5-Aminoisophthalic acid and 5-nitroisophthalic acid (5-NIPA) are potential impurities in preparations of 5-amino-2,4,6-triiodoisophthalic acid, which is a key intermediate in the synthesis of the iodinated contrast agent iopamidol. We have studied their mutagenicity in silico (quantitative structure-activity relationships, QSAR) and by the bacterial reverse mutation assay (Ames test). First, the compounds were screened with the tools Derek Nexus™ and Leadscope®. Both compounds were flagged as potentially mutagenic (class 3 under ICH M7). However, contrary to the in silico prediction, neither chemical was mutagenic in the Ames test (plate incorporation method) with or without S9 metabolic activation.
{"title":"Mutagenicity assessment of two potential impurities in preparations of 5-amino-2,4,6 triiodoisophthalic acid, a key intermediate in the synthesis of the iodinated contrast agent iopamidol","authors":"Silvia Rossi , Simona Bussi , Roberta Bonafè , Carola Incardona , Emanuela Vurro , Massimo Visigalli , Federica Buonsanti , Roberta Fretta","doi":"10.1016/j.mrgentox.2023.503720","DOIUrl":"https://doi.org/10.1016/j.mrgentox.2023.503720","url":null,"abstract":"<div><p>5-Aminoisophthalic acid and 5-nitroisophthalic acid (5-NIPA) are potential impurities in preparations of 5-amino-2,4,6-triiodoisophthalic acid, which is a key intermediate in the synthesis of the iodinated contrast agent iopamidol. We have studied their mutagenicity <em>in silico</em> (quantitative structure-activity relationships, QSAR) and by the bacterial reverse mutation assay (Ames test). First, the compounds were screened with the tools Derek Nexus™ and Leadscope®. Both compounds were flagged as potentially mutagenic (class 3 under ICH M7). However, contrary to the <em>in silico</em> prediction, neither chemical was mutagenic in the Ames test (plate incorporation method) with or without S9 metabolic activation.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1383571823001389/pdfft?md5=685f5f9623b3c76ab72a40ecd22f5300&pid=1-s2.0-S1383571823001389-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138475185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sucrose and high-fructose corn syrup comprise nearly equal amounts of glucose and fructose. With the use of high-fructose corn syrup in the food industry, consumption of fructose, which may be a tumor promoter, has increased dramatically. We examined fructose-induced oxidative DNA damage in the presence of Cu(II), with or without the addition of H2O2. With isolated DNA, fructose induced Cu(II)-mediated DNA damage, including formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), to a greater extent than did glucose, and H2O2 enhanced the damage. In cultured human cells, 8-oxodG formation increased significantly following treatment with fructose and the H2O2-generating enzyme glucose oxidase. Fructose may play an important role in oxidative DNA damage, suggesting a possible mechanism for involvement of fructose in carcinogenesis.
蔗糖和高果糖玉米糖浆由几乎等量的葡萄糖和果糖组成。随着高果糖玉米糖浆在食品工业中的使用,果糖的消费量急剧增加,而果糖可能是一种肿瘤促进剂。我们研究了果糖在有 Cu(II)存在、添加或不添加 H2O2 的情况下诱导的 DNA 氧化损伤。在分离的 DNA 中,果糖诱导 Cu(II)介导的 DNA 损伤(包括 8-氧代-7,8-二氢-2′-脱氧鸟苷(8-oxodG)的形成)的程度高于葡萄糖,而 H2O2 会增强这种损伤。在培养的人体细胞中,果糖和产生 H2O2 的葡萄糖氧化酶处理后,8-oxodG 的形成显著增加。果糖可能在 DNA 氧化损伤中发挥了重要作用,这表明果糖参与致癌的可能机制。
{"title":"Oxidative DNA damage: Induction by fructose, in vitro, and its enhancement by hydrogen peroxide","authors":"Kaoru Midorikawa , Kokoro Kobayashi , Shinya Kato , Shosuke Kawanishi , Hatasu Kobayashi , Shinji Oikawa , Mariko Murata","doi":"10.1016/j.mrgentox.2023.503719","DOIUrl":"https://doi.org/10.1016/j.mrgentox.2023.503719","url":null,"abstract":"<div><p>Sucrose and high-fructose corn syrup comprise nearly equal amounts of glucose and fructose. With the use of high-fructose corn syrup in the food industry, consumption of fructose, which may be a tumor promoter, has increased dramatically. We examined fructose-induced oxidative DNA damage in the presence of Cu(II), with or without the addition of H<sub>2</sub>O<sub>2</sub>. With isolated DNA, fructose induced Cu(II)-mediated DNA damage, including formation of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), to a greater extent than did glucose, and H<sub>2</sub>O<sub>2</sub> enhanced the damage. In cultured human cells, 8-oxodG formation increased significantly following treatment with fructose and the H<sub>2</sub>O<sub>2</sub>-generating enzyme glucose oxidase. Fructose may play an important role in oxidative DNA damage, suggesting a possible mechanism for involvement of fructose in carcinogenesis.