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Photochemistry and Photobiology

Sandeep C Chaudhary, Mohammad Waseem, Mehtab Rana, Hui Xu, Levy Kopelovich, Craig A Elmets, Mohammad Athar
Naproxen possesses anti-proliferative and pro-apoptotic effects besides its known anti-inflammatory functions. Here, we demonstrate the anti-cancer effects of naproxen against UVB-induced BCCs and SCCs in a highly susceptible murine model of UVB carcinogenesis. Naproxen significantly inhibited UVB-induced BCCs and SCCs in this model. Tumor number and volume were significantly decreased (p<0.005 and p<0.05, respectively). Inhibition in UVB-induced SCCs and BCCs was 77% and 86%, respectively, which was associated with reduced PCNA and cyclin D1 and increased apoptosis...
March 22, 2017: Photochemistry and Photobiology
Alena Rajnochová Svobodová, Alena Ryšavá, Michaela Psotová, Pavel Kosina, Bohumil Zálešák, Jitka Ulrichová, Jitka Vostálová
Quercetin, one of the most abundant polyphenols in the plant kingdom has been shown to be photodegraded on exposure to UV light. Despite the fact, it is a component of several dermatological preparations. Its phototoxic potential has not been evaluated to date. The aim of this study was to assess whether photo-induced degradation of quercetin is linked to phototoxic effects on living cells. Its dihydro derivative, taxifolin was included in the study. For evaluation, the 3T3 Neutral Red Uptake Phototoxicity Test according to OECD TG 432, was used...
March 16, 2017: Photochemistry and Photobiology
Gregory T Carroll, Nicholas J Turro, Angela Mammana, Jeffrey T Koberstein
In this manuscript we demonstrate the control of film thickness and surface wettability in the photochemical immobilization of poly (vinyl alcohol) (PVA) to a self-assembled monolayer (SAM) containing a phthalimide chromophore. Surface attachment is characterized by ellipsometry and contact angle measurements. The wettability of the resulting films is shown to depend on the chemical composition of the polymer. The film thickness is shown to depend on the irradiation time and molecular weight of the polymer...
March 15, 2017: Photochemistry and Photobiology
Nana Kinoshita, Chikako Nagasato, Taizo Motomura
Brown algal swarmers usually exhibit positive or negative phototaxis. Such behaviours influence the increasing or decreasing dispersal distance or colonization on the new substratum. We confirmed that the sign of phototaxis (negative or positive) in male gametes of Mutimo cylindricus was affected by extracellular Ca(2+) influx through Ca(2+) channels. Under the control condition (10(-2) M [Ca(2+) ]), male gametes swimming with a helical rotation of their cell body mostly showed positive phototaxis. At 10(-3) M [Ca(2+) ], more than half of the male gametes showed positive phototaxis, whereas the others showed negative phototaxis...
March 15, 2017: Photochemistry and Photobiology
Gagan Chhabra, Mary Ann Ndiaye, Liz Mariely Garcia-Peterson, Nihal Ahmad
The incidence of skin cancers, both non-melanoma as well as melanoma, are increasing in the United States. The ultraviolet radiation, mainly from sun, is considered the major cause for these neoplasms. While non-melanoma skin cancers are far more numerous, melanoma remains the most challenging. This is because melanoma can become extremely aggressive and its incidence is increasing worldwide due to lack of effective early detection, as well as disease recurrence, following both surgery and chemotherapy. Therefore, in addition to better treatment options, newer means are required to prevent melanomas from developing...
March 15, 2017: Photochemistry and Photobiology
MiaoJian Wan, Rong Hu, Xiaoyuan Xie, Zijian Gong, Jinling Yi, Haiyan Chen, Lin Xie, Xiaomin Guan, Lei Guan, Wei Lai
Although there have been some studies about changes of skin erythema and pigmentation following ultraviolet radiation in other races, the relevant data in Chinese have never been achieved. Thus we evaluated the long-time course of skin erythema, pigmentation and hydration changes after different doses of solar-simulated ultraviolet (SSUV) irradiation in 26 Chinese women for 168 days. The erythema index increased abruptly and peaked during 3 days of SSUV exposure, then slowly returned to the baseline level starting at day 7 and completely recovered during 168-day course of this study only in one minimal erythema doses (MED) SSUV irradiation...
March 15, 2017: Photochemistry and Photobiology
Fengjun Zhang, Shuang Zou, Tianye Wang, Yuxi Shi, Peng Liu
CeO2 /Bi2 WO6 heterostructured microsphere with excellent and stable photocatalytic activity for degradation tetracyclines were successfully synthesized via a facile solvothermal route. The photocatalytic experiments indicated that CeO2 /Bi2 WO6 heterostructured microspheres exhibited enhanced photocatalytic activity compared to pure Bi2 WO6 in both the degradation of Tetracycline hydrochloride (TCH) and Rhodamine B (RhB) under visible-light irradiation. The 1CeO2 /2Bi2 WO6 exhibited the best photocatalytic activity for degradation of TCH, reaching 91% after 60min reaction...
