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If a new drug candidate will be a mixture of enantiomers, both enantiomers should be separately studied for at least latent genotoxicity as early as possible since the thalidomide tragedy. Our group has recently reported that KCP-10043F (OZ-001) as a racemate (±)-3,4-dihydroquinazoline derivative strongly represses the proliferation of human A549 lung cancer cells by caspase-mediated apoptosis via STAT3 inactivation. To investigate the possible teratological effects of the two enantiomers of a racemic KCP-10043F, therefore chiral resolution of (±)-KCP-10043F was performed and subsequently followed by a series of chemical processes to afford the corresponding chiral diastereomers. By using 1H NMR anisotropy method, the absolute configuration (+)-KCP-10043F and (−)-KCP-10043F could be assigned as S and R configuration, respectively. The bacterial reverse mutation test (Ames test) for racemate (±)-KCP-10043F and its two enantiomers exhibited that all three stereoisomers were found to be nongenotoxic against five bacterial strains with/without metabolic activation. In addition, (R)-(−)-KCP-10043F displayed almost equal anticancer activity to (S)-(+)-KCP-10043F against three cancer cell lines. Based on these overall results, racemate KCP-10043F (OZ-001) could be used for our ongoing preclinical and clinical studies without the expensive asymmetric process and/or chiral separation.

Nanotechnology-based drugs show superiority over conventional medicines because of increased bioavailability, lower accumulation in non-target tissues, and improved therapeutic index with increased accumulation at target sites. However, it is important to be aware of possible problems related to the toxicity of these products, which have therapeutically superior properties. Accordingly, the present study was designed to investigate the safety profile of amoxicillin nanoparticles (AmxNPs) that we developed to increase the oral bioavailability of amoxicillin (Amx) in poultry. In the first part of the study, the genotoxicity potential of AmxNPs was evaluated using the Ames test and the in vitro comet assay. The results of Ames test showed that none of the tested concentrations of Amx and AmxNPs cause a significant increase in the revertant number of Salmonella typhimurium strains TA98, and TA100, either with or without metabolic activation. Similarly, the comet assay revealed that AmxNPs did not induce DNA damage at any of the concentrations used, whereas high-dose (200 μg/mL) of Amx caused a significant increase in the percentage of DNA in the tail. In the second part of the study, the toxicity potential of AmxNPs on broilers was investigated by measuring biochemical parameters. In vivo results demonstrated that AmxNps did not cause a significant change in biochemical parameters, whereas Amx increased ALT, glucose, and cholesterol levels at certain sampling times. The obtained findings suggest that AmxNPs could be a safe promising potential drug in drug delivery systems.

The main bactericidal components of cold atmospheric plasma (CAP) are thought to be reactive oxygen and nitrogen species (RONS) and UV-radiation, both of which have the capacity to cause DNA damage and mutations. Here, the mutagenic effects of CAP on Escherichia coli were assessed in comparison to X- and UV-irradiation. DNA damage and mutagenesis were screened for using a diffusion-based DNA fragmentation assay and modified Ames test, respectively. Mutant colonies obtained from the latter were quantitated and sequenced. CAP was found to elicit a similar mutation spectrum to X-irradiation, which did not resemble that for UV implying that CAP-produced RONS are more likely the mutagenic component of CAP. CAP treatment was also shown to promote resistance to the antibiotic ciprofloxacin. Our data suggest that CAP treatment has mutagenic effects that may have important phenotypic consequences.

In the present study, the antimicrobial and antibiofilm activities of two 4,5-dihydro-1H-pyrazole-1-carboximidamide hydrochloride, (trifluoromethyl) phenyl-substituted (compound 1) and bromophenyl-substituted (compound 2), were evaluated against four Salmonella spp. serotypes through broth microdilution and biofilm-forming activity. Further, the cytotoxicity of the compounds was evaluated by cell viability assays using cultures of HeLa and Vero cell lines, and the mutagenic potential was assessed by the Ames test. In the broth microdilution test, compound 1 inhibited 90% of the strains tested at the minimum inhibitory concentration of 62.5 μg mL−1. Furthermore, both compounds prevented biofilm formation, with a reduction of up to 5.2 log10. HeLa and Vero cells exhibited 100% viability in the presence of compound 1. In contrast, low cell viability was observed in the presence of 15 µg mL−1 of compound 2. Furthermore, no mutagenic potential was detected at any of the tested concentrations of compound 1.

Environmental mutagens are chemical and physical substances in the environment that has a potential to induce a wide range of mutations and generate multiple physiological, biochemical, and genetic modifications in humans. Most mutagens are having genotoxic effects on the following generation through germ cells. The influence of germinal mutations on health will be determined by their frequency, nature, and the mechanisms that keep a specific mutation in the population. Early prenatal lethal mutations have less public health consequences than genetic illnesses linked with long-term medical and social difficulties. Physical and chemical mutagens are common mutagens found in the environment. These two environmental mutagens have been associated with multiple neurological disorders and carcinogenesis in humans. Thus in this study, we aim to unravel the molecular mechanism of physical mutagens (UV rays, X-rays, gamma rays), chemical mutagens (dimethyl sulfate (DMS), bisphenol A (BPA), polycyclic aromatic hydrocarbons (PAHs), 5-chlorocytosine (5ClC)), and several heavy metals (Ar, Pb, Al, Hg, Cd, Cr) implicated in DNA damage, carcinogenesis, chromosomal abnormalities, and oxidative stress which leads to multiple disorders and impacting human health. Biological tests for mutagen detection are crucial; therefore, we also discuss several approaches (Ames test and Mutatox test) to estimate mutagenic factors in the environment. The potential risks of environmental mutagens impacting humans require a deeper basic knowledge of human genetics as well as ongoing research on humans, animals, and their tissues and fluids.

Genotoxicity testing plays an important role in the safety assessment of pharmaceuticals, pesticides and chemical substances. Among the guidelines for various genotoxicity tests, the in vitro genotoxicity test battery comprises the bacterial Ames test and mammalian cell assays. Several chemicals exhibit conflicting results for the bacterial Ames test and mammalian cell genotoxicity studies, which may stem from the differences in DNA repair capacity or metabolism, between different cell types or species. For better understanding the mechanistic implications regarding conflict outcomes between different assay systems, it is necessary to develop in vitro genotoxicity testing approaches with higher specificity towards DNA-damaging reagents. We have recently established an improved thymidine kinase (TK) gene mutation assay (TK assay) i.e. deficient in DNA excision repair system using human lymphoblastoid TK6 cells lacking XRCC1 and XPA (XRCC1−/−/XPA−/−), the core factors of base excision repair (BER) and nucleotide excision repair (NER), respectively. This DNA repair-deficient TK6 cell line is expected to specifically evaluate the genotoxic potential of chemical substances based on the DNA damage. We focussed on four reagents, N-(1-naphthyl)ethylenediamine dihydrochloride (NEDA), p-phenylenediamine (PPD), auramine and malachite green (MG) as the Ames test-positive chemicals. In our assay, assessment using XRCC1−/−/XPA−/− cells revealed no statistically significant increase in the mutant frequencies after treatment with NEDA, PPD and MG, suggesting the chemicals to be non-genotoxic in humans. The observations were consistent with that of the follow-up in vivo studies. In contrast, the mutant frequency was markedly increased in XRCC1−/−/XPA−/− cells after treatment with auramine. The results suggest that auramine is the genotoxic reagent that preferentially induces DNA damages resolved by BER and/or NER in mammals. Taken together, BER/NER-deficient cell-based genotoxicity testing will contribute to elucidate the mechanism of genotoxicity and therefore play a pivotal role in the accurate safety assessment of chemical substances.

The objective of the study: evaluation of mutagenic properties of thiosonide in tests of chromosomal aberrations in mammalian bone marrow cells and mutation accounting on Salmonella typhimurium strains.Subjects and methods. Studies were carried out using F1 hybrids of CBA×C57BL/6 mice, they received thiozonide in the equivalent of a therapeutic dose and 160 times above it, once and in the course of 5 injections. The genetic toxicity of thiosonide was evaluated on Salmonella typhimurium strains in the tested doses of 1,000, 100, 10, 1 and 0.1 μg per plate.Results. No mutagenic activity of thiosonide in the chromosomal aberration counting test in bone marrow cells of mice was demonstrated. The level of chromosome aberrations in the experiment did not exceed the corresponding control values. Thus, thiosonide at the therapeutic dose (25 mg/kg) and 160-fold increase above it (4,000 mg/kg) did not induce chromosomal aberrations in the bone marrow cells of mice either with single dosing or several intragastric administrations.According to the Ames test results, the number of revertant colonies in the solvent control in the CM- and CM+ variants was within the range of spontaneous fluctuations for these strains; thiosonide in all tested doses did not show mutagenic effect on the TA 100, TA 98, and TA 97 strains both with the system metabolic activation and without it.

