Maternal exercise during pregnancy modulates genotoxicity caused by high fructose consumption in mice offspring.

Pregnancy is a period that is characterized by several metabolic and physiological changes and requires special attention, especially with regard to the relationship between feeding and foetal development. Therefore, the objective of this study was to evaluate whether the practice of voluntary physical exercise (VPE) in combination with chronic consumption of fructose (FRU) from the beginning of life and/or until the gestational period causes genotoxic changes in pregnant females and in their offspring. Seventy Swiss female mice received FRU in the hydration bottle and/or practiced VPE for 8 weeks (prepregnancy/pregnancy). After the lactation period, the offspring groups were separated by sex. It was observed that the consumption of FRU affected the food consumption, serum concentration of FRU, and glycemic profile in the mothers and that the VPE decreases these parameters. In addition, FRU was genotoxic in the mothers' peripheral tissues and VPE had a preventive effect on these parameters. The offspring showed changes in food consumption, serum FRU concentration, and body weight, in addition to an increase in the adiposity index in male offspring in the FRU (FRU) group and a decrease in the FRU + VPE group. FRU leads to hepatic steatosis in the offspring and VPE was able to decrease the area of steatosis. In addition, FRU led to genotoxicity in the offspring and VPE was able to modulate this effect, reducing damages. In conclusion, we observed that all interventions with VPE had nutritional, genetic, and biochemical benefits of the mother and her offspring.

Matrine and Oxymatrine: evaluating the gene mutation potential using in silico tools and the bacterial reverse mutation assay (Ames test).

The quinolizidine alkaloids matrine and its N-oxide oxymatrine occur in plants of the genus Sophora. Recently, matrine was sporadically detected in liquorice products. Morphological similarity of the liquorice plant Glycyrrhiza glabra with Sophora species and resulting confusion during harvesting may explain this contamination, but use of matrine as pesticide has also been reported. The detection of matrine in liquorice products raised concern as some studies suggested a genotoxic activity of matrine and oxymatrine. However, these studies are fraught with uncertainties, putting the reliability and robustness into question. Another issue was that Sophora root extracts were usually tested instead of pure matrine and oxymatrine. The aim of this work was therefore to determine whether matrine and oxymatrine have potential for causing gene mutations. In a first step and to support a weight-of-evidence analysis, in silico predictions were performed to improve the database using expert and statistical systems by VEGA, Leadscope (Instem®), and Nexus (Lhasa Limited). Unfortunately, the confidence levels of the predictions were insufficient to either identify or exclude a mutagenic potential. Thus, in order to obtain reliable results, the bacterial reverse mutation assay (Ames test) was carried out in accordance with OECD Test Guideline 471. The test set included the plate incorporation and the preincubation assay. It was performed with five different bacterial strains in the presence or absence of metabolic activation. Neither matrine nor oxymatrine induced a significant increase in the number of revertants under any of the selected experimental conditions. Overall, it can be concluded that matrine and oxymatrine are unlikely to have a gene mutation potential. Any positive findings with Sophora extracts in the Ames test may be related to other components. Notably, the results also indicated a need to extend the application domain of respective (Q)SAR tools to secondary plant metabolites.

Synthetic auxin herbicide 2,4-D and its influence on a model BY-2 suspension.

2,4-D is a broadly used auxin herbicide. The presence of the 2,4-D synthetic auxin in the medium is imperative for long-term BY-2 tobacco suspension viability. The precise mechanism of this symbiosis of the suspension and the synthetic auxin remains unclear. Our goal was to study the hormonal regulation of the growth of the cell suspension; and to describe the experiments clarifying the interaction between the chosen growth regulators and phytohormones on the cellular level, specifically between the 2,4-D synthetic auxin and the native stress phytohormone - ethylene. This study examined the influence of low 2,4-D concentrations stimulating cell growth in vitro as well as the influence of high herbicide concentrations on the model tobacco BY-2 suspension. The culture took 6 days. Different parameters were evaluated, including the influence of different 2,4-D concentrations on the production of the phytohormone ethylene and its precursor 1-Aminocyclopropane-1-carboxylic acid (ACC) in the tobacco cells. The content of 2,4-D in the cells and the medium was established. The observations of the morphological changes showed that a heavy impregnation of the cell walls taking place depending on the concentration of 2,4-D. A dramatic increase in protective polysaccharides and a remodulation of the cell walls by the formation of a pectin shield in artificial conditions were expected and observed. At the same time, massive production of the stress phytohormone ethylene took place, and, because of that, plant mutagenicity, anomalous tumour-type proliferation growth, and the production of supercells were observed. The hypothesis of the protective shield is discussed.

