Evaluation of the liver and blood micronucleus, and comet assay end points in a 14-day repeated-dose study with methyl carbamate and 1,3-propane sultone

Mutagenesis ◽  
2021 ◽  
Author(s):  
Honggang Tu ◽  
Chunrong Yu ◽  
Wen Tong ◽  
Changhui Zhou ◽  
Ruowan Li ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Comprehensive Evaluation ◽  
Micronucleus Assay ◽  
Negative Control ◽  
Repeated Dose ◽  
End Points ◽  
Dose Study ◽  
Novel Method ◽  
Genotoxic Chemicals

Abstract The repeated-dose liver micronucleus (RDLMN) assay is a novel method for detecting genotoxic chemicals. Two carcinogens methyl carbamate (MC) and 1,3-propane sultone (PS) were evaluated for the liver micronucleus in a 14-day repeated-dose study with Crl: CD (SD) IGS rats. Additionally, micronucleated reticulocytes (MN-RET) in peripheral blood and DNA damage (alkaline comet assay) in the liver were also assessed in the same animals. Ten groups of five male Crl: CD (SD) IGS rats were treated once daily with MC (300, 600 or 1200 mg/kg/day), PS (37.5, 75 or 150 mg/kg/day), negative control or three positive controls by oral gavage for 15 days. Blood samples were collected at 3 h after the last administration for determining MN-RET frequencies (%MN-RET), and the livers were sampled for determining the frequency of micronuclei and DNA damage. MC was negative in the comet assay, liver micronucleus assay and reticulocyte micronucleus assay, while PS was positive in all three assays. These results are consistent with the previous genotoxic findings of MC and PS. Therefore, the liver micronucleus assay can be effectively integrated into repeated-dose studies in animals. Moreover, integration of multiple genotoxicity end points into one study can reduce the number of animals, boost the experimental efficiency, and provides a comprehensive evaluation of the genotoxic potential of chemicals.

scholarly journals Effects of photopolymerisation on genotoxicity of composite adhesives in the comet assay

Genetika ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 617-627
Author(s):  
Stefan Dacic ◽  
Ninoslav Djelic ◽  
Milena Radakovic ◽  
Nada Lakic ◽  
Aleksandar Veselinovic ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Human Lymphocytes ◽  
Negative Control ◽  
In Vivo Studies ◽  
Halogen Lamp ◽  
Genotoxic Effects ◽  
Significant Difference ◽  
Isolated Human Lymphocytes

Certain in vivo studies have shown that the application of adhesives directly onto the open pulp or on a thin layer of dentin causes inflammation and pulpal abscesses. This reaction is related to toxic effects of monomers from adhesives. It has been confirmed that after proper illumination the adhesives become less toxic. The aim of the study was to examine genotoxicity of non-polymerised, partly polymerised and polymerised adhesives on isolated human lymphocytes using the alkaline Comet assay. Adper Single bond2 and Adper Easy One/3M ESPE adhesive photopolymerisation was performed by Elipar Highlight 3M ESPE halogen lamp for 0, 10 and 40 sec, at final concentrations of 100, 200, 500 and 1000 ?g/mL. With both adhesives, photopolymerisation at 0 and 10 seconds showed statistically significant increase in DNA damage in comparision to the negative control (solvent). On the other hand, after 40 seconds of photopolymerisation of both adhesives in all tested concentrations, the degree of DNA damage in Comet assay had no significant difference (P>0.05, ?2 test) compared to the negative control. Therefore, only the 40 seconds of photopolymerisation prevented genotoxic effects of both adhesives in the Comet assay.

scholarly journals Genotoxicity and Cytotoxicity of Gold Nanoparticles In Vitro: Role of Surface Functionalization and Particle Size

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 271 ◽  
Author(s):  
Gerard Vales ◽  
Satu Suhonen ◽  
Kirsi M. Siivola ◽  
Kai M. Savolainen ◽  
Julia Catalán ◽  
...  
Keyword(s):  
Dna Damage ◽  
Gold Nanoparticles ◽  
Comet Assay ◽  
Positive Result ◽  
Cellular Uptake ◽  
Micronucleus Assay ◽  
Gold Nps ◽  
20 Nm

