117 results on '"Žegura B"'
Search Results
2. P26-14: Assessment of tyrosine kinase inhibitors cytotoxic and genotoxic effects in non-target zebrafish liver (ZFL) cells in vitro
- Author
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Kološa, K., primary, Novak, M., additional, Štampar, M., additional, Žegura, B., additional, and Filipič, M., additional
- Published
- 2023
- Full Text
- View/download PDF
3. P03-10: Assessment of the (geno)toxic potential of Vanadium-doped iron-oxide nanozymes in vitro
- Author
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Štern, A., primary, Žabkar, S., additional, Rozman, I., additional, Sáenz Hernández, A., additional, Moreno-Maldonado, A.C., additional, Fuentes, J.A., additional, Goya, G.F., additional, and Žegura, B., additional
- Published
- 2023
- Full Text
- View/download PDF
4. P03-20: Adverse (geno)toxic effects of bisphenol A its two analogues BPAP and BPC and their complex mixtures in a 3D HepG2 cell model
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Štampar, M., primary, Ravnjak, T., additional, Sendra Vega, M., additional, Fras, K., additional, Domijan, A.-M., additional, and Žegura, B., additional
- Published
- 2023
- Full Text
- View/download PDF
5. Micronucleus Experiments with Fish Cell Lines
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Žegura, B., primary and Filipič, M., additional
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- 2019
- Full Text
- View/download PDF
6. Microcystin-LR induced DNA damage in human peripheral blood lymphocytes
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Žegura, B., Gajski, G., Štraser, A., Garaj-Vrhovac, V., and Filipič, M.
- Published
- 2011
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- View/download PDF
7. P10-09: Toxicological aspects of the Horizon EDIAQI project
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Lovrić, M., Zegura, B., Gerić, M., Vrhovac Madunić, I., Karaica, D., Micek, V., Milić, M., Turkalj, M., Banic, I., Switters, J., Mureddu, F., and Gajski, G.
- Published
- 2023
- Full Text
- View/download PDF
8. Cylindrospermopsin induced DNA damage and alteration in the expression of genes involved in the response to DNA damage, apoptosis and oxidative stress
- Author
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Žegura, B., Gajski, G., Štraser, A., and Garaj-Vrhovac, V.
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- 2011
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9. Both cerivastatin and fenofibrate improve arterial vasoreactivity in patients with combined hyperlipidaemia
- Author
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ŠEBEŠTJEN, M., ŽEGURA, B., and KEBER, I.
- Published
- 2002
10. Genotoxic potential of the binary mixture of cyanotoxins microcystin-LR and cylindrospermopsin
- Author
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Hercog, K., primary, Maisanaba, S., additional, Filipič, M., additional, Jos, A., additional, Cameán, A.M., additional, and Žegura, B., additional
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- 2016
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11. Protective effect of linalool, myrcene and eucalyptol against t-butyl hydroperoxide induced genotoxicity in bacteria and cultured human cells
- Author
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Mitić-Ćulafić, D., primary, Žegura, B., additional, Nikolić, B., additional, Vuković-Gačić, B., additional, Knežević-Vukčević, J., additional, and Filipič, M., additional
- Published
- 2009
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12. Toxicity and genotoxicity studies of surface and waste water samples using a bacterial SOS/umu test and mammalian MTT and comet assay
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Žegura, B., primary, Heath, E., additional, Černoša, A., additional, and Filipič, M., additional
- Published
- 2006
- Full Text
- View/download PDF
13. No difference in improvement of flow mediated dilation after oral or transdermal estradiol substitution after surgical induced menopause
- Author
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Žegura, B., primary, S̆ebeštjen, M., additional, Keber, I., additional, and Borko, E., additional
- Published
- 2000
- Full Text
- View/download PDF
14. Cerivastatin improves flow-mediated dilatation more than fenofibrate in males with mixed hyperlipidemia
- Author
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S̆ebeštjen, M., primary, Žegura, B., additional, and Keber, I., additional
- Published
- 2000
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15. Incidence of positive peritoneal cytology in patients with endometrial carcinoma after hysteroscopy vs. dilatation and curettage
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Dovnik Andraz, Crnobrnja Bojana, Zegura Branka, Takac Iztok, and Pakiz Maja
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endometrial carcinoma ,peritoneal cytology ,figo staging ,hysteroscopy ,dilatation and curettage ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
The aim of the study was to compare the frequency of positive peritoneal washings in endometrial cancer patients after either hysteroscopy (HSC) or dilatation and curettage (D&C).
- Published
- 2016
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16. VARIOUS HORMONAL REPLACEMENT THERAPIES AND RISK FACTORS FOR ATHEROSCLEROSIS
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Źegura, B., Guzic-Salobir, B., Sebestjen, M., and Keber, I.
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- 2009
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17. Mo-P1:135 Role of endothelial function and inflammation in patients with cardiovascular risk factors, with and without a history of myocardial infarction
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Sebestjen, M., Erzen, B., Zegura, B., Sabovic, M., Poredos, P., and Keber, I.
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- 2006
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18. Mo-P1:134 Determinants of endothelial dysfunction and carotid intima media thickness in combined hyperlipidemia
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Sebestjen, M., Zegura, B., Videenik, V., and Keber, I.
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- 2006
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19. P02-11 Enhancing genotoxicity assessment: advanced 3D cell models for chemical testing.
- Author
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Durmišević, I., Haverić, A., Štampar, M., Žabkar, S., Omanović, M. Hadžić, Pećar, T. Ćetković, Štern, A., Kološa, K., Novak, M., Fras, K., Haverić, S., and Žegura, B.
- Subjects
- *
CHEMICAL testing , *CHEMICAL models , *GENETIC toxicology - Published
- 2024
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20. P03-10: Assessment of the (geno)toxic potential of Vanadium-doped iron-oxide nanozymesin vitro.
- Author
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Štern, A., Žabkar, S., Rozman, I., Sáenz Hernández, A., Moreno-Maldonado, A.C., Fuentes, J.A., Goya, G.F., and Žegura, B.
- Subjects
- *
IRON oxides - Published
- 2023
- Full Text
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21. Impact of indoor air pollution on DNA damage and chromosome stability: a systematic review.
- Author
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Kazensky L, Matković K, Gerić M, Žegura B, Pehnec G, and Gajski G
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- Humans, Animals, Chromosomal Instability drug effects, Comet Assay, Particulate Matter toxicity, Particulate Matter analysis, Histones metabolism, Environmental Monitoring methods, Genomic Instability drug effects, Biological Monitoring methods, Air Pollution, Indoor adverse effects, Air Pollution, Indoor analysis, DNA Damage, Air Pollutants toxicity, Micronucleus Tests
- Abstract
Indoor air pollution is becoming a rising public health problem and is largely resulting from the burning of solid fuels and heating in households. Burning these fuels produces harmful compounds, such as particulate matter regarded as a major health risk, particularly affecting the onset and exacerbation of respiratory diseases. As exposure to polluted indoor air can cause DNA damage including DNA sd breaks as well as chromosomal damage, in this paper, we aim to provide an overview of the impact of indoor air pollution on DNA damage and genome stability by reviewing the scientific papers that have used the comet, micronucleus, and γ-H2AX assays. These methods are valuable tools in human biomonitoring and for studying the mechanisms of action of various pollutants, and are readily used for the assessment of primary DNA damage and genome instability induced by air pollutants by measuring different aspects of DNA and chromosomal damage. Based on our search, in selected studies (in vitro, animal models, and human biomonitoring), we found generally higher levels of DNA strand breaks and chromosomal damage due to indoor air pollutants compared to matched control or unexposed groups. In summary, our systematic review reveals the importance of the comet, micronucleus, and γ-H2AX assays as sensitive tools for the evaluation of DNA and genome damaging potential of different indoor air pollutants. Additionally, research in this particular direction is warranted since little is still known about the level of indoor air pollution in households or public buildings and its impact on genetic material. Future studies should focus on research investigating the possible impact of indoor air pollutants in complex mixtures on the genome and relate pollutants to possible health outcomes., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2024
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22. Influence of alkylthio and arylthio derivatives of tert-butylquinone on the induction of DNA damage in a human hepatocellular carcinoma cell line (HepG2).