March 6, 2017: Photochemistry and Photobiology
Shanmugaraj Krishnamoorthy, Umadevi Palanivel, Senthilkumar Lakshmipathi, Ilanchelian Malaichamy
The nature of binding mechanism of toluidine blue O (TBO) with chicken egg white lysozyme was studied comprehensively by various spectroscopic and computational methods. Both steady state and time resolved fluorescence studies unambiguously point to the prevalence of static quenching mechanism in lysozyme-TBO system. Thermodynamic parameters revealed that the association of TBO with lysozyme was a spontaneous process in which hydrophobic and hydrogen bond interactions played a pivotal role in the binding process...
March 1, 2017: Photochemistry and Photobiology
Tianye Wang, Shuang Zhong, Shuang Zou, Fuhuan Jiang, Limin Feng, Xiaosi Su
Novel Bi2 WO6 coupled Fe3 O4 magnetic photocatalysts with excellent and stable photocatalytic activity for degrading tetracycline hydrochloride and RhB were successfully synthesized via a facile solvothermal route. Through the characterization of the as-prepared magnetic photocatalysts by XRD, SEM, TEM, XPS, UV-vis diffuse reflectance spectra, it was found that the as-prepared magnetic photocatalysts were synthesized by the coupling of Bi2 WO6 and Fe3 O4 , and introduction of appropriated Fe3 O4 can improved nanospheres morphology and visible-light response...
February 15, 2017: Photochemistry and Photobiology
Irena Maliszewska, Barbara Lisiak, Katarzyna Popko, Katarzyna Matczyszyn
This study reports on successful photodynamic inactivation of planktonic and biofilm cells of Candida albicans using Rose Bengal (RB) in combination with biogenic gold nanoparticles synthesized by the cell-free filtrate of Penicillium funiculosum BL1 strain. Monodispersed colloidal gold nanoparticles coated with proteins were characterized by a number of techniques including SEM-EDS, TEM, UV-Vis absorption and fluorescence spectroscopy, as well as Fourier transform infrared spectroscopy to be 24±3 nm spheres coated with proteins...
February 12, 2017: Photochemistry and Photobiology
Nathalia Quintero Ruiz, Yuri Cordoba Campo, Elena E Stashenko, Jorge Luis Fuentes
The antigenotoxicity against ultraviolet radiation (UV) -induced DNA damage of essential oils (EO) from Lippia species was studied using SOS Chromotest. Based on the minimum concentration that significantly inhibits genotoxicity, the genoprotective potential of EO from highest to lowest was L. alba, citral -rich chemotype (RC) > L. graveolens, thymol-RC ≈ L. origanoides, thymol-RC ≈ L. origanoides, carvacrol-RC > L. micromera, thymol-RC ≈ L. citriodora, citral-RC > L. alba, myrcenone-RC > L...
February 8, 2017: Photochemistry and Photobiology
Mary D Boudreau, Frederick A Beland, Robert P Felton, Peter P Fu, Paul C Howard, Paul W Mellick, Brett T Thorn, Greg R Olson
Cosmetic products that contain retinyl palmitate are popular as anti-aging skin treatments; however, recent studies suggest a risk for enhanced skin tumor development with topical retinyl palmitate applications and exposure to solar ultraviolet radiation (UVR). In this study, we investigated the potential of retinyl palmitate to enhance UVR-induced photo co-carcinogenesis. Groups of 36 male and 36 female SKH-1 hairless mice were exposed to simulated solar light (SSL) and treated with the control cream or creams containing retinyl palmitate, five days per week for 40 weeks...
January 28, 2017: Photochemistry and Photobiology
Israr Ahmad, Kashiff M Muneer, Michelle E Chang, Hana M Nasr, Jacqueline M Clay, Conway C Huang, Nabiha Yusuf
Basal cell carcinomas (BCCs) account for majority of skin malignancies in the United States. The incidence of BCCs is strongly associated with exposure of ultraviolet (UV) radiation. Nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3 (NLRP3) inflammasome plays an important role in innate immune responses. Different stimuli such as toxins, microorganisms, and particles released from injured cells activate the NLRP3 inflammasome. Activated NLRP3 results in activation of caspase-1, which cleaves pro-IL-1β to active IL-1β...
January 25, 2017: Photochemistry and Photobiology
Arpit Dheeraj, Cynthia M Rigby, Cindy L O'Bryant, Chapla Agarwal, Rana P Singh, Gagan Deep, Rajesh Agarwal
Basal cell carcinoma (BCC) is the most common skin malignancy. Deregulated hedgehog signaling plays a central role in BCC development; therefore hedgehog inhibitors have been approved to treat locally advanced or metastatic BCC. However, the development of resistance to hedgehog inhibitors is the major challenge in effective treatment of this disease. Herein, we evaluated the efficacy of a natural agent silibinin to overcome resistance with hedgehog inhibitors (Sant-1 and GDC-0449) in BCC cells. Silibinin (25-100 μM) treatment for 48 hrs strongly inhibited growth and induced death in ASZ001, Sant-1 resistant (ASZ001-Sant-1) and GDC-0449 resistant (ASZ001-GDC-0449) BCC cells...