A path from synthesis to emergency use authorization of molnupiravir as a COVID-19 therapy.

Coronaviruses are a group of enveloped viruses with non-segmented, single-stranded, and positive-sense RNA genomes. It belongs to the 'Coronaviridae family', responsible for various diseases, including the common cold, SARS, and MERS. The COVID-19 pandemic, which began in March 2020, has affected 209 countries, infected over a million people, and claimed over 50,000 lives. Significant efforts have been made by repurposing several approved drugs including antiviral, to combat the COVID-19 pandemic. Molnupiravir is found to be the first orally acting efficacious drug to treat COVID-19 cases. It was approved for medical use in the UK in November 2021 and other countries, including USFDA, which granted approval an emergency use authorization (EUA) for treating adults with mild to moderate COVID-19 patients. Considering the importance of molnupiravir, the present review deals with its various synthetic strategies, pharmacokinetics, bio-efficacy, toxicity, and safety profiles. The comprehensive information along with critical analysis will be very handy for a wide range of audience including medicinal chemists in the arena of antiviral drug discovery especially anti-viral drugs against any variant of COVID-19.

Cytogenotoxicity and inflammatory response in liver of rats exposed to different doses of cannabis nano emulsions.

Cannabis is the most used illicit substance for recreational purposes around the world. However, it has become increasingly common to witness the use of approved cannabis preparations for symptoms management in various diseases. The aim of this study was to investigate the effects of cannabis nano emulsion in the liver of Wistar rats, with different proportions of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). For this, a total of 40 male Wistar rats were distributed into 5 groups, as follows (n = 8 per group): Control: G1, Experimental group (G2): treated with cannabis nano emulsion (THC and CBD) at a dose of 2.5 mg/kg, Experimental group (G3): treated with cannabis nano emulsion (THC and CBD) at a dose of 5 mg/kg, Experimental group (G4): treated with cannabis nano emulsion (CBD) at a dose of 2.5 mg/kg; Experimental group (G5): treated with cannabis nano emulsion (CBD) at a dose of 5 mg/kg. Exposure to the nano emulsion was carried out for 21 days, once a day, orally (gavage). Our results showed that cannabis nano emulsions at higher doses (5 mg/kg), regardless of the composition, induced histopathologic changes in the liver (G3 and G5) in comparison with the control group. In line with that, placental glutathione S-transferase (GST-P) positive foci increased in both G3 and G5 (p < 0.05), as well as the immune expression of Ki-67, vascular endothelial growth factor (VEGF) and p53 (p < 0.05). Also, the nano emulsion intake induced an increase in the number of micronucleated hepatocytes in G5 (p < 0.05) whereas G3 showed an increase in binucleated cells (p < 0.05). As for metanuclear alterations, karyolysis and pyknosis had an increased frequency in G3 (p < 0.05). Taken together, the results show that intake of cannabis nano emulsion may induce degenerative changes and genotoxicity in the liver in higher doses, demonstrating a clear dose-response relationship.

Genotoxic and antiproliferative properties of Endopleura uchi bark aqueous extract.

The bark extract from Endopleura uchi has been widely used in traditional medicine to treat gynecological-related disorders, diabetes, and dyslipidemias albeit without scientific proof. In addition, E. uchi bark extract safety, especially regarding mutagenic activities, is not known. The aim of this study was to determine the chemical composition, antitumor, and toxicological parameters attributed to an E. uchi bark aqueous extract. The phytochemical constitution was assessed by colorimetric and chromatographic analyzes. The antiproliferative effect was determined using sulforhodamine B (SRB) assay using 4 cancer cell lines. Cytotoxic and genotoxic activities were assessed utilizing MTT and comet assays, respectively, while mutagenicity was determined through micronucleus and Salmonella/microsome assays. The chromatographic analysis detected predominantly the presence of gallic acid and isoquercitrin. The antiproliferative effect was more pronounced in human colon adenocarcinoma (HT-29) and human breast cancer (MCF-7) cell lines. In the MTT assay, the extract presented an IC50 = 39.1 µg/ml and exhibited genotoxic (comet assay) and mutagenic (micronucleus test) activities at 20 and 40 µg/ml in mouse fibroblast cell line (L929) and mutagenicity in the TA102 and TA97a strains in the absence of S9 mix. Data demonstrated that E. uchi bark possesses bioactive compounds which exert cytotoxic and genotoxic effects that might be associated with its antitumor potential. Therefore, E. uchi bark aqueous extract consumption needs to be approached with caution in therapeutic applications.

