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Systemic photoprotection

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
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
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
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
Marilena Di Valentin, Maria Giulia Dal Farra, Laura Galazzo, Marco Albertini, Tim Schulte, Eckhard Hofmann, Donatella Carbonera
Triplet-triplet energy transfer from chlorophylls to carotenoids is the mechanism underlying the photoprotective role played by carotenoids in many light harvesting complexes, during photosynthesis. The peridinin-chlorophyll-a protein (PCP) is a water-soluble light harvesting protein of the dinoflagellate Amphidinium carterae, employing peridinin as the main carotenoid to fulfil this function. The dipolar coupling of the triplet state of peridinin, populated under light excitation in isolated PCP, to the MTSSL nitroxide, introduced in the protein by site-directed mutagenesis followed by spin labeling, has been measured by Pulse ELectron-electron DOuble Resonance (PELDOR) spectroscopy...
September 20, 2016: Biochimica et Biophysica Acta
Zhengwang Sun, Sang Yong Park, Eunson Hwang, Mengyang Zhang, Seul A Seo, Pei Lin, Tae-Hoo Yi
Solar ultraviolet (UV) radiation-induced reactive oxidative species is mainly responsible for the development of photoageing. Rosmarinic acid was one of the main bioactive components detected in Thymus vulgaris (TV) we extracted. In this study, UVB-induced skin damages have been shown to be ameliorated by treatment with TV in hairless mice (HR-1) skin, demonstrated by decreased matrix metalloproteinases (MMPs) and increased collagen production. However, the underlying molecular mechanism on which TV acted was unclear...
September 19, 2016: Journal of Cellular and Molecular Medicine
Ian Pahk, Gerdenis Kodis, Graham R Fleming, Thomas A Moore, Ana L Moore, Devens Gust
Nonphotochemical quenching (NPQ) is a photoprotective regulatory mechanism employed by many photosynthetic organisms to dynamically modulate energy flow within the photosynthetic apparatus in response to fluctuating light conditions. Activated by decreases in lumen pH produced during periods of high photon flux, NPQ induces rapid thermal dissipation of excess excitation energy. As a result, the rate of charge separation (CS) decreases, thereby limiting the accumulation of potentially deleterious reactive intermediates and byproducts...
October 4, 2016: Journal of Physical Chemistry. B
Daniel L Jones, Bonnie K Baxter
Halophilic archaea experience high levels of ultraviolet (UV) light in their environments and demonstrate resistance to UV irradiation. DNA repair systems and carotenoids provide UV protection but do not account for the high resistance observed. Herein, we consider genomic signatures as an additional photoprotective strategy. The predominant forms of UV-induced DNA damage are cyclobutane pyrimidine dimers, most notoriously thymine dimers (T^Ts), which form at adjacent Ts. We tested whether the high G + C content seen in halophilic archaea serves a photoprotective function through limiting T nucleotides, and thus T^T lesions...
September 2, 2016: Life
Federico Gonzalez-Fernandez, Brandi Betts-Obregon, Andrew T Tsin, Richard J DeSa
PURPOSE: Assaying photodecomposition is challenging because light must be used to initiate the photodamage and light must be used to monitor the photodecomposition. The experimental requirements are as follows: 1) During exposure of the actinic beam, continuously monitor the spectral characteristics of the sample, 2) uniformly expose the reactants to the actinic source, 3) obtain informative spectra in the presence of light scatter, and 4) achieve sufficient sensitivity for dilute reactants...
2016: Molecular Vision
D Skiljevic, B Bonaci-Nikolic, D Brasanac, M Nikolic
BACKGROUND: Dysregulation of apoptosis has an important role in the induction of autoimmunity. OBJECTIVE: To evaluate the influence of keratinocyte apoptosis and deoxyribonuclease I (DNase I) activity on the clinical and immunoserological parameters of cutaneous lupus erythematosus (CLE). METHODS: We studied 69 CLE patients (39 with discoid LE (DLE), 12 with subacute CLE (SCLE), 12 with acute and 6 with intermittent CLE). 30/69 patients fulfilled criteria for systemic LE (SLE)...
August 24, 2016: Journal of the European Academy of Dermatology and Venereology: JEADV
Michal Gwizdala, Rudi Berera, Diana Kirilovsky, Rienk van Grondelle, Tjaart P J Krüger
When exposed to intense sunlight, all organisms performing oxygenic photosynthesis implement various photoprotective strategies to prevent potentially lethal photodamage. The rapidly responding photoprotective mechanisms, occurring in the light-harvesting pigment-protein antennae, take effect within tens of seconds, while the dramatic and potentially harmful light intensity fluctuations manifest also on shorter time scales. Here we show that, upon illumination, individual phycobilisomes from Synechocystis PCC 6803, which, in vivo under low-light conditions, harvest solar energy, and have the built-in capacity to switch rapidly and reversibly into light-activated energy-dissipating states...
September 14, 2016: Journal of the American Chemical Society
Hideki Hashimoto, Chiasa Uragami, Richard J Cogdell
Carotenoids are ubiquitous and essential pigments in photosynthesis. They absorb in the blue-green region of the solar spectrum and transfer the absorbed energy to (bacterio-)chlorophylls, and so expand the wavelength range of light that is able to drive photosynthesis. This is an example of singlet-singlet energy transfer, and so carotenoids serve to enhance the overall efficiency of photosynthetic light reactions. Carotenoids also act to protect photosynthetic organisms from the harmful effects of excess exposure to light...
