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Genetic toxicology tests are used to categorize substances as genotoxic and potentially carcinogenic. In general, test results are designated as mutagenic, not mutagenic, or inconclusive and, depending on its potential use and applicable regulations, a mutagenic result can restrict or remove a substance from further development, or assign limits to its use. In these tests, mutation responses form a continuum without a clear delineation between an increase over the background, untreated, mutant frequency and a frequency that would define the test substance as a mutagen and a potential carcinogenic hazard. This situation is illustrated using the Salmonella mutagenicity (Ames) test which is the initial, and often only, test used to characterize substances as mutagenic or nonmutagenic. It has its widest use by industry and regulatory authorities to identify potential carcinogens among chemicals in development. The OECD Test Guideline No. 471 has been adopted by regulatory agencies internationally, and describes the minimum requirements for a negative response, but does not provide a specific approach for evaluating the test data. The most widely used criterion for making yes‐or‐no mutagenicity decisions is a 2‐ or 3‐fold increase over the background (solvent) mutant frequency. Other approaches rely on formal statistics and/or expert judgment. These approaches and recently proposed modifications are evaluated here. Recommendations are made that are in conformity with the OECD guideline and are based on biological relevance and the biology of the mutagenic response rather than on arbitrary decision points (e.g., ≥2‐fold increase or p ≤.05). [ABSTRACT FROM AUTHOR]

The European regulation REACh (Registration, Evaluation, Authorization, and restriction of Chemicals) has placed responsibility on the industry to manage the risk from chemicals since 2006. In order to ensure a high level of protection of human health and environment, toxicity prediction methods are now a widely used tool for regulatory decision making and selection of leads in new substances design. These in silico methods are an alternative to traditional in vitro and in vivo testing methods, which are laborious, time‐consuming, highly expensive, and even involve animal welfare issues. Many computational methods have been employed to predict the toxicity profile of substances, but they are mostly adapted to pharmaceutical molecules and not to High Energetic Materials (HEMs). In line with these restrictions, ArianeGroup set up a collaborative project with the French CNRS to develop optimized tools for the prediction of HEM properties, such as genotoxicity. Several in silico methods can be used to predict the properties of molecules, such as QSAR, Local QSAR or Machine Learning. We already demonstrated that using Local QSAR allows for better predictions with a good reliability [1]. We therefore developed a genotoxicity prediction tool based on the structural similarity search coupled with a supervised machine learning algorithm. This tool is composed of 3 predictive models: the Ames test, the Chromosomal Aberration test and the Mouse Lymphoma Assay. The aim of this paper is to evaluate the performance of these models to predict the genotoxicity of HEMs. We also present the methodology we applied to build these models and to optimize their performances. The dimensional reduction of the training set and the hyperparameters tuning of the different algorithms showed a performance acceleration and a significant reduction of the overfitting, which caused a decline in the generalization capacity of the predictive models. The performance of the predictive models was evaluated on a test set of HEMs and compared to the results of other prediction softwares. [ABSTRACT FROM AUTHOR]

Aflatoxin B1 (AFB1) is the most harmful mycotoxin commonly found in food and feed. Pollution from AFB1 causes serious economic and health issues worldwide because it causes strong mutagenicity and carcinogenicity in humans and animals. In this study, Pseudomonas aeruginosa was used to degrade AFB1 in moldy maize, and the safety of this biological method was investigated using genotoxicity and cytotoxicity tests. Using response surface methodology, we established the optimal conditions for degrading AFB1 by the fermentation supernatant of P. aeruginosa. Under these conditions, the degradation rate of AFB1 reached 99.67%. Furthermore, the Ames mutagenicity test showed that AFB1 treated with P. aeruginosa fermentation supernatant for 72 h was not mutagenic. CCK-8 cell assay showed that AFB1 cytotoxicity was significantly reduced after degradation. Overall, our findings show that the fermentation supernatant of P. aeruginosa may be a good candidate for biodegradation of AFB1. [ABSTRACT FROM AUTHOR]

Agri-food by-products represent a considerable portion of the waste produced in the world and especially when incorrectly disposed of, contribute to air, soil, and water pollution. Recently, recycling of food waste has proven to be an attractive area of research for pharmaceutical companies, that use agri-food by-products (leaves, bark, roots, seeds, second-best vegetables) as alternative raw material for the extraction of bioactive compounds. Developers and producers are however, advised to assess the safety of nutraceuticals obtained from biowaste that, in virtue of its chemical complexity, could undermine the overall safety of the final products. Here, in compliance with EFSA regulations, we use the Ames test (OECD 471) and the micronucleus test (OECD 487) to assess the mutagenicity of two nutraceuticals obtained from food waste. The first consists of grape seeds (Vitis vinifera L.) that have undergone a process of food-grade depolymerization of proanthocyanidins to release more bioavailable flavan-3-ols. The second nutraceutical product consists of thinned nectarines (Prunus persica L. var nucipersica) containing abscisic acid and polyphenols. The results presented here show that these products are, before as well as after metabolization, non-mutagenic, up to the doses of 5 mg and 100 μg per plate for the Ames and micronucleus test, respectively, and can be thus considered genotoxically safe. [ABSTRACT FROM AUTHOR]

The safety of food contact materials/articles (FCMs/FCAs) is an important issue, accentuated by these new regulations on the circularity of packaging and the end of single-use plastic packaging. It is therefore essential to develop protocols to ensure the safety of future packaging by identifying the unknown substances or by testing the toxicity of the complex mixture of substances migrating from FCMs/FCAs. Although Regulation 10/2011 on plastics is the only regulation that requires assurance of the health risk of NIAS, all packaging is affected by their presence, including bio-based, reusable and recycled materials, which will be increasingly present on the market in the context of the circular economy. Food packaging is made of four main materials, namely plastic, cardboard, glass and metals (aluminium and steel), as well as many other materials (wood, waxes, corks, etc.). [Extracted from the article]

Air pollutants include many compounds among them oxygenated polycyclic aromatic hydrocarbons (oxy‐PAHs). As they are suspected to generate DNA damage and mutagenicity, an understanding of their mode of action could highlight a carcinogenic potential risk in exposed population. In this article, a prospective study on seven oxy‐PAHs selected in terms of occurrence in the environment was conducted on mutagenicity, genotoxicity, and cytotoxicity potentials using in vitro assays including Ames test on five strains, kinetic analysis of cytotoxicity and apoptosis, phosphorylation of histone H2AX, and p53 induction assays on human lung cell line BEAS‐2B. Ames test demonstrated that mutagenicity pattern depended on the oxy‐PAH tested. Except for BAQ, all oxy‐PAHs tested gave mutagenic effect, in the absence and/or in the presence of metabolic activation (S9 fraction). At 24 h of exposure, the majority of oxy‐PAHs induced γ‐H2AX in BEAS‐2B cells and/or phosphorylation of p53 at serine 15 and cell death at highest tested concentrations. Although 9,10‐AQ and B[b]FO were mutagenic in bacteria, they failed to induce any of the other genotoxicity biomarkers. In comparison with the benzo[a]pyrene, all oxy‐PAHs were less potent in terms of genotoxic potential at the same concentration. These results highlighted the genotoxic and mutagenic potential of these oxy‐PAHs and provide preliminary information concerning their possible mechanism of action for toxicity, contributing to a better evaluation of the real associated health risks for human and environment. [ABSTRACT FROM AUTHOR]

Copyright of New Food Industry is the property of NFI LLC. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water kefir grains (WKGs), the starter used to develop a traditional beverage named water kefir, consist of a symbiotic mixture of probiotics with diverse bioactivities, but little is known about their abilities to remove mycotoxins that have serious adverse effects on humans and animals. This study investigated the ability of WKGs to remove aflatoxin B1 (AFB1), one of the most toxic mycotoxins, under different settings, and determined the mechanism of absorption mediated by WKGs and the effect of WKGs on the toxicity induced by AFB1 and the reduction in AFB1 in cow milk and tea soups. The results showed the WKGs used herein were dominated by Lactobacillus, Acetobacter, Phenylobacterium, Sediminibacterium, Saccharomyces, Issatchenkia, and Kodamaea. HPLC analysis demonstrated that the WKGs effectively removed AFB1 at concentrations ranging from 1 to 5 µg/mL, pH values ranging from 3 to 9, and temperatures ranging from 4 to 45 °C. Additionally, the removal of AFB1 mainly depended on absorption, which was consistent with the Freundlich and pseudo-second-order kinetic models. Moreover, only 49.63% of AFB1 was released from the AFB1-WKG complex after four washes when the release of AFB1 was non-detectable. Furthermore, WKG treatment caused a dramatic reduction in the mutagenicity induced by AFB1 according to an Ames test and reduced more than 54% of AFB1 in cow milk and three tea soups. These results suggested that WKGs can act as a potential bio-absorbent with a high binding ability to detoxify AFB1 in food and feed via a chemical action step and multi-binding sites of AFB1 absorption in a wide range of scenarios.

