and UV-B radiation in growth of cv. New Red Fire lettuce

Energy Technology Data Exchange (ETDEWEB)

Krizek, D.T.; Britz, S.J.; Mirecki, R.M. [Climate Stress Laboratory, Beltsville, MD (United States)

1998-05-01

The influence of solar UV-A and UV-B radiation at Beltsville, MD, USA, on growth of Lactuca sativa L. (cv. New Red Fire lettuce) was examined during early summer of 1996 and 1997. Plants were grown from seed in plastic window boxes covered with Llumar to exclude UV-A and UV-B, polyester to exclude UV-B, or tefzel (1996) or teflon (1997) to transmit UV-A and UV-B radiation. After 31-34 days, plants grown in the absence of solar UV-B radiation (polyester) had 63 and 57% greater fresh weight and dry weight of tops, respectively, and 57, 72 and 47% greater dry weight of leaves, stems and roots, respectively, as compared to those grown under ambient UV-B (tefzel or teflon). Plants protected from UV-A radiation as well (Llumar) showed an additional 43 and 35% increase, respectively, in fresh and dry weight of tops and a 33 and 33% increase, respectively, in dry weight of leaves and stems, but no difference in root biomass over those grown under polyester. Excluding ambient UV-B (polyester) significantly reduced the UV absorbance of leaf extracts at 270, 300 and 330 nm (presumptive flavonoids) and the concentration of anthocyantins at 550 nm as compared to those of leaf extract from plants grown under ambient UV-A and UV-B. Additional removal of ambient UV-A (Llumar) reduced the concentration of anthocyanins, but had no further effect on UV absorbance at 270, 300 or 330 nm. These findings provide evidence that UV-B radiation is more important than UV-A radiation for flavonoid induction in this red-pigmented lettuce cultivar. Although previous workers have obtained decreases in lettuce yield under enhanced UV-B, this is the first evidence for inhibitory effects of solar UV-A and UV-B radiation on lettuce growth. (au) 34 refs.

Sensitivity of two ecotypes of Arabidopsis Thaliana (Cvi and Te) towards UV-B irradiation

International Nuclear Information System (INIS)

Velichkova, M.; Stanoeva, D.; Popova, A.

2013-01-01

he susceptibility of Arabidopsis thaliana towards the detrimental effect of UV-B irradiation was investigated using two ecotypes, Cvi and Te. The effect of UV-B treatment on primary photosynthetic reactions - energy interaction between the main pigment-protein complexes and oxygen evolution, was evaluated at low (4 0 C) and at room (22 0 C) temperature. UV-B-induced alterations of investigated photosynthetic reactions are better expressed at 22 0 C than at 4 0 C for Cvi. For Te ecotype the energy interaction was suppressed to higher extent at 22 0 C, while oxygen evolving activity was affected similarly at both temperatures. At low and room temperature, the energy interaction in the complex PSII-core antenna is affected stronger by UV-B treatment than the energy distribution between both photosystems, as revealed by fluorescence ratios of 77 K spectra. The results presented indicate that the Arabidopsis thaliana ecotype Cvi (Cape Verde Islands) is less affected by UV-B irradiation in respect to the investigated primary photosynthetic reactions than the ecotype Te (Finland)

Quantitation of pyrimidine dimers in DNA from UVB-irradiated alfalfa (Medicago sativa L.) seedlings

International Nuclear Information System (INIS)

Quaite, F.E.; Sutherland, B.M.; Sutherland, J.C.

1991-01-01

Depletion of stratospheric ozone will increase the solar ultraviolet radiation in the range from 290-320 nm (UVB) that reaches the surface of the earth, placing an increased UV burden on exposed organisms. One consequence of increased UVB may be decreased productivity of crop plants. A principal lesion caused by UV in DNA is the cyclobutyl pyrimidine dimer. We have adapted a method for measuring these dimers in nanogram quantities of non-radioactive DNA for use in UV-irradiated plants. We find that biologically relevant doses of broad band UVB radiation induce easily detectable frequencies of pyrimidine dimers in the DNA of irradiated alfalfa sprout leaves and that the dose response for dimer formation is linear up to doses of at least 690 J/m 2 . We also find easily measurable frequencies of dimers in the leaves of seedlings grown in glass filtered sunlight but not exposed to additional UVB, suggesting that significant number of dimers are formed in plants exposed to normal sunlight. 27 refs., 3 figs., 1 tab

The influence of urban area opacity on biologically active UV-B irradiance

Science.gov (United States)

Chubarova, Nataly; Rozental', Victor

2013-04-01

The study of UV irradiance changes in urban area is an essential problem due to the significant effect of UV irradiance on human health which can be positive (vitamin D synthesis) and negative (erythema, skin cancer, eye damage). According to the results of several experiments within the Moscow megacity we studied the effects of urban area opacity on the different types of biologically active UV-B irradiance on the base of a specially developed mobile photometric complex snd additional measurements of the urban opacity by Nikon Fisheye Converter FC-E8. We analyzed both the level of erythemally-active irradiance and the UV eye damaging radiation using the broadband UVB-1 YES pyranometer calibrated against ultraviolet spectroradiometer Bentham DTM-300 of the Medical University of Innsbruck (courtesy of Dr. M.Blumthaler). In order to estimate the effects of the urban opacity the measurements were normalized on similar measurements at the Meteorological Observatory of Moscow State University with zero opacity. This ratio is defined as an urban radiative transmittance (URT). Different atmospheric conditions were considered. In cloudy conditions the effect of opacity on URT is much less than that in conditions when the sun disk is open from clouds. We revealed some spectral features in transmittance of biologically active UV-B irradiance which is characterized by higher URT variations in overcast cloudy conditions due to more intensive scattering and smaller direct solar radiation component. In the absence of cloudiness the effect of opacity was studied for open and screening solar disk conditions. We obtained much higher URT in UVB spectral region compared with that for total solar irradiance for screening solar disk conditions with a significant URT dependence on the opacity only in UVB spectral region. No URT dependence was obtained for total solar irradiance in these conditions. Some model calculations were fulfilled to match the experimental results.

Xanthophylls and alpha-tocopherol decrease UVB-induced lipid peroxidation and stress signaling in human lens epithelial cells.

Science.gov (United States)

Chitchumroonchokchai, Chureeporn; Bomser, Joshua A; Glamm, Jayme E; Failla, Mark L

2004-12-01

Epidemiological studies suggest that consumption of vegetables rich in the xanthophylls lutein (LUT) and zeaxanthin (ZEA) reduces the risk for developing age-related cataract, a leading cause of vision loss. Although LUT and ZEA are the only dietary carotenoids present in the lens, direct evidence for their photoprotective effect in this organ is not available. The present study examined the effects of xanthophylls and alpha-tocopherol (alpha-TC) on lipid peroxidation and the mitogen-activated stress signaling pathways in human lens epithelial (HLE) cells following ultraviolet B light (UVB) irradiation. When presented with LUT, ZEA, astaxanthin (AST), and alpha-TC as methyl-beta-cyclodextrin complexes, HLE cells accumulated the lipophiles in a concentration- and time-dependent manner with uptake of LUT exceeding that of ZEA and AST. Pretreatment of cultures with either 2 micromol/L xanthophyll or 10 micromol/L alpha-TC for 4 h before exposure to 300 J/m(2) UVB radiation decreased lipid peroxidation by 47-57% compared with UVB-treated control HLE cells. Pretreatment with the xanthophylls and alpha-TC also inhibited UVB-induced activation of c-JUN NH(2)-terminal kinase (JNK) and p38 by 50-60 and 25-32%, respectively. There was substantial inhibition of UVB-induced JNK and p38 activation for cells containing xanthophylls/mg, respectively, whereas >2.3 nmol alpha-TC/mg protein was required to significantly decrease UVB-induced stress signaling. These data suggest that xanthophylls are more potent than alpha-TC for protecting human lens epithelial cells against UVB insult.

Elevated UV-B radiation increased the decomposition of Cinnamomum camphora and Cyclobalanopsis glauca leaf litter in subtropical China

Energy Technology Data Exchange (ETDEWEB)

Song, Xinzhang Z.; Zhang, Huiling L.; Jiang, Hong; Yu, Shuquan Q. [Zhejiang Agriculture and Forestry Univ., Lin' an (China). The Nurturing Station for the State Key Lab. of Subtropical Silviculture; Zhejiang Agriculture and Forestry Univ., Lin' an (China). Zhejiang Provincial Key Lab. of Carbon Cycling and Carbon Sequestration in Forest Ecosystems; Chang, Scott X. [Alberta Univ., Edmonton (Canada). Dept. of Renewable Resources; Peng, Changhui H. [Quebec Univ., Montreal (Canada). Inst. of Environment Sciences

2012-03-15

Ultraviolet-B (UV-B) radiation reaching the earth's surface has been increasing due to ozone depletion and can profoundly influence litter decomposition and nutrient cycling in terrestrial ecosystems. The role of UV-B radiation in litter decomposition in humid environments is poorly understood; we thus investigated the effect of UV-B radiation on litter decomposition and nitrogen (N) release in a humid subtropical ecosystem in China. We conducted a field-based experiment using the litterbag method to study litter decomposition and N release under ambient and elevated (31% above ambient) UV-B radiation, using the leaf litter of two common tree species, Cinnamomum camphora and Cyclobalanopsis glauca, native to subtropical China. Elevated UV-B radiation significantly increased the decomposition rate of C. camphora and C. glauca leaf litter by 16.7% and 27.8%, respectively, and increased the N release from the decomposing litter of C. glauca but not C. camphora. Elevated UV-B radiation significantly accelerated the decomposition of litter of two native tree species and the N release from the decomposition litter of C. glauca in humid subtropical China, which has implications for soil carbon flux and forest productivity. (orig.)

Repeated exposure to enhanced UV-B radiation in successive generations increases developmental instability (leaf fluctuating asymmetry) in a desert annual

International Nuclear Information System (INIS)

Midgley, G.F.; Wand, S.J.E.; Musil, C.F.

1998-01-01

Populations of the desert annual Dimorphotheca sinuata, derived from a common seed stock, were exposed concurrently over four successive generations to either ambient (representing no stratospheric ozone depletion) or elevated (representing 20% stratospheric ozone depletion) UV-B levels during their complete life cycle. Leaf fluctuating asymmetry (FA) was measured in populations of plants grown from seeds of selected generations which had experienced different UV-B exposure histories, and from seeds collected from a wild population of this species which grows in a naturally enhanced UV-B environment. These measured plants had been grown in a greenhouse under essentially UV-B-free conditions. Leaf FA was significantly increased by greater numbers of enhanced UV-B exposures in the parentage of the seed. There was a linear to exponential dose–response relationship between number of UV-B exposure iterations in seed parentage and leaf FA, suggesting that damage to DNA caused by UV-B exposure during plant development may not be fully repaired, and thus be inherited by offspring and accumulated over successive generations in this species. Leaf FA of plants grown from seed from the wild population was not significantly greater than that of control plants whose parentage experienced only ambient UV-B exposures, although this negative result may have been due to low sampling intensity and measurement resolution, and the relatively low UV-B enhancement experienced by the wild population. We conclude that leaf FA may constitute a relatively sensitive yet inexpensive means of quantifying UV-B damage to plants. (author)

Raman spectroscopic analysis of the responds of desert cyanobacterium Nostoc sp under UV-B radiation

Science.gov (United States)

Wang, Gaohong; Hao, Zongjie; Hu, Chunxiang; Liu, Yongding

Cyanobacteria are renowned for tolerating extremes of desiccation, UV radiation, freezethaw cycles, hypersalinity and oligotrophy, which make them as candidate par excellence for terraforming in extraterrestrial planet. Recently Raman spectrum was applied to study the biochemical information changes in different field of life science. In this study, we investigated the respond of desert cyanobactreium Nostoc sp under UV-B radiation via FT-Raman spectra. It was found that the spectral biomarkers of protectant molecular of UV radiation such as β-carotene and scytonemin were induced by UV-B radiation, but Chlorophyll a content was decreased, and also the photosynthesis activity was inhibited significantly. After light adaptation without UV-B radiation, the Chlorophyll a content and photosynthesis activity returned to high level, butβ-carotene and scytonemin content remained in the cells. Those results indicated that desert Cyanobacteria have good adaptation ability for UV-B radiation and synthesis of protectant molecular may be an effective strategy for its adaptation in evolution.

PUVA therapy is preferable to UVB phototherapy in the management of HIV-associated dermatoses

Energy Technology Data Exchange (ETDEWEB)

Morison, W.L. [Johns Hopkins Univ., Baltimore, MD (United States)

1996-08-01

Both methoxsalen plus UVA (PUVA) therapy and UVB phototherapy are commonly used in the management of human immunodeficiency virus-associated dermatoses but UVB phototherapy appears to be the preferred treatment. There are several considerations, in particular therapeutic efficacy and therapeutic profile, which suggest that PUVA therapy might be more effective. This needs to be established in clinical trials. (Author).

Combined effects of enhanced UV-B radiation and nitrogen deficiency on the growth, composition and photosynthesis of rye (Secale cereale)

International Nuclear Information System (INIS)

Deckmyn, G.; Impens, I.

1997-01-01

The interactive effects of N-deficiency and enhanced UV-B radiation on growth, photosynthesis and pigmentation of rye were studied. The plants were grown for 5 weeks in growth chambers with high (700 μmol m -2 s -2 ) irradiance levels. A 30% difference in UV-B at plant level was achieved by using different thicknesses of UV-B transparent Plexiglass. One half of the plants received optimal N nutrition, while the other received half of this dose. Both enhanced UV-B and N deficiency strongly decreased production (from 24–33%). The combined effect was additive (no interaction) on most parameters, including total dry weight production which was 52% lower than in the control series. Significant interaction was found on the root/shoot ratio. While reduced N supply induced an increase in the ratio at normal UV-B irradiation, under the increased UV-B, N deficiency had no effect on the root/shoot ratio. The reduced biomass due to UV-B was clearly correlated to a reduction in photosynthesis. At optimal N supply the plants increased the production of protective pigments in response to UV-B, but at reduced N supply this response was lacking. The increased N content of the high UV-B/high N plants could be a result of increased flavonoid production as well as changes in light penetration in the canopy. (author)

Morphological and physiological responses of two varieties of a highland species (Chenopodium quinoa Willd.) growing under near-ambient and strongly reduced solar UV-B in a lowland location.

Science.gov (United States)

González, Juan A; Rosa, Mariana; Parrado, María F; Hilal, Mirna; Prado, Fernando E

2009-08-03

Morphological and physiological responses of seedlings to different solar UV-B irradiances were evaluated in two varieties of quinoa (Chenopodium quinoa Willd.), a crop species from Andean region of South America. Cristalina and Chucapaca varieties were grown at 1965m a.s.l in a glasshouse under natural light conditions for 18 days, and then transferred to outdoors under near-ambient (+UV-B) and strongly reduced (-UV-B) solar UV-B radiation. Exposition to -UV-B increased cotyledon area and seedling height in Cristalina variety whereas leaf number decreased compared to +UV-B. By contrast Chucapaca variety was not affected by UV-B treatments. Seedling fresh weight (FW), root length and leaf thickness did not show significant differences between +UV-B and -UV-B treatments. Mesophyll tissue was slightly affected by solar UV-B reduction. Chlorophyll content was differentially affected by UV-B treatments. Under +UV-B the highest value was observed in Cristalina variety, while in Chucapaca it was observed under -UV-B treatment. Chlorophyll content was slightly higher in leaves than in cotyledons, but there was no difference in the distribution pattern. Chlorophyll a/b ratio and carotenoid content did not show significant differences between UV-B treatments. Leaf UVB-absorbing compounds showed significant differences between UV-B treatments in Chucapaca only, while there were no significant differences in Cristalina variety. UVB-absorbing compounds of cotyledons did not show significant differences between +UV-B and -UV-B treatments. Sucrose, glucose and fructose showed different distribution patterns in cotyledons and leaves of the two varieties under near-ambient and strongly reduced UV-B. Results demonstrated that varieties of quinoa exhibit different morphological and physiological responses to changes in solar UV-B irradiance, but these responses cannot be used to predict the sensitivity to solar UV-B during a short-term exposition. Also, this study can be useful to

Elevated UV-B radiation incident on Quercus robur leaf canopies enhances decomposition of resulting leaf litter in soil

International Nuclear Information System (INIS)

Newsham, K.K.; Greenslade, P.D.; Kennedy, V.H.; McLeod, A.R.

1999-01-01

We examined whether the exposure of Quercus robur L. to elevated UV-B radiation (280–315 nm) during growth would influence leaf decomposition rate through effects on litter quality. Saplings were exposed for eight months at an outdoor facility in the UK to a 30% elevation above the ambient level of erythemally weighted UV-B radiation under UV-B treatment arrays of fluorescent lamps filtered with cellulose diacetate, which transmitted both UV-B and UV-A (315–400 nm) radiation. Saplings were exposed to elevated UV-A alone under control arrays of lamps filtered with polyester and to ambient radiation under unenergised arrays of lamps. Abscised leaves from saplings were enclosed in 1 mm2 mesh nylon bags, placed in a Quercus–Fraxinus woodland and were sampled at 0.11, 0.53, 1.10 and 1.33 years for dry weight loss, chemical composition and saprotrophic fungal colonization. At abscission, litters from UV-A control arrays had ≈ 7.5% higher lignin/nitrogen ratios than those from UV-B treatment and ambient arrays (P < 0.06). Dry weight loss of leaves treated with elevated UV-B radiation during growth was 2.5% and 5% greater than that of leaves from UV-A control arrays at 0.53 and 1.33 years, respectively. Litter samples from UV-B treatment arrays lost more nitrogen and phosphorus than samples from ambient arrays and more carbon than samples from UV-A control arrays. The annual fractional weight loss of litter from UV-B treatment arrays was 8% and 6% greater than that of litter from UV-A control and ambient arrays, respectively. Regression analyses indicated that the increased decomposition rate of UV-B treated litters was associated with enhanced colonization of leaves by basidiomycete fungi, the most active members of the soil fungal community, and that the frequency of these fungi was negatively associated with the initial lignin/nitrogen ratio of leaves. (author)

Comparison of Solar UVA and UVB Radiation Measured in Selangor, Malaysia

International Nuclear Information System (INIS)

Kamarudin, S. U.; Gopir, G.; Yatim, B.; Sanusi, H.; Mahmud, P. S. Megat; Choo, P. Y.

2010-01-01

The solar ultraviolet A (UVA) radiation data was measured at Physics Building, Universiti Kebangsaan Malaysia (2 degree sign 55' N, 101 degree sign 46' E, 50m asl) by the Xplorer GLX Pasco that connected to UVA Light sensor. The measured solar UVA data were compared with the total daily solar ultraviolet B (UVB) radiation data recorded by the Malaysian Metrological Department at Petaling Jaya, Malaysia (3 degree sign 06' N, 101 degree sign 39' E, 50m asl) for 18 days in year 2007. The daily total average of UVA radiation received is (298±105) kJm -2 while the total daily maximum is (600±56) kJm -2 . From the analysis, it shows that the values of UVA radiation data were higher than UVB radiation data with the average ratio of 6.41% between 3-14%. A weak positive correlation was found (the correlation coefficient, r, is 0.22). The amount of UVA radiation that reached the earth surface is less dependence on UVB radiation and the factors were discussed.

Experimental assessment of cumulative temperature and UV-B radiation effects on Mediterranean plankton metabolism

Directory of Open Access Journals (Sweden)

Lara S. eGarcia-Corral

2015-07-01

Full Text Available The Mediterranean Sea is a vulnerable region for climate change, warming at higher rates compare to the global ocean. Warming leads to increased stratification of the water column and enhanced the oligotrophic nature of the Mediterranean Sea. The oligotrophic waters are already highly transparent, however, exposure of Mediterranean plankton to ultraviolet radiation (UV-B and UV-A may increase further if the waters become more oligotrophic, thereby, allowing a deeper UV radiation penetration and likely enhancing impacts to biota.Here we experimentally elucidate the cumulative effects of warming and natural UV-B radiation on the net community production (NCP of plankton communities. We conducted five experiments at monthly intervals, from June to October 2013, and evaluated the responses of NCP to ambient UV-B radiation and warming (+3ºC, alone and in combination, in a coastal area of the northwest Mediterranean Sea. UV-B radiation and warming lead to reduced net community production and resulted in a heterotrophic (NCP<0 metabolic balance. Both UV-B radiation and temperature, showed a significant individual effect in NCP across treatments and time. However, their joint effect showed to be synergistic as the interaction between them (UV x Temp was statistically significant in most of the experiments performed. Our results showed that both drivers, would affect the gas exchange of CO2-O2 from and to the atmosphere and the role of plankton communities in the Mediterranean carbon cycle

Experimental assessment of cumulative temperature and UV-B radiation effects on Mediterranean plankton metabolism

KAUST Repository

Garcia-Corral, Lara S.

2015-07-07

The Mediterranean Sea is a vulnerable region for climate change, warming at higher rates compare to the global ocean. Warming leads to increased stratification of the water column and enhanced the oligotrophic nature of the Mediterranean Sea. The oligotrophic waters are already highly transparent, however, exposure of Mediterranean plankton to ultraviolet radiation (UV-B and UV-A) may increase further if the waters become more oligotrophic, thereby, allowing a deeper UV radiation penetration and likely enhancing impacts to biota. Here we experimentally elucidate the cumulative effects of warming and natural UV-B radiation on the net community production (NCP) of plankton communities. We conducted five experiments at monthly intervals, from June to October 2013, and evaluated the responses of NCP to ambient UV-B radiation and warming (+3°C), alone and in combination, in a coastal area of the northwest Mediterranean Sea. UV-B radiation and warming lead to reduced NCP and resulted in a heterotrophic (NCP < 0) metabolic balance. Both UV-B radiation and temperature, showed a significant individual effect in NCP across treatments and time. However, their joint effect showed to be synergistic as the interaction between them (UV × Temp) was statistically significant in most of the experiments performed. Our results showed that both drivers, would affect the gas exchange of CO2−O2 from and to the atmosphere and the role of plankton communities in the Mediterranean carbon cycle.

Cyclobutyl pyrimidine dimer accumulation in relation to UV-B sensitivity in mung bean cultivars

International Nuclear Information System (INIS)

He Junmin; Wang Ruibin; Meng Zhaoni

2006-01-01

The purpose of the experiment is to reveal the relationship between cyclobutyl pyrimidine dimers (CPDs) accumulation and UV-B sensitivity in mung bean cultivars. Two mung bean cultivars (Phaseolus raditus L. cv. Qindou -2 0 and Zhonglü -1 ) were grown in greenhouse with treatment or without treatment of UV-B radiation (0.4 W * m -2 ) for four days. The UV-B-induced CPDs in mung bean DNA were quantified by enzyme-linked immunosorbent assay (ELISA) with specific monoclonal antibody and the relationship between CPDs accumulation and the UV-B sensitivity of mung bean seedlings were discussed. The UV-B-induced inhibition of the biomass and net photosynthetic rate of the primary leaves of cultivar Zhonglü -1 were respectively lower than that of cultivar Qindou -2 0, so that the cultivar Zhonglü -1 was more tolerant to UV-B than the cultivar Qindou -2 0. Meanwhile, the cultivar Zhonglü -1 had lower CPD accumulation and susceptibility to CPD induction, higher photorepair capacity and same dark repair capacity as compared with the cultivar Qindou -2 0. Different UV-B sensitivities between two mung bean cultivars may be mainly caused by the differences in CPD accumulation, which are caused by the different susceptibility to CPD induction and the different photorepair capacities. In addition, the different susceptibility to CPD induction between two mung bean cultivars is related to the different levels of UV-absorbing compounds

UVB-activated psoralen reduces luminal narrowing after balloon dilation because of inhibition of constrictive remodeling

NARCIS (Netherlands)

Perrée, Jop; van Leeuwen, Ton G.; Velema, Evelyn; Smeets, Mirjam; de Kleijn, Dominique; Borst, Cornelius

2002-01-01

In this study we have explored the potential of PUVB (8-MOP + UVB) therapy for the reduction of luminal narrowing after arterial injury. In 15 rabbits, balloon dilation of iliac arteries was performed. In 20 arteries, dilation was combined with the delivery of pulsed ultraviolet light B (UVB)

Increased UV-B radiation reduces N2-fixation in tropical leguminous crops

International Nuclear Information System (INIS)

Anupa Singh

1997-01-01

Net photosynthesis, leaf area, biomass, and number, size and activity of nodules were examined in three leguminous plants subjected under field conditions to supplemental UV-B radiation equivalent to a 15% ozone depletion at 25 degrees N latitude. Enhanced UV-B radiation adversely affected the net photosynthetic rate, growth characteristics and nodule activity in all three species. Maximum reduction in net photosynthesis occurred in Phaseolus mungo cv. Pant U-30, whereas the greatest reduction in nitrogenase activity occurred in Vigna radiata. (author)

Photoprotective Properties of Isothiocyanate and Nitrile Glucosinolate Derivatives From Meadowfoam (Limnanthes alba Against UVB Irradiation in Human Skin Equivalent

Directory of Open Access Journals (Sweden)

Evan L. Carpenter

2018-05-01

Full Text Available Exposure to ultraviolet B (UVB irradiation of the skin leads to numerous dermatological concerns including skin cancer and accelerated aging. Natural product glucosinolate derivatives, like sulforaphane, have been shown to exhibit chemopreventive and photoprotective properties. In this study, we examined meadowfoam (Limnanthes alba glucosinolate derivatives, 3-methoxybenzyl isothiocyanate (MBITC and 3-methoxyphenyl acetonitrile (MPACN, for their activity in protecting against the consequences of UV exposure. To that end, we have exposed human primary epidermal keratinocytes (HPEKs and 3D human skin reconstructed in vitro (EpiDermTM FT-400 to UVB insult and investigated whether MBITC and MPACN treatment ameliorated the harmful effects of UVB damage. Activity was determined by the compounds’ efficacy in counteracting UVB-induced DNA damage, matrix-metalloproteinase (MMP expression, and proliferation. We found that in monolayer cultures of HPEK, MBITC and MPACN did not protect against a UVB-induced loss in proliferation and MBITC itself inhibited cell proliferation. However, in human reconstructed skin-equivalents, MBITC and MPACN decrease epidermal cyclobutane pyrimidine dimers (CPDs and significantly reduce total phosphorylated γH2A.X levels. Both MBITC and MPACN inhibit UVB-induced MMP-1 and MMP-3 expression indicating their role to prevent photoaging. Both compounds, and MPACN in particular, showed activity against UVB-induced proliferation as indicated by fewer epidermal PCNA+ cells and prevented UVB-induced hyperplasia as determined by a reduction in reconstructed skin epidermal thickness (ET. These data demonstrate that MBITC and MPACN exhibit promising anti-photocarcinogenic and anti-photoaging properties in the skin microenvironment and could be used for therapeutic interventions.

Exogenous indirect photoinactivation of bacterial pathogens and indicators in water with natural and synthetic photosensitizers in simulated sunlight with reduced UVB.

Science.gov (United States)

Maraccini, P A; Wenk, J; Boehm, A B

2016-08-01

To investigate the UVB-independent and exogenous indirect photoinactivation of eight human health-relevant bacterial species in the presence of photosensitizers. Eight bacterial species were exposed to simulated sunlight with greatly reduced UVB light intensity in the presence of three synthetic photosensitizers and two natural photosensitizers. Inactivation curves were fit with shoulder log-linear or first-order kinetic models, from which the presence of a shoulder and magnitude of inactivation rate constants were compared. Eighty-four percent reduction in the UVB light intensity roughly matched a 72-95% reduction in the overall bacterial photoinactivation rate constants in sensitizer-free water. With the UVB light mostly reduced, the exogenous indirect mechanism contribution was evident for most bacteria and photosensitizers tested, although most prominently with the Gram-positive bacteria. Results confirm the importance of UVB light in bacterial photoinactivation and, with the reduction of the UVB light intensity, that the Gram-positive bacteria are more vulnerable to the exogenous indirect mechanism than Gram-negative bacteria. UVB is the most important range of the sunlight spectrum for bacterial photoinactivation. In aquatic environments where photosensitizers are present and there is high UVB light attenuation, UVA and visible wavelengths can contribute to exogenous indirect photoinactivation. © 2016 The Society for Applied Microbiology.

UVB DNA dosimeters analyzed by polymerase chain reactors

International Nuclear Information System (INIS)

Yoshida, Hiroko; Regan, J.D.; Florida Inst. of Tech., Melbourne, FL

1997-01-01

Purified bacteriophage λ DNA was dried on a UV-transparent polymer film and served as a UVB dosimeter for personal and ecological applications. Bacteriophage λ DNA was chosen because it is commercially available and inexpensive, and its entire sequence is known. Each dosimeter contained two sets of DNA sandwiched between UV-transparent polymer films, one exposed to solar radiation (experimental) and another protected from UV radiation by black paper (control). The DNA dosimeter was then analyzed by a polymerase chain reaction (PCR) that amplifies a 500 base pair specific region of λ DNA. Photoinduced damage in DNA blocks polymerase from synthesizing a new strand; therefore, the amount of amplified product in UV-exposed DNA was reduced from that found in control DNA. The dried λ DNA dosimeter is compact, robust, safe and transportable, stable over long storage times and provides the total UVB dose integrated over the exposure time. (author)

UV-B Perceived by the UVR8 Photoreceptor Inhibits Plant Thermomorphogenesis.

Science.gov (United States)

Hayes, Scott; Sharma, Ashutosh; Fraser, Donald P; Trevisan, Martine; Cragg-Barber, C Kester; Tavridou, Eleni; Fankhauser, Christian; Jenkins, Gareth I; Franklin, Keara A

2017-01-09

Small increases in ambient temperature can elicit striking effects on plant architecture, collectively termed thermomorphogenesis [1]. In Arabidopsis thaliana, these include marked stem elongation and leaf elevation, responses that have been predicted to enhance leaf cooling [2-5]. Thermomorphogenesis requires increased auxin biosynthesis, mediated by the bHLH transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) [6-8], and enhanced stability of the auxin co-receptor TIR1, involving HEAT SHOCK PROTEIN 90 (HSP90) [9]. High-temperature-mediated hypocotyl elongation additionally involves localized changes in auxin metabolism, mediated by the indole-3-acetic acid (IAA)-amido synthetase Gretchen Hagen 3 (GH3).17 [10]. Here we show that ultraviolet-B light (UV-B) perceived by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8) [11] strongly attenuates thermomorphogenesis via multiple mechanisms inhibiting PIF4 activity. Suppression of thermomorphogenesis involves UVR8 and CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1)-mediated repression of PIF4 transcript accumulation, reducing PIF4 abundance. UV-B also stabilizes the bHLH protein LONG HYPOCOTYL IN FAR RED (HFR1), which can bind to and inhibit PIF4 function. Collectively, our results demonstrate complex crosstalk between UV-B and high-temperature signaling. As plants grown in sunlight would most likely experience concomitant elevations in UV-B and ambient temperature, elucidating how these pathways are integrated is of key importance to the understanding of plant development in natural environments. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Major inter-personal variation in the increase and maximal level of 25-hydroxy vitamin D induced by UVB

DEFF Research Database (Denmark)

Datta, Pameli; Philipsen, Peter A.; Olsen, Peter

2016-01-01

Vitamin D influences skeletal health as well as other aspects of human health. Even when the most obvious sources of variation such as solar UVB exposure, latitude, season, clothing habits, skin pigmentation and ethnicity are selected for, variation in the serum 25-hydroxy vitamin D (25(OH......)D) response to UVB remains extensive and unexplained. Our study assessed the inter-personal variation in 25(OH)D response to UVR and the maximal obtainable 25(OH)D level in 22 healthy participants (220 samples) with similar skin pigmentation during winter with negligible ambient UVB. Participants received...... identical UVB doses on identical body areas until a maximal level of 25(OH)D was reached. Major inter-personal variation in both the maximal obtainable UVB-induced 25(OH)D level (range 85–216 nmol l−1, mean 134 nmol l−1) and the total increase in 25(OH)D (range 3–139 nmol l−1, mean 48 nmol l−1) was found...

UV-B induces DNA damage and DNA synthesis delay in the marine diatom Cyclotella sp

NARCIS (Netherlands)

Buma, A.G.J.; Van Hannen, E.J.; Veldhuis, M.; Gieskes, W.W.C.

1996-01-01

The effect of UV-B on the occurrence of DNA damage and consequences for the cell cycle were studied in the marine diatom Cyclotella sp. DNA damage was quantified by immunofluorescent detection of thymine dimers in nuclear DNA of single cells using flow cytometry. A total UV-B dose (biologically

UV-B induces DNA damage and DNA synthesis delay in the marine diatom Cyclotella sp.

NARCIS (Netherlands)

Buma, A.G.J.; van Hannen, E.J; Veldhuis, M.J W; Gieskes, W.W C

The effect of UV-B on the occurrence of DNA damage and consequences for the cell cycle were studied in the marine diatom Cyclotella sp. DNA damage was quantified by immunofluorescent detection of thymine dimers in nuclear DNA of single cells using flow cytometry. A total UV-B dose (biologically

UVB induces IL-12 transcription in human keratinocytes in vivo and in vitro

International Nuclear Information System (INIS)

Enk, C.D.; Blauvet, A.; Katz, S.I.; Mahanty, S.

1996-01-01

Human epidermal cells produce a wide range of cytokines, including those characteristic of Th2-like responses such as interleukin (IL)-4 and IL-10. As well, keratinocytes have recently been shown to produce Th1-like cytokines such as IL-12. Exposure to UVB has profound effects on the skin and systemic immune system, which is in part mediated by secretion of tumor necrosis factor (TNF)-α by epidermal cells. Because IL-12 induces production of TNF-α by certain cells of the immune system, we sought to determine whether UVB is an inducer of IL-12 gene expression in epidermal cells. Human epidermal cells were exposed to UVB radiation in vivo, isolated by suction blister technique and trypsinization and transcription of the IL-12 p35 and p40 chains was examined by RT-PCR. (Author)

Effect of Thai banana (Musa AA group) in reducing accumulation of oxidation end products in UVB-irradiated mouse skin.

Science.gov (United States)

Leerach, Nontaphat; Yakaew, Swanya; Phimnuan, Preeyawass; Soimee, Wichuda; Nakyai, Wongnapa; Luangbudnark, Witoo; Viyoch, Jarupa

2017-03-01

Chronic UVB exposure causes skin disorders and cancer through DNA strand breaks and oxidation of numerous functional groups of proteins and lipids in the skin. In this study, we investigated the effects of Thai banana (Musa AA group, "Khai," and Musa ABB group, "Namwa") on the prevention of UVB-induced skin damage when fed to male ICR mice. Mice were orally fed banana (Khai or Namwa) fruit pulps at dose of 1mg/g body weight/day for 12weeks. The shaved backs of the mice were irradiated with UVB for 12weeks. The intensity dose of UVB-exposure was increased from 54mJ/cm 2 /exposure at week 1 to 126mJ/cm 2 /exposure at week 12. A significant increase in skin thickness, lipid peroxidation, protein oxidation end products, and expression of MMP-1 was observed in UVB-irradiated mouse skin. A reduction in the accumulation of oxidation end products was found in the skin of UVB-irradiated mice receiving Khai. This occurred in conjunction with a reduction in MMP-1 expression, inhibition of epidermal thickening, and induction of γ-GCS expression. The dietary intake of Khai prevented skin damage from chronic UVB exposure by increased γ-GCS expression and reduced oxidation end products included carbonyls, malondialdehyde and 4-hydroxynonenal. Copyright © 2017 Elsevier B.V. All rights reserved.

The Effect of UV-B Radiation on Bufo arenarum Embryos Survival and Superoxide Dismutase Activity

Science.gov (United States)

Herkovits, J.; D’Eramo, J. L.; Fridman, O.

2006-01-01

The exposure of Bufo arenarum embryos to 300–310 nm UV-B at a dose of 4,104 Joule/m2 resulted in 100% lethality within 24 hr while 820 Joule/m2 was the NOEC value for short-term chronic (10 days) exposure. The dose response curves show that lethal effects are proportional with the dose and achieve its highest value within 48 hr post exposure. The superoxide dismutase (SOD) activity in amphibian embryos for sublethal UV-B exposures was evaluated by means of UV-B treatments with 273 (A), 820(B), 1368(C) and 1915(D) Joule/m2 at 2 and 5 hours post irradiation. The SOD activity in units/mg protein in A, B, C and D at 2 hr after treatments were 80.72 ± 14.29, 74.5 ± 13.19, 39.5 ± 6.99 and 10.7 ± 1.89 respectively while for control embryos it was 10.88 ± 1.31. At 5 hr after treatments the SOD values were similar to those found in control embryos. The results confirm the high susceptibility of amphibian embryos to UV-B and point out that the SOD activity is enhanced by low doses of UV-B irradiation achieving significantly higher values than in control embryos at 2 hr post exposure. PMID:16823076

Changes of MMP-1 and collagen type Ialpha1 by UVA, UVB and IRA are differentially regulated by Trx-1.

Science.gov (United States)

Buechner, Nicole; Schroeder, Peter; Jakob, Sascha; Kunze, Kerstin; Maresch, Tanja; Calles, Christian; Krutmann, Jean; Haendeler, Judith

2008-07-01

Exposure of human skin to solar radiation, which includes ultraviolet (UV) radiation (UVA and UVB) visible light and infrared radiation, induces skin aging. The effects of light have been attributed to irradiation-induced reactive oxygen species (ROS) formation, but the specific signaling pathways are not well understood. Detrimental effects of solar radiation are dermal diseases and photoaging. Exposure of cultured human dermal fibroblasts to UVA, UVB or IRA increased ROS formation in vitro. One important redox regulator is the oxidoreductase thioredoxin-1 (Trx). Trx is ubiquitously expressed and has anti-oxidative and anti-apoptotic properties. Besides its function to reduce H(2)O(2), Trx binds to and regulates transcription factors. The aim of this study was to investigate whether Trx influences the regulation of MMP-1 and collagen Ialpha1 by UVA, UVB and IRA. We irradiated human dermal fibroblasts with UVA, UVB and IRA. UVA, UVB and IRA upregulated MMP-1 expression. Trx inhibited UVA-induced MMP-1 upregulation in a NFkappaB dependent manner. UVA, UVB and IRA reduced collagen Ialpha1 expression. Incubation with Trx inhibited the effects of UVB and IRA on collagen Ialpha1 expression. In conclusion, MMP-1 and collagen Ialpha1, which play important roles in aging processes, seems to be regulated by different transcriptional mechanisms and Trx can only influence distinct signaling pathways induced by UVA, UVB and probably IRA. Thus, Trx may serve as an important contributor to an "anti-aging therapeutic cocktail".