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1383571823001377/pdfft?md5=366d6e8e7fd41824a49d9c535ffb2158&pid=1-s2.0-S1383571823001377-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138489967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Ames MPF™ is a miniaturized, microplate fluctuation format of the Ames test. It is a standardized, commercially available product which can be used to assess mutagenicity in Salmonella and E. coli strains in 384-well plates using a color change-based readout. Several peer-reviewed comparisons of the Ames MPF™ to the Ames test in Petri dishes confirmed its suitability to evaluate the mutagenic potential of a variety of test items. An international multicenter study involving seven laboratories tested six coded chemicals with this assay using five bacterial strains, as recommended by the OECD test guideline 471. The data generated by the participating laboratories was in excellent agreement (93%), and the similarity of their dose response curves, as analyzed with sophisticated statistical approaches further confirmed the suitability of the Ames MPF™ assay as an alternative to the Ames test on agar plates, but with advantages with respect to significantly reduced amount of test substance and S9 requirements, speed, hands-on time and, potentially automation.
{"title":"Assessment of the performance of the Ames MPF™ assay: A multicenter collaborative study with six coded chemicals","authors":"Dimitrios Spiliotopoulos , Cécile Koelbert , Marc Audebert , Ilona Barisch , Deborah Bellet , Mathilde Constans , Andreas Czich , Francis Finot , Véronique Gervais , Laure Khoury , Christian Kirchnawy , Sachiko Kitamoto , Audrey Le Tesson , Laure Malesic , Ryoko Matsuyama , Elisa Mayrhofer , Isabelle Mouche , Birgit Preikschat , Lukas Prielinger , Bernhard Rainer , Kerstin Wäse","doi":"10.1016/j.mrgentox.2023.503718","DOIUrl":"https://doi.org/10.1016/j.mrgentox.2023.503718","url":null,"abstract":"<div><p><span><span>The Ames MPF™ is a miniaturized, microplate fluctuation format of the </span>Ames test<span>. It is a standardized, commercially available product which can be used to assess mutagenicity in </span></span><em>Salmonella</em> and <em>E. coli</em><span> strains in 384-well plates using a color change-based readout. Several peer-reviewed comparisons of the Ames MPF™ to the Ames test in Petri dishes confirmed its suitability to evaluate the mutagenic potential of a variety of test items. An international multicenter study involving seven laboratories tested six coded chemicals with this assay using five bacterial strains, as recommended by the OECD test guideline 471. The data generated by the participating laboratories was in excellent agreement (93%), and the similarity of their dose response curves, as analyzed with sophisticated statistical approaches further confirmed the suitability of the Ames MPF™ assay as an alternative to the Ames test on agar plates, but with advantages with respect to significantly reduced amount of test substance and S9 requirements, speed, hands-on time and, potentially automation.</span></p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138490976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1016/j.mrgentox.2023.503708
Nathalie Oestreicher , Jean-Paul Bourdineaud , Christian Vélot
Glyphosate-based herbicides (GBH) are the most used pesticides worldwide. This widespread dissemination raises the question of non-target effects on a wide range of organisms, including soil micro-organisms. Despite a large body of scientific studies reporting the harmful effects of GBHs, the health and environmental safety of glyphosate and its commercial formulations remains controversial. In particular, contradictory results have been obtained on the possible genotoxicity of these herbicides depending on the organisms or biological systems tested, the modes and durations of exposure and the sensitivity of the detection technique used. We previously showed that the well-characterized soil filamentous fungus Aspergillus nidulans was highly affected by a commercial GBH formulation containing 450 g/L of glyphosate (R450), even when used at doses far below the agricultural application rate. In the present study, we analysed the possible mutagenicity of R450 in A. nidulans by screening for specific mutants after different modes of exposure to the herbicide. R450 was found to exert a mutagenic effect only after repeated exposure during growth on agar-medium, and depending on the metabolic status of the tested strain. The nature of some mutants and their ability to tolerate the herbicide better than did the wild-type strain suggested that their emergence may reflect an adaptive response of the fungus to offset the herbicide effects. The use of a non-selective molecular approach, the quantitative random amplified polymorphic DNA (RAPD-qPCR), showed that R450 could also exert a mutagenic effect after a one-shot overnight exposure during growth in liquid culture. However, this effect was subtle and no longer detectable when the fungus had previously been repeatedly exposed to the herbicide on a solid medium. This indicated an elevation of the sensitivity threshold of A. nidulans to the R450 mutagenicity, and thus confirmed the adaptive capacity of the fungus to the herbicide.
