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Photoprotection

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https://www.readbyqxmd.com/read/28743100/studies-on-secondary-metabolite-profiling-anti-inflammatory-potential-in-vitro-photoprotective-and-skin-aging-related-enzyme-inhibitory-activities-of-malaxis-acuminata-a-threatened-orchid-of-nutraceutical-importance
#1
Biswajit Bose, Hiranjit Choudhury, Pramod Tandon, Suman Kumaria
Malaxis acuminata D. Don., a small, terrestrial orchid, is endemic to tropical Himalayas at an altitude of 1200-2000m asl. The dried pseudobulbs are important ingredients of century old ayurvedic drug 'Ashtavarga' and a polyherbal immune-booster nutraceutical 'Chyavanprash', known to restore vigour, vitality and youthfulness. Considering tremendous medicinal importance of this threatened orchid species, a detailed study was undertaken for the first time to address its antioxidant potential, secondary metabolite contents and biological activities against skin-aging related enzymes (anti-collagenase, anti-elastase, anti-tyrosinase and xanthine oxidase) and anti-inflammatory activity (5-lipoxygenase and hyaluronidase) in different plant parts of wild and in vitro-derived plants of M...
July 12, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28742490/observing-and-understanding-the-ultrafast-photochemistry-in-small-molecules-applications-to-sunscreens
#2
Lewis A Baker, Vasilios G Stavros
In this review, we discuss the importance of biological and artificial photoprotection against overexposure to harmful ultraviolet radiation. Transient electronic and transient vibrational absorption spectroscopies are highlighted as important tools in understanding the energy transfer in small molecules, with a focus on the application to commercial sunscreens with representative examples given. Oxybenzone, a common ingredient in commercial sunscreens and sinapoyl malate, a biological sunscreen in plant leaves are presented as case studies...
September 1, 2016: Science Progress
https://www.readbyqxmd.com/read/28734933/photosystem-ii-cyclic-electron-flow-powers-exceptional-photoprotection-and-record-growth-in-the-microalga-chlorella-ohadii
#3
Gennady Ananyev, Colin Gates, Aaron Kaplan, G Charles Dismukes
The desert microalga Chlorella ohadii was reported to grow at extreme light intensities with minimal photoinhibition, tolerate frequent de/re-hydrations, yet minimally employs antenna-based non-photochemical quenching for photoprotection. Here we investigate the molecular mechanisms by measuring Photosystem II charge separation yield (chlorophyll variable fluorescence, Fv/Fm) and flash-induced O2 yield to measure the contributions from both linear (PSII-LEF) and cyclic (PSII-CEF) electron flow within PSII. Cells grow increasingly faster at higher light intensities (μE/m(2)/s) from low (20) to high (200) to extreme (2000) by escalating photoprotection via shifting from PSII-LEF to PSII-CEF...
July 19, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28725228/unraveling-the-photoprotective-response-of-lichenized-and-free-living-green-algae-trebouxiophyceae-chlorophyta-to-photochilling-stress
#4
Fátima Míguez, Ulf Schiefelbein, Ulf Karsten, José I García-Plazaola, Lydia Gustavs
Lichens and free-living terrestrial algae are widespread across many habitats and develop successfully in ecosystems where a cold winter limits survival. With the goal of comparing photoprotective responses in free-living and lichenized algae, the physiological responses to chilling and photochilling conditions were studied in three lichens and their isolated algal photobionts together as well as in a fourth free-living algal species. We specifically addressed the following questions: (i) Are there general patterns of acclimation in green algae under chilling and photochilling stresses? (ii) Do free-living algae exhibit a similar pattern of responses as their lichenized counterparts? (iii) Are these responses influenced by the selection pressure of environmental conditions or by the phylogenetic position of each species? To answer these questions, photosynthetic fluorescence measurements as well as pigment and low molecular weight carbohydrate pool analyses were performed under controlled laboratory conditions...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28721563/terrestrial-adaptation-of-green-algae-klebsormidium-and-zygnema-charophyta-involves-diversity-in-photosynthetic-traits-but-not-in-co2-acquisition
#5
Mattia Pierangelini, David Ryšánek, Ingeborg Lang, Wolfram Adlassnig, Andreas Holzinger
The basal streptophyte Klebsormidium and the advanced Zygnema show adaptation to terrestrialization. Differences are found in photoprotection and resistance to short-term light changes, but not in CO 2 acquisition. Streptophyte green algae colonized land about 450-500 million years ago giving origin to terrestrial plants. We aim to understand how their physiological adaptations are linked to the ecological conditions (light, water and CO2) characterizing modern terrestrial habitats. A new Klebsormidium isolate from a strongly acidic environment of a former copper mine (Schwarzwand, Austria) is investigated, in comparison to Klebsormidium cf...