Interactive effects of UV-B irradiation and triadimefon on nodulation and nitrogen metabolism in Vigna radiata plants

International Nuclear Information System (INIS)

Rajendiran, K.; Ramanujam, M.P.

2006-01-01

Supply of aqueous solution of triadimefon (20 mg/cubic dm) to unstressed green gram plants increased the contents of soluble proteins, amino acids, nitrate and nitrite, and the activity of nitrate reductase in the leaves and nitrate reductase in nodules. The nitrogenase activity in nodules and roots was also increased. Number and fresh mass of nodules and their nitrate and nitrite contents were also higher than those of the controls. In contrast, the UV-B stress (12.2 kJ/square m/d) suppressed nodulation and nitrogen metabolism in leaves and roots in comparison with plants under natural UV-B (10 kJ/square m/d). Triadimefon-treated plants did not show such severe inhibitions after exposure to elevated UV-B. Thus, triadimefon increased their tolerance to UV-B stress

Binding of antibodies to dsDNA by UVB-irradiated spermatozoa in vitro

Energy Technology Data Exchange (ETDEWEB)

Wollina, U; Schaarschmidt, H; Thiel, W; Knopf, B

1986-08-01

Human spermatozoa were exposed to monochromatic UVB light (300 nm) at a dosage range from 1-10/sup 3/ J/m/sup 2/ (xenon-mercury short-arc lamp) and 10/sup -2/-10/sup -1/ J/m/sup 2/ (xenon lamp). UVB irradiation >= 10 J/m/sup 2/ resulted in a subsequent binding of antibodies to double-stranded (ds) DNA. A strong homogeneous head fluorescence was visible. There was no immunoglobulin class restriction. The results were discussed in regards to lupus antigen expression by UV light.

ROS and calcium signaling mediated pathways involved in stress responses of the marine microalgae Dunaliella salina to enhanced UV-B radiation.

Science.gov (United States)

Zhang, Xinxin; Tang, Xuexi; Wang, Ming; Zhang, Wei; Zhou, Bin; Wang, You

2017-08-01

UV-B ray has been addressed to trigger common metabolic responses on marine microalgae, however, the upstream events responsible for these changes in marine microalgae are poorly understood. In the present study, a species of marine green microalgae Dunaliella salina was exposed to a series of enhanced UV-B radiation ranging from 0.25 to 1.00 KJ·m -2 per day. The role of ROS and calcium signaling in the D. salina responses to UV-B was discussed. Results showed that enhanced UV-B radiation markedly decreased the cell density in a dose-dependent manner, but the contents of protein and glycerol that were essential for cell growth increased. It suggested that it was cell division instead of cell growth that UV-B exerted negative effects on. The subcellular damages on nuclei and plasmalemma further evidenced the hypothesis. The nutrient absorption was affected with UV-B exposure, and the inhibition on PO 4 3- uptake was more serious compared to NO 3 - uptake. UV-B radiation promoted reactive oxygen species (ROS) formation and thiobarbituric acid reactive substances (TBARS) contents, decreased the redox status and altered the antioxidant enzyme activities. The addition of the ROS scavenger and the glutathione biosynthesis precursor N-acetyl-l-cysteine (NAC) alleviated the stress degree, implying ROS-mediated pathway was involved in the stress response to UV-B radiation. Transient increase in Ca 2+ -ATPase was triggered simultaneously with UV-B exposure. Meanwhile, the addition of an intracellular free calcium chelator aggravated the damage of cell division, but exogenous calcium and ion channel blocker applications did not, inferring that endogenously initiated calcium signaling played roles in response to UV-B. Cross-talk analysis showed a relatively clear relationship between ROS inhibition and Ca 2+ -ATPase suppression, and a relation between Ca 2+ inhibition and GPx activity change was also observed. It was thus presumed that ROS-coupled calcium signaling via the

Enhanced UV-B radiation has little effect on growth, delta13C values and pigments of pot-grown rice (Oryza sativa) in the field

International Nuclear Information System (INIS)

Kim, H.Y.; Kobayashi, K.; Nouchi, I.; Yoneyama, T.

1996-01-01

Predicted increase in ultraviolet-B (UV-B: 280–320 mn) radiation may have adverse impacts on growth and yield of rice (Oryza sativa L.), as has been found in studies hitherto. However, most of the studies were conducted in growth chambers or greenhouses where the plants are generally more sensitive to UV-B than in the field, presumably because of the distorted balance between UV-B and ultraviolet-A as well as PAR. This study was conducted to address the effects of enhanced UV-B on growth and yield of rice under a realistic spectral balance in the field. Three cultivars, “Koshihikari”,‘IR 45’and‘IR 74’were pot-grown and irradiated with enhanced UV-B for most of the growing season in the field at Tsukuba, Japan (36°01′N, 140°07′E). The UV-B enhancement simulated ca 38% depletion of stratospheric ozone at Tsukuba. The results showed no UV-B effects on plant height, numbers of tillers and panicles, dry weight of the plant parts or the grain yield for any of the 3 cultivars. Natural abundance of 13 C in the flag leaves was not altered by the UV-B enhancement either. While UV-absorbing compounds showed no response to the UV-B enhancement, chlorophyll contents decreased with enhanced UV-B. However, the decrease of chlorophyll was limited to an early growth stage with no effect later. We thus found no extraordinary impact of the nearly doubled UV-B radiation on rice in the field, and it would appear that a reliable prediction of the effects of UV-B will require experiments carried out over a number of years under various climatic and solar UV-B regimes. (author)

Alteration of foliar flavonoid chemistry induced by enhanced UV-B radiation in field-grown Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii.

Science.gov (United States)

Warren, Jeffrey M; Bassman, John H; Mattinson, D Scott; Fellman, John K; Edwards, Gerald E; Robberecht, Ronald

2002-03-01

Chromatographic analyses of foliage from several tree species illustrate the species-specific effects of UV-B radiation on both quantity and composition of foliar flavonoids. Pinus ponderosa, Quercus rubra and Pseudotsuga menziesii were field-grown under modulated ambient (1x) and enhanced (2x) biologically effective UV-B radiation. Foliage was harvested seasonally over a 3-year period, extracted, purified and the flavonoid fraction applied to a mu Bondapak/C(18) column HPLC system sampling at 254 nm. Total flavonoid concentrations in Quercus rubra foliage were more than twice (leaf area basis) that of the other species; Pseudotsuga menziesii foliage had intermediate levels and P. ponderosa had the lowest concentrations of total flavonoids. No statistically significant UV-B radiation-induced effects were found in total foliar flavonoid concentrations for any species; however, concentrations of specific compounds within each species exhibited significant treatment effects. Higher (but statistically insignificant) levels of flavonoids were induced by UV-B irradiation in 1- and 2-year-old P. ponderosa foliage. Total flavonoid concentrations in 2-year-old needles increased by 50% (1x ambient UV-B radiation) or 70% (2x ambient UV-B radiation) from that of 1-year-old tissue. Foliar flavonoids of Q. rubra under enhanced UV-B radiation tended to shift from early-eluting compounds to less polar flavonoids eluting later. There were no clear patterns of UV-B radiation effects on 1-year-old P. menziesii foliage. However, 2-year-old tissue had slightly higher foliar flavonoids under the 2x UV-B radiation treatment compared to ambient levels. Results suggest that enhanced UV-B radiation will alter foliar flavonoid composition and concentrations in forest tree species, which could impact tissue protection, and ultimately, competition, herbivory or litter decomposition.

Cooling Down Thermomorphogenesis by UV-B Signaling.

Science.gov (United States)

Yin, Ruohe

2017-06-01

PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) is a key transcriptional regulator promoting plant responses to elevated ambient temperatures. A recent study reported that the ultraviolet B radiation (UV-B) photoreceptor UVR8 signaling pathway inhibits PIF4 via multiple mechanisms to repress plant responses to high ambient temperatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

A study of the photodegradation of leukotriene B4 by ultraviolet irradiation (UVB, UVA)

International Nuclear Information System (INIS)

Millar, B.; Green, C.; Ferguson, J.; Raffle, E.J.; Macleod, T.M.

1989-01-01

In view of the presence of the polymorphonuclear leukocyte (PMN) chemoattractant Leukotriene B 4 (LTB 4 ) in surface scale of the psoriatic lesion and the known therapeutic effect of phototherapy in psoriasis, the photostability of LTB 4 was investigated. LTB 4 was irradiated with UVB (290-320 nm) from 100-1500 mJ cm -2 and UVA (320-400 nm) from 5-40 J cm -2 . Topical application of UVB irradiated LTB 4 to forearm skin of normal volunteers showed marked reduction in cutaneous erythema, paralleled by reduced transepidermal PMN migration compared with sites of application of unirradiated and UVA irradiated LTB 4 . High performance liquid chromatography (HPLC) demonstrated a dose-dependent photodegradation of LTB 4 by UVB irradiation. UVA irradiation produced no such effect. The wavelengths responsible lie within the absorption spectrum of LTB 4 . In vitro chemotaxis studies, using an under agarose technique, showed a statistically significant reduction in the migration of PMN from psoriatic and non-psoriatic subjects to the UVB irradiated LTB 4 compared with unirradiated LTB 4 , whilst UVA irradiated LTB 4 produced a normal PMN chemotactic response. (author)

Molecular Insights into SIRT1 Protection Against UVB-Induced Skin Fibroblast Senescence by Suppression of Oxidative Stress and p53 Acetylation.

Science.gov (United States)

Chung, Ki Wung; Choi, Yeon Ja; Park, Min Hi; Jang, Eun Ji; Kim, Dae Hyun; Park, Byung Hyun; Yu, Byung Pal; Chung, Hae Young

2015-08-01

Stresses, such as exposure to ultraviolet radiation and those associated with aging, are known to cause premature cellular senescence that is characterized by growth arrest and morphological and gene expression changes. This study was designed to investigate the protective effect of Sirtuin1 (SIRT1) on the UVB-induced premature senescence. Under in vitro experimental conditions, exposure to a subcytotoxic dose of UVB enhanced human skin fibroblasts senescence, as characterized by increased β-galactosidase activity and increased levels of senescence-associated proteins. However, adenovirus-mediated SIRT1 overexpression significantly protected fibroblasts from UVB-induced cellular deterioration. Exposure to UVB-induced cell senescence was associated with oxidative stress and p38 mitogen-activated protein kinase activation. Molecular analysis demonstrated that deacetylation of Forkhead box O3α (FOXO3α) by SIRT1 changed the transcriptional activity of FOXO3α and increased resistance to the oxidative stress. In addition, SIRT1 suppressed UVB-induced p53 acetylation and its transcriptional activity, which directly affected the cell cycle arrest induced by UVB. Further study demonstrated that SIRT1 activation inhibited cell senescence in the skin of the HR1 hairless mouse exposed to UVB. The study identifies a new role for SIRT1 in the UVB-induced senescence of skin fibroblats and provides a potential target for skin protection through molecuar insights into the mechanisms responsible for UVB-induced photoaging. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A flavonoid mutant of barley (Hordeum vulgare L.) exhibits increased sensitivity to UV-B radiation in the primary leaf

International Nuclear Information System (INIS)

Reuber, S.; Bornman, J.F.; Weissenböck, G.

1996-01-01

The aim of the present investigation was to define the role of soluble flavonoids as UV-B protectants in the primary leaf of barley (Hordeum vulgare L.). For this purpose we used a mutant line (Ant 287) from the Carlsberg collection of proanthocyanidin-free barley containing only 7% of total extractable flavonoids in the primary leaf as compared to the mother variety (Hiege 550/75). Seven-day-old leaves from plants grown under high visible light with or without supplementary UV-B radiation were used for the determination of UV-B sensitivity. UV-B-induced changes were assessed from parameters of chlorophyll fluorescence of photosystem II, including initial and maximum fluorescence, apparent quantum yield, and photochemical and non-photochemical quenching. A quartz fibre-optic microprobe was used to evaluate the amount of potentially harmful UV-B (310 nm radiation) penetrating into the leaf as a direct consequence of flavonoid deficiency. Our data indicate an essential role of flavonoids in UV-B protection of barley primary leaves. In leaves of the mutant line grown under supplementary UV-B, an increase in 310nm radiation in the mesophyll and a strong decrease in the quantum yield of photosynthesis were observed as compared to the corresponding mother variety. Primary leaves of liege responded to supplementary UV-B radiation with a 30% increase in the major flavonoid saponarin and a 500% increase in the minor compound lutonarin. This is assumed to be an efficient protective response since no changes in variable chlorophyll fluorescence were apparent. In addition, a further reduction in UV-B penetration into the mesophyll was recorded in these leaves

[Effects of silicon supply on rice growth and methane emission from paddy soil under elevated UV-B radiation].

Science.gov (United States)

Meng, Yan; Lou, Yun-sheng; Wu, Lei; Cui, He-yang; Wang, Wei-qing

2015-01-01

A pot experiment was conducted to investigate the effects of silicon supply on rice growth and methane (CH4) emission in paddy field under elevated UV-B radiation. The experiment was designed with two UV-B radiation levels, i.e. ambient UV-B (ambient, A) and elevated UV-B radiation (elevated by 20%, E) ; with four silicon supply levels, i.e., Si0 (control, without silicon), Si2 (as sodium silicate, 100 kg SiO2 . hm-2), Si2 (as sodium silicate, 200 kg SiO2 hm-2) and Si3 (as slag fertilizer, 200 kg SiO2 . hm-2). The results indicated that, silicon supply obviously alleviated the depressive effect of elevated UV-B radiation on rice growth, and increased the tiller numbers, chlorophyll content, and shoot and root dry masses. Silicon supply promoted rice growth, which increased with the silicon supply level (sodium silicate). Slag fertilizer was better than*sodium silicate in promoting rice growth. CH4 flux and accumulated CH4emission were obviously increased by elevated UV-B radiation, but significantly decreased by silicon application. CH4 emission was reduced with increasing the silicon supply level. Under the same silicon supply level, slag fertilizer was better than sodium silicate in inhibiting CH4 flux and accumulated CH4 emission. This research suggested that fertilizing slag in rice production was helpful not only in utilizing industrial wastes, but also in significantly mitigating CH4 emissions in rice paddy under elevated UV-B radiation.

Effects of UV-B radiation on soybean yield and seed quality: a 6-year field study

International Nuclear Information System (INIS)

Teramura, A.H.; Sullivan, J.H.; Lydon, J.

1990-01-01

Two soybean [Glycine max (L.) Merr.] cultivars, Essex and Williams, were grown in the field for 6 consecutive seasons under ambient and supplemental levels of ultravio-Set-B radiation to determine the potential for alterations in yield or seed quality with a reduction in the stratospheric ozone column. The supplemental UV-B fluences simulated a 16 or 25% ozone depletion. The data presented here represent the first field experiment conducted over multiple seasons which assesses the effects of increased UV-B radiation on seed yield. Overall, the cultivar Essex was found to be sensitive to UV-B radiation (yield reductions of 20%) while the cultivar Williams was tolerant. However, the effectiveness of UV-B radiation in altering yield was strongly influenced by the seasonal microclimate, and the 2 cultivars responded differently to these changing factors. Yield was reduced most in Essex during seasons in which water availability was high and was reduced in Williams only when water was severely limiting. The results of these experiments demonstrate the necessity for multiple-year experiments and the need to increase our understanding of the interaction between UV-B radiation and other environmental stresses in order to assess the potential consequences of stratospheric ozone depletion. (author)

UVB-induced decreased resistance to Trichinella spiralis in the rat is related to impaired cellular immunity

International Nuclear Information System (INIS)

Goettsch, W.; Garssen, J.; Loveren, H. van; Gruijl, F.R. de

1996-01-01

Our laboratory has demonstrated in preliminary experiments that UVB exposure using the Kromayer lamp can induce increased numbers of Trichinella spiralis larvae in carcasses of infected Wistar rats, without affecting specific antibody titers to this parasite. In this study, orally T.spiralis-infected Wistar rats were exposed to subery-thermal doses of UVB radiation using FS40 lamps during different time periods before or after infection. A significant increase in the number of T. spiralis larvae was found in the carcasses of rats that were UVB irradiated daily for 7 consecutive days in the second week after infection. Additionally, increased numbers of larvae were also detected histologically in the tongue of rats that were exposed the first and the second week after infection. Lymphocyte stimulation assays using mesenteral lymph node cells indicated that UVB exposure also impaired the specific lymphocyte response to T. spiralis. Moreover, DTH responses to T. spiralis were severely impaired in rats that were UVB irradiated daily for 7 consecutive days in the second week after infection. Thus, these data combined with the data of the Kromayer study indicate that exposure of rats to FS40 irradiation following oral infection with T. spiralis leads to increased numbers of larvae in systemic sites and impaired T-cell immunity to the parasite. (Author)

UV-B affects photosynthesis, ROS production and motility of the freshwater flagellate, Euglena agilis Carter

Energy Technology Data Exchange (ETDEWEB)

Kottuparambil, Sreejith [Institute of Green Environmental Research Center, University of Incheon, Incheon, 406 840 (Korea, Republic of); Shin, Woongghi [Department of Biology, Chungnam University, Daejeon, 306 764 (Korea, Republic of); Brown, Murray T. [School of Marine Science and Engineering, Plymouth University, Drake Circus, Plymouth PL4 8AA (United Kingdom); Han, Taejun, E-mail: hanalgae@hanmail.net [Institute of Green Environmental Research Center, University of Incheon, Incheon, 406 840 (Korea, Republic of); Department of Marine Science, University of Incheon, Incheon, 406 840 (Korea, Republic of)

2012-10-15

Highlights: Black-Right-Pointing-Pointer We proposed a hypothesis for the UV-B protective/adaptive mechanism in Euglena agilis. After moderate levels of UV-B radiation, ROS plays a signaling role to shut down photosynthetic system for protection against harmful UV radiation. Black-Right-Pointing-Pointer E. agilis exposed to excessive UV appears to become animal-like, investing all its stored energy into movement rather than into sustaining its photosynthetic machinery. Black-Right-Pointing-Pointer This adaptation allows E. agilis to avoid harmful UV and seek a safe place where the organism may regain its photosynthetic capacity for survival. - Abstract: The effects of ultraviolet B (UV-B; 295-320 nm) radiation on certain vital physiological (photosynthesis), biochemical (production of reactive oxygen species - ROS) and behavioral (motility and orientation) characteristics were investigated in the unicellular photoautotroph, Euglena agilis Carter. The photosynthetic performance of E. agilis was recorded after exposure of between 15 and 60 min followed by a period of recovery lasting 6-24 h under dim light (5-10 {mu}mol photons m{sup -2} s{sup -1}). The maximum quantum yield of PS II (F{sub v}/F{sub m}) was reduced to 65% and 14% of initial values immediately following 15 and 30 min UV-B exposure, but recovered to 100 and 86% of the initials, respectively. Values of rETR{sub max} in E. agilis exposed to 15 min UV-B were similar to those of the initials, but a 30 min UV exposure resulted in 75% reduction of rETR{sub max} with only a 43% recovery as compared with the initial after 24 h recovery. After a 60 min UV-B exposure, there were no Chl a fluorescence signals, and hence no F{sub v}/F{sub m} or rETR{sub max}. A UV dose-dependent increase in DCFH-DA fluorescence was found in E. agilis cells, reflecting an increase in ROS production. After exposures to UV-B for between 15 and 60 min, the percentages of motile cells in the population decreased to 76, 39 and 15

UVB exposure of farm animals: study on a food-based strategy to bridge the gap between current vitamin D intakes and dietary targets.

Directory of Open Access Journals (Sweden)

Alexandra Schutkowski

Full Text Available Vitamin D deficiency is a global health problem. This study aimed to investigate the efficacy of ultraviolet (UV B radiation for improving vitamin D3 content of eggs and meat. In a two-factorial design hens that received diets with 0 (-D3 or 3,000 IU (+D3 vitamin D3/kg were non-exposed (-UVB or exposed to UVB radiation (+UVB for 3 h daily over 4 weeks. Data show that UVB radiation was very effective in raising the vitamin D3 content of egg yolk and meat. Egg yolk from +UVB/-D3 hens had a higher vitamin D3 content (17.5±7.2 µg/100 g dry matter (DM than those from the -UVB/+D3 group (5.2±2.4 µg/100 g DM, p<0.01. Vitamin D3 content in egg yolk of vitamin D3-supplemented hens could be further increased by UVB radiation (32.4±10.9 µg/100 g DM. The content of 25-hydroxyvitamin D3 (25(OHD3 in the egg yolk also increased in response to UVB, although less pronounced than vitamin D3. Meat revealed about 4-fold higher vitamin D3 contents in response to UVB than to dietary vitamin D3 (p<0.001. In conclusion, exposure of hens to UVB is an efficient approach to provide consumers with vitamin D3-enriched foods from animal sources.

Influence of low ozone episodes on erythemal UV-B radiation in Austria

Science.gov (United States)

Schwarz, Matthias; Baumgartner, Dietmar J.; Pietsch, Helga; Blumthaler, Mario; Weihs, Philipp; Rieder, Harald E.

2017-06-01

This study investigates the influence of low ozone episodes on UV-B radiation in Austria during the period 1999 to 2015. To this aim observations of total column ozone (TCO) in the Greater Alpine Region (Arosa, Switzerland; Hohenpeissenberg, Germany; Hradec Kralove, Czech Republic; Sonnblick, Austria), and erythemal UV-B radiation, available from 12 sites of the Austrian UV-B monitoring network, are analyzed. As previous definitions for low ozone episodes are not particularly suited to investigate effects on UV radiation, a novel threshold approach—considering anomalies—is developed to provide a joint framework for the analysis of extremes. TCO and UV extremes are negatively correlated, although modulating effects of sunshine duration impact the robustness of the statistical relationship. Therefore, information on relative sunshine duration (SDrel), available at (or nearby) UV-B monitoring sites, is included as explanatory variable in the analysis. The joint analysis of anomalies of both UV index (UVI) and total ozone (∆UVI, ∆TCO) and SDrel across sites shows that more than 65% of observations with strongly negative ozone anomalies (∆TCO 1), we find (across all sites) that about 90% correspond to negative ∆TCO. The remaining 10% of days occurred during fair weather conditions (SDrel ≥ 80%) explaining the appearance of ∆UVI > 1 despite positive TCO anomalies. Further, we introduce an anomaly amplification factor (AAF), which quantifies the expected change of the ∆UVI for a given change in ∆TCO.

Narrowband UVB emitting (LaGd)B3O6:Bi3+ phosphor for phototherapy

International Nuclear Information System (INIS)

Bhatkar, N.V.; Thakare, D.S.; Bhatkar, V.B.

2011-01-01

Ultraviolet radiation (UVR) phototherapy is useful for treating more than 40 types of skin diseases and disorders, such as psoriasis, vitiligo, atopic dermatitis, morphea, scleroderma, cutaneous T-cell lymphoma, etc. Action spectrum studies have shown that the peak therapeutic activity is between 295 - 310 nm. A recent advance in phototherapy of psoriasis has been the introduction of narrowband UVB using a fluorescence irradiation device delivering virtually monochromatic light at 311 nm. Combining narrowband UVB with calcipotriol, a vitamin D 3 analogue, is considered a very effective treatment for psoriasis. Narrowband UVB is a useful therapy for the treatment of Vitiligo. Research into the influence of wavelength on therapeutic efficacy in phototherapy, confirmed that narrowband UVB is more effective and probably has no greater risk than conventional wideband UVB phototherapy in the treatment of skin disease. In addition, it was recognized that this would be an opportunity for better control and evaluation of treatment, faster and easier treatment time and potentially improved clearance. Lanthanum metaborate (LaGd)B 3 O 6 :Bi 3+ is a well- known commercial narrowband emitting phosphor used in phototherapy lamps for the treatment of psoriasis. The phosphor was prepared by a novel method which is a variation of the solution combustion synthesis. Heat generated in the exothermic reaction between ammonium nitrate and urea is used to carry out the synthesis. The XRD pattern of the prepared phosphor matches with the standard ICDD data. The PL emission of the prepared phosphor shows a narrowband emission spectrum centered around 310 nm in good agreement with the literature. (author)

Comparison of UVB and UVC irradiation disinfection efficacies on Pseudomonas Aeruginosa (P. aeruginosa) biofilm

Science.gov (United States)

Argyraki, A.; Markvart, M.; Nielsen, Anne; Bjarnsholt, T.; Bjørndal, L.; Petersen, P. M.

2016-04-01

Disinfection routines are important in all clinical applications. The uprising problem of antibiotic resistance has driven major research efforts towards alternative disinfection approaches, involving light-based solutions. Pseudomonas aeruginosa (P. aeruginosa) is a common bacterium that can cause skin, soft tissue, lungs, kidney and urinary tract infections. Moreover, it can be found on and in medical equipment causing often cross infections in hospitals. The objective of this study was to test the efficiency, of two different light-based disinfection treatments, namely UVB and UVC irradiation, on P. aeruginosa biofilms at different growth stages. In our experiments a new type of UV light emitting diodes (LEDs) were used to deliver UV irradiation on the biofilms, in the UVB (296nm) and UVC (266nm) region. The killing rate was studied as a function of dose for 24h grown biofilms. The dose was ramped from 72J/m2 to 10000J/m2. It was shown that UVB irradiation was more effective than UVC irradiation in inactivating P. aeruginosa biofilms. No colony forming units (CFU) were observed for the UVB treated biofilms when the dose was 10000 J/m2 (CFU in control sample: 7.5 x 104). UVB irradiation at a dose of 20000J/m2 on mature biofilms (72h grown) resulted in a 3.9 log killing efficacy. The fact that the wavelength of 296nm exists in daylight and has such disinfection ability on biofilms gives new perspectives for applications within disinfection at hospitals.

Enhanced UV-B radiation alleviates the adverse effects of summer drought in two Mediterranean pines under field conditions [ozone depletion

International Nuclear Information System (INIS)

Petropoulou, Y.; Kyparissis, A.; Nikolopoulos, D.; Manetas, Y.

1995-01-01

The effects of enhanced UV-B (290-320 nm) radiation on two native Mediterranean pines (Pinus pinea L., Pinus halepensis Mill.) were recorded during a one-year field study. Plants received ambient or ambient plus supplemental UV-B radiation (simulating a 15% stratospheric ozone depletion over Patras. Greece, 38.3°N. 29.1°E) and only natural precipitation, i.e. they were simultaneously exposed to other natural stresses. particularly water stress during summer. Supplemental UV-B irradiation started in early February, 1993 and up to late June, no effects were observed on growth and photochemical efficiency of photosystem II, as measured by chlorophy II fluorescence induction. Water stress during the summer was manifested in the control plants as a decline in the ratio of variable to maximum fluorescence (F v /F m ), the apparent photon yield for oxygen evolution (φ I ) and the photosynthetic capacity at 5% CO 2 (P m ). In addition, a partial needle loss was evident. Under supplemental UV-B radiation, however, the decreases in F v /F m , φ i , and P m . as well as needle losses were significantly less. Soon after the first heavy autumn rains. photosynthetic parameters in both control and UV-B treated plants recovered to similar values. but the transient summer superiority of UV-B irradiated plants resulted in a significant increase in their dry weight measured at plant harvest. during late January. 1994. Plant height. UV-B absorbing compounds, photosynthetic pigments and relative water content measured at late spring. late summer and at plant harvest, were not significantly affected by supplemental UV-B radiation. The results indicate that enhanced UV-B radiation may be beneficial for Mediterranean pines through a partial alleviation of the adverse effects of summer drought. (author)

Effect of UVB irradiation of the blood on cellular volume adherence and phagocytosis in probands and patients with multiple sclerosis

Energy Technology Data Exchange (ETDEWEB)

Mix, E; Jenssen, H L; Lehmitz, R; Buddenhagen, F; Hitzschke, B; Richter, M

1988-01-01

UVB-induced changes of blood cell properties were investigated in 12 multiple sclerosis (MS) patients and in 10 healthy volunteers. The mean cell volume (MCV) was determined by electronic sizing, the granulocyte and lymphocyte adherence was estimated in a capillary assay, and the phagocytic activity of granulocytes was measured in a test system based on the incorporation of opsonized baker's yeast. In MS patients the MCV of red cells and lymphocytes decreased rapidly within 6 UVB treatments. In contrast, the reduction of the granulocyte volume was delayed (between the 6th and 12th UVB). In the control group the mean value of the red cell and lymphocyte MCV remained rather unaffected. There was a slight rise of the granulocyte volume after the 6th UVB. The only significant change of adherence was an increase of granulocyte adherence in MS patients. Untreated patients had a significantly enhanced phagocytic activity in comparison to the control group. 6 UVB treatments induced a singificant reduction of the phagocytic activity in MS patients. However, subsequently the percentage of phagocytizing cells increased again, whereas the particle uptake per cell continued to decrease. In the control group only minor UVB-induced changes of phagocytosis were observed. The in vitro UV irradiation caused an enhanced phagocytosis in the majority of cases in both controls and MS patients. In general, under the UVB treatment all parameters examined changed in the sense of a normalisation, in that the measured values reached a new level lying between the extreme pretreatment values accompanied by a reduced standard deviation. The effect of UVB was more pronounced in MS patients when compared with normal control. This could result from an enhanced sensitivity to the influence of UVB of pathologically altered cells in MS patients. (Abstract Truncated)

The imprints of the high light and UV-B stresses in Oryza sativa L. 'Kanchana' seedlings are differentially modulated.

Science.gov (United States)

Faseela, Parammal; Puthur, Jos T

2018-01-01

High light and ultraviolet-B radiation (UV-B) are generally considered to have negative impact on photosynthesis and plant growth. The present study evaluates the tolerance potential of three cultivars of Oryza sativa L. (Kanchana, Mattatriveni and Harsha) seedlings towards high light and UV-B stress on the basis of photosynthetic pigment degradation, chlorophyll a fluorescence parameters and rate of lipid peroxidation, expressed by malondialdehyde content. Surprisingly, it was revealed that Kanchana was the most sensitive cultivar towards high light and at the same time it was the most tolerant cultivar towards UV-B stress. This contrasting feature of Kanchana towards high light and UV-B tolerance was further studied by analyzing photosystem (PS) I and II activity, mitochondrial activity, chlorophyll a fluorescence transient, enzymatic and non-enzymatic antioxidant defense system. Due to the occurrence of more PS I and PSII damages, the inhibition of photochemical efficiency and emission of dissipated energy as heat or fluorescence per PSII reaction center was higher upon high light exposure than UV-B treatments in rice seedlings of Kanchana. The mitochondrial activity was also found to be drastically altered upon high light as compared to UV-B treatments. The UV-B induced accumulation of non-enzymatic antioxidants (proline, total phenolics, sugar and ascorbate) and enzymatic antioxidants (ascorbate peroxidase, guaiacol peroxidase, superoxide dismutase and glutathione reductase) in rice seedlings than those subjected to high light exposure afforded more efficient protection against UV-B radiation in rice seedlings. Our results proved that high tolerance of Kanchana towards UV-B than high light treatments, correlated linearly with the protected photosynthetic and mitochondrial machinery which was provided by upregulation of antioxidants particularly by total phenolics, ascorbate and ascorbate peroxidase in rice seedlings. Data presented in this study conclusively

Short-term UV-B radiation and ozone exposure effects on aromatic secondary metabolite accumulation and shoot growth of flavonoid-deficient Arabidopsis mutants

International Nuclear Information System (INIS)

Ormrod, D.P.; Landry, L.G.; Conklin, P.L.

1995-01-01

The presence of UV-absorptive substances in the epidermal cells of leaves is thought to protect mesophyll tissues from the harmful effects of UV-B radiation. We examined the influence of short-term UV-B exposures on UV-absorptive (330 nm) sinapates and flavonols, and on shoot growth of the Arabidopsis wild type ecotype Landsberg erecta and two mutants. 114 deficient in chalcone synthase, and 115, deficient in chalcone/flavonone isomerase. Sequential ozone exposures were used to determine the effects of oxidative stress The levels of sinapates and flavonols on a leaf fresh weight basis increased substantially in the wild type and sinapates increased in the 114 mutant in vegetative vegetative/reproductive transitional and reproductive stage plants in response to short-term (48h) UV-B radiation. When UV-B was discontinued the levels generally decreased lo pre-exposure levels after 48 h in vegetative/reproductive but not in reproductive plants. Exposure to ozone before or alter UV-B treatment did not consistently affect the levels of these UV-absorptive compounds. Dry matter accumulation was less affected by UV-B at the vegetative and reproductive stages than at the vegetative/reproductive stage. At the vegetative/reproductive stage, shoot growth of all 3 genotypes was retarded by UV-B. Growth was not retarded by short-term ozone exposure alone but when exposure to ozone followed UV-B exposure, growth was reduced in all genotypes. Leaf cupping appeared on 115 plants exposed to UV-B

Depletion of stratospheric ozone over the Antarctic and Arctic: Responses of plants of polar terrestrial ecosystems to enhanced UV-B, an overview

International Nuclear Information System (INIS)

Rozema, Jelte; Boelen, Peter; Blokker, Peter

2005-01-01

Depletion of stratospheric ozone over the Antarctic has been re-occurring yearly since 1974, leading to enhanced UV-B radiation. Arctic ozone depletion has been observed since 1990. Ozone recovery has been predicted by 2050, but no signs of recovery occur. Here we review responses of polar plants to experimentally varied UV-B through supplementation or exclusion. In supplementation studies comparing ambient and above ambient UV-B, no effect on growth occurred. UV-B-induced DNA damage, as measured in polar bryophytes, is repaired overnight by photoreactivation. With UV exclusion, growth at near ambient may be less than at below ambient UV-B levels, which relates to the UV response curve of polar plants. UV-B screening foils also alter PAR, humidity, and temperature and interactions of UV with environmental factors may occur. Plant phenolics induced by solar UV-B, as in pollen, spores and lignin, may serve as a climate proxy for past UV. Since the Antarctic and Arctic terrestrial ecosystems differ essentially (e.g. higher species diversity and more trophic interactions in the Arctic), generalization of polar plant responses to UV-B needs caution. - Polar plant responses to UV-B may be different in the Arctic than Antarctic regions

Differences in the photosynthetic UV-B response between European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) saplings

International Nuclear Information System (INIS)

Šprtová, M.; Marek, M.V.; Urban, O.; Kalina, J.; Špunda, V.

2008-01-01

Cloned saplings of Norway spruce (Picea abies (L) Karst.) and beech (Fagus sylvatica L.) (7 years old) were exposed to enhanced UV-B irradiation (+25%) continuously over three growing seasons (1999-2001). Selected parameters of variable chlorophyll alpha fluorescence and pigment composition were analysed in the late summer of the third growing season to evaluate the influence of long-term elevated UV-B irradiation on broadleaf and conifer tree species. To obtain information on the xanthophyll cycle, the de-epoxidation state (DEPS) was calculated. These tree species responded differentially to the long-term effects of enhanced UV-B radiation, Norway spruce was more sensitive compared to the European beech. The results show that in Norway spruce long-term exposure to enhanced UV-B radiation under field conditions caused negative changes at the level of primary photosynthetic reactions. Contrary to the beech, this had higher degree of UV-B protective responses. UV-B radiation is not effective stressor to its primary photosynthetic reaction

The effect of UV-B radiation on photosynthesis and respiration of phytoplankton, benthic macroalgae and seagrasses.

Science.gov (United States)

Larkum, A W; Wood, W F

1993-04-01

Several species of marine benthic algae, four species of phytoplankton and two species of seagrass have been subjected to ultraviolet B irradiation for varying lengths of time and the effects on respiration, photosynthesis and fluorescence rise kinetics studied. No effect on respiration was found. Photosynthesis was inhibited to a variable degree in all groups of plants after irradiation over periods of up to 1 h and variable fluorescence was also inhibited in a similar way. The most sensitive plants were phytoplankton and deep-water benthic algae. Intertidal benthic algae were the least sensitive to UV-B irradiation and this may be related to adaptation, through the accumulation of UV-B screening compounds, to high light/high UV-B levels. Inhibition of variable fluorescence (Fv) of the fluorescence rise curve was a fast and sensitive indicator of UV-B damage. Two plants studied, a brown alga and a seagrass, showed very poor recovery of Fv over a period of 32 h.

Endogenous glutathione protects human skin fibroblasts against the cytotoxic action of UVB, UVA and near-visible radiations

International Nuclear Information System (INIS)

Tyrell, R.M.; Pidoux, Mireille

1986-01-01

Both the UVB (290-320 nm) and UVA (320-380 nm) regions of sunlight damage human skin cells but, particularly at the longer wavelengths, information is scant concerning the mechanism(s) of damage induction and the roles of cellular defense mechanisms. Following extensive glutathione depletion of cultured human skin fibroblasts, the cells become strongly sensitized to the cytotoxic action of near-visible (405 nm), UVA (334 nm, 365 nm) and UVB (313 nm) but not UVC (254 nm) radiations. In the critical UVB region, the magnitude of the protection afforded by endogenous glutathione approaches that of the protection provided by excision repair. The results suggest that a significant fraction of even UVB damage can be mediated by free radical attack and that a major role of glutathione in human skin cells is to protect them from the cytotoxic action of sunlight. (author)

The sensitivity of sunflower (Helianthus annuus L.) plants to UV-B radiation is altered by nitrogen status

OpenAIRE

Cechin, Inês; Gonzalez, Gisely Cristina; Corniani, Natália; Fumis, Terezinha de Fátima

2018-01-01

ABSTRACT: Interaction effects between nitrogen and UV-B radiation were studied in sunflower (Helianthus annuus L. variety IAC-Iarama) plants grown in a greenhouse under natural photoperiod conditions. Plants were irradiated with 0.8W m-2 (control) or 8.0W m-2 (+UV-B) of UV-B radiation for 7h per day. The plants were grown in pots containing vermiculite and watered with 70% of full strength nitrogen-free Long Ashton solution, containing either low (42.3ppm) or high (282ppm) nitrogen as ammoniu...