Nicotiana tabacum is the most cultivated tobacco species in the state of Rio Grande do Sul, Brazil. Workers who handle the plant are exposed to the leaf components during the harvesting process and when separating and classifying the dried leaves. In addition to nicotine, after the drying process, other components may be found including tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, as well as pesticides residues. The objective of this study was to examine the genotoxicity attributed to the aqueous extract of dried tobacco leaves obtained from tobacco barns using Chinese hamster lung fibroblast cells (V79) as a model system by employing alkaline comet assay, micronucleus (MN) and Ames test. MTT assay was used to assess cytotoxicity and establish concentrations for this study. Data demonstrated cell viability > 85% for concentrations of 0.625-5 mg/ml while the comet assay indicated a significant increase in DNA damage at all concentrations tested. A significant elevation of MN and nuclear buds (NBUD) was found for 5 mg/ml compared to control and other dry tobacco leaves concentrations (0.625-2.5 mg/ml). Mutagenicity was not found using the Salmonella/Microsome test (TA98, TA100, and TA102 strains) with and without metabolic activation. The concentration of inorganic elements was determined employing the PIXE technique, and 13 inorganic elements were detected. Using CG/MS nicotine amounts present were 1.56 mg/g dry tobacco leaf powder. Due to the observed genotoxicity in V79 cells, more investigations are needed to protect the health of tobacco workers exposed daily to this complex mixture of toxic substances present in dry tobacco leaves.

Background Conflicting results between bacterial mutagenicity tests (the Ames test) and mammalian carcinogenicity tests might be due to species differences in metabolism, genome structure, and DNA repair systems. Mutagenicity assays using human cells are thought to be an advantage as follow-up studies for positive results in Ames tests. In this collaborative study, a thymidine kinase gene mutation study (TK6 assay) using human lymphoblastoid TK6 cells, established in OECD TG490, was used to examine 10 chemicals that have conflicting results in mutagenicity studies (a positive Ames test and a negative result in rodent carcinogenicity studies). Results Two of 10 test substances were negative in the overall judgment (20% effective as a follow-up test). Three of these eight positive substances were negative after the short-term treatment and positive after the 24 h treatment, despite identical treatment conditions without S9. A toxicoproteomic analysis of TK6 cells treated with 4-nitroanthranilic acid was thus used to aid the interpretation of the test results. This analysis using differentially expressed proteins after the 24 h treatment indicated that in vitro specific oxidative stress is involved in false positive response in the TK6 assay. Conclusions The usefulness of the TK6 assay, by current methods that have not been combined with new technologies such as proteomics, was found to be limited as a follow-up test, although it still may help to reduce some false positive results (20%) in Ames tests. Thus, the combination analysis with toxicoproteomics may be useful for interpreting false positive results raised by 24 h specific reactions in the assay, resulting in the more reduction (> 20%) of false positives in Ames test.

A precise understanding of differences in genomic mutations according to the mutagenic mechanisms detected in mutagenicity data is required to evaluate the carcinogenicity of environmental mutagens. Recently, we developed a highly accurate genome sequencing method, ‘Hawk-Seq™’, that enables the detection of mutagen-induced genome-wide mutations. However, its applicability to detect various mutagens and identify differences in mutational profiles is not well understood. Thus, we evaluated DNA samples from Salmonella typhimurium TA100 exposed to 11 mutagens, including alkylating agents, aldehydes, an aromatic nitro compound, epoxides, aromatic amines and polycyclic aromatic hydrocarbons (PAHs). We extensively analysed mutagen-induced mutational profiles and studied their association with the mechanisms of mutagens. Hawk-Seq™ sensitively detected mutations induced by all 11 mutagens, including one that increased the number of revertants by approximately 2-fold in the Ames test. Although the sensitivity for less water-soluble mutagens was relatively low, we increased the sensitivity to obtain high-resolution spectra by modifying the exposure protocol. Moreover, two epoxides indicated similar 6- or 96-dimensional mutational patterns; likewise, three SN1-type alkylating agents indicated similar mutational patterns, suggesting that the mutational patterns are compound category specific. Meanwhile, an SN2 type alkylating agent exhibited unique mutational patterns compared to those of the SN1 type alkylating agents. Although the mutational patterns induced by aldehydes, the aromatic nitro compound, aromatic amines and PAHs did not differ substantially from each other, the maximum total base substitution frequencies (MTSFs) were similar among mutagens in the same structural groups. Furthermore, the MTSF was found to be associated with the carcinogenic potency of some direct-acting mutagens. These results indicate that our method can generate high-resolution mutational profiles to identify characteristic features of each mutagen. The detailed mutational data obtained by Hawk-Seq™ can provide useful information regarding mutagenic mechanisms and help identify its association with the carcinogenicity of mutagens without requiring carcinogenicity data.

Background Chikungunya fever is an endemic disease caused by the Chikungunya virus (CHIKV) to which there is no vaccine or effective antiviral drug treatment so far. Our study aimed to evaluate the potential anti-CHIKV activity of memantine hydrochloride (mtnH), a drug from the class of the aminoadamantanes approved for the treatment of Alzheimer´s disease, as a possible drug to be repurposed to the treatment of Chikungunya fever. Methods MtnH antiviral activity against CHIKV was determined by infecting BHK-21 cells with CHIKV-nanoluc, a virus carrying the marker nanoluciferase reporter, in the presence or absence of mtnH at concentrations ranging from 500 to 1.45 µM. The effective concentration of 50% inhibition (EC50) was calculated. Cell viability assay (determination of CC50) was also performed employing BHK-21 cells. Mutagenic assays were performed by the Salmonella Typhimurium/microsome assay (Ames test). Results MtnH presented a CC50 of 248.4 ± 31.9 µM and an EC50 of 32.4 ± 4 µM against CHIKV in vitro. The calculated selectivity index (SI) was 7.67. MtnH did not induce genetic mutation in Salmonella strains with or without an external metabolizing system. Conclusion With the data herein presented, it is possible to hypothesize mtnH as a viable candidate to be repurposed as an anti-CHIKV drug. Clinical assays are, therefore, encouraged due to the promising in vitro results. Graphic abstract The drug memantine hydrochloride is herein personified with a doubt: as a prior regulated drug against Alzheimer, could it follow the path against Chikungunya virus too?

The presented study aims to extend the knowledge of toxicological profile of rare earth elements salts (REEs). The basal toxicity test performed comprised assessment of cytotoxicity (3T3 Balb/c Neutral Red Uptake Test) that allows for calculation of LD50 (rats) on the basis of the concentration which leads to a 50% reduction in cell growth (IC50). Environmental toxicity was addressed by the Tubifex tubifex (T.t.) express test. The in vitro skin irritation (OECD TG 439) and skin corrosion tests (OECD TG 431) utilizing the 3D in vitro reconstructed human epidermal model EpiDerm (MatTek IVSL, SK) were used for assessment of skin irritation and corrosion potential hazard of REEs. Mutagenic effects were determined using the bacterial reverse mutation assay (Ames Test) on 5 Salmonella typhimurium strains with and without metabolic activation (OECD TG 471). Endocrine disruption was evaluated by means of a yeast-based assay YES/YAS (Xenometrix, CH). Skin sensitization was assessed using the LuSens assay, based on a genetically modified human keratinocyte cell line (OECD TG 442D). The tested REEs have no potential of mutagenicity or skin sensitization, exhibit very weak endocrine disruption potential and only exceptional local irritation/corrosion effects for thulium (III) chloride anhydrous, but have acute and chronic toxic effects on the aquatic environment.

Made available in DSpace on 2021-06-25T10:50:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Myrcia bella is a medicinal plant used for the treatment of diabetes, hemorrhages, and hypertension in Brazilian folk medicine. Considering that plant extracts are attractive sources of new drugs, the aim of the present study was to verify the influence of incorporating 70% hydroalcoholic of M. bella leaves in nanostructured lipid systems on the mutagenic and antifungal activities of the extract. In this work, we evaluated the antifungal potential of M. bella loaded on the microemulsion against Candida sp for minimum inhibitory concentration, using the microdilution technique. The system was composed of polyoxyethylene 20 cetyl ether and soybean phosphatidylcholine (10%), grape seed oil, cholesterol (10%: proportion 5/1), and purified water (80%). To investigate the mutagenic activity, the Ames test was used with the Salmonella Typhimurium tester strains. M. bella, either incorporated or free, showed an important antifungal effect against all tested strains. Moreover, the incorporation surprisingly inhibited the mutagenicity presented by the extract. The present study attests the antimicrobial properties of M. bella extract, contributing to the search for new natural products with biological activities and suggesting caution in its use for medicinal purposes. In addition, the results emphasize the importance of the use of nanotechnology associated with natural products as a strategy for the control of infections caused mainly by the genus Candida sp. University of Araraquara (UNIARA) Department of Biological Sciences and Health São Paulo State University (UNESP) Department of Biological Sciences Faculty of Science São Paulo State University (UNESP) Department of Biological Sciences School of Pharmaceutical Sciences, Campus Araraquara São Paulo State University (UNESP) Department of Drugs and Medicines School of Pharmaceutical Sciences, Campus Araraquara University of Brasilia Nanobiotechnology Laboratory Department of Genetics and Morphology University of Araraquara Department of Biological Sciences and Health UNIARA Carlos Gomes 1338, Rua Carlos Gomes, 1217 São Paulo State University (UNESP) Department of Biological Sciences Faculty of Science São Paulo State University (UNESP) Department of Biological Sciences School of Pharmaceutical Sciences, Campus Araraquara São Paulo State University (UNESP) Department of Drugs and Medicines School of Pharmaceutical Sciences, Campus Araraquara

