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Editorial Board
Publication date: April 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 181
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Sunlight-induced genotoxicity and damage in keratin structures decrease tadpole performance
Publication date: April 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 181
Author(s): Caroline Peripolli dos Santos, James Eduardo Lago Londero, Maurício Beux dos Santos, Rayana dos Santos Feltrin, Luiza Loebens, Livia Bataioli Moura, Sonia Zanini Cechin, André Passaglia Schuch
The increased incidence of solar ultraviolet (UV) radiation, an environmental genotoxic agent, due to ozone depletion or deforestation may help to explain the enigmatic decline of amphibian populations in specific localities. In this work, we evaluated the importance of DNA repair performed by photolyases to maintain the performance of treefrog tadpoles after acute and chronic treatments with environmental-simulated doses of solar UVB and UVA radiation. Immediately after UV treatments, tadpoles were exposed to a visible light source to activate photolyases or kept in dark containers. The biological effects of UV treatments were evaluated through morphological, histological, locomotor and survival analyzes of Boana pulchella tadpoles (Anura: Hylidae). The results indicate that tadpole body weight suffered influence after both UVB and UVA treatments, although the body length was bit affected. The locomotor performance of UVB-exposed tadpoles was significantly reduced. In addition, UVB radiation induced a severe impact on tadpole skin, as well as on keratinized structures of mouth (tooth rows and jaw), indicating that these should be important effects of solar UV radiation in the reduction of tadpole performance. Furthermore, photolyases activation was fundamental for the maintenance of tadpole performance after chronic UVB exposures, but it was relatively inefficient after acute exposures to UVB, but not to UVA radiation. Therefore, this work demonstrates how the UV-induced genotoxicity and structural alterations in the skin and oral apparatus affect tadpole performance and survival.
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Human serum albumin binding to the biologically active labdane diterpene “leoheterin”: Spectroscopic and in silico analysis
Publication date: May 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 182
Author(s): Mohd. Sajid Ali, Musarat Amina, Hamad A. Al-Lohedan, Nawal M. Al Musayeib
Labdane diterpenes are important substances due to their remarkable biological activities such as, antibacterial, antiprotozoal, antifungal and cytostatic and cytotoxic effects against human cancer cells. We have isolated a labdane diterpene named “leoheterin” from the aerial parts of the Otostegia fruticosa Forssk (Briq) obtained from south west Arabian mountains of Saudi Arabia. The isolated compound was characterized by 1HNMR, 13CNMR, IR and UV–visible spectroscopies. Due to the pharmaceutical importance of this class of compounds we have studied the interaction of HSA with leoheterin by using several spectroscopic methods. The change in the UV spectrum of HSA in presence of leoheterin gives a primary idea about the interaction between them. Congruently, leoheterin quenches the fluorescence of HSA with a prominent blue shift of 5 nm, reminiscent of involvement of hydrophobic interactions. There was 1:1 binding between leoheterin and albumin which was taken place via static quenching mechanism. From CD it was revealed that leoheterin induces the secondary structure of HSA which is further supported by 3-d fluorescence measurements which shows a decrease in the size of the HSA-leoheterin complex as compared to the HSA alone. Molecular docking simulations presented that among the first three conformers, which have been arranged according to the least binding energies and are also in good corroboration with the free energies of binding obtained experimentally, the first two conformers shown the binding in hemin binding site of subdomain IB while in third conformer the binding site was near to the drug binding site 1 located in subdomain IIA. All conformers exhibited the involvement of hydrogen bonding as well as hydrophobic interactions.