{"title":"Mutagenic effects of a commercial glyphosate-based herbicide formulation on the soil filamentous fungus Aspergillus nidulans depending on the mode of exposure","authors":"Nathalie Oestreicher , Jean-Paul Bourdineaud , Christian Vélot","doi":"10.1016/j.mrgentox.2023.503708","DOIUrl":"https://doi.org/10.1016/j.mrgentox.2023.503708","url":null,"abstract":"<div><p>Glyphosate-based herbicides (GBH) are the most used pesticides worldwide. This widespread dissemination raises the question of non-target effects on a wide range of organisms, including soil micro-organisms. Despite a large body of scientific studies reporting the harmful effects of GBHs, the health and environmental safety of glyphosate and its commercial formulations remains controversial. In particular, contradictory results have been obtained on the possible genotoxicity of these herbicides depending on the organisms or biological systems tested, the modes and durations of exposure and the sensitivity of the detection technique used. We previously showed that the well-characterized soil filamentous fungus <em>Aspergillus nidulans</em> was highly affected by a commercial GBH formulation containing 450 g/L of glyphosate (R450), even when used at doses far below the agricultural application rate. In the present study, we analysed the possible mutagenicity of R450 in <em>A. nidulans</em> by screening for specific mutants after different modes of exposure to the herbicide. R450 was found to exert a mutagenic effect only after repeated exposure during growth on agar-medium, and depending on the metabolic status of the tested strain. The nature of some mutants and their ability to tolerate the herbicide better than did the wild-type strain suggested that their emergence may reflect an adaptive response of the fungus to offset the herbicide effects. The use of a non-selective molecular approach, the quantitative random amplified polymorphic DNA (RAPD-qPCR), showed that R450 could also exert a mutagenic effect after a one-shot overnight exposure during growth in liquid culture. However, this effect was subtle and no longer detectable when the fungus had previously been repeatedly exposed to the herbicide on a solid medium. This indicated an elevation of the sensitivity threshold of <em>A. nidulans</em> to the R450 mutagenicity, and thus confirmed the adaptive capacity of the fungus to the herbicide.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92039589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-18DOI: 10.1016/j.mrgentox.2023.503707
Sabry M. Attia, Sheikh F. Ahmad, Ahmed Nadeem, Mohamed S.M. Attia, Mushtaq A. Ansari, Abdelkader E. Ashour, Norah A. Albekairi, Mohammed A. Al-Hamamah, Ali A. Alshamrani, Saleh A. Bakheet
Diabetes-related complications are becoming increasingly common as the global prevalence of diabetes increases. Diabetes is also linked to a high risk of developing cancer. This raises the question of whether cancer vulnerability is caused by diabetes itself or the use of antidiabetic drugs. Chromosomal instability, a source of genetic modification involving either an altered chromosomal number or structure, is a hallmark of cancer. Saxagliptin has been approved by the FDA for diabetes treatment. However, the detailed in vivo effects of prolonged saxagliptin treatment on chromosomal instability have not yet been reported. In this study, streptozotocin was used to induce diabetes in mice, and both diabetic and non-diabetic mice received saxagliptin for five weeks. Fluorescence in situ hybridization was conducted in combination with a bone marrow micronucleus test for measuring chromosomal instability. Our results indicated that saxagliptin is neither mutagenic nor cytotoxic, under the given treatment regimen. Diabetic mice had a much higher incidence of micronuclei formation, and a centromeric DNA probe was present inside the majority of the induced micronuclei, indicating that most of these were caused by chromosome nondisjunction. Conversely, diabetic mice treated with saxagliptin exhibited a significant decrease in micronuclei induction, which were centromeric-positive and centromeric-negative. Diabetes also causes significant biochemical changes indicative of oxidative stress, such as increased lipid peroxidation and decreased reduced/oxidized glutathione ratio, which was reversed by saxagliptin administration. Overall, saxagliptin, the non-mutagenic antidiabetic drug, maintains chromosomal integrity in diabetes and reduces micronuclei formation by restoring redox imbalance, further indicating its usefulness in diabetic patients.
