Cocoa ( L.) photobiological effect on human fibroblast cells (HFF-1) exposed to ultraviolet B (UVB) radiation.

This study aimed to investigate the photobiological action of cocoa solution on a human fibroblast cell line (HFF-1) exposed to ultraviolet B (UVB) radiation. Three experimental models were utilized, where fibroblast cells were treated with different concentrations of cocoa as follows: 50; 100; 250; 500; 750; 1000 or 1500 µg/ml and concomitantly exposed to UVB 7 kJ/m for 10 min. The following parameters were examined 1) analysis of the pre-treatment action of cocoa; 2) investigation of the co-treatment activity of cocoa at the time of exposure; and 3) study the effect of cocoa in the post-treatment of the damage initiated by UVB.

Light exposure of tetra-cationic porphyrins containing peripheral Pd(II)-bipyridyl complexes and the induced effects on purified DNA molecule, fibroblast and melanoma cell lines.

Photodynamic therapy (PDT) combines a light source, oxygen, and a photosensitizer (PS) to generate reactive oxygen species (ROS) for treating diseases. In this study, we evaluated two meso-tetra-pyridyl porphyrins with [Pd(bpy)Cl], namely 3-PdTPyP and 4-PdTPyP, as PS for PDT application. DNA interaction was assessed by spectroscopic measurements (UV-Vis and fluorescence emission), viscosity analysis, and molecular docking simulations.

Limited contribution of photoenzymatic DNA repair in mitigating carry-over effects from larval UVB exposure: Implications for frog recruitment.

Solar ultraviolet-B (UVB) radiation has increased due to stratospheric ozone depletion, climate and ecosystem changes and is a driver of amphibian population declines. Photoenzymatic repair (PER) is a critical mechanism for limiting UVB lethality in amphibian larvae. However, the link between PER and the UVB-induced effects remains understudied through long-term investigations in vivo.

DNA-Interactive and Damage Study with -Tetra(2-thienyl)porphyrins Coordinated with Polypyridyl Pd(II) and Pt(II) Complexes.

We report the DNA-binding properties of three porphyrins with peripheral thienyl substituents (, and ). The binding capacity of each porphyrin with DNA was determined by UV-Vis and steady-state fluorescence emission spectroscopy combined with molecular docking calculations. The results suggest that the interaction of these compounds probably occurs via secondary interactions via external grooves (minor grooves) around the DNA macromolecule.

Genotoxicity of surface waters in Brazil.

Brazil has abundant surface water resources, huge aquatic biodiversity and is home to 213 million people. Genotoxicity assays are sensitive tools to detect the effects of contaminants in surface waters and wastewaters, as well as to determine potential risks of contaminated waters to aquatic organisms and human health. This work aimed to survey the articles published in 2000-2021 that evaluated the genotoxicity of surface waters within Brazilian territory to unveil the profile and trends of this topic over time.

Effects of isolated and combined exposures of Boana curupi (Anura: Hylidae) tadpoles to environmental doses of trichlorfon and ultraviolet radiation.

The biodiversity collapse strongly affects the amphibian group and many factors have been pointed out as catalytic agents. It is estimated that several events in the amphibian population decline worldwide may have been caused by the interaction of multiple drivers. Thus, this study aimed to evaluate the stressful effects of the exposure to environmental doses of trichlorfon (TCF) pesticide (0.

Development of a rapid electrophoretic assay for genomic DNA damage quantification.

Accuracy, sensitivity, simplicity, reproducibility, and low-cost are desirable requirements for genotoxicity assessment techniques. Here we describe a simple electrophoretic assay for genomic DNA lesions quantification (EAsy-GeL) based on subjecting DNA samples to rapid unwinding/renaturation treatments and neutral agarose gel electrophoresis. The experiments performed in this work involved different biological samples exposed to increasing environmental-simulated doses of ultraviolet-B (UVB) radiation, such as Escherichia coli, human leukocytes, and isolated human genomic DNA.

UVB photoprotective capacity of hydrogels containing dihydromyricetin nanocapsules to UV-induced DNA damage.

We evaluate the effect of cationic nanocapsules containing dihydromyricetin (DMY) flavonoid for safe topical use in photoprotection against UV-induced DNA damage. The stability was investigated for feasibility to produce hydrogels containing cationic nanocapsules of the flavonoid DMY (NC-DMY) for 90 days under three different storage conditions (4 ± 2 °C, 25 ± 2 °C, and 40 ± 2 °C), as well as evaluation of skin permeation and its cytotoxicity in skin cell lines. The physicochemical and rheological characteristics were maintained during the analysis period under the different aforementioned conditions.

Open gaps in the evolution of the eukaryotic nucleotide excision repair.

Nucleotide excision repair (NER) is the most versatile DNA repair pathway as it removes different kinds of bulky lesions. Due to its essential role for genome integrity, it has appeared early in the evolution of species. However, most published studies are focused on humans, mice, yeast or bacteria.

DNA Damage Induced by Late Spring Sunlight in Antarctica.