July 18, 2017: Planta
https://www.readbyqxmd.com/read/28716924/insights-into-the-red-algae-and-eukaryotic-evolution-from-the-genome-of-porphyra-umbilicalis-bangiophyceae-rhodophyta
#6
Susan H Brawley, Nicolas A Blouin, Elizabeth Ficko-Blean, Glen L Wheeler, Martin Lohr, Holly V Goodson, Jerry W Jenkins, Crysten E Blaby-Haas, Katherine E Helliwell, Cheong Xin Chan, Tara N Marriage, Debashish Bhattacharya, Anita S Klein, Yacine Badis, Juliet Brodie, Yuanyu Cao, Jonas Collén, Simon M Dittami, Claire M M Gachon, Beverley R Green, Steven J Karpowicz, Jay W Kim, Ulrich Johan Kudahl, Senjie Lin, Gurvan Michel, Maria Mittag, Bradley J S C Olson, Jasmyn L Pangilinan, Yi Peng, Huan Qiu, Shengqiang Shu, John T Singer, Alison G Smith, Brittany N Sprecher, Volker Wagner, Wenfei Wang, Zhi-Yong Wang, Juying Yan, Charles Yarish, Simone Zäuner-Riek, Yunyun Zhuang, Yong Zou, Erika A Lindquist, Jane Grimwood, Kerrie W Barry, Daniel S Rokhsar, Jeremy Schmutz, John W Stiller, Arthur R Grossman, Simon E Prochnik
Porphyra umbilicalis (laver) belongs to an ancient group of red algae (Bangiophyceae), is harvested for human food, and thrives in the harsh conditions of the upper intertidal zone. Here we present the 87.7-Mbp haploid Porphyra genome (65.8% G + C content, 13,125 gene loci) and elucidate traits that inform our understanding of the biology of red algae as one of the few multicellular eukaryotic lineages. Novel features of the Porphyra genome shared by other red algae relate to the cytoskeleton, calcium signaling, the cell cycle, and stress-tolerance mechanisms including photoprotection...
July 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28716091/suppression-of-the-phytoene-synthase-gene-egcrtb-alters-carotenoid-content-and-intracellular-structure-of-euglena-gracilis
#7
Shota Kato, Mika Soshino, Shinichi Takaichi, Takahiro Ishikawa, Noriko Nagata, Masashi Asahina, Tomoko Shinomura
BACKGROUND: Photosynthetic organisms utilize carotenoids for photoprotection as well as light harvesting. Our previous study revealed that high-intensity light increases the expression of the gene for phytoene synthase (EgcrtB) in Euglena gracilis (a unicellular phytoflagellate), the encoded enzyme catalyzes the first committed step of the carotenoid biosynthesis pathway. To examine carotenoid synthesis of E. gracilis in response to light stress, we analyzed carotenoid species and content in cells grown under various light intensities...
July 17, 2017: BMC Plant Biology
https://www.readbyqxmd.com/read/28704942/specialized-metabolites-of-the-lichen-vulpicida-pinastri-act-as-photoprotective-agents
#8
Béatrice Legouin, Françoise Lohézic-Le Dévéhat, Solenn Ferron, Isabelle Rouaud, Pierre Le Pogam, Laurence Cornevin, Michel Bertrand, Joël Boustie
The extreme resiliency of lichens to UV radiations makes them an interesting model to find new photoprotective agents acting as UV-blockers and antioxidant. In this research, using a new in vitro method designed to overcome the shortage of material associated to many studies dealing with natural products, we show that the three major compounds isolated from the lichen Vulpicida pinastri, vulpinic acid, pinastric acid and usnic acid, were UV blocker agents. Antioxidant assays evidenced superoxide anion scavenging activity...
July 12, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28702744/plant-extracts-and-natural-compounds-used-against-uvb-induced-photoaging
#9
REVIEW
Maria Cavinato, Birgit Waltenberger, Giorgia Baraldo, Carla V C Grade, Hermann Stuppner, Pidder Jansen-Dürr
Skin is continuously exposed to a variety of environmental stresses, including ultraviolet (UV) radiation. UVB is an inherent component of sunlight that crosses the epidermis and reaches the upper dermis, leading to increased oxidative stress, activation of inflammatory response and accumulation of DNA damage among other effects. The increase in UVB radiation on earth due to the destruction of stratospheric ozone poses a major environmental threat to the skin, increasing the risk of damage with long-term consequences, such as photoaging and photocarcinogenesis...