{"title":"Saxagliptin, a selective dipeptidyl peptidase-4 inhibitor, alleviates somatic cell aneugenicity and clastogenicity in diabetic mice","authors":"Sabry M. Attia, Sheikh F. Ahmad, Ahmed Nadeem, Mohamed S.M. Attia, Mushtaq A. Ansari, Abdelkader E. Ashour, Norah A. Albekairi, Mohammed A. Al-Hamamah, Ali A. Alshamrani, Saleh A. Bakheet","doi":"10.1016/j.mrgentox.2023.503707","DOIUrl":"https://doi.org/10.1016/j.mrgentox.2023.503707","url":null,"abstract":"<div><p>Diabetes-related complications are becoming increasingly common as the global prevalence of diabetes increases. Diabetes is also linked to a high risk of developing cancer. This raises the question of whether cancer vulnerability is caused by diabetes itself or the use of antidiabetic drugs. Chromosomal instability, a source of genetic modification involving either an altered chromosomal number or structure, is a hallmark of cancer. Saxagliptin has been approved by the FDA for diabetes treatment. However, the detailed <em>in vivo</em> effects of prolonged saxagliptin treatment on chromosomal instability have not yet been reported. In this study, streptozotocin was used to induce diabetes in mice, and both diabetic and non-diabetic mice received saxagliptin for five weeks. Fluorescence <em>in situ</em> hybridization was conducted in combination with a bone marrow micronucleus test for measuring chromosomal instability. Our results indicated that saxagliptin is neither mutagenic nor cytotoxic, under the given treatment regimen. Diabetic mice had a much higher incidence of micronuclei formation, and a centromeric DNA probe was present inside the majority of the induced micronuclei, indicating that most of these were caused by chromosome nondisjunction. Conversely, diabetic mice treated with saxagliptin exhibited a significant decrease in micronuclei induction, which were centromeric-positive and centromeric-negative. Diabetes also causes significant biochemical changes indicative of oxidative stress, such as increased lipid peroxidation and decreased reduced/oxidized glutathione ratio, which was reversed by saxagliptin administration. Overall, saxagliptin, the non-mutagenic antidiabetic drug, maintains chromosomal integrity in diabetes and reduces micronuclei formation by restoring redox imbalance, further indicating its usefulness in diabetic patients.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49849065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-14DOI: 10.1016/j.mrgentox.2023.503706
Stefana Vuletić , Marina Bekić , Sergej Tomić , Biljana Nikolić , Stefana Cvetković , Tea Ganić , Dragana Mitić-Ćulafić
Among numerous types of cancer, hepatocellular and colorectal carcinoma are important causes of mortality. Given the nature of these cancer types and their resistance, it is of great importance to find new chemotherapeutics and therapy targets, so plant products seem to be an excellent choice in such search. The main goal of this study was to investigate anticancer activity of Frangula alnus ethyl-acetate extract (FA) and its dominant constituent emodin (E) on hepatocellular and colorectal carcinoma cell lines, HepG2 and HCT116, as well as on normal MRC-5 fibroblasts. Cytotoxicity was investigated in MTT test and both FA and E showed strong reduction of cell viability in cancer cells. Flow cytometer analysis demonstrated that FA and E led to G1 phase arrest and slight accumulation of cells in the G2/M phase; additionally, annexinV-FITC/7AAD dying showed that FA and E decreased cell viability and triggered apoptosis in all cell lines. FA and E evidenced strong genotoxic potential in comet assay performed on all cell lines, while tests measuring antioxidative potential (DPPH and TBA) demonstrated strong effect of FA. It could be concluded that both FA and E have significant anticancer activity against hepatocellular and colorectal carcinoma cell lines HepG2 and HCT116, but notable selectivity was not observed.