This study investigated the microbial synthesis of Ag/AgCl nanoparticles, their mutagenicity, antimutagenicity and antibacterial effects. For this purpose, bacteria isolates were taken from soil samples of Zarshouran gold mine. One silver resistant bacterial strain was selected for the production of silver nanoparticles. Results of the phylogenetic analysis showed that the strain ZAR1 was 99% similar to Staphylococcus pasteuri. The synthesis of the nanoparticles was confirmed using UV–vis spectroscopy, FTIR, XRD, DLS, and SEM-EDX. The analysis of the nanoparticles synthesized with extracellular extract of bacteria showed that the nanoparticles were spherical with a size of approximately 20–85 nm. Also, the ability of TSB media for the synthesis of silver nanoparticles was evaluated. The formation of Ag/AgCl nanoparticle composites was detected cubic form in the range of 20–50 nm. Antibacterial activity of the nanoparticles was determined against sixty-six pathogenic bacteria. Our results indicated that the nanoparticles had high antimicrobial activity against pathogenic bacteria. Moreover, the nanoparticles stabilized using sodium alginate showed high antimicrobial effects. Ames test revealed that Ag NPs did not display a mutagenic effect. Moreover, the results showed that the nanoparticles were antimutagenic. The percent inhibition of mutagenicity was approximate 97–99%.

Background The chemical quality of drinking water is widely unknown in low-income countries. Objective We conducted an exploratory study in Manhica district (Mozambique) to evaluate drinking water quality using chemical analyses and cell-based assays. Methods We measured nitrate, fluoride, metals, pesticides, disinfection by-products, and industrial organochlorinated chemicals, and conducted the bioassays Ames test for mutagenicity, micronuclei assay (MN-FACS), ER-CALUX, and antiAR-CALUX in 20 water samples from protected and unprotected sources. Results Nitrate was present in all samples (median 7.5 mg/L). Manganese, cobalt, chromium, aluminium, and barium were present in 90-100% of the samples, with median values of 32, 0.6, 2.0, 61, 250 μg/l, respectively. Manganese was above 50 μg/l (EU guideline) in eight samples. Arsenic, lead, nickel, iron, and selenium median values were below the quantification limit. Antimony, cadmium, copper, mercury, zinc and silver were not present. Trihalomethanes, haloacetic acids, haloacetonitriles and haloketones were present in 5-28% samples at levels ≤4.6 μg/l. DDT, dieldrin, diuron, and pirimiphos-methyl were quantified in 2, 3, 3, and 1 sample, respectively (range 12-60 ng/L). Fluoride was present in one sample (0.11 mg/l). Trichloroethene and tetrachloroethene were not present. Samples were negative in the in vitro assays. Significance Results suggest low exposure to chemicals, mutagenicity, genotoxicity and endocrine disruption through drinking water in Manhica population. High concentration of manganese in some samples warrants confirmatory studies, given the potential link to impaired neurodevelopment.

Dioscorea Rhizome is commonly used in traditional herbal medicines for the treatment of diabetes, hyperthyroidism, liver damage, neuropathy, and asthma. Here, we investigated the genotoxicity potential of D. Rhizome water extract (DRWE) using three standard battery systems in accordance with the test guidelines of the Organisation for Economic Cooperation and Development and Ministry of Food and Drug Safety as well as the principles of Good Laboratory Practice. A bacterial reverse mutation test (Ames test) was performed using the direct plate incorporation method in the presence or absence of a metabolic activation system (S9 mixture). The tester strains used included four histidine auxotrophic strains of Salmonella typhimurium, TA100, TA1535, TA98, and TA1537, along with a tryptophan auxotrophic strain of Escherichia coli, WP2 uvrA. An in vitro chromosome aberration test was performed using CHL/IU cells originally derived from the lung of a female Chinese hamster in the presence or absence of the S9 mixture. An in vivo mouse bone marrow micronucleus test was performed using male ICR mice. The micronucleus was confirmed after observation of the micro-nucleated polychromatic. The Ames test showed that DRWE did not induce gene mutations at any dose level in any of the tested strains. Additionally, DRWE did not result in any chromosomal aberrations specified in the in vitro chromosomal aberration and in vivo micronucleus tests. These results showed that DRWE exhibited neither mutagenic nor clastogenic potential in either the in vitro or in vivo test systems.

When testing new products, potential new products, or their impurities for genotoxicity in the Ames test, the quantity available for testing can be a limiting factor. This is the case for a dye repository of around 98,000 substances the Max Weaver Dye Library (MWDL). Mutagenicity data on dyes in the literature, although vast, in several cases is not reliable, compromising the performance of the in silico models. In this report, we propose a strategy for the generation of high-quality mutagenicity data for dyes using a minimum amount of sample. We evaluated 15 dyes from different chemical classes selected from 150 representative dyes of the MWDL. The purity and molecular confirmation of each dye were determined, and the microplate agar protocol (MPA) was used. Dyes were tested at the limit of solubility in single and concentration-response experiments using seven strains without and with metabolic activation except for anthraquinone dyes which were tested with eight strains. Six dyes were mutagenic. The most sensitive was YG1041, followed by TA97a > TA98 > TA100 = TA1538 > TA102. YG7108 as well as TA1537 did not detect any mutagenic response. We concluded that the MPA was successful in identifying the mutagenicity of dyes using less than 12.5 mg of sample. We propose that dyes should be tested in a tiered approach using YG1041 followed by TA97a, TA98, and TA100 in concentration-response experiments. This work provides additional information on the dye mutagenicity database available in the literature.

Introduction: Edible and medicinal plants contain active principles that can act as antimutagens, and hence their intake may be useful for human cancer prevention. Green leafy vegetables are important sources of carotenoids which possess antioxidant, anti-inflammatory and antimutagenic properties. Objective: To study the antimutagenic activity of oxycarotenoid-rich extracts isolated from Coriandrum sativum (coriander leaves) and Murraya koenigii (curry leaves). Methods: Oxycarotenoid-rich extracts isolated from Coriandrum sativum (coriander leaves) and Murraya koenigii (curry leaves) were investigated for antimutagenic activity in vitro by Ames test using Salmonella typhimurium strains TA 98 and TA 1535. Mutagens used were, nitro-o- phenylenediamine (NPD) (20μg/plate) and N-methyl- N-nitro-N-nitrosoguanidine (MNNG) (1μg/ plate). Results: The results revealed that oxycarotenoid-rich extracts isolated from Coriandrum sativum (coriander leaves) and Murraya koenigii (curry leaves) administered at doses of 1.0 mg, 2.5 mg and 5 mg per plate significantly inhibited mutagenicity induced by NPD and MNNG.Conclusion: These findings suggest that oxycarotenoid- rich extracts isolated from Coriandrum sativum (coriander leaves) and Murraya koenigii (curry leaves) have antimutagenic properties.

Graphical abstract, Highlights • The P2Et extract was assessed for genotoxicity and mutagenicity activity. • The P2Et extract showed no genotoxicity in Micronucleus assay. • The P2Et extract showed no mutagenicity in Ames test., The standardized P2Et extract obtained from Caesalpinia spinosa has shown antioxidant, and direct antitumor activity, but also activation of specific immune response through the induction of tumor immunogenic cell death in breast and melanoma cancer models. The present work evaluated the mutagenicity and genotoxicity profile of P2Et to continue the development of the P2Et. Genotoxicity was evaluated by OECD 1997 a guideline and mutagenicity by OECD 2016. At P2Et’s doses of 500, 1000, and 2000 mg/kg body weight in mice (Mus musculus), the difference between the number of micronuclei in PCE of the groups were not statistically significant (17 (negative control), 15 (500 mg/kg), 15 (1000 mg/kg), 19 (2000 mg/kg) and 271 (positive control). Similarly, P2Et did not induce gene mutations by base pair changes or frameshifts in the genome of Salmonella Typhimurium strains TA98, TA100, TA102, TA1535 and TA1537 at the tested range of concentrations up to 5000 μg/plate in the absence and presence of metabolic activation. Therefore, the P2Et was considered as non- mutagenic and non-genotoxic at the conditions of the tests.