The Ames/quantitative structure–activity relationship (QSAR) International Challenge Projects, held during 2014–2017 and 2020–2022, evaluated the performance of various predictive models. Despite the significant insights gained, the rules allowing participants to select prediction targets introduced ambiguity in model performance evaluation. This reanalysis identified the highest-performing prediction model, assuming a 100% coverage rate (COV) for all prediction target compounds and an estimated performance variation due to changes in COV. All models from both projects were evaluated using balance accuracy (BA), the Matthews correlation coefficient (MCC), the F1 score (F1), and the first principal component (PC1). After normalizing the COV, a correlation analysis with these indicators was conducted, and the evaluation index for all prediction models in terms of the COV was estimated. In total, using 109 models, the model with the highest estimated BA (76.9) at 100% COV was MMI-VOTE1, as reported by Meiji Pharmaceutical University (MPU). The best models for MCC, F1, and PC1 were all MMI-STK1, also reported by MPU. All the models reported by MPU ranked in the top four. MMI-STK1 was estimated to have F1 scores of 59.2, 61.5, and 63.1 at COV levels of 90%, 60%, and 30%, respectively. These findings highlight the current state and potential of the Ames prediction technology.

Abstract Background Various natural color additives are preferred by many consumers over synthetic color additives because they are perceived to be safer. However, most do not have sufficient toxicity data for safety assurance. Color ingredients in particular have some structures suspected of being toxic. Eight natural color additives, gardenia red, blue, and yellow; lac color; cochineal extract; beet red; Curcuma longa Linne extract (Curcuma extract); and Monascus red, currently permitted for use in Korea, were selected and subjected to genotoxicity tests. Acceptable daily intake values have not been allocated to these color additives (except for cochineal extract) due to the lack of toxicity data. We used genotoxicity testing—the bacterial reverse mutation test (Ames test), in vitro mammalian chromosomal aberration test, and in vivo alkaline comet test—for minimum safety assurance. Results Gardenia red and blue, cochineal extract, lac color, and beet red did not induce mutagenicity or chromosomal abnormalities. Gardenia yellow was mutagenic in the Ames test, but was not positive in the in vitro chromosomal aberration test or in vivo alkaline comet assay. Curcuma extract and Monascus red induced cytotoxicity in the Ames test at high concentrations in Salmonella typhimurium TA1537 and TA100, without showing mutagenicity. On cytotoxicity testing, Curcuma extract and Monascus red showed cytotoxicity at concentrations higher than 313 μg/ml in Chinese hamster ovary CHO-K1 cells and showed equivocal results in chromosomal aberration assay of the same cells. Curcuma extract and Monascus red produced significant increases in DNA damage at a dose of 2000 mg/kg b.w./day, and induced dose-dependent increases in % DNA in the tail and tail moment on in vivo comet assay. Conclusions Six out of eight food colorants did not cause genotoxicity and cytotoxicity. However, Monascus red and Curcuma extract showed definite cytotoxicity and probable genotoxicity.

(1) Background: The aim of this study was to identify the degradation product of ramipril (RAM) formed under dry air and to verify its potential modes of carcinogenicity. We intended to check whether its formation and presence in final dosage forms could pose a cancer risk to humans who are treated with RAM due to cardiological indications. The carcinogenicity of this compound was evaluated with respect to two mechanisms: a potential direct DNA-damage and indirect toxicity, secondary to forming mutagenic N-nitroso metabolites. (2) Methods: Firstly, a forced ageing test under dry air was conducted for pure RAM in order to induce its degradation. The validated HPLC system was used to describe the kinetic order of this reaction. The emerging degradation impurity was identified by HPLC-MS. In the second stage, the cancer risk of the identified RAM degradant was predicted using a structure-based assessment by in silico QSAR model, employing three endpoints: carcinogenicity, genotoxicity and mutagenicity. In the third stage, the obtained QSAR results were experimentally verified. To verify genotoxicity prediction, in vitro micronucleus assay was employed. It enabled us to assess the potential direct DNA-damaging properties of RAM degradant at high concentrations (as screening series) and at concentrations usually observed in human blood (to mimic the clinical scenario). To verify the QSAR mutagenicity prediction, an in vitro Ames test was carried out. It was designed so as to detect two mechanisms of mutagenicity: a direct one (for pure degradant) and an indirect one (via N-nitroso-metabolites formation). N-nitroso-metabolites for mutagenicity assessment were obtained using NAP test. (3) Results: The kinetic mechanism of RAM degradation was first-order, the degradation rate constant was k = 1.396 ± 0.133 × 10−5 s−1 (T = 373 K), thus the formation of impurity was rapid. Energy of activation was 174.12 ± 46.2 kJ/mol, entropy was positive, thus reaction was bimolecular and favored; enthalpy was 171.65 ± 48.7 kJ/mol, thus reaction was endothermic. Only one degradation impurity was formed, and it was identified as RAM diketopiperazine derivative (DKP). QSAR simulation predicted that DKP could be carcinogenic and genotoxic, but this result had only moderate reliability. DKP was also predicted to be non-mutagenic and this prediction was strong (endpoint score 0.2). The confirmatory micronucleus experiment for genotoxicity prediction suggested that DKP was cytotoxic and it could be also aneugenic at a high concentration (0.22 mg/mL), evidenced by a three-fold increase in micronuclei relative to the control (11.86:33.33%, p = 0.0184). At physiologic concentrations, its cytotoxicity and genotoxicity did not occur. This means that the genotoxicity of DKP was limited by a threshold mechanism. In the mutagenicity in vitro assessment, pure DKP was not mutagenic, but its nitrosation product induced base substitutions mutations in test bacteria TA100 following metabolic activation at a concentration of 4.5 mg/mL, confirming its mutagenicity. (4) Conclusions: RAM rapidly cyclizes to diketopiperazine derivative under dry air. This impurity resides in drugs administered to patients. DKP is potentially aneugenic and cytotoxic at high concentrations, yet at concentrations typically occurring in human blood, this effect is unlikely. The exposure of patients to high concentrations of DKP, exceeding the typical blood level and standard RAM dosing, could lead to cancer development, thus the safe threshold for human exposure to DKP must be verified in follow-up in vivo experiments. Based on our results, it is impossible to establish the maximum safe dose of pure DKP to humans. Furthermore, DKP itself is not mutagenic, but it is liable to the formation of mutagenic nitroso-metabolites in vivo. Nitroso-derivatives of DKP are in vitro mutagens and their real-life impact on humans must be further evaluated in in vivo studies. Until this is carried out, RAM should not be formulated by manufacturers using dry procedures to minimize DKP formation and reduce risk of human carcinogenesis, since DKP could cause cancer via two independent mechanisms: direct genotoxicity when the exposure over standard RAM dosing occurs, and indirect mutagenicity via in vivo N-nitrosamine formation. [ABSTRACT FROM AUTHOR]

