scholarly journals Genotoxic Impact of Aluminum-containing Nanomaterials in Human Intestinal and Hepatic Cells.

2020 ◽  
Author(s):  
Pégah Jalili ◽  
Sylvie HUET ◽  
Agnès Burel ◽  
Benjamin-Christoph Krause ◽  
Caroline Fontana ◽  
...  

Abstract Background: Exposure of consumers to aluminum-containing nanomaterials (Al NMs) through numerous products is an area of concern for public health agencies since human health risks are not completely elucidated. In addition, the available data on the genotoxicity of Al2O3 and Al0 NMs are inconclusive or rare. In order to provide further information, the present study investigated the in vitro genotoxic potential of Al0 and Al2O3 NMs in intestinal and liver cell models since these tissues represent organs which would be in direct contact or could experience potential accumulation following oral exposure. Methods: Differentiated human intestinal Caco-2 and hepatic HepaRG cells were exposed to Al0 and Al2O3 NMs (0.03 to 80 µg/cm2) and the results were compared with those obtained with the ionic form AlCl3. Several methods, including H2AX labelling, the alkaline comet assay and micronucleus (MN) assays were used. Oxidative stress and oxidative DNA damage were assessed using High Content Analysis (HCA) and the formamidopyrimidine DNA-glycosylase -modified comet assay respectively. Moreover, carcinogenic properties of Al NMs were investigated through the cell transforming assay (CTA) in Bhas 42 cells.Results: The three forms of Al did not induce chromosomal damage when tested in the MN assay. Furthermore, no cell transformation was observed in Bhas 42 cells. However, although no production of oxidative stress was detected in HCA assays, Al2O3 NMs induced oxidative DNA damage in Caco-2 cells in the comet assay following a 24 h treatment. Considerable DNA damage was observed with Al0 NMs in both cell lines in the comet assay, although this was likely due to interference with these NMs. Finally, no genotoxic effects were observed with AlCl3. Conclusion: The slight effects observed with Al NMs are therefore not likely to be related to ion release in the cell media.

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4062
Author(s):  
Till Jasper Meyer ◽  
Agmal Scherzad ◽  
Helena Moratin ◽  
Thomas Eckert Gehrke ◽  
Julian Killisperger ◽  
...  

Radioresistance is an important cause of head and neck cancer therapy failure. Zinc oxide nanoparticles (ZnO-NP) mediate tumor-selective toxic effects. The aim of this study was to evaluate the potential for radiosensitization of ZnO-NP. The dose-dependent cytotoxicity of ZnO-NP20 nm and ZnO-NP100 nm was investigated in FaDu and primary fibroblasts (FB) by an MTT assay. The clonogenic survival assay was used to evaluate the effects of ZnO-NP alone and in combination with irradiation on FB and FaDu. A formamidopyrimidine-DNA glycosylase (FPG)-modified single-cell microgel electrophoresis (comet) assay was applied to detect oxidative DNA damage in FB as a function of ZnO-NP and irradiation exposure. A significantly increased cytotoxicity after FaDu exposure to ZnO-NP20 nm or ZnO-NP100 nm was observed in a concentration of 10 µg/mL or 1 µg/mL respectively in 30 µg/mL of ZnO-NP20 nm or 20 µg/mL of ZnO-NP100 nm in FB. The addition of 1, 5, or 10 µg/mL ZnO-NP20 nm or ZnO-NP100 nm significantly reduced the clonogenic survival of FaDu after irradiation. The sub-cytotoxic dosage of ZnO-NP100 nm increased the oxidative DNA damage compared to the irradiated control. This effect was not significant for ZnO-NP20 nm. ZnO-NP showed radiosensitizing properties in the sub-cytotoxic dosage. At least for the ZnO-NP100 nm, an increased level of oxidative stress is a possible mechanism of the radiosensitizing effect.