{"title":"Could alder buckthorn (Frangula alnus Mill) be a source of chemotherapeutics effective against hepato- and colorectal carcinoma? An in vitro study","authors":"Stefana Vuletić , Marina Bekić , Sergej Tomić , Biljana Nikolić , Stefana Cvetković , Tea Ganić , Dragana Mitić-Ćulafić","doi":"10.1016/j.mrgentox.2023.503706","DOIUrl":"https://doi.org/10.1016/j.mrgentox.2023.503706","url":null,"abstract":"<div><p>Among numerous types of cancer, hepatocellular and colorectal carcinoma are important causes of mortality. Given the nature of these cancer types and their resistance, it is of great importance to find new chemotherapeutics and therapy targets, so plant products seem to be an excellent choice in such search. The main goal of this study was to investigate anticancer activity of <em>Frangula alnus</em> ethyl-acetate extract (FA) and its dominant constituent emodin (E) on hepatocellular and colorectal carcinoma cell lines, HepG2 and HCT116, as well as on normal MRC-5 fibroblasts. Cytotoxicity was investigated in MTT test and both FA and E showed strong reduction of cell viability in cancer cells. Flow cytometer analysis demonstrated that FA and E led to G1 phase arrest and slight accumulation of cells in the G2/M phase; additionally, annexinV-FITC/7AAD dying showed that FA and E decreased cell viability and triggered apoptosis in all cell lines. FA and E evidenced strong genotoxic potential in comet assay performed on all cell lines, while tests measuring antioxidative potential (DPPH and TBA) demonstrated strong effect of FA. It could be concluded that both FA and E have significant anticancer activity against hepatocellular and colorectal carcinoma cell lines HepG2 and HCT116, but notable selectivity was not observed.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49849069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-10DOI: 10.1016/j.mrgentox.2023.503705
Mohammad Alzaben , Regina Burve , Katrin Loeschner , Peter Møller , Martin Roursgaard
The ubiquitous pollution of plastic particles in most environmental matrices leads to concern about any potential adverse effects on human health. Most studies on the toxicological effect of nanoplastics has focused on standard particles of polystyrene. In reality humans are exposed to a large variety of different types and sizes of plastic material via oral intake and inhalation. In this study, we investigated the effect of polyethylene terephthalate (PET) nanoplastic particles from ground food containers from a supermarket. The aim was to investigate a possible link between exposure to PET nanoplastics and genotoxic response in a cell model of the human airway epithelial (A549) cells. Further, we investigated the combined effect of PET and chemicals known to alter the cellular redox state, as a model of partially compromised antioxidant defense system. DNA damage was assessed by the alkaline comet assay. The ground PET nanoplastics have a mean hydrodynamic diameter of 136 nm in water. The results showed that PET exposure led to increased reactive oxygen species production (approximately 30 % increase compared to unexposed cells). In addition, exposure to PET nanoplastic increased the level of DNA strand breaks (net increase = 0.10 lesions/106 base pair, 95 % confidence interval: 0.01, 0.18 lesions/106 base pair). Pre- or post-exposure to hydrogen peroxide or buthionine sulfoximine did not lead to a higher level of DNA damage. Overall, the study shows that exposure to PET nanoplastics increases both intracellular reactive oxygen production and DNA damage in A549 cells.