Drinking water quality can be compromised at different stages, from raw water to treated one. This research aimed to evaluate the toxicity and genotoxicity of groundwater contaminated by fluorinated compounds treated in a drinking water treatment plant, through several bioassays. Water samples underwent chemical analyses and were assayed on Daphnia magna, Pseudokirchneriella subcapitata, Allium cepa, human leukocytes and Salmonella typhimurium. Physical–chemical parameters were always within the Italian legislation limits. Water after filtration and disinfection caused slight toxicity in D. magna; the sample after filtration inhibited the proliferation of P. subcapitata. None of the water samples exerted toxicity in A. cepa. All the analysed samples had genotoxic effects on A. cepa and human leucocytes, while only disinfected water caused mutations in S. typhimurium. A battery composed of tests on D. magna, P. subcapitata, S. typhimurium and A. cepa could represent a useful tool to verify the toxicity/genotoxicity through the water treatment stages and to improve drinking water quality management. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Toxicity evaluation of main zopiclone impurities can provide a basis for safety assessment and quality standards of zopiclone. In this study, the impurity profile of zopiclone was analyzed using forced degradation and related substances of zopiclone tablets using high‐performance liquid chromatography (HPLC). Furthermore, various quantitative structure–activity relationship (QSAR) models were used to compare the toxicity, especially genotoxicity of two main zopiclone degradation impurities, namely, impurity B and 2‐amino‐5‐chloropyridine. The predictive genotoxicity results were verified using an in vitro bacterial reverse mutation (Ames) test. Meanwhile, using zebrafish embryos as an animal model, zopiclone and its main impurities were analyzed at different concentrations, and their effects on zebrafish development, including embryonic teratogenesis and lethality, were examined. The results showed that impurity B and 2‐amino‐5‐chloropyridine were the main degradation impurities of zopiclone; the latter's content increased with increase in the solution storage time. QSAR prediction and in vitro test results confirmed that both impurity B and 2‐amino‐5‐chloropyridine were non‐mutagenic and classified in the fifth impurity category. According to ICH M7 guidelines, these could be controlled as general non‐mutagenic impurities. The relative toxicity to zebrafish embryo development was the highest for 2‐amino‐5‐chloropyridine, followed by impurity B and zopiclone, and the malformation rate and mortality of embryos were concentration dependent. In conclusion, an increase in the control limit of 2‐amino‐5‐chloropyridine is recommended when the quality standards of zopiclone materials and preparations are revised to ensure safety and quality control. The specific limit value of this impurity should be determined through further evaluation and research. The toxicity of two main degradation impurities, zopiclone impurity B and 2‐amino‐5‐chloropyridine, was evaluated based on quantitative structure–activity relationship models and an in vitro bacterial reverse mutation test. Both impurities could be controlled as general non‐mutagenic impurities. The relative toxicity to zebrafish embryo development was the highest for the 2‐amino‐5‐chloropyridine, followed by impurity B and zopiclone. It is recommended to increase the control limit of 2‐amino‐5‐chloropyridine when the quality standards of zopiclone raw materials and preparations are revised. [ABSTRACT FROM AUTHOR]

Background: Transplantation of differentiated cells from human-induced pluripotent stem cells (hiPSCs) holds great promise for clinical treatments. Eliminating the risk factor of malignant cell transformation is essential for ensuring the safety of such cells. This study was aimed at assessing and mitigating mutagenicity that may arise during the cell culture process in the protocol of pancreatic islet cell (iPIC) differentiation from hiPSCs. Methods: We evaluated the mutagenicity of differentiation factors used for hiPSC-derived pancreatic islet-like cells (iPICs). We employed Ames mutagenicity assay, flow cytometry analysis, immunostaining, time-resolved fluorescence resonance energy transfer-based (TR-FRET) cell-free dose–response assays, single-cell RNA-sequencing and in vivo efficacy study. Results: We observed a mutagenic effect of activin receptor-like kinase 5 inhibitor II (ALK5iII). ALK5iII is a widely used β-cell inducer but no other tested ALK5 inhibitors induced β-cells. We obtained kinase inhibition profiles and found that only ALK5iII inhibited cyclin-dependent kinases 8 and 19 (CDK8/19) among all ALK5 inhibitors tested. Consistently, CDK8/19 inhibitors efficiently induced β-cells in the absence of ALK5iII. A combination treatment with non-mutagenic ALK5 inhibitor SB431542 and CDK8/19 inhibitor senexin B afforded generation of iPICs with in vitro cellular composition and in vivo efficacy comparable to those observed with ALK5iII. Conclusion: Our findings suggest a new risk mitigation approach for cell therapy and advance our understanding of the β-cell differentiation mechanism. [ABSTRACT FROM AUTHOR]

Herbal remedies used in traditional medicine often contain several compounds combined in order to potentiate their own intrinsic properties. However, herbs can sometimes cause serious health troubles. In Belgium, patients who developed severe aristolochic acid nephropathy ingested slimming pills containing root extracts of an Aristolochia species, as well as the bark of Magnolia officinalis. The goal of the study was to evaluate, on a human renal cell line, Aristolochia and Magnolia extracts for their cytotoxicity by a resazurin cell viability assay, and their genotoxicity by immunodetection and quantification of the phosphorylated histone γ-H2AX. The present study also sought to assess the mutagenicity of these extracts, employing an OECD recognized test, the Ames test, using four Salmonella typhimurium strains with and without a microsomial fraction. Based on our results, it has been demonstrated that the Aristolochia–Magnolia combination (aqueous extracts) was more genotoxic to human kidney cells, and that this combination (aqueous and methanolic extracts) was more cytotoxic to human kidney cells after 24 and 48 h. Interestingly, it has also been shown that the Aristolochia–Magnolia combination (aqueous extracts) was mutagenic with a TA98 Salmonella typhimurium strain in the presence of a microsomial liver S9 fraction. This mutagenic effect appears to be dose-dependent. [ABSTRACT FROM AUTHOR]

Hesperetin glucosides such as hesperidin and hesperetin-7-glucoside are abundantly present in citrus fruits and have various pharmacological properties. However, the potential toxicity of hesperetin glucosides remains unclear. An initial assessment of the safety of hesperetin-7-glucoside–β-cyclodextrin inclusion complex (HPTGCD) as a functional food ingredient was undertaken to assess toxicity and mutagenic potential. A bacterial reverse mutation assay (Ames test) using Salmonella typhimurium (strains TA98, TA1535, TA100, and TA1537) and Escherichia coli (strain WP2 uvrA) with HPTGCD (up to 5000 µg/plate) in the absence and presence of metabolic activation was negative. In a single oral (gavage) toxicity study in male and female rats, HPTGCD at dose up to 2000 mg/kg did not produce mortality nor clinical signs of toxicity or change in body weight. In a subchronic oral (dietary admix) toxicity study in rats receiving 0, 1.5, 3, and 5% HPTGCD for 13 weeks, no adverse effects were noted and the no-observed-adverse-effect level (NOAEL) was 5% in the diet (equivalent to 3267.7 mg/kg/day for males and to 3652.4 mg/kg/day for females). These results provide initial evidence of the safety of HPTGCD. [ABSTRACT FROM AUTHOR]

Lacticaseibacillus paracasei strain PS23 (PS23) exhibits some probiotic properties. In this study, a genomic analysis of PS23 revealed no genes related to virulence or antibiotic resistance. Moreover, ornithine decarboxylase activity was not detected in vitro. In addition, PS23 was sensitive to the tested antibiotics. Genotoxicity tests for PS23 including the Ames test and chromosomal aberrations in vitro using Chinese hamster ovary cells and micronuclei in immature erythrocytes of ICR mice were all negative. Moreover, following a 28-day study involving repeated oral dose toxicity tests (40, 400, and 4000 mg/kg equal 1.28 × 1010, 1.28 × 1011, and 1.28 × 1012 CFU/kg body weight, respectively) using an ICR mouse model, no adverse effects were observed from any doses. In addition, supplementation with live or heat-killed PS23 ameliorates DSS-induced colonic inflammation in mice. Our findings suggest that PS23 is safe and has anti-inflammatory effects and may therefore have therapeutic implications. [ABSTRACT FROM AUTHOR]

This account describes the origins of our extensive investigations into the mutagenicity of N -acyloxy- N -alkoxyamides. Since their discovery as biologically active anomeric amides that mutate DNA in the Ames reverse mutation assay without the need for metabolic activation, we have used activities in the Ames test to understand the impact of structural variation on cellular access to, binding to and reactivity with DNA. We have developed an understanding of the roles played by hydrophobicity, electrophilic reactivity, steric effects and, importantly, intercalation on mutagenicity levels and therefore interactions with DNA. The evolution and application of meaningful quantitative structure–activity relationships is described, and examples of their utility in explaining molecule–DNA interactions are given. Their ability to explain previous mutagenicity data and, importantly, to predict meaningful mutagenic behaviour is also demonstrated. N -Acyloxy- N -alkoxyamides are direct-acting mutagenic anomeric amides that react with DNA. Mutagenic activities reflect how structural elements impact on this interaction with DNA. Reliable QSARs (quantitative structure–activity relationships) reveal how hydrophobicity, reactivity and steric factors affect mutagenic activity and can discern intercalative ability of polycyclic aromatics, with good predictive ability. [ABSTRACT FROM AUTHOR]