- Author
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Djordjevic Aleksic J, Kolarević S, Jovanović Marić J, Kračun-Kolarević M, Žegura B, Štern A, Sladić D, Novaković I, and Vuković-Gačić B
- Subjects
- Humans, Hep G2 Cells, Liver Neoplasms, Cell Cycle drug effects, Cell Survival drug effects, Carcinoma, Hepatocellular, Histones, Benzoquinones toxicity, DNA Damage drug effects, Comet Assay
- Abstract
The aim of this study was to investigate the effects of tert-butylquinone (TBQ) and its alkylthio and arylthio derivatives on DNA in vitro, using acellular and cellular test systems. Direct interaction with DNA was studied using the plasmid pUC19. Cytotoxic (MTS assay) and genotoxic (comet assay and γH2AX focus assays) effects, and their influence on the cell cycle were studied in the HepG2 cell line. Our results show that TBQ and its derivatives did not directly interact with DNA. The strongest cytotoxic effect on the HepG2 cells was observed for the derivative 2-tert-butyl-5,6-(ethylenedithio)-1,4-benzoquinone (IC
50 64.68 and 55.64 μM at 24-h and 48-h treatment, respectively). The tested derivatives did not significantly influence the cell cycle distribution in the exposed cellular populations. However, all derivatives showed a genotoxic activity stronger than that of TBQ in the comet assay, with 2-tert-butyl-5,6-(ethylenedithio)-1,4-benzoquinone producing the strongest effect. The same derivative also induced DNA double-strand breaks in the γH2AX focus assay., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)- Published
- 2024
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23. Exploring the safety of cannabidiol (CBD): A comprehensive in vitro evaluation of the genotoxic and mutagenic potential of a CBD isolate and extract from Cannabis sativa L.
- Author
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Štern A, Novak M, Kološa K, Trontelj J, Žabkar S, Šentjurc T, Filipič M, and Žegura B
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- Humans, Hep G2 Cells, Cell Survival drug effects, Micronucleus Tests, Cannabidiol pharmacology, Cannabidiol toxicity, Cannabidiol isolation & purification, Cannabis chemistry, Plant Extracts pharmacology, Plant Extracts toxicity, Mutagens toxicity, DNA Damage drug effects, Mutagenicity Tests
- Abstract
Cannabidiol (CBD), a naturally occurring cyclic terpenoid found in Cannabis sativa L., is renowned for its diverse pharmacological benefits. Marketed as a remedy for various health issues, CBD products are utilized by patients as a supplementary therapy or post-treatment failure, as well as by healthy individuals seeking promised advantages. Despite its widespread use, information regarding potential adverse effects, especially genotoxic properties, is limited. The present study is focused on the mutagenic and genotoxic activity of a CBD isolate (99.4 % CBD content) and CBD-rich Cannabis sativa L extract (63.6 % CBD content) in vitro. Both CBD samples were non-mutagenic, as determined by the AMES test (OECD 471) but exhibited cytotoxicity for HepG2 cells (∼IC
50 (4 h) 26 µg/ml, ∼IC50 (24 h) 6-8 µg/ml, MTT assay). Noncytotoxic concentrations induced upregulation of genes encoding metabolic enzymes involved in CBD metabolism, and CBD oxidative as well as glucuronide metabolites were found in cell culture media, demonstrating the ability of HepG2 cells to metabolize CBD. In this study, the CBD samples were found non-genotoxic. No DNA damage was observed with the comet assay, and no influence on genomic instability was observed with the cytokinesis block micronucleus and the γH2AX and p-H3 assays. Furthermore, no changes in the expression of genes involved in genotoxic stress response were detected in the toxicogenomic analysis, after 4 and 24 h of exposure. Our comprehensive study contributes valuable insights into CBD's safety profile, paving the way for further exploration of CBD's therapeutic applications and potential adverse effects., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)- Published
- 2024
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24. Author Correction: Hazard characterization of Alternaria toxins to identify data gaps and improve risk assessment for human health.
- Author
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Louro H, Vettorazzi A, López de Cerain A, Spyropoulou A, Solhaug A, Straumfors A, Behr AC, Mertens B, Žegura B, Fæste CK, Ndiaye D, Spilioti E, Varga E, Dubreil E, Borsos E, Crudo F, Eriksen GS, Snapkow I, Henri J, Sanders J, Machera K, Gaté L, Le Hegarat L, Novak M, Smith NM, Krapf S, Hager S, Fessard V, Kohl Y, Silva MJ, Dirven H, Dietrich J, and Marko D
- Published
- 2024
- Full Text
- View/download PDF
25. Supplementation of vitamin E as an addition to a commercial renal diet does not prolong survival of cats with chronic kidney disease.
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Krofič Žel M, Tavčar Kalcher G, Vovk T, Žegura B, Lusa L, Tozon N, and Nemec Svete A
- Subjects
- Animals, Cats, Male, Female, Double-Blind Method, Oxidative Stress drug effects, Malondialdehyde blood, DNA Damage drug effects, Animal Feed analysis, Diet veterinary, Protein Carbonylation drug effects, Vitamin E administration & dosage, Vitamin E therapeutic use, Renal Insufficiency, Chronic veterinary, Renal Insufficiency, Chronic diet therapy, Renal Insufficiency, Chronic drug therapy, Cat Diseases drug therapy, Cat Diseases diet therapy, Dietary Supplements
- Abstract
Background: The aim of this double-blind, placebo-controlled study was to investigate the effect of vitamin E supplementation as an addition to a commercial renal diet on survival time of cats with different stages of chronic kidney disease (CKD). In addition, we were interested whether vitamin E supplementation affects selected oxidative stress and clinical parameters. Thirty-four cats with CKD and 38 healthy cats were included in the study. Cats with CKD were classified according to the IRIS Guidelines; seven in IRIS stage 1, 15 in IRIS stage 2, five in IRIS stage 3 and seven in IRIS stage 4. Cats with CKD were treated according to IRIS Guidelines. Cats with CKD were randomly assigned to receive vitamin E (100 IU/cat/day) or placebo (mineral oil) for 24 weeks in addition to standard therapy. Plasma malondialdehyde (MDA) and protein carbonyl (PC) concentrations, DNA damage of peripheral lymphocytes and plasma vitamin E concentrations were measured at baseline and four, eight, 16 and 24 weeks thereafter. Routine laboratory analyses and assessment of clinical signs were performed at each visit., Results: Vitamin E supplementation had no effect on the survival time and did not reduce the severity of clinical signs. Before vitamin E supplementation, no significant differences in vitamin E, MDA and PC concentrations were found between healthy and CKD cats. However, plasma MDA concentration was statistically significantly higher (p = 0.043) in cats with early CKD (IRIS stages 1 and 2) than in cats with advanced CKD (IRIS stages 3 and 4). Additionally, DNA damage was statistically significantly higher in healthy cats (p ≤ 0.001) than in CKD cats. Plasma vitamin E concentrations increased statistically significantly in the vitamin E group compared to the placebo group four (p = 0.013) and eight (p = 0.017) weeks after the start of vitamin E supplementation. During the study and after 24 weeks of vitamin E supplementation, plasma MDA and PC concentrations and DNA damage remained similar to pre-supplementation levels in both the placebo and vitamin E groups., Conclusions: Vitamin E supplementation as an addition to standard therapy does not prolong survival in feline CKD., (© 2024. The Author(s).)
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- 2024
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26. Exploring BPA alternatives - Environmental levels and toxicity review.