2016: Sub-cellular Biochemistry
Kuk-Youn Ju, Jeeun Kang, Jin Ho Chang, Jin-Kyu Lee
The contradictory biological function of eumelanin (photoprotection vs photosensitization) has long been a topic of debate in a wide range of disciplines such as chemistry, physics and biology. For understanding full spectrum of eumelanin's photobiological aspect, revealing how eumelanin's complex structural organization dictates its photophysical properties is critical step. Here, we report a practical approach to controlling the hierarchically assembled structure of natural eumelanin, which leads to disassembly of its structure into subunits and oxidized subunits, respectively...
September 12, 2016: Biomacromolecules
I M Kornilovsky, A I Sultanova, A A Burtsev
UNLABELLED: Photorefractive ablation is inevitably accompanied by oxidative stress of the cornea and weakening of its biomechanical and photoprotective properties. AIM: To validate the expediency of riboflavin use in photorefractive ablation for photoprotection of the cornea and cross-linking. MATERIAL AND METHODS: The effects of riboflavin use in photorefractive ablation was first studied in a series of in vitro and in vivo experiments performed on 56 eyes of 28 rabbits, and then on 232 eyes of 142 patients with different degrees of myopia...
May 2016: Vestnik Oftalmologii
Julia Weber, Nadine L Funk, Mariana H Motta, Alessandra M Guedes, Ana Paula C Visintainer, Solange B Tedesco, Cristiane de B Da Silva
The association of vegetable products to nanostructured systems has attracted the attention of researchers due to several advantages, such as drug photoprotection, as well as the improvement of the pharmacological and therapeutic activities because of synergistic action, which can provide their topical application. In this work, lipid-core nanocapsules containing borage oil as oil core and betamethasone dipropionate were developed, and nanocapsules without the drug were prepared for comparison. The suspensions were characterized in relation to mean particle size, zeta potential, pH, drug content, and encapsulation efficiency...
February 2016: Journal of Nanoscience and Nanotechnology
Concepcion Parrado, Marta Mascaraque, Yolanda Gilaberte, Angeles Juarranz, Salvador Gonzalez
Healthier life styles include increased outdoors time practicing sports and walking. This means increased exposure to the sun, leading to higher risk of sunburn, photoaging and skin cancer. In addition to topical barrier products, oral supplementations of various botanicals endowed with antioxidant activity are emerging as novel method of photoprotection. Polypodium leucotomos extract (PL, commercial name Fernblock(®), IFC Group, Spain) is a powerful antioxidant due to its high content of phenolic compounds...
2016: International Journal of Molecular Sciences
Stefano Cazzaniga, Mauro Bressan, Donatella Carbonera, Alessandro Agostini, Luca Dall'Osto
Carotenes and their oxygenated derivatives, xanthophylls, are structural elements of the photosynthetic apparatus and contribute to increasing both the light-harvesting and photoprotective capacity of the photosystems. β-Carotene is present in both the core complexes and light-harvesting system (LHCI) of Photosystem (PS) I, while xanthophylls lutein and violaxanthin bind exclusively to its antenna moiety; another xanthophyll, zeaxanthin, which protects chloroplasts against photooxidative damage, binds to the LHCI complexes under conditions of excess light...
July 5, 2016: Biochemistry
Maya Valeska Gozali, Bing-Rong Zhou, Dan Luo
Photodermatoses are a group of skin conditions associated with an abnormal reaction to ultraviolet (UV) radiation. There are several of the photosensitive rashes which mainly affect the UV exposed areas of the skin. It can be classified into four groups: immunology mediated photodermatoses, chemical and drug induced photosensitivity, photoaggravated dermatoses, and genetic disorders. A systematic approach including history, physical examination, phototesting, photopatch testing, and laboratory tests are important in diagnosis of a photodermatosis patient...
2016: Dermatology Online Journal
María Victoria Salomon, Rebeca Purpora, Rubén Bottini, Patricia Piccoli
It has been proposed that plant growth promoting rhizobacteria (PGPR) stimulate plant growth and development by inducing the biosynthesis of secondary metabolites, like terpenes, which reduce stress incidence. Three bacteria previously isolated from grapevine roots and adjacent soil (Microbacterium imperiale Rz19M10, Kocuria erythromyxa Rt5M10 and Terribacillus saccharophilus Rt17M10) were tested as PGPR. After 30 days since root inoculation of in vitro grown Vitis vinifera cv. Malbec plants, the monoterpenes α-pinene, terpinolene and 4-carene, and the sesquiterpene nerolidol were detected only in bacterized-plant leaves...
September 2016: Plant Physiology and Biochemistry: PPB
Daniela C Vinhal, Renato Ivan de Ávila, Marcelo S Vieira, Rangel M Luzin, Michelle P Quintino, Liliane M Nunes, Antonio Carlos Chaves Ribeiro, Henrique Santiago de Camargo, Angelo C Pinto, Helvécio M Dos Santos Júnior, Bruna G Chiari, Vera Isaac, Marize C Valadares, Tatiana Duque Martins, Luciano M Lião, Eric de S Gil, Ricardo Menegatti
The new heterocyclic derivative LQFM048 (3) (2,4,6-tris ((E)-ethyl 2-cyano-3-(4-hydroxy-3-methoxyphenyl)acrylate)-1,3,5-triazine) was originally designed through the molecular hybridization strategy from Uvinul® T 150 (1) and (E)-ethyl 2-cyano-3-(4hydroxy-3-methoxyphenyl)acrylate (2) sunscreens, using green chemistry approach. This compound was obtained in global yields (80%) and showed an interesting redox potential. In addition, it is thermally stable up to temperatures around 250°C. It was observed that LQFM048 (3) showed a low degradation after 150min of sunlight exposure at 39°C, whereas the extreme radiation conditions induced a considerable photodegradation of the LQFM048 (3), especially when irradiated by VIS and VIS+UVA...
August 2016: Journal of Photochemistry and Photobiology. B, Biology
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