Variations in constitutive and inducible UV-B tolerance; dissecting photosystem II protection in Arabidopsis thaliana accessions

NARCIS (Netherlands)

Jansen, M.A.K.; LeMartret, B.; Koornneef, M.

2010-01-01

The rise in ultraviolet-B (UV-B) (280–315 nm) radiation levels, that is a consequence of stratospheric ozone layer depletion, has triggered extensive research on the effects of UV-B on plants. Plants raised under natural sunlight conditions are generally well protected from the potentially harmful

A comparison of UVb compact lamps in enabling cutaneous vitamin D synthesis in growing bearded dragons

NARCIS (Netherlands)

Diehl, J.J.E.; Baines, F.M.; Heijboer, A.C.; Leeuwen, van J.P.; Kik, M.; Hendriks, W.H.; Oonincx, D.G.A.B.

2018-01-01

The effect of exposure to different UVb compact lamps on the vitamin D status of growing bearded dragons (Pogona vitticeps) was studied. Forty-two newly hatched bearded dragons (<24 h old) were allocated to six treatment groups (n = 7 per group). Five groups were exposed to different UVb

A comparison of UVb compact lamps in enabling cutaneous vitamin D synthesis in growing bearded dragons

NARCIS (Netherlands)

Diehl, J J E; Baines, F M; Heijboer, A C; van Leeuwen, J P; Kik, M; Hendriks, W H; Oonincx, D G A B

The effect of exposure to different UVb compact lamps on the vitamin D status of growing bearded dragons (Pogona vitticeps) was studied. Forty-two newly hatched bearded dragons (<24 h old) were allocated to six treatment groups (n = 7 per group). Five groups were exposed to different UVb compact

Cyanidin-3-glucoside inhibits UVB-induced oxidative damage and inflammation by regulating MAP kinase and NF-κB signaling pathways in SKH-1 hairless mice skin

International Nuclear Information System (INIS)

Pratheeshkumar, Poyil; Son, Young-Ok; Wang, Xin; Divya, Sasidharan Padmaja; Joseph, Binoy; Hitron, John Andrew; Wang, Lei; Kim, Donghern; Yin, Yuanqin; Roy, Ram Vinod; Lu, Jian; Zhang, Zhuo; Wang, Yitao

2014-01-01

Skin cancer is one of the most commonly diagnosed cancers in the United States. Exposure to ultraviolet-B (UVB) radiation induces inflammation and photocarcinogenesis in mammalian skin. Cyanidin-3-glucoside (C3G), a member of the anthocyanin family, is present in various vegetables and fruits especially in edible berries, and displays potent antioxidant and anticarcinogenic properties. In this study, we have assessed the in vivo effects of C3G on UVB irradiation induced chronic inflammatory responses in SKH-1 hairless mice, a well-established model for UVB-induced skin carcinogenesis. Here, we show that C3G inhibited UVB-induced skin damage and inflammation in SKH-1 hairless mice. Our results indicate that C3G inhibited glutathione depletion, lipid peroxidation and myeloperoxidation in mouse skin by chronic UVB exposure. C3G significantly decreased the production of UVB-induced pro-inflammatory cytokines, such as IL-6 and TNF-α, associated with cutaneous inflammation. Likewise, UVB-induced inflammatory responses were diminished by C3G as observed by a remarkable reduction in the levels of phosphorylated MAP kinases, Erk1/2, p38, JNK1/2 and MKK4. Furthermore, C3G also decreased UVB-induced cyclooxygenase-2 (COX-2), PGE 2 and iNOS levels, which are well-known key mediators of inflammation and cancer. Treatment with C3G inhibited UVB-induced nuclear translocation of NF-κB and degradation of IκBα in mice skin. Immunofluorescence assay revealed that topical application of C3G inhibited the expression of 8-hydroxy-2′-deoxyguanosine, proliferating cell nuclear antigen, and cyclin D1 in chronic UVB exposed mouse skin. Collectively, these data indicates that C3G can provide substantial protection against the adverse effects of UVB radiation by modulating UVB-induced MAP kinase and NF-κB signaling pathways. - Highlights: • C3G inhibited UVB-induced oxidative damage and inflammation. • C3G inhibited UVB-induced COX-2, iNOS and PGE 2 production. • C3G inhibited

Cyanidin-3-glucoside inhibits UVB-induced oxidative damage and inflammation by regulating MAP kinase and NF-κB signaling pathways in SKH-1 hairless mice skin

Energy Technology Data Exchange (ETDEWEB)

Pratheeshkumar, Poyil; Son, Young-Ok; Wang, Xin; Divya, Sasidharan Padmaja [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Joseph, Binoy [Spinal Cord and Brain Injury Research Center and Department of Physiology, University of Kentucky, Lexington, KY 40536-0509 (United States); Hitron, John Andrew; Wang, Lei [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Kim, Donghern [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Yin, Yuanqin [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Cancer Institute, The First Affiliated Hospital, China Medical University, Shenyang (China); Roy, Ram Vinod [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Lu, Jian [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Institute of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Zhang, Zhuo [Graduate Center for Toxicology, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Wang, Yitao [State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau (China); and others

2014-10-01

Skin cancer is one of the most commonly diagnosed cancers in the United States. Exposure to ultraviolet-B (UVB) radiation induces inflammation and photocarcinogenesis in mammalian skin. Cyanidin-3-glucoside (C3G), a member of the anthocyanin family, is present in various vegetables and fruits especially in edible berries, and displays potent antioxidant and anticarcinogenic properties. In this study, we have assessed the in vivo effects of C3G on UVB irradiation induced chronic inflammatory responses in SKH-1 hairless mice, a well-established model for UVB-induced skin carcinogenesis. Here, we show that C3G inhibited UVB-induced skin damage and inflammation in SKH-1 hairless mice. Our results indicate that C3G inhibited glutathione depletion, lipid peroxidation and myeloperoxidation in mouse skin by chronic UVB exposure. C3G significantly decreased the production of UVB-induced pro-inflammatory cytokines, such as IL-6 and TNF-α, associated with cutaneous inflammation. Likewise, UVB-induced inflammatory responses were diminished by C3G as observed by a remarkable reduction in the levels of phosphorylated MAP kinases, Erk1/2, p38, JNK1/2 and MKK4. Furthermore, C3G also decreased UVB-induced cyclooxygenase-2 (COX-2), PGE{sub 2} and iNOS levels, which are well-known key mediators of inflammation and cancer. Treatment with C3G inhibited UVB-induced nuclear translocation of NF-κB and degradation of IκBα in mice skin. Immunofluorescence assay revealed that topical application of C3G inhibited the expression of 8-hydroxy-2′-deoxyguanosine, proliferating cell nuclear antigen, and cyclin D1 in chronic UVB exposed mouse skin. Collectively, these data indicates that C3G can provide substantial protection against the adverse effects of UVB radiation by modulating UVB-induced MAP kinase and NF-κB signaling pathways. - Highlights: • C3G inhibited UVB-induced oxidative damage and inflammation. • C3G inhibited UVB-induced COX-2, iNOS and PGE{sub 2} production. • C3G

Recovery Effects of Oral Administration of Glucosylceramide and Beet Extract on Skin Barrier Destruction by UVB in Hairless Mice

Directory of Open Access Journals (Sweden)

Yoshihiro Tokudome

2017-10-01

Full Text Available Purified glucosylceramide from beet extract (beet GlcCer and beet extract containing an equal amount of GlcCer were administered orally to ultra violet B (UVB-irradiated mice, and differences in the protective effects against skin barrier dysfunction caused by UVB irradiation were compared. In the beet GlcCer group, epidermal thickening and the decrease in stratum corneum (SC ceramide content caused by UVB irradiation were reduced. In the group that was orally administered beet extract containing glucosylceramide, effects similar to those in the beet GlcCer group were observed. Oral administration of beet GlcCer had no obvious effects against an increase in TEWL or decrease in SC water content after UVB irradiation, but there was improvement in the beet extract group. Oral administration of beet GlcCer is effective in improving skin barrier function in UVB-irradiated mice. Beet extract contains constituents other than GlcCer that are also effective in improving skin barrier function.

Field measurements of the global UV-B radiation: a comparison between a broad-band radiometer and a Brewer spectrophotometer

International Nuclear Information System (INIS)

Anav, A.; Moriconi, M.L.; Di Menno, M.; Giannoccolo, S.

1996-01-01

The spectral responsivity shape plays an important role in the prospect of a wide use of broad-band meters in the UV-B monitoring. As most UV-B broad-band meters have a responsivity approximating an erythemal action spectrum, a measurement campaign was planned to verify if such an instrument could be successfully used to measure the unfiltered global irradiance. A Yankee radiometer mod. UV-B 1 and a Brewer spectrophotometer, considered as a reference meter, were compared for this purpose. A short theoretical treatment of the Yankee radiometer response and some results of the comparison are shown. Only clear-sky days data are selected so that the UV-B radiation reaching the ground could be modelled as the sum of the direct and isotropic diffuse components. The comparison results show a good agreement between the two instruments and confirm the capability of a broad-band UV-B radiometer of correctly measuring the global irradiance

Variations in constitutive and inducible UV-B tolerance; dissecting photosystem II protection in Arabidopsis thaliana accessions.

Science.gov (United States)

Jansen, Marcel A K; Martret, Bénedicte Le; Koornneef, Maarten

2010-01-01

The rise in ultraviolet-B (UV-B) (280-315 nm) radiation levels, that is a consequence of stratospheric ozone layer depletion, has triggered extensive research on the effects of UV-B on plants. Plants raised under natural sunlight conditions are generally well protected from the potentially harmful effects of UV-B radiation. However, it is mostly unknown to which extent UV protection is constitutive and/or induced. In this study, we have analysed the role of constitutive and inducible protection responses in avoiding UV-B damage to photosystem II of photosynthesis. We have assayed the UV susceptibility of photosystem II in 224 Arabidopsis thaliana accessions from across the Northern hemisphere, and found a continuum of constitutive UV-protection levels, with some accessions being UV sensitive and others UV tolerant. Statistical analysis showed only very weak associations between constitutive UV tolerance and the geographic origin of accessions. Instead, most of the variance in constitutive UV-B protection of photosynthesis is present at the level of local Arabidopsis populations originating in the same geographic and climatic area. The variance in constitutive UV protection is, however, small compared to the amplitude of environmentally induced changes in UV protection. Thus, our data emphasise the importance of inducible responses for the protection of photosystem II against UV-B. Remarkably, the conditions that induce UV-protective responses vary; accessions from lower latitudes were found to switch-on UV defences more readily than those of higher latitudes. Such altered regulation of induction may comprise a suitable adaptation response when levels of a stressor are fluctuating in the short term, but predictable over longer periods.

UVB-induced nuclear translocation of TC-PTP by AKT/14-3-3σ axis inhibits keratinocyte survival and proliferation.

Science.gov (United States)

Kim, Mihwa; Morales, Liza D; Baek, Minwoo; Slaga, Thomas J; DiGiovanni, John; Kim, Dae Joon

2017-10-31

Understanding protein subcellular localization is important to determining the functional role of specific proteins. T-cell protein tyrosine phosphatase (TC-PTP) contains bipartite nuclear localization signals (NLSI and NLSII) in its C-terminus. We previously have demonstrated that the nuclear form of TC-PTP (TC45) is mainly localized to the cytoplasm in keratinocytes and it is translocated to the nucleus following UVB irradiation. Here, we report that TC45 is translocated by an AKT/14-3-3σ-mediated mechanism in response to UVB exposure, resulting in increased apoptosis and decreased keratinocyte proliferation. We demonstrate that UVB irradiation increased phosphorylation of AKT and induced nuclear translocation of 14-3-3σ and TC45. However, inhibition of AKT blocked nuclear translocation of TC45 and 14-3-3σ. Site-directed mutagenesis of 14-3-3σ binding sites within TC45 showed that a substitution at Threonine 179 (TC45/T179A) effectively blocked UVB-induced nuclear translocation of ectopic TC45 due to the disruption of the direct binding between TC45 and 14-3-3σ. Overexpression of TC45/T179A in keratinocytes resulted in a decrease of UVB-induced apoptosis which corresponded to an increase in nuclear phosphorylated STAT3, and cell proliferation was higher in TC45/T179A-overexpressing keratinocytes compared to control keratinocytes following UVB irradiation. Furthermore, deletion of TC45 NLSII blocked its UVB-induced nuclear translocation, indicating that both T179 and NLSII are required. Taken together, our findings suggest that AKT and 14-3-3σ cooperatively regulate TC45 nuclear translocation in a critical step of an early protective mechanism against UVB exposure that signals the deactivation of STAT3 in order to promote keratinocyte cell death and inhibit keratinocyte proliferation.

Interference of silibinin with IGF-1R signalling pathways protects human epidermoid carcinoma A431 cells from UVB-induced apoptosis

International Nuclear Information System (INIS)

Liu, Weiwei; Otkur, Wuxiyar; Li, Lingzhi; Wang, Qiong; He, Hao; Zang, Linghe; Hayashi, Toshihiko; Tashiro, Shin-ichi; Onodera, Satoshi; Xia, Mingyu; Ikejima, Takashi

2013-01-01

Highlights: ► Silibinin protects A431 cells from UVB irradiation-induced apoptosis. ► Up-regulation of the IGF-1R-JNK/ERK pathways by UVB induces cell apoptosis. ► Silibinin inhibits IGF-1R pathways to repress caspase-8-mediated apoptosis. -- Abstract: Ultraviolet B (UVB) from sunlight is a major cause of cutaneous lesion. Silibinin, a traditional hepatic protectant, elicits protective effects against UVB-induced cellular damage. In A431 cells, the insulin-like growth factor-1 receptor (IGF-1R) was markedly up-regulated by UVB irradiation. The activation of the IGF-1R signalling pathways contributed to apoptosis of the cells rather than rescuing the cells from death. Up-regulated IGF-1R stimulated downstream mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinases (JNK) and extracellular signal-regulated protein kinases 1/2 (ERK1/2). The subsequent activation of caspase-8 and caspase-3 led to apoptosis. The activation of IGF-1R signalling pathways is the cause of A431 cell death. The pharmacological inhibitors and the small interfering RNA (siRNA) targeting IGF-1R suppressed the downstream activation of JNK/ERK-caspases to help the survival of the UVB-irradiated A431 cells. Indeed, silibinin treatment suppressed the IGF-1R-JNK/ERK pathways and thus protected the cells from UVB-induced apoptosis

Drug delivery strategies for chemoprevention of UVB-induced skin cancer: A review.

Science.gov (United States)

Bagde, Arvind; Mondal, Arindam; Singh, Mandip

2018-01-01

Annually, more skin cancer cases are diagnosed than the collective incidence of the colon, lung, breast, and prostate cancer. Persistent contact with sunlight is a primary cause for all the skin malignancies. UVB radiation induces reactive oxygen species (ROS) production in the skin which eventually leads to DNA damage and mutation. Various delivery approaches for the skin cancer treatment/prevention have been evolving and are directed toward improvements in terms of delivery modes, therapeutic agents, and site-specificity of therapeutics delivery. The effective chemoprevention activity achieved is based on the efficiency of the delivery system used and the amount of the therapeutic molecule deposited in the skin. In this article, we have discussed different studies performed specifically for the chemoprevention of UVB-induced skin cancer. Ultra-flexible nanocarriers, transethosomes nanocarriers, silica nanoparticles, silver nanoparticles, nanocapsule suspensions, microemulsion, nanoemulsion, and polymeric nanoparticles which have been used so far to deliver the desired drug molecule for preventing the UVB-induced skin cancer. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of UV-B irradiated algae on zooplankton grazing

NARCIS (Netherlands)

Lange, de H.J.; Lürling, M.F.L.L.W.

2003-01-01

We tested the effects of UV-B stressed algae on grazing rates of zooplankton. Four algal species ( Chlamydomonas reinhardtii, Cryptomonas sp., Scenedesmus obliquus and Microcystis aeruginosa) were used as food and fed to three zooplankton species ( Daphnia galeata, Bosmina longirostris and

A thirty percent increase in UV-B has no impact on photosynthesis in well-watered and droughted pea plants in the field

International Nuclear Information System (INIS)

Allen, D.J.; Nogues, S.; Morison, J.I.L.; Greenslade, P.D.; McLeod, A.R.; Baker, N.R.

1999-01-01

It has been suggested that field experiments which increase UV-B irradiation by a fixed amount irrespective of ambient light conditions (‘square-wave’), may overestimate the response of photosynthesis to UV-B irradiation. In this study, pea (Pisum sativum L.) plants were grown in the field and subjected to a modulated 30% increase in ambient UK summer UV-B radiation (weighted with an erythemal action spectrum) and a mild drought treatment. UV-A and ambient UV control treatments were also studied. There were no significant effects of the UV-B treatment on the in situ CO 2 assimilation rate throughout the day or on the light-saturated steady-state photosynthesis. This was confirmed by an absence of UV-B effects on the major components contributing to CO 2 assimilation; photosystem II electron transport, ribulose 1,5-bisphosphate regeneration, ribulose 1,5-bisphosphate carboxylase/oxygenase carboxylation, and stomatal conductance. In addition to the absence of an effect on photosynthetic activities, UV-B had no significant impact on plant biomass, leaf area or partitioning. UV-B exposure increased leaf flavonoid content. The UV-A treatment had no observable effect on photosynthesis or productivity. Mild drought resulted in reduced biomass, a change in partitioning away from shoots to roots whilst maintaining leaf area, but had no observable effect on photosynthetic competence. No UV-B and drought treatment interactions were observed on photosynthesis or plant biomass. In conclusion, a 30% increase in UV-B had no effects on photosynthetic performance or productivity in well-watered or droughted pea plants in the field. (author)

Effects of UV-B radiation on leaf hair traits of invasive plants-Combining historical herbarium records with novel remote sensing data.

Science.gov (United States)

Václavík, Tomáš; Beckmann, Michael; Cord, Anna F; Bindewald, Anja M

2017-01-01

Ultraviolet-B (UV-B) radiation is a key but under-researched environmental factor that initiates diverse responses in plants, potentially affecting their distribution. To date, only a few macroecological studies have examined adaptations of plant species to different levels of UV-B. Here, we combined herbarium specimens of Hieracium pilosella L. and Echium vulgare L. with a novel UV-B dataset to examine differences in leaf hair traits between the plants' native and alien ranges. We analysed scans of 336 herbarium specimens using standardized measurements of leaf area, hair density (both species) and hair length (H. pilosella only). While accounting for other bioclimatic variables (i.e. temperature, precipitation) and effects of herbivory, we examined whether UV-B exposure explains the variability and geographical distribution of these traits in the native (Northern Hemisphere) vs. the alien (Southern Hemisphere) range. UV-B explained the largest proportion of the variability and geographical distribution of hair length in H. pilosella (relative influence 67.1%), and hair density in E. vulgare (66.2%). Corresponding with higher UV-B, foliar hairs were 25% longer for H. pilosella and 25% denser for E. vulgare in records from the Southern as compared to those from the Northern Hemisphere. However, focusing on each hemisphere separately or controlling for its effect in a regression analysis, we found no apparent influence of UV-B radiation on hair traits. Thus, our findings did not confirm previous experimental studies which suggested that foliar hairs may respond to higher UV-B intensities, presumably offering protection against detrimental levels of radiation. We cannot rule out UV-B radiation as a possible driver because UV-B radiation was the only considered variable that differed substantially between the hemispheres, while bioclimatic conditions (e.g. temperature, precipitation) and other considered variables (herbivory damage, collection date) were at similar

Effects of UV-B radiation on leaf hair traits of invasive plants—Combining historical herbarium records with novel remote sensing data

Science.gov (United States)

Cord, Anna F.; Bindewald, Anja M.

2017-01-01

Ultraviolet-B (UV-B) radiation is a key but under-researched environmental factor that initiates diverse responses in plants, potentially affecting their distribution. To date, only a few macroecological studies have examined adaptations of plant species to different levels of UV-B. Here, we combined herbarium specimens of Hieracium pilosella L. and Echium vulgare L. with a novel UV-B dataset to examine differences in leaf hair traits between the plants’ native and alien ranges. We analysed scans of 336 herbarium specimens using standardized measurements of leaf area, hair density (both species) and hair length (H. pilosella only). While accounting for other bioclimatic variables (i.e. temperature, precipitation) and effects of herbivory, we examined whether UV-B exposure explains the variability and geographical distribution of these traits in the native (Northern Hemisphere) vs. the alien (Southern Hemisphere) range. UV-B explained the largest proportion of the variability and geographical distribution of hair length in H. pilosella (relative influence 67.1%), and hair density in E. vulgare (66.2%). Corresponding with higher UV-B, foliar hairs were 25% longer for H. pilosella and 25% denser for E. vulgare in records from the Southern as compared to those from the Northern Hemisphere. However, focusing on each hemisphere separately or controlling for its effect in a regression analysis, we found no apparent influence of UV-B radiation on hair traits. Thus, our findings did not confirm previous experimental studies which suggested that foliar hairs may respond to higher UV-B intensities, presumably offering protection against detrimental levels of radiation. We cannot rule out UV-B radiation as a possible driver because UV-B radiation was the only considered variable that differed substantially between the hemispheres, while bioclimatic conditions (e.g. temperature, precipitation) and other considered variables (herbivory damage, collection date) were at similar

Effects of UV-B radiation on leaf hair traits of invasive plants-Combining historical herbarium records with novel remote sensing data.

Directory of Open Access Journals (Sweden)

Tomáš Václavík

Full Text Available Ultraviolet-B (UV-B radiation is a key but under-researched environmental factor that initiates diverse responses in plants, potentially affecting their distribution. To date, only a few macroecological studies have examined adaptations of plant species to different levels of UV-B. Here, we combined herbarium specimens of Hieracium pilosella L. and Echium vulgare L. with a novel UV-B dataset to examine differences in leaf hair traits between the plants' native and alien ranges. We analysed scans of 336 herbarium specimens using standardized measurements of leaf area, hair density (both species and hair length (H. pilosella only. While accounting for other bioclimatic variables (i.e. temperature, precipitation and effects of herbivory, we examined whether UV-B exposure explains the variability and geographical distribution of these traits in the native (Northern Hemisphere vs. the alien (Southern Hemisphere range. UV-B explained the largest proportion of the variability and geographical distribution of hair length in H. pilosella (relative influence 67.1%, and hair density in E. vulgare (66.2%. Corresponding with higher UV-B, foliar hairs were 25% longer for H. pilosella and 25% denser for E. vulgare in records from the Southern as compared to those from the Northern Hemisphere. However, focusing on each hemisphere separately or controlling for its effect in a regression analysis, we found no apparent influence of UV-B radiation on hair traits. Thus, our findings did not confirm previous experimental studies which suggested that foliar hairs may respond to higher UV-B intensities, presumably offering protection against detrimental levels of radiation. We cannot rule out UV-B radiation as a possible driver because UV-B radiation was the only considered variable that differed substantially between the hemispheres, while bioclimatic conditions (e.g. temperature, precipitation and other considered variables (herbivory damage, collection date were at

On the interaction of UV-B radiation (280-315 mm) with water stress in crop plants

International Nuclear Information System (INIS)

Balakumar, T.; Vincent, V.H.B.; Paliwal, K.

1993-01-01

Cowpea (Vigna unguiculata L. Walp.) seedlings (3-day-old) were subjected to 4 kinds of experimental treatments: (1) control without exposure to any stress (-D-UV), (2) moderate water stress with no UV-B irradiation (+D-UV), (3) no water stress but exposure to UV-B radiation (-D+UV), and (4) moderate water stress and exposure to UV-B (+D+UV). UV-B and drought stress in the combined form elicited beneficial effects on the morphological and growth characteristics, and a few additive inhibitory effects in some functional processes. An increase in the specific leaf weight (SLW) was observed in the combination of stresses, which could be a defence mechanism against UV-B. The combination of stresses promoted the synthesis of anthocyanins and phenolic compounds. The responses of plants to the combination of stresses indicate that during simultaneous exposure of plants to multiple stresses, one form of stress could minimize the damage by the other. The enhancement of superoxide dismutase (SOD) and catalase activities appear to serve as acclimation mechanisms to scavenge the toxic, free radicals of oxygen produced under stress conditions. However, the inhibition in nitrate metabolism was greater in the combined stresses than in either of the stresses imposed separately. The results of this study illustrate that the interaction of stresses during simultaneous multiple stress conditions brings out certain beneficial effects. (author)

He-Ne laser treatment improves the photosynthetic efficiency of wheat exposed to enhanced UV-B radiation

International Nuclear Information System (INIS)

Chen, Huize; Han, Rong

2014-01-01

The level of ultraviolet-B (UV-B) radiation on the Earth’s surface has increased due to depletion of the ozone layer. Here, we explored the effects of continuous wave He-Ne laser irradiation (632 nm, 5 mW mm –2 , 2 min d –1 ) on the physiological indexes of wheat seedlings exposed to enhanced UV-B radiation (10 KJ m –2 d –1 ) at the early growth stages. Wheat seedlings were irradiated with enhanced UV-B, He-Ne laser treatment or a combination of the two. Enhanced UV-B radiation had deleterious effects on wheat photosynthesis parameters including photosystem II (chlorophyll content, Hill reaction, chlorophyll fluorescence parameters, electron transport rate (ETR), and yield), the thylakoid (optical absorption ability, cyclic photophosphorylation, Mg 2+ -ATPase, and Ca 2+ -ATPase) and some enzymes in the dark reaction (phosphoenolpyruvate carboxylase (PEPC), carbonic anhydrase (CA), malic dehydrogenase (MDH), and chlorophyllase). These parameters were improved in UV-B-exposed wheat treated with He-Ne laser irradiation; the parameters were near control levels and the enzyme activities increased, suggesting that He-Ne laser treatment partially alleviates the injury caused by enhanced UV-B irradiation. Furthermore, the use of He-Ne laser alone had a favourable effect on seedling photosynthesis compared with the control. Therefore, He-Ne laser irradiation can enhance the adaptation capacity of crops. (paper)

Fisetin inhibits UVB-induced cutaneous inflammation and activation of PI3K/AKT/NFκB signaling pathways in SKH-1 hairless mice†

Science.gov (United States)

Pal, Harish Chandra; Athar, Mohammad; Elmets, Craig A.; Afaq, Farrukh

2014-01-01

Solar ultraviolet B (UVB) radiation has been shown to induce inflammation, DNA damage, p53 mutations, and alterations in signaling pathways eventually leading to skin cancer. In the present study, we investigated whether fisetin reduces inflammatory responses and modulates PI3K/AKT/NFκB cell survival signaling pathways in UVB exposed SKH-1 hairless mouse skin. Mice were exposed to 180 mJ/cm2 of UVB radiation on alternate days for a total of seven exposures, and fisetin (250 and 500 nmol) was applied topically after 15 min of each UVB exposure. Fisetin treatment to UVB exposed mice resulted in decreased hyperplasia and reduced infiltration of inflammatory cells. Fisetin treatment also reduced inflammatory mediators such as COX-2, PGE2 as well as its receptors (EP1- EP4), and MPO activity. Furthermore, fisetin reduced the level of inflammatory cytokines TNFα, IL-1β and IL-6 in UVB exposed skin. Fisetin treatment also reduced cell proliferation markers as well as DNA damage as evidenced by increased expression of p53 and p21 proteins. Further studies revealed that fisetin inhibited UVB-induced expression of PI3K, phosphorylation of AKT, and activation of the NFκB signaling pathway in mouse skin. Overall, these data suggest that fisetin may be useful against UVB-induced cutaneous inflammation and DNA damage. PMID:25169110

Fisetin inhibits UVB-induced cutaneous inflammation and activation of PI3K/AKT/NFκB signaling pathways in SKH-1 hairless mice.

Science.gov (United States)

Pal, Harish Chandra; Athar, Mohammad; Elmets, Craig A; Afaq, Farrukh

2015-01-01

Solar ultraviolet B (UVB) radiation has been shown to induce inflammation, DNA damage, p53 mutations and alterations in signaling pathways eventually leading to skin cancer. In this study, we investigated whether fisetin reduces inflammatory responses and modulates PI3K/AKT/NFκB cell survival signaling pathways in UVB-exposed SKH-1 hairless mouse skin. Mice were exposed to 180 mJ cm(-2) of UVB radiation on alternate days for a total of seven exposures, and fisetin (250 and 500 nmol) was applied topically after 15 min of each UVB exposure. Fisetin treatment to UVB-exposed mice resulted in decreased hyperplasia and reduced infiltration of inflammatory cells. Fisetin treatment also reduced inflammatory mediators such as COX-2, PGE2 as well as its receptors (EP1-EP4) and MPO activity. Furthermore, fisetin reduced the level of inflammatory cytokines TNFα, IL-1β and IL-6 in UVB-exposed skin. Fisetin treatment also reduced cell proliferation markers as well as DNA damage as evidenced by increased expression of p53 and p21 proteins. Further studies revealed that fisetin inhibited UVB-induced expression of PI3K, phosphorylation of AKT and activation of the NFκB signaling pathway in mouse skin. Overall, these data suggest that fisetin may be useful against UVB-induced cutaneous inflammation and DNA damage. © 2014 The American Society of Photobiology.

Attenuation of UV-B exposure-induced inflammation by abalone hypobranchial gland and gill extracts.

Science.gov (United States)

Kuanpradit, Chitraporn; Jaisin, Yamaratee; Jungudomjaroen, Sumon; Akter Mitu, Shahida; Puttikamonkul, Srisombat; Sobhon, Prasert; Cummins, Scott F

2017-05-01

Exposure to solar ultraviolet B (UV-B) is a known causative factor for many skin complications such as wrinkles, black spots, shedding and inflammation. Within the wavelengths 280‑320 nm, UV-B can penetrate to the epidermal level. This investigation aimed to test whether extracts from the tropical abalone [Haliotis asinina (H. asinina)] mucus-secreting tissues, the hypobranchial gland (HBG) and gills, were able to attenuate the inflammatory process, using the human keratinocyte HaCaT cell line. Cytotoxicity of abalone tissue extracts was determined using an AlamarBlue viability assay. Results showed that HaCaT cells could survive when incubated in crude HBG and gill extracts at concentrations between abalone extract from both the HBG and gill (0, 0.1, 2.5, 5 µg/ml). A significant increase in cell viability was observed (P2.5 µg/ml extract showed a significant decrease in intensity for COX‑2, phospho‑p38 and phospho‑SPK/JNK. The present study demonstrated that abalone extracts from the HGB and gill can attenuate inflammatory proteins triggered by UV-B. Hence, the contents of abalone extract, including cellmetabolites and peptides, may provide new agents for skin anti‑inflammation, preventing damage due to UV-B.

Radiation sources providing increased UVA/UVB ratios induce photoprotection dependent on the UVA dose in hairless mice.

Science.gov (United States)

Reeve, Vivienne E; Domanski, Diane; Slater, Michael

2006-01-01

In studies involving mice in which doses of UVA (320-400 nm) and UVB (290-320 nm) radiation were administered alone or combined sequentially, we observed a protective effect of UVA against UVB-induced erythema/edema and systemic suppression of contact hypersensitivity. The UVA immunoprotection was mediated by the induction of the stress enzyme heme oxygenase-1 (HO-1) in the skin, protection of the cutaneous Th1 cytokines interferon-gamma (IFN-gamma) and IL-12 and inhibition of the UVB-induced expression of the Th2 cytokine IL-10. In this study, we seek evidence for an immunological waveband interaction when UVA and UVB are administered concurrently to hairless mice as occurs during sunlight exposure in humans. A series of spectra providing varying ratios of UVA/UVB were developed, with the UVA ratio increased to approximately 3.5 times the UVA component in solar simulated UV (SSUV). We report that progressively increasing the UVA component of the radiation while maintaining a constant UVB dose resulted in a reduction of both the erythema/edema reaction and the degree of systemic immunosuppression, as measured as contact hypersensitivity. The UVA-enhanced immunoprotection was abrogated in mice treated with a specific HO enzyme inhibitor. UVA-enhanced radiation also upregulated the expression of cutaneous IFN-gamma and IL-12 and inhibited expression of both IL-6 and IL-10, compared with the activity of SSUV. The results were consistent with the previously characterized mechanisms of photoprotection by the UVA waveband alone and suggest that the UVA component of solar UV may have beneficial properties for humans.

Salubrinal protects human skin fibroblasts against UVB-induced cell death by blocking endoplasmic reticulum (ER) stress and regulating calcium homeostasis.

Science.gov (United States)

Ji, Chao; Yang, Bo; Huang, Shu-Ying; Huang, Jin-Wen; Cheng, Bo

2017-12-02

The role of UVB in skin photo damages has been widely reported. Overexposure to UVB will induce severe DNA damages in epidermal cells and cause most cytotoxic symptoms. In the present study, we tested the potential activity of salubrinal, a selective inhibitor of Eukaryotic Initiation Factor 2 (eIF2) -alpha phosphatase, against UV-induced skin cell damages. We first exposed human fibroblasts to UVB radiation and evaluated the cytosolic Ca 2+ level as well as the induction of ER stress. We found that UVB radiation induced the depletion of ER Ca 2+ and increased the expression of ER stress marker including phosphorylated PERK, CHOP, and phosphorylated IRE1α. We then determined the effects of salubrinal in skin cell death induced by UVB radiation. We observed that cells pre-treated with salubrinal had a higher survival rate compared to cells treated with UVB alone. Pre-treatment with salubrinal successfully re-established the ER function and Ca 2+ homeostasis. Our results suggest that salubrinal can be a potential therapeutic agents used in preventing photoaging and photo damages. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluating the effects of UV-B and UV-A irradiances on plant pigments, photosynthesis and growth in Glycine max L

International Nuclear Information System (INIS)

Middleton, E.H.M.

1993-01-01

Increasing penetration of UV-B radiation to the earth's surface resulting from stratospheric ozone depletion is an important environmental concern, but plant response to UV-B irradiation has been difficult to assess. The UV-A irradiance has not been specifically measured or controlled previously. The experimental UV-A was controlled in a series of three glasshouse experiments conducted under high photosynthetic photon flux (midday PPF ≥ 1200 μmol m -2 s -1 ). Low (LT) and High (HT) daily UV-B BE irradiances (10.7; 14.1 kJ m -2 ) were utilized in two experiments, whereas treatments with different UV-B BE :UV-A ratios ( BE :UV-A ratios

Effects of UV-B radiation on microcystin production of a toxic strain of Microcystis aeruginosa and its competitiveness against a non-toxic strain

International Nuclear Information System (INIS)

Yang, Zhen; Kong, Fanxiang; Shi, Xiaoli; Yu, Yang; Zhang, Min

2015-01-01

Highlights: • UV-B radiation showed higher inhibition to non-toxin producing than toxin-producing strains on growth and photosynthetic activity. • Both intracellular and extracellular MC contents decreased markedly under UV-B radiation. • Higher resistance to UV-B radiation helped toxin-producing M. aeruginosa to predominate in the competition. - Abstract: Microcystins (MCs) produced by toxic cyanobacteria pose a health hazard to humans and animals. Some environmental factors can alter the MC concentrations by affecting the abundance of toxin-producing strains in a cyanobacteria population and/or their toxin production. In this study, we designed a monoculture and competition experiment to investigate the impacts of UV-B radiation on MC production and the competition between toxin and non-toxin producing strains of Microcystis aeruginosa. UV-B radiation resulted in higher inhibition of the growth and photosynthetic activity of the non-toxin producing strain relative to that observed for the toxin-producing strain. Both intracellular and extracellular MC contents decreased markedly when the toxin-producing strain was exposed to UV-B radiation. In addition, a quantitative real-time PCR assay revealed that the ratio of toxin-producing M. aeruginosa under UV-B exposure was higher than that under PAR alone at an early stage of the experiment. However, its abundance under UV-B exposure was lower compared with the PAR alone treatment after day 12. Our study demonstrated that UV-B radiation has a great impact on the abundance of the toxin-producing strain in the Microcystis population and their toxin production, which suggests that the fluctuation of UV-B radiation affects the MC level of cyanobacteria blooms

Effects of UV-B radiation on microcystin production of a toxic strain of Microcystis aeruginosa and its competitiveness against a non-toxic strain

Energy Technology Data Exchange (ETDEWEB)

Yang, Zhen, E-mail: zhyang@niglas.ac.cn; Kong, Fanxiang, E-mail: fxkong@niglas.ac.cn; Shi, Xiaoli; Yu, Yang; Zhang, Min

2015-02-11

Highlights: • UV-B radiation showed higher inhibition to non-toxin producing than toxin-producing strains on growth and photosynthetic activity. • Both intracellular and extracellular MC contents decreased markedly under UV-B radiation. • Higher resistance to UV-B radiation helped toxin-producing M. aeruginosa to predominate in the competition. - Abstract: Microcystins (MCs) produced by toxic cyanobacteria pose a health hazard to humans and animals. Some environmental factors can alter the MC concentrations by affecting the abundance of toxin-producing strains in a cyanobacteria population and/or their toxin production. In this study, we designed a monoculture and competition experiment to investigate the impacts of UV-B radiation on MC production and the competition between toxin and non-toxin producing strains of Microcystis aeruginosa. UV-B radiation resulted in higher inhibition of the growth and photosynthetic activity of the non-toxin producing strain relative to that observed for the toxin-producing strain. Both intracellular and extracellular MC contents decreased markedly when the toxin-producing strain was exposed to UV-B radiation. In addition, a quantitative real-time PCR assay revealed that the ratio of toxin-producing M. aeruginosa under UV-B exposure was higher than that under PAR alone at an early stage of the experiment. However, its abundance under UV-B exposure was lower compared with the PAR alone treatment after day 12. Our study demonstrated that UV-B radiation has a great impact on the abundance of the toxin-producing strain in the Microcystis population and their toxin production, which suggests that the fluctuation of UV-B radiation affects the MC level of cyanobacteria blooms.