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Adamovsky O, Groh KJ, Białk-Bielińska A, Escher BI, Beaudouin R, Mora Lagares L, Tollefsen KE, Fenske M, Mulkiewicz E, Creusot N, Sosnowska A, Loureiro S, Beyer J, Repetto G, Štern A, Lopes I, Monteiro M, Zikova-Kloas A, Eleršek T, Vračko M, Zdybel S, Puzyn T, Koczur W, Ebsen Morthorst J, Holbech H, Carlsson G, Örn S, Herrero Ó, Siddique A, Liess M, Braun G, Srebny V, Žegura B, Hinfray N, Brion F, Knapen D, Vandeputte E, Stinckens E, Vergauwen L, Behrendt L, João Silva M, Blaha L, and Kyriakopoulou K
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- Animals, Humans, Endocrine Disruptors toxicity, Phenols toxicity, Benzhydryl Compounds toxicity, Environmental Pollutants toxicity, Environmental Monitoring methods
- Abstract
Bisphenol A alternatives are manufactured as potentially less harmful substitutes of bisphenol A (BPA) that offer similar functionality. These alternatives are already in the market, entering the environment and thus raising ecological concerns. However, it can be expected that levels of BPA alternatives will dominate in the future, they are limited information on their environmental safety. The EU PARC project highlights BPA alternatives as priority chemicals and consolidates information on BPA alternatives, with a focus on environmental relevance and on the identification of the research gaps. The review highlighted aspects and future perspectives. In brief, an extension of environmental monitoring is crucial, extending it to cover BPA alternatives to track their levels and facilitate the timely implementation of mitigation measures. The biological activity has been studied for BPA alternatives, but in a non-systematic way and prioritized a limited number of chemicals. For several BPA alternatives, the data has already provided substantial evidence regarding their potential harm to the environment. We stress the importance of conducting more comprehensive assessments that go beyond the traditional reproductive studies and focus on overlooked relevant endpoints. Future research should also consider mixture effects, realistic environmental concentrations, and the long-term consequences on biota and ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2024
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27. Nature-inspired substituted 3-(imidazol-2-yl) morpholines targeting human topoisomerase IIα: Dynophore-derived discovery.
- Author
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Herlah B, Janežič M, Ogris I, Grdadolnik SG, Kološa K, Žabkar S, Žegura B, and Perdih A
- Subjects
- Humans, Cell Line, Tumor, Drug Discovery methods, Antineoplastic Agents pharmacology, Antineoplastic Agents chemistry, Molecular Docking Simulation, Structure-Activity Relationship, Imidazoles pharmacology, Imidazoles chemistry, DNA Breaks, Double-Stranded drug effects, Antigens, Neoplasm metabolism, DNA Topoisomerases, Type II metabolism, Topoisomerase II Inhibitors pharmacology, Topoisomerase II Inhibitors chemistry
- Abstract
The molecular nanomachine, human DNA topoisomerase IIα, plays a crucial role in replication, transcription, and recombination by catalyzing topological changes in the DNA, rendering it an optimal target for cancer chemotherapy. Current clinical topoisomerase II poisons often cause secondary tumors as side effects due to the accumulation of double-strand breaks in the DNA, spurring the development of catalytic inhibitors. Here, we used a dynamic pharmacophore approach to develop catalytic inhibitors targeting the ATP binding site of human DNA topoisomerase IIα. Our screening of a library of nature-inspired compounds led to the discovery of a class of 3-(imidazol-2-yl) morpholines as potent catalytic inhibitors that bind to the ATPase domain. Further experimental and computational studies identified hit compound 17, which exhibited selectivity against the human DNA topoisomerase IIα versus human protein kinases, cytotoxicity against several human cancer cells, and did not induce DNA double-strand breaks, making it distinct from clinical topoisomerase II poisons. This study integrates an innovative natural product-inspired chemistry and successful implementation of a molecular design strategy that incorporates a dynamic component of ligand-target molecular recognition, with comprehensive experimental characterization leading to hit compounds with potential impact on the development of more efficient chemotherapies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
28. Hazard characterization of Alternaria toxins to identify data gaps and improve risk assessment for human health.
- Author
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Louro H, Vettorazzi A, López de Cerain A, Spyropoulou A, Solhaug A, Straumfors A, Behr AC, Mertens B, Žegura B, Fæste CK, Ndiaye D, Spilioti E, Varga E, Dubreil E, Borsos E, Crudo F, Eriksen GS, Snapkow I, Henri J, Sanders J, Machera K, Gaté L, Le Hegarat L, Novak M, Smith NM, Krapf S, Hager S, Fessard V, Kohl Y, Silva MJ, Dirven H, Dietrich J, and Marko D
- Subjects
- Humans, Alternaria metabolism, Mutagens toxicity, Mutagens metabolism, Lactones toxicity, Lactones metabolism, Risk Assessment, Food Contamination analysis, Perylene, Mycotoxins toxicity, Mycotoxins analysis
- Abstract
Fungi of the genus Alternaria are ubiquitous plant pathogens and saprophytes which are able to grow under varying temperature and moisture conditions as well as on a large range of substrates. A spectrum of structurally diverse secondary metabolites with toxic potential has been identified, but occurrence and relative proportion of the different metabolites in complex mixtures depend on strain, substrate, and growth conditions. This review compiles the available knowledge on hazard identification and characterization of Alternaria toxins. Alternariol (AOH), its monomethylether AME and the perylene quinones altertoxin I (ATX-I), ATX-II, ATX-III, alterperylenol (ALP), and stemphyltoxin III (STTX-III) showed in vitro genotoxic and mutagenic properties. Of all identified Alternaria toxins, the epoxide-bearing analogs ATX-II, ATX-III, and STTX-III show the highest cytotoxic, genotoxic, and mutagenic potential in vitro. Under hormone-sensitive conditions, AOH and AME act as moderate xenoestrogens, but in silico modeling predicts further Alternaria toxins as potential estrogenic factors. Recent studies indicate also an immunosuppressive role of AOH and ATX-II; however, no data are available for the majority of Alternaria toxins. Overall, hazard characterization of Alternaria toxins focused, so far, primarily on the commercially available dibenzo-α-pyrones AOH and AME and tenuazonic acid (TeA). Limited data sets are available for altersetin (ALS), altenuene (ALT), and tentoxin (TEN). The occurrence and toxicological relevance of perylene quinone-based Alternaria toxins still remain to be fully elucidated. We identified data gaps on hazard identification and characterization crucial to improve risk assessment of Alternaria mycotoxins for consumers and occupationally exposed workers., (© 2023. The Author(s).)
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- 2024
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29. Cold plasma within a stable supercavitation bubble - A breakthrough technology for efficient inactivation of viruses in water.
- Author
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Filipić A, Dobnik D, Gutiérrez-Aguirre I, Ravnikar M, Košir T, Baebler Š, Štern A, Žegura B, Petkovšek M, Dular M, Mozetič M, Zaplotnik R, and Primc G
- Subjects
- Animals, Humans, Water, Virus Inactivation, Plasma Gases pharmacology, Viruses
- Abstract
Water scarcity, one of the most pressing challenges we face today, has developed for many reasons, including the increasing number of waterborne pollutants that affect the safety of the water environment. Waterborne human, animal and plant viruses represent huge health, environmental, and financial burden and thus it is important to efficiently inactivate them. Therefore, the main objective of this study was to construct a unique device combining plasma with supercavitation and to evaluate its efficiency for water decontamination with the emphasis on inactivation of viruses. High inactivation (>5 log
10 PFU/mL) of bacteriophage MS2, a human enteric virus surrogate, was achieved after treatment of 0.43 L of recirculating water for up to 4 min. The key factors in the inactivation were short-lived reactive plasma species that damaged viral RNA. Water treated with plasma for a short time required for successful virus inactivation did not cause cytotoxic effects in the in vitro HepG2 cell model system or adverse effects on potato plant physiology. Therefore, the combined plasma-supercavitation device represents an environmentally-friendly technology that could provide contamination-free and safe water., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
30. Corrigendum to "Degradation and toxicity of bisphenol A and S during cold atmospheric pressure plasma treatment" J. Hazard. Mater. 454(2023) Article no. 131478.