Several studies suggested that gold nanoparticles (NPs) could be genotoxic in vitro and in vivo. However, gold NPs have currently produced present a wide range of sizes and functionalization, which could affect their interactions with the environment or with biological structures and, thus, modify their toxic effects. In this study, we investigated the role of surface charge in determining the genotoxic potential of gold NPs, as measured by the induction of DNA damage (comet assay) and chromosomal damage (micronucleus assay) in human bronchial epithelial BEAS-2B cells. The cellular uptake of gold NPs was assessed by hyperspectral imaging. Two core sizes (~5 nm and ~20 nm) and three functionalizations representing negative (carboxylate), positive (ammonium), and neutral (poly(ethylene glycol); (PEG)ylated) surface charges were examined. Cationic ammonium gold NPs were clearly more cytotoxic than their anionic and neutral counterparts, but genotoxicity was not simply dependent on functionalization or size, since DNA damage was induced by 20-nm ammonium and PEGylated gold NPs, while micronucleus induction was increased by 5-nm ammonium and 20-nm PEGylated gold NPs. The 5-nm carboxylated gold NPs were not genotoxic, and evidence on the genotoxicity of the 20-nm carboxylated gold NPs was restricted to a positive result at the lowest dose in the micronucleus assay. When interpreting the results, it has to be taken into account that cytotoxicity limited the doses available for the ammonium-functionalized gold NPs and that gold NPs have earlier been described to interfere with the comet assay procedure, possibly resulting in a false positive result. In conclusion, our findings show that the cellular uptake and cytotoxicity of gold NPs are clearly enhanced by positive surface charge, but neither functionalization nor size can single-handedly account for the genotoxic effects of the gold NPs.

Fructose consumption during pregnancy and lactation causes DNA damage and biochemical changes in female mice

Mutagenesis ◽  
2020 ◽  
Vol 35 (2) ◽  
pp. 179-187
Author(s):  
Marina Lummertz Magenis ◽  
Adriani Paganini Damiani ◽  
Pamela Souza de Marcos ◽  
Ellen de Pieri ◽  
Emanuel de Souza ◽  
...  
Keyword(s):  
Dna Damage ◽  
Body Weight ◽  
Comet Assay ◽  
Negative Control ◽  
Lactation Period ◽  
Swiss Mice ◽  
Pregnancy And Lactation ◽  
Consumption Energy ◽  
Fasting Glycaemia ◽  
Control Water

Abstract The consumption of fructose during pregnancy can cause hyperglycaemia and may stimulate production of reactive oxygen species; however, there are only a few studies reporting whether fructose consumption during pregnancy causes DNA damage. Therefore, the aim of this study was to evaluate the effects of fructose consumption on genetic and biochemical parameters in Swiss mice treated during pregnancy and lactation. For this, 15 couples of 60-day-old Swiss mice were divided into three groups of five couples: negative control (water) and two fructose groups (fructose dose of 10%/l and 20%/l). During this period, we evaluated food consumption, energy efficiency and body weight. Samples of blood were collected from the females before copulation, after the 15th day of conception and on the 21st day after the lactation period, for the glycaemic and lipid profiles as well as comet assay and micronucleus (MN) test. Comet assay and MN test evaluate DNA damage and clastogenicity, respectively. In the gestation and lactation period, the two fructose doses tested showed DNA damage as observed in the comet assay, which is associated with an increase in dietary intake, body weight, lipid profile and fasting glycaemia in females. Thus, it can be suggested that the high consumption of fructose during these periods is harmful for pregnancy and lactation.