Malbec grape (Vitis vinifera L.) responses to the environment: Berry phenolics as influenced by solar UV-B, water deficit and sprayed abscisic acid.

Science.gov (United States)

Alonso, Rodrigo; Berli, Federico J; Fontana, Ariel; Piccoli, Patricia; Bottini, Rubén

2016-12-01

High-altitude vineyards receive elevated solar ultraviolet-B (UV-B) levels so producing high quality berries for winemaking because of induction in the synthesis of phenolic compounds. Water deficit (D) after veraison, is a commonly used tool to regulate berry polyphenols concentration in red wine cultivars. Abscisic acid (ABA) plays a crucial role in the acclimation to environmental factors/signals (including UV-B and D). The aim of the present study was to evaluate independent and interactive effects of high-altitude solar UV-B, moderate water deficit and ABA applications on Vitis vinifera cv. Malbec berries. The experiment was conducted during two growing seasons with two treatments of UV-B (+UV-B and -UV-B), watering (+D and -D) and ABA (+ABA and -ABA), in a factorial design. Berry fresh weight, sugar content, fruit yield, phenolic compounds profile and antioxidant capacity (ORAC) were analyzed at harvest. Previous incidence of high UV-B prevented deleterious effects of water deficit, i.e. berry weight reduction and diminution of sugar accumulation. High UV-B increased total phenols (mainly astilbin, quercetin and kaempferol) and ORAC, irrespectively of the combination with other factors. Fruit yield was reduced by combining water deficit and high UV-B or water deficit and ABA. Two applications of ABA were enough to induced biochemical changes increasing total anthocyanins, especially those with higher antioxidant capacity. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Protective effects of polyamines against UV-A and UV-B illumination in Physcia semipinnata thalli

Directory of Open Access Journals (Sweden)

Esmer Işıl

2017-04-01

Full Text Available The damage to DNA induced by UV-A and UV-B and protective effects of the polyamines putrescine (put, spermidine (spd and spermine (spm were investigated on the lichen Physcia semipinnata in the present study. Our results suggest that significant alterations of the photosynthetic quantum yield ratio occurred in response to increased UV-A and UV-B exposure time. The photosynthetic quantum yield ratio gradually decreased in P. semipinnata following exposure to UV-A and UV-B. Physcia semipinnata thalli which were treated with a polyamine in a concentration of 1 mM were not affected by UV-A exposure for 72 h. In the case of UV-B treatment, the protective polyamine dosage was 0.25 mM. We also used the random amplified polymorphic DNA (RAPD technique to detect DNA damage. The main changes observed in the RAPD profiles, which were obtained using 12 RAPD primers, were the appearance or disappearance of different bands and variation of their intensities. The use of at least three different primers allowed detection of specific band patterns in both UV-A- and UV-B-exposed samples treated with polyamines as compared to untreated ones.

Site and strand specificity of UVB mutagenesis in the SUP4-o gene of yeast

International Nuclear Information System (INIS)

Armstrong, J.D.; Kunz, B.A.

1990-01-01

DNA sequencing was used to characterize 208 mutations induced in the SUP4-o tRNA gene of the yeast Saccharomyces cerevisiae by UVB (285-320 nm) radiation. The results were compared to those for an analysis of 211 SUP4-o mutations induced by 254-nm UVC light. In each case, greater than 90% of the mutations were single base-pair changes but G.C----A.T transitions predominated and accounted for more of the mutations induced by UVB than UVC. Double substitutions, single base-pair deletions, and more complex events were also recovered. However, UVB induced 3-fold more tandem substitutions than UVC and nontandem double events were detected only after irradiation with UVC. Virtually all induced substitutions occurred at sites where the pyrimidine of the base pair was part of a dipyrimidine sequence. Although the site specificities were consistent with roles for cyclobutane dimers and pyrimidine-pyrimidone(6-4) lesions in mutation induction, preliminary photoreactivation data implicated cyclobutane dimers as the major form of premutational DNA damage for both agents. Intriguingly, there was a preference for both UVB- and UVC-induced mutations to occur at sites where the dipyrimidine was on the transcribed strand

Effect of UVB irradiation of the blood on cellular volume adherence and phagocytosis in probands and patients with multiple sclerosis

International Nuclear Information System (INIS)

Mix, E.; Jenssen, H.L.; Lehmitz, R.; Buddenhagen, F.; Hitzschke, B.; Richter, M.

1988-01-01

UVB-induced changes of blood cell properties were investigated in 12 multiple sclerosis (MS) patients and in 10 healthy volunteers. The mean cell volume (MCV) was determined by electronic sizing, the granulocyte and lymphocyte adherence was estimated in a capillary assay, and the phagocytic activity of granulocytes was measured in a test system based on the incorporation of opsonized baker's yeast. In MS patients the MCV of red cells and lymphocytes decreased rapidly within 6 UVB treatments. In contrast, the reduction of the granulocyte volume was delayed (between the 6th and 12th UVB). In the control group the mean value of the red cell and lymphocyte MCV remained rather unaffected. There was a slight rise of the granulocyte volume after the 6th UVB. The only significant change of adherence was an increase of granulocyte adherence in MS patients. Untreated patients had a significantly enhanced phagocytic activity in comparison to the control group. 6 UVB treatments induced a singificant reduction of the phagocytic activity in MS patients. However, subsequently the percentage of phagocytizing cells increased again, whereas the particle uptake per cell continued to decrease. In the control group only minor UVB-induced changes of phagocytosis were observed. The in vitro UV irradiation caused an enhanced phagocytosis in the majority of cases in both controls and MS patients. In general, under the UVB treatment all parameters examined changed in the sense of a normalisation, in that the measured values reached a new level lying between the extreme pretreatment values accompanied by a reduced standard deviation. The effect of UVB was more pronounced in MS patients when compared with normal control. This could result from an enhanced sensitivity to the influence of UVB of pathologically altered cells in MS patients. The monitoring of the MCV of red cells and lymphocytes as well as the repeated testing of granulocyte phagocytosis are recommended for supportion of therapy

Epigallocatechin-gallate (EGCG) regulates autophagy in human retinal pigment epithelial cells: A potential role for reducing UVB light-induced retinal damage

International Nuclear Information System (INIS)

Li, Chao-Peng; Yao, Jin; Tao, Zhi-Fu; Li, Xiu-Miao; Jiang, Qin; Yan, Biao

2013-01-01

Highlights: •UVB irradiation induces RPE autophagy. •EGCG treatment represses UVB-mediated autophagy. •EGCG regulates UVB-mediated autophagy through mTOR signaling pathway. •EGCG sensitizes RPE cells to UVB-induced damage in an autophagy-dependent manner. -- Abstract: Autophagy is an intracellular catabolic process involved in protein and organelle degradation via the lysosomal pathway that has been linked in the pathogenesis of age-related macular degeneration (AMD). UVB irradiation-mediated degeneration of the macular retinal pigment epithelial (RPE) cells is an important hallmark of AMD, which is along with the change in RPE autophagy. Thus, pharmacological manipulation of RPE autophagy may offer an alternative therapeutic target in AMD. Here, we found that epigallocatechin-3-gallate (EGCG), a polyphenolic compound from green tea, plays a regulatory role in UVB irradiation-induced autophagy in RPE cells. UVB irradiation results in a marked increase in the amount of LC3-II protein in a dose-dependent manner. EGCG administration leads to a significant reduction in the formation of LC3-II and autophagosomes. mTOR signaling activation is required for EGCG-induced LC3-II formation, as evidenced by the fact that EGCG-induced LC3-II formation is significantly impaired by rapamycin administration. Moreover, EGCG significantly alleviates the toxic effects of UVB irradiation on RPE cells in an autophagy-dependent manner. Collectively, our study reveals a novel role of EGCG in RPE autophagy. EGCG may be exploited as a potential therapeutic reagent for the treatment of pathological conditions associated with abnormal autophagy

Chafuroside B, an Oolong tea polyphenol, ameliorates UVB-induced DNA damage and generation of photo-immunosuppression related mediators in human keratinocytes.

Directory of Open Access Journals (Sweden)

Tatsuya Hasegawa

Full Text Available Chafuroside B was recently isolated as a new polyphenolic constituent of oolong tea leaves. However, the effects of chafuroside B on skin function have not been examined. In this study, we investigated the protective effects of chafuroside B against UVB-induced DNA damage, apoptosis and generation of photo-immunosuppression related mediators in cultured normal human epidermal keratinocytes (NHEK. Chafuroside B at 1 µM attenuated both UVB-induced apoptosis, evaluated in terms of caspase-3/7 activity, and UVB-induced DNA damage, evaluated in terms of formation of cyclobutane pyrimidine dimers (CPD, in NHEK exposed to UVB (20 mJ/cm2. In addition, chafuroside B at 0.3 or 1 µM suppressed the UVB-induced production of interleukin (IL-10, tumor necrosis factor (TNF-α, and prostaglandin E2 (PGE2, as determined by ELISA, and conversely enhanced IL-12 mRNA expression and production, as measured by RT-PCR and ELISA. Further, chafuroside B at 1 µM also suppressed UVB-induced expression of receptor activator of nuclear factor κB ligand (RANKL mRNA. These results indicate that chafuroside B promotes repair of UVB-induced DNA damage and ameliorates the generation of IL-10, TNF-α, PGE2, and RANKL, all of which are UVB-induced immunosuppression related mediators. These effects of chafuroside B may be mediated at least in part through induction of IL-12 synthesis in human keratinocytes. Because chafuroside B might have practical value as a photoprotective agent, a further study of the in vivo effects of chafuroside B seems warranted.

Epigallocatechin-gallate (EGCG) regulates autophagy in human retinal pigment epithelial cells: A potential role for reducing UVB light-induced retinal damage

Energy Technology Data Exchange (ETDEWEB)

Li, Chao-Peng; Yao, Jin; Tao, Zhi-Fu; Li, Xiu-Miao; Jiang, Qin, E-mail: jqin710@vip.sina.com; Yan, Biao, E-mail: yanbiao1982@hotmail.com

2013-09-06

Highlights: •UVB irradiation induces RPE autophagy. •EGCG treatment represses UVB-mediated autophagy. •EGCG regulates UVB-mediated autophagy through mTOR signaling pathway. •EGCG sensitizes RPE cells to UVB-induced damage in an autophagy-dependent manner. -- Abstract: Autophagy is an intracellular catabolic process involved in protein and organelle degradation via the lysosomal pathway that has been linked in the pathogenesis of age-related macular degeneration (AMD). UVB irradiation-mediated degeneration of the macular retinal pigment epithelial (RPE) cells is an important hallmark of AMD, which is along with the change in RPE autophagy. Thus, pharmacological manipulation of RPE autophagy may offer an alternative therapeutic target in AMD. Here, we found that epigallocatechin-3-gallate (EGCG), a polyphenolic compound from green tea, plays a regulatory role in UVB irradiation-induced autophagy in RPE cells. UVB irradiation results in a marked increase in the amount of LC3-II protein in a dose-dependent manner. EGCG administration leads to a significant reduction in the formation of LC3-II and autophagosomes. mTOR signaling activation is required for EGCG-induced LC3-II formation, as evidenced by the fact that EGCG-induced LC3-II formation is significantly impaired by rapamycin administration. Moreover, EGCG significantly alleviates the toxic effects of UVB irradiation on RPE cells in an autophagy-dependent manner. Collectively, our study reveals a novel role of EGCG in RPE autophagy. EGCG may be exploited as a potential therapeutic reagent for the treatment of pathological conditions associated with abnormal autophagy.

Response to UVB radiation and oxidative stress of marine bacteria isolated from South Pacific Ocean and Mediterranean Sea.

Science.gov (United States)

Matallana-Surget, S; Villette, C; Intertaglia, L; Joux, F; Bourrain, M; Lebaron, P

2012-12-05

Marine bacterial strains isolated from South Pacific and Mediterranean Sea were studied for their resistance to UVB radiation, their repair capacity under photoreactivating light, as well as their oxidative stress response using concentrated hydrogen peroxide (H(2)O(2)), as an oxidizer. A total of 30 marine bacteria were isolated from the hyper-oligotrophic waters of the South Pacific Gyre to the eutrophic waters of the Chilean coast during the BIOSOPE cruise (2004), and 10 strains from surface Mediterranean coastal waters. One third of bacteria presented a high resistance to UVB and almost all isolates presented an efficient post-irradiation recovery. Only few strains showed cell survival to high concentration of H(2)O(2). No correlation between the sampling sites and the bacterial UVB resistance was observed. Two marine bacteria, Erythrobacter flavus and Ruegeria mobilis, were of particular interest, presenting a good response to the three parameters (UVB and H(2)O(2) resistance/efficient repair). Unexpectedly, two resistant strains were again identified as Ruegeria species underlining that this geographically widespread genus, resist to UVB regardless the environment from which the isolates originate. Copyright © 2012 Elsevier B.V. All rights reserved.

Response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings exposed to UV-B.

Science.gov (United States)

Chen, Yi-Ping

2009-07-01

To determine the response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings, Isatis indigotica seedlings were subjected to UV-B radiation (10.08 kJ m(-2)) for 8 h day(-1) for 8 days (PAR, 220 micromol m(-2) s(-1)) and then exposed to He-Ne laser radiation (633 nm; 5.23 mW mm(-2); beam diameter: 1.5 mm) for 5 min each day without ambient light radiation. Changes in free radical elimination systems were measured, the results indicate that: (1) UV-B radiation enhanced the concentration of Malondialdahyde (MDA) and decreased the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in seedlings compared with the control. The concentration of MDA was decreased and the activities of SOD, CAT and POD were increased when seedlings were subjected to elevated UV-B damage followed by laser; (2) the concentration of UV absorbing compounds and proline were increased progressively with UV-B irradiation, laser irradiation and He-Ne laser irradiation plus UV-B irradiation compared with the control. These results suggest that laser radiation has an active function in repairing UV-B-induced lesions in seedlings.

Photoprotection of Buddleja cordata extract against UVB-induced skin damage in SKH-1 hairless mice.

Science.gov (United States)

Avila Acevedo, José Guillermo; Espinosa González, Adriana Montserrat; De Maria y Campos, Diana Matamoros; Benitez Flores, José del Carmen; Hernández Delgado, Tzasna; Flores Maya, Saul; Campos Contreras, Jorge; Muñoz López, José Luis; García Bores, Ana María

2014-08-03

In recent years, there has been considerable interest in using botanical agents to prevent skin damage resulting from solar UV-irradiation. Buddleja cordata is a plant that is known as "tepozan". Some people in Mexico use the leaves of this plant to treat tumours, abscesses, sores and burns. The purpose of this study is to investigate the photoprotective properties of Buddleja cordata methanolic extract (BCME) against UVB-induced skin damage in SKH-1 hairless mice at the macroscopic and histological levels. BCME was characterised to determine its spectroscopic, chromatographic and antioxidant (DPPH, superoxide and hydroxyl radicals) properties. To conduct the photoprotection studies, BCME was applied topically to the skin of SKH-1 mice before acute exposure to UVB for 10 minutes. The murine skin samples were used for macroscopic and histological studies to assess tissue damage. Penetration of active components of BCME into stratum corneum on the dorsal area of mice was investigated in vivo by the tape stripping method. Moreover, genotoxicity of BCME was evaluated in a Vicia faba cell root micronucleus model. BCME displayed absorbance over the entire UVB spectrum, and its principal components included verbascoside and linarin. BCME exhibited antioxidant activity and significantly scavenged hydroxyl radicals. BCME reduced erythema, sunburn cell production, vessel congestion and epidermal thickening of UVB irradiated mouse skin. BCME penetrate the skin of mice. BCME did not exhibit genotoxic activity in the micronucleus test. The topical administration of BCME protected against acute UVB-induced damage in mouse SKH-1 skin, and our results suggest that BCME may potentially prevent photodamage.

A comparison of UVb compact lamps in enabling cutaneous vitamin D synthesis in growing bearded dragons.

Science.gov (United States)

Diehl, J J E; Baines, F M; Heijboer, A C; van Leeuwen, J P; Kik, M; Hendriks, W H; Oonincx, D G A B

2018-02-01

The effect of exposure to different UVb compact lamps on the vitamin D status of growing bearded dragons (Pogona vitticeps) was studied. Forty-two newly hatched bearded dragons (dragons to provide a reference level. Only one treatment resulted in elevated levels of 25(OH)D 3 compared to the control group (41.0 ± 12.85 vs. 2.0 ± 0.0 nmol/L). All UVb-exposed groups had low 25(OH)D 3 plasma levels compared to earlier studies on captive bearded dragons as well as in comparison with the free-living adult bearded dragons (409 ± 56 nmol/L). Spectral analysis indicated that all treatment lamps emitted UVb wavelengths effective for some cutaneous vitamin D synthesis. None of these lamps, under this regime, appeared to have provided a sufficient UVb dose to enable synthesis of plasma 25(OH)D 3 levels similar to those of free-living bearded dragons in their native habitat. © 2017 The Authors. Journal of Animal Physiology and Animal Nutrition Published by Blackwell Verlag GmbH.

Egg hatching response to a range of ultraviolet-B (UV-B) radiation doses for four predatory mites and the herbivorous spider mite Tetranychus urticae.

Science.gov (United States)

Koveos, Dimitrios S; Suzuki, Takeshi; Terzidou, Anastasia; Kokkari, Anastasia; Floros, George; Damos, Petros; Kouloussis, Nikos A

2017-01-01

Egg hatchability of four predatory mites-Phytoseiulus persimilis Athias-Henriot, Iphiseius [Amblyseius] degenerans Berlese, Amblyseius swirskii Athias-Henriot, and Euseius finlandicus Oudemans (Acari: Phytoseiidae)-and the spider mite Tetranychus urticae Koch (Acari: Tetranychidae) was determined under various UV-B doses either in constant darkness (DD) or with simultaneous irradiation using white light. Under UV-B irradiation and DD or simultaneous irradiation with white light, the predator's eggs hatched in significantly lower percentages than in the control non-exposed eggs, which indicates deleterious effects of UV-B on embryonic development. In addition, higher hatchability percentages were observed under UV-B irradiation and DD in eggs of the predatory mites than in eggs of T. urticae. This might be caused by a higher involvement of an antioxidant system, shield effects by pigments or a mere shorter duration of embryonic development in predatory mites than in T. urticae, thus avoiding accumulative effects of UV-B. Although no eggs of T. urticae hatched under UV-B irradiation and DD, variable hatchability percentages were observed under simultaneous irradiation with white light, which suggests the involvement of a photoreactivation system that reduces UV-B damages. Under the same doses with simultaneous irradiation with white light, eggs of T. urticae displayed higher photoreactivation and were more tolerant to UV-B than eggs of the predatory mites. Among predators variation regarding the tolerance to UV-B effects was observed, with eggs of P. persimilis and I. degenerans being more tolerant to UV-B radiation than eggs of A. swirskii and E. finlandicus.

Does imiquimod pretreatment optimize 308-nm excimer laser (UVB) therapy in psoriasis patients?

Science.gov (United States)

Tacastacas, Joselin D; Oyetakin-White, Patricia; Soler, David C; Young, Andrew; Groft, Sarah; Honda, Kord; Cooper, Kevin D; McCormick, Thomas S

2017-07-01

Psoriasis continues to be a debilitating skin disease affecting 1-3% of the United States population. Although the effectiveness of several current biologic therapies have described this pathology as a IL-23, TNF-a and Th17-mediated disease, less invasive approaches are still in use and in need of refinement. One of these is the usage of narrow band-UVB (NB-UVB) therapy to deplete specifically intra-epidermal CD3+, CD4+ and CD8+ cells to clear psoriatic plaques. In order to improve NB-UVB therapy, we sought to determine whether skin pre-treatment with the TLR7 agonist imiquimod (IMQ) would help increase the efficiency of the former at resolving psoriatic plaques. Eucerin ® Original Moisturizing Lotion (topical vehicle) or Aldara ® (imiquimod 5% topical cream) were applied for 5 days once daily to a maximum contiguous area of 25 cm 2 (5 cm × 5 cm area). Patients were provided with sachets containing 12.5 mg of imiquimod each and were instructed to apply imiquimod (I) to two psoriasis plaques (5 sachets of imiquimod allotted to each plaque). A PHAROS excimer Laser EX-308 (Ra Medical Systems, Inc. Carlsbad, CA, USA) with an output of monochromatic 308-nm light and pulse width of 20-50 ns was used for all patients. Punch biopsies of psoriatic lesions (6 mm) were taken at 4 and 48 h after final application of topical treatment with or without excimer laser treatment. Real-time quantitative RT-PCR was performed according to manufacturer's instructions and Inmunohistochemistry was used as described before. Our results suggests that although IMQ seemed to activate the type I interferon pathway as previously described, its concomitant usage with NB-UVB for clearing psoriatic skin was ineffective. Although upregulation of genes MxA, GRAMD1A and DMXL2 suggested that IMQ treatment did induce skin changes in psoriasis patients, more optimal dosing of IMQ and NB-UVB might be necessary to achieve desired treatment responses. The observation that psoriasis involvement was not

Nitric oxide-releasing sulindac is a novel skin cancer chemopreventive agent for UVB-induced photocarcinogenesis

Energy Technology Data Exchange (ETDEWEB)

Chaudhary, Sandeep C.; Singh, Tripti; Kapur, Puneet; Weng, Zhiping; Arumugam, Aadithya; Elmets, Craig A. [Department of Dermatology, University of Alabama at Birmingham, 1530 3rd Avenue South, VH509, Birmingham, AL 35294-0019 (United States); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd, Suite 2114, Bethesda, MD 20892 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology, University of Alabama at Birmingham, 1530 3rd Avenue South, VH509, Birmingham, AL 35294-0019 (United States)

2013-05-01

Nitric oxide (NO)-releasing non-steroidal anti-inflammatory drugs (NO-NSAIDs) which have been synthesized to reduce gastro-intestinal and cardiovascular toxicities of NSAIDs, possess anti-proliferative, pro-apoptotic and anti-cancer activities. Here, we show that NO-sulindac inhibited UVB-induced skin tumorigenesis in SKH-1 hairless mice. Topical application of NO-sulindac reduced tumor incidence, number (p < 0.05) and volume (p < 0.005) as compared to UVB (alone)-irradiated vehicle-treated mice. An increase in TUNEL-positive cells in skin lesions was accompanied by the enhanced Bax:Bcl-2 ratio. The expression of pro-apoptotic Bax was increased whereas anti-apoptotic Bcl-2 reduced. However, proliferation was identified as the major target of NO-sulindac in this study. A reduced expression of PCNA and cyclin D1 associated with the dampening of cell cycle progression was observed. The mechanism of this inhibition was related to the reduction in UVB-induced Notch signaling pathway. UVB-induced inflammatory responses were diminished by NO-sulindac as observed by a remarkable reduction in the levels of phosphorylated MAP Kinases Erk1/2, p38 and JNK1/2. In this regard, NO-sulindac also inhibited NFκB by enhancing IκBα as evidenced by the reduced expression of iNOS and COX-2, the direct NFκB transcription target proteins. NO-sulindac significantly diminished the progression of benign lesions to invasive carcinomas by suppressing the tumor aggressiveness and retarding epithelial–mesenchymal transition. A marked decrease in the expression of mesenchymal markers such as Fibronectin, N-cadherin, SNAI, Slug and Twist and an increase in epithelial cell polarity marker E-cadherin were noted in NO-sulindac-treated tumors. Our data suggest that NO-sulindac is a potent inhibitor of UVB-induced skin carcinogenesis and acts by targeting proliferation-regulatory pathways. - Highlights: ► NO-sulindac is a potent chemopreventive agent for UVB-induced skin cancer. ► NO

Stimulatory effect of oral administration of tea, coffee or caffeine on UVB-induced apoptosis in the epidermis of SKH-1 mice

International Nuclear Information System (INIS)

Conney, Allan H.; Zhou, Sherry; Lee Maojung; Xie Jianguo; Yang, Chung S.; Lou Yourong; Lu Yaoping

2007-01-01

Oral administration of green tea or a caffeine solution, but not decaffeinated green tea, inhibits UVB-induced complete carcinogenesis in SKH-1 mice. Oral administration of green tea, coffee or a caffeine solution for 2 weeks enhanced UVB-induced increases in apoptosis in the epidermis, but these treatments had no effect in non-UVB treated normal epidermis. Our results suggest that administration of green tea, coffee and caffeine may inhibit UVB-induced carcinogenesis - at least in part - by enhancing UVB-induced apoptosis. Plasma levels of caffeine observed after its oral administration at cancer-preventive dose levels were within the range observed in moderate coffee drinkers. Topical applications of caffeine to mice previously treated with UVB for 20 weeks (high risk mice without tumors) inhibited the formation of tumors and stimulated apoptosis in the tumors but not in areas of the epidermis away from tumors. The selective effects of caffeine administration to stimulate UVB-induced apoptosis or apoptosis in tumors but not in normal epidermis or in areas of the epidermis away from tumors is of considerable interest, but the reasons for the selective effects of caffeine on apoptosis in DNA damaged tissues are unknown. Further studies are needed to determine mechanisms of these effects of caffeine and to determine the effects of caffeine administration on sunlight-induced actinic keratoses and squamous cell carcinomas in humans

Fractionated laser resurfacing corrects the inappropriate UVB response in geriatric skin.

Science.gov (United States)

Spandau, Dan F; Lewis, Davina A; Somani, Ally-Khan; Travers, Jeffrey B

2012-06-01

Non-melanoma skin cancer is a disease primarily afflicting geriatric patients as evidenced by the fact that 80% of all non-melanoma skin cancers are diagnosed in patients over the age of 60 years. As such, geriatric skin responds to cancer-inducing UVB irradiation in a manner that allows the establishment of tumor cells. Currently, the only effective treatment for non-melanoma skin cancer is the removal of the tumors after they appear, indicating the need for a more cost-effective prophylactic therapy. Geriatric volunteers were treated with fractionated laser resurfacing therapy on either sun-protected (upper buttocks) or chronically sun-exposed (dorsal forearm) skin. Fractionated laser resurfacing therapy was shown to decrease the occurrence of senescent fibroblasts in geriatric dermis, increase the dermal expression of IGF-1, and correct the inappropriate UVB response observed in untreated geriatric skin. These responses to fractionated laser resurfacing were equal to the effects seen previously using the more aggressive wounding following dermabrasion. Furthermore, fractionated laser resurfacing was equally effective in both sun-protected and sun-exposed skin. The ability of fractionated laser resurfacing treatment to protect against the occurrence of UVB-damaged proliferating keratinocytes indicates the potential of fractionated laser resurfacing to reduce or prevent aging-associated non-melanoma skin cancer.

Effects of low or high doses of short wavelength ultraviolet light (UVB) on Langerhans cells and skin allograft survival

International Nuclear Information System (INIS)

Odling, K.A.; Halliday, G.M.; Muller, H.K.

1987-01-01

Donor C57BL mouse shaved dorsal trunk or tail skin was exposed to high (200 mJ/cm 2 ) or low (40 mJ/cm 2 ) doses of short wavelength ultraviolet light (UVB) before grafting on to the thorax of BALB/c mouse recipients of the same sex. Skin grafted 1-14 days following a single high dose of UVB irradiation was ultrastructurally depleted of LC and survived significantly longer than unirradiated skin before being rejected. After a 21-day interval between exposure and grafting when LC were again present in the epidermis there was no significant difference between treated and control graft survival. Exposure to low dose UVB irradiation only significantly increased graft survival for skin transplanted 1-3 days after irradiation; skin grafted 4 days following irradiation survived for a similar period to unirradiated control skin grafts. Electronmicroscopy showed that the low UVB dose did not deplete LC from the epidermis. We conclude that after low dose UVB treatment the class II MHC antigens on the LC Plasma membrane were lost temporarily, thus prolonging graft survival, but when the plasma membrane antigens were re-expressed graft survival returned to normal. In contrast, high-dose UVB irradiation prolonged graft survival by depleting LC from the epidermis, with graft survival only returning to control values as LC repopulated the epidermis

UVB and its global variability

International Nuclear Information System (INIS)

McKenzie, R.L.

1993-01-01

Because of geographic differences in ozone distributions and the noncircular orbit of the earth about the sun, the biologically damaging UV is at least 10-15% greater at Southern mid-latitudes than at Northern mid-latitudes. Model calculations show that at mid latitudes, biologically damaging UV should have increased 5-10% from the depletions in global ozone in the 1980s. UVB levels experienced in New Zealand are 1.5 times greater than those at compared latitudes in Europe. The larger than expected difference is due mainly to a build up of tropospheric ozone in Europe (author). 8 refs., 1 fig

The effect of cold stress on UVB injury in mouse skin and cultured keratinocytes

International Nuclear Information System (INIS)

Ota, Toshiaki; Hanada, Katsumi; Hashimoto, Isao

1996-01-01

The effect of cold stress on skin damage caused by UVB irradiation was investigated both in vivo and in vitro. Ear skin of mice that had been exposed to cold stress at 0 o C for 20 min and at 5 o C for 24 h was exposed to UVB radiation. Sunburn cell production was less in mice exposed to the lower temperature. In addition, the effect of cold stress on the survival rate of UVB-irradiated rat keratinocytes was examined in a cytoxicity test, with the results showing that keratinocytes exposed to cold stress of 0 o C had a higher survival rate than control cells. To pursue a promising clue for explaining the result, we examined metallothionein (MT) production in rat keratinocytes that had been exposed to cold stress at 0 o C. Microfluorometric quantification showed a positive correlation between the time course and the intensity of immunofluorescence for MT, indicating that the molecule is inducible by exposure to cold stress in our experimental system. These results suggest that epidermal cells that have been exposed to cold stress maintain a higher resistance to UV radiation than nonexposed controls in vivo and in vitro, and that MT with radical-scavenging activity might contribute, at least in part, to photoprotection against UVB-induced oxidative damage in mammalian skin. (Author)

The effect of cold stress on UVB injury in mouse skin and cultured keratinocytes

Energy Technology Data Exchange (ETDEWEB)

Ota, Toshiaki; Hanada, Katsumi; Hashimoto, Isao [Hirosaki Univ., Aomori (Japan). School of Medicine

1996-12-01

The effect of cold stress on skin damage caused by UVB irradiation was investigated both in vivo and in vitro. Ear skin of mice that had been exposed to cold stress at 0{sup o}C for 20 min and at 5{sup o}C for 24 h was exposed to UVB radiation. Sunburn cell production was less in mice exposed to the lower temperature. In addition, the effect of cold stress on the survival rate of UVB-irradiated rat keratinocytes was examined in a cytoxicity test, with the results showing that keratinocytes exposed to cold stress of 0{sup o}C had a higher survival rate than control cells. To pursue a promising clue for explaining the result, we examined metallothionein (MT) production in rat keratinocytes that had been exposed to cold stress at 0{sup o}C. Microfluorometric quantification showed a positive correlation between the time course and the intensity of immunofluorescence for MT, indicating that the molecule is inducible by exposure to cold stress in our experimental system. These results suggest that epidermal cells that have been exposed to cold stress maintain a higher resistance to UV radiation than nonexposed controls in vivo and in vitro, and that MT with radical-scavenging activity might contribute, at least in part, to photoprotection against UVB-induced oxidative damage in mammalian skin. (Author).

Ultraviolet-B (UV-B) radiation under high-temperature conditions affects growth of rice (cv. Koshihikari) after a young panicle formation stage

International Nuclear Information System (INIS)

Inaba, K.

2005-01-01

A japonica rice (cv. Koshihikari) was used to test the effects on blooming and ripening of UV-B radiation treatment combined with high temperature treatments (day/night, 35 / 30 deg C). Strong UV-B radiation (60.4 kJ/m(2) . day) slightly increased sterility. High temperatures and weak UV-B radiation (18.1 kJ/m(2) . day) applied together from two weeks before heading and from the heading day increased sterility and those applied from two weeks after heading decreased sterility. High temperature combined with strong UV-B radiation applied from two weeks before heading increased sterility and decreased the size of unhulled grain and anther length. The same treatment given from the heading stage greatly increased sterility and decreased anther length and pollen production, and that given two weeks after heading decreased unhulled grain weight. It also decreased photosynthetic rate in Flag leaves. A high temperature applied together with strong UV-B radiation had a synergistic effect causing poor growth; it increased the harmful effects of a high temperature and strong UV-B given separately, on the sterility and pollen formation

UV-B inhibition of hypocotyl growth in etiolated Arabidopsis thaliana seedlings is a consequence of cell cycle arrest initiated by photodimer accumulation

Science.gov (United States)

Biever, Jessica J.; Brinkman, Doug; Gardner, Gary

2014-01-01

Ultraviolet (UV) radiation is an important constituent of sunlight that determines plant morphology and growth. It induces photomorphogenic responses but also causes damage to DNA. Arabidopsis mutants of the endonucleases that function in nucleotide excision repair, xpf-3 and uvr1-1, showed hypersensitivity to UV-B (280–320nm) in terms of inhibition of hypocotyl growth. SOG1 is a transcription factor that functions in the DNA damage signalling response after γ-irradiation. xpf mutants that carry the sog1-1 mutation showed hypocotyl growth inhibition after UV-B irradiation similar to the wild type. A DNA replication inhibitor, hydroxyurea (HU), also inhibited hypocotyl growth in etiolated seedlings, but xpf-3 was not hypersensitive to HU. UV-B irradiation induced accumulation of the G2/M-specific cell cycle reporter construct CYCB1;1-GUS in wild-type Arabidopsis seedlings that was consistent with the expected accumulation of photodimers and coincided with the time course of hypocotyl growth inhibition after UV-B treatment. Etiolated mutants of UVR8, a recently described UV-B photoreceptor gene, irradiated with UV-B showed inhibition of hypocotyl growth that was not different from that of the wild type, but they lacked UV-B-specific expression of chalcone synthase (CHS), as expected from previous reports. CHS expression after UV-B irradiation was not different in xpf-3 compared with the wild type, nor was it altered after HU treatment. These results suggest that hypocotyl growth inhibition by UV-B light in etiolated Arabidopsis seedlings, a photomorphogenic response, is dictated by signals originating from UV-B absorption by DNA that lead to cell cycle arrest. This process occurs distinct from UVR8 and its signalling pathway responsible for CHS induction. PMID:24591052

UVB pretreatment of rat bone marrow allografts. Prevention of GVHD and induction of allochimerism and donor-specific unresponsiveness

International Nuclear Information System (INIS)

Chabot, J.A.; Pepino, P.; Wasfie, T.; Stegall, M.D.; Marboe, C.; Hardy, M.A.

1990-01-01

Ultraviolet B irradiation has been used to pretreat blood and islets to prevent subsequent graft rejection. In this study the optimal dose of UVB irradiation of bone marrow was determined in syngeneic recipients and was subsequently applied to in-vitro treatment of bone marrow allografts. UVB pretreatment of donor bone marrow inoculum led to complete prevention of GVHD in allogeneic rat recipients without major marrow or other toxicity. Long-standing recipients of allogeneic UVB-BM became stable adult chimeras. The recipients of allogeneic BM were populated by donor-type peripheral blood lymphocytes and did not reject host or donor-type heart grafts. The BM allograft recipients were immunocompetent as measured by their ability to normally reject third-party cardiac allografts. We suggest that the prevention of GVHD and induction of stable chimerism in adult recipients of allogeneic UVB-BM may be mediated by suppressor mechanisms

UVB pretreatment of rat bone marrow allografts. Prevention of GVHD and induction of allochimerism and donor-specific unresponsiveness

Energy Technology Data Exchange (ETDEWEB)

Chabot, J.A.; Pepino, P.; Wasfie, T.; Stegall, M.D.; Marboe, C.; Hardy, M.A. (Columbia Univ. College of Physicians and Surgeons, New York, NY (USA))

1990-05-01

Ultraviolet B irradiation has been used to pretreat blood and islets to prevent subsequent graft rejection. In this study the optimal dose of UVB irradiation of bone marrow was determined in syngeneic recipients and was subsequently applied to in-vitro treatment of bone marrow allografts. UVB pretreatment of donor bone marrow inoculum led to complete prevention of GVHD in allogeneic rat recipients without major marrow or other toxicity. Long-standing recipients of allogeneic UVB-BM became stable adult chimeras. The recipients of allogeneic BM were populated by donor-type peripheral blood lymphocytes and did not reject host or donor-type heart grafts. The BM allograft recipients were immunocompetent as measured by their ability to normally reject third-party cardiac allografts. We suggest that the prevention of GVHD and induction of stable chimerism in adult recipients of allogeneic UVB-BM may be mediated by suppressor mechanisms.

Oral administration of Aloe vera gel powder prevents UVB-induced decrease in skin elasticity via suppression of overexpression of MMPs in hairless mice.