Dialysed latex C-serum supernatant (DCS) sub-fraction from the rubber tree (Hevea brasiliensis) was reported to exert significant anti-proliferative effect on specific cancer cell lines, especially in human triple negative breast cancer (MDA-MB-231) and human liver carcinoma (HepG2) cells. In the present study, two human non-cancer origin cell lines, MCF-10A (human breast epithelial cells) and HDFa (human adult dermal fibroblast cells), showed least susceptibility when treated with DCS sub-fraction at concentration range 0–100 µg/mL using 2,5-diphenyl tetrazolium bromide (MTT) assay. Genotoxicity of DCS sub-fraction was assessed through Ames test, in vitro mouse lymphoma assay, and in vitro micronucleus assay. All genotoxicity experiments were tested with the presence and absence of S9 mixture as metabolic activation system. Ames test results showed negative result of mutagenicity as no clear dose-dependent relationship was observed despite mutagenic potential was detected in frame shift-based TA98 and TA1535 Salmonella typhimurium strains. Mouse lymphoma assay produced non-linear dose-dependent effect in experiments without the presence of S9. Meanwhile, experiment with the presence of S9 resulted in an inverse effect of the dose-dependent relationship. In micronucleus assay, the dose-dependent cytotoxicity effect of DCS sub-fraction showed no correlation with the increase number of cells containing micronuclei but appeared to be time-dependent. In conclusion, DCS sub-fraction showed no significant positive results in genotoxicity assays. In vivo genotoxicity assays should be conducted to ensure the safe use of DCS sub-fraction in further exploration for biological applications.

1,2-unsaturated pyrrolizidine alkaloids (PAs) are natural plant constituents comprising more than 600 different structures. A major source of human exposure is thought to be cross-contamination of food, feed and phytomedicines with PA plants. In humans, laboratory and farm animals, certain PAs exert pronounced liver toxicity and can induce malignant liver tumors in rodents. Here, we investigated the cytotoxicity and genotoxicity of eleven PAs belonging to different structural classes. Although all PAs were negative in the fluctuation Ames test in Salmonella, they were cytotoxic and induced micronuclei in human HepG2 hepatoblastoma cells over-expressing human cytochrome P450 3A4. Lasiocarpine and cyclic diesters except monocrotaline were the most potent congeners both in cytotoxicity and micronucleus assays with concentrations below 3 μM inducing a doubling in micronuclei counts. Other open di-esters and all monoesters exhibited weaker or much weaker geno- and cytotoxicity. The findings were in agreement with recently suggested interim Relative Potency (iREP) factors with the exceptions of europine and monocrotaline. A more detailed micronuclei analysis at low concentrations of lasiocarpine, retrorsine or senecionine indicated that pronounced hypolinearity of the concentration–response curves was evident for retrorsine and senecionine but not for lasiocarpine. Our findings show that the genotoxic and cytotoxic potencies of PAs in a human hepatic cell line vary in a structure-dependent manner. Both the low potency of monoesters and the shape of prototype concentration–response relationships warrant a substance- and structure-specific approach in the risk assessment of PAs. Electronic supplementary material The online version of this article (10.1007/s00204-020-02895-z) contains supplementary material, which is available to authorized users.

The study of new antimicrobial compounds includes determining the mechanism of their effect on the microbial cell. As a rule, an effect for the majority of current synthetic antimicrobials is associated either with suppressed DNA synthesis, or with inhibiting bacterial protein production at translational or transcriptional level. A number of sensitive and easy-todo methods are available for screening and monitoring potential genotoxic activity of a wide range of natural and synthetic compounds. To date, the Ames test has been widely used, which is based on the sensitivity of Salmonella strains to carcinogenic chemicals, although some compounds resulting in Ames negative reactions could actually be carcinogenic to animals. Likewise, the SOS chromotest represents a SOS transcriptional analysis able to assess DNA damage caused by chemical and physical mutagens by measuring the expression of a reporter gene (β-galactosidase) encoding the β-galactosidase enzyme that metabolizes ortho-nitrophenyl galactopyranoside resulting in emerging a yellow-colored compound detected at wavelength 420 nm. Next, the induction of β-galactosidase is normalized by the activity of alkaline phosphatase, an enzyme expressed constitutively by Escherichia coli. SOS chromotest is also widely used for genotoxicological studies providing a quick answer (several hours) and requiring no survival of the test strain. Dose-response curves for various chemicals consist of a linear region, which slope corresponds to the SOS induction. Therefore, the SOS chromotest was selected for the study allowing to identify DNA-mediated effects of the analyzed compounds. The aim of the study was to evaluate the SOSinducing activity for 1H-indol-4-, -5-, -6-, -7-ylamines-substituted antimicrobial compounds. The Escherichia coli PQ 37 with the genotype F-thr leu his-4 pyrD thi galE lacΔU169 srl300::Th10 rpoB rpsL uvrA rfa trp::Mis+ sfiA:: Mud (Ar, lac) cts was used as a test strain. Due to the link of the sfi A::lac Z genes, lacZ β-galactosidase gene expression in the strain PQ 37 is controlled by the sfiA gene promoter, one of the components in the E. coli SOS regulon. Activity of β-galactosidase assessed relative to constitutive microbial alkaline phosphatase reflects SOS-inducing activity triggered by examined compounds in the SOS chromotest that also allows to control their toxic effects on bacterial cells. The data showed that 4,4,4-trifluoroN-(6-methoxy-1,2,3-trimethyl-1H-indol-5-yl)-3-oxobutanamide (1), 4,4,4-trifluoro-N-(6-methyl-2-phenyl-1H-indol-5-yl)- 3-oxobutanamide (2) and N-(1,5-dimethyl-2-phenyl-1H-indol-6-yl)-4,4,4-trifluoro-3-oxobutanamide (3) exerted no SOSinducing activity at the examined concentrations. In contrast, 4-Hydroxy-8-phenyl-4-(trifluoromethyl)-1,3,4,7-tetrahydro- 2H-pyrrolo [2,3-h]-quinoliN-2-one (4), 9-hydroxy-5-methyl-2-phenyl-9-(trifluoromethyl)-1,6,8,9-tetrahydro-7Н-pyrrolo- [2,3-f]-quinoliN-7-one (5), 6-hydroxy-2,3-dimethyl-6-(trifluoromethyl)-1,6,7,9-tetrahydro-8H-pyrrolo[3,2-h]quinoliN-8- one (6) and 1,2,3,9-tetramethyl-6-(trifluoromethyl)-1,9-dihydro-8H-pyrrolo [3,2-h]-quinoliN-8-one (7) displayed a dosedependent SOS-inducing activity at bactericidal concentrations. The data obtained allowed us to identify compounds 4, 5, 6, 7, which mechanism of action relies on affecting microbial cell DNA.

14-O-[(4,6-Diaminopyrimidine-2-yl)thioacetyl] mutilin (DPTM) is a promising drug candidate with excellent antibacterial activity against Gram-positive bacteria. The present study was designed to characterize its Cytochrome P450 (CYP) enzymes inhibition activities and the genotoxicity with the standard Ames test. We determined the inhibitory effects of DPTM on CYP1A2, CYP2D1/6, CYP2E1, CYP2C11/9 and CYP3A/4 in rat liver microsomes (RLMs) and in human liver microsomes (HLMs). The mRNA expressions of the above CYP isoforms and their transcriptional regulators were also evaluated using the Hep G2 cell model. The results showed DPTM exhibited a moderate inhibitory potential against CYP3A/4 (IC50 values of 10 ± 2 and 8 ± 2 μM, respectively) and weak against the other CYP enzymes based on their IC50 values. Compared to the control, CYP isoforms and their transcriptional regulators mRNA expressions significantly increased when the Hep G2 cells were treated with DPTM for a certain period of time. In the Ames test, Salmonella strains TA97, TA98, TA100, TA102 and TA1535 were treated with or without the metabolic activation (S9). Analysis showed the average number of revertant colonies per plate was less in double in the groups treated with DPTM than that in the negative control plate and showed no dose-related increase.