It is generally assumed that French fries are likely to have weak in vitro mutagenic activity, but most studies thereof have only assessed gene mutations. In this article, the genotoxicity of 10 extracts of French fries was assessed using the in vitro micronucleus test (following the principles of the OECD 487 guidelines). Each sample was obtained from a different mass catering company in Navarra (Spain). This assay, together with the Ames test, is recommended in the basic in vitro phase included in the European Food Safety Authority Opinion on Genotoxicity Testing Strategies Applicable to Food and Feed Safety Assessment. Eight of 10 samples from mass catering companies induced chromosomal aberrations in the in vitro micronucleus test. Moreover, French fries deep-fried in the laboratory for different periods of time (0, 3, 5, 10, 20, 30 min) were assessed using the in vitro micronucleus test. Genotoxicity was observed in all time periods from 3 min on. The biological relevance of these results must be further explored. [ABSTRACT FROM AUTHOR]

The current study aimed to investigate the phenolic and flavonoid contents, cytotoxicity, genotoxicity, and mutagenicity of ethanolic and aqueous extracts of A. roseum (Camb.). The MTT assay was used to determine cytotoxicity, Comet assay was used to determine genotoxicity and mutagenicity of extracts was assessed through Ames test. The results showed that total phenolic contents were higher in aqueous extract (538.26 mg GAE/100 g); however, total flavonoid contents were significantly higher in ethanolic extract (6553.29 mg Eq. of Quercetin/100 g). The cells survival percentage was significantly (P <.05) decreased as concentrations of ethanolic extract increased. However, no significant toxicity was observed in groups treated with 0.031–0.25 mg/ml of ethanolic extract of A. roseum compared to negative control (P >.05). IC50 of ethanolic and aqueous extract of A. roseum was 5.54 mg/ml and 11.39 mg/ml, respectively. The results indicated that all concentration groups of ethanolic and aqueous extract of A. roseum significantly (P <.05) lowered DNA damage than positive control group. The lowest DNA damage was observed at 0.031 and 0.062 mg/ml in both aqueous and ethanolic extracts. Moreover, at higher concentrations of 4, 8, and 16 mg/ml of both ethanolic and aqueous extract observed 100% DNA damage cells (comet cells). Moreover, Ames mutagenicity showed that no significant (P >.05) changes were observed in revertant colonies of both bacterial strains (T 98; T 100) at 0.25, 0.5, and 1 mg/ml concentrations of both aqueous and ethanolic extract of A. roseum as MI index was less than 2. The research concluded that A. roseum extracts exhibited no cytotoxicity, genotoxicity, and mutagenicity at lower concentrations (≤2 mg/ml). [ABSTRACT FROM AUTHOR]

Dried leaves of Lannea velutina A. Rich. and Sorindeia juglandifolia (A. Rich.) Planch. ex Oliv. (family Anacardiaceae) are used in African traditional medicine. Although these medicinal plants have widespread use in the treatment of inflammatory diseases, there is no scientific data concerning their preclinical or clinical safety. This work aimed to investigate the phytochemical properties of the leaves of both species using HPLC-UV/DAD, as well as the in vivo oral repeated-dose toxicity of 70% hydroethanolic leaf extract of S. juglandifolia and the in vitro genotoxicity of 70% hydroethanolic leaf extracts of L. velutina and S. juglandifolia. Clinical signs of toxicity, body weight variations, and changes in food consumption, mortality, and blood biochemical parameters were monitored. Genotoxicity was assessed using the bacterial reverse mutation assay (Ames test) with and without metabolic activation, according to OECD guidelines. The obtained results showed the presence of gallic acid and anacardic acid as the main marker constituents in both species. No significant changes in general body weight or food intake were observed; small significant changes with no critical relevance were observed in the blood biochemistry of animals treated with S. juglandifolia hydroethanolic extract (50, 400, and 1000 mg/kg body weight) compared to those in the control group. No genotoxicity was observed in the bacterial reverse mutation assay with S. juglandifolia and L. velutina extracts (up to 5 mg/plate). The safety data obtained in vivo and lack of genotoxic potential in vitro points to the safe medicinal use of S. juglandifolia and L. velutina extracts. [ABSTRACT FROM AUTHOR]

3‐Chloroallyl alcohol (3‐CAA) can be found in the environment following the application of plant protection products. 3‐CAA is formed in groundwater following the injection of 1,3‐dichloropropene, a fumigant used to control nematodes. 3‐CAA is also formed, in leafy crops, as a glycoside conjugate following application of the herbicide, clethodim. Human exposure may occur from groundwater used as drinking water or through dietary consumption. To characterize 3‐CAA's potential to cause genotoxicity in mammals, in vitro and in vivo studies were conducted. 3‐CAA was negative in an Ames test and positive in a mouse lymphoma forward mutation assay. 3‐CAA was negative in an acute in vivo CD‐1 mouse bone marrow micronucleus assay when administered up to a dose level of 125 mg/kg/day for two consecutive days. In a combined gene mutation assay and erythrocyte micronucleus assay, using transgenic Big Blue® Fischer 344 rats, 3‐CAA was administered via drinking water at targeted dose levels of 0, 10, 30, and 100 mg/kg/day for 29 days. Peripheral blood samples, collected at the end of treatment, were analyzed for micronucleus induction in reticulocytes using flow cytometry. Liver and bone marrow samples, collected 2 days after the termination of the treatment, were analyzed for the induction of mutations at the cII locus. 3‐CAA did not induce an increase in mutant frequency or micronuclei under the experimental conditions. In conclusion, the mutagenic response observed in the in vitro mouse lymphoma assay is not confirmed in the whole animal. 3‐CAA is not considered to pose a mutagenic risk. [ABSTRACT FROM AUTHOR]

Laboratory courses should cultivate enthusiasm for research and an appreciation for real‐world scientific challenges to retain undergraduate students and encourage them to pursue STEM‐related careers. Course‐based undergraduate research experiences (CURE) have emerged as an inclusive pedagogical model that facilitates laboratory skill development, while also improving self‐efficacy and critical thinking skills. Herein, an innovative research‐inspired Ames test for mutagenicity project is described. Students choose their own project theme and investigate substances using both TA98 and TA100 strains of Salmonella typhimurium to evaluate the potential for frameshift mutations and base‐pair substitutions, respectively. An appropriate test concentration of each substance is first determined via a cytotoxicity assay, providing an additional learning opportunity. Students also study the mutagenicity of test substance metabolites using commercially available rat liver extracts to simulate metabolism. Overall, these experiences provide a comprehensive research project with high relevancy to human health and real‐world importance. This laboratory module was assessed using CURE pre‐ and post‐course surveys to evaluate learning gains and benefits. Assessment data illustrated that students appreciated the discovery aspect of the research project and gained skills related to reading scientific literature and effective poster presentations. Student‐reported benefits of research project participation included learning new laboratory techniques, enhanced scientific writing skills, an increased tolerance for and understanding of common research challenges, and the confidence to tackle more complex research endeavors. Narrative feedback from students was very positive, with project highlights being the opportunity to select their own test substances and create new knowledge, as well as the analysis of results. [ABSTRACT FROM AUTHOR]