Science.gov (United States)

Saito, Marie; Tanaka, Miyuki; Misawa, Eriko; Yao, Ruiquing; Nabeshima, Kazumi; Yamauchi, Kouji; Abe, Fumiaki; Yamamoto, Yuki; Furukawa, Fukumi

2016-07-01

This study reports the effects of oral Aloe vera gel powder (AVGP) containing Aloe sterols on skin elasticity and the extracellular matrix in ultraviolet B (UVB)-irradiated hairless mice. Ten-week-old hairless mice were fed diets containing 0.3% AVGP for 8 weeks and irradiated UVB for 6 weeks. Mice treated with AVGP showed significant prevention of the UVB-induced decrease in skin elasticity. To investigate the mechanism underlying this suppression of skin elasticity loss, we measured the expression of matrix metalloproteinase (MMP)-2, -9, and -13. AVGP prevented both the UVB-induced increases in MMPs expressions. Moreover, we investigated hyaluronic acid (HA) content of mice dorsal skin and gene expression of HA synthase-2 (Has2). In the results, AVGP oral administration prevented UVB-induced decreasing in skin HA content and Has2 expression and attenuates the UVB-induced decrease in serum adiponectin, which promotes Has2 expression. These results suggested that AVGP has the ability to prevent the skin photoaging.

Effects of enhanced UVB on growth and yield of two Syrian crops; wheat (Triticum durum desf. var. Horani) and broad beans field conditions

International Nuclear Information System (INIS)

Al-Oudat, M.; Baydoun, S.A.; Mohammed, A.

1998-01-01

Wheat and broad beans were exposed, under field conditions, to a daily UVB of 20 % above the ambient UVB. The plant height, tiller number, number of flowers, spikletes, dry weight and leaf area in both species showed positive responses to UVB treatment. At harvest, the seeds weight of broad beans was virtually equal in exposed and unexposed plants. In wheat, seeds yield increased significantly by 15 %. In conclusion, broad beans can be considered as a tolerant cultivar to enhanced UVB, while wheat is more tolerant. (Author)

Effect of UV-B and high visual radiation on photosynthesis in freshwater (nostoc spongiaeforme) and marine (Phormidium corium) cyanobacteria.

Science.gov (United States)

Bhandari, Rupali; Sharma, Prabhat Kumar

2007-08-01

Human activity is causing depletion of ozone in stratosphere, resulting in increased UV-B radiation and global warming. However, impact of these climatic changes on the aquatic organism (especially marine) is not fully understood. Here, we have studied the effect of excess UV-B and visible radiation on photosynthetic pigments, fatty acids content, lipid peroxidation, nitrogen content, nitrogen reductase activity and membrane proteins, induction of mycosporine-like amino acids (MAAs) and antioxidant enzymes superoxide dismutase (SOD) and ascorbate peroxidase (APX) in freshwater (Nostoc spongiaeform) and marine (Phormidium corium) cyanobacteria. UV-B treatment resulted in an increase in photosynthetic pigments in Nostoc and decrease in Phormidium, but high light treatment caused photobleaching of most of the pigments in both the species. Unsaturation level of fatty acids of both total and glycolipids remained unchanged in both the cyanobacteria, as a result of UV-B and high light treatments. Saturated fatty acids of total and glycolipids declined slightly in Nostoc by both the treatments. but remained unchanged in Phormidium. No changes in the unsaturated lipid content in our study probably suggested adaptation of the organism to the treatments. However, both treatments resulted in peroxidation of membrane lipids, indicating oxidative damage to lipids without any change in the level of unsaturation of fatty acid in the cell membrane. Qualitative and quantitative changes were observed in membrane protein profile due to the treatments. Cyanobacteria were able to synthesize MAAs in response to the UV-B treatment. Both treatments also increased the activities of SOD and APX. In conclusion, the study demonstrated induction of antioxidants such as SOD and APX under visible light treatment and screening pigment (MAAs) under UV-B treatment, which might protect the cyanobacteria from oxidative damage caused by high light and UV-B radiation.

Ultraviolet-B (UV-B) radiation as an elicitor of flavonoid production in callus cultures of jatropha (Jatropha curcas L.)

International Nuclear Information System (INIS)

Alvero-Bascos, E.M.; Ungson, L.B.

2012-01-01

Callus cultures of jatropha (Jatropha curcas L.) grown in Murashige and Skoog's (MS) medium supplemented with naphthalene-acetic acid (NAA, 20 microM) and 6-furfurylaminopurine (kinetin, 20 microM) were exposed to ultraviolet-B (UV-B) radiation to investigate its potential as an abiotic elicitor of flavonoid production. Prior to irradiation, the levels of the flavonoids, apigenin, vitexin and isovitexin in the leaf and callus extracts were determined through high performance liquid chromatography (HPLC). Results showed that vitexin and isovitexin were the dominant flavonoids in the leaves while only apigenin was detected in the calli, suggesting a correlation between the degree of differentiation and biosynthesis of flavonoids in plant tissues. Irradiation of callus cultures for 7 d using two UV-B doses (12.6 and 25.3 kJ/sq m) induced synthesis of all three flavonoids (up to 780 micro g/g dw increase) to levels similar to or higher than those found in whole leaves. The combined levels of the three flavonoids in the cultures treated with the higher UV-B dose were 20-fold higher than the control and were comparable to concentrations found in leaves while a 10-fold increase in combined flavonoid levels was observed in calli irradiated with the lower UV-B dose. Furthermore, random amplified polymorphic DNA (RAPD) analyses of DNA extracts from the leaves and calli revealed that UV-B irradiation enhanced flavonoid synthesis without altering DNA sequence. These results further support the supposed involvement of UV-B in the transcriptional regulation of the expression of flavonoid biosysnthetic genes. Overall, the findings showed that elicitation through UV-B irradiation is an effective strategy to induce flavonoid production in dedifferentiated J. curcas cultures that have lost their capacity to produce the flavonoids normally synthesized in intact organs. (author)

Acclimation to UV-B radiation and visible light in Lactuca sativa involves up-regulation of photosynthetic performance and orchestration of metabolome-wide responses.

Science.gov (United States)

Wargent, J J; Nelson, B C W; McGhie, T K; Barnes, P W

2015-05-01

UV-B radiation is often viewed as a source of stress for higher plants. In particular, photosynthetic function has been described as a common target for UV-B impairment; yet as our understanding of UV-B photomorphogenesis increases, there are opportunities to expand the emerging paradigm of regulatory UV response. Lactuca sativa is an important dietary crop species and is often subjected to rapid sunlight exposure at field transfer. Acclimation to UV-B and visible light conditions in L. sativa was dissected using gas exchange and chlorophyll fluorescence measurements, in addition to non-destructive assessments of UV epidermal shielding (SUV ). After UV-B treatment, seedlings were subjected to wide-range metabolomic analysis using liquid chromatography hybrid quadrupole time-of-flight high-resolution mass spectrometry (LC-QTOF-HRMS). During the acclimation period, net photosynthetic rate increased in UV-treated plants, epidermal UV shielding increased in both subsets of plants transferred to the acclimatory conditions (UV+/UV- plants) and Fv /Fm declined slightly in UV+/UV- plants. Metabolomic analysis revealed that a key group of secondary compounds was up-regulated by higher light conditions, yet several of these compounds were elevated further by UV-B radiation. In conclusion, acclimation to UV-B radiation involves co-protection from the effects of visible light, and responses to UV-B radiation at a photosynthetic level may not be consistently viewed as damaging to plant development. © 2014 John Wiley & Sons Ltd.

Combination of U.V.-B and ozone reduces pollen tube growth more than either stress alone

International Nuclear Information System (INIS)

Feder, W.A.; Shrier, R.

1990-01-01

The rate of in vitro Nicotiana tabacum L. “Bel-W3” pollen tube growth was reduced 62 and 44%, respectively, when pollen tubes were exposed to 120 ppb ozone (O 3 ) for 3 hr or 300 μW/cm 2 ultraviolet-B (u.v.-B) radiation for 30 min. Petunia hybrida Vilm. “White Cascade” pollen tube growth was reduced 34 and 59%, respectively, upon exposure to O 3 or u.v.-B at the above doses. The combination of u.v.-B at 300 μW/cm 2 for 30 min, followed by O 3 at 120 ppb for 3 hr, reduced pollen tube growth by 79% for “Bel-W3” and 75% for “White Cascade”. The effect appeared to be additive, implying that different target areas may be affected by the two stressors. In the Northeast, plants are exposed to both u.v.-B and O 3 during the normal growing season. This may result in an unexpectedly higher stress on the reproductive system than had been previously suspected based on these two stressors acting individually. (author)

UVB radiation generates sunburn pain and affects skin by activating epidermal TRPV4 ion channels and triggering endothelin-1 signaling.

Science.gov (United States)

Moore, Carlene; Cevikbas, Ferda; Pasolli, H Amalia; Chen, Yong; Kong, Wei; Kempkes, Cordula; Parekh, Puja; Lee, Suk Hee; Kontchou, Nelly-Ange; Yeh, Iwei; Ye, Iwei; Jokerst, Nan Marie; Fuchs, Elaine; Steinhoff, Martin; Liedtke, Wolfgang B

2013-08-20

At our body surface, the epidermis absorbs UV radiation. UV overexposure leads to sunburn with tissue injury and pain. To understand how, we focus on TRPV4, a nonselective cation channel highly expressed in epithelial skin cells and known to function in sensory transduction, a property shared with other transient receptor potential channels. We show that following UVB exposure mice with induced Trpv4 deletions, specifically in keratinocytes, are less sensitive to noxious thermal and mechanical stimuli than control animals. Exploring the mechanism, we find that epidermal TRPV4 orchestrates UVB-evoked skin tissue damage and increased expression of the proalgesic/algogenic mediator endothelin-1. In culture, UVB causes a direct, TRPV4-dependent Ca(2+) response in keratinocytes. In mice, topical treatment with a TRPV4-selective inhibitor decreases UVB-evoked pain behavior, epidermal tissue damage, and endothelin-1 expression. In humans, sunburn enhances epidermal expression of TRPV4 and endothelin-1, underscoring the potential of keratinocyte-derived TRPV4 as a therapeutic target for UVB-induced sunburn, in particular pain.

Response of growth and antioxidant enzymes in Azolla plants (Azolla pinnata and Azolla filiculoides) exposed to UV-B.

Science.gov (United States)

Masood, Amjad; Zeeshan, M; Abraham, G

2008-06-01

Effect of ultravilolet-B (0.4 Wm(-2)) irradiation on growth, flavonoid content, lipid peroxidation, proline accumulation and activities of superoxide dismutase and peroxidase was comparatively analysed in Azolla pinnata and Azolla filiculoides. Growth measured as increment in dry weight reduced considerably due to all UV-B treatments. However, the reduction was found to be severe in A. filiculoides as compared to A. pinnata. The level of UV-absorbing compound flavonoids increased significantly in A. pinnata plants whereas only a slight increase in the flavonoid content was observed in A. filiculoides. UV-B exposure led to enhanced production of malondialdehyde (MDA) and electrolyte leakage in A. filiculoides than A. pinnata. Proline accumulation also showed a similar trend. Marked differences in the activity of antioxidant enzymes such as superoxide dismutase (SOD) and peroxidase (POD) was noticed in both the plants exposed to UV-B. Our comparative studies indicate A. pinnata to be better tolerant to UV-B as compared with A. filiculoides which appears to be sensitive.

UVB-Stimulated TNFα Release from Human Melanocyte and Melanoma Cells Is Mediated by p38 MAPK

Directory of Open Access Journals (Sweden)

Visalini Muthusamy

2013-08-01

Full Text Available Ultraviolet (UV radiation activates cell signaling pathways in melanocytes. As a result of altered signaling pathways and UV-induced cellular damage, melanocytes can undergo oncogenesis and develop into melanomas. In this study, we investigated the effect of UV-radiation on p38 MAPK (mitogen-activated protein kinase, JNK and NFκB pathways to determine which plays a major role in stimulating TNFα secretion in human HEM (melanocytes and MM96L (melanoma cells. MM96L cells exhibited 3.5-fold higher p38 activity than HEM cells at 5 min following UVA + B radiation and 1.6-fold higher JNK activity at 15–30 min following UVB+A radiation, while NFκB was minimally activated in both cells. Irradiated HEM cells had the greatest fold of TNFα secretion (UVB: 109-fold, UVA + B: 103-fold & UVB+A: 130-fold when co-exposed to IL1α. The p38 inhibitor, SB202190, inhibited TNFα release by 93% from UVB-irradiated HEM cells. In the UVB-irradiated MM96L cells, both SB202190 and sulfasalazine (NFκB inhibitor inhibited TNFα release by 52%. Although, anisomycin was a p38 MAPK activator, it inhibited TNFα release in UV-irradiated cells. This suggests that UV-mediated TNFα release may occur via different p38 pathway intermediates compared to those stimulated by anisomycin. As such, further studies into the functional role p38 MAPK plays in regulating TNFα release in UV-irradiated melanocyte-derived cells are warranted.

UV-B absorbing pigments in spores: biochemical responses to shade in a high-latitude birch forest and implications for sporopollenin-based proxies of past environmental change

Directory of Open Access Journals (Sweden)

Terry V. Callaghan

2011-08-01

Full Text Available Current attempts to develop a proxy for Earth's surface ultraviolet-B (UV-B flux focus on the organic chemistry of pollen and spores because their constituent biopolymer, sporopollenin, contains UV-B absorbing pigments whose relative abundance may respond to the ambient UV-B flux. Fourier transform infrared (FTIR microspectroscopy provides a useful tool for rapidly determining the pigment content of spores. In this paper, we use FTIR to detect a chemical response of spore wall UV-B absorbing pigments that correspond with levels of shade beneath the canopy of a high-latitude Swedish birch forest. A 27% reduction in UV-B flux beneath the canopy leads to a significant (p<0.05 7.3% reduction in concentration of UV-B absorbing compounds in sporopollenin. The field data from this natural flux gradient in UV-B further support our earlier work on sporopollenin-based proxies derived from sedimentary records and herbaria collections.

Effects of UVB-induced oxidative stress on protein expression and specific protein oxidation in normal human epithelial keratinocytes: a proteomic approach

Directory of Open Access Journals (Sweden)

De Marco Federico

2010-03-01

Full Text Available Abstract Background The UVB component of solar ultraviolet irradiation is one of the major risk factors for the development of skin cancer in humans. UVB exposure elicits an increased generation of reactive oxygen species (ROS, which are responsible for oxidative damage to proteins, DNA, RNA and lipids. In order to examine the biological impact of UVB irradiation on skin cells, we used a parallel proteomics approach to analyze the protein expression profile and to identify oxidatively modified proteins in normal human epithelial keratinocytes. Results The expression levels of fifteen proteins - involved in maintaining the cytoskeleton integrity, removal of damaged proteins and heat shock response - were differentially regulated in UVB-exposed cells, indicating that an appropriate response is developed in order to counteract/neutralize the toxic effects of UVB-raised ROS. On the other side, the redox proteomics approach revealed that seven proteins - involved in cellular adhesion, cell-cell interaction and protein folding - were selectively oxidized. Conclusions Despite a wide and well orchestrated cellular response, a relevant oxidation of specific proteins concomitantly occurs in UVB-irradiated human epithelial Keratinocytes. These modified (i.e. likely dysfunctional proteins might result in cell homeostasis impairment and therefore eventually promote cellular degeneration, senescence or carcinogenesis.

Epidermal transmittance and phenolic composition in leaves of atrazine-tolerant and atrazine-sensitive cultivars of Brassica napus grown under enhanced UV-B radiation

International Nuclear Information System (INIS)

Olsson, L.C.; Veit, M.; Bornman, J.F.

1999-01-01

Experiments were conducted on the atrazine-tolerant mutant Stallion and the atrazine-sensitive cv. Paroll of Brassica napus L., which were grown under either visible light or with the addition of UV-B radiation (280–320 nm) for 15 days. The mutant has been shown to be sensitive to high levels of visible light as compared to the atrazine-sensitive cultivar and therefore we wished to determine plant response to UV-B radiation with respect to potential pigment changes, certain anatomical features, radiation penetration and partial photosynthesis. With regard to pigment changes, we were particularly interested in whether the compositional shift in flavonol pigments under enhanced UV-B radiation, previously suggested to favour increased antioxidant activity, is confined to the adaxial epidermis, which generally receives most UV-B radiation or whether the pigment shift is also inducible in the abaxial epidermis.As was to be expected, the penetration of UV-B radiation (310 nm) was lower in the UV-B-exposed plants, which was correlated with an increased amount of UV-screening pigments in the adaxial and abaxial epidermal layers. The main flavonoid glycosides showed the largest shift from kaempferol to quercetin as aglycone moiety in the adaxial epidermal layer. However, in the abaxial epidermal layer the hydroxycinnamic acid (HCA) derivatives and kaempferol glycosides were predominant. Penetration of 430 nm light was higher after UV-B exposure, and probably contributed to the fact that photosynthetic efficiency of photosystem II was unchanged or higher after UV-B exposure. UV-B radiation decreased leaf area in the atrazine-tolerant mutant only. Both cultivars showed an increased leaf thickness after UV-B exposure due to cell elongation mainly of the palisade tissue. This was especially evident in the mutant

Qual é o tipo de fototerapia mais comumente indicada no tratamento da psoríase?: UVB banda estreita e PUVA: comportamento da prescrição What is the most common phototherapy prescription for psoriasis: NB-UVB or PUVA? Prescription behavior

Directory of Open Access Journals (Sweden)

Ida Duarte

2009-07-01

Full Text Available FUNDAMENTOS: Formas moderada e grave de psoríase requerem fototerapia e/ou medicações sistêmicas. Tanto UVB banda estreita quanto fototerapia UVA com psoralênicos (PUVA podem ser utilizadas no tratamento dessas formas de psoríase, sendo comprovada a efetividade de ambas as terapias. OBJETIVOS: Avaliar as indicações de dois tipos de fototerapia no tratamento da psoríase refratária à terapia tópica: UVB banda estreita e PUVA. MÉTODOS: Entre janeiro de 2006 e dezembro de 2007, os pacientes encaminhados a dois serviços de fototerapia foram incluídos neste estudo. Dados sobre os casos e tipos de prescrição foram coletados de maneira retrospectiva. RESULTADOS: Dentre os 67 pacientes estudados, 51 (76% foram tratados com UVB banda estreita. As razões para sua indicação foram presença de psoríase em gotas (22%, presença de finas placas (15%, uso de drogas fotossensibilizantes (15%, idade abaixo de 20 anos (9%, fototipo I (9% e doença hepática (6%. Os 16 (24% restantes foram tratados com PUVA. A principal indicação dessa terapia foi gravidade da doença (15%, seguida de fototipo IV (9%. CONCLUSÕES: As prescrições de UVB banda estreita excederam as de PUVA devido ao menor número de contraindicações, menor possibilidade de efeitos colaterais, e ainda por ser uma opção mais prática.BACKGROUND: Moderate and severe forms of psoriasis require phototherapy and / or systemic medications. Both UVA and UVB can be used to treat cases of moderate and severe psoriasis, and the effectiveness of both has been proven. OBJECTIVE: to access the prescription behavior relating to two types of phototherapy for treating psoriasis refractory to topical treatment: narrowband UVB (NB-UVB or psoralen plus UVA phototherapy (PUVA. METHODS: Between January 2006 and December 2007, patients referred to two phototherapy services were included in this study. Data on the cases and on the type of prescription were collected retrospectively. RESULTS

Differences in the Sensitivity to UVB Radiation of Two Cultivars of Rice (Oryza sativa L.)

OpenAIRE

Jun, Hidema; Hye-Sook, Kang; Tadashi, Kumagai; Institute of Genetic Ecology, Tohoku University; Institute of Genetic Ecology, Tohoku University; Institute of Genetic Ecology, Tohoku University

1996-01-01

The effects of UVB radiation on the growth of two cultivars of Japanese lowland rice (Oryza sativa L.), Sasanishiki and Norin 1, were examined in a phytotron. Supplementation of visible radiation with UVB radiation reduced plant length, tiller number, the fresh and dry weights of the aboveground parts of plants, and the amounts of total leaf nitrogen, chlorophyll, soluble protein and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the eighth leaf, the youngest fully expanded leaf...

Photo-protective effect of calcipotriol upon skin photoreaction to UVA and UVB

International Nuclear Information System (INIS)

Youn, J.I.; Park, B.S.; Chung, J.H.; Lee, J.H.

1997-01-01

It has been shown that 1,25-dihydroxyvitamin D 3 has a photo-protective effect against UVB injury in mouse skin and cultured rat keratinocytes by induction of metallothionein (MT). Calcipotriol is a synthetic analogue of 1,25-dihydroxyvitamin D 3 with equi-potent cell regulating properties, but with a lower risk of calcium-related side effects. The aim of the present study was to see whether calcipotriol has a photo-protective property both in vitro and in vivo. We examined the effect of calcipotriol on UV-induced damage of cultured human keratinocytes through a cell viability assay, and measurement of DNA synthesis by cultured keratinocytes, on UV-induced damage of mouse skin and on minimal erythema dose (MED). We found that calcipotriol was protective against UVB-induced reduction in DNA synthetic activity of cultured keratinocytes in relatively low doses (20 and 40 mJ/cm 2 ) of UVB. With photo-testing following application of calcipotriol, five subjects among 10 healthy volunteers and three among six psoriasis patients showed an increase in MED compared with the vehicle-treated site. These findings imply that calcipotriol may be photo-protective and that more extensive studies with various doses of UV irradiation and modes of calcipotriol delivery are required. (au)

Photo-protective effect of calcipotriol upon skin photoreaction to UVA and UVB

Energy Technology Data Exchange (ETDEWEB)

Youn, J.I.; Park, B.S.; Chung, J.H. [Seoul National Univ. College of Medicine, Dept. of Dermatology, Seoul (Korea, Republic of); Lee, J.H. [Inha Univ. College of Medicine, Incheon (Korea, Republic of)

1997-03-01

It has been shown that 1,25-dihydroxyvitamin D{sub 3} has a photo-protective effect against UVB injury in mouse skin and cultured rat keratinocytes by induction of metallothionein (MT). Calcipotriol is a synthetic analogue of 1,25-dihydroxyvitamin D{sub 3} with equi-potent cell regulating properties, but with a lower risk of calcium-related side effects. The aim of the present study was to see whether calcipotriol has a photo-protective property both in vitro and in vivo. We examined the effect of calcipotriol on UV-induced damage of cultured human keratinocytes through a cell viability assay, and measurement of DNA synthesis by cultured keratinocytes, on UV-induced damage of mouse skin and on minimal erythema dose (MED). We found that calcipotriol was protective against UVB-induced reduction in DNA synthetic activity of cultured keratinocytes in relatively low doses (20 and 40 mJ/cm{sup 2}) of UVB. With photo-testing following application of calcipotriol, five subjects among 10 healthy volunteers and three among six psoriasis patients showed an increase in MED compared with the vehicle-treated site. These findings imply that calcipotriol may be photo-protective and that more extensive studies with various doses of UV irradiation and modes of calcipotriol delivery are required. (au). 21 refs.

Study of Oxidative Stress in Vitiligo and Use of Narrow Band UVB-311 as a Method of Treatment

International Nuclear Information System (INIS)

Fawzy, N.; Rashed, L.

2012-01-01

Vitiligo is an acquired depigmenting disease characterized by circumscribed depigmenting macules devoid of identifiable melanocytes. The disease has uncertain aetiopathogenesis. The aim of this research is to estimate the level of superoxide dismutase (SOD) and catalase (CAT) as antioxidants and Nitric oxide and superoxide anion as oxidants in vitiligo patients and evaluate the clinical effectiveness of narrow band UVB (NB-UVB-311) as a method of treatment and repairing the oxidative stress-induced damage. This study included twenty vitiligo patients and fifteen-age and sex matched control. There was statistically significant increase in the levels of SOD in active vitiligo lesions compared to control (P<0.001). There was statistically significant decrease in the level of CAT in vitiligo skin lesions compared to skin of control. After using NB-UVB- 311 the level of SOD was significantly decreased and CAT level was significantly increased (P<0.001). There was statistically significant increase in the level of nitric oxide and superoxide in vitiligo patients compared to control. After using NB-UVB-311 as treatment, the level of nitric oxide and superoxide anion was significantly decreased (P<0.001) in vitiligo patients. These results provide some evidence regarding the oxidant /antioxidant balance in vitiligo patients and the positive role of narrow band UVB- 311 as a treatment of vitiligo

Study of the anticorrelations between ozone and UV-B radiation using linear and exponential fits in Southern Brazil

Science.gov (United States)

Guarnieri, R.; Padilha, L.; Guarnieri, F.; Echer, E.; Makita, K.; Pinheiro, D.; Schuch, A.; Boeira, L.; Schuch, N.

Ultraviolet radiation type B (UV-B 280-315nm) is well known by its damage to life on Earth, including the possibility of causing skin cancer in humans. However, the atmo- spheric ozone has absorption bands in this spectral radiation, reducing its incidence on Earth's surface. Therefore, the ozone amount is one of the parameters, besides clouds, aerosols, solar zenith angles, altitude, albedo, that determine the UV-B radia- tion intensity reaching the Earth's surface. The total ozone column, in Dobson Units, determined by TOMS spectrometer on board of a NASA satellite, and UV-B radiation measurements obtained by a UV-B radiometer model MS-210W (Eko Instruments) were correlated. The measurements were obtained at the Observatório Espacial do Sul - Instituto Nacional de Pesquisas Espaciais (OES/CRSPE/INPE-MCT) coordinates: Lat. 29.44oS, Long. 53.82oW. The correlations were made using UV-B measurements in fixed solar zenith angles and only days with clear sky were selected in a period from July 1999 to December 2001. Moreover, the mathematic behavior of correlation in dif- ferent angles was observed, and correlation coefficients were determined by linear and first order exponential fits. In both fits, high correlation coefficients values were ob- tained, and the difference between linear and exponential fit can be considered small.

Penetration of UV-A, UV-B, blue, and red light into leaf tissues of pecan measured by a fiber optic microprobe system

Science.gov (United States)

Qi, Yadong; Bai, Shuju; Vogelmann, Thomas C.; Heisler, Gordon M.

2003-11-01

The depth of light penetration from the adaxial surfaces of the mature leaves of pecan (Carya illinoensis) was measured using a fiber optic microprobe system at four wavelengths: UV-B (310nm), UV-A (360 nm), blue light (430nm), and red light (680nm). The average thickness of the leaf adaxial epidermal layer was 15um and the total leaf thickness was 219um. The patterns of the light attenuation by the leaf tissues exhibited strong wavelength dependence. The leaf adaxial epidermal layer was chiefly responsible for absorbing the UV-A UV-B radiation. About 98% of 310 nm light was steeply attenuated within the first 5 um of the adaxial epidermis; thus, very little UV-B radiation was transmitted to the mesophyll tissues where contain photosynthetically sensitive sites. The adaxial epidermis also attenuated 96% of the UV-A radiation. In contrast, the blue and red light penetrated much deeper and was gradually attenutated by the leaves. The mesophyll tissues attenuated 17% of the blue light and 42% of the red light, which were available for photosynthesis use. Since the epidermal layer absorbed nearly all UV-B light, it acted as an effective filter screening out the harmful radiation and protecting photosynthetically sensitive tissues from the UV-B damage. Therefore, the epidermal function of the UV-B screening effectiveness can be regarded as one of the UV-B protection mechanisms in pecan.

Increase of the efficiency of heat pumps by partial defrosting of evaporator during the heating operation; Effizienzsteigerung von Waermepumpen durch partielle Verdampferabtauung waehrend des Heizbetriebs

Energy Technology Data Exchange (ETDEWEB)

Mader, Gunda; Thybo, Claus [Danfoss A/S, Nordborg (Denmark)

2011-07-01

At low ambient temperatures, the evaporation temperature in air-to-water heat pumps may fall below the freezing point of water; the water content of the air will then form a frost layer on the outside of the heat exchanger. This increases the pressure drop on the air side and reduces the heat transfer capacity, i.e. the energy efficiency of the system. Finally, if operation in these conditions continues, the evaporator may freeze in parts or even wholly. In order to prevent failure and damage, regular defrosting will be necessary. One common method is the reversal of the coolant flow by leading hot gas into the evaporator from the condenser. Apart from the loss of efficiency, this will incur material problems and, in some cases, loss of comfort. Partial thawing attempts to reduce or avoid flow reversal by deactivating evaporator lines one at a time in order to enable thawing by air flow, while the other parts of the evaporator will continue operation. This is made possible by a special type of valve that combines expansion and distribution for selective operation of individual evaporator tubes. Using a mathematical model, details of the method are presented and discussed. Experiments on air-to-air heat pumps show that the whole system can be defrosted this way in standard operating conditions with air temperatures above freezing point, so that flow reversal will not be necessary. [German] Bei niedrigen Aussentemperaturen kann die Verdampfungstemperatur in Luft-Waermepumpen unter den Gefrierpunkt von Wasser fallen, der Wassergehalt der Luft bildet dann auf der Aussenseite des Waermeuebertragers eine Frostschicht. Dies fuehrt zu einem erhoehten luftseitigen Druckabfall und reduzierter Waermeuebertragungsleistung des Verdampfers und mindert folglich die Energieeffizienz des Systems. Bei andauerndem Betrieb schliesslich kann der Verdampfer gaenzlich oder in grossen Bereichen zufrieren. Um einen Ausfall oder gar eine Beschaedigung der Anlage zu verhindern, muss daher

Lens epithelial cell apoptosis is an early event in the development of UVB-induced cataract.

Science.gov (United States)

Li, W C; Spector, A

1996-01-01

Epidemiological and experimental studies have revealed that exposure to UV can induce cataractogenesis. To investigate the mechanism of this induction, viability of the lens epithelial cells from UVB-treated rat lenses were examined. Irradiation of the cultured rat lenses with 8 J/s/m2 UVB for 60 min triggers lens epithelial cell apoptosis as determined by terminal deoxyribonucleotide transferase (TdT) labeling and DNA fragmentation assays. The apoptotic lens epithelial cells were initially found in the equatorial region and then quickly appeared in both equatorial and central regions. The percentage of apoptotic cells continuously increased during the postirradiation incubation. After a 5-h post-UVB incubation, more than 50% of the lens epithelial cells were apoptotic. By 24 h, all of the lens epithelial cells in the irradiated lenses were dead through apoptosis. Associated with this apoptotic process is a large upregulation of the proto-oncogene, c-fos. Opacification appears to follow the death of lens epithelial cells occurring first in the equatorial region and then in the central area. This is also true of classical cataract parameters such as non-protein thiol and wet weight, which are significantly modified only after appreciable epithelial cell apoptosis. Together, these results suggest that the rapid apoptotic death of the lens epithelial cells induced by UVB initiates cataract development.

Vitamin D production after UVB exposure depends on baseline vitamin D and total cholesterol but not on skin pigmentation.

Science.gov (United States)

Bogh, Morten K B; Schmedes, Anne V; Philipsen, Peter A; Thieden, Elisabeth; Wulf, Hans C

2010-02-01

UVB radiation increases serum vitamin D level expressed as 25-hydroxyvitamin-D(3) (25(OH)D), but the influence of skin pigmentation, baseline 25(OH)D level, and total cholesterol has not been well characterized. To determine the importance of skin pigmentation, baseline 25(OH)D level, and total cholesterol on 25(OH)D production after UVB exposure, 182 persons were screened for 25(OH)D level. A total of 50 participants with a wide range in baseline 25(OH)D levels were selected to define the importance of baseline 25(OH)D level. Of these, 28 non-sun worshippers with limited past sun exposure were used to investigate the influence of skin pigmentation and baseline total cholesterol. The participants had 24% of their skin exposed to UVB (3 standard erythema doses) four times every second or third day. Skin pigmentation and 25(OH)D levels were measured before and after the irradiations. Total cholesterol was measured at baseline. The increase in 25(OH)D level after UVB exposure was negatively correlated with baseline 25(OH)D level (Ppigmentation. In addition, we paired a dark-skinned group with a fair-skinned group according to baseline 25(OH)D levels and found no differences in 25(OH)D increase after identical UVB exposure.

Blood vitamin D(3) metabolite concentrations of adult female bearded dragons (Pogona vitticeps) remain stable after ceasing UVb exposure.

Science.gov (United States)

Oonincx, D G A B; van de Wal, M D; Bosch, G; Stumpel, J B G; Heijboer, A C; van Leeuwen, J P T M; Hendriks, W H; Kik, M

2013-07-01

Vitamin D deficiency can lead to several health problems collectively called metabolic bone disease (MBD). One commonly kept reptile species prone to develop MBD if managed incorrectly is the bearded dragon (Pogona vitticeps). This study aimed to determine the extent to which adult female bearded dragons fed a diet low in vitamin D can use stored vitamin D and its metabolites to maintain plasma 25(OH)D(3) and 1,25(OH)(2)D(3) concentrations after discontinuing UVb exposure. Blood samples of healthy adult female bearded dragons, exposed to UVb radiation for over 6 months were collected (day 0) after which UVb exposure was discontinued for 83 days and blood was collected. Blood plasma was analysed for concentrations of total Ca, total P, ionized Ca, uric acid, 25(OH)D(3) and 1,25(OH)(2)D(3). There was no significant change in plasma 25(OH)D(3) and 1,25(OH)(2)D(3) concentrations during the study. While total Ca and P in whole blood was found to significantly decrease over time (P dragons, previously exposed to UVb, are able to maintain blood vitamin D metabolite concentrations when UVb exposure is discontinued for a period of up to 83 days. Copyright © 2013 Elsevier Inc. All rights reserved.

Above- and below-ground responses of Calamagrostis purpurea to UV-B radiation and elevated CO{sub 2} under phosphorus limitation

Energy Technology Data Exchange (ETDEWEB)

Bussell, J.S.; Gwynn-Jones, D.; Griffith, G.W.; Scullion, J. (Aberystwyth Univ., IBERS, Wales (United Kingdom))

2012-08-15

UV-B radiation and elevated CO{sub 2} may impact rhizosphere processes through altered below-ground plant resource allocation and root exudation, changes that may have implications for nutrient acquisition. As nutrients limit plant growth in many habitats, their supply may dictate plant response under elevated CO{sub 2}. This study investigated UV-B exposure and elevated CO{sub 2} effects, including interactions, on plant growth, tissue chemistry and rooting responses relating to P acquisition. The sub-arctic grass Calamagrostis purpurea was subjected to UV-B (0 or 3.04 kJ m-2day-1) and CO{sub 2} (ambient 380 or 650 ppmv) treatments in a factorial glasshouse experiment, with sparingly soluble P (0 or 0.152 mg P per plant as FePO{sub 4}) a further factor. It was hypothesized that UV-B exposure and elevated CO{sub 2} would change plant resource allocation, with CO{sub 2} mitigating adverse responses to UV-B exposure and aiding P uptake. Plant biomass and morphology, tissue composition and rhizosphere leachate properties were measured. UV-B directly affected chemical composition of shoots and interacted with CO{sub 2} to give a greater root biomass. Elevated CO{sub 2} altered the composition of both shoots and roots and increased shoot biomass and secondary root length, while leachate pH decreased. Below-ground responses to CO{sub 2} did not affect P acquisition although P limitation progressively reduced leachate pH and increased secondary root length. Although direct plant growth, foliar composition and below-ground nutrient acquisition responses were dominated by CO{sub 2} treatments, UV-B modified these CO{sub 2} responses significantly. These interactions have implications for plant responses to future atmospheric conditions. (Author)

ER signaling is activated to protect human HaCaT keratinocytes from ER stress induced by environmental doses of UVB

International Nuclear Information System (INIS)

Mera, Kentaro; Kawahara, Ko-ichi; Tada, Ko-ichi; Kawai, Kazuhiro; Hashiguchi, Teruto; Maruyama, Ikuro; Kanekura, Takuro

2010-01-01

Proteins are folded properly in the endoplasmic reticulum (ER). Various stress such as hypoxia, ischemia and starvation interfere with the ER function, causing ER stress, which is defined by the accumulation of unfolded protein (UP) in the ER. ER stress is prevented by the UP response (UPR) and ER-associated degradation (ERAD). These signaling pathways are activated by three major ER molecules, ATF6, IRE-1 and PERK. Using HaCaT cells, we investigated ER signaling in human keratinocytes irradiated by environmental doses of ultraviolet B (UVB). The expression of Ero1-Lα, an upstream signaling molecule of ER stress, decreased at 1-4 h after 10 mJ/cm 2 irradiation, indicating that the environmental dose of UVB-induced ER stress in HaCaT cells, without growth retardation. Furthermore, expression of intact ATF6 was decreased and it was translocated to the nuclei. The expression of XBP-1, a downstream molecule of IRE-1, which is an ER chaperone whose expression is regulated by XBP-1, and UP ubiquitination were induced by 10 mJ/cm 2 UVB at 4 h. PERK, which regulates apoptosis, was not phosphorylated. Our results demonstrate that UVB irradiation generates UP in HaCaT cells and that the UPR and ERAD systems are activated to protect cells from UVB-induced ER stress. This is the first report to show ER signaling in UVB-irradiated keratinocytes.

A class I (Senofilcon A) soft contact lens prevents UVB-induced ocular effects, including cataract, in the rabbit in vivo.

Science.gov (United States)

Giblin, Frank J; Lin, Li-Ren; Leverenz, Victor R; Dang, Loan

2011-06-01

UVB radiation from sunlight is known to be a risk factor for human cataract. The purpose in this study was to investigate the ability of a class I UV-blocking soft contact lens to protect against UVB-induced effects on the ocular tissues of the rabbit in vivo. Eyes of rabbits were exposed to UVB light for 30 minutes (270-360 nm, peak at 310 nm, 1.7 mW/cm(2) on the cornea). Eyes were irradiated in the presence of either a UV-blocking senofilcon A contact lens, a minimally UV-blocking lotrafilcon A contact lens, or no contact lens at all. Effects on the cornea and lens were evaluated at various times after exposure. Eyes irradiated with no contact lens protection showed corneal epithelial cell loss plus lens epithelial cell swelling, vacuole formation, and DNA single-strand breaks, as well as lens anterior subcapsular opacification. The senofilcon A lens protected nearly completely against the UVB-induced effects, whereas the lotrafilcon A lens showed no protection. The results indicate that use of a senofilcon A contact lens is beneficial in protecting ocular tissues of the rabbit against the harmful effects of UVB light, including photokeratitis and cataract.