Ninety-day toxicity and genotoxic effects of synthetically derived fully saturated forms of anacardic acid in mice.

Organically synthesized fully saturated form of Anacardic acid (AA) has previously shown to be effective in the treatment of inflammatory autoimmune disease. In this study, organically synthesized fully saturated form of AA was orally administered to male and female Swiss albino mice for 90 consecutive days at doses of 25, 50 and 100 mg/kg BW (n = 20 per sex/group). Administration of AA was well tolerated at all dose levels. The treated animals did not show a dose-response toxicity in their hematology, liver, or metabolic profile. Minimally significant changes in serum biochemistry and hematology parameters were noted, but these were not considered to be of biological or toxicological importance and were not outside the known accepted ranges. Sporadic differences in organ weights were observed between groups, but all were minimal (<10%) and unlikely to indicate toxicity. The incidence of histopathological lesions was comparable between treated and control groups across all tested organs. Based upon these findings, the no-observed-adverse-effect level was determined to be ≥ 100 mg/kg BW, which was the highest dose tested. There were no genotoxic (mutagenic and clastogenic) effects seen in In-vivo micronucleus test, In-vitro chromosomal aberration test and Bacterial reverse mutation test. These results support, no genotoxicity and no toxicity associated with oral consumption of AA in mice as a dietary supplement for beverages and food.

Estimation of Acceptable Daily Intake Values based on Modeling and In Vivo Mutagenicity of NDSRIs of Fluoxetine, Duloxetine and Atomoxetine.

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 M7R2-designated Cohort of Concern.

Retrospective application of ICH M7 to anti-hypertensive drugs in Brazil: Risk assessment of potentially mutagenic impurities.

Potentially mutagenic impurities are likely to be formed in any drug substance, since their synthesis requires reactive intermediates which may also react with DNA. The ICH M7 guideline, which defines how to risk assess and control mutagenic impurities, was first published in 2014 and is not to be applied retrospectively; however, some impurities have been found above the permitted limits in drug products which were already on the market. This study assessed the implications of applying ICH M7 retrospectively to anti-hypertensive drugs marketed in Brazil by performing a risk assessment and establishing control strategies. The manufacturing processes of 15 drug substances were evaluated and 262 impurities were identified, from which 21% were classified as potentially mutagenic. Most of the impurities were identified below ICH M7 acceptable limits, except for impurities described in a pharmacopoeial monograph. Compendial specifications are defined based on scientific evidence and play an important role in setting quality and safety standards for pharmaceuticals, however there are opportunities for further alignment with ICH guidelines, aiming for a holistic assessment of the impurities profile to ensure the safety of medicines.

Determining recommended acceptable intake limits for N-nitrosamine impurities in pharmaceuticals: Development and application of the Carcinogenic Potency Categorization Approach (CPCA).

N-Nitrosamine impurities, including nitrosamine drug substance-related impurities (NDSRIs), have challenged pharmaceutical industry and regulators alike and affected the global drug supply over the past 5 years. Nitrosamines are a class of known carcinogens, but NDSRIs have posed additional challenges as many lack empirical data to establish acceptable intake (AI) limits. Read-across analysis from surrogates has been used to identify AI limits in some cases; however, this approach is limited by the availability of robustly-tested surrogates matching the structural features of NDSRIs, which usually contain a diverse array of functional groups. Furthermore, the absence of a surrogate has resulted in conservative AI limits in some cases, posing practical challenges for impurity control. Therefore, a new framework for determining recommended AI limits was urgently needed. Here, the Carcinogenic Potency Categorization Approach (CPCA) and its supporting scientific rationale are presented. The CPCA is a rapidly-applied structure-activity relationship-based method that assigns a nitrosamine to 1 of 5 categories, each with a corresponding AI limit, reflecting predicted carcinogenic potency. The CPCA considers the number and distribution of α-hydrogens at the N-nitroso center and other activating and deactivating structural features of a nitrosamine that affect the α-hydroxylation metabolic activation pathway of carcinogenesis. The CPCA has been adopted internationally by several drug regulatory authorities as a simplified approach and a starting point to determine recommended AI limits for nitrosamines without the need for compound-specific empirical data.

