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Photoprotection systemic

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https://read.qxmd.com/read/30768968/chlortetracycline-and-melanin-biopolymer-the-risk-of-accumulation-and-implications-for-phototoxicity-an-in-vitro-study-on-normal-human-melanocytes
#1
Jakub Rok, Zuzanna Rzepka, Michalina Respondek, Artur Beberok, Dorota Wrześniok
Tetracyclines belong to antimicrobial classes with the highest consumption in veterinary medicine and agriculture, which leads to the contamination of the environment and food products, as well as to antibiotic resistance and adverse drug reactions. Chloro-derivatives of tetracyclines are thought to be relatively more phototoxic than others and belong to the most frequently cited drugs as photosensitizers. Melanins are heterogenous biopolymers determining skin, hair and eye colour. They are biosynthesized in a multistep process in melanocytes...
February 12, 2019: Chemico-biological Interactions
https://read.qxmd.com/read/30718349/fluctuating-light-interacts-with-time-of-day-and-leaf-development-stage-to-reprogram-gene-expression
#2
Trang Schneider, Anthony Bolger, Jürgen Zeier, Sabine Preiskowski, Vladimir Benes, Sandra Trenkamp, Bjoern Usadel, Eva M Farre, Shizue Matsubara
Natural-light environments are highly variable. Flexible adjustment between light energy utilization and photoprotection is therefore of vital importance for plant performance and fitness in the field. Short-term reactions to changing light intensity are triggered inside chloroplasts and leaves within seconds to minutes, whereas long-term adjustments proceed over hours and days, integrating multiple signals. While the mechanisms of long-term acclimation to light intensity have been studied by changing constant growth light intensity during the day, responses to fluctuating growth light intensity have rarely been inspected in detail...
February 4, 2019: Plant Physiology
https://read.qxmd.com/read/30682442/recent-advances-in-topical-delivery-of-flavonoids-a-review
#3
REVIEW
Ruchika L Nagula, Sarika Wairkar
Flavonoids are one of the vital classes of bioactive chemicals, abundantly found in plants. These are natural polyphenolic compounds derived from plant metabolites. Their lipophilic nature and poor solubility lead to variable and limited oral bioavailability. The substantial pharmacological properties of flavonoids include antioxidant, anti-inflammatory, antiproliferative, photoprotective, depigmentation, anti-aging which are very promising in the treatment of several skin disorders. Thus, various topical delivery systems of flavonoids have been extensively studied...
January 22, 2019: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://read.qxmd.com/read/30669361/uv-photoprotection-cytotoxicity-and-immunology-capacity-of-red-algae-extracts
#4
Félix Álvarez-Gómez, Nathalie Korbee, Virginia Casas-Arrojo, Roberto T Abdala-Díaz, Félix L Figueroa
This study was designed to evaluate the potential use of algal extracts in cosmeceuticals, including factors related to biosecurity. The aqueous crude extracts of Hydropuntia cornea and Gracilariopsis longissima showed a good photoprotective capacity (Sun Protection Factor, SPF) due to, among other reasons, the presence of five types of mycosporine-like amino acids (MAAs) detected by high pressure liquid chromatography-photodiode array detector (HPLC-PDA) and electrospray ionization mass spectrometry (ESI-MS) (Palythine, Asterina-330, Shinorine, Porphyra-334, and Palythinol)...
January 18, 2019: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://read.qxmd.com/read/30639535/ab-initio-model-for-the-chlorophyll-lutein-exciton-coupling-in-the-lhcii-complex
#5
Daniil Khokhlov, Aleksandr Belov
2Ag - state of lutein plays a crucial role in photoprotection of higher plants. Due to its multiconfigurational nature, accurate description of this electronic state and respective transition properties is a formidable task. In this paper, applicability of various CASSCF and RASSCF formulations for description of the 2Ag - state is discussed. It is shown that inclusion of the entire π-system of lutein into the active space is required for accurate calculation of transition properties. Exciton coupling in the chlorophyll-lutein dimer involved in non-photochemical quenching in the LHCII complex was calculated to provide a connection between pigment interactions and non-photochemical quenching regulation...