Background: The paucity of SARS-CoV-2-specific virulence factors has greatly hampered the therapeutic management of patients with COVID-19 disease. Although available vaccines and approved therapies have shown tremendous benefits, the continuous emergence of new variants of SARS-CoV-2 and side effects of existing treatments continue to challenge therapy, necessitating the development of a novel effective therapy. We have previously shown that our developed novel single-stranded DNA aptamers not only target the trimer S protein of SARS-CoV-2, but also block the interaction between ACE2 receptors and trimer S protein of Wuhan origin, Delta, Delta plus, Alpha, Lambda, Mu, and Omicron variants of SARS-CoV-2. We herein performed in vivo experiments that administer the aptamer to the lungs by intubation as well as in vitro studies utilizing PBMCs to prove the efficacy and safety of our most effective aptamer, AYA2012004_L. Methods: In vivo studies were conducted in transgenic mice expressing human ACE2 (K18hACE2), C57BL/6J, and Balb/cJ. Flow cytometry was used to check S-protein expressing pseudo-virus-like particles (VLP) uptake by the lung cells and test the immuogenicity of AYA2012004_L. Ames test was used to assess mutagenicity of AYA2012004_L. RT-PCR and histopathology were used to determine the biodistribution and toxicity of AYA2012004_L in vital organs of mice. Results: We measured the in vivo uptake of VLPs by lung cells by detecting GFP signal using flow cytometry. AYA2012004_L specifically neutralized VLP uptake and also showed no inflammatory response in mice lungs. In addition, AYA2012004_L did not induce inflammatory response in the lungs of Th1 and Th2 mouse models as well as human PBMCs. AYA2012004_L was detectable in mice lungs and noticeable in insignificant amounts in other vital organs. Accumulation of AYA2012004_L in organs decreased over time. AYA2012004_L did not induce degenerative signs in tissues as seen by histopathology and did not cause changes in the body weight of mice. Ames test also certified that AYA2012004_L is non-mutagenic and proved it to be safe for in vivo studies. Conclusions: Our aptamer is safe, effective, and can neutralize the uptake of VLPs by lung cells when administered locally suggesting that it can be used as a potential therapeutic agent for COVID-19 management. [ABSTRACT FROM AUTHOR]

Two series of nicotinonitrile and/or arene-linked bis(thiazoles) possessing chromene units are efficiently prepared in this study. A one-pot protocol was designed to prepare the target hybrids involved in the reaction of the respective salicylaldehydes, 2-cyanoethanethioamide, and the appropriate bis(α-haloketone). The reaction was irradiated by microwaves at 100 °C for 40–90 min in dioxane and mediated by piperazine to produce the desired products in 84–95% yields. Nicotinonitrile-linked hybrids 2b, and 2c attached to 6-(4-chlorophenyl) or 6-(4-nitrophenyl) units, respectively, had the best antibacterial activity, particularly against Staphylococcus aureus, and Enterococcus faecalis strains. They showed equipotent efficacy to ciprofloxacin with MIC/MBC values in the ranges from 5.9 to 12.0 µM. Additionally, 2c demonstrated comparable inhibitory activity to linezolid against MRSA and VRE strains with MIC/MBC values ranging from 2.9 to 11.8 µM. The Ames mutagenicity test was used to conclude that 2c was not mutagenic to the Salmonella strains. [ABSTRACT FROM AUTHOR]

Direct interference with Kelch-like ECH-associated protein 1 (Keap1)-Nrf2 protein-protein interaction (PPI) has recently been introduced as an attractive approach to control life-threatening diseases like myocarditis. The present study aimed to investigate the potential application in myocarditis of a series of novel non-naphthalene derivatives as potential Keap1-Nrf2 PPI inhibitors. Our results indicated that the optimal compound K22 displayed the highest metabolic stability and showed notable Keap1-Nrf2 PPI inhibitory activities in vitro. K22 effectively triggered Nrf2 activation and increased the protein and mRNA expression of Nrf2-regulated genes in H9c2 cells. Moreover, pre-treatment with K22 was shown to mitigate LPS-induced damage to H9c2 cells, causing a marked decrease in the levels of inflammatory factors as well as reactive oxygen species (ROS). Furthermore, K22 was also shown to be non-mutagenic in the Ames test. Overall, our findings suggest that K22 may be a promising drug lead as a Keap1-Nrf2 PPI inhibitor for myocarditis treatment. [ABSTRACT FROM AUTHOR]

Benzoxazoles are heterocyclic compounds containing fused benzene and oxazole rings, which have been reported to possess antibacterial, antitubercular, antifungal, antiviral, antioxidant and anticancer activities. In this study, the mutagenic properties of fifteen benzoxazole derivatives reported previously to exhibit broad antimicrobial and potent antitumor effects were investigated for their genotoxic potential by employing the Ames test. The Ames test was conducted using Salmonella typhimurium TA98, TA100 and TA102 tester strains in the standard plate incorporation assay with and without liver S9 fraction. The results were evaluated statistically and no mutagenic activity of test drugs was observed. Relationship between the structure and cytotoxic activity of compounds was evaluated using the SAR method based on data obtained via the Ames test system. [ABSTRACT FROM AUTHOR]

Abstract Background The use of medicinal plants in curing diseases is an ancient culture still in use in many parts of the world. Many plants have been proven to have precise ethno-pharmacological relevance. On the contrary, many folkloric plants have also been found to possess DNA damaging effects. Hence, assessing the safety profile of medicinal herbs before being approved for use must be undertaken. Main text This review focuses on medicinal plants exerting genotoxicity effect within through in vivo studies on the bone marrow, erythrocyte or other organs on animal models and in vitro studies on bacterial cells or mammalian cell lines such as mammalian lymphocytes, human hepatoma cell line or HepG2, mouse lung fibroblast cell lines or human adenocarcinoma cell lines. This review has found that several medicinal plants possess genotoxic potentials and are not safe to use. The common methodologies several authors have used include the comet assay, micronucleus assay, bacterial reverse mutation assay, Ames test or Salmonella/microsome assay. Conclusion Plants that have been proven to be genotoxic are not reduced to a particular family, while groups including Fabaceae, Asteraceae, Euphorbiaceae, Rosaceae, Lamiaceae and Apocynaceae appear to be frequent. To avoid any mutation in its users, genotoxicity assessment of therapeutic plants appears to be required.

Accurately determining the mutagenicity of small-molecule N -nitrosamine drug impurities and nitrosamine drug substance-related impurities (NDSRIs) is critical to identifying mutagenic and cancer hazards. In the current study we have evaluated several approaches for enhancing assay sensitivity for evaluating the mutagenicity of N -nitrosamines in the bacterial reverse mutagenicity (Ames) test. Preincubation assays were conducted using five activation conditions: no exogenous metabolic activation and metabolic activation mixes employing both 10% and 30% liver S9 from hamsters and rats pretreated with inducers of enzymatic activity. In addition, preincubations were conducted for both 60 min and 30 min. These test variables were evaluated by testing 12 small-molecule N -nitrosamines and 17 NDSRIs for mutagenicity in Salmonella typhimurium tester strains TA98, TA100, TA1535, and TA1537, and Escherichia coli strain WP2 uvrA (pKM101). Eighteen of the 29 N -nitrosamine test substances tested positive under one or more of the testing conditions and all 18 positives could be detected by using tester strains TA1535 and WP2 uvrA (pKM101), preincubations of 30 min, and S9 mixes containing 30% hamster liver S9. In general, the conditions under which NDSRIs were mutagenic were similar to those found for small-molecule N -nitrosamines. • 12 small molecule nitrosamines and 17 NDSRIs were assessed for mutagenicity in the Ames test. • A combination of TA1535 and WP2 uvrA(pKM101) was able to detect all mutagenic nitrosamines. • In general, preincubations with 30% S9 produced higher mutagenic responses than 10% S9. • In general, hamster liver S9 produced higher mutagenic responses than rat liver S9. • Factors affecting assay sensitivity were similar for NDSRIs and small molecule nitrosamines. [ABSTRACT FROM AUTHOR]

The natural vanilla market, which generates millions annually, is predominantly dependent on Vanilla planifolia , a species characterized by low genetic variability and susceptibility to pathogens. There is an increasing demand for natural vanilla, prized for its complex, authentic, and superior quality compared to artificial counterparts. Therefore, there is a necessity for innovative production alternatives to ensure a consistent and stable supply of vanilla flavors. In this context, vanilla crop wild relatives (WRs) emerge as promising natural sources of the spice. However, these novel species must undergo toxicity assessments to evaluate potential risks and ensure safety for consumption. This study aimed to assess the non-mutagenic and non-carcinogenic properties of ethanolic extracts from V. bahiana , V. chamissonis , V. cribbiana , and V. planifolia through integrated metabolomic profiling, in vitro toxicity assays, and in silico analyses. The integrated approach of metabolomics, in vitro assays, and in silico analyses has highlighted the need for further safety assessments of Vanilla cribbiana ethanolic extract. While the extracts of V. bahiana, V. chamissonis, and V. planifolia generally demonstrated non-mutagenic properties in the Ames assay, V. cribbiana exhibited mutagenicity at high concentrations (5000 μg/plate) in the TA98 strain without metabolic activation. This finding, coupled with the dose-dependent cytotoxicity observed in WST-1 (Water Soluble Tetrazolium) assays, a colorimetric method that assesses the viability of cells exposed to a test substance, underscores the importance of concentration in the safety evaluation of these extracts. Kaempferol and pyrogallol, identified with higher intensity in V. cribbiana , are potential candidates for in vitro mutagenicity. Although the results are not conclusive, they suggest the safety of these extracts at low concentrations. This study emphasizes the value of an integrated approach in providing a nuanced understanding of the safety profiles of natural products, advocating for cautious use and further research into V. cribbiana mutagenicity. • V. cribbiana extract shows mutagenicity at 5000 μg/plate. • Indication of kaempferol and pyrogallol link to V. cribbiana mutagenicity. • Safety of low-concentration vanilla extracts indicated. • WST-1 assays reveal dose-dependent cytotoxicity. • Study advocates cautious use of V. cribbiana and further analysis. [ABSTRACT FROM AUTHOR]