July 12, 2017: Biogerontology
https://www.readbyqxmd.com/read/28692285/raman-optical-activity-reveals-carotenoid-photoactivation-events-in-the-orange-carotenoid-protein-in-solution
#10
Tomotsumi Fujisawa, Ryan L Leverenz, Momoka Nagamine, Cheryl A Kerfeld, Masashi Unno
The orange carotenoid protein (OCP) plays an important role in photoprotection in cyanobacteria, which is achieved by the photoconversion from the orange dark state (OCPO) to the red active state (OCPR). Using Raman optical activity (ROA), we studied the conformations of the carotenoid chromophore in the active sites of OCPO and OCPR. This ROA measurement directly observed the chromophore conformation of native OCP in solution, and the measurement of OCPR first demonstrated the ROA spectroscopy for the transient species...
July 10, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28692021/additional-families-of-orange-carotenoid-proteins-in-the-photoprotective-system-of-cyanobacteria
#11
Han Bao, Matthew R Melnicki, Emily G Pawlowski, Markus Sutter, Marco Agostoni, Sigal Lechno-Yossef, Fei Cai, Beronda L Montgomery, Cheryl A Kerfeld
The orange carotenoid protein (OCP) is a structurally and functionally modular photoactive protein involved in cyanobacterial photoprotection. Using phylogenomic analysis, we have revealed two new paralogous OCP families, each distributed among taxonomically diverse cyanobacterial genomes. Based on bioinformatic properties and phylogenetic relationships, we named the new families OCP2 and OCPx to distinguish them from the canonical OCP that has been well characterized in Synechocystis, denoted hereafter as OCP1...
July 10, 2017: Nature Plants
https://www.readbyqxmd.com/read/28690624/transcriptome-wide-identification-of-novel-uv-b-and-light-modulated-flavonol-pathway-genes-controlled-by-vvimybf1
#12
Stefan Czemmel, Janine Höll, Rodrigo Loyola, Patricio Arce-Johnson, José Antonio Alcalde, José Tomás Matus, Jochen Bogs
Flavonols constitute a group of flavonoids with important photoprotective roles in plants. In addition, flavonol content and composition greatly influences fruit quality. We previously demonstrated that the grapevine R2R3-MYB transcription factor (TF) VviMYBF1 promotes flavonol accumulation by inducing the expression of flavonol synthase (VviFLS1/VviFLS4), a key step of the initial flavonol pathway. Despite this, gene networks underlying flavonol modification in grapevine including both structural and regulatory genes remain poorly understood...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28681588/response-of-linear-and-cyclic-electron-flux-to-moderate-high-temperature-and-high-light-stress-in-tomato
#13
Tao Lu, Jie-Wei Shi, Zhou-Ping Sun, Ming-Fang Qi, Yu-Feng Liu, Tian-Lai Li
OBJECTIVE: To evaluate the possible photoprotection mechanisms of cyclic and linear electron flux (CEF and LEF) under specific high temperature and high light (HH) stress. METHODS: Six-leaf-stage tomato seedlings ("Liaoyuanduoli", n=160) were divided into four parts: Part 1, served as control under 25 °C, 500 µmol/(m(2)·s); Part 2, spayed with distilled water (H2O) under 35 °C, 1000 µmol/(m(2)·s) (HH); Part 3, spayed with 100 µmol/L diuron (DCMU, CEF inhibitor) under HH; Part 4, spayed with 60 µmol/L methyl viologen (MV, LEF inhibitor) under HH...
July 2017: Journal of Zhejiang University. Science. B
https://www.readbyqxmd.com/read/28680948/development-and-evaluation-of-photoprotective-o-w-emulsions-containing-hydroalcoholic-extract-of-neoglaziovia-variegata-bromeliaceae
#14
Raimundo Gonçalves de Oliveira-Júnior, Grasielly Rocha Souza, Christiane Adrielly Alves Ferraz, Ana Paula de Oliveira, Camila de Souza Araújo, Sarah Raquel Gomes de Lima-Saraiva, Silvio Alan Gonçalves Bomfim Reis, Talita Mota Gonçalves, Larissa Araújo Rolim, Pedro José Rolim-Neto, Francine Celise Siqueira César, Jackson Roberto Guedes da Silva Almeida
Neoglaziovia variegata is a Bromeliaceae plant species widely found in Brazil with several pharmacological properties, including photoprotective activity. Although herbal-based active ingredients have been applied in cosmetic products, especially for skin treatment, its application in sunscreen formulations remains unexplored. The aim of this work is to evaluate the photoprotective effect of cosmetic formulations containing hydroalcoholic extract of N. variegata (Nv-HA). Initially, the phenolic and flavonoid total content of Nv-HA were determined...