January 3, 2019: Biophysical Chemistry
https://read.qxmd.com/read/30578537/multilevel-regulation-of-non-photochemical-quenching-and-state-transitions-by-chloroplast-nadph-dependent-thioredoxin-reductase
#6
Lauri Nikkanen, Manuel Guinea Diaz, Jouni Toivola, Arjun Tiwari, Eevi Rintamäki
In natural growth habitats, plants face constant, unpredictable changes in light conditions. To avoid damage to the photosynthetic apparatus on thylakoid membranes in chloroplasts, and to avoid wasteful reactions, it is crucial to maintain a redox balance both within the components of photosynthetic electron transfer chain and between the light reactions and stromal carbon metabolism under fluctuating light conditions. This requires coordinated function of the photoprotective and regulatory mechanisms, such as non-photochemical quenching (NPQ) and reversible redistribution of excitation energy between photosystem II (PSII) and photosystem I (PSI)...
December 22, 2018: Physiologia Plantarum
https://read.qxmd.com/read/30561763/ultrastructural-patterns-of-photoacclimation-and-photodamage-to-photosynthetic-algae-cell-under-environmental-stress
#7
Alexei Solovchenko, Olga Baulina, Oksana Ptushenko, Olga Gorelova
In oxygenic phototrophs including unicellular algae, acclimation to and damage by diverse environmental stresses induce profound changes in the ultrastructural organization of the cell. These alterations reflect acclimation of the photosynthetic apparatus to unfavorable conditions (mainly reduction of the chloroplast and its membranal system) and rewiring of the photofixed carbon fluxes in the cell. These changes, eventually pursuing mitigation of the photooxidative damage risk, are manifested by the formation of diverse carbon-rich inclusions...
December 18, 2018: Physiologia Plantarum
https://read.qxmd.com/read/30456488/changes-in-the-photosynthesis-properties-and-photoprotection-capacity-in-rice-oryza-sativa-grown-under-red-blue-or-white-light
#8
Saber Hamdani, Naveed Khan, Shahnaz Perveen, Mingnan Qu, Jianjun Jiang, Govindjee, Xin-Guang Zhu
Non-photochemical quenching (NPQ) of the excited state of chlorophyll a is a major photoprotective mechanism plants utilize to survive under high light. Here, we report the impact of long-term light quality treatment on photosynthetic properties, especially NPQ in rice. We used three LED-based light regimes, i.e., red (648-672 nm), blue (438-460 nm), and "warm" white light (529-624 nm), with the incident photon flux density of 300 µmol photons m-2  s-1 , the difference in the absorbed photon flux densities by leaves grown under different light quality being less than 7%...
November 19, 2018: Photosynthesis Research
https://read.qxmd.com/read/30453136/laser-writing-of-nanostructured-silicon-arrays-for-the-sers-detection-of-biomolecules-with-inhibited-oxidation
#9
P Pellacani, V Torres-Costa, F Agulló-Rueda, R Vanna, C Morasso, M Manso Silván
The present work reports the processing of laser irradiated Si arrays (LISi) and underlines their surface enhanced Raman scattering (SERS) functionality. A nanostructured Si/SiOx surface forms providing additional fluidic and photoprotective properties. Because of their optical and surface characteristics, the arrays exhibit a SERS analytical enhancing factor of 500, without any noble metals such as gold or silver. Micro-Raman maps allowed studying LISi properties, identifying maximum amplification in nanostructured areas characterized by the presence of 7 nm Si nanocrystals...
November 6, 2018: Colloids and Surfaces. B, Biointerfaces
https://read.qxmd.com/read/30409434/xeroderma-pigmentosum
#10
M Zghal, B Fazaa, S Abdelhak, M Mokni
Xeroderma pigmentosum (XP) is a form of general dermatosis characterised by photo-induced cutaneous-ocular impairment and by skin cancers. In addition to these signs, there may also be neurological involvement. This disease is related to a defect in genes within the nucleotide excision repair system for the first seven genetic groups (A-G), and to an abnormality in transcription groups for the eighth group (xeroderma pigmentosum variant - XPV). Cutaneous carcinomas are the most common types of cancer seen. They may begin in childhood...