2019 ◽  
Vol 20 (S1) ◽  
Author(s):  
Camila F. A. Giordani ◽  
Sarah Campanharo ◽  
Nathalie R. Wingert ◽  
Lívia M. Bueno ◽  
Joanna W. Manoel ◽  
...  

Abstract Background The presence of impurities in some drugs may compromise the safety and efficacy of the patient’s treatment. Therefore, establishing of the biological safety of the impurities is essential. Diabetic patients are predisposed to tissue damage due to an increased oxidative stress process; and drug impurities may contribute to these toxic effects. In this context, the aim of this work was to study the toxicity, in 3 T3 cells, of the antidiabetic agents sitagliptin, vildagliptin, and their two main impurities of synthesis (S1 and S2; V1 and V2, respectively). Methods MTT reduction and neutral red uptake assays were performed in cytotoxicity tests. In addition, DNA damage (measured by comet assay), intracellular free radicals (by DCF), NO production, and mitochondrial membrane potential (ΔψM) were evaluated. Results Cytotoxicity was observed for impurity V2. Free radicals generation was found at 1000 μM of sitagliptin and 10 μM of both vildagliptin impurities (V1 and V2). A decrease in NO production was observed for all vildagliptin concentrations. No alterations were observed in ΔψM or DNA damage at the tested concentrations. Conclusions This study demonstrated that the presence of impurities might increase the cytotoxicity and oxidative stress of the pharmaceutical formulations at the concentrations studied.


2006 ◽  
Vol 74 (12) ◽  
pp. 6839-6846 ◽  
Author(s):  
Ge Wang ◽  
Yang Hong ◽  
Adriana Olczak ◽  
Susan E. Maier ◽  
Robert J. Maier

ABSTRACT Neutrophil-activating protein (NapA) has been well documented to play roles in human neutrophil recruitment and in stimulating host cell production of reactive oxygen intermediates (ROI). A separate role for NapA in combating oxidative stress within H. pylori was implied by studies of various H. pylori mutant strains. Here, physiological analysis of a napA strain was the approach used to assess the iron-sequestering and stress resistance roles of NapA, its role in preventing oxidative DNA damage, and its importance to mouse colonization. The napA strain was more sensitive to oxidative stress reagents and to oxygen, and it contained fourfold more intracellular free iron and more damaged DNA than the parent strain. Pure, iron-loaded NapA bound to DNA, but native NapA did not, presumably linking iron levels sensed by NapA to DNA damage protection. Despite its in vitro phenotype of sensitivity to oxidative stress, the napA strain showed normal (like that of the wild type) mouse colonization efficiency in the conventional in vivo assay. By use of a modified mouse inoculation protocol whereby nonviable H. pylori is first inoculated into mice, followed by (live) bacterial strain administration, an in vivo role for NapA in colonization efficiency could be demonstrated. NapA is the critical component responsible for inducing host-mediated ROI production, thus inhibiting colonization by the napA strain. An animal colonization experiment with a mixed-strain infection protocol further demonstrated that the napA strain has significantly decreased ability to survive when competing with the wild type. H. pylori NapA has unique and separate roles in gastric pathogenesis.


2000 ◽  
Vol 54 (1) ◽  
pp. 137-145 ◽  
Author(s):  
M. Takahashi ◽  
K. Keicho ◽  
H. Takahashi ◽  
H. Ogawa ◽  
R.M. Schulte ◽  
...  

