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Systemic photoprotection

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https://www.readbyqxmd.com/read/29625778/-the-epidermal-barrier
#1
R Abdayem, M Haftek
The skin acts as an interface between the body and its surrounding environment. The epidermis, the surface layer of the skin, is chiefly responsible for this interactive protective function. The epidermal barrier may be subdivided into three defensive systems: the photoprotective barrier, the immune barrier, and the physical and chemical barrier of the stratum corneum or horny layer. To protect against harmful ultraviolet radiation, the epidermis has absorption factors such as melanin, produced by melanocytes, and urocanic acid, which is a degradation product of filaggrin...
April 3, 2018: Annales de Dermatologie et de Vénéréologie
https://www.readbyqxmd.com/read/29565294/in-vitro-assessment-of-total-phenolic-and-flavonoid-contents-antioxidant-and-photoprotective-activities-of-crude-methanolic-extract-of-aerial-parts-of-capnophyllum-peregrinum-l-lange-apiaceae-growing-in-algeria
#2
Mostefa Lefahal, Nabila Zaabat, Radia Ayad, El Hani Makhloufi, Lakhdar Djarri, Merzoug Benahmed, Hocine Laouer, Gema Nieto, Salah Akkal
Background: Capnophyllum peregrinum (L.) Lange (Apiaceae) is the unique taxon of capnophyllum genus in Algerian flora. It has never been investigated in regards to its total phenolic and flavonoid contents and antioxidant and photoprotective activities. Methods: C. peregrinum aerial parts extracted with absolute methanol. The total flavonoid and phenolic contents of the extract were evaluated to determine their correlation with the antioxidant and photoprotective activities of the extract. Results: The methanolic extract demonstrated a significant amount of phenolics and flavonoids (74...
March 22, 2018: Medicines (Basel, Switzerland)
https://www.readbyqxmd.com/read/29564230/vitamin-b12-determination-in-milk-whey-and-different-by-products-of-ricotta-cheese-production-by-ultra-performance-liquid-chromatography-coupled-with-tandem-mass-spectrometry
#3
Adele Repossi, Elisa Zironi, Teresa Gazzotti, Andrea Serraino, Giampiero Pagliuca
Vitamin B12 (cobalamin) is a metal complex composed of a central cobalt ion bonded to six ligands. It is essential for major biological functions such as protein, fat and carbohydrate metabolism, the maintenance of the central nervous system, and the formation of red blood cells. Since mammals cannot synthesize cobalamin, dietary intake represents the only natural source for humans. Dairy products can provide significant levels of cobalamin; moreover, the European Food Safety Authority (EFSA) panel has set the recommended intake at 4 μg/day for adults...
October 20, 2017: Italian Journal of Food Safety
https://www.readbyqxmd.com/read/29547525/sunscreen-based-photocages-for-topical-drugs-a-photophysical-and-photochemical-study-of-a-diclofenac-avobenzone-dyad
#4
Isabel Aparici-Espert, Miguel A Miranda, Virginie Lhiaubet-Vallet
Photosensitization by drugs is a problem of increasing importance in modern life. This phenomenon occurs when a chemical substance in the skin is exposed to sunlight. Photosensitizing drugs are reported to cause severe skin dermatitis, and indeed, it is generally advised to avoid sunbathing and to apply sunscreen. In this context, the nonsteroidal anti-inflammatory drug (NSAID) diclofenac is a photosensitive drug, especially when administered in topical form. In this work, efforts have been made to design and study an innovative pro-drug/pro-filter system containing diclofenac and the UVA filter avobenzone in order to develop a safer use of this topical drug...
March 16, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29524381/functional-interaction-of-low-homology-frps-from-different-cyanobacteria-with-synechocystis-ocp
#5
Yury B Slonimskiy, Eugene G Maksimov, Evgeny P Lukashev, Marcus Moldenhauer, Cy M Jeffries, Dmitri I Svergun, Thomas Friedrich, Nikolai N Sluchanko
Photosynthesis requires a balance between efficient light harvesting and protection against photodamage. The cyanobacterial photoprotection system uniquely relies on the functioning of the photoactive orange carotenoid protein (OCP) that under intense illumination provides fluorescence quenching of the light-harvesting antenna complexes, phycobilisomes. The recently identified fluorescence recovery protein (FRP) binds to the photoactivated OCP and accelerates its relaxation into the basal form, completing the regulatory circle...