Multigenerational effects and mutagenicity of three flame retardants on germ cells in Caenorhabditis elegans.

Flame retardants (FRs) have raised public concerns because of their environmental persistence and negative impacts on human health. Recent evidence has revealed that many FRs exhibit reproductive toxicities and transgenerational impacts, whereas the toxic effects of FRs on germ cells remain barely explored. Here we investigated the multigenerational effects of three flame retardants (TBBPA, TCEP and TCPP) on germ cell development in Caenorhabditis elegans, and examined the germ cell mutagenicity of these FRs by using whole genome sequencing. Parental exposure to three FRs markedly increased germ cell apoptosis, and impeded oogenesis in F1-F6 offspring. In addition, the double-increased mutation frequencies observed in progeny genomes uncover the mutagenic actions of FRs on germ cells. Analysis of mutation spectra revealed that these FRs predominantly induced point mutations at A:T base pairs, whereas both small and large indels were almost unaffected. These results revealed the long-term effects of FRs on development and genomic stability of germ cells, which may pose risks to environmental organisms and human reproductive health. Taken together, our findings suggest that germ cell mutagenicity should be carefully examined for the environmental risk assessment of FRs and other emerging pollutants.

Mancozeb induces cytogenotoxicity in meristematic cells of Allium cepa L.

Mancozeb is a fungicide of the dithiocarbamate functional group, and it is widely used in agriculture to control various fungal diseases. Thus, studies detailing its toxicological characteristics are necessary, as the population may be exposed through the consumption of food or water contaminated with mancozeb. The aim of this study was to evaluate the cytotoxic, genotoxic, and mutagenic potentials of this dithiocarbamate using the Allium cepa L. test system as well as its cytotoxicity in erythrocytes of female rats (Rattus norvegicus). The meristematic roots of A. cepa bulbs were exposed to various concentrations of mancozeb (62.5, 125, 250, and 500 mg/L) for 24, 48, and 72 h to determine cytotoxicity by evaluating the mitotic index (MI), chromosomal aberrations (CA), and nuclear anomalies (NA) for genotoxicity analysis and micronuclei (MN) for mutagenicity analysis. Distilled water and copper sulfate (0.0006 mg/L) were used as the negative control (NC) and positive control (PC), respectively. The MI and the sum of CA and NA of all the mancozeb concentrations showed a significant difference (p ≤ 0.05) in relation to the NC, indicating possible cytotoxicity and genotoxicity induced by mancozeb. Additionally, MN significantly increased with mancozeb concentration from 250 mg/L to 500 mg/L in 24 h when compared to NC. In another study model, mancozeb showed to be cytolytic at concentrations starting from 125 mg/L. Therefore, these results indicate that mancozeb causes cytogenetic alterations and mutagenicity at lower concentrations than those used in agriculture, which emphasizes the need for more care when managing this fungicide.

In vitro Genotoxicity and In silico Docking Analyses of the Essential Oils of Thuja orientalis.

Two main objectives were pursued to assess the reliability of Thuja orientalis essential oils (TOEO). The first objective was to extract TOEO, analyze them by GC-MS, and determine their in vitro genotoxicity against selected plants using the RAPD-PCR method. The second objective was to evaluate the in-silico toxicity of TOEO. The binding sites and energies of each content was calculated against B-DNA. In-silico analyses were performed using a simulation program, AutoDock Vina, and Toxicity Estimation Software Tools. 3-carene, cedrol, and 2-pinene were identified as the predominant components. In vitro studies showed that the TOEO had a more significant impact on reducing genomic stability in wheat compared to the amaranth. The lowest stability was determined as 39.78 % in wheat and 53.58 % in amaranth. Cedrol (-5,7 kcal/mol) and selinene (-5,6 kcal/mol) exhibited the highest binding affinity. The toxicity test indicated that components other than cyclohexene may have toxic effects, none of them were predicted to be mutagenic, and LD50 (mol/kg) values could vary between 1.33 and 1.55.

Mutagenicity Assessment of Homologous Series of Methyl Ester Sulphonates (MES) Using the Bacterial Reverse Mutation (Ames) Test.