{"title":"Nanoplastics from ground polyethylene terephthalate food containers: Genotoxicity in human lung epithelial A549 cells","authors":"Mohammad Alzaben , Regina Burve , Katrin Loeschner , Peter Møller , Martin Roursgaard","doi":"10.1016/j.mrgentox.2023.503705","DOIUrl":"https://doi.org/10.1016/j.mrgentox.2023.503705","url":null,"abstract":"<div><p>The ubiquitous pollution of plastic particles in most environmental matrices leads to concern about any potential adverse effects on human health. Most studies on the toxicological effect of nanoplastics has focused on standard particles of polystyrene. In reality humans are exposed to a large variety of different types and sizes of plastic material via oral intake and inhalation. In this study, we investigated the effect of polyethylene terephthalate (PET) nanoplastic particles from ground food containers from a supermarket. The aim was to investigate a possible link between exposure to PET nanoplastics and genotoxic response in a cell model of the human airway epithelial (A549) cells. Further, we investigated the combined effect of PET and chemicals known to alter the cellular redox state, as a model of partially compromised antioxidant defense system. DNA damage was assessed by the alkaline comet assay. The ground PET nanoplastics have a mean hydrodynamic diameter of 136 nm in water. The results showed that PET exposure led to increased reactive oxygen species production (approximately 30 % increase compared to unexposed cells). In addition, exposure to PET nanoplastic increased the level of DNA strand breaks (net increase = 0.10 lesions/10<sup>6</sup> base pair, 95 % confidence interval: 0.01, 0.18 lesions/10<sup>6</sup> base pair). Pre- or post-exposure to hydrogen peroxide or buthionine sulfoximine did not lead to a higher level of DNA damage. Overall, the study shows that exposure to PET nanoplastics increases both intracellular reactive oxygen production and DNA damage in A549 cells.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49849070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.1016/j.mrgentox.2023.503704
Mariana de Oliveira Klein , Luiza Flavia Veiga Francisco , Izabela Natália Faria Gomes , Sergio V. Serrano , Rui M. Reis , Henrique C.S. Silveira
Antineoplastic drugs are among the most toxic pharmaceuticals. Their release into the aquatic ecosystems has been reported, giving rise to concerns about the adverse effects, including cytotoxicity and genotoxicity, that they may have on exposed organisms. In this study, we analyzed the cytotoxicity and genotoxicity of 5-fluorouracil (5-FU) and its metabolite alpha-fluoro-beta-alanine (3-NH2-F); gemcitabine (GEM) and its metabolite 2′-deoxy-2′,2′-difluorouridine (2-DOH-DiF); as well as cyclophosphamide (CP) on the HepG2 cell line. Drug concentrations were based on those previously observed in the effluent of a major cancer hospital in Brazil. The study found that GEM, 2-DOH-DiF and 5-FU resulted in reduced cell viability. No reduction in cell viability was observed for CP and 3-NH2-F. Genotoxic assessment revealed damage in the form of nucleoplasmic bridges for CP and 3-NH2-F. The tested concentrations of all compounds resulted in significantly increased MNi and NBUDs. The results showed that these compounds induced cytotoxic and genotoxic effects in HepG2 cells at concentrations found in the environment. To the best of our knowledge, this study is the first to report on the cytogenotoxic impacts of the metabolites 3-NH2-F and 2-DOH-DiF in HepG2 cells. These findings may help in the development of public policies that could minimize potential environmental contamination.