March 7, 2018: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29505675/lipid-nanoparticles-sln-nlc-for-delivery-of-vitamin-e-a-comprehensive-review
#6
REVIEW
Vivian Saez, Ingrid D L de Souza, Cláudia Regina Elias Mansur
The antioxidative and photoprotective properties of vitamin E have caused it to be included as an active agent in various pharmaceutical and cosmetic products. However, its lipophilicity, chemical instability, and poor skin penetration have limited the effectiveness of these formulations. For that reason, many attempts to include it in different drug delivery systems have been made. In recent decades, lipid nanoparticles have received special attention due to their advantages of compatibility with the skin, ability to enhance penetration of drugs in the stratum corneum, protection of the encapsulated substance against degradation induced by the external medium, and control of drug release...
March 5, 2018: International Journal of Cosmetic Science
https://www.readbyqxmd.com/read/29501490/physiological-validation-of-photochemical-reflectance-index-pri-as-a-photosynthetic-parameter-using-arabidopsis-thaliana-mutants
#7
Kaori Kohzuma, Kouki Hikosaka
Non-photochemical quenching (NPQ) is the most important photoprotective system in higher plants. NPQ can be divided into several steps according to the timescale of relaxation of chlorophyll fluorescence after reaching a steady state (i.e., the fast phase, qE; middle phase, qZ or qT; and slow phase, qI). The dissipation of excess energy as heat during the xanthophyll cycle, a large component of NPQ, is detectable during the fast to middle phase (sec to min). Although thermal dissipation is primarily investigated using indirect methods such as chlorophyll a fluorescence measurements, such analyses require dark adaptation or the application of a saturating pulse during measurement, making it difficult to continuously monitor this process...
February 28, 2018: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/29482031/the-chitosan-porphyrazine-hybrid-materials-and-their-photochemical-properties
#8
Dorota Chełminiak-Dudkiewicz, Marta Ziegler-Borowska, Magdalena Stolarska, Lukasz Sobotta, Michal Falkowski, Jadwiga Mielcarek, Tomasz Goslinski, Jolanta Kowalonek, Katarzyna Węgrzynowska-Drzymalska, Halina Kaczmarek
Three magnesium sulfanyl porphyrazines differing in the size of peripheral substituents (3,5-dimethoxybenzylsulfanyl, (3,5-dimethoxybenzyloxy)benzylsulfanyl, 3,5-bis[(3,5-bis[(3,5-dimethoxybenzyloxy)benzyloxy]benzylsulfanyl) were exposed to visible and ultraviolet radiation (UV A + B + C) in order to determine their photochemical properties. The course of photochemical reactions in dimethylformamide solutions and the ability of the systems to generate singlet oxygen were studied by UV-Vis spectroscopy, which additionally gave information on aggregation processes...
February 21, 2018: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/29446095/orobanche-cernua-loefling-attenuates-ultraviolet-b-mediated-photoaging-in-human-dermal-fibroblasts
#9
Wei Gao, Yu-Shuai Wang, Zheng-Yi Qu, Eunson Hwang, Hien T T Ngo, Ying-Ping Wang, Jahyun Bae, Tae-Hoo Yi
UV radiation is the primary cause of skin photoaging, which results in an increase in matrix metalloproteinases and degradation of collagen. Developing new natural antioxidant as photoprotective agents have become a popular area of research. Orobanche cernua Loefling is a parasitic plant that is rich in phenylethanoid glycosides (PhGs). This study investigated the photoprotective effects of the ethanolic extract of Orobanche cernua Loefling (OC) and its principal component acteoside on UVB-induced photoaging as well as their underlying molecular mechanisms in normal human dermal fibroblasts (NHDFs)...
February 15, 2018: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/29441672/role-of-solid-lipid-nanoparticles-as-photoprotective-agents-in-cosmetics
#10
REVIEW
Jobin Jose, Gladyston Netto
BACKGROUND: Novel drug delivery systems have gained popularity since last two decades because of its advantages over conventional dosage forms. Effect of UV radiation on skin can cause either acute or chronic damage to our skin. Solid lipid nanoparticles (SLNs) were developed as novel carrier over the conventional carrier systems like liposomes and emulsions. The SLNs were selected as a carrier for the formulation because of its ability to protect the labile drug particles, the ability to make the drug release in a controlled manner, and occlusive property of the SLNs...