Quantification of DNA damage in patients undergoing non-contrast and contrast enhanced whole body PET/CT investigations using comet assay and micronucleus assay

2019 ◽  
Vol 95 (6) ◽  
pp. 710-719 ◽  
Author(s):  
Amit Nautiyal ◽  
Tanmoy Mondal ◽  
Anirban Mukherjee ◽  
Deepanjan Mitra ◽  
Aruna Kaushik ◽  
...  
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Micronucleus Assay ◽  
Whole Body ◽  
Contrast Enhanced ◽  
Pet Ct

COMPARISON OF TWO BIOMODELS (BALB/C MICE AND SPRAGUE DAWLEY RATS) IN THE ALKALINE COMET ASSAY

2020 ◽  
Vol 4 (13-16) ◽  
Author(s):  
Daniel Francisco Arencibia Arrebola ◽  
Luis Alfredo Rosario Fernández ◽  
Yolanda Emilia Suárez Fernández ◽  
Alexis Vidal Novoa
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Peripheral Blood ◽  
Species Group ◽  
Negative Control ◽  
Control Group ◽  
Alkaline Comet Assay ◽  
Sprague Dawley ◽  
Sd Rats ◽  
Sprague Dawley Rats

<p>This article had as objective to carry out a comparison between Balb/c mice and Sprague Dawley rats as biomodel in the alkaline comet assay, keeping in mind the basal frequency and that induced with Cyclophosphamide, the induction of single strand breaks (SSB) or alkali-labile sites formation on DNA of peripheral blood leukocytes. Ten animal/sex/species/group of Balb/c mice and Sprague Dawley rats were used, and treated for 14 days. Using a negative control group (not treated), two substance-vehicle controls and a positive control received cyclophosphamide 50 mg/kg, via intraperitoneal. After two weeks the alkaline electrophoresis gel was performed for individual cells from leukocytes of peripheral blood to screen for possible DNA damage. The best biomodel in both sexes was the SD rats differing significantly with the results obtained in Balb/c mice keeping in mind the spontaneous and induced values of DNA damage. This study shows SD rats are a more efficient model for preclinical genotoxic evaluation of drugs, vaccines and natural products.</p>

scholarly journals Adaptation of the in vitro micronucleus assay for genotoxicity testing using 3D liver models supporting longer-term exposure durations

Mutagenesis ◽  
2020 ◽  
Vol 35 (4) ◽  
pp. 319-330 ◽  
Author(s):  
Gillian E Conway ◽  
Ume-Kulsoom Shah ◽  
Samantha Llewellyn ◽  
Tereza Cervena ◽  
Stephen J Evans ◽  
...  
Keyword(s):  
Dna Damage ◽  
3D Model ◽  
Low Dose ◽  
Micronucleus Assay ◽  
3D Models ◽  
Short Term ◽  
Cell Cycles ◽  
Genotoxic Chemicals ◽  
In Vitro Micronucleus Assay

Abstract Following advancements in the field of genotoxicology, it has become widely accepted that 3D models are not only more physiologically relevant but also have the capacity to elucidate more complex biological processes that standard 2D monocultures are unable to. Whilst 3D liver models have been developed to evaluate the short-term genotoxicity of chemicals, the aim of this study was to develop a 3D model that could be used with the regulatory accepted in vitro micronucleus (MN) following low-dose, longer-term (5 days) exposure to engineered nanomaterials (ENMs). A comparison study was carried out between advanced models generated from two commonly used liver cell lines, namely HepaRG and HepG2, in spheroid format. While both spheroid systems displayed good liver functionality and viability over 14 days, the HepaRG spheroids lacked the capacity to actively proliferate and, therefore, were considered unsuitable for use with the MN assay. This study further demonstrated the efficacy of the in vitro 3D HepG2 model to be used for short-term (24 h) exposures to genotoxic chemicals, aflatoxin B1 (AFB1) and methyl-methanesulfonate (MMS). The 3D HepG2 liver spheroids were shown to be more sensitive to DNA damage induced by AFB1 and MMS when compared to the HepG2 2D monoculture. This 3D model was further developed to allow for longer-term (5 day) ENM exposure. Four days after seeding, HepG2 spheroids were exposed to Zinc Oxide ENM (0–2 µg/ml) for 5 days and assessed using both the cytokinesis-block MN (CBMN) version of the MN assay and the mononuclear MN assay. Following a 5-day exposure, differences in MN frequency were observed between the CBMN and mononuclear MN assay, demonstrating that DNA damage induced within the first few cell cycles is distributed across the mononucleated cell population. Together, this study demonstrates the necessity to adapt the MN assay accordingly, to allow for the accurate assessment of genotoxicity following longer-term, low-dose ENM exposure.