The effect of topical piperine combined with narrowband UVB on vitiligo treatment: A clinical trial study.

Science.gov (United States)

Shafiee, Anoosh; Hoormand, Mahmood; Shahidi-Dadras, Mohammad; Abadi, Alireza

2018-05-21

Vitiligo is the most common acquired hypopigmentary disease in the community. Piperine as an herbal extract derived from black pepper has strong impact on the melanocyte proliferation and adverse side effects less than synthetic drugs such as corticosteroids. For the first time, this study was aimed to evaluate the effect of topical piperine combined with narrowband ultraviolet B (NB-UVB) on vitiligo treatment. In this double-blind clinical trial, 63 patients with facial vitiligo were randomly divided into 2 groups: treated with piperine (case) and placebo (control). Also, both groups received NB-UVB phototherapy every other day for 3 months. In the case group, 10 patients have burning sensation on their skin areas (p value = .002). Also, redness of the treated areas was observed in 6 patients (p value = .028). Both side effects were temporary. Regarding repigmentation at time intervals of 1, 2, and 3 months after treatment, its level in the case group was significantly higher than the control group (p value topical piperine has more influence on facial vitiligo than that of NB-UVB alone. It could be concluded that the simultaneous use of NB-UVB and topical piperine has a remarkable effect on treatment of vitiligo. Copyright © 2018 John Wiley & Sons, Ltd.

Effects of enhanced UVB on growth and yield of alfalfa (Medic ago Sativa L.) and soybean (Glycine max L.) under field conditions

International Nuclear Information System (INIS)

Al-Oudat, M.; Baydoun, S.A.; Mohamad, A.

1997-04-01

The effects of 20% increase of UVB on growth and yield of alfalfa (Medicago Sativa L.) and two cultivars of soybean (Glycine Max (L.) Mer) under field conditions have been investigated. The increase of UVB dose ranged between 1.746 and 7.112 J/cm 2 during experiment. The results showed that soybean yield decrease by 16% and 31% in A. 3803 and A. 2522 cultivars respectively, under UVB exposure. The dry weight and leaf area were sensitive in the A. 3803 cultivar, while they were tolerant in the A. 2522 cultivar. Alfalfa response to UVB varied during the different stages of growth, whereas the yield was 12% less in the exposed plants. (author). 21 refs., 17 tabs

Octylphenol and UV-B radiation alter larval development and hypothalamic gene expression in the leopard frog (Rana pipiens).

Science.gov (United States)

Crump, Douglas; Lean, David; Trudeau, Vance L

2002-03-01

We assessed octylphenol (OP), an estrogenic endocrine-disrupting chemical, and UV-B radiation, a known stressor in amphibian development, for their effects on hypothalamic gene expression and premetamorphic development in the leopard frog Rana pipiens. Newly hatched tadpoles were exposed for 10 days to OP alone at two different dose levels; to subambient UV-B radiation alone; and to two combinations of OP and UV-B. Control animals were exposed to ethanol vehicle (0.01%) exposure, a subset of tadpoles from each treatment group was raised to metamorphosis to assess differences in body weight and time required for hindlimb emergence. Tadpoles from one of the OP/UV-B combination groups had greater body weight and earlier hindlimb emergence (p weight or hindlimb emergence, indicating a potential mechanism of interaction between OP and UV-B. We hypothesized that the developing hypothalamus might be a potential environmental sensor for neurotoxicologic studies because of its role in the endocrine control of metamorphosis. We used a differential display strategy to identify candidate genes differentially expressed in the hypothalamic region of the exposed tadpoles. Homology cloning was performed to obtain R. pipiens glutamate decarboxylases--GAD65 and GAD67, enzymes involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA). cDNA expression profiles revealed that OP and UV-B affected the levels of several candidate transcripts in tadpole (i.e., Nck, Ash, and phospholipase C gamma-binding protein 4 and brain angiogenesis inhibitor-3) and metamorph (i.e., GAD67, cytochrome C oxidase, and brain angiogenesis inhibitor-2 and -3) brains. This study represents a novel approach in toxicology that combines physiologic and molecular end points and indicates that levels of OP commonly found in the environment and subambient levels of UV-B alter the expression of important hypothalamic genes and disrupt tadpole growth patterns.

Effects of reducing the ambient UV-B radiation in the high Arctic on Salix arctica and Vaccinium uliginosum

DEFF Research Database (Denmark)

Albert, K.R.; Ro-Poulsen, H.; Mikkelsen, Teis Nørgaard

2005-01-01

, transmitting λ > 400 nm) were used to reduce UV-B radiation and UV-B+A respectively. A UV transparent film (Teflon, transmitting λ > 280 nm) and no film were used as controls. Field measurements showed that the plants under Teflon, Mylar and Lexan received app. 91%, 39% and 17% of the ambient UV-B irradiance...

Enzymatic recognition of DNA damage induced by UVB-photosensitized titanium dioxide and biological consequences in Saccharomyces cerevisiae: Evidence for oxidatively DNA damage generation

International Nuclear Information System (INIS)

Pinto, A. Viviana; Deodato, Elder L.; Cardoso, Janine S.; Oliveira, Eliza F.; Machado, Sergio L.; Toma, Helena K.; Leitao, Alvaro C.; Padula, Marcelo de

2010-01-01

Although titanium dioxide (TiO 2 ) has been considered to be biologically inert, finding use in cosmetics, paints and food colorants, recent reports have demonstrated that when TiO 2 is attained by UVA radiation oxidative genotoxic and cytotoxic effects are observed in living cells. However, data concerning TiO 2 -UVB association is poor, even if UVB radiation represents a major environmental carcinogen. Herein, we investigated DNA damage, repair and mutagenesis induced by TiO 2 associated with UVB irradiation in vitro and in vivo using Saccharomyces cerevisiae model. It was found that TiO 2 plus UVB treatment in plasmid pUC18 generated, in addition to cyclobutane pyrimidine dimers (CPDs), specific damage to guanine residues, such as 8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG), which are characteristic oxidatively generated lesions. In vivo experiments showed that, although the presence of TiO 2 protects yeast cells from UVB cytotoxicity, high mutation frequencies are observed in the wild-type (WT) and in an ogg1 strain (deficient in 8-oxoG and FapyG repair). Indeed, after TiO 2 plus UVB treatment, induced mutagenesis was drastically enhanced in ogg1 cells, indicating that mutagenic DNA lesions are repaired by the Ogg1 protein. This effect could be attenuated by the presence of metallic ion chelators: neocuproine or dipyridyl, which partially block oxidatively generated damage occurring via Fenton reactions. Altogether, the results indicate that TiO 2 plus UVB potentates UVB oxidatively generated damage to DNA, possibly via Fenton reactions involving the production of DNA base damage, such as 8-oxo-7,8-dihydroguanine.

The effects of UV-B radiation on European heathland species

DEFF Research Database (Denmark)

Björn, Lars O.; Callaghan, T. V.; Johnsen, Ib

1997-01-01

in the ozone layer) with artificially increased precipitation. The Swedish experiment also involved a study of the interaction between enhanced UV-B radiation and elevated CO2 (600 ppm). These field studies were supported by an outdoor controlled environment study in the United Kingdom involving modulated...

The deceptive nature of UVA tanning versus the modest protective effects of UVB tanning on human skin.

Science.gov (United States)

Miyamura, Yoshinori; Coelho, Sergio G; Schlenz, Kathrin; Batzer, Jan; Smuda, Christoph; Choi, Wonseon; Brenner, Michaela; Passeron, Thierry; Zhang, Guofeng; Kolbe, Ludger; Wolber, Rainer; Hearing, Vincent J

2011-02-01

The relationship between human skin pigmentation and protection from ultraviolet (UV) radiation is an important element underlying differences in skin carcinogenesis rates. The association between UV damage and the risk of skin cancer is clear, yet a strategic balance in exposure to UV needs to be met. Dark skin is protected from UV-induced DNA damage significantly more than light skin owing to the constitutively higher pigmentation, but an as yet unresolved and important question is what photoprotective benefit, if any, is afforded by facultative pigmentation (i.e. a tan induced by UV exposure). To address that and to compare the effects of various wavelengths of UV, we repetitively exposed human skin to suberythemal doses of UVA and/or UVB over 2 weeks after which a challenge dose of UVA and UVB was given. Although visual skin pigmentation (tanning) elicited by different UV exposure protocols was similar, the melanin content and UV-protective effects against DNA damage in UVB-tanned skin (but not in UVA-tanned skin) were significantly higher. UVA-induced tans seem to result from the photooxidation of existing melanin and its precursors with some redistribution of pigment granules, while UVB stimulates melanocytes to up-regulate melanin synthesis and increases pigmentation coverage, effects that are synergistically stimulated in UVA and UVB-exposed skin. Thus, UVA tanning contributes essentially no photoprotection, although all types of UV-induced tanning result in DNA and cellular damage, which can eventually lead to photocarcinogenesis. 2010 John Wiley & Sons A/S. This article is a US Government work and is in the public domain in the USA.

C-terminal region of the UV-B photoreceptor UVR8 initiates signaling through interaction with the COP1 protein

Science.gov (United States)

Cloix, Catherine; Kaiserli, Eirini; Heilmann, Monika; Baxter, Katherine J.; Brown, Bobby A.; O’Hara, Andrew; Smith, Brian O.; Christie, John M.; Jenkins, Gareth I.

2012-01-01

UV-B light initiates photomorphogenic responses in plants. Arabidopsis UV RESISTANCE LOCUS8 (UVR8) specifically mediates these responses by functioning as a UV-B photoreceptor. UV-B exposure converts UVR8 from a dimer to a monomer, stimulates the rapid accumulation of UVR8 in the nucleus, where it binds to chromatin, and induces interaction of UVR8 with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1), which functions with UVR8 to control photomorphogenic UV-B responses. Although the crystal structure of UVR8 reveals the basis of photoreception, it does not show how UVR8 initiates signaling through interaction with COP1. Here we report that a region of 27 amino acids from the C terminus of UVR8 (C27) mediates the interaction with COP1. The C27 region is necessary for UVR8 function in the regulation of gene expression and hypocotyl growth suppression in Arabidopsis. However, UVR8 lacking C27 still undergoes UV-B–induced monomerization in both yeast and plant protein extracts, accumulates in the nucleus in response to UV-B, and interacts with chromatin at the UVR8-regulated ELONGATED HYPOCOTYL5 (HY5) gene. The UV-B–dependent interaction of UVR8 and COP1 is reproduced in yeast cells and we show that C27 is both necessary and sufficient for the interaction of UVR8 with the WD40 domain of COP1. Furthermore, we show that C27 interacts in yeast with the REPRESSOR OF UV-B PHOTOMORPHOGENESIS proteins, RUP1 and RUP2, which are negative regulators of UVR8 function. Hence the C27 region has a key role in UVR8 function. PMID:22988111

Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to UV-B radiation and rare earth

International Nuclear Information System (INIS)

Yan Shengrong; Yang Chunhe; Zhang Yuequn

2009-01-01

[Objective] The aim was to provide strategies for development of rare earth and control of environmental pollution. [Method] Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to UV-B radiation and rare earth were studied through hydroponics in laboratory. [Result] The results showed that under irradiation of UV-B(T1-0.15 W/m2 and T2-0.45 W/m2), chlorophyll and indole-3-acetic acid(IAA) contents firstly decreased during the stress phase (1-5d) and then increased during the restoration phase (6-9d) while contents of malonadialdehyde(MDA) and abscisic acid(ABA) gradually increased during the imposition of UV-B radiation (1-5d) and subsequently decreased during recovery from UV-B stress (6-9d) . With adding of La (Ⅲ) with the concentration of 20mg•L-1, the decline/rise trend of chlorophyll, IAA, MDA and ABA contents was slowed down during the stress period while the rise/decline speed was accelerated during the recovery period. [Conclusion] It suggests that the regulation of La (Ⅲ) on membrane lipid peroxidation and endogenous hormones could increase chlorophyll and IAA contents, improve the metabolism of reactive oxygen species (ROS), inhibit membrane lipid peroxidation, decrease the accumulation amount of ABA and alleviate injury of UV-B radiation to soybean seedlings. Further, the protective potential of La (Ⅲ) was better under low UV-B radiation than under high one

Long-term structural canopy changes sustain net photosynthesis per ground area in high arctic Vaccinium uliginosum exposed to changes in near-ambient UV-B levels

DEFF Research Database (Denmark)

Boesgaard, Kristine Stove; Albert, Kristian Rost; Ro-Poulsen, Helge

2012-01-01

Full recovery of the ozone layer is not expected for several decades and consequently, the incoming level of solar ultraviolet-B (UV-B) will only slowly be reduced. Therefore to investigate the structural and photosynthetic responses to changes in solar UV-B we conducted a 5-year UV-B exclusion s...

Influence of UV-B radiation on developmental changes, ethylene, CO2 flux and polyamines in cv. Doyenne d'Hiver pear shoots grown in vitro

International Nuclear Information System (INIS)

Predieri, S.; Krizek, D.T.; Wang, C.Y.; Mirecki, R.M.; Zimmerman, R.H.

1993-01-01

In vitro shoots of cv. Doyenne d'Hiver pear (Pyrus communis L.) were irradiated under controlled environments for 6 h per day at 5 different levels of biologically effective UV-B radiation (UV-B BE ). UV-B exposure caused a progressive increase in apical necrosis above background levels and stimulated leaf abscission. Shoots grown for 2 weeks at 7. 8 mol m −2 day −1 of photosynthetic photon flux (PPF) and treated with 8. 4 or 12. 0 kJ m −2 day −1 UV-B BE produced up to 4 times more ethylene than those given 2. 2 or 5. 1 kJ m −2 day −1 UV-B BE or untreated controls. Exposure of shoots to 12 kJ m −2 day −1 of UV-BBE caused an increase in free putreseine content after 4 to 14 days of irradiation. Shoots showed a decrease in CO2 uptake after 3 days of UV-B: thereafter, they appeared to recover their photosynthetic capacity. Under typical PPF conditions used in micropropagation (90 μmol m −2 s −1 ). 8. 4 kJ m −2 day −1 of UV-B radiation was injurious to realatively tender tissues of in vitro pear shoots: increasing the level of UV-B BE to 12 kJ m −2 day −1 produced even more adverse effects. (author)

Soybean resistance to stink bugs (Nezara viridula and Piezodorus guildinii) increases with exposure to solar UV-B radiation and correlates with isoflavonoid content in pods under field conditions.

Science.gov (United States)

Zavala, Jorge A; Mazza, Carlos A; Dillon, Francisco M; Chludil, Hugo D; Ballaré, Carlos L

2015-05-01

Solar UV-B radiation (280-315 nm) has a significant influence on trophic relationships in natural and managed ecosystems, affecting plant-insect interactions. We explored the effects of ambient UV-B radiation on the levels of herbivory by stink bugs (Nezara viridula and Piezodorus guildinii) in field-grown soybean crops. The experiments included two levels of UV-B radiation (ambient and attenuated UV-B) and four soybean cultivars known to differ in their content of soluble leaf phenolics. Ambient UV-B radiation increased the accumulation of the isoflavonoids daidzin and genistin in the pods of all cultivars. Soybean crops grown under attenuated UV-B had higher numbers of unfilled pods and damaged seeds than crops grown under ambient UV-B radiation. Binary choice experiments with soybean branches demonstrated that stink bugs preferred branches of the attenuated UV-B treatment. We found a positive correlation between percentage of undamaged seeds and the contents of daidzin and genistin in pods. Our results suggest that constitutive and UV-B-induced isoflavonoids increase plant resistance to stink bugs under field conditions. © 2014 John Wiley & Sons Ltd.

Long-term uvb forecasting on the basis of spectral and broad-band measurements

Science.gov (United States)

Bérces, A.; Gáspár, S.; Kovács, G.; Rontó, G.

2003-04-01

The stratospheric ozone concentration has been investigated by several methods, e.g. determinations of the ozone layer using a network of ground based spectrophotometers, of the Dobson and the Brewer types. These data indicate significant decrease of the ozone layer superimposed by much larger seasonal changes at specific geographical locations. The stratospheric ozone plays an important role in the attenuation of the short-wavelength components of the solar spectrum, thus the consequence of the decreased ozone layer is an increased UVB level. Various pyranometers measuring the biological effect of environmental UV radiation have been constructed with spectral sensitivities close to the erythema action spectrum defined by the CIE. Using these erythemally weighted broad-band instruments to detect the tendency of UVB radiation controversial data have been found. To quantify the biological risk due to environmental UV radiation it is reasonable to weight the solar spectrum by the spectral sensitivity of the DNA damage taking into account the high DNA-sensitivity at the short wavelength range of the solar spectrum. Various biological dosimeters have been developed e.g. polycrystalline uracil thin layer. These are usually simple biological systems or components of them. Their UV sensitivity is a consequence of the DNA-damage. Biological dosimeters applied for long-term monitoring are promising tools for the assessment of the biological hazard. Simultaneous application of uracil dosimeters and Robertson-Berger meters can be useful to predict the increasing tendency of the biological UV exposure more precisely. The ratio of the biologically effective dose obtained by the uracil dosimeter (a predominately UVB effect) and by the Robertson-Berger meter (insensitive to changes below 300 nm) is a sensitive method for establishing changes in UVB irradiance due to changes in ozone layer.

Enzymatic recognition of DNA damage induced by UVB-photosensitized titanium dioxide and biological consequences in Saccharomyces cerevisiae: evidence for oxidatively DNA damage generation.

Science.gov (United States)

Pinto, A Viviana; Deodato, Elder L; Cardoso, Janine S; Oliveira, Eliza F; Machado, Sérgio L; Toma, Helena K; Leitão, Alvaro C; de Pádula, Marcelo

2010-06-01

Although titanium dioxide (TiO(2)) has been considered to be biologically inert, finding use in cosmetics, paints and food colorants, recent reports have demonstrated that when TiO(2) is attained by UVA radiation oxidative genotoxic and cytotoxic effects are observed in living cells. However, data concerning TiO(2)-UVB association is poor, even if UVB radiation represents a major environmental carcinogen. Herein, we investigated DNA damage, repair and mutagenesis induced by TiO(2) associated with UVB irradiation in vitro and in vivo using Saccharomyces cerevisiae model. It was found that TiO(2) plus UVB treatment in plasmid pUC18 generated, in addition to cyclobutane pyrimidine dimers (CPDs), specific damage to guanine residues, such as 8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG), which are characteristic oxidatively generated lesions. In vivo experiments showed that, although the presence of TiO(2) protects yeast cells from UVB cytotoxicity, high mutation frequencies are observed in the wild-type (WT) and in an ogg1 strain (deficient in 8-oxoG and FapyG repair). Indeed, after TiO(2) plus UVB treatment, induced mutagenesis was drastically enhanced in ogg1 cells, indicating that mutagenic DNA lesions are repaired by the Ogg1 protein. This effect could be attenuated by the presence of metallic ion chelators: neocuproine or dipyridyl, which partially block oxidatively generated damage occurring via Fenton reactions. Altogether, the results indicate that TiO(2) plus UVB potentates UVB oxidatively generated damage to DNA, possibly via Fenton reactions involving the production of DNA base damage, such as 8-oxo-7,8-dihydroguanine. Copyright 2010 Elsevier B.V. All rights reserved.

Enzymatic recognition of DNA damage induced by UVB-photosensitized titanium dioxide and biological consequences in Saccharomyces cerevisiae: Evidence for oxidatively DNA damage generation

Energy Technology Data Exchange (ETDEWEB)

Pinto, A. Viviana, E-mail: alicia.pinto@incqs.fiocruz.br [Laboratorio de Diagnostico Molecular e Hematologia, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21941-540, Rio de Janeiro (Brazil); Laboratorio de Radiobiologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21949-900, Rio de Janeiro (Brazil); Deodato, Elder L. [Laboratorio de Diagnostico Molecular e Hematologia, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21941-540, Rio de Janeiro (Brazil); Laboratorio de Radiobiologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21949-900, Rio de Janeiro (Brazil); Cardoso, Janine S. [Laboratorio de Radiobiologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21949-900, Rio de Janeiro (Brazil); Oliveira, Eliza F.; Machado, Sergio L.; Toma, Helena K. [Laboratorio de Diagnostico Molecular e Hematologia, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21941-540, Rio de Janeiro (Brazil); Leitao, Alvaro C. [Laboratorio de Radiobiologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21949-900, Rio de Janeiro (Brazil); Padula, Marcelo de [Laboratorio de Diagnostico Molecular e Hematologia, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21941-540, Rio de Janeiro (Brazil)

2010-06-01

Although titanium dioxide (TiO{sub 2}) has been considered to be biologically inert, finding use in cosmetics, paints and food colorants, recent reports have demonstrated that when TiO{sub 2} is attained by UVA radiation oxidative genotoxic and cytotoxic effects are observed in living cells. However, data concerning TiO{sub 2}-UVB association is poor, even if UVB radiation represents a major environmental carcinogen. Herein, we investigated DNA damage, repair and mutagenesis induced by TiO{sub 2} associated with UVB irradiation in vitro and in vivo using Saccharomyces cerevisiae model. It was found that TiO{sub 2} plus UVB treatment in plasmid pUC18 generated, in addition to cyclobutane pyrimidine dimers (CPDs), specific damage to guanine residues, such as 8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG), which are characteristic oxidatively generated lesions. In vivo experiments showed that, although the presence of TiO{sub 2} protects yeast cells from UVB cytotoxicity, high mutation frequencies are observed in the wild-type (WT) and in an ogg1 strain (deficient in 8-oxoG and FapyG repair). Indeed, after TiO{sub 2} plus UVB treatment, induced mutagenesis was drastically enhanced in ogg1 cells, indicating that mutagenic DNA lesions are repaired by the Ogg1 protein. This effect could be attenuated by the presence of metallic ion chelators: neocuproine or dipyridyl, which partially block oxidatively generated damage occurring via Fenton reactions. Altogether, the results indicate that TiO{sub 2} plus UVB potentates UVB oxidatively generated damage to DNA, possibly via Fenton reactions involving the production of DNA base damage, such as 8-oxo-7,8-dihydroguanine.

Protective Effects of LSGYGP from Fish Skin Gelatin Hydrolysates on UVB-Induced MEFs by Regulation of Oxidative Stress and Matrix Metalloproteinase Activity.

Science.gov (United States)

Ma, Qingyu; Liu, Qiuming; Yuan, Ling; Zhuang, Yongliang

2018-03-28

A previous study has shown that tilapia fish skin gelatin hydrolysates inhibited photoaging in vivo, and that, Leu-Ser-Gly-Tyr-Gly-Pro (LSGYGP) identified in the hydrolysate had a high hydroxyl radical scavenging activity. In this study, activities of LSGYGP were further evaluated using ultraviolet B (UVB)-induced mouse embryonic fibroblasts (MEFs). UVB irradiation significantly increased the intercellular reactive oxygen species (ROS) production and matrix metalloproteinases (MMPs) activities and decreased the content of collagen in MEFs. LSGYGP reduced the intercellular ROS generation in UVB-induced MEFs. Meanwhile, the decrease of superoxide dismutase (SOD) activity and the increase of malondiaidehyde (MDA) content were inhibited by LSGYGP. LSGYGP reduced MMP-1 and MMP-9 activities in a dose-dependent manner. Molecular docking simulation indicated that LSGYGP inhibited MMPs activities by docking the active sites of MMP-1 and MMP-9. Furthermore, LSGYGP also affected the intercellular phosphorylation of UVB-induced the mitogen-activated protein kinase pathway. LSGYGP could protect collagen synthesis in MEFs under UVB irradiation by inhibiting oxidative stress and regulating MMPs activities.

Protective Effects of LSGYGP from Fish Skin Gelatin Hydrolysates on UVB-Induced MEFs by Regulation of Oxidative Stress and Matrix Metalloproteinase Activity

Directory of Open Access Journals (Sweden)

Qingyu Ma

2018-03-01

Full Text Available A previous study has shown that tilapia fish skin gelatin hydrolysates inhibited photoaging in vivo, and that, Leu-Ser-Gly-Tyr-Gly-Pro (LSGYGP identified in the hydrolysate had a high hydroxyl radical scavenging activity. In this study, activities of LSGYGP were further evaluated using ultraviolet B (UVB-induced mouse embryonic fibroblasts (MEFs. UVB irradiation significantly increased the intercellular reactive oxygen species (ROS production and matrix metalloproteinases (MMPs activities and decreased the content of collagen in MEFs. LSGYGP reduced the intercellular ROS generation in UVB-induced MEFs. Meanwhile, the decrease of superoxide dismutase (SOD activity and the increase of malondiaidehyde (MDA content were inhibited by LSGYGP. LSGYGP reduced MMP-1 and MMP-9 activities in a dose-dependent manner. Molecular docking simulation indicated that LSGYGP inhibited MMPs activities by docking the active sites of MMP-1 and MMP-9. Furthermore, LSGYGP also affected the intercellular phosphorylation of UVB-induced the mitogen-activated protein kinase pathway. LSGYGP could protect collagen synthesis in MEFs under UVB irradiation by inhibiting oxidative stress and regulating MMPs activities.

Medición y predicción de la radiación solar global UV-B bajo cielos claros y sin nubes

Directory of Open Access Journals (Sweden)

Jaime Wright Gilmore

2016-03-01

Full Text Available Se presentan mediciones experimentales de la radiación solar ultravioleta en el rango B del espectro solar (UV-B y la radiación ultravioleta en el rango total RUV (UV-A+UV-B en días claros y sin nubes en Heredia, Costa Rica. Se utilizó una radiómetro UV-B, que mide la radiación solar en el rango espectral 280-315 nm, y un radiómetro RUV, que mide la radiación solar en el rango espectral 280-385 nm. La dependencia entre entre UV-B y RUV también fue investigada, y se encontró un excelente grado de asociación entre ambas. Además se detalló que UV-B representa solamente un 5,4% de RUV, a pesar de que UV-B es mil veces más potente que UV-A. Los valores de UV-B medidos in situ fueron comparados con los valores predichos por un modelo atmosférico espectral, el cual utiliza como datos de entrada: la hora del día, la latitud, la altitud, el albedo superficial, la distancia Tierra-Sol, la turbiedad atmosférica y el ozono atmosférico. La comparación entre los valores medidos y predichos dio resultados satisfactorios.

Solar UV-B radiation and ethylene play a key role in modulating effective defenses against Anticarsia gemmatalis larvae in field-grown soybean.

Science.gov (United States)

Dillon, Francisco M; Tejedor, M Daniela; Ilina, Natalia; Chludil, Hugo D; Mithöfer, Axel; Pagano, Eduardo A; Zavala, Jorge A

2018-02-01

Solar UV-B radiation has been reported to enhance plant defenses against herbivore insects in many species. However, the mechanism and traits involved in the UV-B mediated increment of plant resistance are unknown in crops species, such as soybean. Here, we studied defense-related responses in undamaged and Anticarsia gemmatalis larvae-damaged leaves of two soybean cultivars grown under attenuated or full solar UV-B radiation. We determined changes in jasmonates, ethylene (ET), salicylic acid, trypsin protease inhibitor activity, flavonoids, and mRNA expression of genes related with defenses. ET emission induced by Anticarsia gemmatalis damage was synergistically increased in plants grown under solar UV-B radiation and was positively correlated with malonyl genistin concentration, trypsin proteinase inhibitor activity and expression of IFS2, and the pathogenesis protein PR2, while was negatively correlated with leaf consumption. The precursor of ET, aminocyclopropane-carboxylic acid, applied exogenously to soybean was sufficient to strongly induce leaf isoflavonoids. Our results showed that in field-grown soybean isoflavonoids were regulated by both herbivory and solar UV-B inducible ET, whereas flavonols were regulated by solar UV-B radiation only and not by herbivory or ET. Our study suggests that, although ET can modulate UV-B-mediated priming of inducible plant defenses, some plant defenses, such as isoflavonoids, are regulated by ET alone. © 2017 John Wiley & Sons Ltd.

The measurement and analysis of normal incidence solar UVB radiation and its application to the photoclimatherapy protocol for psoriasis at the Dead Sea, Israel.

Science.gov (United States)

Kudish, Avraham I; Harari, Marco; Evseev, Efim G

2011-01-01

The broad-band normal incidence UVB beam radiation has been measured at Neve Zohar, Dead Sea basin, using a prototype tracking instrument composed of a Model 501A UV-Biometer mounted on an Eppley Solar Tracker Model St-1. The diffuse and beam fraction of the solar global UVB radiation have been determined using the concurrently measured solar global UVB radiation. The diffuse fraction was observed to exceed 80% throughout the year. The application of the results of these measurements to the possible revision of the photoclimatherapy protocol for psoriasis patients at the Dead Sea medical spas is now under investigation. The suggested revision would enable the sun-exposure treatment protocol to take advantage of the very high diffuse fraction by allowing the patient to receive the daily dose of UVB radiation without direct exposure to the sun, viz. receive the diffuse UVB radiation under a sunshade. This would require an increase in sun-exposure time intervals, as the UVB radiation intensity beneath a sunshade is less than that on an exposed surface. © 2010 The Authors. Photochemistry and Photobiology © 2010 The American Society of Photobiology.

The co-application effects of fullerene and ascorbic acid on UV-B irradiated mouse skin

International Nuclear Information System (INIS)

Ito, Shinobu; Itoga, Kazuyoshi; Yamato, Masayuki; Akamatsu, Hirohiko; Okano, Teruo

2010-01-01

The role of fullerene as a pro-oxidant or anti-oxidant in Ultraviolet B ray (UV-B)-induced disorders in mouse skin was investigated. Fullerene gave no photo-toxic effect to UV-B-irradiated mouse skin. Since erythema was concentrated at the pore circumference in a UV-B irradiation experiment in mouse skin, the sebaceous gland pairs was strongly implicated as a site for the generation of reactive oxygen species (ROS). In a histological evaluation of the skin stained with CH 3 MDFDA (ROS index) and YO-Pro-1 (apoptosis index), the fluorescence intensity of a sebaceous gland significantly increased with UV-B irradiation. With the application of fullerene to UV-irradiated mouse skin, no toxicity was recognized in comparison with the control, and erythema, the ROS index, and the apoptosis index decrease with the application of fullerene. Ascorbyl radical (AA·) increased with the application of ascorbate (AA) to UV-B-irradiated mouse skin, and AA· decreased with the application of fullerene. The co-application of AA and fullerene, which suppressed AA· in vitro, significantly suppressed erythema, and also suppressed both the ROS index and apoptosis index in mouse skin after UV-B irradiation. In both mouse skin at 48 h after UV-B irradiation and in an attempt to reproduce this phenomenon artificially in vitro, a similar high AA· peak (AA·/H· > 4) was observed in electron spin resonance (ESR) charts. The binding of fullerene with AA impairs the Fenton reaction between AA and Fe-protein based on the observation of ascorbate-specific UV absorption and a linear equation for the calibration curve. Therefore, fullerene may impair the intercalation of AA to a heme pocket by binding with AA. These results suggest that the co-application of AA and fullerene is effective against oxidative skin damage caused by UV-B irradiation, and the development of an AA· inhibitor such as fullerene should be useful for reducing organ damage associated with Fe-protein oxidation.

Responses of photosynthetic properties and chloroplast ultrastructure of two moss crusts from a desert biological soil crust to supplementary UV-B radiation

Science.gov (United States)

Hui, Rong; Li, Xinrong; Zhao, Yang; Pan, Yanxia

2016-04-01

Our understanding of plant responses to supplementary ultraviolet-B (UV-B) radiation due to stratospheric ozone depletion has improved over recent decades. However, research on biological soil crusts (BSCs) is scarce and it remains controversial. Laboratory studies were conducted to investigate the influence of UV-B radiation on the Bryum argenteum and Didymodon vinealis isolated from BSCs, which are both dominant species in moss crusts found within patches of shrubs and herbs in the Tengger Desert of northern China. The aim of the current work was to evaluate whether supplementary UV-B radiation affected photosynthetic properties and chloroplast ultrastructure of two moss crusts and whether response differences were observed between the crusts. Four levels of UV-B radiation of 2.75 (control), 3.08, 3.25, and 3.41 W m-2 was achieved using fluorescence tube systems for 10 days, simulating 0, 6, 9, and 12% of stratospheric ozone at the latitude of Shapotou, respectively. We measured photosynthetic apparatus as assessed by chlorophyll a fluorescence parameters, photosynthetic pigment contents, and observations of chloroplast ultrastructure. Additionally, soluble proteins and UV-B absorbing compounds were simultaneously investigated. The results of this study showed that chlorophyll a fluorescence parameters (i.e., the maximal quantum yield of PSII photochemistry, the effective quantum yield of PSII photochemistry, and photochemical quenching coefficient), photosynthetic pigment contents, soluble protein contents, total flavonoid contents and the ultrastructure were negatively influenced by elevated UV-B radiation and the degree of detrimental effects significantly increased with the intensity of UV-B radiation. Moreover, results demonstrated that the negative effects on photosynthesis and chloroplast ultrastructure were more serious in B. argenteum than that in D. vinealis. These results may not only provide a potential mechanism for supplemental UV-B effects on

Increase of vitamin D2 by UV-B exposure during the growth phase of white button mushroom (Agaricus bisporus)

DEFF Research Database (Denmark)

Kristensen, Hanne; Rosenqvist, Eva S. K.; Jakobsen, Jette

2012-01-01

Background: Mushrooms are the only non-animal food source of vitamin D. Wild mushrooms have naturally high vitamin D2 content, and cultivated mushrooms produce vitamin D2 from ergosterol when exposed to supplementary UV-B during the post-harvest phase. Objectives: This study investigated...... with exposure to supplementary UV-B just prior to harvest in the range of 0-2,400 mJ cm-2. Mushrooms grew for 2 days with or without repeated UV-B exposure each day. Vitamin D2 and growth rate were determined. Some mushrooms were post-harvest treated by exposure at 200 mJ cm-2 supplementary UV-B or natural...... sunlight, prior to vitamin D2 determination. Results: The content of vitamin D2 was 0.2-164 µg 100 g-1 fresh weight (FW), and there was a linear relationship between UV-dose up to 1,000 mJ cm-2 and vitamin D2 content. The fast growth rate of the mushrooms diluted the vitamin D2 from 24 to 3 µg 100 g-1...

Differential physiological and biochemical responses of two cyanobacteria Nostoc muscorum and Phormidium foveolarum against oxyfluorfen and UV-B radiation.

Science.gov (United States)

Sheeba; Pratap Singh, Vijay; Kumar Srivastava, Prabhat; Mohan Prasad, Sheo

2011-10-01

In the present study, degree of tolerance and tolerance strategies of two paddy field cyanobacteria viz. Nostoc muscorum and Phormidium foveolarum against oxyfluorfen (10 and 20 μg ml(-1)) and UV-B (7.2 kJ m(-2)d(-1)) stress were investigated. Oxyfluorfen and UV-B decreased growth, photosynthesis, nutrient uptake, nitrate reductase, acid and alkaline phosphatase activities, which accompanied with the increase in the level of oxidative stress. However, growth was more affected in N. muscorum than P. foveolarum. Antioxidants exhibited differential responses against oxyfluorfen and UV-B stress. Ascorbate and proline levels were higher in P. foveolarum. A protein of 66 kDa was expressed in N. muscorum, however, it was absent in P. foveolarum than those of N. muscorum. Besides this, a protein of 29 kDa appeared in P. foveolarum under all the treatments, but it was present only in control cells of N. muscorum cells. Overall results indicated resistant nature of P. foveolarum against oxyfluorfen and UV-B stress in comparison to N. muscorum. Copyright © 2011 Elsevier Inc. All rights reserved.

Dose/dose-rate responses of shrimp larvae to UV-B radiation

International Nuclear Information System (INIS)

Damkaer, D.M.

1981-01-01

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm -2 sub([DNA]) irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm -2 sub([DNA]). Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation. (orig.)

Dose/dose-rate responses of shrimp larvae to UV-B radiation

Energy Technology Data Exchange (ETDEWEB)

Damkaer, D.M.; Dey, D.B.; Heron, G.A.

1981-01-01

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm/sup -2/sub((DNA)) irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm/sup -2/sub((DNA)). Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation.

Enhancement of UVB radiation-mediated apoptosis by knockdown of cytosolic NADP+-dependent isocitrate dehydrogenase in HaCaT cells.

Science.gov (United States)

Lee, Su Jeong; Park, Jeen-Woo

2014-04-01

Ultraviolet B (UVB) radiation induces the production of reactive oxygen species (ROS) that promote apoptotic cell death. We showed that cytosolic NADP+-dependent isocitrate dehydrogenase (IDPc) plays an essential role in the control of cellular redox balance and defense against oxidative damage, by supplying NADPH for antioxidant systems. In this study, we demonstrated that knockdown of IDPc expression by RNA interference enhances UVB-induced apoptosis of immortalized human HaCaT keratinocytes. This effect manifested as DNA fragmentation, changes in cellular redox status, mitochondrial dysfunction, and modulation of apoptotic marker expression. Based on our findings, we suggest that attenuation of IDPc expression may protect skin from UVB-mediated damage, by inducing the apoptosis of UV-damaged cells.