Methyl ester sulphonate (MES) is an anionic surfactant that is suitable to be used as an active ingredient in household products. Four palm-based MES compounds with various carbon chains, namely C12, C14, C16 and C16/18 MES, were assayed by the in vitro bacterial reverse mutation (Ames) test in the Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 and the Escherichia coli strain WP2 uvrA, with the aim of establishing the safety data of the compounds, specifically their mutagenicity. The test was also carried out on linear alkylbenzene sulphonate (LAS) for comparison. The plate incorporation method was conducted according to the Organization for Economic Cooperation and Development (OECD) Test Guideline 471. All compounds were tested at five analysable non-cytotoxic concentrations, varying from .001 mg/plate to 5 mg/plate, with and without S-9 metabolic activation. All tested concentrations showed no significant increase in the number of revertant colonies compared to revertant colonies of the negative control. The Ames test indicated that each concentration of C12, C14, C16, C16/18 MES, and LAS used in this study induced neither base-pair substitutions nor frame-shift mutations in the S. typhimurium strains TA98, TA100, TA1535, and TA1537 and the E. coli strain WP2 uvrA. The results showed that C12, C14, C16 and C16/18 MES have no potential mutagenic properties in the presence and absence of S-9 metabolic activation, similarly to LAS. Therefore, the MES is safe to be used as an alternative to petroleum-based surfactants for household cleaning products.

Anticancer Potential and Safety Profile of ß-Lapachone In Vitro.

Ipê is a plant of the Bignoniaceae family. Among the compounds extracted from this tree, lapachol is notable because its structural modification allows the production of ß-lapachone, which has anticancer properties. The objective of this work was to test this hypothesis at a cellular level in vitro and assess its potential safety for use. The following tests were performed: MTT cell viability assay, apoptotic index determination, comet assay, and micronucleus test. The results showed that ß-lapachone had a high cytotoxic capacity for all cell lines tested: ACP02 (gastric adenocarcinoma cells), MCF7 (breast carcinoma cells), HCT116 (colon cancer cells) and HEPG2 (hepatocellular carcinoma cells). Regarding genotoxicity, the exposure of cells to sublethal doses of ß-lapachone induced DNA damage (assessed by the comet assay) and nuclear abnormalities, such as nucleoplasmic bridges and nuclear buds (assessed by the micronucleus test). All tested cell lines responded similarly to ß-lapachone, except for ACP02 cells, which were relatively resistant to the cytotoxic effects of the compound in the MTT test. Our results collectively indicate that although ß-lapachone showed antiproliferative activity against cancer cell lines, it also caused harmful effects in these cells, suggesting that the use of ß-lapachone in treating cancer should be carried out with caution.

Moderate India Pale Ale beer consumption promotes antigenotoxic and non-mutagenic effects in ex vivo and in vivo mice models.

BACKGROUND: Discussion of the benefits of moderate alcohol consumption is ongoing. Broadly, research focusing on ethanol consumption tends to report no benefits. However, studies that distinguish between different types of alcoholic beverages, particularly beers, often reveal positive effects. The present study evaluated the genotoxic and mutagenic effects of moderate chronic consumption of India Pale Ale (IPA) craft beer. Sixty-four adult male Swiss mice were used and divided into control and treatment groups receiving water, IPA beer with 55.23 g of ethanol per liter of beer, aqueous solution with 55.23 g of ethanol per liter, and hop infusion ad libitum for 30 days. After this period, the animals were genetically evaluated with a comet assay. For the ex vivo comet assay, blood was collected and exposed to hydrogen peroxide (H2O2). For the in vivo assay, the alkylating agent cyclophosphamide (CP) was administered to the groups after blood collection and sacrificed after 24 h. Brain, liver, and heart tissues were analyzed. Bone marrow was collected and submitted to the micronucleus test. RESULTS: The groups treated with IPA beer, ethanol, and hops did not show genotoxic and mutagenic action in the blood, brain, heart, or liver. The antigenotoxic action of IPA beer and hops was observed in both in vivo and ex vivo models, showing a similar reduction in DNA damage caused by CP. There was no significant difference between the groups with regard to the formation of micronuclei by CP. CONCLUSION: Moderate chronic consumption of IPA beer and hops infusion showed antigenotoxic effects in mice but no antimutagenic action. © 2024 Society of Chemical Industry.

Preliminary study on the enhanced bioremediation of PAH-contaminated soil in Beijing and assessment of remediation effects based on toxicity tests.