2021 ◽  
pp. 096032712110361
Author(s):  
Marzieh Farahani-Zangaraki ◽  
Azade Taheri ◽  
Mahmoud Etebari

Introduction: Hyperinsulinemia occurs in type 2 diabetic patients with insulin resistance. This increase in insulin levels in the blood increases reactive oxygen species production and oxidative stress, resulting in DNA damage. Carvedilol (CRV) is a non-selective beta-blocker, and research has shown that this compound and its metabolites have anti-oxidative properties. Carvedilol can, directly and indirectly, reduce reactive oxygen species (ROS) and has a protective effect on DNA damage from oxidative stress. Given the insolubility of CRV in water, finding new methods to increase its solubility can be an essential step in research. This study aimed to determine whether carvedilol could have a protective effect on insulin-induced genomic damage. Methods: We treated cells with insulin alone, amorphous-CRV alone, and amorphous-CRV and niosomal-CRV with insulin and DNA damage were investigated using the comet method to achieve this goal. Results: Our results showed that insulin in the studied concentration has a significant genotoxic effect and non-cytotoxic at higher concentrations. CRV, both in amorphous and niosome form, reduced insulin-induced DNA damage by reducing ROS production. The comet assay results demonstrate that treating HUVEC cells in pretreatment condition with amorphous-CRV and niosome-CRV significantly reduces DNA damage of insulin.


2012 ◽  
Vol 48 (3) ◽  
pp. 193-202 ◽  
Author(s):  
Stefan Karger ◽  
Kerstin Krause ◽  
Cornelia Engelhardt ◽  
Carl Weidinger ◽  
Oliver Gimm ◽  
...  

Increased oxidative stress has been linked to thyroid carcinogenesis. In this paper, we investigate whether oxidative DNA damage and DNA repair differ in follicular adenoma (FA) and follicular thyroid carcinoma (FTC). 7,8-Dihydro-8-oxoguanine (8-OxoG) formation was analysed by immunohistochemistry in 46 FAs, 52 FTCs and 18 normal thyroid tissues (NTs). mRNA expression of DNA repair genes OGG1, Mut Y homologue (MUTYH) and endonuclease III (NTHL1) was analysed by real-time PCR in 19 FAs, 25 FTCs and 19 NTs. Induction and repair of oxidative DNA damage were studied in rat FRTL-5 cells after u.v. irradiation. Moreover, activation of DNA damage checkpoints (ataxia telangiectasia mutated (ATM) and H2A histone family, member X (H2AFX (H2AFX))) and proliferation index (MIB-1) were quantified in 28 non-oxyphilic and 24 oxyphilic FTCs. Increased nuclear and cytosolic 8-OxoG formation was detected in FTC compared with follicular adenoma, whereby cytosolic 8-OxoG formation was found to reflect RNA oxidation. Significant downregulation of DNA repair enzymes was detected in FTC compared with FA. In vitro experiments mirrored the findings in FTC with oxidative stress-induced DNA checkpoint activation and downregulation of OGG1, MUTYH and NTHL1 in FRTL-5 cells, an effect that, however, was reversible after 24 h. Further analysis of FTC variants showed decreased oxidative DNA damage, sustained checkpoint activation and decreased proliferation in oxyphilic vs non-oxyphilic FTC. Our data suggest a pathophysiological scenario of accumulating unrepaired DNA/RNA damage in FTC vs counterbalanced DNA/RNA damage and repair in FA. Furthermore, this study provides the first evidence for differences in oxidative stress defence in FTC variants with possible implications for therapeutic response and prognostic outcome.


2016 ◽  
Vol 38 (2) ◽  
pp. 150-162 ◽  
Author(s):  
Bhupesh Patel ◽  
Saroj Kumar Das ◽  
Manorama Patri

