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Wei Huang, Ying-Jie Yang, Hong Hu, Shi-Bao Zhang
Low temperature associated with high light can induce photoinhibition of photosystem I (PSI) and photosystem II (PSII). However, the photosynthetic electron flow and specific photoprotective responses in alpine evergreen broad-leaf plants in winter is unclear. We analyzed seasonal changes in PSI and PSII activities, and energy quenching in PSI and PSII in three alpine broad-leaf tree species, Quercus guyavifolia (Fagaceae), Rhododendron decorum (Ericaceae), Euonymus tingens (Celastraceae). In winter, PSII activity remained stable in Q...
October 13, 2016: Journal of Photochemistry and Photobiology. B, Biology
Zhengwang Sun, Sang Yong Park, Eunson Hwang, Bom Park, Seul A Seo, Jin-Gyeong Cho, Mengyang Zhang, Tae-Hoo Yi
BACKGROUND: Foeniculum vulgare Mill (FV) has long been prescribed in traditional medicine due to its antioxidant anti-inflammatory properties. However, little research has been done on the use of FV to alleviate changes in UVB-induced photoaging PURPOSE: This study was to investigate the photoprotective effects and mechanism of FV in vitro and in vivo. METHODS: The anti-photoaging effect of FV was assessed in normal human dermal fibroblasts (NHDFs) in vitro. The secretion of reactive oxygen species (ROS), lactate dehydrogenase (LDH), GSH, matrix metalloproteinases (MMPs), procollagen type I, IL-6 and transforming growth factor-β1 (TGF-β1) were measured by kits...
November 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Bice S Martincigh, Moses A Ollengo
The photostabilizing ability of grape seed extract on three common sunscreen absorbers: 2-ethylhexyl-p-methoxcinnamate (EHMC), benzophenone-3 (BP3) and tert-butylmethoxy dibenzoylmethane (BMDBM), was investigated. Samples were exposed to simulated solar radiation and monitored by spectrophotometric and chromatographic methods. The chemical composition of the grape seed extract was determined by GC-MS and HPLC-MS and the major secondary metabolites were found to be epicatechin and catechin. Exposure of the extract to UV radiation increased the UV absorption capacity of the extract...
October 19, 2016: Photochemistry and Photobiology
Marta Pintó-Marijuan, Alba Cotado, Eva Fleta-Soriano, Sergi Munné-Bosch
Plants are known for their high capacity to acclimatise to fluctuating environmental conditions. A wide range of environmental conditions can lead to suboptimal physiological efficiency. However, recent studies have shown that plants can withstand repeated periods of stress. To find out how they do it, we studied photosynthetic adjustments to repeated water stress in Aptenia cordifolia: a facultative, invasive CAM species. Plants were subjected to three cycles of water deficit, and photosynthetic parameters and chloroplast antioxidants were quantified to gain an understanding of the mechanisms by which they cope with repeated stress periods...
October 18, 2016: Photosynthesis Research
Nikolai N Sluchanko, Konstantin E Klementiev, Evgeny A Shirshin, Georgy V Tsoraev, Thomas Friedrich, Eugene G Maksimov
In Cyanobacteria, the Orange Carotenoid Protein (OCP) and Fluorescence Recovery Protein (FRP) are central to the photoprotective mechanism consisting in regulated quenching of phycobilisome (PBs) fluorescence. Due to a transient and flexible nature of the light-activated red quenching form, OCP(R), which is obtained from the stable dark-adapted orange form, OCP(O), by photoconversion, the detailed mechanism of photoprotection remains unclear. Here we demonstrate that our recently described W288A mutant of the Synechocystis OCP (hereinafter called OCP(W288A)) is a fully functional analogue of the OCP(R) form which is capable of constitutive PBs fluorescence quenching in vitro with no need of photoactivation...
October 15, 2016: Biochimica et Biophysica Acta
Zi-Shan Zhang, Mei-Jun Liu, Renate Scheibe, Jennifer Selinski, Li-Tao Zhang, Cheng Yang, Xiang-Long Meng, Hui-Yuan Gao
The mechanism by which the mitochondrial alternative oxidase (AOX) pathway contributes to PSII photoprotection is in dispute. The current consensus is that the AOX pathway protects photosystems by dissipating excess reducing equivalents that are exported from chloroplasts through the malate/oxaloacetate (Mal/OAA) shuttle, preventing the over-reduction of chloroplasts. Here, using the aox1a Arabidopsis mutant and nine other C3 and C4 species, an additional model of the AOX pathway in PSII photoprotection is proposed...
October 13, 2016: Molecular Plant
Yik Weng Yew, Cerrene N Giordano, Graciela Spivak, Henry W Lim
Photodermatoses associated with defective DNA repair are a group of photosensitive hereditary skin disorders. In this review, we focus on diseases and syndromes with defective nucleotide excision repair that are not accompanied by an increased risk of cutaneous malignancies despite having photosensitivity. Specifically, the gene mutations and transcription defects, epidemiology, and clinical features of Cockayne syndrome, cerebro-oculo-facial-skeletal syndrome, ultraviolet-sensitive syndrome, and trichothiodystrophy will be discussed...