2017: TheScientificWorldJournal
https://www.readbyqxmd.com/read/28674548/photoprotective-strategies-of-mediterranean-plants-in-relation-to-morphological-traits-and-natural-environmental-pressure-a-meta-analytical-approach
#15
Beatriz Fernández-Marín, Antonio Hernández, Jose I Garcia-Plazaola, Raquel Esteban, Fátima Míguez, Unai Artetxe, Maria T Gómez-Sagasti
Despite being a small geographic extension, Mediterranean Basin is characterized by an exceptional plant biodiversity. Adaptive responses of this biocoenosis are delineated by an unusual temporal dissociation along the year between optimal temperature for growth and water availability. This fact generates the combination of two environmental stress factors: a period of summer drought, variable in length and intensity, and the occurrence of mild to cold winters. Both abiotic factors, trigger the generation of (photo)oxidative stress and plants orchestrate an arsenal of structural, physiological, biochemical, and molecular mechanisms to withstand such environmental injuries...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28667107/the-two-cryptochrome-photolyase-family-proteins-fulfill-distinct-roles-in-dna-photorepair-and-regulation-of-conidiation-in-the-gray-mold-fungus-botrytis-cinerea
#16
Kim C Cohrs, Julia Schumacher
The plant pathogenic Leotiomycete Botrytis cinerea is known for the strict regulation of its asexual differentiation programs by the environmental light conditions. Sclerotia are formed in constant darkness, black/near-UV (NUV) light induces conidiation and blue light represses both differentiation programs. Sensing of black/NUV light is attributed to proteins of the cryptochrome/photolyase family (CPF). To elucidate the molecular basis of the photoinduction of conidiation, we functionally characterized the two CPF proteins encoded in the genome of B...
June 30, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28664534/does-triacylglycerol-tag-serve-a-photoprotective-function-in-plant-leaves-an-examination-of-leaf-lipids-under-shading-and-drought
#17
Renée M Marchin, Tarryn L Turnbull, Audrey I Deheinzelin, Mark A Adams
Plant survival in many ecosystems requires tolerance of large radiation loads, unreliable water supply, and suboptimal soil fertility. We hypothesized that increased production of neutral lipids (triacylglycerols, TAGs) in plant leaves is a mechanism for dissipating excess radiation energy. In a greenhouse experiment, we combined drought and shade treatments and examined responses among four species differing in life form, habitat, and drought- and shade-tolerance. We also present a lipid extraction protocol suitable for sclerophyllous leaves of native Australian trees (e...
June 29, 2017: Physiologia Plantarum
https://www.readbyqxmd.com/read/28661544/efficacy-of-a-daily-protective-moisturizer-with-high-uvb-and-uva-photoprotection-in-decreasing-ultraviolet-damage-evaluation-by-reflectance-confocal-microscopy
#18
Antonio Gomes-Neto, Paula Aguilera, Leonor Prieto, Sophie Seité, Dominique Moyal, Cristina Carrera, Josep Malvehy, Susana Puig
Patients with photodermatoses or actinic keratoses benefit from very high ultraviolet B-ultraviolet A (UVB-UVA) photoprotection. However, poor compliance is an issue that jeopardizes adequate protection, leading to disease recurrence. This study evaluated the efficacy of a daily protective moisturizer with high UVB and UVA photoprotection applied 8 h before irradiation. A monocentric, open-label, prospective, control pilot study was performed including 10 patients. Patients were irradiated with UVB and UVA before and 8 h after topical application of the product...
June 29, 2017: Acta Dermato-venereologica
https://www.readbyqxmd.com/read/28657653/intrinsic-photoprotective-mechanisms-in-chlorophylls
#19
Leszek Fiedor, Alina Dudkowiak, Michał Kotkowiak
Photosynthetic energy conversion inevitably competes with the formation of Chl triplet states and the generation of reactive oxygen species. Hence, many sophisticated photoprotective mechanisms have evolved to secure a harmless flow of energy through the photosynthetic complexes. We used time-resolved optoacoustic spectroscopy to compare the properties of the T1 states of pheophytin a and its metallocomplexes, and found that the lowest quantum yield of the T1 state is always observed in the Mg complex, which also shows the least efficient energy transfer to O2...
June 28, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28654327/a-new-facet-of-vitamin-b12-gene-regulation-by-cobalamin-based-photoreceptors
#20
REVIEW
S Padmanabhan, Marco Jost, Catherine L Drennan, Montserrat Elías-Arnanz
Living organisms sense and respond to light, a crucial environmental factor, using photoreceptors, which rely on bound chromophores such as retinal, flavins, or linear tetrapyrroles for light sensing. The discovery of photoreceptors that sense light using 5'-deoxyadenosylcobalamin, a form of vitamin B12 that is best known as an enzyme cofactor, has expanded the number of known photoreceptor families and unveiled a new biological role of this vitamin. The prototype of these B12-dependent photoreceptors, the transcriptional repressor CarH, is widespread in bacteria and mediates light-dependent gene regulation in a photoprotective cellular response...
June 20, 2017: Annual Review of Biochemistry
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