Laccase mediators possess advantage of oxidizing substrates with high redox potentials, such as aflatoxin B 1 (AFB 1). High costs of chemically synthesized mediators limit laccase industrial application. In this study, thin stillage extract (TSE), a byproduct of corn-based ethanol fermentation was investigated as the potential natural mediator of laccases. Ferulic acid, p -coumaric acid, and vanillic acid were identified as the predominant phenolic compounds of TSE. With the assistance of 0.05 mM TSE, AFB 1 degradation activity of novel laccase Glac1 increased by 17 times. The promoting efficiency of TSE was similar to ferulic acid, but superior to vanillic acid and p- coumaric acid, with 1.2- and 1.3-fold increases, respectively. After Glac1-TSE treatment, two oxidation products were identified. Ames test showed AFB 1 degradation products lost mutagenicity. Meanwhile, TSE also showed 1.3–3.0 times promoting effect on laccase degradation activity in cereal flours. Collectively, a safe and highly efficient natural mediator was obtained for aflatoxin detoxification. [Display omitted] • Thin stillage extract (TSE) is a cost-saving, efficient and natural laccase mediator. • Dominant phenolic acids of TSE are ferulic acid, p -coumaric acid and vanillic acid. • A novel Glac1 is a high sensitive laccase to mediator TSE on AFB 1 degradation. • Glac1-TSE possessed high activity on AFB 1 detoxification in cereal flours. [ABSTRACT FROM AUTHOR]

[Display omitted] • Compound 12 exhibited potent BRD4 inhibitory activity. • Compound 12 was found negative in the Ames test. • Compound 12 exhibited a favorable pharmacokinetic profile. • Compound 12 exhibited significant tumor growth inhibition in a mouse melanoma xenograft model. The bromodomain-containing protein 4 (BRD4), which is a key epigenetic regulator in cancer, has emerged as an attractive target for the treatment of melanoma. In this study, we investigate 7-phenoxy-benzimidazole derivative 12 , which is a novel BRD4 inhibitor for the treatment of melanoma, by performing scaffold hopping on the previously reported benzimidazole derivative 1. Despite their good oral and intravenous exposure, the compounds obtained by modifying derivate 1 exhibit mutagenicity, which was confirmed by the positive Ames test results. Based on our hypothesis that the cause of the Ames test positivity is the metabolic intermediates generated from those chemical series, we implemented a scaffold hopping strategy to avoid the N- benzyl moiety by relocating the substituent groups to preserve the essential interaction. Based on this strategy, we successfully obtained compound 12 ; the Ames test results of this compound were negative. Notably, compound 12 not only exhibited a favorable pharmacokinetic (PK) profile but also significant tumor growth inhibition in a mouse melanoma xenograft model, indicating its potential as a therapeutic agent for the treatment of melanoma. [ABSTRACT FROM AUTHOR]

In the present study, the effects of levamlodipine benzenesulfonate on the development of fertile Sprague-Dawley (SD) rats, their embryos, and littermates were assessed using an embryo-fetal developmental toxicity test. Maternal body weight reduction was observed at a dose of 20 mg/kg, but it recovered after treatment cessation. The 20 mg/kg dose group showed a skewed sex ratio in fetal rats, with a higher proportion of males. While some effects on fetal sternum development were observed at 20 mg/kg, no skeletal malformations were observed. No significant gross morphological abnormalities were detected in the dams (mothers), no significant embryotoxicity or foetotoxicity in fetal rats and no significant effects on fetal length and weight development at doses of 5 and 10 mg/kg. Genotoxicity was evaluated using a combination of the Ames test, the Chinese hamster ovary (CHO) cell chromosome aberration assay, and the ICR mouse bone marrow micronucleus test. The Ames test results indicated substantial bacteriostatic effects at doses of 500 and 5000 mg/dish, with no mutagenicity observed at doses of 0.5, 5, and 50 mg/dish. No significant effect on the aberration rate of CHO cell chromosomes was found at doses of 2.8, 5.6, and 11.2 mg/mL. In the ICR mouse micronucleus test, no micronucleus-inducing effect was observed at doses of 3.125, 6.25, and 12.5 mg/kg in each treatment group. In conclusion, under the conditions of this experiment, the no-observed-adverse-effect level (NOAEL) for developmental toxicity of levamlodipine benzenesulfonate in fertile SD rats, their embryos, and littermates was established to be 10 mg/kg/day. Levamlodipine benzenesulfonate did not exhibit significant genotoxicity. • First evaluation of the embryo-fetal developmental toxicity of levamlodipine benzenesulfonate compound I in SD rats. • The genotoxicity of levamlodipine benzenesulfonate compound I was evaluated for the first time. • The NOAEL of levamlodipine benzenesulfonate compound I in pregnant SD rats, embryos and fetuses was higher than 10 mg/kg/day. [ABSTRACT FROM AUTHOR]

Carpobrotus edulis (L.) N.E.Br. is an edible halophyte native to South Africa, where it has been traditionally consumed as food, revealing its nutritional value, and used in the treatment of human diseases probably due to the accumulation of bioactive compounds such as polyphenols. These compounds have potential to display valuable biological activities that could bring several benefits to the human being, including the mitigation of toxicity induced by food contaminants. Therefore, this study investigated biological activities with health-promoting potential of a C. edulis ethanol extract (CEE), such as antioxidant, antigenotoxic, and antimutagenic. CEE was shown by LC-DAD-ESI/MSn to be composed of 16 polyphenols. The extract exhibited antioxidant properties by protecting Saccharomyces cerevisiae viability and improving the redox state of HepG2 cells under oxidative stress. Antigenotoxicity of CEE against H 2 O 2 -induced oxidative damage was detected in HepG2 and Caco-2 cells by comet assay and subsequently observed in the dominant deletion assay in S. cerevisiae. Antigenotoxicity and antimutagenicity of CEE towards the neoformed contaminant benzo[a]pyrene was found in HepG2 and Caco-2 cells by comet assay and in Salmonella typhimurium using the Ames test, respectively. The disclosed antigenotoxic and antimutagenic properties of C. edulis further advance its potential for application in food and nutraceutical industries for health benefits. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cinnamamide derivatives possess potential to treat hyperpigmentation. • Cinnamamide derivative inhibited expression of melanogenesis-related genes. • Cinnamamide derivative inhibited melanogenesis in MelanoDerm. • Cinnamamide derivative showed beneficial safety profile in vitro. • (E)-3-(4-chlorophenyl)- N -(5-hydroxypentyl)acrylamide could be a cosmetic ingredient. Hyperpigmentation disorders may result from inappropriate melanin deposition and/or excessive melanin synthesis. They are classified mainly as aesthetic problems, but they can significantly affect human health by decreasing self-esteem. There are available only limited treatment options for hyperpigmentation disorder, among others, cosmetic products applied topically. Depigmenting ingredients were found to be ineffective and characterized by various side effects. As a result, many efforts are made to discover novel, potent, and safe melanogenesis inhibitors for possible use in topical cosmetic depigmenting formulations. Cinnamic acid derivatives constitute a widely tested group for that purpose. This article reports research in the group of N -alkyl cinnamamide derivatives (un)substituted in phenyl ring. Among tested series, (E)-3-(4-chlorophenyl)- N -(5-hydroxypentyl)acrylamide (compound 21) showed the most promising inhibitory properties in mushroom tyrosinase assay (IC 50 = 36.98 ± 1.07 µM for monophenolase activity, IC 50 = 146.71 ± 16.82 µM for diphenolase activity) and melanin production inhibition in B16F10 mouse melanoma cell line at concentration 6.25 µM resulting probably from decreasing of Tyr , Mitf, Tyrp-1 , and Tyrp-2 genes expression. This compound also showed melanin production inhibitory properties in pigmented reconstructed human epidermis when used in 1 % and 2 % solutions in 50 % PEG400. In vitro evaluation of its safety profile showed no cytotoxicity to human keratinocytes HaCaT, human skin fibroblasts BJ, and human primary epidermal melanocytes HEMa, no mutagenicity in the Ames test, no genotoxicity in micronucleus test, no phototoxicity, as well as no skin irritation potential tested in PEG400 solution. This compound was also shown to penetrate across the epidermis to reach the possible site of action. The performed research led to classify (E)-3-(4-chlorophenyl)- N -(5-hydroxypentyl)acrylamide as a novel potential depigmenting cosmetic ingredient. [ABSTRACT FROM AUTHOR]