- Author
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Kovačič A, Modic M, Hojnik N, Štampar M, Gulin MR, Nannou C, Koronaiou LA, Heath D, Walsh JL, Žegura B, Lambropoulou D, Cvelbar U, and Heath E
- Published
- 2023
- Full Text
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31. Degradation and toxicity of bisphenol A and S during cold atmospheric pressure plasma treatment.
- Author
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Kovačič A, Modic M, Hojnik N, Štampar M, Gulin MR, Nannou C, Koronaiou LA, Heath D, Walsh JL, Žegura B, Lambropoulou D, Cvelbar U, and Heath E
- Subjects
- Phenols toxicity, Phenols metabolism, Hydrogen Peroxide, Benzhydryl Compounds toxicity, Benzhydryl Compounds metabolism
- Abstract
Bisphenols are widely recognised as toxic compounds that potentially threaten the environment and public health. Here we report the use of cold atmospheric pressure plasma (CAP) to remove bisphenol A (BPA) and bisphenol S (BPS) from aqueous systems. Additionally, methanol was added as a radical scavenger to simulate environmental conditions. After 480 s of plasma treatment, 15-25 % of BPA remained, compared to > 80 % of BPS, with BPA being removed faster (-k
t = 3.4 ms-1 , half-life = 210 s) than BPS (-kt = 0.15 ms-1 , half-life 4700 s). The characterisation of plasma species showed that adding a radical scavenger affects the formation of reactive oxygen and nitrogen species, resulting in a lower amount of ˙OH, H2 O2 , and NO2 - but a similar amount of NO3 - . In addition, a non-target approach enabled the elucidation of 11 BPA and five BPS transformation products. From this data, transformation pathways were proposed for both compounds, indicating nitrification with further cleavage, demethylation, and carboxylation, and the coupling of smaller bisphenol intermediates. The toxicological characterisation of the in vitro HepG2 cell model has shown that the mixture of transformation products formed during CAP is less toxic than BPA and BPS, indicating that CAP is effective in safely degrading bisphenols., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)- Published
- 2023
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32. Cytotoxicity and Antibacterial Efficacy of Betaine- and Choline-Substituted Polymers.
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Jurko L, Makuc D, Štern A, Plavec J, Žegura B, Bošković P, and Kargl R
- Abstract
Cationic charge has been widely used to increase polymer adsorption and flocculation of dispersions or to provide antimicrobial activity. In this work, cationization of hydroxyethyl cellulose (HEC) and polyvinyl alcohol (PVA) was achieved by covalently coupling betaine hydrochloride and choline chloride to the polymer backbones through carbonyl diimidazole (CDI) activation. Two approaches for activation were investigated. CDI in excess was used to activate the polymers' hydroxyls followed by carbonate formation with choline chloride, or CDI was used to activate betaine hydrochloride, followed by ester formation with the polymers' hydroxyls. The first approach led to a more significant cross-linking of PVA, but not of HEC, and the second approach successfully formed ester bonds. Cationic, nitrogen-bearing materials with varying degrees of substitution were obtained in moderate to high yields. These materials were analyzed by Fourier transform infrared spectroscopy, nuclear magnetic resonance, polyelectrolyte titration, and kaolin flocculation. Their dose-dependent effect on the growth of Staphylococcus aureus and Pseudomonas aeruginosa , and L929 mouse fibroblasts, was investigated. Significant differences were found between the choline- and betaine-containing polymers, and especially, the choline carbonate esters of HEC strongly inhibited the growth of S. aureus in vitro but were also cytotoxic to fibroblasts. Fibroblast cytotoxicity was also observed for betaine esters of PVA but not for those of HEC. The materials could potentially be used as antimicrobial agents for instance by coating surfaces, but more investigations into the interaction between cells and polysaccharides are necessary to clarify why and how bacterial and human cells are inhibited or killed by these derivatives, especially those containing choline., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)
- Published
- 2023
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33. Combined Toxic Effects of BPA and Its Two Analogues BPAP and BPC in a 3D HepG2 Cell Model.
- Author
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Štampar M, Ravnjak T, Domijan AM, and Žegura B
- Subjects
- Humans, Hep G2 Cells, Oxidative Stress, Benzhydryl Compounds toxicity, Benzhydryl Compounds chemistry, Phenols toxicity, Phenols chemistry
- Abstract
Bisphenol A (BPA) is one of the most commonly used substances in the manufacture of various everyday products. Growing concerns about its hazardous properties, including endocrine disruption and genotoxicity, have led to its gradual replacement by presumably safer analogues in manufacturing plastics. The widespread use of BPA and, more recently, its analogues has increased their residues in the environment. However, our knowledge of their toxicological profiles is limited and their combined effects are unknown. In the present study, we investigated the toxic effects caused by single bisphenols and by the combined exposure of BPA and its two analogues, BPAP and BPC, after short (24-h) and prolonged (96-h) exposure in HepG2 spheroids. The results showed that BPA did not reduce cell viability in HepG2 spheroids after 24-h exposure. In contrast, BPAP and BPC affected cell viability in HepG2 spheroids. Both binary mixtures (BPA/BPAP and BPA/BPC) decreased cell viability in a dose-dependent manner, but the significant difference was only observed for the combination of BPA/BPC (both at 40 µM). After 96-h exposure, none of the BPs studied affected cell viability in HepG2 spheroids. Only the combination of BPA/BPAP decreased cell viability in a dose-dependent manner that was significant for the combination of 4 µM BPA and 4 µM BPAP. None of the BPs and their binary mixtures studied affected the surface area and growth of spheroids as measured by planimetry. In addition, all BPs and their binary mixtures studied triggered oxidative stress, as measured by the production of reactive oxygen species and malondialdehyde, at both exposure times. Overall, the results suggest that it is important to study the effects of BPs as single compounds. It is even more important to study the effects of combined exposures, as the combined effects may differ from those induced by single compounds.
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- 2023
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34. Measuring DNA modifications with the comet assay: a compendium of protocols.
- Author
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Collins A, Møller P, Gajski G, Vodenková S, Abdulwahed A, Anderson D, Bankoglu EE, Bonassi S, Boutet-Robinet E, Brunborg G, Chao C, Cooke MS, Costa C, Costa S, Dhawan A, de Lapuente J, Bo' CD, Dubus J, Dusinska M, Duthie SJ, Yamani NE, Engelward B, Gaivão I, Giovannelli L, Godschalk R, Guilherme S, Gutzkow KB, Habas K, Hernández A, Herrero O, Isidori M, Jha AN, Knasmüller S, Kooter IM, Koppen G, Kruszewski M, Ladeira C, Laffon B, Larramendy M, Hégarat LL, Lewies A, Lewinska A, Liwszyc GE, de Cerain AL, Manjanatha M, Marcos R, Milić M, de Andrade VM, Moretti M, Muruzabal D, Novak M, Oliveira R, Olsen AK, Owiti N, Pacheco M, Pandey AK, Pfuhler S, Pourrut B, Reisinger K, Rojas E, Rundén-Pran E, Sanz-Serrano J, Shaposhnikov S, Sipinen V, Smeets K, Stopper H, Teixeira JP, Valdiglesias V, Valverde M, van Acker F, van Schooten FJ, Vasquez M, Wentzel JF, Wnuk M, Wouters A, Žegura B, Zikmund T, Langie SAS, and Azqueta A
- Subjects
- Animals, Humans, Comet Assay methods, Eukaryotic Cells, DNA genetics, DNA Damage, Pyrimidine Dimers
- Abstract
The comet assay is a versatile method to detect nuclear DNA damage in individual eukaryotic cells, from yeast to human. The types of damage detected encompass DNA strand breaks and alkali-labile sites (e.g., apurinic/apyrimidinic sites), alkylated and oxidized nucleobases, DNA-DNA crosslinks, UV-induced cyclobutane pyrimidine dimers and some chemically induced DNA adducts. Depending on the specimen type, there are important modifications to the comet assay protocol to avoid the formation of additional DNA damage during the processing of samples and to ensure sufficient sensitivity to detect differences in damage levels between sample groups. Various applications of the comet assay have been validated by research groups in academia, industry and regulatory agencies, and its strengths are highlighted by the adoption of the comet assay as an in vivo test for genotoxicity in animal organs by the Organisation for Economic Co-operation and Development. The present document includes a series of consensus protocols that describe the application of the comet assay to a wide variety of cell types, species and types of DNA damage, thereby demonstrating its versatility., (© 2023. Springer Nature Limited.)
