As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative International Validation Study of an in vivo rat alkaline comet assay, we examined 1,2-dibromoethane (DBE), p-anisidine (ASD), and o-anthranilic acid (ANT) to investigate the effectiveness of the comet assay in detecting genotoxic carcinogens. Each of the three test chemicals was administered to 5 male Sprague-Dawley rats per group by oral gavage at 48, 24, and 3h before specimen preparation. Single cells were collected from the liver and glandular stomach at 3h after the final dosing, and the specimens prepared from these two organs were subjected to electrophoresis under alkaline conditions (pH>13). The percentage of DNA intensity in the comet tail was then assessed using an image analysis system. A micronucleus (MN) assay was also conducted using these three test chemicals with the bone marrow (BM) cells collected from the same animals simultaneously used in the comet assay, i.e., combination study of the comet assay and BM MN assay. A genotoxic (Ames positive) rodent carcinogen, DBE gave a positive result in the comet assay in the present study, while a genotoxic (Ames positive) non-carcinogen, ASD and a non-genotoxic (Ames negative) non-carcinogen, ANT showed negative results in the comet assay. All three chemicals produced negative results in the BM MN assay. While the comet assay findings in the present study were consistent with those obtained from the rodent carcinogenicity studies for the three test chemicals, we consider the positive result in the comet assay for DBE to be particularly meaningful, given that this chemical produced a negative result in the BM MN assay. Therefore, the combination study of the comet assay and BM MN assay is a useful method to detect genotoxic carcinogens that are undetectable with the BM MN assay alone.
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http://dx.doi.org/10.1016/j.mrgentox.2015.03.002 | DOI Listing |
Toxins (Basel)
December 2024
Division of Toxicology, Institute for Medical Research and Occupational Health, HR-10 000 Zagreb, Croatia.
The increasing use of products for medicinal, dietary, and recreational purposes has raised concerns about mycotoxin contamination in cannabis and hemp. Mycotoxins persist in these products' post-processing, posing health risks via multiple exposure routes. This study investigated cytotoxic and genotoxic interactions between cannabidiol (CBD) and the mycotoxin citrinin (CIT) using human cell models: SH-SY5Y, HepG2, HEK293, and peripheral blood lymphocytes.
View Article and Find Full Text PDFEnviron Mol Mutagen
December 2024
GENOTOX Laboratory, São Paulo State University (UNESP), Medical School, Botucatu, Brazil.
Sevoflurane is an inhalation anesthetic widely used for general anesthesia, but its genotoxic potential is controversial in clinical studies. It is unknown whether the effects are due to surgery or the anesthetic. Thus, for the first time, the present study investigated genotoxicity in peripheral blood cells and in target organs (liver, lung, and kidney) and micronucleus (MN) in the bone marrow of a single exposure to sevoflurane at three different concentrations in monitored mice.
View Article and Find Full Text PDFPart Fibre Toxicol
December 2024
Health Effects Laboratory, Department of Environmental Chemistry and Health Effects, NILU, 2007, Kjeller, Norway.
Background: Hazard and risk assessment of nanomaterials (NMs) face challenges due to, among others, the numerous existing nanoforms, discordant data and conflicting results found in the literature, and specific challenges in the application of strategies such as grouping and read-across, emphasizing the need for New Approach Methodologies (NAMs) to support Next Generation Risk Assessment (NGRA). Here these challenges are addressed in a study that couples physico-chemical characterization with in vitro investigations and in silico similarity analyses for nine nanoforms, having different chemical composition, sizes, aggregation states and shapes. For cytotoxicity assessment, three methods (Alamar Blue, Colony Forming Efficiency, and Electric Cell-Substrate Impedance Sensing) are applied in a cross-validation approach to support NAMs implementation into NGRA.
View Article and Find Full Text PDFProbl Radiac Med Radiobiol
December 2024
State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Yuriia Illienka Str., Kyiv, 04050, Ukraine.
Objective: to investigate the reciprocal impact on the genome of malignant and normal human peripheral bloodlymphocytes under their co-culture and the possibility to modify the effects by astaxanthin.
Methods: Separate and joint/separate culturing of peripheral blood lymphocytes (PBL) of the chronic lymphocyticleukemia (CLL) patients (n = 6) and conditionally healthy individuals (n = 6), Comet assay method, fluorescencemicroscopy with automated software for the analysis of results, statistical methods.
Results: Both direct and rescue tumour-induced bystander effects were observed under the joint/separate culturing of blood lymphocytes of conditionally healthy individuals (the bystander cells) and blood cells from CLL patients(the inducer cells).
Probl Radiac Med Radiobiol
December 2024
Educational and Scientific Center «Institute of Biology and Medicine» of the Taras Shevchenko Kyiv National University, 64/13 Volodymyrska Str., Kyiv, 01601, Ukraine.
Objective: to investigate changes in DNA methylation in bystander and inducer cells during the manifestation ofdirect and rescue bystander effects.
Methods: Separate and co-cultivation of peripheral blood lymphocytes (PBL) of 10 conditionally healthy individuals; γ-quantum irradiation (IBL-237C emitter); modified comet electrophoresis method (Comet assay) under neutralconditions using the methylation-sensitive restriction enzyme HpaII; fluorescence microscopy with an automatedcomputer software system for analyzing the results; statistical methods.
Results: The level of DNA methylation in PBL was quantitatively assessed using DNA migration parameters inagarose gel: the length of the comet tail (in μm), the percentage of DNA in the tail part of the comet, and TailMoment (TM), which simultaneously takes into account both the amount of DNA in the tail part of the comet andthe length of the tail.
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