Galectin-7 overexpression is associated with the apoptotic process in UVB-induced sunburn keratinocytes

Science.gov (United States)

Bernerd, Francoise; Sarasin, Alain; Magnaldo, Thierry

1999-01-01

Galectin-7 is a β-galactoside binding protein specifically expressed in stratified epithelia and notably in epidermis, but barely detectable in epidermal tumors and absent from squamous carcinoma cell lines. Galectin-7 gene is an early transcriptional target of the tumor suppressor protein P53 [Polyak, K., Xia, Y., Zweier, J., Kinzler, K. & Vogelstein, B. (1997) Nature (London) 389, 300–305]. Because p53 transcriptional activity is increased by genotoxic stresses we have examined the possible effects of ultraviolet radiations (UVB) on galectin-7 expression in epidermal keratinocytes. The amounts of galectin-7 mRNA and protein are increased rapidly after UVB irradiation of epidermal keratinocytes. The increase of galectin-7 is parallel to P53 stabilization. UVB irradiation of skin reconstructed in vitro and of human skin ex vivo demonstrates that galectin-7 overexpression is associated with sunburn/apoptotic keratinocytes. Transfection of a galectin-7 expression vector results in a significant increase in terminal deoxynucleotidyltransferase-mediated UTP end labeling-positive keratinocytes. The present findings demonstrate a keratinocyte-specific protein involved in the UV-induced apoptosis, an essential process in the maintenance of epidermal homeostasis. PMID:10500176

UVB irradiation does not directly induce detectable changes of DNA methylation in human keratinocytes [v1; ref status: indexed, http://f1000r.es/np

Directory of Open Access Journals (Sweden)

Christoph Lahtz

2013-02-01

Full Text Available Unprotected exposure to UVB radiation from the sun and the resulting DNA damage are thought to be responsible for physiological changes in the skin and for a variety of skin cancers, including basal cell and squamous cell carcinoma and malignant melanoma. Although the mutagenic effects of UVB have been well documented and studied mechanistically, there is only limited information as to whether UV light may also be responsible for inducing epigenetic changes in the genome of exposed cells. DNA methylation is a stable epigenetic modification involved in gene control. To study the effects of UVB radiation on DNA methylation, we repeatedly exposed normal human keratinocytes to a UVB light source. After a recovery period, we analyzed global DNA methylation patterns in the irradiated and control cells using the methylated-CpG island recovery assay (MIRA method in combination with high-resolution microarrays. Bioinformatics analysis revealed only a limited number of possible differences between UVB-exposed and control cells. However, these minor apparent changes could not be independently confirmed by bisulfite sequencing-based approaches. This study reveals that UVB irradiation of keratinocytes has no recognizable global effect on DNA methylation patterns and suggests that changes in DNA methylation, as observed in skin cancers, are not immediate consequences of human exposure to solar UVB irradiation.

Row orientation effect on UV-B, UV-A and PAR solar irradiation components in vineyards at Tuscany, Italy

Science.gov (United States)

Grifoni, D.; Carreras, G.; Zipoli, G.; Sabatini, F.; Dalla Marta, A.; Orlandini, S.

2008-11-01

Besides playing an essential role in plant photosynthesis, solar radiation is also involved in many other important biological processes. In particular, it has been demonstrated that ultraviolet (UV) solar radiation plays a relevant role in grapevines ( Vitis vinifera) in the production of certain important chemical compounds directly responsible for yield and wine quality. Moreover, the exposure to UV-B radiation (280-320 nm) can affect plant-disease interaction by influencing the behaviour of both pathogen and host. The main objective of this research was to characterise the solar radiative regime of a vineyard, in terms of photosynthetically active radiation (PAR) and UV components. In this analysis, solar spectral UV irradiance components, broadband UV (280-400 nm), spectral UV-B and UV-A (320-400 nm), the biological effective UVBE, as well as the PAR (400-700 nm) component, were all considered. The diurnal patterns of these quantities and the UV-B/PAR and UV-B/UV-A ratios were analysed to investigate the effect of row orientation of the vineyard in combination with solar azimuth and elevation angles. The distribution of PAR and UV irradiance at various heights of the vertical sides of the rows was also studied. The results showed that the highest portion of plants received higher levels of daily radiation, especially the UV-B component. Row orientation of the vines had a pronounced effect on the global PAR received by the two sides of the rows and, to a lesser extent, UV-A and UV-B. When only the diffused component was considered, this geometrical effect was greatly attenuated. UV-B/PAR and UV-A/PAR ratios were also affected, with potential consequences on physiological processes. Because of the high diffusive capacity of the UV-B radiation, the UV-B/PAR ratio was significantly lower on the plant portions exposed to full sunlight than on those in the shade.

The response of human skin commensal bacteria as a reflection of UV radiation: UV-B decreases porphyrin production.

Directory of Open Access Journals (Sweden)

Yanhan Wang

Full Text Available Recent global radiation fears reflect the urgent need for a new modality that can simply determine if people are in a radiation risk of developing cancer and other illnesses. Ultraviolet (UV radiation has been thought to be the major risk factor for most skin cancers. Although various biomarkers derived from the responses of human cells have been revealed, detection of these biomarkers is cumbersome, probably requires taking live human tissues, and varies significantly depending on human immune status. Here we hypothesize that the reaction of Propionibacterium acnes (P. acnes, a human resident skin commensal, to UV radiation can serve as early surrogate markers for radiation risk because the bacteria are immediately responsive to radiation. In addition, the bacteria can be readily accessible and exposed to the same field of radiation as human body. To test our hypothesis, P. acnes was exposed to UV-B radiation. The production of porphyrins in P. acnes was significantly reduced with increasing doses of UV-B. The porphyrin reduction can be detected in both P. acnes and human skin bacterial isolates. Exposure of UV-B to P. acnes- inoculated mice led to a significant decrease in porphyrin production in a single colony of P. acnes and simultaneously induced the formation of cyclobutane pyrimidine dimers (CPD in the epidermal layers of mouse skin. Mass spectrometric analysis via a linear trap quadrupole (LTQ-Orbitrap XL showed that five peptides including an internal peptide (THLPTGIVVSCQNER of a peptide chain release factor 2 (RF2 were oxidized by UV-B. Seven peptides including three internal peptides of 60 kDa chaperonin 1 were de-oxidized by UV-B. When compared to UV-B, gamma radiation also decreased the porphyrin production of P. acnes in a dose-dependent manner, but induced a different signature of protein oxidation/de-oxidation. We highlight that uncovering response of skin microbiome to radiation will facilitate the development of pre

The response of human skin commensal bacteria as a reflection of UV radiation: UV-B decreases porphyrin production.

Science.gov (United States)

Wang, Yanhan; Zhu, Wenhong; Shu, Muya; Jiang, Yong; Gallo, Richard L; Liu, Yu-Tsueng; Huang, Chun-Ming

2012-01-01

Recent global radiation fears reflect the urgent need for a new modality that can simply determine if people are in a radiation risk of developing cancer and other illnesses. Ultraviolet (UV) radiation has been thought to be the major risk factor for most skin cancers. Although various biomarkers derived from the responses of human cells have been revealed, detection of these biomarkers is cumbersome, probably requires taking live human tissues, and varies significantly depending on human immune status. Here we hypothesize that the reaction of Propionibacterium acnes (P. acnes), a human resident skin commensal, to UV radiation can serve as early surrogate markers for radiation risk because the bacteria are immediately responsive to radiation. In addition, the bacteria can be readily accessible and exposed to the same field of radiation as human body. To test our hypothesis, P. acnes was exposed to UV-B radiation. The production of porphyrins in P. acnes was significantly reduced with increasing doses of UV-B. The porphyrin reduction can be detected in both P. acnes and human skin bacterial isolates. Exposure of UV-B to P. acnes- inoculated mice led to a significant decrease in porphyrin production in a single colony of P. acnes and simultaneously induced the formation of cyclobutane pyrimidine dimers (CPD) in the epidermal layers of mouse skin. Mass spectrometric analysis via a linear trap quadrupole (LTQ)-Orbitrap XL showed that five peptides including an internal peptide (THLPTGIVVSCQNER) of a peptide chain release factor 2 (RF2) were oxidized by UV-B. Seven peptides including three internal peptides of 60 kDa chaperonin 1 were de-oxidized by UV-B. When compared to UV-B, gamma radiation also decreased the porphyrin production of P. acnes in a dose-dependent manner, but induced a different signature of protein oxidation/de-oxidation. We highlight that uncovering response of skin microbiome to radiation will facilitate the development of pre-symptomatic diagnosis

Elevated level of polysaccharides in a high level UV-B tolerant cell ...

African Journals Online (AJOL)

Jane

2011-04-26

Apr 26, 2011 ... A cell line of Bupleurum scorzonerifolium Willd with high level ... mechanisms to repair UV-induced damages via repairing ... for treatment or prevention of solar radiation. ..... working as both UV-B absorbing compounds and.

Impact of UV-B (290-320 nm) radiation on photosynthesis-mediated uptake of 15N-ammonia and 15N-nitrate of several marine diatoms

International Nuclear Information System (INIS)

Doehler, G.; Stolter, H.

1986-01-01

The marine diatoms Ditylum brigthwellii, Lithodesmium variabile, Odontella sinensis, Synedra planctonica and Thalassiosira rotula grown at 18 0 C under normal air conditions (0.035 vol.% CO 2 ) were exposed to different levels (439 and 717 J m -2 d -1 , weighted) of UV-B radiation for 2 d (5 h/d). Pigmentation, protein and total nitrogen content were reduced linearly to the dose of UV-B radiation. Photosynthesis-mediated uptake of 15 N-ammonia was more affected by UV-B irradiance in all tested diatoms than that of 15 N-nitrate. A species-dependent behavior in the assimilation of inorganic nitrogenous compounds has been observed: Synedra was a very sensitive species to UV-B radiation whereas the same UV-B doses had no effect on the assimilation rate of ammonia and nitrate of the Lithodesmium cells. The results were discussed with reference to the inhibition of the enzymes of the nitrogen metabolism. (author)

Proteomic profiling of human keratinocytes undergoing UVB-induced alternative differentiation reveals TRIpartite Motif Protein 29 as a survival factor.

Directory of Open Access Journals (Sweden)

Véronique Bertrand-Vallery

Full Text Available BACKGROUND: Repeated exposures to UVB of human keratinocytes lacking functional p16(INK-4a and able to differentiate induce an alternative state of differentiation rather than stress-induced premature senescence. METHODOLOGY/PRINCIPAL FINDINGS: A 2D-DIGE proteomic profiling of this alternative state of differentiation was performed herein at various times after the exposures to UVB. Sixty-nine differentially abundant protein species were identified by mass spectrometry, many of which are involved in keratinocyte differentiation and survival. Among these protein species was TRIpartite Motif Protein 29 (TRIM29. Increased abundance of TRIM29 following UVB exposures was validated by Western blot using specific antibody and was also further analysed by immunochemistry and by RT-PCR. TRIM29 was found very abundant in keratinocytes and reconstructed epidermis. Knocking down the expression of TRIM29 by short-hairpin RNA interference decreased the viability of keratinocytes after UVB exposure. The abundance of involucrin mRNA, a marker of late differentiation, increased concomitantly. In TRIM29-knocked down reconstructed epidermis, the presence of picnotic cells revealed cell injury. Increased abundance of TRIM29 was also observed upon exposure to DNA damaging agents and PKC activation. The UVB-induced increase of TRIM29 abundance was dependent on a PKC signaling pathway, likely PKCdelta. CONCLUSIONS/SIGNIFICANCE: These findings suggest that TRIM29 allows keratinocytes to enter a protective alternative differentiation process rather than die massively after stress.

Curcumin Protects against UVB-Induced Skin Cancers in SKH-1 Hairless Mouse: Analysis of Early Molecular Markers in Carcinogenesis

Directory of Open Access Journals (Sweden)

Kuen-Daw Tsai

2012-01-01

Full Text Available Curcumin (CUR has been shown to possess a preventive effect against various cancers and interfere with multiple-cell signaling pathways. We evaluated the protective effects of CUR in regression of UVB-induced skin tumor formation in SKH-1 hairless mice and its underlying early molecular biomarkers associated with carcinogenesis. Mice irradiated with UVB at 180 mJ/cm2 twice per week elicited 100% tumor incidence at 20 weeks. Topical application of CUR prior to UVB irradiation caused delay in tumor appearance, multiplicity, and size. Topical application of CUR prior to and immediately after a single UVB irradiation (180 mJ/cm2 resulted in a significant decrease in UVB-induced thymine dimer-positive cells, expression of proliferative cell nuclear antigen (PCNA, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, and apoptotic sunburn cells together with an increase in p53 and p21/Cip1-positive cell population in epidermis. Simultaneously, CUR also significantly inhibited NF-κB, cyclooxygenase-2 (COX-2, prostaglandin E2 (PGE2, and nitric oxide (NO levels. The results suggest that the protective effect of CUR against photocarcinogenesis is accompanied by downregulation of cell proliferative controls, involving thymine dimer, PCNA, apoptosis, transcription factors NF-κB, and of inflammatory responses involving COX-2, PGE2, and NO, while upregulation of p53 and p21/Cip1 to prevent DNA damage and facilitate DNA repair.

The response of antioxidant systems in Nostoc sphaeroides against UV-B radiation and the protective effects of exogenous antioxidants

Science.gov (United States)

Wang, Gaohong; Hu, Chunxiang; Li, Dunhai; Zhang, Delu; Li, Xiaoyan; Chen, Kun; Liu, Yongding

UV radiation is one of many harmful factors found in space that are detrimental to organisms on earth in space exploration. In the present work, we examined the role of antioxidant system in Nostoc sphaeroides Kütz (Cyanobacterium) and the effects of exogenously applied antioxidant molecules on its photosynthetic rate under UV-B radiation. It was found that UV-B radiation promoted the activity of antioxidant system to protect photosystem II (PSII) and exogenously applied antioxidant: sodium nitroprusside (SNP) and N-acetylcysteine (NAC) had an obvious protection on PSII activity under UV-B radiation. The activity of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), peroxidase (POD, EC 1.11.1.7) and content of MDA (malondialdehyde) and ASC (ascorbate) were improved by 0.5 mM and 1 mM SNP, but 0.1 mM SNP decreased the activity of antioxidant system. Addition of exogenous NAC decreased the activity of SOD, POD, CAT and the content MDA and ASC. In contrast, exogenously applied NAC increased GSH content. The results suggest that exogenous SNP and NAC may protect algae by different mechanisms: SNP may play double roles as both sources of reactive free radicals as well as ROS scavengers in mediating the protective role of PSII on algae under UV-B radiation. On the other hand, NAC functions as an antioxidant or precursor of glutathione, which could protect PSII directly from UV-B radiation.

UV-B Irradiation Changes Specifically the Secondary Metabolite Profile in Broccoli Sprouts: Induced Signaling Overlaps with Defense Response to Biotic Stressors

Science.gov (United States)

Mewis, Inga; Schreiner, Monika; Nguyen, Chau Nhi; Krumbein, Angelika; Ulrichs, Christian; Lohse, Marc; Zrenner, Rita

2012-01-01

Only a few environmental factors have such a pronounced effect on plant growth and development as ultraviolet light (UV). Concerns have arisen due to increased UV-B radiation reaching the Earth’s surface as a result of stratospheric ozone depletion. Ecologically relevant low to moderate UV-B doses (0.3–1 kJ m–2 d–1) were applied to sprouts of the important vegetable crop Brassica oleracea var. italica (broccoli), and eco-physiological responses such as accumulation of non-volatile secondary metabolites were related to transcriptional responses with Agilent One-Color Gene Expression Microarray analysis using the 2×204 k format Brassica microarray. UV-B radiation effects have usually been linked to increases in phenolic compounds. As expected, the flavonoids kaempferol and quercetin accumulated in broccoli sprouts (the aerial part of the seedlings) 24 h after UV-B treatment. A new finding is the specific UV-B-mediated induction of glucosinolates (GS), especially of 4-methylsulfinylbutyl GS and 4-methoxy-indol-3-ylmethyl GS, while carotenoids and Chl levels remained unaffected. Accumulation of defensive GS metabolites was accompanied by increased expression of genes associated with salicylate and jasmonic acid signaling defense pathways and up-regulation of genes responsive to fungal and bacterial pathogens. Concomitantly, plant pre-exposure to moderate UV-B doses had negative effects on the performance of the caterpillar Pieris brassicae (L.) and on the population growth of the aphid Myzus persicae (Sulzer). Moreover, insect-specific induction of GS in broccoli sprouts was affected by UV-B pre-treatment. PMID:22773681

UV-A enhanced growth and UV-B induced positive effects in the recovery of photochemical yield in Gracilaria lemaneiformis (Rhodophyta).

Science.gov (United States)

Xu, Juntian; Gao, Kunshan

2010-09-02

The effects of solar UV radiation (280-400 nm) on growth, quantum yield and pigmentation in Gracilaria lemaneiformis were investigated when the thalli were cultured under solar radiation with or without UV for a period of 15 days. Presence of UV-A (315-400 nm) enhanced the relative growth rate, while UV-B (218-315 nm) inhibited it. The positive effect of UV-A and negative effect of UV-B counteracted to result in an insignificant impact of UVR on growth. During the noon period, both UV-A and UV-B resulted in the decrease of maximum quantum yield (Fv/Fm), but UV-B aided in the recovery of the yield in the late afternoon, reflecting that UV-B might be used as a signal in photorepair processes. UV induced the accumulation of UV-absorbing compounds (UVAC) to defend against the harmful UVR. However, the accumulation of UVAC took a much longer time compared to that previously reported, which was probably due to the lower levels of solar radiation and water temperature in the early spring period. Unknown UV-absorbing compounds (UVAC), which peaked at 265 nm, probably the precursor of MAAs (UVAC(325)), accumulated under moderate levels of solar radiation and were transformed to MAAs under higher solar radiation. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Interaction of moderate UV-B exposure and temperature on the formation of structurally different flavonol glycosides and hydroxycinnamic acid derivatives in kale (Brassica oleracea var. sabellica).

Science.gov (United States)

Neugart, Susanne; Fiol, Michaela; Schreiner, Monika; Rohn, Sascha; Zrenner, Rita; Kroh, Lothar W; Krumbein, Angelika

2014-05-07

Kale has a high number of structurally different flavonol glycosides and hydroxycinnamic acid derivatives. In this study we investigated the interaction of moderate UV-B radiation and temperature on these compounds. Kale plants were grown at daily mean temperatures of 5 or 15 °C and were exposed to five subsequent daily doses (each 0.25 kJ m(-2) d(-1)) of moderate UV-B radiation at 1 d intervals. Of 20 phenolic compounds, 11 were influenced by an interaction of UV-B radiation and temperature, e.g., monoacylated quercetin glycosides. Concomitantly, enhanced mRNA expression of flavonol 3'- hydroxylase showed an interaction of UV-B and temperature, highest at 0.75 kJ m(-2) and 15 °C. Kaempferol glycosides responded diversely and dependent on, e.g., the hydroxycinnamic acid residue. Compounds containing a catechol structure seem to be favored in the response to UV-B. Taken together, subsequent exposure to moderate UV-B radiation is a successful tool for enhancing the flavonoid profile of plants, and temperature should be considered.

Long-term structural canopy changes sustain net photosynthesis per ground area in high arctic Vaccinium uliginosum exposed to changes in near-ambient UV-B levels.

Science.gov (United States)

Boesgaard, Kristine S; Albert, Kristian R; Ro-Poulsen, Helge; Michelsen, Anders; Mikkelsen, Teis N; Schmidt, Niels M

2012-08-01

Full recovery of the ozone layer is not expected for several decades and consequently, the incoming level of solar ultraviolet-B (UV-B) will only slowly be reduced. Therefore to investigate the structural and photosynthetic responses to changes in solar UV-B we conducted a 5-year UV-B exclusion study in high arctic Greenland. During the growing season, the gas exchange (H₂O and CO₂) and chlorophyll-a fluorescence were measured in Vaccinium uliginosum. The leaf dry weight, carbon, nitrogen, stable carbon isotope ratio, chlorophyll and carotenoid content were determined from a late season harvest. The net photosynthesis per leaf area was on average 22% higher in 61% reduced UV-B treatment across the season, but per ground area photosynthesis was unchanged. The leaf level increase in photosynthesis was accompanied by increased leaf nitrogen, higher stomatal conductance and F(v)/F(m). There was no change in total leaf biomass, but reduction in total leaf area caused a pronounced reduction of specific leaf area and leaf area index in reduced UV-B. This demonstrates the structural changes to counterbalance the reduced plant carbon uptake seen per leaf area in ambient UV-B as the resulting plant carbon uptake per ground area was not affected. Thus, our understanding of long-term responses to UV-B reduction must take into account both leaf level processes as well as structural changes to understand the apparent robustness of plant carbon uptake per ground area. In this perspective, V. uliginosum seems able to adjust plant carbon uptake to the present amount of solar UV-B radiation in the High Arctic. Copyright © Physiologia Plantarum 2011.

Photonic activation of plasminogen induced by low dose UVB.

Directory of Open Access Journals (Sweden)

Manuel Correia

Full Text Available Activation of plasminogen to its active form plasmin is essential for several key mechanisms, including the dissolution of blood clots. Activation occurs naturally via enzymatic proteolysis. We report that activation can be achieved with 280 nm light. A 2.6 fold increase in proteolytic activity was observed after 10 min illumination of human plasminogen. Irradiance levels used are in the same order of magnitude of the UVB solar irradiance. Activation is correlated with light induced disruption of disulphide bridges upon UVB excitation of the aromatic residues and with the formation of photochemical products, e.g. dityrosine and N-formylkynurenine. Most of the protein fold is maintained after 10 min illumination since no major changes are observed in the near-UV CD spectrum. Far-UV CD shows loss of secondary structure after illumination (33.4% signal loss at 206 nm. Thermal unfolding CD studies show that plasminogen retains a native like cooperative transition at ~70 ºC after UV-illumination. We propose that UVB activation of plasminogen occurs upon photo-cleavage of a functional allosteric disulphide bond, Cys737-Cys765, located in the catalytic domain and in van der Waals contact with Trp761 (4.3 Å. Such proximity makes its disruption very likely, which may occur upon electron transfer from excited Trp761. Reduction of Cys737-Cys765 will result in likely conformational changes in the catalytic site. Molecular dynamics simulations reveal that reduction of Cys737-Cys765 in plasminogen leads to an increase of the fluctuations of loop 760-765, the S1-entrance frame located close to the active site. These fluctuations affect the range of solvent exposure of the catalytic triad, particularly of Asp646 and Ser74, which acquire an exposure profile similar to the values in plasmin. The presented photonic mechanism of plasminogen activation has the potential to be used in clinical applications, possibly together with other enzymatic treatments for the

Evaluation of the role of damage to photosystem II in the inhibition of CO2 assimilation in pea leaves on exposure to UV-B radiation

International Nuclear Information System (INIS)

Nogues, S.; Baker, N.R.

1995-01-01

Mature pea (Pisum sativum L., cv. Meteor) leaves were exposed to two levels of UV-B radiation, with and without supplementary UV-C radiation, during 15 h photoperiods. Simultaneous measurements of CO 2 assimilation and modulated chlorophyll fluorescence parameters demonstrated that irradiation with UV-B resulted in decreases in CO 2 assimilation that are not accompanied by decreases in the maximum quantum efficiency of photosystem II (PSII) primary photochemistry. Increased exposure to UV-B resulted in a further loss of CO 2 assimilation and decreases in the maximum quantum efficiency of PSII primary photochemistry, which were accompanied by a loss of the capacity of thylakoids isolated from the leaves to bind atrazine, thus demonstrating that photodamage to PSII reaction centres had occurred. Addition of UV-C to the UV-B treatments increased markedly the rate of inhibition of photosynthesis, but the relationships between CO 2 assimilation and PSII characteristics remained the same, indicating that UV-B and UV-C inhibit leaf photosynthesis by a similar mechanism. It is concluded that PSII is not the primary target site involved in the onset of the inhibition of photosynthesis in pea leaves induced by irradiation with UV-B. (author)

Photobiological implications of melanin photoprotection after UVB-induced tanning of human skin but not UVA-induced tanning.

Science.gov (United States)

Coelho, Sergio G; Yin, Lanlan; Smuda, Christoph; Mahns, Andre; Kolbe, Ludger; Hearing, Vincent J

2015-03-01

Repetitive suberythemal UVA and/or UVB exposures were used to generate comparable UV-induced tans in human skin over the course of 2 weeks. To evaluate the potential photoprotective values of those UVA- and/or UVB- induced tans and to avoid the confounding issue of residual UV-induced DNA damage, we waited 1 week before challenging those areas with a 1.5 MED of UVA+UVB after which we measure DNA damage. The results show that the type of UV used to induce skin pigmentation affects the redistribution of melanin in the skin and/or de novo melanin synthesis. The UVA-induced tans failed to even provide a minimal SPF of 1.5, which suggests that producing a tan with UVA-rich sunlamps prior to a holiday or vacation is completely counterproductive. Published 2014. This article is a US Government work and is in the public domain in the USA.

Effects of silicon application on diurnal variations of physiological properties of rice leaves of plants at the heading stage under elevated UV-B radiation

Science.gov (United States)

Lou, Yun-sheng; Wu, Lei; Lixuan, Ren; Meng, Yan; Shidi, Zhao; Huaiwei, Zhu; Yiwei, Zhang

2016-02-01

We investigated the effects of silicon (Si) application on diurnal variations of photosynthetic and transpiration physiological parameters in potted rice ( Oryza sativa L. cv Nanjing 45) at the heading stage. The plants were subjected to two UV-B radiation levels, i.e., reference UV-B (A, ambient, 12.0 kJ m-2 day-1) and elevated UV-B radiation (E, a 20 % higher dose of UV-B than the reference, 14.4 kJ m-2 day-1), and four Si application levels, i.e., Si0 (no silicon supplementation, 0 kg SiO2 ha-1), Si1 (sodium silicate, 100 kg SiO2 ha-1), Si2 (sodium silicate, 200 kg SiO2 ha-1), and Si3 (slag silicon fertilizer, 200 kg SiO2 ha-1). Compared with the reference, elevated UV-B radiation decreased the diurnal mean values of the net photosynthetic rate ( Pn), intercellular carbon dioxide (CO2) concentration ( Ci), transpiration rate ( Tr), stomatal conductivity ( Gs), and water use efficiency (WUE) by 11.3, 5.5, 10.4, 20.3, and 6.3 %, respectively, in plants not supplemented with silicon (Si0), and decreased the above parameters by 3.8-5.5, 0.7-4.8, 4.0-8.7, 7.4-20.2, and 0.7-5.9 %, respectively, in plants treated with silicon (Si1, Si2, and Si3), indicating that silicon application mitigates the negative effects of elevated UV-B radiation. Under elevated UV-B radiation, silicon application (Si1, Si2, and Si3) increased the diurnal mean values of Pn, Ci, Gs, and WUE by 16.9-28.0, 3.5-14.3, 16.8-38.7, and 29.0-51.2 %, respectively, but decreased Tr by 1.9-10.8 %, compared with plants not treated with silicon (E+Si0), indicating that silicon application mitigates the negative effects of elevated UV-B radiation by significantly increasing the P n, C i, G s, and WUE and decreasing the T r of rice. Evident differences existed in mitigating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among different silicon application treatments, exhibiting as Si3>Si2>Si1>Si0. In addition to recycling steel industrial wastes, the

Effects of silicon application on diurnal variations of physiological properties of rice leaves of plants at the heading stage under elevated UV-B radiation.

Science.gov (United States)

Lou, Yun-sheng; Wu, Lei; Lixuan, Ren; Meng, Yan; Shidi, Zhao; Huaiwei, Zhu; Yiwei, Zhang

2016-02-01

We investigated the effects of silicon (Si) application on diurnal variations of photosynthetic and transpiration physiological parameters in potted rice (Oryza sativa L. cv Nanjing 45) at the heading stage. The plants were subjected to two UV-B radiation levels, i.e., reference UV-B (A, ambient, 12.0 kJ m(-2) day(-1)) and elevated UV-B radiation (E, a 20% higher dose of UV-B than the reference, 14.4 kJ m(-2) day(-1)), and four Si application levels, i.e., Si0 (no silicon supplementation, 0 kg SiO2 ha(-1)), Si1 (sodium silicate, 100 kg SiO2 ha(-1)), Si2 (sodium silicate, 200 kg SiO2 ha(-1)), and Si3 (slag silicon fertilizer, 200 kg SiO2 ha(-1)). Compared with the reference, elevated UV-B radiation decreased the diurnal mean values of the net photosynthetic rate (Pn), intercellular carbon dioxide (CO2) concentration (Ci), transpiration rate (Tr), stomatal conductivity (Gs), and water use efficiency (WUE) by 11.3, 5.5, 10.4, 20.3, and 6.3%, respectively, in plants not supplemented with silicon (Si0), and decreased the above parameters by 3.8-5.5, 0.7-4.8, 4.0-8.7, 7.4-20.2, and 0.7-5.9%, respectively, in plants treated with silicon (Si1, Si2, and Si3), indicating that silicon application mitigates the negative effects of elevated UV-B radiation. Under elevated UV-B radiation, silicon application (Si1, Si2, and Si3) increased the diurnal mean values of Pn, Ci, Gs, and WUE by 16.9-28.0, 3.5-14.3, 16.8-38.7, and 29.0-51.2%, respectively, but decreased Tr by 1.9-10.8%, compared with plants not treated with silicon (E+Si0), indicating that silicon application mitigates the negative effects of elevated UV-B radiation by significantly increasing the P n, C i, G s, and WUE and decreasing the T r of rice. Evident differences existed in mitigating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among different silicon application treatments, exhibiting as Si3>Si2>Si1>Si0. In addition to recycling steel industrial wastes, the

Improvement effect of gamma-irradiated complex leaf extract of date plum, persimmon and mulberry on UVB-induced skin damage

Energy Technology Data Exchange (ETDEWEB)

Choi, Ji Won; Cho, Byoung Ok; Che, Denis Nchang; Shin, Jae Young; Fang, Chong Zhou; Jang, Seon Il [Jeonju University, Jeonju (Korea, Republic of)

2016-11-15

This study was conducted to evaluate the improvement effect of gamma-irradiated complex leaf extract of Date Plum, Persimmon and Mulberry (γ-DPME) on UVB induced skin damage. The samples were gamma irradiated at doses of 10 kGy. γ-DPME treatment tended to decrease UVB-induced immune cell infiltration and erthyderma index than the groups treated with non-gamma-irradiated DPME (n-DPME) and L-ascobic acid (AA). In addition, γ-DPME treatment significantly decreased skin thickness, melanin index and mast cell infiltration in UVB-irradiated skin. Moreover, γ-DPME treatment significantly decreased the compound 48/80-induced scratching behavior and immune cell infiltration than n-DPME group. These results show that gamma irradiation can be used to increase the physiological activities of DPME.

Comparison of UVB and UVC irradiation disinfection efficacies on Pseudomonas Aeruginosa biofilm

DEFF Research Database (Denmark)

Argyraki, Aikaterini; Markvart, M.; Nielsen, Anne

2016-01-01

skin, soft tissue, lungs, kidney and urinary tract infections. Moreover, it can be found on and in medical equipment causing often cross infections in hospitals. The objective of this study was to test the efficiency, of two different light-based disinfection treatments, namely UVB and UVC irradiation......, on P. aeruginosa biofilms at different growth stages. In our experiments a new type of UV light emitting diodes (LEDs) were used to deliver UV irradiation on the biofilms, in the UVB (296nm) and UVC (266nm) region. The killing rate was studied as a function of dose for 24h grown biofilms. The dose......Disinfection routines are important in all clinical applications. The uprising problem of antibiotic resistance has driven major research efforts towards alternative disinfection approaches, involving light-based solutions. Pseudomonas aeruginosa (P. aeruginosa) is a common bacterium that can cause...

Quercetin oxidation by horseradish peroxidase: The effect of UV-B irradiation

Directory of Open Access Journals (Sweden)

Savić Saša R.

2013-01-01

Full Text Available Horseradish peroxidase (HRP, a highly-investigated member of the peroxidase family has been known, among many other biological activities, to catalyze the oxidation of flavonoids and phenolic substrates overall, including quercetin. On the other hand, quercetin is very well known for its antioxidant activities, which in the case of UV external radiation is exibited partly in a preventive manner since it is an excellent UV-absorber. Therefore the aim of this investigation is to study quercetin oxidation by HRP in phosphate buffer under the conditions of UV-stress, i.e. continuous, prolonged UV-B irradiation. The results show that while UV-B irradiation affects the activity of HRP, and the overal rate of quercetin oxidation by HRP, it probably has very little effect on it for longer UV-B-irradiation periods (>30 min. [Acknowledgements. This work was supported by the Ministry of Education and Science of the Republic of Serbia under Project No.TR-34012 and OI-172044

Pharmacological activities of an eye drop containing Matricaria chamomilla and Euphrasia officinalis extracts in UVB-induced oxidative stress and inflammation of human corneal cells.

Science.gov (United States)

Bigagli, Elisabetta; Cinci, Lorenzo; D'Ambrosio, Mario; Luceri, Cristina

2017-08-01

Ultraviolet B (UVB) exposure is a risk factor for corneal damage resulting in oxidative stress, inflammation and cell death. The aim of this study was to investigate the potential protective effects of a commercial eye drop (Dacriovis™) containing Matricaria chamomilla and Euphrasia officinalis extracts on human corneal epithelial cells (HCEC-12) against UVB radiation-induced oxidative stress and inflammation as well as the underlying mechanisms. The antioxidant potential of the eye drops was evaluated by measuring the ferric reducing antioxidant power and the total phenolic content by Folin-Ciocalteu reagent. HCEC-12 cells were exposed to UVB radiation and treated with the eye drops at various concentrations. Cell viability, wound healing assay, reactive oxygen species (ROS) levels, protein and lipid oxidative damage and COX-2, IL-1β, iNOS, SOD-2, HO-1 and GSS gene expression, were assessed. Eye drops were able to protect corneal epithelial cells from UVB-induced cell death and ameliorated the wound healing; the eye drops exhibited a strong antioxidant activity, decreasing ROS levels and protein and lipid oxidative damage. Eye drops also exerted anti-inflammatory activities by decreasing COX-2, IL-1β, iNOS expression, counteracted UVB-induced GSS and SOD-2 expression and restored HO-1 expression to control levels. These findings suggest that an eye drop containing Matricaria chamomilla and Euphrasia officinalis extracts exerts positive effects against UVB induced oxidative stress and inflammation and may be useful in protecting corneal epithelial cells from UVB exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

Intra- and interspecific differences of 10 barley and 10 tomato cultivars in response to short-time UV-B radiation: A study analysing thermoluminescence, fluorescence, gas-exchange and biochemical parameters

International Nuclear Information System (INIS)

Gilbert, Matthias; Poers, Yvonne; Grover, Kirsten; Weingart, Ilka; Skotnica, Jiri; Grimm, Bernhard; Seidlitz, Harald K.; Langebartels, Christian; Wilhelm, Christian

2009-01-01

The impact of UV-B radiation on 10 genotypically different barley and tomato cultivars was tested in a predictive study to screen for potentially UV-tolerant accessions and to analyze underlying mechanisms for UV-B sensitivity. Plant response was analyzed by measuring thermoluminescence, fluorescence, gas exchange and antioxidant status. Generally, barley cultivars proved to be much more sensitive against UV-B radiation than tomato cultivars. Statistical cluster analysis could resolve two barley groups with distinct differences in reaction patterns. The UV-B sensitive group showed a stronger loss in PSII photochemistry and a lower gas-exchange performance and regulation after UV-B radiation compared to the more tolerant group. The results indicate that photosynthetic light and dark reactions have to play optimally in concert to render plants more tolerant against UV-B radiation. Hence, measuring thermoluminescence/fluorescence and gas exchange in parallel will have much higher potential in identifying tolerant cultivars and will help to understand the underlying mechanisms. - Mechanisms of UV-B tolerance and sensitivity in crop plants.

Redox proteomic evaluation of oxidative modification and recovery in a 3D reconstituted human skin tissue model exposed to UVB.

Science.gov (United States)

Dyer, J M; Haines, S R; Thomas, A; Wang, W; Walls, R J; Clerens, S; Harland, D P

2017-04-01

Exposure to UV in humans resulting in sunburn triggers a complex series of events that are a mix of immediate and delayed damage mediation and healing. While studies on the effects of UV exposure on DNA damage and repair have been reported, changes in the oxidative modification of skin proteins are poorly understood at the molecular level, despite the important role played by structural proteins in skin tissue, and the effect of the integrity of these proteins on skin appearance and health. Proteomic molecular mapping of oxidation was here applied to try to enhance understanding of skin damage and recovery from oxidative damage and UVB exposure. A redox proteomic-based approach was applied to evaluating skin protein modification when exposed to varying doses of UVB after initial oxidative stress, via tracking changes in protein oxidation during the healing process in vitro using a full-thickness reconstituted human skin tissue model. Bioassays and structural evaluation confirmed that our cultured skin tissues underwent a normal physiological response to UVB exposure. A set of potential skin marker peptides was generated, for use in tracking skin protein oxidative modification. Exposure to UVB after thermal oxidative stress was found to result in higher levels of skin protein oxidation than a non-irradiated control for up to seven days after exposure. Recovery of the skin proteins from oxidative stress, as assessed by the overall protein oxidation levels, was found to be impaired by UVB exposure. Oxidative modification was largely observed in skin structural proteins. Exposure of skin proteins to UVB exacerbates oxidative damage to structural skin proteins, with higher exposure levels leading to increasingly impaired recovery from this damage. This has potential implications for the functional performance of the proteins and inter-related skin health and cosmetic appearance. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Effects of enhanced UVB on growth and yield of two Syrian crops, wheat (Triticum durum desf. var. horani) and broad beans (Vicia Faba L.) under field conditions

International Nuclear Information System (INIS)

Al-Oudat, M.; Baydoun, S.A.

1997-04-01

Wheat and broad beans were exposed, under field conditions, to a daily UVB of 20 % above the ambient UVB. The plant height, tiller number, number of flowers, spikletes, dry weight and leaf area in both species showed positive responses to UVB treatment. At harvest, the seeds weight of broad beans was virtually equal in exposed and unexposed plants. In wheat, seeds yield increased significantly by 15 %. In conclusion, broad beans can be considered as a tolerant cultivar to enhanced UVB, while wheat is more tolerant. (Author). 17 Tabs. 36 Refs

Fractional Er:YAG laser assisting topical betamethasone solution in combination with NB-UVB for resistant non-segmental vitiligo.