The finding of N -nitrosodiethylamine (NDEA) and N -nitrosodimethylamine (NDMA) in marketed drugs has led to implementation of risk assessment processes intended to limit exposures to the entire class of N -nitrosamines. A critical component of the risk assessment process is establishing exposure limits that are protective of human health. One approach to establishing exposure limits for novel N -nitrosamines is to conduct an in vivo transgenic rodent (TGR) mutation study. Existing regulatory guidance on N -nitrosamines provides decision making criteria based on interpreting in vivo TGR mutation studies as an overall positive or negative. However, point of departure metrics, such as benchmark dose (BMD), can be used to define potency and provide an opportunity to establish relevant exposure limits. This can be achieved through relative potency comparison of novel N -nitrosamines with model N -nitrosamines possessing robust in vivo mutagenicity and carcinogenicity data. The current work adds to the dataset of model N -nitrosamines by providing in vivo TGR mutation data for N -nitrosopiperidine (NPIP). In vivo TGR mutation data was also generated for a novel N -nitrosamine impurity identified in sitagliptin-containing products, 7-nitroso-3-(trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo-[4,3-a]pyrazine (NTTP). Using the relative potency comparison approach, we have demonstrated the safety of NTTP exposures at or above levels of 1500 ng/day. • Practical strategies are needed to establish exposure limits for N -nitrosamines. • In vivo TGR mutation study provides compound specific data for novel N -nitrosamines. • Relative potency comparison of in vivo TGR data provides basis for exposure limit. • NPIP in vivo TGR data adds to the database of well-studied, model N -nitrosamines. • Relative potency comparison supports the safety of NTTP exposures ≥1500 ng/day. [ABSTRACT FROM AUTHOR]

Nitrosamine drug substance related impurities or NDSRIs can be formed if an active pharmaceutical ingredient (API) has an intrinsic secondary amine that can undergo nitrosation. This is a concern as 1) nitrosamines are potentially highly potent carcinogens, 2) secondary amines in API are common, and 3) NDSRIs that might form from such secondary amines will be of unknown carcinogenic potency. Approaches for evaluating NDSRIs include read across, quantum mechanical modeling of reactivity, in vitro mutation data, and transgenic in vivo mutation data. These approaches were used here to assess NDSRIs that could potentially form from the drugs fluoxetine, duloxetine and atomoxetine. Based on a read across informed by modeling of physicochemical properties and mechanistic activation from quantum mechanical modeling, NDSRIs of fluoxetine, duloxetine, and atomoxetine were 10-100-fold less potent compared with highly potent nitrosamines such as NDMA or NDEA. While the NDSRIs were all confirmed to be mutagenic in vitro (Ames assay) and in vivo (TGR) studies, the latter data indicated that the potency of the mutation response was ≥4400 ng/day for all compounds-an order of magnitude higher than published regulatory limits for these NDSRIs. The approaches described herein can be used qualitatively to better categorize NDSRIs with respect to potency and inform whether they are in the ICH M7 (R2) designated Cohort of Concern. • Based on modeling NDSRIs evaluated were 10-100-fold less potent when compared with potent nitrosamines such as NDMA or NDEA. • NDSRIs of fluoxetine, duloxetine and atomoxetine were confirmed to be mutagenic in vitro (Ames assay) and in vivo (TGR). • AI values for NDSRIs were >4400 ng/day based on TGR data, greater than current published regulatory limits. [ABSTRACT FROM AUTHOR]

The objective of the present study was to investigate some commonly detected halogenated textile pollutants for their bioavailability and hazardous properties. Release into artificial sweat and skin absorption in vitro were examined as well as mutagenic effects by Ames test, and skin-sensitizing properties from a peptide reactivity assay combined with a cell test. All investigated compounds were shown to migrate from the textile into sweat and be absorbed by the skin, although to a different extent. The experimental values for migration were found to be up to 390 times higher compared to literature values. Two of the studied compounds, 2,5-dinitrochlorobenzene and 3,5-dinitrobromobenzene, both exhibited mutagenic effects in the Ames test, while both 2,5-dinitrochlorobenzene and 2,6-dichlorobenzene-1,4-diamine were classified as skin sensitizers. The allergenic reactivity of the latter was found to be due to an oxidized transformation product. Risks for the induction of skin allergy and other non-carcinogenic effects from dermal exposure to the individual compounds were found low, even when considering clothing with the highest reported levels. However, the complex mixtures of chemicals often present in garments may still constitute a health risk, especially when considering the many hours of daily exposure. It is important to further study the toxicity of other frequently occurring chemicals as well as the synergistic effects of chemicals that co-occur in clothing. [Display omitted] • Skin allergenic and mutagenic halogenated pollutants occur frequently in synthetic garments. • Hazardous chemicals are able to migrate from the textile fibres into sweat and become bioavailable. • Dermal uptake of the individual compounds was found to constitute a low non-carcinogenic risk. [ABSTRACT FROM AUTHOR]

Pleural effusion, the pathological condition in which an abnormal amount of pleural fluid is accumulated in the small space between the visceral and parietal pleurae of the lungs, can be treated by pleurodesis, whereby the pleural space is obliterated. This effect can be achieved by chemical pleurodesis utilizing various reagents such as talc, an agent commonly employed in pleurodesis. Zeolites, microporous tectosilicates found in nature as minerals, can be used in a wide range of medical applications. Different zeolite compounds may exhibit variable efficacy and safety profiles, mainly depending on their particle size. In this study, we evaluated the efficacy and safety of zeolite pleurodesis. New Zealand rabbits were administered 400 mg/kg of either agent dissolved in 2 mL of isotonic saline solution by injection into their pleural cavity, and computed tomography images were obtained on postoperative day 26. Euthanization was conducted at the end of 28 days for histopathological evaluation. Furthermore, subacute toxicity and mutagenicity profiles of zeolite were analyzed. Our findings revealed that zeolite was able to induce an adequate inflammatory response to achieve successful pleurodesis. The adhesion profiles were in favor of zeolite when compared to talc pleurodesis. Moreover, none of the tested doses of zeolite induced subacute toxicity or mutagenesis. Collectively, our results suggested zeolite as an effective and safe pleurodesis agent.

Hydroxyanthracene derivatives are widely distributed in the plant kingdom, mainly in botanicals such as the Hypericum, Rheum, Rhamnus and Aloe genera. For centuries, plants containing hydroxyanthracene derivatives have been used as herbal remedies, mainly as laxatives. The root and underground stem (rhizome) are used to make medicine, primarily for digestive complaints including constipation, diarrhoea, heartburn, stomach pain, gastrointestinal bleeding, and preparation for certain gastrointestinal diagnostic procedures. The use of hydroxyanthracene-containing botanicals has raised the attention of European Food Safety Authority (EFSA) for the potential genotoxicity activity, that in 2018 concluded “[.] and that there is a safety concern for extracts containing hydroxyanthracene derivatives although uncertainty persists”. No genotoxic activity has been reported with other constituents such as rhein, physcion and chrysophanol. In the present study, Rhubarb ethanolic extract of ground rhubarb rhizome (hydroxyanthracene total content 1.39 %) was tested in the Ames Assay in Salmonella typhimurium and Escherichia coli, up to 5000 µg/plate and up to 5000 µg/mL in human lymphocytes Micronucleus Test (OECD 471 and 487 respectively) in vitro mutagenic and genotoxic effects. Under the experimental conditions used, the rhubarb rhizome extract showed no genotoxic activity.