Background Taraxacum species (commonly known as dandelion) used as herbal medicine have been reported to exhibit an antiproliferative effect on hepatoma cells and antitumor activity in non-small-cell lung cancer cells. Although several investigations have demonstrated the safety of Taraxacum officinale, the safety of tissue-cultured plants of T. formosanum has not been assessed so far. Therefore, the present study examines the safety of the water extract of the entire plant of tissue cultured T. formosanum based on acute and subacute toxicity tests in rats, as well as the Ames tests. Results No death or toxicity symptoms were observed in the acute and subacute tests. The results of the acute test revealed that the LD50 (50% of lethal dose) value of the T. formosanum water extract for rats exceeded 5 g/kg bw. No abnormal changes in the body weight, weekly food consumption, organ weight, or hematological, biochemical, and morphological parameters were observed in the subacute toxicity test. Thus, the no observed adverse effect level (NOAEL) of T. formosanum water extract was estimated to be higher than 2.0 g/kg. Finally, the results of the Ames test revealed that T. formosanum water extract was not genotoxic at any tested concentration to any of five Salmonella strains. Conclusions The water extract of tissue-cultured T. formosanum was non-toxic to rats in acute and subacute tests and exhibited no genotoxicity to five Salmonella strains. How to cite: Tsai WC, Chang HC, Tseng YH, et al. Toxicity evaluation of water extract of tissue-cultured Taraxacum formosanum by acute, subacute administration, and Ames test. Electron J Biotechnol 2020;45. https://doi.org/10.1016/j.ejbt.2020.04.001

Abstract Indole alkaloids extract (IAAS) was prepared from leaves of Alstonia scholaris (L.) R. Br., an evergreen tropical plant widely distributed throughout the world. This plant has been used historically by the Dai ethnic people of China to treat respiratory diseases. This study evaluated the genotoxicity and safety pharmacology of IAAS to support clinical use. The bacterial reverse mutation (Ames) test, in vitro mammalian chromosomal aberration test, and in vivo mammalian erythrocyte micronucleus (MN) test were performed to evaluate genotoxicity. Mice were administered IAAS (240, 480, or 960 mg/kg bw) once orally to observe adverse central nervous system effects. Furthermore, beagle dogs were administered IAAS (10, 30, 60 mg/kg bw) once via the duodenum to evaluate its effects on the cardiovascular and respiratory systems. IAAS with or without S9-induced metabolic activation showed no genotoxicity in the Ames test up to 500 μg/plate, in the mammalian chromosomal aberration test up to 710 μg/mL, or in the MN test up to 800 mg/kg bw. No abnormal neurobehavioral effects were observed in mice following treatment with up to 960 mg/kg bw of IAAS. Moreover, blood pressure, heart rate, electrocardiogram parameters, and depth and rate of breathing in anesthetized beagle dogs did not differ among the IAAS doses or from the vehicle group. These data indicated that IAAS did not induce mutagenicity, clastogenicity, or genotoxicity, and no pharmaco-toxicological effects were observed in the respiratory, cardiovascular, or central nervous systems. Our results increased understanding of safety considerations associated with IAAS, and may indicate that IAAS is a possible drug candidate. Graphic Abstract

Probiotic Escherichia coli strain Nissle 1917 (EcN) has a long history of safe use. However, the recently discovered presence of a pks locus in its genome presumably producing colibactin has questioned its safety, as colibactin has been implicated in genotoxicity. Here, we assess the genotoxic potential of EcN. Metabolic products were tested in vitro by the Ames test, a mutagenicity assay developed to detect point mutation-inducing activity. Live EcN were tested by an adapted Ames test. Neither the standard nor the adapted Ames test resulted in increased numbers of revertant colonies, indicating that EcN metabolites or viable cells lacked mutagenic activity. The in vivo Mammalian Alkaline Comet Assay (the gold standard for detecting DNA-strand breaks) was used to determine potentially induced DNA-strand breaks in cells of the gastro-intestinal tract of rats orally administered with viable EcN. Bacteria were given at 109–1011 colony forming units (CFU) per animal by oral gavage on 2 consecutive days and daily for a period of 28 days to 5 rats per group. No significant differences compared to negative controls were found. These results demonstrate that EcN does not induce DNA-strand breaks and does not have any detectable genotoxic potential in the test animals.

Rheum emodi Wall. Ex. Meissen is an important food and medicinal plant growing wild in western Himalayas. The current endeavor was undertaken to carry out bioassay guided fractionation and isolation of antimutagenic principle(s) present in the rhizomes of Rheum emodi. The antimutagenicity assay was performed to check the recuperating effect of 80% aqueous methanol extract of rhizomes of R. emodi and its fractions i.e. n-hexane, chloroform, ethyl acetate, n-butanol and water fractions, against 4-nitro-o-phenylenediamine (NPD), sodium azide, and 2AF-induced mutagenicity in TA98 and TA100 strains using the Ames Salmonella his+ reversion assay. The crude 80% aqueous methanol extract and ethyl acetate fraction exhibited strong antimutagenicity. The antimutagenic potential of the extracts and fractions was markedly enhanced when indirect acting mutagen was used in both the tester strains of Salmonella typhimurium. In an effort to identify the molecules responsible for the antimutagenic effect displayed by R. emodi, four anthraquinones i.e. aloe-emodin, chrysophanol, emodin and rhein detected in the ethyl acetate fraction by HPLC analysis were also tested for their antimutagenic potential in both the tester strains. It was found that the anthraquinones in their pure form showed lower antimutagenicity than the mother fraction from which they were isolated. The results point towards a synergistic effect of the principles present in the mother fraction.

A comparative analysis was performed of the impact on living organisms, in terms of genotoxicity, of two factors, namely, radiation (residual 137Cs) and a chemical factor (pesticides) . The experiment was conducted both on individual pesticide samples and the aqueous extracts of soil samples. Soil samples were collected in the territory of the Orel region (Russia) from May 12 to May 15, 2010, i.e., years after the Chernobyl accident. Changes in the mutagenic index derived from Ames assay (Salmonella/microsomes) and the data obtained from mammalian cell culture in the Cricetulus griseus test (Chinese hamster) of the soil samples arising from the cesium radioactivity and the content of pesticides in these samples were considered. No direct correlation was found between dose level and genotoxicity at low radiation doses (20 μR/h), i.e., correlation with DNA mutations produced, both in terms of frameshifting and the base replacement type. On the contrary, a clear tendency was observed for increase in genotoxicity with increase in the concentration of pesticides and the entire amount of anthropogenic toxicants in the studied soil samples.

Graphical abstract, Highlights • Imidacloprid, imazalil, tebuconazole were non-genotoxic separately. • The mixture of imidacloprid + imazalil + tebuconazole was negative in Ames test. • The mixture induced a statistically significant increase in MN-PCEs in bone marrow. • The effect observed in vivo is probably mediated by synergism of TGAIs., Genotoxicity of the mixture of generic pesticides imidacloprid + imazalil + tebuconazole in a ratio of 14.0/1.7/1.0 by weight was assessed using Ames test (Salmonella typhimurium) and micronucleus test in vivo on mammalian bone marrow erythrocytes (CD-1 mice) supporting the data creation for the Real Life Risk Simulation (RLRS) approach. This pesticides’ combination is used in the commercial formulation for seed treatment in advance of or immediately before sowing. Tested pesticides’ technical grade active ingredients (TGAIs) showed no evidence of genotoxicity upon separate treatments. In combination, the three pesticides demonstrated negative results in the Ames test but induced a statistically significant, dose-depended increase in MN-PCEs in mice bone marrow at doses lower than those used separately. The observed effect may be mediated by the synergistic action of the tested TGAIs, their metabolites or impurities.

l-threonine, l-tryptophan and l-valine play a fundamental role in animal and human nutrition as essential amino acids required for normal growth. In addition, each amino acid is codified as a generally recognized as safe (GRAS) amino acid for the use in animal feed additives and presents no exposure risk from animal to humans consuming tissues or products from the target animal. Taking into account the important role of mutagenicity and genotoxicity in the risk of the three amino acid additives (l-threonine, l-tryptophan, and l-valine) fermentation products and other unknown impurities and derivatives from Corynebacterium glutamicum (C. glutamicum), the safety evaluation of these amino acid additives is not performed. Therefore, the purpose of this study is to evaluate toxicological effects, including Ames test, an in vitro mammalian chromosomal aberration test and an acute oral animal toxicity of the three amino acid additives in accordance with the Organisation for Economic Co-operation and Development (OECD) guidelines and the principles of Good Laboratory Practice (GLP). As a result, these amino acid additives were classified as non-mutagenic and non-clastogenic, and did not induce any toxicity in acute oral toxicity test. Collectively, these results suggest that the three amino acid additives are safe with no adverse effects, and able to be applied as an ingredient or other biological uses.