November 2018: Annales de Dermatologie et de Vénéréologie
https://read.qxmd.com/read/30383815/photosynthesis-limitations-in-cacao-leaves-under-different-agroforestry-systems-in-the-colombian-amazon
#11
Juan Carlos Suárez Salazar, Luz Marina Melgarejo, Fernando Casanoves, Julio A Di Rienzo, Fabio M DaMatta, Cristina Armas
Cacao (Theobroma cacao L.) has traditionally been considered a crop that requires shade, and consequently it is implemented under agroforestry systems (AFs) in order to regulate the level of incident solar radiation. However, optimal shade levels for this tree crop may vary depending on the climate conditions of where it is grown. Here we analyzed the physiological performance of cacao under three different AFs in the Colombian Amazon that differed in solar radiation patterns: high (HPAR), medium (MPAR), or low (LPAR) mean daily incident radiation...
2018: PloS One
https://read.qxmd.com/read/30346955/antioxidant-metabolism-in-galls-due-to-the-extended-phenotypes-of-the-associated-organisms
#12
Bruno G Ferreira, Denis C Oliveira, Ana S F P Moreira, Ana P Faria, Lubia M Guedes, Marcel G C França, Rafael Álvarez, Rosy M S Isaias
Animal-induced galls are considered extended phenotypes of their inducers, and therefore plant morphogenesis and metabolism may vary according to the species of gall inducers. The alterations in vacuolar and apoplastic polyphenols, carotenoids, chlorophyll fluorescence rates, PSII quantum yield, and phospholipid peroxidation were studied in galls induced by Ditylenchus gallaeformans (Nematoda) on Miconia albicans and M. ibaguensis (Melastomataceae), and by an unidentified Eriophyidae (Acarina) on M. ibaguensis...
2018: PloS One
https://read.qxmd.com/read/30317633/intermolecular-hydrogen-bonding-modulates-o-h-photodissociation-in-molecular-aggregates-of-a-catechol-derivative
#13
Christopher Grieco, Forrest R Kohl, Yuyuan Zhang, Sangeetha Natarajan, Lluís Blancafort, Bern Kohler
The catechol functional group plays a major role in the chemical properties of a wide variety of molecules important in biology and technology. In eumelanin, intermolecular hydrogen bonding between these functional groups is thought to contribute to UV photoprotective and radical buffering properties, but the mechanisms are poorly understood. Here, aggregates of 4-t-butylcatechol are used as model systems to study how intermolecular hydrogen bonding influences photochemical pathways that may occur in eumelanin...
October 13, 2018: Photochemistry and Photobiology
https://read.qxmd.com/read/30244487/subacute-cutaneous-lupus-erythematosus-and-dermatomyositis-associated-with-anti-programmed-cell-death-pd-1-therapy
#14
A L Marano, J M Clarke, M A Morse, A Shah, W Barrow, M A Selim, R P Hall, A R Cardones
Programmed cell death 1 (PD-1) blockade has rapidly emerged as an effective therapy for a wide variety of metastatic malignancies. It has been associated with multiple immune related adverse effects, including cutaneous eruptions. We describe two patients who developed clinical and histologic findings consistent with subacute cutaneous lupus erythematosus (SCLE) after receiving PD-1 inhibitor therapy for metastatic lung cancer. We successfully treated our first one patient with systemic and topical steroids, photoprotection, and hydroxychloroquine...
September 23, 2018: British Journal of Dermatology
https://read.qxmd.com/read/30239999/tuning-the-triplet-triplet-energy-transfer-between-phthalocyanine-and-carotenoid-by-methyl-groups-on-the-conjugated-chain
#15
Tomáš Polívka
Mimicking light-harvesting and photoprotective processes of natural photosynthesis by artificial supramolecular systems is of considerable interest for artificial photosynthesis. The authors of the highlighted paper report on synthesis and spectroscopic characterization of a novel Pd-phthalocyanine-carotenoid dyads that allow to directly follow the triplet-triplet energy transfer between Pd-phthalocyanine and carotenoid. Unexpectedly, the T-T energy transfer does not follow the dependence on conjugation length of the acceptor carotenoid...