February 13, 2018: Journal of Cosmetic Dermatology
https://www.readbyqxmd.com/read/29368845/cutaneous-lupus-erythematosus-clinico-pathologic-correlation
#11
Raffaele Filotico, Valentina Mastrandrea
Cutaneous lupus erythematosus (CLE) is a chronic-relapsing disease. It is defined as a LE localized to the skin without any significant systemic symptoms. Its annual incidence is of 4 cases per 100,000 persons with a prevalence of 73 cases per 100,000 persons. The etiology is unknown but it is considered as a prototype of autoimmune disease in which genetic factors (HLA), environmental factors (photo exposure and cigarette smoking) and pharmacological agents play an important role. The most accepted classification includes three clinical variants: acute (ACLE), subacute (SCLE) and chronic (CCLE)...
January 24, 2018: Giornale Italiano di Dermatologia e Venereologia: Organo Ufficiale, Società Italiana di Dermatologia e Sifilografia
https://www.readbyqxmd.com/read/29318654/modification-of-the-fitzpatrick-system-of-skin-phototype-classification-for-the-indian-population-and-its-correlation-with-narrowband-diffuse-reflectance-spectrophotometry
#12
V K Sharma, V Gupta, B L Jangid, M Pathak
BACKGROUND: The Fitzpatrick classification for skin phototyping is widely used, but its usefulness in dark-skinned populations has been questioned by some researchers. Recently, skin colour measurement has been proposed for phototyping skin colour objectively. AIMS: To modify the Fitzpatrick system of skin phototyping for the Indian population and to study its correlation with skin colour using narrowband diffuse reflectance spectrophotometry METHODS: Answer choices for three items (eye colour, hair colour, colour of unexposed skin) out of 10 in the original Fitzpatrick questionnaire were modified, followed by self-administration of the original and the modified Fitzpatrick questionnaire by 70 healthy Indian volunteers...
April 2018: Clinical and Experimental Dermatology
https://www.readbyqxmd.com/read/29318223/investigating-isomer-specific-photoprotection-in-a-model-plant-sunscreen
#13
M D Horbury, A L Flourat, S E Greenough, F Allais, V G Stavros
Sinapate esters are used throughout the plant kingdom, for example in photoprotection from ultraviolet radiation. Sinapate esters are naturally produced in their E-isomeric form; however, upon exposure to ultraviolet radiation, photoisomerization drives Z-isomer formation. To elucidate the photoprotection capacity of E vs. Z forms of sinapate esters, we explore the photochemistry of the model system, Z-ethyl sinapate. Following a novel Z-ethyl sinapate synthesis, we demonstrate that photoprotection is isomer independent...
January 23, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29303960/lhcsr-expression-under-hsp70-rbcs2-promoter-as-a-strategy-to-increase-productivity-in-microalgae
#14
Federico Perozeni, Giulio Rocco Stella, Matteo Ballottari
Microalgae are unicellular photosynthetic organisms considered as potential alternative sources for biomass, biofuels or high value products. However, limited biomass productivity is commonly experienced in their cultivating system despite their high potential. One of the reasons for this limitation is the high thermal dissipation of the light absorbed by the outer layers of the cultures exposed to high light caused by the activation of a photoprotective mechanism called non-photochemical quenching (NPQ). In the model organism for green algae Chlamydomonas reinhardtii , NPQ is triggered by pigment binding proteins called light-harvesting-complexes-stress-related (LHCSRs), which are over-accumulated in high light...
January 5, 2018: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/29300935/genetic-basis-of-photosynthetic-responses-to-cold-in-two-locally-adapted-populations-of-arabidopsis-thaliana
#15
Christopher G Oakley, Linda Savage, Samuel Lotz, G Rudd Larson, Michael F Thomashow, David M Kramer, Douglas W Schemske
Local adaptation is common, but the traits and genes involved are often unknown. Physiological responses to cold probably contribute to local adaptation in wide-ranging species, but the genetic basis underlying natural variation in these traits has rarely been studied. Using a recombinant inbred (495 lines) mapping population from locally adapted populations of Arabidopsis thaliana from Sweden and Italy, we grew plants at low temperature and mapped quantitative trait loci (QTLs) for traits related to photosynthesis: maximal quantum efficiency (Fv/Fm), rapidly reversible photoprotection (NPQfast), and photoinhibition of PSII (NPQslow) using high-throughput, whole-plant measures of chlorophyll fluorescence...