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- 2023
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35. Impact of Deoxynivalenol and Zearalenone as Single and Combined Treatment on DNA, Cell Cycle and Cell Proliferation in HepG2 Cells.
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Domijan AM, Hercog K, Štampar M, Gajski G, Gerić M, Sokolović M, and Žegura B
- Subjects
- Humans, Hep G2 Cells, Cell Cycle, Cell Proliferation, DNA pharmacology, Zearalenone toxicity, Mycotoxins pharmacology
- Abstract
The study aimed to investigate toxicity and the mechanism of toxicity of two Fusarium mycotoxins, deoxynivalenol (DON) and zearalenone (ZEA). DON and ZEA were applied to HepG2 cells as single compounds and in combination at low environmentally relevant concentrations. HepG2 cells were exposed to DON (0.5, 1, and 2 µM), ZEA (5, 10, and 20 µM) or their combinations (1 µM DON + 5 µM ZEA, 1 µM DON + 10 µM ZEA and 1 µM DON + 20 µM ZEA) for 24 h and cell viability, DNA damage, cell cycle and proliferation were assessed. Both mycotoxins reduced cell viability, however, combined treatment with DON and ZEA resulted in higher reduction of cell viability. DON (1 µM) induced primary DNA damage, while DON (1 µM) in combination with higher ZEA concentrations showed antagonistic effects compared to DON alone at 1 µM. DON arrested HepG2 cells in G2 phase and significantly inhibited cell proliferation, while ZEA had no significant effect on cell cycle. The combined treatment with DON and ZEA arrested cells in G2 phase to a higher extend compared to treatment with single mycotoxins. Potentiating effect observed after DON and ZEA co-exposure at environmentally relevant concentrations indicates that in risk assessment and setting governments' regulations, mixtures of mycotoxins should be considered.
- Published
- 2023
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36. Adverse Toxic Effects of Tyrosine Kinase Inhibitors on Non-Target Zebrafish Liver (ZFL) Cells.
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Kološa K, Žegura B, Štampar M, Filipič M, and Novak M
- Subjects
- Animals, Humans, Liver, Pyrimidines toxicity, Sorafenib toxicity, Zebrafish, Antineoplastic Agents toxicity, Hepatocytes drug effects, Tyrosine Kinase Inhibitors toxicity
- Abstract
Over the past 20 years, numerous tyrosine kinase inhibitors (TKIs) have been introduced for targeted therapy of various types of malignancies. Due to frequent and increasing use, leading to eventual excretion with body fluids, their residues have been found in hospital and household wastewaters as well as surface water. However, the effects of TKI residues in the environment on aquatic organisms are poorly described. In the present study, we investigated the cytotoxic and genotoxic effects of five selected TKIs, namely erlotinib (ERL), dasatinib (DAS), nilotinib (NIL), regorafenib (REG), and sorafenib (SOR), using the in vitro zebrafish liver cell (ZFL) model. Cytotoxicity was determined using the MTS assay and propidium iodide (PI) live/dead staining by flow cytometry. DAS, SOR, and REG decreased ZFL cell viability dose- and time-dependently, with DAS being the most cytotoxic TKI studied. ERL and NIL did not affect viability at concentrations up to their maximum solubility; however, NIL was the only TKI that significantly decreased the proportion of PI negative cells as determined by the flow cytometry. Cell cycle progression analyses showed that DAS, ERL, REG, and SOR caused the cell cycle arrest of ZFL cells in the G0/G1 phase, with a concomitant decrease of cells in the S-phase fraction. No data could be obtained for NIL due to severe DNA fragmentation. The genotoxic activity of the investigated TKIs was evaluated using comet and cytokinesis block micronucleus (CBMN) assays. The dose-dependent induction of DNA single strand breaks was induced by NIL (≥2 μM), DAS (≥0.006 μM), and REG (≥0.8 μM), with DAS being the most potent. None of the TKIs studied induced micronuclei formation. These results suggest that normal non-target fish liver cells are sensitive to the TKIs studied in a concentration range similar to those previously reported for human cancer cell lines. Although the TKI concentrations that induced adverse effects in exposed ZFL cells are several orders of magnitude higher than those currently expected in the aquatic environment, the observed DNA damage and cell cycle effects suggest that residues of TKIs in the environment may pose a hazard to non-intentionally exposed organisms living in environments contaminated with TKIs.
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- 2023
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37. In situ detection of the genotoxic potential as one of the lines of evidence in the weight-of-evidence approach-the Joint Danube Survey 4 Case Study.
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Jovanović Marić J, Kolarević S, Đorđević J, Sunjog K, Nikolić I, Marić A, Ilić M, Simonović P, Alygizakis N, Ng K, Oswald P, Slobodnik J, Žegura B, Vuković-Gačić B, Paunović M, and Kračun-Kolarević M
- Subjects
- Animals, Environmental Monitoring methods, Serbia, Micronucleus Tests, DNA Damage, Water Pollutants, Chemical toxicity, Water Pollutants, Chemical analysis
- Abstract
Environmental studies which aim to assess the ecological impact of chemical and other types of pollution should employ a complex weight-of-evidence approach with multiple lines of evidence (LoEs). This study focused on in situ genotoxicological methods such as the comet and micronucleus assays and randomly amplified polymorphic DNA analysis as one of the multiple LoEs (LoE3) on the fish species Alburnus alburnus (bleak) as a bioindicator. The study was carried out within the Joint Danube Survey 4 (JDS4) at nine sites in the Danube River Basin in the Republic of Serbia. Out of nine sampling sites, two were situated at the Tisa, Sava, and Velika Morava rivers, and three sites were at the Danube River. The three additionally employed LoEs were: SumTUwater calculated based on the monitoring data in the database of the Serbian Environmental Protection Agency (SEPA) (LoE1); in vitro analyses of JDS4 water extracts employing genotoxicological methods (LoE2); assessment of the ecological status/potential by SEPA and indication of the ecological status for the sites performed within the JDS4 (LoE4). The analyzed biomarker responses in the bleak were integrated into the unique integrated biomarker response index which was used to rank the sites. The highest pollution pressure was recorded at JDS4 39 and JDS4 36, while the lowest was at JDS4 35. The impact of pollution was confirmed at three sites, JDS4 33, 40, and 41, by all four LoEs. At other sampling sites, a difference was observed regarding the pollution depending on the employed LoEs. This indicates the importance of implementing a comprehensive weight-of-evidence approach to ensure the impact of pollution is not overlooked when using only one LoE as is often the case in environmental studies., (© The Author(s) 2022. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2023
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38. Adverse (geno)toxic effects of bisphenol A and its analogues in hepatic 3D cell model.