DNA and oxidative damage induced in somatic organs and tissues of mouse by municipal sludge leachate

2011 ◽  
Vol 28 (7) ◽  
pp. 614-623 ◽  
Author(s):  
Adekunle A Bakare ◽  
Sushila Patel ◽  
Alok K Pandey ◽  
Mahima Bajpayee ◽  
Alok Dhawan
Keyword(s):  
Bone Marrow ◽  
Dna Damage ◽  
Comet Assay ◽  
Health Effects ◽  
Negative Control ◽  
Human Populations ◽  
Municipal Sludge ◽  
Potential Health ◽  
Adverse Health Effects ◽  
Somatic Tissues

Pollution by waste landfill leachate has prompted a number of studies on the toxic and potential health effects. This study assessed the genotoxicity of a municipal sludge leachate (MSL) in the somatic tissues (blood and bone marrow) and organs (liver, kidney, and spleen) of mice using the alkaline Comet assay. The possible cause of DNA damage via the study of antioxidant system (lipid peroxidation [LPO]; catalase [CAT]; reduced glutathione [GSH]; and superoxide dismutase [SOD]) responses in mouse liver was also investigated. Different concentrations (2.5%, 5%, 10%, and 15%) of the leachate were administered intraperitoneally for 5 consecutive days to male Swiss albino mice (4 mice/group). A significant ( p < 0.05) increase in DNA damage in organs and tissues of treated mice compared to the negative control was observed as evident from the Comet assay parameters: olive tail moment (OTM, arbitrary units) and tail DNA (%). Bone marrow showed maximum DNA damage followed by liver > spleen > kidney > blood as evident by the OTM. A significant increase ( p < 0.05) in the level of antioxidant enzymes (CAT and SOD) and LPO with a concurrent decrease in GSH in the liver of treated mice was also observed. Our finding demonstrates that the MSL induces DNA damage in the somatic tissues and organs of mouse as well as induces oxidative stress in the liver. These tissues and organs may be the potential targets in animal and human populations exposed to MSL. This is of relevance to public health; as such exposure could lead to adverse health effects via systemic genotoxicity.

Radiation-induced versus endogenous DNA damage and assays that measure parameters reflecting DNA damage on cell by cell basis: comments on the article by Pollycove and Feinendegen

2003 ◽  
Vol 22 (6) ◽  
pp. 309-313 ◽  
Author(s):  
Joseph L Roti Roti
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Micronucleus Assay ◽  
State Level ◽  
Dna Lesions ◽  
Cell Basis ◽  
Significant Difference ◽  
Dependent Parameter ◽  
A Cell ◽  
Radiation Induced

The article by Pollycove and Feinendegen raises important issues regarding the relative contributions of endogenous and radiation-induced DNA damage to the overall DNA damage burden following low level radiation exposures. Clearly, resolution of the issues raised in their article will have important implications regarding regulatory philosophy. Dose-limiting studies of DNA damage measured on a cell-by-cell basis was used to analyze available data in the context of the proposed model. If one proposes that significant numbers of oxidative DNA lesions are present in cells at a steady state level at any give time, then such damage will be included in the background measure of any DNA damage dependent parameter that is sensitive to these classes of DNA damage. Then the expected number of lesions per cell was compared, prior to X- or γ-ray exposure, at the dose that gives the minimum statistically significant difference from background, at the dose where the DNA damage dependent parameter is twice background (i.e., the doubling dose). The lesion frequencies predicted from the model by Pollycove and Feinendegen are reasonable for the micronucleus assay and the inhibition of DNA supercoil rewinding, but appear to be inconsistent with results from the comet assay. Possible explanations for the inconsistency between the comet assay dose) response data and the predicted levels of DNA damage predicted by the model are discussed, suggesting that the estimates of the radiation induced damage are too low and those for endogenous damage are too high. The goal in introducing these issues is not to be negative to the article but to present a basis for future discussions and more importantly future experimental work, by which the important issues raised can be resolved.

Sign in / Sign up

Export Citation Format

Share Document