September 21, 2018: Photochemistry and Photobiology
https://read.qxmd.com/read/30196211/mercury-mobility-and-effects-in-the-salt-marsh-plant-halimione-portulacoides-uptake-transport-and-toxicity-and-tolerance-mechanisms
#16
Maria Teresa Cabrita, Bernardo Duarte, Rute Cesário, Ricardo Mendes, Holger Hintelmann, Kevin Eckey, Brian Dimock, Isabel Caçador, João Canário
The plant Halimione portulacoides, an abundant species widely distributed in temperate salt-marshes, has been previously assessed as bioindicator and biomonitor of mercury contamination in these ecosystems. The present study aims to assess uptake and distribution of total mercury (THg) and methylmercury (MMHg) within H. portulacoides, potential mercury release by volatilization through leaves, and toxicity and tolerance mechanisms by investigating plant photochemical responses. Stem cuttings of H. portulacoides were collected from a salt-marsh within the Tagus estuary natural protected area, and grown under hydroponic conditions...
February 10, 2019: Science of the Total Environment
https://read.qxmd.com/read/30109759/rapamycin-for-refractory-discoid-lupus-erythematosus
#17
Mitchell Herold, Nicholas A Richmond, Michael A Montuno, Stanton K Wesson, Kiran Motaparthi
Generalized discoid lupus erythematosus can pose a therapeutic challenge for dermatologists. Current treatment emphasizes photoprotection, topical and systemic steroids, and steroid-sparing immunosuppressive agents if necessary. Rapamycin, also known as sirolimus, selectively inhibits mammalian target of rapamycin, a regulatory kinase responsible for multiple signal transduction pathways. Mammalian target of rapamycin inhibition reduces cell division, lymphocyte proliferation, cytokine release, and downstream pathways unique from other classes of immunomodulatory drugs...
September 2018: Dermatologic Therapy
https://read.qxmd.com/read/30102774/effects-and-mechanism-of-nicotinamide-against-uva-and-or-uvb-mediated-dna-damages-in-normal-melanocytes
#18
Gagan Chhabra, Debra R Garvey, Chandra K Singh, Charlotte A Mintie, Nihal Ahmad
Melanoma incidences are increasing rapidly, and ultraviolet (UV) radiation from the sun is believed to be its major contributing factor. UV exposure causes DNA damage in skin which may initiate cutaneous skin cancers including melanoma. Melanoma arises from melanocytes, the melanin-producing skin cells, following genetic dysregulations resulting into hyperproliferative phenotype and neoplastic transformation. Both UVA and UVB exposure to the skin are believed to trigger melanocytic hyperplasia and melanomagenesis...
August 13, 2018: Photochemistry and Photobiology
https://read.qxmd.com/read/30086234/polarizable-embedding-combined-with-the-algebraic-diagrammatic-construction-tackling-excited-states-in-biomolecular-systems
#19
Maximilian Scheurer, Michael F Herbst, Peter Reinholdt, Jógvan Magnus Haugaard Olsen, Andreas Dreuw, Jacob Kongsted
We present a variant of the algebraic diagrammatic construction (ADC) scheme by combining ADC with the polarizable embedding (PE) model. The presented PE-ADC method is implemented through second and third order and is designed with the aim of performing accurate calculations of excited states in large molecular systems. Accuracy and large-scale applicability are demonstrated with three case studies, and we further analyze the importance of both state-specific and linear-response-type corrections to the excitation energies in the presence of the polarizable environment...
September 11, 2018: Journal of Chemical Theory and Computation
https://read.qxmd.com/read/30056500/effects-of-cadmium-stress-on-the-antioxidant-system-and-chlorophyll-fluorescence-characteristics-of-two-taxodium-clones
#20
Ying-Li Ma, Hui-Fang Wang, Ping Wang, Chao-Guang Yu, Si-Qian Luo, Yu-Feng Zhang, Yin-Feng Xie
The T.118 and T.406 seedlings showed strong adaptability under Cd concentrations ≤ 50 µM. The mechanisms of photoprotection in T.118 and T.406 differed in high-Cd concentrations. To explore the physiological response characteristics of Taxodium hybrids to cadmium (Cd) stress and provide basis for screening of Cd-tolerant species, the hydroponic cultivation of T.118 and T.406 seedlings was conducted to demonstrate the effects of Cd stress on seedling growth, antioxidant system, and chlorophyll fluorescence parameters...
November 2018: Plant Cell Reports
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