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Sendra M, Štampar M, Fras K, Novoa B, Figueras A, and Žegura B
- Subjects
- Humans, Hep G2 Cells, DNA, Benzhydryl Compounds toxicity, Benzhydryl Compounds chemistry, Phenols toxicity, Phenols chemistry
- Abstract
Bisphenol A (BPA) is one of the most widely used and versatile chemical compounds in polymer additives and epoxy resins for manufacturing a range of products for human applications. It is known as endocrine disruptor, however, there is growing evidence that it is genotoxic. Because of its adverse effects, the European Union has restricted its use to protect human health and the environment. As a result, the industry has begun developing BPA analogues, but there are not yet sufficient toxicity data to claim that they are safe. We investigated the adverse toxic effects of BPA and its analogues (BPS, BPAP, BPAF, BPFL, and BPC) with emphasis on their cytotoxic and genotoxic activities after short (24-h) and prolonged (96-h) exposure in in vitro hepatic three-dimensional cell model developed from HepG2 cells. The results showed that BPFL and BPC (formed by an additional ring system) were the most cytotoxic analogues that affected cell viability, spheroid surface area and morphology, cell proliferation, and apoptotic cell death. BPA, BPAP, and BPAF induced DNA double-strand break formation (γH2AX assay), whereas BPAF and BPC increased the percentage of p-H3-positive cells, indicating their aneugenic activity. All BPs induced DNA single-strand break formation (comet assay), with BPAP (≥0.1 μM) being the most effective and BPA and BPC the least effective (≥1 μM) under conditions applied. The results indicate that not all of the analogues studied are safer alternatives to BPA and thus more in-depth research is urgently needed to adequately evaluate the risks of BPA analogues and assess their safety for humans., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2023
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39. Characterisation and toxicological activity of three different Pseudo-nitzschia species from the northern Adriatic Sea (Croatia).
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Smodlaka Tanković M, Baričević A, Gerić M, Domijan AM, Pfannkuchen DM, Kužat N, Ujević I, Kuralić M, Rožman M, Matković K, Novak M, Žegura B, Pfannkuchen M, and Gajski G
- Subjects
- Croatia, Harmful Algal Bloom, Humans, Diatoms genetics, Diatoms metabolism
- Abstract
Diatoms of the genus Pseudo-nitzschia are cosmopolitans spread in seas and oceans worldwide, with more than 50 described species, dozens of which have been confirmed to produce domoic acid (DA). Here, we characterized and investigated the toxicological activity of secondary metabolites excreted into the growth media of different Pseudo-nitzschia species sampled at various locations in the northern Adriatic Sea (Croatia) using human blood cells under in vitro conditions. The results revealed that three investigated species of the genus Pseudo-nitzschia were capable of producing DA indicating their toxic potential. Moreover, toxicological data suggested all three Pseudo-nitzschia species can excrete toxic secondary metabolites into the surrounding media in addition to the intracellular pools of DA, raising concerns regarding their toxicity and environmental impact. In addition, all three Pseudo-nitzchia species triggered oxidative stress, one of the mechanisms of action likely responsible for the DNA damage observed in human blood cells. In line with the above stated, our results are of great interest to environmental toxicologists, the public and policy makers, especially in light of today's climate change, which favours harmful algal blooms and the growth of DA producers with a presumed negative impact on the public health of coastal residents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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40. Marine toxin domoic acid induces moderate toxicological response in non-target HepG2 cells.
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Madunić J, Hercog K, Gerić M, Domijan AM, Žegura B, and Gajski G
- Subjects
- Animals, DNA metabolism, Hep G2 Cells, Humans, Kainic Acid analogs & derivatives, Kainic Acid toxicity, Mammals, Marine Toxins metabolism, Marine Toxins toxicity, Diatoms metabolism, Neurotoxins toxicity
- Abstract
Domoic acid (DA) is a marine neurotoxin produced as a defence compound by diatom Pseudo-nitzschia. Although its toxicity is well known in marine mammals and fish, data on DA cyto/genotoxicity in human non-target cells is still limited. Hence, we aimed to study the effect of DA (0.001-10 µg/mL) on cell viability and proliferation kinetics of human hepatocellular carcinoma (HepG2) cells as well as DNA damage induction after 4, 24 and 72 h of exposure. The results revealed that DA up to 10 µg/mL did not elicit significant changes in HepG2 cell viability, proliferation and cell cycle at applied conditions. DA did not generate DNA double-strand breaks, while it exhibited significant dose- and time-dependent increase of DNA damage in the form of either DNA single-strand breaks or alkali labile sites. Additionally, increased malondialdehyde level after DA treatment indicated oxidative damage to lipids. Altogether, the results showed that neurotoxin DA induced only minor adverse genotoxic effects in non-target HepG2 cells that most probably occurred resulting from the oxidative stress. However, additional research is needed to further elucidate the mechanisms of DA toxicity, particularly in terms of chronic exposure, as well as to understand its potential influence on human non-target cells., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
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41. HepG2 spheroids as a biosensor-like cell-based system for (geno)toxicity assessment.
- Author
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Štampar M, Žabkar S, Filipič M, and Žegura B
- Subjects
- DNA Damage, Hep G2 Cells, Humans, Benzo(a)pyrene toxicity, Biosensing Techniques
- Abstract
3D spheroids developed from HepG2 cells were used as a biosensor-like system for the detection of (geno)toxic effects induced by chemicals. Benzo(a)pyrene (B(a)P) and amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) with well-known mechanisms of action were used for system validation. HepG2 spheroids grown for 3 days were exposed to BaP and PhIP for 24 and 72 h. The growth and viability of spheroids were monitored by planimetry and Live/Dead staining of cells. Multi-parametric flow cytometric analysis was applied for simultaneous detection of specific end-effects including cell cycle analysis (Hoechst staining), cell proliferation (KI67 marker), and DNA double-strand breaks (ℽH2AX) induced by genotoxic compounds. Depending on the exposure concentration/time, BaP reduced spheroid growth, affected cell proliferation by arresting cells in S and G2 phase and induced DNA double-strand breaks (DSB). Simultaneous staining of ℽH2AX formation and cell cycle analysis revealed that after BaP (10 μM; 24 h) exposure 60% of cells in G0/G1 phase had DNA DSB, while after 72 h only 20% of cells contained DSB indicating efficient repair of DNA lesions. PhIP did not influence the spheroid size whereas accumulation of cells in the G2 phase occurred after both treatment times. The evaluation of DNA damage revealed that at 200 μM PhIP 50% of cells in G0/G1 phase had DNA DSB, which after 72-h exposure dropped to 40%, showing lower repair capacity of PhIP-induced DSB compared to BaP-induced. The developed approach using simultaneous detection of several parameters provides mechanistic data and thus contributes to more reliable genotoxicity assessment of chemicals as a high-content screening tool., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2022
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42. Photodegradation, toxicity and density functional theory study of pharmaceutical metoclopramide and its photoproducts.
- Author
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Dabić D, Hanževački M, Škorić I, Žegura B, Ivanković K, Biošić M, Tolić K, and Babić S
- Subjects
- Density Functional Theory, Ferric Compounds, Kinetics, Metoclopramide toxicity, Photolysis, Sunlight, Pharmaceutical Preparations, Water Pollutants, Chemical analysis, Water Pollutants, Chemical toxicity
- Abstract
Pharmaceuticals as ubiquitous organic pollutants in the aquatic environment represent substances whose knowledge of environmental fate is still limited. One such compound is metoclopramide, whose direct and indirect photolysis and toxicological assessment have been studied for the first time in this study. Experiments were performed under solar radiation, showing metoclopramide as a compound that can easily degrade in different water matrices. The effect of pH-values showed the faster degradation at pH = 7, while the highly alkaline conditions at pH = 11 slowed photolysis. The highest value of quantum yield of metoclopramide photodegradation (ϕ = 43.55·10
-4 ) was obtained at pH = 7. Various organic and inorganic substances (NO3 - , Fe(III), HA, Cl- , Br- , HCO3 - , SO4 2- ), commonly present in natural water, inhibited the degradation by absorbing light. In all experiments, kinetics followed pseudo-first-order reaction with r2 greater than 0.98. The structures of the photolytic degradation products were tentatively identified, and degradation photoproducts were proposed. The hydroxylation of the aromatic ring and the amino group's dealkylation were two major photoproduct formation mechanisms. Calculated thermochemical quantities are in agreement with the experimentally observed stability of different photoproducts. Reactive sites in metoclopramide were studied with conceptual density functional theory and regions most susceptible to• OH attack were characterized. Metoclopramide and its degradation products were neither genotoxic for bacteria Salmonella typhimurium in the SOS/umuC assay nor acutely toxic for bacteria Vibrio fischeri., Competing Interests: Declaration of competing interest The authors confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2022
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43. Effects of tyrosine kinase inhibitors on androgen, estrogen α, glucocorticoid and thyroid receptors.