{"title":"Hazard assessment of antineoplastic drugs and metabolites using cytotoxicity and genotoxicity assays","authors":"Mariana de Oliveira Klein , Luiza Flavia Veiga Francisco , Izabela Natália Faria Gomes , Sergio V. Serrano , Rui M. Reis , Henrique C.S. Silveira","doi":"10.1016/j.mrgentox.2023.503704","DOIUrl":"https://doi.org/10.1016/j.mrgentox.2023.503704","url":null,"abstract":"<div><p>Antineoplastic drugs are among the most toxic pharmaceuticals. Their release into the aquatic ecosystems has been reported, giving rise to concerns about the adverse effects, including cytotoxicity and genotoxicity, that they may have on exposed organisms. In this study, we analyzed the cytotoxicity and genotoxicity of 5-fluorouracil (5-FU) and its metabolite alpha-fluoro-beta-alanine (3-NH2-F); gemcitabine (GEM) and its metabolite 2′-deoxy-2′,2′-difluorouridine (2-DOH-DiF); as well as cyclophosphamide (CP) on the HepG2 cell line. Drug concentrations were based on those previously observed in the effluent of a major cancer hospital in Brazil. The study found that GEM, 2-DOH-DiF and 5-FU resulted in reduced cell viability. No reduction in cell viability was observed for CP and 3-NH2-F. Genotoxic assessment revealed damage in the form of nucleoplasmic bridges for CP and 3-NH2-F. The tested concentrations of all compounds resulted in significantly increased MNi and NBUDs. The results showed that these compounds induced cytotoxic and genotoxic effects in HepG2 cells at concentrations found in the environment. To the best of our knowledge, this study is the first to report on the cytogenotoxic impacts of the metabolites 3-NH2-F and 2-DOH-DiF in HepG2 cells. These findings may help in the development of public policies that could minimize potential environmental contamination.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49849064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1016/j.mrgentox.2023.503685
Joel P. Bercu , Shaofei Zhang , Zhanna Sobol , Patricia A. Escobar , Phu Van , Maik Schuler
N-Nitrosodiethylamine (NDEA), a well-studied N-nitrosamine, was tested in rats to compare the dose-response relationship of three genotoxicity endpoints. Mutant / mutation frequencies were determined using the transgenic rodent (TGR) gene mutation assay and error corrected next generation sequencing (ecNGS) (i.e., duplex sequencing (DS)), and genetic damage was detected by the alkaline comet assay. Big Blue® (cII Locus) animals (n = 6 per dose group) were administered doses of 0.001, 0.01, 0.1, 1, 3 mg/kg/day NDEA by oral gavage. Samples were collected for cII mutation and DS analyses following 28-days of exposure and 3 days recovery. In a separate study, male Sprague-Dawley (SD) rats (n = 6 per dose group) were administered the same doses by oral gavage for two consecutive days and then samples collected for the alkaline comet assay. A dose-related increase in mutant / mutation frequencies of the liver but not duodenum was observed using the TGR assay and DS with DS resulting in a slightly more sensitive response, with a lower benchmark dose (BMD). In addition, a dose-related increase in percent tail DNA was observed in the liver using the alkaline comet assay. Therefore, DS and comet assays showed good utility for hazard identification and dose-response analysis of a representative N-nitrosamine comparable to the TGR gene mutation assay.
{"title":"Comparison of the transgenic rodent mutation assay, error corrected next generation duplex sequencing, and the alkaline comet assay to detect dose-related mutations following exposure to N-nitrosodiethylamine","authors":"Joel P. Bercu , Shaofei Zhang , Zhanna Sobol , Patricia A. Escobar , Phu Van , Maik Schuler","doi":"10.1016/j.mrgentox.2023.503685","DOIUrl":"10.1016/j.mrgentox.2023.503685","url":null,"abstract":"<div><p><em>N</em>-Nitrosodiethylamine (NDEA), a well-studied <em>N</em>-nitrosamine, was tested in rats to compare the dose-response relationship of three genotoxicity endpoints. Mutant / mutation frequencies were determined using the transgenic rodent (TGR) gene mutation assay and error corrected next generation sequencing (ecNGS) (i.e., duplex sequencing (DS)), and genetic damage was detected by the alkaline comet assay. Big Blue® <em>(cII</em> Locus) animals (n = 6 per dose group) were administered doses of 0.001, 0.01, 0.1, 1, 3 mg/kg/day NDEA by oral gavage. Samples were collected for <em>cII</em> mutation and DS analyses following 28-days of exposure and 3 days recovery. In a separate study, male Sprague-Dawley (SD) rats (n = 6 per dose group) were administered the same doses by oral gavage for two consecutive days and then samples collected for the alkaline comet assay. A dose-related increase in mutant / mutation frequencies of the liver but not duodenum was observed using the TGR assay and DS with DS resulting in a slightly more sensitive response, with a lower benchmark dose (BMD). In addition, a dose-related increase in percent tail DNA was observed in the liver using the alkaline comet assay. Therefore, DS and comet assays showed good utility for hazard identification and dose-response analysis of a representative <em>N</em>-nitrosamine comparable to the TGR gene mutation assay.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41132165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-01DOI: 10.1016/j.mrgentox.2023.503680