Cannabinoids are extracted from Cannabis sativa L. and are used for a variety of medicinal purposes. Recently, there has been a focus on the cannabinoid Cannabidiol (CBD) and its potential benefits. This study investigated the safety of a proprietary extract of C. sativa, consisting of 9% hemp extract (of which 6.27% is CBD) and 91% olive oil. The mutagenic potential of the hemp extract was evaluated with the AMES assay inclusive of a hepatic drug metabolizing mix (S9) rich in CYP enzymes. The test article did not elicit evidence of bacterial mutagenicity. GLP compliant 14-day and a 90-day toxicity study were conducted. Olive oil was used as a control. The 90-day study had a 28-day recovery period. Treatments for the 14-day non-recovery range-finding study were 0, 1000, 2000 and 4000 mg test article/kg body weight (bw)/day for 14 days. There was a non-statistically significant (p > 0.05) decrease in body weights for the male and female rats receiving the test article. Hypoactivity, hyperactivity, reduced food consumption and piloerection were observed in the rats receiving 4000 mg test article/kg bw. Histopathology showed an increase in the size of liver cells (hypertrophy) around the central vein (centrilobular) in Groups 3 (3/10) and 4 (5/10) that correlated with increased liver weights. In the 90-day study, 8 groups of rats were dosed with 0, 200, 400 and 800 mg test article/kg bw/day. Groups 5 to 8 had a 28-day recovery. There were no test article-linked changes in clinical observations, physical examinations, Functional Observation Battery, ophthalmology, Motor Activity Assessment, hematology, clinical chemistries and macropathology (all groups). With the exception of the liver and adrenal gland, no test article-linked pathology was observed. For all rats receiving the test article, histopathology showed hypertrophy of liver cells around the central vein. The increase of liver weight is most likely caused by hypertrophy due to up-regulation of the hepatic drug metabolizing enzymes. The hepatocellular hypertrophy was completely reversed in 28 days and was not considered to be an adverse effect. Vacuolization of the adrenal zona fasciculata was observed in the control and 800 mg test article/kg bw groups. The vacuolization of the zona fasciculata was of the same incidence and severity in treatment and control male rats and correlated with an increased in the weights of the adrenal glands. In addition, a statistically significant increase (p

Arabinase is an enzyme recognized for its ability to degrade arabinan, a plant cell wall constituent. It has been applied in the food industry most commonly for juice processing. One commercial source of arabinase is Aspergillus tubingensis (A. tubingensis), a black Aspergillus species. Given the intended use in food for human consumption, and noting its potential presence at trace levels in finished products, a series of safety studies including in vitro Ames and chromosome aberration assays, in vivo mammalian erythrocyte micronucleus and alkaline comet assays, and a 90‐day rat oral toxicity study were conducted. No test article‐related mutagenic activity was observed in the Ames assay. Although positive activity was observed in the chromosome aberration assay, this was not replicated in the in vivo genotoxicity assays including in preabsorptive cells. In the subchronic toxicity study, no test article‐related adverse effects were observed following oral administration of arabinase at doses of 15.3, 153, or 1,530 mg total organic solids (TOS)/kg body weight/day to Sprague Dawley rats. The no‐observed‐adverse‐effect level was considered to be the highest dose tested (1,530 mg TOS/kg body weight/day). The results of the genotoxicity studies and the subchronic toxicity study support the safe use of arabinase from A. tubingensis in food production., A series of toxicological studies including in vitro and in vivo short‐term genotoxicity assays and a 90‐day subchronic oral toxicity study were conducted to evaluate the safety of arabinase from Aspergillus tubingensis. Arabinase was concluded to be nongenotoxic and was not associated with toxicity in rats at the highest dose tested (up to 1,530 mg TOS/kg body weight/day). Study results provide reassurance of the safety of use of arabinase from A. tubingensis in food production.

—Limonium plants have commonly used as antibacterial, styptical, anti-swelling agent, digestive system regulator, anticarcinogenic, and antiviral in alternative medicine. Beside this, different extracts of Limonium plants have mutagenic, cytotoxic and genotoxic effects. Different parts of Limonium effusum (Boiss.) Kuntze ethanol extracts were used to determine the mutagenic and cytotoxic effects. Ames test was carried out with Salmonella typhimurium TA98, and TA100 strains to determine the mutagenicity. Ames test results showed that root 1000 μg/plate of plant has mutagenic effect and root extracts have weak mutagenicity with TA98 strain. MTT test was carried out with MDBK (Madin-Darby Bovine Kidney) cells to determine the cytotoxicity. Cytotoxicity results showed that root 50, 25, 12.5 and 6.25 μg/mL extracts were increased the proliferation rates in 24 h treatment. All doses of root extracts decreased the rates in 96 h. All concentrations of stem decreased the proliferation rates in 96 h. Leaf extracts increased the rates in 24 h but decreased in 48, 72, and 96 h.

Cytogenetic methods based on the analysis of chromosome changes in somatic mammalian cells are promising techniques for the early recognition of toxic effects arising from anthropogenic pollution of environmental objects. The genetic changes in somatic cells are an integral parameter of the mutagenic effect of the environment and the effectiveness of the immune system of organisms. In this work, the method of analysis of toxic properties based on determining the frequency and types of chromosomal aberrations during the short-term (within 2 h) exposure of mammalian cell cultures to a test water sample is used to study the toxic properties of natural and waste water with different levels of anthropogenic pollution. It is shown that the contribution to the genotoxicity of the analyzed native water samples from water-soluble substances that cannot be extracted with a mixture of hexane and ethyl ether can reach 50–75%, while the contribution of organic substances extracted with organic solvents can be only 2–3%. Water-soluble compounds of reduced sulfur play a key role in the formation of toxic properties of natural and waste waters. Using benzo[a]pyrene and 3,3',4,4'-tetrachlorobiphenyl (PCB 77) as an example, it is found that the genotoxic properties of even the most hydrophobic toxicants are determined by their dissolved form and can manifest themselves starting from a concentration of 10 ng/L. A comparative analysis with the Ames test, which is widely used in the study of the mutagenic activity of various toxicants, indicates that the cytogenetic method is a much more informative and sensitive method for monitoring the chemical safety of water bodies.

Introduction. One of the important steps in assessing the nanoparticles (NP) safety is the analysis of mutagenic activity, including the evaluation of gene, chromosomal, and genomic mutations. Material and methods. The purpose of this investigation is to study the ability of different NP aqueus suspensions and the same compounds in microforms to unduce gene mutations in Salmonella/microsome test (Ames test). Anatase titanium dioxide NP coated with simethicone (33.16 ± 16.7 nm, 5-50000 μg/ml), magnetite NP coated with silicate (10 nm, 0.92-575 μg/ml), silver NP coated with аrabian gum (14 ± 0.2 nm, 5-50000 μg/ml), aluminum hydroxide nanofibres (50-70 nm, 24-3000 μg/ml) and multi-walled carbon nanotubes (Taunit MWСNTs, outer diameter 15-40 nm, inner diameter 3-8 nm, length 2 and more microns, 5-50000 μg/ml). In parallel, the mutagenic activity of equivalent microparticles was evaluated in experiments. Ames test (Salmonella/microsomes) registers gene mutations induced by a different mechanism of action, in the variant with preincubation. A set of Salmonella typhimurium indicator strains: TA 100 (base pair substitution mutations), TA 98 and TA 97 (mutations of the frameshift type of the genetic code) were used. Using addition the S9 microsomal activating mixture during the experiment makes it is possible to determine the effect not only of the substances themselves, but also of their metabolites. Conclusion. The investigated nanomaterials as well as their micro analogs in the studied dose range did not induce gene mutations in the Ames test both in presence and absence microsomal activating mixture.

Background: Ginsenosides have been widely used clinically for many years and were regarded as very safe. However, a few researches on the toxicities of these kinds of agents showed that some ginsenosides may have side-effect on the rats or dogs. So it is extremely necessary to further clarify the potential toxicity of ginsenosides. This study was carried out to investigate long-term toxicity and genotoxicity of 25-methoxydammarane-3, 12, 20-triol (25-OCH3-PPD), a new derivative of ginsenoside, in beagle dogs. Methods: Twenty-four beagle dogs were divided randomly into four treatment groups and repeatedly orally administered with 25-OCH3-PPD capsule at 60, 120, and 240 mg/kg/day for 91 consecutive days. Ames, micronucleus, and chromosomal aberration tests were established to analyze the possible genotoxicity of 25-OCH3-PPD. Results: There was no 25-OCH3-PPD–induced systemic toxicity in beagle dogs at any doses. The level of 25-OCH3-PPD at which no adverse effects were observed was found to be 240 mg/kg/day. The result of Ames test showed that there was no significant increase in the number of revertant colonies of 25-OCH3-PPD administrated groups compared to the vehicle control group. There were also no significant differences between 25-OCH3-PPD administrated groups at all dose levels and negative group in the micronucleus test and chromosomal aberration assay. Conclusion: The highest dose level of 25-OCH3-PPD at which no adverse effects were observed was found to be 240 mg/kg per day, and it is not a genotoxic agent either in somatic cells or germs cells. 25-OCH3-PPD is an extremely safe candidate compound for antitumor treatment. Keywords: Beagle dog, Subchronic toxicity, Ginsenoside

Excessive UV exposure contributes to several pathological conditions like skin burns, erythema, premature skin aging, photodermatoses, immunosuppression, and skin carcinogenesis. Effective protection from UV radiation may be achieved with the use of sunscreens containing UV filters. Currently used UV filters are characterized by some limitations including systemic absorption, endocrine disruption, skin allergy induction, and cytotoxicity. In the research centers all over the world new molecules are developed to improve the safety, photostability, solubility, and absorption profile of new derivatives. In our study, we designed and synthesized seventeen novel molecules by combining in the structures two chromophores: xanthone and (E)-cinnamoyl moiety. The ultraviolet spectroscopic properties of the tested compounds were confirmed in chloroform solutions. They acted as UVB or UVA/UVB absorbers. The most promising compound 9 (6-methoxy-9-oxo-9H-xanthen-2-yl)methyl (E)-3-(2,4-dimethoxyphenyl)acrylate) absorbed UV radiation in the range 290&ndash, 369 nm. Its photoprotective activity and functional photostability were further evaluated after wet milling and incorporation in the cream base. This tested formulation with compound 9 possessed very beneficial UV protection parameters (SPFin vitro of 19.69 &plusmn, 0.46 and UVA PF of 12.64 &plusmn, 0.32) which were similar as broad-spectrum UV filter tris-biphenyl triazine. Additionally, compound 9 was characterized by high values of critical wavelength (381 nm) and UVA/UVB ratio (0.830) thus it was a good candidate for broad-spectrum UV filter and it might protect skin against UVA-induced photoaging. Compound 9 were also shown to be photostable, non-cytotoxic at concentrations up to 50 &micro, M when tested on five cell lines, and non-mutagenic in Ames test. It also possessed no estrogenic activity, according to the results of MCF-7 breast cancer model. Additionally, its favorable lipophilicity (miLogP = 5.62) does not predispose it to penetrate across the skin after topical application.