November 2016: Journal of the American Academy of Dermatology
Cerrene N Giordano, Yik Weng Yew, Graciela Spivak, Henry W Lim
Hereditary photodermatoses are a spectrum of rare photosensitive disorders that are often caused by genetic deficiency or malfunction of various components of the DNA repair pathway. This results clinically in extreme photosensitivity, with many syndromes exhibiting an increased risk of cutaneous malignancies. This review will focus specifically on the syndromes with malignant potential, including xeroderma pigmentosum, Bloom syndrome, and Rothmund-Thomson syndrome. The typical phenotypic findings of each disorder will be examined and contrasted, including noncutaneous identifiers to aid in diagnosis...
November 2016: Journal of the American Academy of Dermatology
Renata Ottes Vasconcelos, Silvina Odete Bustos, Juliana Ramos Gonzalez, Camila Wink Soares, Makely Daiane Barbosa, Roger Chammas, Ana Paula de Souza Votto, Gilma Santos Trindade
Omega 3 polyunsaturated fatty acids (omega 3 PUFA) are attracting a growing interest as potential adjuvants for cancer prevention and treatment. There is evidence about photoprotection in normal cells, but few previous studies have evaluated it in tumoral cells. Therefore, this study investigated the effect of α-linolenic acid (ALA) in normal murine melanocytic cells (Melan-a) and in tumoral murine melanocytic cells (B16F10) exposed to UVB radiation. Our results showed that ALA exhibited an antiproliferative effect in B16F10 cells, and had minimal effect in Melan-a cells, as demonstrated by MTT assay...
October 3, 2016: Journal of Photochemistry and Photobiology. B, Biology
Alexander H Fischer, Timothy S Wang, Gayane Yenokyan, Sewon Kang, Anna L Chien
Importance: Indoor tanning is prevalent among young adults and women and is associated with increased risk of melanoma. Evidence suggests that indoor tanners may be more inclined to adopt poor photoprotective practices that further increase their risk of skin cancer; however, gaps in the literature exist in young adults and by indoor tanning frequency. Objective: To examine the association between indoor tanning frequency and behaviors related to skin cancer prevention and to investigate whether these associations vary by age group or sex...
October 12, 2016: JAMA Dermatology
Pierre Çarçabal, Dominique Descamps, Stéphane Petit, Yann Mairesse, Valérie Blanchet, Raluca Cireasa
5-Fluorouracil (5FU) is a radiosensitiser molecule routinely used in combined chemo- and radio-therapies to enhance and localize cancer treatments. We have employed ultra-short XUV pulses produced by high harmonic generation (HHG) as a pump pulse to study the dynamics underlying the photo-stability and the radiation damage of this molecule. This work shows that it is possible to resolve individual dynamics even when using unselected HH. By comparing the results with those obtained in the multiphoton absorption at 400 nm, we were able to identify the frequencies of the HH comb relevant to the recorded dynamics: HH5 and HH3...
September 22, 2016: Faraday Discussions
Riham Gharib, Lizette Auezova, Catherine Charcosset, Hélène Greige-Gerges
A combined approach based on cyclodextrin/drug inclusion complex formation and loading into liposomes was applied to improve the effectiveness of liposome loading with essential oils. Hydroxypropyl-β-cyclodextrin/ANE (HP-β-CD/ANE) inclusion complexes were prepared and encapsulated into liposomes (ACL). ANE-double-loaded liposomes (ACL2) were obtained with the HP-β-CD/ANE complex in the aqueous phase and ANE in the organic phase. Liposomes were prepared from saturated (Phospholipon 90H) or unsaturated (Lipoid S100) phospholipids and characterized for size, polydispersity index, zeta potential, morphology, loading rate (LR) and photo- and storage stabilities...
March 1, 2017: Food Chemistry
Vipaporn Cheewinthamrongrod, Hakuto Kageyama, Tanapat Palaga, Teruhiro Takabe, Rungaroon Waditee-Sirisattha
Mycosporine-like amino acids (MAAs) are a group of natural sunscreen compounds that possess highly photoprotective properties. The most commonly found MAAs in marine organisms is shinorine, porphyra-334, and mycosporine-glycine. However, the halophilic species accumulate mycosporine-2-glycine (M2G) as the major MAA. In this study, we have investigated the protective effect of M2G against oxidative stress. In vitro radical scavenging activity revealed that M2G exhibited a significant inhibition with scavenging concentration (SC) 50 value of 22±1...
September 29, 2016: Journal of Photochemistry and Photobiology. B, Biology
Huaping Li, Na Jiang, Qing Liu, Aili Gao, Xin Zhou, Bihua Liang, Runxiang Li, Zhenjie Li, Huilan Zhu
Ultraviolet (UV) radiation causes skin injury and inflammation resulting in impaired immune response and increased risk of skin cancer. It has been shown that green tea polyphenols (GTPs) enhanced intracellular antioxidant defense and promoted the downregulation of proapoptotic genes, and they could be used to protect against the damage induced by UV irradiation. However, the high instability and poor bioavailability of GTPs impose restrictions on their potential pharmacological use. Here we show that carboxymethyl cellulose sodium (CMC-Na) had a stabilizing effect on GTPs under aqueous conditions and topical application of GTPs (emulsified in CMC-Na) had a strong photoprotective effect against acute UVB induced photodamage in uncovered (Uncv) hairless mice skin...