January 25, 2017: Photochemistry and Photobiology
Xi Peng, Jie Yang, Yang Gao
UV-C's effects on the physiological and biochemical processes of cyanobacteria have been well characterized. However, the molecular mechanisms of cyanobacteria's tolerance to UV-C still needs further investigation. This research attempts to decode the variation in protein abundances in cyanobacteria after UV-C stress. Different expression levels of proteins in the cytoplasm of Synechococcus sp. PCC7942 under UV-C stress were investigated by using a comparative proteomic approach. Forty-seven UV-C-regulated proteins were identified by MALDI-TOF analysis and classified by Gene Ontology (GO)...
January 25, 2017: Photochemistry and Photobiology
Sebastian Sinnecker, Wolfgang Lubitz
In reaction centers (RCs) of photosynthesis a light-induced charge separation takes place creating radical cations and anions of the participating cofactors. In photosynthetic bacteria different bacteriochlorophylls (BChl) are involved in this process. Information about the electronic structure of the BChl radical cations and anions can be obtained by measuring the electron spin density distribution via the electron-nuclear hyperfine interaction using EPR and ENDOR techniques. In this communication we report isotropic hyperfine coupling constants (hfcs) of the BChl b and g radical cations and anions, calculated by density functional theory, and compare them with the more common radical ions of BChl a and with available experimental data...
January 25, 2017: Photochemistry and Photobiology
Jennifer K Vanos, Grant R McKercher, Kylie Naughton, Marc Lochbaum
Childhood exposure to ultraviolet radiation (UVR) is a major risk factor for the development of melanoma later in life. However, it is challenging to accurately determine personal outdoor exposure to UVR, specifically erythemally weighted UVR (UVEry ), due to technological constraints, variable time-activity patterns, and the influence of outdoor environmental design. To address this challenge, this study utilized mobile and stationary techniques to examine the UVEry exposures of 14 children in a schoolyard in Lubbock, TX, in spring 2016...
January 18, 2017: Photochemistry and Photobiology
Maurício da Silva Baptista, Jean Cadet, Paolo Di Mascio, Ashwini A Ghogare, Alexander Greer, Michael R Hamblin, Carolina Lorente, Silvia Cristina Nunez, Martha Simões Ribeiro, Andrés H Thomas, Mariana Vignoni, Tania Mateus Yoshimura
Here, ten guidelines are presented for a standardized definition of type I and II photosensitized oxidation reactions. Because of varied notions of reactions mediated by photosensitizers, a checklist of recommendations is provided for their definitions. Type I and type II photoreactions are oxygen-dependent and involve unstable species such as the initial formation of radical cation or neutral radicals from the substrates and/or singlet oxygen ((1) O2(1) ∆g ) by energy transfer to molecular oxygen. In addition, superoxide anion radical (O2(•-) ) can be generated by a charge transfer reaction involving O2 or more likely indirectly as the result of O2 -mediated oxidation of the radical anion of type I photosensitizers...
January 13, 2017: Photochemistry and Photobiology
Stefan Rakete, Ram H Nagaraj
Whether ascorbate oxidation is promoted by UVA light in human lenses and whether this process is influenced by age and GSH levels are not known. In this study, we used paired lenses from human donors. One lens of each pair was exposed to UVA light, whereas the other lens was kept in the dark for the same period of time as the control. Using LC-MS/MS analyses, we found that older lenses (41-73 years) were more susceptible to UVA-induced ascorbate oxidation than younger lenses (18-40 years). Approximately 36% of the ascorbate (relative to control) was oxidized in older lenses compared to ~16% in younger lenses...
January 13, 2017: Photochemistry and Photobiology
Haixia Qiu, Michele M Kim, Rozhin Penjweini, Jarod C Finlay, Theresa M Busch, Tianhao Wang, Wensheng Guo, Keith A Cengel, Charles B Simone, Eli Glatstein, Timothy C Zhu
This preclinical study examines light fluence, photodynamic therapy (PDT) dose and "apparent reacted singlet oxygen," [(1) O2 ]rx , to predict local control rate (LCR) for Photofrin-mediated PDT of radiation-induced fibrosarcoma (RIF) tumors. Mice bearing RIF tumors were treated with in-air fluences (50-250 J cm(-2) ) and in-air fluence rates (50-150 mW cm(-2) ) at Photofrin dosages of 5 and 15 mg kg(-1) and a drug-light interval of 24 h using a 630-nm, 1-cm-diameter collimated laser. A macroscopic model was used to calculate [(1) O2 ]rx and PDT dose based on in vivo explicit dosimetry of the drug concentration, light fluence and tissue optical properties...
January 13, 2017: Photochemistry and Photobiology
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