- Author
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Kenda M, Avsec D, Zore T, Kogovšek E, Pečar Fonović U, Kos J, Bozovičar K, Bratkovič T, Karas Kuželički N, Žegura B, Filipič M, and Sollner Dolenc M
- Subjects
- Androgen Receptor Antagonists, Animals, Cell Line, Gene Expression Regulation drug effects, Humans, Receptors, Androgen genetics, Receptors, Androgen metabolism, Thyroid Hormones, Antineoplastic Agents pharmacology, Antithyroid Agents pharmacology, Estrogen Receptor alpha antagonists & inhibitors, Protein-Tyrosine Kinases antagonists & inhibitors, Receptors, Glucocorticoid antagonists & inhibitors
- Abstract
Modern anticancer therapies favor a targeted approach. Tyrosine kinase inhibitors (TKIs) are drugs that target molecular pathways involved in various types of malignancies. Although TKIs are safe and well tolerated, they remain not completely selective; e.g., endocrine-mediated adverse events have been observed with their use. In the present study, the effects of seven TKIs were determined on the activities of androgen receptor, estrogen receptor α (ERα), glucocorticoid receptor and thyroid receptor in vitro using stably transfected cell lines expressing firefly luciferase reporter gene: AR-EcoScreen, hERα-HeLa9903, MDA-kb2, and GH3.TRE-Luc cells, respectively. Antiandrogenic activity was seen for erlotinib, estrogenic activity for imatinib, antiestrogenic activity for dasatinib, erlotinib, nilotinib, regorafenib and sorafenib, glucocorticoid activity for erlotinib and ibrutinib, antiglucocorticoid activity for regorafenib and sorafenib, and antithyroid activity for ibrutinib. Additionally, synergism was seen for 1-5 μM dasatinib and 500 nM hydrocortisone combination for glucocorticoid activity in MDA-kb2 cells. The estrogenic activity of imatinib was confirmed as mediated through ERα, and interference of the TKIs with the reporter gene assays was ruled out in a cell-lysate-based firefly luciferase enzyme inhibition assay. Imatinib in combination with 4-hydroxytamoxifen showed concentration-dependent effects on the metabolic activity of ERα-expressing AN3CA, MCF-7, and SKOV3 cells, and on cell proliferation and adhesion of MCF-7 cells. These findings contribute to the understanding of the endocrine effects of TKIs, in terms of toxicity and effectiveness, and define the need to further evaluate the endocrine disrupting activities of TKIs to safeguard human and environmental health., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2022
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44. Lethal and Sub-Lethal Effects and Modulation of Gene Expression Induced by T Kinase Inhibitors in Zebrafish (Danio Rerio) Embryos.
- Author
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Elersek T, Novak M, Mlinar M, Virant I, Bahor N, Leben K, Žegura B, and Filipič M
- Abstract
Tyrosine kinase inhibitors (TKIs) are designed for targeted cancer therapy. The consumption of these drugs during the last 20 years has been constantly rising. In the zebrafish ( Danio rerio ) embryo toxicity test, we assessed the toxicity of six TKIs: imatinib mesylate, erlotinib, nilotinib, dasatinib, sorafenib and regorafenib. Imatinib mesylate and dasatinib induced lethal effects, while regorafenib, sorfenib and dasatinib caused a significant increase of sub-lethal effects, predominantly oedema, no blood circulation and formation of blood aggregates. The analyses of the changes in the expression of selected genes associated with the hormone system after the exposure to imatinib mesylate, dasatinib and regorafenib demonstrated that all three tested TKIs deregulated the expression of oestrogen receptor esr1, cytochrome P450 aromatase (cypa19b) and hydroxysteroid-dehydrogenase (hsd3b), regorafenib, and also thyroglobulin (tg). The expression of genes involved in the DNA damage response (gadd45 and mcm6) and apoptosis (bcl2) was deregulated only by exposure to regorafenib. The data indicate that common mechanisms, namely antiangiogenic activity and interference with steroidogenesis are involved in the TKI induced sub-lethal effects and potential hormone disrupting activity, respectively. The residues of TKIs may represent an environmental hazard; therefore, further ecotoxicological studies focusing also on the effects of their mixtures are warranted.
- Published
- 2021
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45. Genotoxic activity of endocrine disrupting compounds commonly present in paper mill effluents.
- Author
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Balabanič D, Filipič M, Krivograd Klemenčič A, and Žegura B
- Subjects
- Benzhydryl Compounds analysis, Comet Assay, DNA Damage, Dibutyl Phthalate, Humans, Wastewater, Endocrine Disruptors analysis, Endocrine Disruptors toxicity, Phthalic Acids
- Abstract
In the present study we evaluated cytotoxic and genotoxic activities of endocrine disrupting compounds (EDCs), including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), and nonylphenol (NP), which have been previously identified in effluents from two paper mills with different paper production technologies (virgin or recycled fibres). Moreover, we evaluated genotoxic activity of the effluents from these two paper mills and compared it to the activity of artificial complex mixtures consisting of the seven EDCs at concentrations detected in corresponding paper mill effluents. None of the EDCs was genotoxic in Salmonella typhimurium (SOS/umuC assay), while all induced DNA damage in human hepatocellular carcinoma (HepG2) cells (comet assay). After 4 h of exposure genotoxic effects were determined at concentrations ≥ 1 μg/L for BBP and DEHP, ≥10 μg/L for DMP, DEP, DBP, and BPA, and ≥100 μg/L for NP, while after 24 h of exposure DNA damage occurred at ≥10 μg/L for DBP, BPA and NP, and ≥100 μg/L for DMP, DEP, BBP and DEHP. The effluents and corresponding artificial mixtures of EDCs from paper mill that uses virgin fibres did not induce DNA damage in HepG2 cells, while the effluents and corresponding artificial mixtures for the paper mill that uses recycled fibres were genotoxic. Genotoxic activity of effluents was significantly higher compared to corresponding artificial mixtures suggesting the presence of further unknown compounds contributing to the effect. Wastewater monitoring based on chemical analysis is limited to determination of targeted compounds and does not take into account possible interactions between chemicals in mixtures. Therefore, it alone cannot provide an adequate information on potential toxic effects required for the assessment of genotoxic activity of real environmental samples and their potential threats to the environment and human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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46. Polysaccharide-Based Bilayer Coatings for Biofilm-Inhibiting Surfaces of Medical Devices.
- Author
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Ajdnik U, Luxbacher T, Vesel A, Štern A, Žegura B, Trček J, and Fras Zemljič L
- Abstract
Chitosan (Chi) and 77KS, a lysine-derived surfactant, form polyelectrolyte complexes that reverse their charge from positive to negative at higher 77KS concentrations, forming aggregates that have been embedded with amoxicillin (AMOX). Dispersion of this complex was used to coat polydimethylsiloxane (PDMS) films, with an additional layer of anionic and hydrophilic hyaluronic acid (HA) as an outer adsorbate layer to enhance protein repulsion in addition to antimicrobial activity by forming a highly hydrated layer in combination with steric hindrance. The formed polysaccharide-based bilayer on PDMS was analyzed by water contact angle measurements, X-ray photoelectron spectroscopy (XPS), and surface zeta ( ζ )-potential. All measurements show the existence and adhesion of the two layers on the PDMS surface. Part of this study was devoted to understanding the underlying protein adsorption phenomena and identifying the mechanisms associated with biofouling. Thus, the adsorption of a mixed-protein solution (bovine serum albumin, fibrinogen, γ-globulin) on PDMS surfaces was studied to test the antifouling properties. The adsorption experiments were performed using a quartz crystal microbalance with dissipation monitoring (QCM-D) and showed improved antifouling properties by these polysaccharide-based bilayer coatings compared to a reference or for only one layer, i.e., the complex. This proves the benefit of a second hyaluronic acid layer. Microbiological and biocompatibility tests were also performed on real samples, i.e., silicone discs, showing the perspective of the prepared bilayer coating for medical devices such as prostheses, catheters (balloon angioplasty, intravascular), delivery systems (sheaths, implants), and stents.