October 5, 2016: Photochemical & Photobiological Sciences
Mauro Commisso, Ketti Toffali, Pamela Strazzer, Matteo Stocchero, Stefania Ceoldo, Barbara Baldan, Marisa Levi, Flavia Guzzo
The phenylpropanoid and flavonoid families include thousands of specialized metabolites that influence a wide range of processes in plants, including seed dispersal, auxin transport, photoprotection, mechanical support and protection against insect herbivory. Such metabolites play a key role in the protection of plants against abiotic stress, in many cases through their well-known ability to inhibit the formation of reactive oxygen species (ROS). However, the precise role of specific phenylpropanoid and flavonoid molecules is unclear...
2016: Frontiers in Plant Science
Arianna Smerilli, Ida Orefice, Federico Corato, Antonio Gavalás Olea, Alexander V Ruban, Christophe Brunet
Photosynthesis is known to produce reactive oxygen species together with the transformation of light into biochemical energy. To fill the gap of the knowledge on the protective antioxidant network of microalgae, we performed a series of experiments to explore the role of spectral composition and intensity of light in the modulation of the photodefence mechanisms developed by the coastal diatom Skeletonema marinoi. We analysed the modulation of the total phenolic content, ascorbic acid, and the enzymes glutathione reductase, catalase, ascorbate peroxidase and superoxide dismutase together with xanthophyll cycle and non-photochemical quenching in response to variations in the light environment...
October 6, 2016: Environmental Microbiology
Yoann Peperstraete, Michael Staniforth, Lewis A Baker, Natércia D N Rodrigues, Neil C Cole-Filipiak, Wen-Dong Quan, Vasilios G Stavros
Methyl-E-4-methoxycinnamate (E-MMC) is a model chromophore of the commonly used commercial sunscreen agent, 2-ethylhexyl-E-4-methoxycinnamate (E-EHMC). In an effort to garner a molecular-level understanding of the photoprotection mechanisms in operation with E-EHMC, we have used time-resolved pump-probe spectroscopy to explore E-MMC's and E-EHMC's excited state dynamics upon UV-B photoexcitation to the S1 (1(1)ππ*) state in both the gas- and solution-phase. In the gas-phase, our studies suggest that the excited state dynamics are driven by non-radiative decay from the 1(1)ππ* to the S3 (1(1)nπ*) state, followed by de-excitation from the 1(1)nπ* to the ground electronic state (S0)...
October 12, 2016: Physical Chemistry Chemical Physics: PCCP
Tandeka Magcwebeba, Pieter Swart, Sonja Swanevelder, Elizabeth Joubert, Wentzel Gelderblom
Ultraviolet B (UVB) radiation is one of the major predisposing risk factors of skin cancer. The anticancer and photoprotective effects of unoxidized rooibos (Aspalathus linearis) and honeybush (Cyclopia) herbal teas, containing high levels of dihydrochalones and xanthones, respectively, have been demonstrated in skin cancer models in vivo. In the current study, the anti-inflammatory effects of methanol and aqueous extracts of these herbal teas were investigated in a UVB/HaCaT keratinocyte model with intracellular interleukin-1α (icIL-1α) accumulation as a biomarker...
October 2, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Yi Xiao, Danny Tholen, Xin-Guang Zhu
Leaf photosynthesis is determined by biochemical properties and anatomical features. Here we developed a three-dimensional leaf model that can be used to evaluate the internal light environment of a leaf and its implications for whole-leaf electron transport rates (J). This model includes (i) the basic components of a leaf, such as the epidermis, palisade and spongy tissues, as well as the physical dimensions and arrangements of cell walls, vacuoles and chloroplasts; and (ii) an efficient forward ray-tracing algorithm, predicting the internal light environment for light of wavelengths between 400 and 2500nm...
October 4, 2016: Journal of Experimental Botany
Yazhe Wang, Cheng Wang, Yang Ding, Jing Li, Min Li, Xiao Liang, Jianping Zhou, Wei Wang
Photodynamic therapy has emerged as a promising strategy for cancer treatment. To ensure the efficient delivery of a photosensitizer to tumor for anticancer effect, a safe and tumor-specific delivery system is highly desirable. Herein, we introduce a novel biomimetic nanoparticle named rHDL/ICG (rHDL/I), by loading amphiphilic near-infrared (NIR) fluorescent dye indocyanine green (ICG) into reconstituted high density lipoproteins (rHDL). In this system, rHDL can mediate photoprotection effect and receptor-guided tumor-targeting transportation of cargos into cells...
September 26, 2016: Colloids and Surfaces. B, Biointerfaces
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