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Swift fabrication of Ag nanostructures using a colloidal solution of Holostemma ada-kodien (Apocynaceae) – Antibiofilm potential, insecticidal activity against mosquitoes and non-target impact on water bugs
Publication date: April 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 181
Author(s): Sami A. Alyahya, Marimuthu Govindarajan, Naiyf S. Alharbi, Shine Kadaikunnan, Jamal M. Khaled, Ramzi A. Mothana, Mohammed N. Al-anbr, Baskaralingam Vaseeharan, Ramachandran Ishwarya, Mariappan Yazhiniprabha, Giovanni Benelli
Recent research in entomology and parasitology focused on the efficacy of green fabricated nanomaterials as novel insecticides. In this study, we synthesized poly-dispersed and stable silver nanoparticles (AgNPs) using the leaf extract of Holostemma ada-kodien. The nanostructures were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, and X-ray diffraction analysis. The efficacy of H. ada-kodien leaf extract and AgNPs in vector control was evaluated against the mosquitoes Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, which act as major vectors of important parasitic and arboviral diseases. AgNPs showed higher toxicity if compared to the H. ada-kodien leaf aqueous extract, LC50 towards larvae of A. stephensi, A. aegypti, and C. quinquefasciatus were 12.18, 13.30, and 14.70 μg/mL, respectively. When the AgNPs were tested on non-target water bugs, Diplonychus indicus, the LC50 value was 623.48 μg/mL. Furthermore, 100 μl/mL of AgNPs achieved significant antimicrobial activity against Bacillus pumilus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus vulgaris, and Candida albicans. Light and confocal laser scanning microscopy highlighted a major impact of the H. ada-kodien-synthesized AgNPs on the external topography and architecture of microbial biofilms, both on Gram-positive and Gram-negative bacteria. Overall, this study sheds light on the insecticidal and antibiofilm potential of H. ada-kodien-synthesized AgNPs, a potential green resource for the rapid synthesis of polydispersed and highly stable AgNPs.
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Synthesis of NiO nanoparticles via a green route using Monsonia burkeana: The physical and biological properties
Publication date: May 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 182
Author(s): P. Kganyago, L.M. Mahlaule-Glory, M.M. Mathipa, B. Ntsendwana, N. Mketo, Z. Mbita, N.C. Hintsho-Mbita
NiO nanoparticles have emerged as ideal candidates in various fields due to their magnetic, electrical and optical properties. The coupling of plant extracts that have anticancer and antibacterial properties with NiO nanoparticles has increased their usage in the biomedical field. In this work, we report on the novel synthesis of NiO nanoparticles using a local medicinal plant, Monsonia burkenea. The nickel nanoparticles were characterized using Fourier transform infrared spectroscopy (FTIR), Energy dispersive X-ray analysis (EDX), Scanning electron microscope (SEM), High-resolution transmission electron microscope (HRTEM) and X-ray diffraction (XRD). FTIR showed that the extraction of the plant phytochemicals was successful and the green synthesized nanoparticles from plants contained the phytochemical groups that are found in the Monsonia burkeana plant. XRD and HRTEM confirmed the successful formation of NiO nanoparticles with an average particle size range of 20 nm. These results were also corroborated by elemental mapping and EDX, where the dominant groups were identified.The Monsonia burkeana NiO particles exhibited selective bactericidal activity against Gram-negative strains, such as E. coli and P. aeruginosa. Additionally, cytotoxicity studies showed the materials did not have any anti proliferative effect against A549 lung cancer cells but could be used as potential drug delivery vehicles against human cancers.
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An improved green synthesis method and Escherichia coli antibacterial activity of silver nanoparticles
Publication date: Available online 7 April 2018
Source:Journal of Photochemistry and Photobiology B: Biology
Author(s): Pham Van Viet, Truong Tan Sang, Nguyen Ho Ngoc Bich, Cao Minh Thi
Silver nanoparticles (Ag NPs) were synthesized by an improved green synthesis method via a photo-reduction process using low-power UV light in the presence of poly (vinyl pyrrolidone) (PVP) as the surface stabilizer. The effective synthesis process was achieved by optimized synthesis parameters such as C2H5OH: H2O ratio, AgNO3: PVP ratio, pH value, and reducing time. The formation of Ag NPs was identified by Ultraviolet-visible (UV–vis) absorption spectra, X-ray diffraction pattern (XRD) and Fourier transform infrared spectroscopy (FTIR) spectra. Ag NPs were crystallized according to (111), (200), and (220) planes of the face-centered cubic. The transmission electron microscopy (TEM) image showed that the morphology of Ag NPs was uniform spherical with the average particle size of 16 ± 2 nm. The results of XRD pattern, TEM image, and dynamic light scattering (DLS) analysis proved that Ag crystals with uniform size were formed after the reduction process. The mechanism of the formation of Ag NPs was proposed and confirmed by FTIR spectra. The antibacterial activity of Ag NPs against Escherichia coli (E. coli) was tested and approximately 100% of E. coli was eliminated by Ag NPs 35 ppm. In the future, this study can become a new process for the application of Ag NPs as an antibiotic in the industrial scale.