In this study, we focused on soil contaminated by polycyclic aromatic hydrocarbons (PAHs) at typical coking-polluted sites in Beijing, conducted research on enhanced PAH bioremediation and methods to evaluate remediation effects based on toxicity testing, and examined changes in pollutant concentrations during ozone preoxidation coupled with biodegradation in test soil samples. The toxicity of mixed PAHs in soil was directly evaluated using the Ames test, and the correlation between mixed PAH mutagenicity and benzo(a)pyrene (BaP) toxicity was investigated in an effort to establish a carcinogenic risk assessment model based on biological toxicity tests to evaluate remediation effects on PAH-contaminated soil. This study provides a theoretical and methodological foundation for evaluating the effect of bioremediation on PAH-contaminated soil at industrially contaminated sites. The results revealed that the removal rate of PAHs after 5 min of O3 preoxidation and 4 weeks of soil reaction with saponin surfactants and medium was 83.22%. The soil PAH extract obtained after remediation had a positive effect on the TA98 strain at a dose of 2000 µg·dish-1, and the carcinogenic risk based on the Ames toxicity test was 8.98 times greater than that calculated by conventional carcinogenic PAH toxicity parameters. The total carcinogenic risk of the remediated soil samples was approximately one order of magnitude less than that of the original soil samples.

Ecotoxicological evaluation of surface waters in Northern Namibia.

The increasing pressure on freshwater systems due to intensive anthropogenic use is a big challenge in central-northern Namibia and its catchment areas, the Kunene and the Kavango Rivers, and the Cuvelai-Etosha Basin, that provide water for more than 1 million people. So far, there is no comprehensive knowledge about the ecological status and only few knowledge about the water quality. Therefore, it is crucial to learn about the state of the ecosystem and the ecological effects of pollutants to ensure the safe use of these resources. The surface waters of the three systems were sampled, and three bioassays were applied on three trophic levels: algae, daphnia, and zebrafish embryos. Additionally, in vitro assays were performed to analyze mutagenicity (Ames fluctuation), dioxin-like potential (micro-EROD), and estrogenicity (YES) by mechanism-specific effects. The results show that acute toxicity to fish embryos and daphnia has mainly been detected at all sites in the three catchment areas. The systems differ significantly from each other, with the sites in the Iishana system showing the highest acute toxicity. At the cellular level, only weak effects were identified, although these were stronger in the Iishana system than in the two perennial systems. Algae growth was not inhibited, and no cytotoxic effects could be detected in any of the samples. Mutagenic effects and an estrogenic potential were detected at three sites in the Iishana system. These findings are critical in water resource management as the effects can adversely impact the health of aquatic ecosystems and the organisms within them.

In vitro genotoxicity assessment of French fries from mass catering companies: a preliminary study.

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.

From cultivation to cancer: formation of N-nitrosamines and other carcinogens in smokeless tobacco and their mutagenic implications.

Tobacco use is a major cause of preventable morbidity and mortality globally. Tobacco products, including smokeless tobacco (ST), generally contain tobacco-specific N-nitrosamines (TSNAs), such as N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK), which are potent carcinogens that cause mutations in critical genes in human DNA. This review covers the series of biochemical and chemical transformations, related to TSNAs, leading from tobacco cultivation to cancer initiation. A key aim of this review is to provide a greater understanding of TSNAs: their precursors, the microbial and chemical mechanisms that contribute to their formation in ST, their mutagenicity leading to cancer due to ST use, and potential means of lowering TSNA levels in tobacco products. TSNAs are not present in harvested tobacco but can form due to nitrosating agents reacting with tobacco alkaloids present in tobacco during certain types of curing. TSNAs can also form during or following ST production when certain microorganisms perform nitrate metabolism, with dissimilatory nitrate reductases converting nitrate to nitrite that is then released into tobacco and reacts chemically with tobacco alkaloids. When ST usage occurs, TSNAs are absorbed and metabolized to reactive compounds that form DNA adducts leading to mutations in critical target genes, including the RAS oncogenes and the p53 tumor suppressor gene. DNA repair mechanisms remove most adducts induced by carcinogens, thus preventing many but not all mutations. Lastly, because TSNAs and other agents cause cancer, previously documented strategies for lowering their levels in ST products are discussed, including using tobacco with lower nornicotine levels, pasteurization and other means of eliminating microorganisms, omitting fermentation and fire-curing, refrigerating ST products, and including nitrite scavenging chemicals as ST ingredients.