Erik Bivehed , Björn Hellman , Yuting Fan , Jakob Haglöf , Sonja Buratovic
The effect of pH on DNA integrity was assessed using a three-step approach. The comet assay was used on a whole genome level, with three different protocols: neutral (no alkaline unwinding), flash (pH 12.5 with 2.5 min unwinding), and the conventional alkaline protocol (pH>13 with 40 min unwinding). Real-time quantitative PCR (RT-qPCR) was then used to study the isolated DNA, revealing that gene amplification decreased with increasing pH, indicating DNA degradation. Specially designed molecular beacons were used to examine DNA at the molecular level, with or without alkali-labile site (ALS) insertions. At pH 12.5, fluorescence in the hairpins with ALS started to increase after 30 min, while at pH> 13, this increase was already observed after 5 min, indicating a significant increase in DNA strand breaks. Liquid chromatography analysis was also used, demonstrating that the hairpins remained intact up to pH 10, even after 1 h exposure, whereas, at pH 12.5, partial conversion into strand breaks occurred after 30 min. At pH> 13, the hairpins were almost completely degraded after 30 min. The flash protocol effectively detects DNA single- and double-strand breaks and identified these damages after 2.5 min of alkaline treatment at pH 12.5. When the hairpins were exposed to pH 12.5 for 60 min, ALS were converted to strand breaks, demonstrating the sensitivity of this approach to detect changes in DNA structure. These findings indicate that pH poses a substantial risk to DNA integrity, leading to significantly higher background levels of DNA damage compared to conditions closer to neutrality. Our study demonstrates the importance of understanding the influence of pH on DNA stability and provides insights into risks associated with alkaline environments, especially at pH> 13.
{"title":"DNA integrity under alkaline conditions: An investigation of factors affecting the comet assay","authors":"Erik Bivehed , Björn Hellman , Yuting Fan , Jakob Haglöf , Sonja Buratovic","doi":"10.1016/j.mrgentox.2023.503680","DOIUrl":"10.1016/j.mrgentox.2023.503680","url":null,"abstract":"<div><p>The effect of pH on DNA integrity was assessed using a three-step approach. The comet assay was used on a whole genome level, with three different protocols: neutral (no alkaline unwinding), flash (pH 12.5 with 2.5 min unwinding), and the conventional alkaline protocol (pH>13 with 40 min unwinding). Real-time quantitative PCR (RT-qPCR) was then used to study the isolated DNA, revealing that gene amplification decreased with increasing pH, indicating DNA degradation. Specially designed molecular beacons were used to examine DNA at the molecular level, with or without alkali-labile site (ALS) insertions. At pH 12.5, fluorescence in the hairpins with ALS started to increase after 30 min, while at pH> 13, this increase was already observed after 5 min, indicating a significant increase in DNA strand breaks. Liquid chromatography analysis was also used, demonstrating that the hairpins remained intact up to pH 10, even after 1 h exposure, whereas, at pH 12.5, partial conversion into strand breaks occurred after 30 min. At pH> 13, the hairpins were almost completely degraded after 30 min. The flash protocol effectively detects DNA single- and double-strand breaks and identified these damages after 2.5 min of alkaline treatment at pH 12.5. When the hairpins were exposed to pH 12.5 for 60 min, ALS were converted to strand breaks, demonstrating the sensitivity of this approach to detect changes in DNA structure. These findings indicate that pH poses a substantial risk to DNA integrity, leading to significantly higher background levels of DNA damage compared to conditions closer to neutrality. Our study demonstrates the importance of understanding the influence of pH on DNA stability and provides insights into risks associated with alkaline environments, especially at pH> 13.</p></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41136077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}