The various species that comprise the genus Glycyrrhiza (Licorice) have long been used as oriental herbal medicines in Asian countries. Wongam (WG), which is a new variety of Glycyrrhiza, was developed in Korea to overcome the limitations of low productivity, environmental restrictions, and an insufficient presence of glycyrrhizic acid and liquiritigenin. In this study, we evaluated WG extract’s genotoxicity through an in vitro bacterial reverse mutation (AMES) test, an in vitro chromosome aberration test, and an in vivo mouse bone marrow micronucleus test. In the AMES test, WG extract at concentrations of up to 5000 µg/plate showed no genotoxicity regardless of S9 mix. No chromosome aberrations appeared after 6 h in 1400 µg/mL WG extract regardless of S9 mix or in 1100 µg/mL WG extract after 24 h without S9 mix. Nor was there a significant increase in the number of micronucleated polychromatic erythrocytes to total erythrocytes up to 5000 mg/kg/day for 2 days detected in the micronucleus test. These results confirm that WG extract is safe for use as an herbal medicine, as it precipitates no detectable genotoxic effects.

Several potential genotoxins found in water samples arise from anthropogenic activities. Acid mine effluent resulting from coal mining poses serious environment concerns all over the world. The use of toxicity tests to evaluate the quality of streams add value by providing site-specific toxicological data. Treatment systems such as the use of natural wetlands (passive) or conventional physical and chemical pH-neutralised processes (active) are employed mainly to meet certain water quality guidelines. Nonetheless, potential genotoxins or residues remain which influence the quality of discharged effluents. The objective of this study was to evaluate the genotoxic potential of acid mine drainage (AMD) released into a natural stream following treatment by passive and active methods. This study aimed to identify the extent of AMD mutagenicity and genotoxicity to African Vero monkey kidney cell line and a fish gill cell line (RTgill-W1) using two assays, the Ames test, and the comet assay, as a rapid and effective screening tool. The Ames test performed without metabolic activation using Salmonella typhimurium TA98 and TA100 strains showed no indication of mutagenicity in the water samples tested. Differing results were however obtained for the comet assay using the African Vero monkey kidney cell line and a fish gill cell line (Rtgill-W1), which revealed DNA fragmentation and variations in morphologies indicative of genotoxicity in the water samples following the two treatment processes. A significant reduction in DNA damage was observed in water samples following active treatment of the AMD, evidenced by reduced damage frequency and a lowered comet score. This bioassay confirms the urgency of integrating high-throughput screening in aquatic toxicity assessment at genetic levels, giving further evidence that in-vitro bioassays can be incorporated for use in short-term genotoxicity assays. The result suggests that the comet assay proved sensitive at detecting genotoxicity, supporting the integration of this into environmental monitoring frameworks targeted at AMD-contaminated sites.

Wildland fires, increasing in recent decades in the Mediterranean region due to climate change, can contribute to PM levels and composition. This study aimed to investigate biological effects of PM2.5 (Ø &lt, 2.5 µm) and PM10 (Ø &lt, 10 µm) collected near a fire occurred in the North-West of Italy in 2017 and in three other areas (urban and rural areas). Organic extracts were assessed for mutagenicity using Ames test (TA98 and TA100 strains), cell viability (WST-1 and LDH assays) and genotoxicity (Comet assay) with human bronchial cells (BEAS-2B) and estrogenic activity using a gene reporter assay (MELN cells). In all sites, high levels of PM10 and PM2.5 were measured during the fire suggesting that near and distant sites were influenced by fire pollutants. The PM10 and PM2.5 extracts induced a significant mutagenicity in all sites and the mutagenic effect was increased with respect to historical data. All extracts induced a slight increase of the estrogenic activity but a possible antagonistic activity of PM samples collected near fire was observed. No cytotoxicity or DNA damage was detected. Results confirm that fires could be relevant for human health, since they can worsen the air quality increasing PM concentrations, mutagenic and estrogenic effects.

In this research, mutagenic properties of blueberry polyphenol extract were studied in gene mutation induction test (Ames test) on four strains of Salmonella typhimurium TA98, TA100, TA1535, TA1537. None of the strains of Salmonella typhimurium showed statistically reliable dose-dependent increase in number of revertant colonies in the presence of investigated drug in the studied dose range from 4,0 to 40,0 mg/ml relative to baseline of spontaneous mutations. The blueberry extract does not have any mutagenic activity in the researched dose range in relation to TA98, TA100, TA1535, TA1537 strains of Salmonella typhimurium.

Made available in DSpace on 2022-04-29T08:33:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01 Dinitrophenylazo dyes can form 2-phenylbenzotriazoles (PBTAs) in the textile dyeing process upon the addition of chemical reducing agents. Some dinitrophenylazo dyes, as well as their respective reduced (non-chlorinated) and chlorinated PBTAs, are now found in rivers owing to wastewater from textile plants. This study aimed to investigate the genotoxicity of a new PBTA derived from C.I. Disperse Violet 93 azo dye, namely non-Cl PBTA-9. Primary DNA damage in the blood, liver, and colon cells, micronucleated cells in the bone marrow, and gene expression (NAT2, CYP1A1, TRP53, and CDKN1A) in liver cells were observed in mice, at acute oral exposure (gavage) doses of 5, 50, and 500 μg/kg body weight (b.w.). The non-chlorinated PBTA-9 caused DNA damage in the blood and liver (at 500 μg/kg b.w.) and in colon cells (at 5, 50, and 500 μg/kg), and increased the frequency of micronucleated cells in the bone marrow (at 5 and 50 μg/kg). No histological alterations or gene expression changes were observed. In conclusion, in vivo exposure to non-chlorinated PBTA-9 induced genetic damage in various rodent tissues, corroborating results previously obtained from the Ames test. Because this compound has been detected in rivers, exposure to humans and biota is a major concern. Department of Pathology Medical School São Paulo State University (UNESP) National Institute for Alternative Technologies of Detection Toxicological Evaluation and Removal of Micropollutants and Radioactives (INCT-DATREM) Institute of Chemistry School of Technology State University of Campinas (UNICAMP) School of Veterinary and Zootechnics São Paulo State University (UNESP) Department of Pathology Medical School São Paulo State University (UNESP) School of Veterinary and Zootechnics São Paulo State University (UNESP)

Preparation and comprehensive characterization of three Schiff base ligands; with trimethoxy substitution (1E,1'E)-N,N'-(naphthalene-1,5-diyl)bis(1-(3,4,5-trimethoxyphenyl)methanimine), 1, with ortho-hydroxy substitution 6,6'-((1E,1'E)-(naphthalene-1,5-diylbis(azaneylylidene))bis(methaneylyl- idene))bis(2-methoxyphenol), 2 and 3,4-bis(((E)-2-hydroxy-3-methoxybenzylidene)amino)benzoic- acid, 3 and their Ni(II), Cu(II), Co(II), Zn(II), Fe(II), Mn(II) complexes have been reported. Their spectral properties were studied in solution and solid-state by a combination of different analytical techniques; FT-IR spectroscopy, 1H-NMR and 13C-NMR spectroscopy, elemental analysis and thermal analysis. Diamagnetic and paramagnetic natures of the complexes were also determined by magnetic susceptibility measurements in solid-state. Promising photophysical properties were observed as; Amax. were recorded at 226 nm for 2; at 795 nm for 2-Ni, at 782 nm for 2-Cu, at 784 nm for 2-Co, at 702 nm for 2-Zn, at 784 nm for 2-Fe, at 702 nm for 2-Mn and at 289 nm for 3, at 786 nm for 3-Ni, at 797 nm for 3-Cu, at 746 nm for 3-Co, at 794 nm for 3-Zn, at 699 nm for 3-Fe, at 781 nm for 3-Mn ; and Imax were also recorded at; 380, 490, 725 nm for 2 and 2-Metal; 375 nm, 510 nm, 725 nm for 3 and 3-Metal when excitated at 220 nm. Antibacterial activities against different microorganisms; Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70603, Staphylococcus aureus ATCC 43300 (MRSA), Salmonella enteritidis ATTC 13076, Sarcina lutea ATCC 9341, Bacillus cereus ATTC 11778, and antifungal activities against Candida albicans NRRL Y-417 of the compounds 1, 2, 3, 2-Cu, 2-Fe, 3-Zn, 3-Fe were determined. Mutagenic properties of the compounds were also studied and according to the results 2-Cu and 3 have been found non-mutagenic in Ames test but also they have strong antimicrobial potential against pathogen microorganisms. For 2-Cu MIC values were ranging between 0.39-0.024 mg/ml and the lowest minimum inhibitory concentration (0.024 mg/ml) was determined against E. coli. The 3 numbered compound revealed strong antimicrobial activity at doses of ranging between 0.39-0.097 mg/ml and E. coli was the most sensitive bacterium against this chemical.