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A novel stellerite-based photocatalytic composite and its enhanced disinfection application
Publication date: May 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 182
Author(s): Wanzhong Zhang, Haiyu Huang, Zhiming Sun, Shuilin Zheng, Caihong Yu
The aim of this work was to prepare, characterize and evaluate the potential of novel ZnO/stellerite composite photocatalysts against Staphylococcus aureus (S. aureus). SEM/EDS studies employed to study the surface morphological properties revealed stellerite as the catalysts carrier played a role of dispersant for ZnO nanoparticles. The XRD patterns of the ZnO/stellerite indicated hexagonal crystal structure with 20–30 nm size. It was found that the crystallite size of ZnO/stellerite was much smaller as compared to pure ZnO and increased with increasing ZnO loading amount. The results of optical properties of ZnO/stellerite showed smaller band gap in contrast to pure ZnO, investigated by UV–vis absorption. Due to the optimum ZnO loading, the as-prepared ZnO-20 composite had the highest BET surface area and the pore volume. Using the TG-DSC measurement, the high thermal stability of the product was studied for different temperature values. Antibacterial activity of ZnO/stellerite affected by the ZnO loading, concentration of samples and light conditions (under dark and UV irradiation conditions) was examined by disinfection of S. aureus. The as-prepared ZnO-20 composite with 100 mg/L was found to exhibit excellent inactivation efficiencies (87.65% in the dark and 97.67% under UV illumination) towards S. aureus. Compared with pure ZnO, the obtained composite photocatalysts showed significantly better antibacterial performance by studying the disinfection kinetics of S. aureus. Thus, the present study reveals that the novel ZnO/stellerite shows great potential for its use in the targeted disinfection applications.
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Effect of carbon limitation on photosynthetic electron transport in Nannochloropsis oculata
Publication date: April 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 181
Author(s): Tomáš Zavřel, Milán Szabó, Bojan Tamburic, Christian Evenhuis, Unnikrishnan Kuzhiumparambil, Petra Literáková, Anthony W.D. Larkum, John A. Raven, Jan Červený, Peter J. Ralph
This study describes the impacts of inorganic carbon limitation on the photosynthetic efficiency and operation of photosynthetic electron transport pathways in the biofuel-candidate microalga Nannochloropsis oculata. Using a combination of highly-controlled cultivation setup (photobioreactor), variable chlorophyll a fluorescence and transient spectroscopy methods (electrochromic shift (ECS) and P700 redox kinetics), we showed that net photosynthesis and effective quantum yield of Photosystem II (PSII) decreased in N. oculata under carbon limitation. This was accompanied by a transient increase in total proton motive force and energy-dependent non-photochemical quenching as well as slightly elevated respiration. On the other hand, under carbon limitation the rapid increase in proton motive force (PMF, estimated from the total ECS signal) was also accompanied by reduced conductivity of ATP synthase to protons (estimated from the rate of ECS decay in dark after actinic illumination). This indicates that the slow operation of ATP synthase results in the transient build-up of PMF, which leads to the activation of fast energy dissipation mechanisms such as energy-dependent non-photochemical quenching. N. oculata also increased content of lipids under carbon limitation, which compensated for reduced NAPDH consumption during decreased CO2 fixation. The integrated knowledge of the underlying energetic regulation of photosynthetic processes attained with a combination of biophysical methods may be used to identify photo-physiological signatures of the onset of carbon limitation in microalgal cultivation systems, as well as to potentially identify microalgal strains that can better acclimate to carbon limitation.