Sunlight ultraviolet (UV) radiation constitutes an important environmental genotoxic agent that organisms are exposed to, as it can damage DNA directly, generating pyrimidine dimers, and indirectly, generating oxidized bases and single-strand breaks (SSBs). These lesions can lead to mutations, triggering skin and eye disorders, including carcinogenesis and photoaging. Stratospheric ozone layer depletion, particularly in the Antarctic continent, predicts an uncertain scenario of UV incidence on the Earth in the next decades.

DNA photocleavage and melanoma cells cytotoxicity induced by a meso-tetra-ruthenated porphyrin under visible light irradiation.

Porphyrins are used as photosensitizing agents in photodynamic therapy (PDT) for several pathologies. Here we demonstrate the DNA photocleavage and cytotoxicity properties of a free-base meso-tetra-ruthenated porphyrin (HRuTPyP) in purified DNA samples and in a melanoma cell line, respectively. Cytotoxicity of HRuTPyP was investigated by the tetrazolium dye (MTT) colorimetric assay and its genotoxic potential by direct plasmid DNA photocleavage after incubation with specific DNA repair enzymes.

Ecological light pollution affects anuran calling season, daily calling period, and sensitivity to light in natural Brazilian wetlands.

Ecological light pollution alters an environment's light cycle, potentially affecting photoperiod-controlled behavior. Anurans, for example, generally breed nocturnally, and the influence of light pollution on their natural history may therefore be especially strong. In this study, we tested this hypothesis by measuring male calling behavior of anuran communities in natural wetlands in southern Brazil exposed or not exposed to street lights.

Impact of solar UV radiation on amphibians: focus on genotoxic stress.

Solar UV radiation is one of the most important environmental genotoxic factors. Its incidence increased due to stratospheric ozone depletion, climate changes, and deforestation, and plays a crucial role in the worldwide decline of the populations of amphibians. Even sublethal effects of UV-induced genotoxicity may cause drastic consequences in the performance and fitness of amphibians.

Nanoencapsulation of the flavonoid dihydromyricetin protects against the genotoxicity and cytotoxicity induced by cationic nanocapsules.

We evaluated the influence of nanoencapsulation of the flavonoid Dihydromyricetin (DMY) in reducing the genotoxicity and cytotoxicity induced by cationic nanocapsules. Assays were conducted in order to evaluate the potential of protein corona formation, cytotoxicity, genotoxicity and the antioxidant capacity. Nanocapsules containing DMY (NC-DMY) and free DMY (DMY-F) did not demonstrate cytotoxicity and genotoxicity.

Genoprotective Effect of Phyllanthus orbicularis Extract Against UVA, UVB, and Solar Radiation.

One approach to protect the human skin against harmful effects of solar ultraviolet (UV) radiation was to use natural products as photoprotectors. In this work, the extract from specie Phyllanthus orbicularis K was evaluated as a protective agent against the photodamage by UVB, UVA artificial lamps, and environmental sunlight exposure. The plasmid DNA solutions were exposed to radiations using the DNA dosimeter system in the presence of plant extract.

Sunlight-induced genotoxicity and damage in keratin structures decrease tadpole performance.

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.

Direct participation of DNA in the formation of singlet oxygen and base damage under UVA irradiation.

UVA light is hardly absorbed by the DNA molecule, but recent works point to a direct mechanism of DNA lesion by these wavelengths. UVA light also excite endogenous chromophores, which causes DNA damage through ROS. In this study, DNA samples were irradiated with UVA light in different conditions to investigate possible mechanisms involved in the induction of DNA damage.

Sunlight damage to cellular DNA: Focus on oxidatively generated lesions.

The routine and often unavoidable exposure to solar ultraviolet (UV) radiation makes it one of the most significant environmental DNA-damaging agents to which humans are exposed. Sunlight, specifically UVB and UVA, triggers various types of DNA damage. Although sunlight, mainly UVB, is necessary for the production of vitamin D, which is necessary for human health, DNA damage may have several deleterious consequences, such as cell death, mutagenesis, photoaging and cancer.

An UV-sensitive anuran species as an indicator of environmental quality of the Southern Atlantic Rainforest.

The Southern Atlantic rainforest is continuously suffering from wood extraction activity, which results in the increase of clearings within the forest. Although the direct impacts of deforestation on landscape are already well described, there is an absence of studies focused on the evaluation of its indirect effects, such as the increase of solar UV radiation levels inside forest environment and its consequences for forest specialist anuran species. The results presented in this work clearly show that the threatened tree frog species Hypsiboas curupi presents severe traits of sensitivity to UV wavelengths of sunlight, making it a vulnerable species to this environmental stressor, as well as a biological indicator of the quality of forest canopy coverage.

Effects of heat and UV radiation on the mobilization of transposon mariner-Mos1.

There are many complex interactions between transposable elements (TEs) and host genomes. Environmental changes that induce stressful conditions help to contribute for increasing complexity of these interactions. The transposon mariner-Mos1 increases its mobilization under mild heat stress.

Highly sensitive biological assay for determining the photoprotective efficacy of sunscreen.

The protective effect of sunscreens has been extensively evaluated in vivo as a measure of erythema induced in human skin and is expressed as Sun Protection Factor (SPF). In vitro alternatives that use human cells might overcome the limitations of testing on human beings. Here is proposed a broad and accurate in vitro approach for evaluating the efficacy of commercial sunscreens even under environmental conditions.