We assessed the genotoxicity of 30 food-flavoring chemicals used in Japan that have not been investigated before. These 30 food-flavoring chemicals have representative chemical structures belonging to 18 chemical classes. The Ames and chromosomal aberration (CA) tests (in vitro tests) were first conducted in accordance with the “Food Additive Risk Assessment Guidelines” of the Japan Food Safety Commission. If the in vitro test yielded a positive result, an in vivo micronucleus test or a transgenic mouse gene mutation assay was performed to verify the in vitro test results. Of the 30 food-flavoring chemicals, 3 yielded a positive result in both Ames and CA tests. Another 11 chemicals yielded positive results in the CA test. However, none of the chemicals yielding positive in vitro test results yielded positive results in the in vivo tests. These findings indicate no genotoxicity concerns of the food-flavoring chemicals belonging to the abovementioned 18 chemical classes used in Japan unless there are other structural modifications.

Cellulose nanofibrils (CNFs) are identified as novel nanomaterials with many potential applications. Since CNFs are fibrous manufactured nanomaterials, their potential carcinogenic effects and mesothelial toxicity raise some concerns. In this study, we conducted a standard battery of in vitro and in vivo assays to evaluate the genotoxicity of two CNF types using different manufacturing methods and physicochemical properties. Namely, one was CNF produced via chemical modification by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation, while the other was CNF produced via mechanical defibrillation using needle bleached kraft pulp. A bacterial reverse mutation test and a mouse lymphoma TK assay revealed that CNFs at 100 μg/mL did not induce bacterial reverse mutations and in vitro mammalian cell gene mutation. Further, in vitro chromosomal aberration tests demonstrated that CNFs at 100 μg/mL did not induce chromosomal aberration in Chinese hamster lung fibroblasts. From the mammalian erythrocyte micronucleus test, no statistically significant increase was observed in the proportion of micronucleated polychromatic erythrocytes in the bone marrow cells of rats intratracheally instilled with any concentration of CNFs (0.25–1.0 mg/kg) compared with values from respective negative control groups. Therefore, this battery of in vitro and in vivo assays illustrated that the CNFs examined in this study did not induce genotoxicity, suggesting our results provide valuable insight on the future use of these materials in various industrial applications.

Abstract Background Py-mulin is a new pleuromutilin derivative with potent antibacterial activities in vitro and in vivo, suggesting this compound may lead to a promising antibacterial drug after further development. The present study is aimed to evaluate the acute and subacute oral toxicity, and the genotoxicity with the standard Ames test according to standard protocols. Methods Acute oral toxicity of Py-mulin was determined using Kunming mice. The 28-day repeated dose oral toxicity study in SD rats was performed according to OECD guideline No. 407. The bacterial reverse mutation (Ames test) was carried out using four Salmonella typhimurium (S. typhimurium) strains TA97, TA98, TA100 and TA1535 with and without S9 metabolic activation. Results The LD50 values in acute oral toxicity were 2973 mg/kg (female mice) and 3891 mg/kg (male mice) calculated by the Bliss method. In subacute toxicity study, 50 mg/kg Py-mulin did not induce any abnormality in body weight, food consumption, clinical sign, hematology, clinical chemistry, organ weight, and histopathology in all of the treatment groups. However, high doses of Py-mulin (100 and 300 mg/kg) displayed slightly hepatotoxicity to female rats. Furthermore, Py-mulin did not significantly increase the number of revertant colonies of four standard S. typhimurium strains with the doses of 0.16–1000 μg/plate in the Ames study. Conclusions Based on our findings, our study provides some information for the safety profile of Py-mulin.

Cortisone is a metabolite belonging to the corticosteroid class that is used pharmaceutically directly as a drug or prodrug. In addition to its large consumption, its use is linked to several side effects, so pharmaceutical research aims to develop effective drugs with low or no side effects, alternative compounds to cortisone are part of an active investment in ongoing research on drug discovery. Since biotransformation can be considered a source of new molecules with potential therapeutic use, the present work focuses on a preliminary in vitro study aimed at evaluating the mutagenic, anti-inflammatory, antioxidant and neuroprotective activity of SCA and SCB molecules obtained from the biotransformation of cortisone using Rh. Rhodnii strain DSM 43960. The results obtained are very encouraging due to the safety of biotransformed compounds with reference to genotoxicity checked by Ames test, to the very high antioxidant capacity and to the anti-inflammatory activity. In fact, thecompounds inhibited both the TNFα-stimulated expression and secretion of NFkB target cytokines, and COX activity, and can activate the glucocorticoid receptor. Finally SCA and SCB exhibited neuroprotective properties. [ABSTRACT FROM AUTHOR]

Coumarins and chalcones are compounds widely found in plants or obtained by synthetic methods which possess several biological properties including antioxidant, anti-inflammatory, and antitumor effects. A series of coumarin-chalcone hybrids were synthesized to improve their biological actions and reduce potential adverse effects. Considering the applications of these molecules, a coumarin-chalcone hybrid [7-methoxy-3-(E)-3-(3,4,5-trimethoxyphenyl) acryloyl-2 H-chromen-2-one] (4-MET) was synthesized and the genotoxic, cytotoxic, and protective effects assessed against damage induced by different mutagens. First, in silico tools were used to predict biological activity of 4-MET which indicated a chemopreventive potential. Subsequently, the genotoxic/antigenotoxic activities of 4-MET were determined both in vitro (Ames test) and in vivo (micronucleus (MN) test and comet assay). In addition, molecular docking simulations were performed between 4-MET and glutathione reductase, an important cellular detoxifying enzyme. Our results indicated that 4-MET was not mutagenic in the Ames test; however, when co-treated with sodium azide or 4-nitroquinoline 1-oxide (4-NQO), 4-MET significantly reduced the harmful actions of these mutagens. Except for a cytotoxic effect after 120 hr treatment, 4-MET alone did not produce cytotoxicity or genotoxicity in the MN test and comet assay. Nonetheless, all treatments of 4-MET with cyclophosphamide (CPA) showed a chemoprotective effect against DNA damage induced by CPA. Further, molecular docking analysis indicated a strong interaction between 4-MET and the catalytic site of glutathione reductase. These effects may be related to (1) damage prevention, (2) interaction with detoxifying enzymes, and (3) DNA-repair induction. Therefore, data demonstrated that 4-MET presents a favorable profile to be used in chemopreventive therapies. [ABSTRACT FROM AUTHOR]

Root tubers of Asphodelus bento-rainhae subsp. bento-rainhae (AbR), an endemic species with relevant interest due to conservation concerns, and Asphodelus macrocarpus subsp. macrocarpus (AmR) have been traditionally used for culinary and medicinal purposes, mainly associated with skin infection and inflammation. The present study aims to establish the quality control criteria for the proper characterization of dried root tubers of both species as herbal substances, together with their preclinical safety assessments. Botanical identification using macroscopic and microscopic techniques and phytochemical evaluation/quantification of the main classes of marker secondary metabolites, including phenolic compounds (flavonoid, anthraquinone, condensed and hydrolysable tannin) and terpenoids were performed. Additionally, in vitro genotoxicity/mutagenicity was evaluated by Ames test. Evident morphological differences in the development of tubercles (3.5 × 1 cm in AbR and 8.7 × 1.4 cm in AmR) and microscopicly in the arrangements and characteristics of the vascular cylinder (metaxylem and protoxylems) were found. Anatomical similarities such as multiple-layered epidermis (velamen) and the cortex area with thin-walled idioblasts (134 ± 2.9 µm and 150 ± 27.6 µm) containing raphide crystals (37.2 ± 14.2 µm and 87.7 ± 15.3 µm) were observed between AbR and AmR, respectively. Terpenoids (173.88 ± 29.82 and 180.55 ± 10.57 mg OAE/g dried weight) and condensed tannins (128.64 ± 14.05 and 108.35 ± 20.37 mg CAE/g dried weight) were found to be the main class of marker secondary metabolites of AbR and AmR extracts, respectively. No genotoxicity (up to 5 mg/plate, without metabolic activation) was detected in these medicinal plants' tested extracts. The obtained results will contribute to the knowledge of the value of the Portuguese flora and their future commercial cultivation utilization as raw materials for industrial and pharmaceutical use. [ABSTRACT FROM AUTHOR]