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Biologically synthesized titanium oxide nanostructures combined with morphogenetic protein as wound healing agent in the femoral fracture after surgery
Publication date: May 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 182
Author(s): Yushu Zhang, Chuanlian Zhang, Kemiao Liu, Xia Zhu, Fang Liu, Xiaofen Ge
The aim of the present study is to develop novel approach for the green synthesis of titanium oxide nanoparticles (TiO2 NPs) using Eichhornia crassipes extract and calcined at different temperatures for evaluate the wound healing activity in the femoral fracture. The synthesized TiO2 are formed different (plate and rod-like) nanostructures at various calcination temperatures. These samples were characterized by X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), Field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). Microscopic studies of TiO2 NPs revealed that the synthesized TiO2 NPs are formed well-defined rod-like structures at 400 °C with size ranged from 200 nm to 500 nm. The characterized plate and rod-like TiO2 NPs are combined with human morphogenetic protein (HbMP) to improving its wound healing activity and osteoblast properties on femoral fractures. The biocompatibility was tested by using human bone marrow mesenchymal stem cells (BMSC) cells and antibacterial efficacy analyzed using human pathogenica bacteria Staphylococcus aureus and Escherichia coli through agar well diffusion assay. The green synthesized rod-like TiO2 NPs combined with HbMP has been exhibited effective bone fusion behaviors with biomechanical properties and also improved antibacterial activity against pathogenic bacteria. From this study results, it is suggested that green synthesized TiO2NPs could be used effectively in biomedical application.
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Neuroprotective effect of Annona glabra extract against ethanol-induced apoptotic neurodegeneration in neonatal rats
Publication date: April 2018
Source:Journal of Photochemistry and Photobiology B: Biology, Volume 181
Author(s): Hongru Ma, Jianfeng Han, Qinchuan Dong
The present study aimed to investigate the neuroprotective effect of Annona glabra extract (AGE) against ethanol-induced neurodegeneration in neonatal rats. AGE is known to contain various pharmacological and therapeutic properties. Phytochemical analysis of AGE was performed to understand the presence of vital therapeutic components. Neonatal rats were assigned to the following groups: group I (normal control rats receiving normal saline), group II (control rats receiving ethanol), and group III (treated rats receiving ethanol-AGE). The lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (Gpx), superoxide dismutase (SOD), catalase, and acetylcholine esterase (AChE) levels were determined. Behavioral parameters, histological features, neuronal cell viability, and apoptosis were also investigated. The presence of flavonoids, terpenoid, glycosides, steroids, saponins, tannins, anthraquinones, and acidic compounds was noted in the AGE. Ethanol supplementation drastically increased the malondialdehyde (MDA) content to 52.17 nmol/g in the control rats (group II). However, the MDA content was reduced to 27.34 nmol/g in ethanol-AGE-treated neonatal rats (group III) compared with control rats. The GSH content was substantially reduced, to 33.68 mg/g, in control rats compared with in normal control rats. However, the GSH content was significantly increased, to 59.32 mg/g, following ethanol-AGE supplementation. Gpx, SOD, catalase, and AChE enzyme activities were increased in treated neonatal rats compared with their respective controls. Locomotor activities, such as crossing, grooming, rearing, and sniffing, were increased in ethanol-AGE-treated neonatal rats compared with controls. Reduced levels of intact pyramidal cells and cells with degenerative alterations appeared in the control rats. However, ethanol-AGE supplementation reduced degenerative alterations and hippocampal damage. Reduced cultured hippocampal neuron cell viability and increased apoptosis were noted in the control rats, whereas these impacts were significantly recovered following ethanol-AGE supplementation. Based on all these data, we concluded that the supplementation of AGE was very effective against ethanol-induced neurodegeneration in neonatal rats.
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