Pesticide adjuvants (PAs) denote the general term for auxiliaries in pesticide preparations except for the active components. Toluene, chloroform, and trichloroethylene are the three most commonly used PAs as organic solvents. The residues of the three chemicals in the process of production and application of pesticides may endanger the ecosystem. In the present study, the mutagenicity of toluene, chloroform, and trichloroethylene as well the mixture of the three chemicals was tested by the Salmonella typhimurium reverse mutation test (Ames test) with TA97, TA98, TA100, and TA102 strains in the system with and without rat liver microsomal preparations (S9). The four tester strains have been used for more than 40 years to detect mutagenic compounds in chemicals, cosmetics, and environmental samples. The mutagenicity was detected on tester strains in the separated experiment from the three chemicals. The addition of S9 decreased the mutation ratios of toluene to four strains, except for the TA100 strain, but increased the mutation ratios of chloroform to four strains except for the TA98 strain. Trichloroethylene caused positive mutagenicity to become negative on the TA102 strain. In the mixed experiment, positive effects were detected only on the TA102 strain in the absence of S9. The addition of S9 increased the mutagenicity except for the TA102 strain. The mixture of toluene, chloroform, and trichloroethylene showed antagonism in mutagenicity to tester strains, except for the TA102 strain without S9. However, the mixture showed a synergistic effect to tester strains after adding S9 except for the TA98 strain.

Background Perillaldehyde and cinnamaldehyde are natural substances found in plants that are used as flavoring ingredients. Due to the α,β-unsaturated aldehydes in their structures, these compounds are expected to be DNA reactive. Indeed, several reports have indicated that perillaldehyde and cinnamaldehyde show positive in in vitro and in vivo genotoxicity tests. However, their genotoxic potentials are currently disputed. To clarify the mutagenicity of perillaldehyde and cinnamaldehyde, we conducted in silico quantitative structure–activity relationship (QSAR) analysis, in vitro Ames tests, and in vivo transgenic rodent gene mutation (TGR) assays. Results In Ames tests, perillaldehyde was negative and cinnamaldehyde was positive; these respective results were supported by QSAR analysis. In TGR assays, we treated Muta™ Mice with perillaldehyde and gpt-delta mice with cinnamaldehyde up to the maximum tested doses (1000 mg/kg/day). There was no increase in gene mutations in the liver, glandular stomach, or small intestine following all treatments except the positive control (N-ethyl-N-nitrosourea at 100 mg/kg/day). Conclusions These data clearly show no evidence of in vivo mutagenic potentials of perillaldehyde and cinnamaldehyde (administered up to 1000 mg/kg/day) in mice; however, cinnamaldehyde is mutagenic in vitro.

Kirkland et al. [Mutation Research/Genetic Toxicology and Environmental Mutagenesis 847 (2019) 403035, https://doi.org/10.1016/j.mrgentox.2019.03.008 ; Mutation Research/Genetic Toxicology and Environmental Mutagenesis 839 (2019): 21–35, https://doi.org/10.1016/j.mrgentox.2019.01.007 ] made recommendations on the use of the in vivo comet and transgenic rodent (TGR) gene mutation assays to screen for in vivo mutagenicity. Although it is not directly stated in either of these publications, we are concerned that the reports could potentially be used to support assertions that it is equally acceptable to follow up a positive bacterial reverse mutation (Ames) finding for an investigational drug with either the in vivo TGR mutation assay or an in vivo comet assay. For regulatory genotoxicity assessment, the in vivo follow-up for an in vitro bacterial mutation-positive drug, drug-related metabolite, or impurity should be based upon evaluating a similar endpoint (i.e., mutagenicity) as the intent is to determine if the findings of in vitro gene mutation correlate with findings of in vivo gene mutation (i.e., biologically relevant to the in vitro results). Thus, the most scientifically appropriate in vivo assays would be the TGR mutation assay or, in some circumstances, the in vivo Pig-a assay. An in vivo rodent comet assay or combination of the in vivo micronucleus and in vivo rodent comet assays would generally not be an appropriate follow-up test.

Chemical carcinogens to humans have been usually identified by epidemiological studies on the relationships between occupational or environmental exposure to the agents and specific cancer induction. In contrast, carcinogenic heterocyclic amines were identified under the principle that mutagens in bacterial in the Ames test are possible human carcinogens. In the 1970s to 1990s, more than 10 heterocyclic amines were isolated from pyrolysates of amino acids, proteins, meat or fish as mutagens in the Ames test, and they were demonstrated as carcinogens in rodents. In the 1980s and 1990s, we have developed derivatives of the Ames tester strains that overexpressed acetyltransferase of Salmonella typhimurium. These strains such as Salmonella typhimurium YG1024 exhibited a high sensitivity to the mutagenicity of the carcinogenic heterocyclic amines. Because of the high sensitivity, YG1024 and other YG strains were used for various purposes, e.g., identification of novel heterocyclic amines, mechanisms of metabolic activation, comparison of mutagenic potencies of various heterocyclic amines, and the co-mutagenic effects. In the 1990s and 2000s, we developed transgenic mice and rats for the detection of mutagenicity of chemicals in vivo. The transgenics were generated by the introduction of reporter genes for mutations into fertilized eggs of mice and rats. We named the transgenics as gpt delta because the gpt gene of Escherichia coli was used for detection of point mutations such as base substitutions and frameshifts and the red/gam genes of λ phage were employed to detect deletion mutations. The transgenic rodents gpt delta and other transgenics with lacI or lacZ as reporter genes have been utilized for characterization of mutagenicity of heterocyclic amines in vivo. In this review, we summarized the in vitro mutagenicity of heterocyclic amines in Salmonella typhimurium YG strains and the in vivo mutagenicity in transgenic rodents. We discussed the relationships between in vitro and in vivo mutagenicity of the heterocyclic amines and their relations to the carcinogenicity.

The present data described the analysis of mutagenicity in SynacinnTM by assessing the point mutations occurring due to Synacinn™ exposure to five tester strains of Salmonella typhimurium (TA1537, TA1535, TA98, TA100 and TA102), in the presence or absence of an exogenous mammalian metabolic activation system (S9). It was conducted in two Phases - Phase I (Dose Range Finding experiment-DRF) and Phase II (Mutagenicity Assay 1 and 2). DRF and Mutagenicity Assay 1 was conducted employing plate incorporation method, while Mutagenicity Assay 2 was performed using pre-incubation method. Formulation analysis pertaining to SynacinnTM was performed for both Mutagenicity Assay 1 and 2. Dose formulations were prepared fresh on each day of the experiment. Adventol 50% v/v in purified water was selected as a suitable vehicle based on the preliminary solubility test. Based on the Phase I analysis, 5 mg/plate was selected as the highest concentration of SynacinnTM followed by lower concentrations of 2.5, 1.25, 0.625 and 0.313 mg/plate for the Mutagenicity Assays. Genetic integrity of all the tester strains used was confirmed by performing genotyping before their use. All the data acceptability criteria were fulfilled confirming the validity of the test.

The aim of this paper was to investigate the relationship between micronuclei and DNA damage in children’s buccal mucosa cells and the genotoxicity and mutagenicity of the different sized fractions of particulate matter as well as the concentration of PAHs (polycyclic aromatic hydrocarbons) and metals in particulate matter. Air particulate matter was collected by high volume samplers located near the schools attended by the children on the same days of biological samplings. The mutagenic activity was assessed in different cells in in vitro tests (Ames test on bacteria and comet test on leukocytes). Our study showed weak positive correlations between (a) the mutagenicity of the PM0.5 fraction and PAHs and (b) the micronuclei test of children’s buccal cells and PAHs detected in PM0.5 and PM0.5–3 fractions. A positive correlation was also found between in vitro comet test on leukocytes and PAHs in the PM3–10 fraction. No correlation was observed for metal concentrations in each PM fraction.