- Published
- 2021
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47. Chemoprotective Effects of Xanthohumol against the Carcinogenic Mycotoxin Aflatoxin B1.
- Author
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Štern A, Furlan V, Novak M, Štampar M, Kolenc Z, Kores K, Filipič M, Bren U, and Žegura B
- Abstract
The present study addresses the chemoprotective effects of xanthohumol (XN), a prenylated flavonoid found in the female inflorescences (hops) of the plant Humulus lupulus L., against the carcinogenic food contaminant aflatoxin B1 (AFB1). The chemical reactions of XN and its derivatives (isoxanthohumol (IXN), 8-prenylnaringenin (8-PN), and 6-prenylnaringenin (6-PN)) with the AFB1 metabolite, aflatoxin B1 exo-8,9-epoxide (AFBO), were investigated in silico , by calculating activation free energies (ΔG
‡ ) at the Hartree-Fock level of theory in combination with the 6-311++G(d,p) basis set and two implicit solvation models. The chemoprotective effects of XN were investigated in vitro in the metabolically competent HepG2 cell line, analyzing its influence on AFB1-induced cytotoxicity using the MTS assay, genotoxicity using the comet and γH2AX assays, and cell cycle modulation using flow cytometry. Our results show that the ΔG‡ required for the reactions of XN and its derivatives with AFBO are comparable to the ΔG‡ required for the reaction of AFBO with guanine, indicating that XN, IXN, 8-PN, and 6-PN could act as scavengers of AFBO, preventing DNA adduct formation and DNA damage induction. This was also reflected in the results from the in vitro experiments, where a reduction in AFB1-induced cytotoxicity and DNA single-strand and double-strand breaks was observed in cells exposed to combinations of AFB1 and XN, highlighting the chemoprotective effects of this phytochemical.- Published
- 2021
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48. 3D Pharmacophore-Based Discovery of Novel K V 10.1 Inhibitors with Antiproliferative Activity.
- Author
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Toplak Ž, Hendrickx LA, Gubič Š, Možina Š, Žegura B, Štern A, Novak M, Shi X, Peigneur S, Tytgat J, Tomašič T, Pardo LA, and Mašič LP
- Abstract
(1) Background: The voltage-gated potassium channel K
V 10.1 (Eag1) is considered a near- universal tumour marker and represents a promising new target for the discovery of novel anticancer drugs. (2) Methods: We utilized the ligand-based drug discovery methodology using 3D pharmacophore modelling and medicinal chemistry approaches to prepare a novel structural class of KV 10.1 inhibitors. Whole-cell patch clamp experiments were used to investigate potency, selectivity, kinetics and mode of inhibition. Anticancer activity was determined using 2D and 3D cell-based models. (3) Results: The virtual screening hit compound ZVS-08 discovered by 3D pharmacophore modelling exhibited an IC50 value of 3.70 µM against KV 10.1 and inhibited the channel in a voltage-dependent manner consistent with the action of a gating modifier. Structural optimization resulted in the most potent KV 10.1 inhibitor of the series with an IC50 value of 740 nM, which was potent on the MCF-7 cell line expressing high KV 10.1 levels and low hERG levels, induced significant apoptosis in tumour spheroids of Colo-357 cells and was not mutagenic. (4) Conclusions: Computational ligand-based drug design methods can be successful in the discovery of new potent KV 10.1 inhibitors. The main problem in the field of KV 10.1 inhibitors remains selectivity against the hERG channel, which needs to be addressed in the future also with target-based drug design methods.- Published
- 2021
- Full Text
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49. Hepatocellular carcinoma (HepG2/C3A) cell-based 3D model for genotoxicity testing of chemicals.
- Author
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Štampar M, Sedighi Frandsen H, Rogowska-Wrzesinska A, Wrzesinski K, Filipič M, and Žegura B
- Subjects
- Comet Assay, DNA Damage, Humans, Mutagenicity Tests, Mutagens toxicity, Carcinoma, Hepatocellular, Liver Neoplasms
- Abstract
The major weakness of the current in vitro genotoxicity test systems is the inability of the indicator cells to express metabolic enzymes needed for the activation and detoxification of genotoxic compounds, which consequently can lead to misleading results. Thus, there is a significant emphasis on developing hepatic cell models, including advanced in vitro three-dimensional (3D) cell-based systems, which better imitate in vivo cell behaviour and offer more accurate and predictive data for human exposures. In this study, we developed an approach for genotoxicity testing with 21-day old spheroids formed from human hepatocellular carcinoma cells (HepG2/C3A) using the dynamic clinostat bioreactor system (CelVivo BAM/bioreactor) under controlled conditions. The spheroids were exposed to indirect-acting genotoxic compounds, polycyclic aromatic hydrocarbon [PAH; benzo(a) pyrene B(a)P], and heterocyclic aromatic amine [PhIP]) at non-cytotoxic concentrations for 24 and 96 h. The results showed that both environmental pollutants B(a)P and PhIP significantly increased the level of DNA strand breaks assessed by the comet assay. Further, the mRNA level of selected genes encoding metabolic enzymes from phase I and II, and DNA damage responsive genes was determined (qPCR). The 21-day old spheroids showed higher basal expression of genes encoding metabolic enzymes compared to monolayer culture. In spheroids, B(a)P or PhIP induced compound-specific up-regulation of genes implicated in their metabolism, and deregulation of genes implicated in DNA damage and immediate-early response. The study demonstrated that this model utilizing HepG2/C3A spheroids grown under dynamic clinostat conditions represents a very sensitive and promising in vitro model for genotoxicity and environmental studies and can thus significantly contribute to a more reliable assessment of genotoxic activities of pure chemicals, and complex environmental samples even at very low for environmental exposure relevant concentrations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
50. Unravelling the pathways of air plasma induced aflatoxin B 1 degradation and detoxification.
- Author
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Hojnik N, Modic M, Walsh JL, Žigon D, Javornik U, Plavec J, Žegura B, Filipič M, and Cvelbar U
- Subjects
- Aflatoxin B1 toxicity, Humans, Mass Spectrometry, Aflatoxins, Carcinoma, Hepatocellular, Liver Neoplasms
- Abstract
Aflatoxins are considered to be a critical dietary risk factor for humans, with aflatoxin B
1 (AFB1 ) identified by the WHO as one of the most potent natural group 1 carcinogen. Despite this, more than half of the world's population is chronically exposed, resulting in up to 170,000 annual cases of human hepatocellular carcinoma cancer. Here we report an easily implemented approach using non-equilibrium plasma for targeted degradation of AFB1 . Apart from reaching the 100 % decontamination in less than 120 s of treatment, this is the first study that combines hypersensitive analytical methods such as high-resolution mass spectroscopy (HRMS) and nuclear magnetic resonance spectroscopy (NMR) to provide a detailed description of CAP mediated AFB1 degradation. We identify rapid scission of the vinyl bond between 8- and 9-position on the terminal furan ring of AFB1 as being of paramount importance for the suppression of toxic potential, which is confirmed by the examination of both cytotoxicity and genotoxicity. The plasma reactive species mediated degradation pathways are elucidated, and it is demonstrated that the approach not only renders AFB1 harmless but does so in order of magnitude less time than UV irradiation as one of the other non-thermal methods currently under investigation., (Copyright © 2020 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
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