Science.gov (United States)

Yan, Ru; Yuan, Jinping; Chen, Hongqiang; Li, Yuan-Hong; Wu, Yan; Gao, Xing-Hua; Chen, Hong-Duo

2017-09-01

Resistant non-segmental vitiligo is difficult to be treated. Ablative erbium-YAG (Er:YAG) laser has been used in the treatment of vitiligo, but the ablation of entire epidermis frustrated the compliance of patients. The purpose of this study is to investigate the effects of fractional Er:YAG laser followed by topical betamethasone and narrow band ultraviolet B (NB-UVB) therapy in the treatment of resistant non-segmental vitiligo. The vitiligo lesions of each enrolled patient were divided into four treatment parts, which were all irradiated with NB-UVB. Three parts were, respectively, treated with low, medium, or high energy of Er:YAG laser, followed by topical betamethasone solution application. A control part was spared with laser treatment and topical betamethasone. The treatment period lasted 6 months. The efficacy was assessed by two blinded dermatologists. Treatment protocol with high energy of 1800 mJ/P of fractional Er:YAG laser followed by topical betamethasone solution and in combination with NB-UVB made 60% patients achieve marked to excellent improvement in white patches. The protocol with medium energy of 1200 mJ/P of laser assisted approximate 36% patients achieve such improvement. The two protocols, respectively, showed better efficacies than NB-UVB only protocol. However, fractional Er:YAG laser at low energy of 600 mJ/P did not provide such contributions to the treatment of vitiligo. The fractional Er:YAG laser in combination with topical betamethasone solution and NB-UVB was suitable for resistant non-segmental vitiligo. The energy of laser was preferred to be set at relatively high level.

Djulis (Chenopodium formosanum Koidz. Water Extract and Its Bioactive Components Ameliorate Dermal Damage in UVB-Irradiated Skin Models

Directory of Open Access Journals (Sweden)

Yong-Han Hong

2016-01-01

Full Text Available Dermal photoaging is a condition of skin suffering inappropriate ultraviolet (UV exposure and exerts inflammation, tissue alterations, redness, swelling, and uncomfortable feelings. Djulis (Chenopodium formosanum Koidz. is a cereal food and its antioxidant and pigment constituents may provide skin protection from photoaging, but it still lacks proved experiments. In this study, protective effects of djulis extract (CFE on UVB-irradiated skin were explored. The results showed that HaCaT cells with 150 μg/mL CFE treatment had higher survival and less production of interleukin- (IL- 6, matrix metalloprotease- (MMP- 1, and reactive oxygen species (ROS in UVB-irradiated conditions. Subsequently, in animal studies, mice supplemented with CFE (100 mg/kg BW were under UVB irradiation and had thinner epidermis and lower IL-6 levels in skin layer. These data demonstrate that bioactive compounds possessing the potency of antiphotoaging exist in CFE. Following that, we found rutin and chlorogenic acid (10–100 μM could significantly increase cell viability and decrease the production of IL-6 in UVB models. Additionally, djulis pigment-betanin has no effect of increasing cell viability in this study. Our findings suggest CFE can protect skin against UV-induced damage and this protection is mainly from contributions of rutin and chlorogenic acid.

Influence of low energy N+ ions pre-treatment on damage effects of UV-B irradiation on M1 rice

International Nuclear Information System (INIS)

Zhao Shuaipeng; Huang Qunce; Chen Xueneng

2011-01-01

The seedlings of rice (xindao18) were exposed to UV-B (10.08 kJ/(m 2 ·d 1 )) irradiation following the pretreatment with three different implantation dosages of low-energy N + ions. Changes in the levels of the superoxide (POD), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), glutathione (GSH) and soluble sugar were measured. The result showed that the UV-B irradiation on the seedlings of rice pretreated with low-energy ions implantation could lead to increase activities in POD and SOD, and the maximum appeared on the dose of 2.0 x 10 17 ions/cm 2 . Meanwhile, it made the content of GSH increased, and caused the activity of CAT and the content of MDA to be decreased. But there was no obvious change in soluble sugar. It was suggested that the rice pretreated by low energy ion implantation could enhance the antioxidation capacity and defensive ability when irradiated by UV-B, and the antioxidation system could be induced earlier than carbohydrate system. Therefore,the biological effects of UV-B irradiation on rice pretreated by low energy ion implantation were quite obvious. (authors)

Distinct UV-B and UV-A/blue light signal transduction pathways induce chalcone synthase gene expression in Arabidopsis cells

International Nuclear Information System (INIS)

Christie, J.M.; Jenkins, G.I.

1996-01-01

UV and blue light control the expression of flavonoid biosynthesis genes in a range of higher plants. To investigate the signal transduction processes involved in the induction of chalcone synthase (CHS) gene expression by UV-B and UV-A/blue light, we examined the, effects of specific agonists and inhibitors of known signaling components in mammalian systems in a photomixotrophic Arabidopsis cell suspension culture. CHS expression is induced specifically by these wavelengths in the cell culture, in a manner similar to that in mature Arabidopsis leaf tissue. Both the UV-B and UV-A/blue phototransduction processes involve calcium, although the elevation of cytosolic calcium is insufficient on its own to stimulate CHS expression. The UV-A/blue light induction of CHS expression does not appear to involve calmodulin, whereas the UV-B response does; this difference indicates that the signal transduction pathways are, at least in part, distinct. We provide evidence that both pathways involve reversible protein phosphorylation and require protein synthesis. The UV-B and UV-A/blue light signaling pathways are therefore different from the phytochrome signal transduction pathway regulating CHS expression in other species

The protective effects of fucosterol against skin damage in UVB-irradiated human dermal fibroblasts.

Science.gov (United States)

Hwang, Eunson; Park, Sang-Yong; Sun, Zheng-wang; Shin, Heon-Sub; Lee, Don-Gil; Yi, Tae Hoo

2014-06-01

Exposure to ultraviolet (UV) light causes matrix metalloproteinase (MMP) overexpression and extracellular matrix depletion, leading to skin photoaging. The activation of MMP is related to increased interlukin-6 (IL-6) and type I procollagen production, which is regulated by transforming growth factor-β1 (TGF-β1). Activator protein-1 (AP-1) activation induces MMP-1 production and reduces type I procollagen secretion. Fucosterol, which is extracted and purified from the brown algae Hizikia fusiformis, is a phytosterol. We assessed the effects of fucosterol on photodamage and investigated its molecular mechanism of action in UVB-irradiated normal human dermal fibroblasts by using enzyme-linked immunosorbent assay, Western blot analysis, and reverse transcription-polymerase chain reaction. Our results showed that fucosterol significantly decreased the UVB-induced expression of MMP-1, IL-6, p-c-Jun, and p-c-Fos. Additionally, fucosterol markedly increased the UVB-induced production of type I procollagen and TGF-β1. Our results indicate that fucosterol regulates MMP-1 and type I procollagen expression by modulating AP-1 and TGF-β1 signaling and that MMP-1 activation is correlated with IL-6. These data suggest that fucosterol is a promising botanical agent to protect against skin photodamage.

Specific racemization and isomerization of the aspartyl residue of αA-crystallin due to UV-B irradiation

International Nuclear Information System (INIS)

Fujii, Noriko; Momose, Yuko; Ishibasi, Yoshihiro; Uemura, Toshimasa; Takita, Masatoshi; Takehana, Makoto

1997-01-01

We have reported that the aspartyl (Asp)-151 residue in αA-crystallin in human eye lens was inverted to the D-isomer and isomerized to β-Asp residue with age. We report here that ultraviolet (UV)-B irradiation induces the racemization and isomerization of the Asp-151 residue of αA-crystallin from lenses of 6-week-old rats to form D-isomer and β-Asp residue. Simultaneous racemization and isomerization of the specific Asp residue indicate that the reaction proceeds via formation of a succinimide intermediate. This modification was not observed in UV-A irradiated and normal lenses. UV-B irradiation induced the racemization of only the Asp-151 residue and did not affect the other Asp residues in αA-crystallin. On the other hand, the high molecular weight fraction of the lens protein increased upon UV-B irradiation. Modification of the Asp residue would affect the three-dimensional packing array of the lens protein. (author)

Is pollen morphology of Salix polaris affected by enhanced UV-B irradiation? Results from a field experiment in high Arctic tundra

NARCIS (Netherlands)

Yeloff, Dan; Blokker, Peter; Boelen, Peter; Rozema, Jelte

2008-01-01

This study tested the hypothesis that the thickness of the pollen wall will increase in response to enhanced UV-B irradiation, by examining, the effect of enhanced UV-B irradiance on the pollen morphology of Sali-v polaris Wahlem. grown in a Field experiment on the Arctic tundra of Svalbard.

C/EBPα regulates CRL4Cdt2-mediated degradation of p21 in response to UVB-induced DNA damage to control the G1/S checkpoint

Science.gov (United States)

Hall, Jonathan R; Bereman, Michael S; Nepomuceno, Angelito I; Thompson, Elizabeth A; Muddiman, David C; Smart, Robert C

2014-01-01

The bZIP transcription factor, C/EBPα is highly inducible by UVB and other DNA damaging agents in keratinocytes. C/EBPα-deficient keratinocytes fail to undergo cell cycle arrest in G1 in response to UVB-induced DNA damage and mice lacking epidermal C/EBPα are highly susceptible to UVB-induced skin cancer. The mechanism through which C/EBPα regulates the cell cycle checkpoint in response to DNA damage is unknown. Here we report untreated C/EBPα-deficient keratinocytes have normal levels of the cyclin-dependent kinase inhibitor, p21, however, UVB-treated C/EBPα-deficient keratinocytes fail to up-regulate nuclear p21 protein levels despite normal up-regulation of Cdkn1a mRNA levels. UVB-treated C/EBPα-deficient keratinocytes displayed a 4-fold decrease in nuclear p21 protein half-life due to the increased proteasomal degradation of p21 via the E3 ubiquitin ligase CRL4Cdt2. Cdt2 is the substrate recognition subunit of CRL4Cdt2 and Cdt2 mRNA and protein levels were up-regulated in UVB-treated C/EBPα-deficient keratinocytes. Knockdown of Cdt2 restored p21 protein levels in UVB-treated C/EBPα-deficient keratinocytes. Lastly, the failure to accumulate p21 in response to UVB in C/EBPα-deficient keratinocytes resulted in decreased p21 interactions with critical cell cycle regulatory proteins, increased CDK2 activity, and inappropriate entry into S-phase. These findings reveal C/EBPα regulates G1/S cell cycle arrest in response to DNA damage via the control of CRL4Cdt2 mediated degradation of p21. PMID:25483090

“sacherklärungen” in biblischen texten – vorkommen und bedeutung ...

African Journals Online (AJOL)

Konzepten von Andrea Frank (University of South Africa, Pretoria 2008), auf die .... water', or better 'many waters', there, for in this locality there are seven springs .... der Begegnung Jesu mit einer samaritanischen Frau am Brunnen in Sychar.

Induction of wound-periderm-like tissue in Kalanchoe pinnata (Lam.) Pers. (Crassulaceae) leaves as a defence response to high UV-B radiation levels.

Science.gov (United States)

Nascimento, Luana Beatriz dos Santos; Moreira, Nattacha dos Santos; Leal-Costa, Marcos Vinícius; Costa, Sônia Soares; Tavares, Eliana Schwartz

2015-10-01

UV-B radiation can be stressful for plants and cause morphological and biochemical changes. Kalanchoe pinnata is a CAM leaf-succulent species distributed in hot and dry regions, and is rich in flavonoids, which are considered to be protective against UV-B radiation. This study aims to verify if K. pinnata has morphological or anatomical responses as a strategy in response to high UV-B levels. Kalanchoe pinnata plants of the same age were grown under white light (control) or white light plus supplemental UV-B radiation (5 h d(-1)). The plants were treated with the same photoperiod, photosynthetically active radiation, temperature and daily watering system. Fragments of the middle third of the leaf blade and petiole were dehydrated and then embedded in historesin and sectioned in a rotary microtome. Sections were stained with toluidine blue O and mounted in Entellan®. Microchemical analyses by optical microscopy were performed on fresh material with Sudan III, Sudan IV and phloroglucinol, and analysed using fluorescence microscopy. Supplemental UV-B radiation caused leaf curling and the formation of brown areas on the leaves. These brown areas developed into a protective tissue on the adaxial side of the leaf, but only in directly exposed regions. Anatomically, this protective tissue was similar to a wound-periderm, with outer layer cell walls impregnated with suberin and lignin. This is the first report of wound-periderm formation in leaves in response to UV-B radiation. This protective tissue could be important for the survival of the species in desert regions under high UV-B stress conditions. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The effect of chronic low-dose UVB radiation on Langerhans cells, sunburn cells, urocanic acid isomers, contact hypersensitivity and serum immunoglobulins in mice

International Nuclear Information System (INIS)

El-Ghorr, A.A.; Norval, M.; Lappin, M.B.

1995-01-01

C3H mice were irradiated three times a week for up to 6 weeks with either 500 J/m 2 or 1000 J/m 2 broadband UVB (270-350 nm) or 3000 J/m 2 narrowband UVB (311-312 nm; TL01 source). Each dose was suberythemal to the mouse strain used. The number of Langerhans cells (LC) in the epidermis was reduced by over 50% after 2 weeks of irradiation with the UVB source and by 20% following TL01 irradiation. Continued irradiation for up to 6 weeks resulted in no further decrease in LC numbers in the case of the UVB source but a steady decline to 40% in the case of the TL01 source. Sunburn cells were detected following irradiation with both sources but the numbers were very low in comparison with acute exposure. Ultraviolet-B exposure resulted in doubling of the thickness of the epidermis throughout the 6 weeks of irradiation while TL01 exposure did not alter epidermal thickness. Conversion of trans- to cis-urocanic acid (UCA) was observed with both UVB and TL01 sources. The percentage of cis-UCA started to return to normal after 4 weeks of TL01 exposure despite continued irradiation. As observed following a single exposure, the contact hypersensitivity (CH) response was significantly reduced following 6 weeks of UVB irradiation but was unaffected by TL01 exposure, indicating no correlation between cis-UCA levels and CH response. (author)

The protective effects of piceatannol from passion fruit (Passiflora edulis) seeds in UVB-irradiated keratinocytes.

Science.gov (United States)

Maruki-Uchida, Hiroko; Kurita, Ikuko; Sugiyama, Kenkichi; Sai, Masahiko; Maeda, Kazuhisa; Ito, Tatsuhiko

2013-01-01

The use of naturally occurring botanicals with substantial antioxidant activity to prevent photoageing is receiving increasing attention. We have previously identified piceatannol and scirpusin B, which is a dimer of piceatannol, as strong antioxidants that are present in passion fruit (Passiflora edulis) seeds. In the present study, the effects of passion fruit seed extract, piceatannol, and scirpusin B on human keratinocytes were investigated. The passion fruit seed extract and piceatannol upregulated the glutathione (GSH) levels in keratinocytes in a dose-dependent manner, indicating that piceatannol is an active component of the passion fruit seed extract in keratinocytes. The pretreatment with piceatannol also suppressed the UVB-induced generation of reactive oxygen species (ROS) in the keratinocytes. In addition, the transfer of the medium from the UVB-irradiated keratinocytes to non-irradiated fibroblasts enhanced matrix-metalloproteinase (MMP)-1 activity, and this MMP-1 induction was reduced when the keratinocytes were pretreated with piceatannol. These results suggest that piceatannol attenuates the UVB-induced activity of MMP-1 along with a reduction of ROS generation in keratinocytes. Thus, piceatannol and passion fruit seed extract containing high amounts of piceatannol are potential anti-photoageing cosmetic ingredients.

Long-term effects of elevated ozone and UV-B radiation on vegetation and methane dynamics in northern peatland ecosystems

Energy Technology Data Exchange (ETDEWEB)

Morsky, S.K.

2012-06-15

In the stratosphere, ozone (O{sub 3}) forms an effective barrier against high energy ultraviolet radiation (UV), which is harmful to living cells. Despite the stratospheric O{sub 3} layer recovering due to international agreements, seasonal O{sub 3} depletion periods with high UV-B levels, may still occur, especially in the Polar regions. In the troposphere, O{sub 3} is a significant greenhouse gas contributing to global warming and also causing oxidative stress to animal- and plant cells. Global tropospheric O{sub 3} concentration has approximately doubled during the last century and the same trend is expected to continue. Northern peatlands are sinks of atmospheric carbon dioxide (CO{sub 2}) and sources of the powerful greenhouse gas methane (CH{sub 4}). Two multi-year open-field experiments were conducted to study the effects of elevated O{sub 3} concentration and UV-B radiation on peatland vegetation and CH{sub 4} dynamics in Finland. Peatland microcosms were used in the O{sub 3} experiment and the UV-B exposure study was conducted on a natural fen. Elevated O{sub 3} concentration significantly increased leaf cross-sections and the total number of Eriophorum vaginatum leaves towards the end of the experiment, but did not affect relative length growth, stomatal density or volume of aerenchymatous tissue of leaves. Elevated O{sub 3} did not affect relative length growth of Sphagnum papillosum shoots either. Concentrations of chlorophylls or carotenoids in E. vaginatum leaves or in S. papillosum shoots were not changed under elevated O{sub 3}. During the first growing season, elevated O{sub 3} concentration decreased methanol-extractable, UV-absorbing compounds in E. vaginatum leaves. Elevated O{sub 3} increased concentrations of organic acids and microbial biomass (estimated by phospholipid fatty acid biomarkers) in peat during the third growing season. In the first growing season net CH{sub 4} emission was temporarily decreased by elevated O{sub 3} concentration

Caffeine decreases phospho-Chk1 (Ser317) and increases mitotic cells with cyclin B1 and caspase 3 in tumors from UVB-treated mice.

Science.gov (United States)

Lu, Yao-Ping; Lou, You-Rong; Peng, Qing-Yun; Nghiem, Paul; Conney, Allan H

2011-07-01

Oral administration of caffeine to mice inhibits UVB-induced carcinogenesis, and these results are paralleled by epidemiology studies indicating that caffeinated coffee and tea intake (but not decaffeinated beverage intake) is associated with decreased incidence of nonmelanoma skin cancer. Topical applications of caffeine to the skin of SKH-1 mice that had previously been treated with UVB inhibited subsequent skin tumor development and stimulated apoptosis in tumors but not in nontumor areas of the epidermis. This study sought to determine the basis of these differential effects on tumor versus nontumor sites that can be induced by caffeine, long after all UVB treatment has ceased. The activation status of the ATR/Chk1 pathway in UVB-induced tumors and uninvolved skin was determined by quantitating phospho-Chk1 (Ser317) and induction of lethal mitosis in vivo in the presence and absence of topical caffeine treatment. In the absence of caffeine, we found that UVB-induced tumors often had islands of phospho-Chk1 (Ser317) staining cells that were not present in nontumor areas of the epidermis. Treatment of mice with topical caffeine significantly diminished phospho-Chk1 (Ser317) staining and increased the number of mitotic cells that expressed cyclin B1 and caspase 3 in tumors, consistent with caffeine-induced lethal mitosis selectively in tumors. We hypothesize that compared with adjacent uninvolved skin, UVB-induced skin tumors have elevated activation of, and dependence on, the ATR/Chk1 pathway long after UVB exposure has ceased and that caffeine can induce apoptosis selectively in tumors by inhibiting this pathway and promoting lethal mitosis.

Beneficial effects of enhanced UV-B radiation under field conditions: improvement of needle water relations and survival capacity of Pinus pinea L. seedlings during the dry Mediterranean summer

International Nuclear Information System (INIS)

Manetas, Y.; Petropoulou, Y.; Stamatakis, K.; Nikolopoulos, D.; Levizou, E.; Psaras, G.; Karabourniotis, G.

1997-01-01

The possible mechanism(s) by which supplemental UV-B radiation alleviates the adverse effects of summer drought in Mediterranean pines (Petropoulou et al. 1995) were investigated with seedlings of Pinus pinea. Plants received ambient or ambient plus supplemental UV-B radiation (biologically equivalent to a 15% ozone depletion over Patras, 38.3° N, 29.1° E) and natural precipitation or additional irrigation. Treatments started on 1 February, 1994 and lasted up to the end of the dry period (29 September). In well-watered plants, UV-B radiation had no influence on photosystem II photochemical efficiency and biomass accumulation. Water stressed plants suffered from needle loss and reduced photosystem II photochemical efficiency during the summer. These symptoms, however, were less pronounced in plants receiving supplemental UV-B radiation, resulting in higher total biomass at plant harvest. Laboratory tests showed that enhanced UV-B radiation did not improve the tolerance of photosystem II against drought, high light, high temperature and oxidative stress. Enhanced UV-B radiation, however, improved the water economy of water stressed plants, as judged by measurements of needle relative water content. In addition, it caused an almost two-fold increase of cuticle thickness. No such UV-B radiation effects were observed in well-watered pines. The results indicate that the combination of water stress and UV-B radiation may trigger specific responses, enabling the plants to avoid excessive water loss and, thereby, maintain a more efficient photosynthetic apparatus during the summer. The extent of this apparently positive UV-B radiation effect would depend on the amount of summer precipitation. Abbreviations: DW – dry weight, F v /F m – ratio of variable to maximum fluorescence, A 300 – absorbance at 300 nm, PAR – photosynthetically active radiation, PS II – photosystem II, RWC – relative water content, TCA – trichloroacetic acid, UV-B BE – biologically

Responses of secondary chemicals in sugar maple (Acer saccharum) seedlings to UV-B, springtime warming and nitrogen additions

Energy Technology Data Exchange (ETDEWEB)

Sager, E.P.S.; Hutchinson, T.C. [Trent Univ., Peterborough, ON (Canada). Environmental Studies

2006-10-15

Elevated UV-B radiation due to climatic change and ozone depletion may represent a significant springtime environmental stressor to germinating seedlings in temperate forest regions. This study aimed to determine the effects of UV-B, nitrogen (N) fertilization and climate warming on the concentrations of base cations and secondary metabolites in the foliage of sugar maple seedlings growing in acid or alkaline soils. The influence of measured flavonoids and phenolics on herbivore activity was examined, as well as the relationship between foliar concentrations of calcium (Ca); manganese (Mn); and N and the production of phenolic and flavonoid compounds. Experimental plots were established in mature hardwood forests in alkaline and acid soil locations in Bobcaygeon and Haliburton, Ontario. Pentagonal open-top chambers were used to lengthen the growing season and simulate an earlier spring. Ammonium nitrate was applied at a rate comparable with an additional deposition of 5 g N per m per year. Fertilizer was applied on 3 separate occasions. Ambient UV-B radiation was screened out with Mylar D polyester film. Sites, treatments and time of sampling had complex effects on foliar elemental chemistry, production of secondary compounds and herbivory. Foliar concentrations of individual phenols were higher in seedlings in the UV-B exclusion treatments. At both sites, removal of ambient UV-B led to increases in flavonoids and chlorogenic acid, and reduced herbivore activity. At Haliburton, ammonium nitrate fertilization led to further increases in foliar Mn. Nitrogen additions led to decreases in the concentrations of some flavonoids at both sites. It was concluded that the composition of the forest soil governs the response of seedlings when they are exposed to abiotic stressors. 63 refs., 5 tabs., 8 figs.

UVB-induced epidermal hyperproliferation is modified by a single, topical treatment with a mitosis inhibitory epidermal pentapeptide

International Nuclear Information System (INIS)

Olsen, W.M.; Elgjo, K.

1990-01-01

A single application of a water-miscible cream base containing the recently identified mitosis inhibitory epidermal pentapeptide pyroGlu-Glu-Asp-Ser-GlyOH (EPP) to hairless mouse skin is followed by a long-lasting period of reduced epidermal cell proliferation. To examine if a similar growth inhibition could be achieved in stimulated and rapidly proliferating epidermis, EPP was applied at two different concentrations, 0.005 or 0.02%, to hairless mouse skin immediately after exposure of the left flank to an erythemic dose of ultraviolet B light (UVB). This dose of UVB alone induces a sustained period of rapid epidermal cell proliferation, starting at about 18 h after the irradiation. Epidermal cell proliferation was followed from 18 to 54 h (0.005% cream) or from 18 to 30 h (0.02% cream) after the treatment by estimating the rate of G2-M cell flux (the mitotic rate) by means of Colcemid, and epidermal DNA synthesis by counting labeled cells after pulse-labeling with 3H-thymidine. The unirradiated side of the mice was used as reference. The results showed that topical treatment with a 0.02% EPP cream partially inhibited UVB-induced epidermal hyperproliferation, while the 0.005% EPP cream inhibited as well as stimulated the UVB-induced hyperproliferation. Thus, EPP is effective even in rapidly proliferating epidermal cell populations, but the outcome is obviously dose-dependent in this test system

Physiological and growth responses of two African species, Acacia karroo and Themeda triandra, to combined increases in CO2 and UV-B radiation

International Nuclear Information System (INIS)

Wand, S.J.E.; Midgley, G.F.; Musil, C.F.

1996-01-01

The interactive effects of increased carbon dioxide (CO 2 ) concentration and ultraviolet-B (UV-B, 280–320 nm) radiation on Acacia karroo Hayne, a C 3 tree, and Themeda triandra Forsk., a C 4 grass, were investigated. We tested the hypothesis that A. karroo would show greater CO 2 -induced growth stimulation than T. triandra, which would partially explain current encroachment of A. karroo into C4 grasslands, but that increased UV-B could mitigate this advantage. Seedlings were grown in open-top chambers in a greenhouse in ambient (360 μmol mol -1 ) and elevated (650 μmol mol-1) CO 2 , combined with ambient (1.56 to 8.66 kJ m -2 day -1 ) or increased (2.22 to 11.93 kJ m -2 day -1 ) biologically effective (weighted) UV-B irradiances. After 30 weeks, elevated CO 2 had no effect on biomass of A. karroo, despite increased net CO 2 assimilation rates. Interaction between UV-B and CO 2 on stomatal conductance was found, with conductances decreasing only where elevated CO 2 and UV-B were supplied separately. Increases in water use efficiencies, foliar starch concentrations, root nodule numbers and total nodule mass were measured in elevated CO 2 . Elevated UV-B caused only an increase in foliar carbon concentrations. In T. triandra, net CO 2 assimilation rates were unaffected in elevated CO 2 , but stomatal conductances and foliar nitrogen concentrations decreased, and water use efficiencies increased. Biomass of all vegetative fractions, particularly leaf sheaths, was increased in elevated CO 2 . and was accompanied by increased leaf blade lengths and individual leaf and leaf sheath masses. However, tiller numbers were reduced in elevated CO 2 . Significantly moderating effects of elevated UV-B were apparent only in individual masses of leaf blades and sheaths, and in total sheath and shoot biomass. The direct CO 2 -induced growth responses of the species therefore do not support the hypothesis of CO 2 -driven woody encroachment of C 4 grasslands. Rather, differential

Effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme in bean (Phaseolus vulgaris L.) grown under different nitrogen conditions.

Science.gov (United States)

Pinto, M E; Casati, P; Hsu, T P; Ku, M S; Edwards, G E

1999-02-01

The effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme have been examined in different cultivars of Phaseolous vulgaris L. grown under 1 and 12 mM nitrogen. Low nitrogen nutrition reduces chlorophyll and soluble protein contents in the leaves and thus the photosynthesis rate and dry-matter accumulation. Chlorophyll, soluble protein and Rubisco contents and photosynthesis rate are not significantly altered by ambient levels of UV-B radiation (17 microW m-2, 290-320 nm, 4 h/day for one week). Comparative studies show that under high nitrogen, UV-B radiation slightly enhances leaf expansion and dry-matter accumulation in cultivar Pinto, but inhibits these parameters in Vilmorin. These results suggest that the UV-B effect on growth is mediated through leaf expansion, which is particularly sensitive to UV-B, and that Pinto is more tolerant than Vilmorin. The effect of UV-B radiation on UV-B-absorbing compounds and on NADP-malic enzyme (NADP-ME) activity is also examined. Both UV-B radiation and low-nitrogen nutrition enhance the content of UV-B-absorbing compounds, and among the three cultivars used, Pinto exhibits the highest increases and Arroz the lowest. The same trend is observed for the specific activity and content of NADP-ME. On a leaf-area basis, the amount of UV-B-absorbing compounds is highly correlated with the enzyme activity (r2 = 0.83), suggesting that NADP-ME plays a key role in biosynthesis of these compounds. Furthermore, the higher sensitivity of Vilmorin than Pinto to UV-B radiation appears to be related to the activity of NADP-ME and the capacity of the plants to accumulate UV-B-absorbing compounds.

Degradation mechanisms of Microcystin-LR during UV-B photolysis and UV/H2O2 processes: Byproducts and pathways.

Science.gov (United States)

Moon, Bo-Ram; Kim, Tae-Kyoung; Kim, Moon-Kyung; Choi, Jaewon; Zoh, Kyung-Duk

2017-10-01

The removal and degradation pathways of microcystin-LR (MC-LR, [M+H] +  = 995.6) in UV-B photolysis and UV-B/H 2 O 2 processes were examined using liquid chromatography-tandem mass spectrometry. The UV/H 2 O 2 process was more efficient than UV-B photolysis for MC-LR removal. Eight by-products were newly identified in the UV-B photolysis ([M+H] +  = 414.3, 417.3, 709.6, 428.9, 608.6, 847.5, 807.4, and 823.6), and eleven by-products were identified in the UV-B/H 2 O 2 process ([M+H] +  = 707.4, 414.7, 429.3, 445.3, 608.6, 1052.0, 313.4, 823.6, 357.3, 245.2, and 805.7). Most of the MC-LR by-products had lower [M+H] + values than the MC-LR itself during both processes, except for the [M+H] + value of 1052.0 during UV-B photolysis. Based on identified by-products and peak area patterns, we proposed potential degradation pathways during the two processes. Bond cleavage and intramolecular electron rearrangement by electron pair in the nitrogen atom were the major reactions during UV-B photolysis and UV-B/H 2 O 2 processes, and hydroxylation by OH radical and the adduct formation reaction between the produced by-products were identified as additional pathways during the UV-B/H 2 O 2 process. Meanwhile, the degradation by-products identified from MC-LR during UV-B/H 2 O 2 process can be further degraded by increasing H 2 O 2 dose. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-inflammatory and antioxidant effects of Aloe saponaria Haw in a model of UVB-induced paw sunburn in rats.

Science.gov (United States)

Silva, Mariane Arnoldi; Trevisan, Gabriela; Hoffmeister, Carin; Rossato, Mateus Fortes; Boligon, Aline Augusti; Walker, Cristiani Isabel Banderò; Klafke, Jonatas Zeni; Oliveira, Sara Marchesan; Silva, Cássia Regina; Athayde, Margareth Linde; Ferreira, Juliano

2014-04-05

Ultraviolet B (UVB) irradiation mainly affects biological tissues by inducing an increase in reactive oxygen species (ROS) production which leads to deleterious outcomes for the skin, including pain and inflammation. As a protective strategy, many studies have focused on the use of natural products. The aim of this study was to investigate the effects of Aloe saponaria on nociceptive, inflammatory, and oxidative parameters in a model of UVB-induced sunburn in adult male Wistar rats. Sunburned animals were topically treated with vehicle (base cream), 1% silver sulfadiazine (positive control) or A. saponaria (10%) once a day for 6days. UVB-induced nociception (allodynia and hyperalgesia), inflammation (edema and leukocyte infiltration) and oxidative stress (increases in H2O2, protein carbonyl levels and lipid peroxidation and a decrease in non protein thiol content) were reduced by both A. saponaria and sulfadiazine topical treatment. Furthermore, A. saponaria or its constituents aloin and rutin reduced the oxidative stress induced by H2O2 in skin homogenates in vitro. Our results demonstrate that topical A. saponaria treatment displayed anti-nociceptive and anti-inflammatory effects in a UVB-induced sunburn model, and these effects seem to be related to its antioxidant components. Copyright © 2014 Elsevier B.V. All rights reserved.

Responses of He-Ne laser on agronomic traits and the crosstalk between UVR8 signaling and phytochrome B signaling pathway in Arabidopsis thaliana subjected to supplementary ultraviolet-B (UV-B) stress.

Science.gov (United States)

Gao, Limei; Li, Yongfeng; Shen, Zhihua; Han, Rong

2018-05-01

UV-B acclimation effects and UV-B damage repair induced by a 632.8-nm He-Ne laser were investigated in Arabidopsis thaliana plants in response to supplementary UV-B stress. There was an increasing trend in growth parameters in the combination-treated plants with He-Ne laser and UV-B light compared to those stressed with enhanced UV-B light alone during different developmental stages of plants. The photosynthetic efficiency (Pn) and survival rates of seedlings were significantly higher in the combination treatments than UV-B stress alone. The expression of UVR8, phytochrome B (PhyB), and their mediated signal responsive genes such as COP1, HY5, and CHS were also significantly upregulated in plants with the laser irradiation compared with other groups without the laser. Levels of flavonol accumulation in leaves and capsule yield of He-Ne laser-treated plants were increased. The phyB-9 mutants were more sensitive to enhanced UV-B stress and had no obvious improvements in plant phenotypic development and physiological damage caused by enhanced UV-B stress after He-Ne laser irradiation. Our results suggested that UVR8 and its mediated signaling pathway via interaction with COP1 can be induced by He-Ne laser, and these processes were dependent on cytoplasmic PhyB levels in plant cells, which might be one of the most important mechanisms of He-Ne laser on UV-B protection and UV-B damage repair. These current data have also elucidated that the biostimulatory effects of He-Ne laser on Arabidopsis thaliana plants would happen not only during the early growth stage but also during the entire late developmental stage.

RNA-Seq transcriptomic analysis of the Morus alba L. leaves exposed to high-level UVB with or without dark treatment.

Science.gov (United States)

Guan, Qijie; Yu, Jiaojiao; Zhu, Wei; Yang, Bingxian; Li, Yaohan; Zhang, Lin; Tian, Jingkui

2018-03-01

Ultraviolet-B (UVB) irradiation induces oxidative stress in plant cells due to the generation of excessive reactive oxygen species. Morus alba L. (M. abla) is an important medicinal plant used for the treatment of human diseases. Also, its leaves are widely used as food for silkworms. In our previous research, we found that a high level of UVB irradiation with dark incubation led to the accumulation of secondary metabolites in M. abla leaf. The aim of the present study was to describe and compare M. alba leaf transcriptomics with different treatments (control, UVB, UVB+dark). Leaf transcripts from M. alba were sequenced using an Illumina Hiseq 2000 system, which produced 14.27Gb of data including 153,204,462 paired-end reads among the three libraries. We de novo assembled 133,002 transcripts with an average length of 1270bp and filtered 69,728 non-redundant unigenes. A similarity search was performed against the non-redundant National Center of Biotechnology Information (NCBI) protein database, which returned 41.08% hits. Among the 20,040 unigenes annotated in UniProtKB/SwissProt database, 16,683 unigenes were assigned 102,232 gene ontology terms and 6667 unigenes were identified in 287 known metabolic pathways. Results of differential gene expression analysis together with real-time quantitative PCR tests indicated that UVB irradiation with dark incubation enhanced the flavonoid biosynthesis in M. alba leaf. Our findings provided a valuable proof for a better understanding of the metabolic mechanism under abiotic stresses in M. alba leaf. Copyright © 2017 Elsevier B.V. All rights reserved.

Alterations in the antibacterial potential of Synechococcus spp. PCC7942 under the influence of UV-B radiations on skin pathogens

Directory of Open Access Journals (Sweden)

Nida Fatima

2017-11-01

Full Text Available Marine organisms are seen as a source of novel drugs and the discovery of new pharmaceutical is increasingly in demand. Cyanobacteria are regarded as a potential target for this as antibacterial, antiviral, antifungal, algicide and cytotoxic activities have been reported in these organisms. They have been identified as a new and rich source of bioactive compounds belonging to diversified groups. Radiation in the UV-B range interferes with various metabolic reactions by generating free radicals and active oxygen species. These deleterious compounds are inactivated by antioxidants. Among them are the carotenoids and phycocyanin which protect against photodynamic action in different ways. Stress plays an important role in the production of bioactive metabolites from organisms. Synechococcus spp. PCC7942 was studied for antibacterial activity against various pathogenic bacteria resistant to a number of available antibiotics after being exposed to UV-B radiation. The antibacterial activity of Synechococcus spp. PCC7942 was studied on five potent skin pathogens. The highest antibacterial activity was seen the methanol extracts of 24 h UV-B exposed cultures of Synechococcus spp. PCC7942. It can be concluded that there was moderate antibacterial activity. Results showed stress, solvent and dose-dependent activity. This antibacterial activity might be due to the enhanced synthesis of carotenoids and phycocyanin under UV-B stress. The purpose of the present study was to relate the inhibitory effects of the cyanobacterial compounds specifically on skin pathogens with exposure to UV-B radiation as UV protecting compounds are already reported in these organisms.

Temporal variation of erythemally effective UVB/UVA ratio at Chilton, UK

International Nuclear Information System (INIS)

Hooke, R. J.; Pearson, A. J.; O'Hagan, J. B.

2012-01-01

An analysis of the temporal variation in the erythemally weighted UVB/UVA irradiance ratio using spectral data collected from a monitoring site in Chilton, UK (51 deg. N) for the 5-y period from 2004 to 2008 is presented. The variation in the diurnal ratio was found to be bell-shaped, with minima on average 1 h after sunrise and before sunset. The minima were found to be indicative of the point at which UVB becomes undetectable by the spectro-radiometer and therefore the outer boundary of useful data. A potential flaw entailed in the erythemal weighting of low-level spectral UV data is described. The peak daily ratio value was found to have a bell-shaped distribution over the course of a year with a maximum in July rather than at the summer solstice-a result explained by the ozone cycle. The peak daily ratio was found to vary by a factor of 4 over the course of the year; this range of variation was also found to occur over a single day in the summer. (authors)