January 23, 2018: Journal of Experimental Botany
https://www.readbyqxmd.com/read/29258247/targeting-nrf2-for-improved-skin-barrier-function-and-photoprotection-focus-on-the-achiote-derived-apocarotenoid-bixin
#16
REVIEW
Montserrat Rojo de la Vega, Andrea Krajisnik, Donna D Zhang, Georg T Wondrak
The transcription factor NRF2 (nuclear factor-E2-related factor 2) orchestrates major cellular defense mechanisms including phase-II detoxification, inflammatory signaling, DNA repair, and antioxidant response. Recent studies strongly suggest a protective role of NRF2-mediated gene expression in the suppression of cutaneous photodamage induced by solar UV (ultraviolet) radiation. The apocarotenoid bixin, a Food and Drug Administration (FDA)-approved natural food colorant (referred to as 'annatto') originates from the seeds of the achiote tree native to tropical America, consumed by humans since ancient times...
December 18, 2017: Nutrients
https://www.readbyqxmd.com/read/29240311/systemic-changes-in-photosynthesis-and-reactive-oxygen-species-homeostasis-in-shoots-of-arabidopsis-thaliana-infected-with-the-beet-cyst-nematode-heterodera-schachtii
#17
Mateusz Labudda, Elżbieta Różańska, Weronika Czarnocka, Mirosław Sobczak, Jolanta Maria Dzik
Photosynthetic efficiency and redox homeostasis are important for plant physiological processes during regular development as well as defence responses. The second-stage juveniles of Heterodera schachtii induce syncytial feeding sites in host roots. To ascertain whether the development of syncytia alters photosynthesis and the metabolism of reactive oxygen species (ROS), chlorophyll a fluorescence measurements and antioxidant responses were studied in Arabidopsis thaliana shoots on the day of inoculation and at 3, 7 and 15 days post-inoculation (dpi)...
December 14, 2017: Molecular Plant Pathology
https://www.readbyqxmd.com/read/29154200/uvr-and-par-absorbing-compounds-of-marine-brown-macroalgae-along-a-latitudinal-gradient-of-the-brazilian-coast
#18
Caroline Schmitz, Fernanda Ramlov, Leidson Allan Ferreira de Lucena, Virgilio Uarrota, Manuela Bernardes Batista, Marina Nasri Sissini, Iara Oliveira, Bruno Briani, Cintia D L Martins, José Marcos de Castro Nunes, Leonardo Rörig, Paulo Antunes Horta, Félix L Figueroa, Nathalie Korbee, Marcelo Maraschin, José Bonomi-Barufi
Absorption spectra are indicative of biological sample chemical composition and can be used as a basis for the construction of descriptive and predictive models for biotechnological screening or assays. In marine algae, chemical composition can vary due to species-specific differences in biochemistry, as well as intra-specific responses to unique environmental variables. Different indices (UVC i, UVB+A i and PARi) were proposed and calculated to evaluate how photoprotective compounds vary in 18 species of Phaeophyceae...
January 2018: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/29124692/ultraviolet-radiations-skin-defense-damage-mechanism
#19
Dheeraj Mohania, Shikha Chandel, Parveen Kumar, Vivek Verma, Kumar Digvijay, Deepika Tripathi, Khushboo Choudhury, Sandeep Kumar Mitten, Dilip Shah
UV-radiations are the invisible part of light spectra having a wavelength between visible rays and X-rays. Based on wavelength, UV rays are subdivided into UV-A (320-400 nm), UV-B (280-320 nm) and UV-C (200-280 nm). Ultraviolet rays can have both harmful and beneficial effects. UV-C has the property of ionization thus acting as a strong mutagen, which can cause immune-mediated disease and cancer in adverse cases. Numbers of genetic factors have been identified in human involved in inducing skin cancer from UV-radiations...
2017: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/29119916/cytoprotective-polyphenols-against-chronological-skin-aging-and-cutaneous-photodamage
#20
Sergio Davinelli, Juan Carlos Bertoglio, Ascanio Polimeni, Giovanni Scapagnini
BACKGROUND: Skin aging is a complex biological process influenced by a combination of intrinsic and extrinsic factors, leading to cumulative alterations of skin structure, function and appearance. Polyphenols, which are secondary plant metabolites, represent one of the largest classes of compounds used in dermatology and nutricosmetics to combat skin aging. The main objective is to provide an overview of the existing literature linking skin aging and the ability of polyphenols as regulatory elements able to maintain skin homeostasis...
November 8, 2017: Current Pharmaceutical Design
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