Humans are exposed to polycyclic aromatic hydrocarbons (PAHs) by ingestion of contaminated food and water. Prenatal exposure to benzo[a]pyrene (B[a]P) like PAHs through the placental barrier and neonatal exposure by breast milk and the environment may affect early brain development. In the present study, single intracisternal administration of B[a]P (0.2 and 2.0 µg/kg body weight) to male Wistar rat pups at postnatal day 5 (PND5) was carried out to study its specific effect on neonatal brain development and its consequences at PND30. B[a]P administration showed a significant increase in exploratory and anxiolytic-like behaviour with elevated hippocampal lipid peroxidation and protein oxidation at PND30. Further, DNA damage was estimated in vitro (Neuro2a and C6 cell lines) by the comet assay, and oxidative DNA damage of hippocampal sections was measured in vivo following exposure to B[a]P. DNA strand breaks (single and double) significantly increased due to B[a]P at PND30 in hippocampal neurons and increased the nuclear tail moment in Neuro2a cells. Hippocampal 8-oxo-2′-deoxyguanosine production was significantly elevated showing expression of more TUNEL-positive cells in both doses of B[a]P. Histological studies also revealed a significant reduction in mean area and perimeter of hippocampal neurons in rats treated with B[a]P 2.0 μg/kg, when compared to naïve and control rats. B[a]P significantly increased anxiolytic-like behaviour and oxidative DNA damage in the hippocampus causing apoptosis that may lead to neurodegeneration in adolescence. The findings of the present study address the potential role of B[a]P in inducing oxidative stress-mediated neurodegeneration in the hippocampus through oxidative DNA damage in the early adolescence period of rats.


Author(s):  
Delia Cavallo ◽  
Cinzia Lucia Ursini ◽  
Anna Maria Fresegna ◽  
Aureliano Ciervo ◽  
Raffaele Maiello ◽  
...  

This study aimed to identify sensitive and noninvasive biomarkers of early cyto-genotoxic, oxidative and inflammatory effects for exposure to volatile organic compounds (VOCs) in shipyard painters. On 17 (11 spray and 6 roller) painters (previously characterized for VOCs exposure to toluene, xylenes, ethylbenzene, ethyl acetate) and on 18 controls, we performed buccal micronucleus cytome (BMCyt) assay; Fpg-comet assay on lymphocytes; detection of urinary 8-oxoGua (8-oxo-7,8-dihydroguanine), 8-oxodGuo (8-oxo-7,8-dihydro-2′-deoxyguanosine) and 8-oxoGuo (8-oxo-7,8-dihydroguanosine), and cytokines release on serum. We found induction of cyto-genotoxicity by BMCyt assay and inflammatory effects (IL-6 and TNFα) in roller painters exposed to lower VOC concentrations than spray painters. In contrast, in both worker groups, we found direct and oxidative DNA damage by comet assay (with slightly higher oxidative DNA damage in roller) and significant increase of 8-oxoGuo and decrease of 8-oxodGuo and 8-oxoGua in respect to controls. The cyto-genotoxicity observed only on buccal cells of roller painters could be related to the task’s specificity and the different used protective equipment. Although limited by the small number of subjects, the study shows the usefulness of all the used biomarkers in the risk assessment of painters workers exposed to complex mixtures.


2011 ◽  
Vol 301 (1) ◽  
pp. E91-E98 ◽  
Author(s):  
Yi-Fen Lee ◽  
Su Liu ◽  
Ning-Chun Liu ◽  
Ruey-Sheng Wang ◽  
Lu-Min Chen ◽  
...  

Early studies suggest that TR4 nuclear receptor is a key transcriptional factor regulating various biological activities, including reproduction, cerebella development, and metabolism. Here we report that mice lacking TR4 ( TR4−/−) exhibited increasing genome instability and defective oxidative stress defense, which are associated with premature aging phenotypes. At the cellular level, we observed rapid cellular growth arrest and less resistance to oxidative stress and DNA damage in TR4−/− mouse embryonic fibroblasts (MEFs) in vitro. Restoring TR4 or supplying the antioxidant N-acetyl-l-cysteine (NAC) to TR4−/− MEFs reduced the DNA damage and slowed down cellular growth arrest. Focused qPCR array revealed alteration of gene profiles in the DNA damage response (DDR) and anti-reactive oxygen species (ROS) pathways in TR4−/− MEFs, which further supports the hypothesis that the premature aging in TR4−/− mice might stem from oxidative DNA damage caused by increased oxidative stress or compromised genome integrity. Together, our finding identifies a novel role of TR4 in mediating the interplay between oxidative stress defense and aging.


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