The in vitro micronucleus technique

Genotoxicity of putrescine and its effects on gene expression in HepG2 cell line

Decomposing bodies release necro-leachate, a toxic fluid containing harmful compounds such as biogenic amines. This study investigated the genotoxic effects of the different concentrations (0.5, 1.4, 2.3, 3.2 mM) of bioamine putrescine on HepG2 cells using the comet assay, the micronucleus test, and gene expression analysis. The results were compared to negative control and indicated significant DNA damage in the comet assay highlighting tail DNA intensity that exhibited significant differences across all tested concentrations (0.5 = 192 %, 1.4 = 189 %, 2.3 = 208 %, 3.2 = 132 %). The micronucleus test revealed a significant increase in micronuclei for concentrations 0.5 (193 %), 1.4 (229 %), 2.3 (206 %); nuclear buds 3.2 (173 %); chromosomal bridges 3.2 (735 %). Furthermore, genes linked to oxidative stress and DNA damage exhibited statistically significant expression alterations. These findings suggest that putrescine has genotoxic potential in human-derived HepG2 cells, raising concerns about cemetery contaminants' occupational and environmental risks. This study is the first to assess putrescine's toxicity as an environmental pollutant, as previous research has mainly focused on its role in the food sector. These insights highlight the potential threats necro-leachate poses to environmental health, emphasizing the need for further research on cemetery pollution.

Genotoxicity assessment of food-grade titanium dioxide

Food-grade titanium dioxide (E171 in Europe), which contains nanoscale particles (NPs), has been approved and used as a white pigment in various common foods. Concerns are growing over the use of E171 as a safe food additive. The purpose of the present research is to evaluate the genotoxicity of E171 using in vivo and in vitro testing systems. In vitro studies, Chinese hamster lung (V79) fibroblast cells were exposed to E171 at doses of 25, 50, 100, and 200 μg/mL. No gene mutations were observed after 24 hours of treatment at any concentration using the hypoxanthine guanine phosphoribosyltransferase (Hprt) gene mutation assay. In vivo study, the healthy Kunming mice and SD rats were exposed to E171 through intragastric administration at doses of 250, 500 and 1000 mg/kg body weight every day for 15 days. Genotoxic potential of E171 was evaluated by micronucleus (MN) and comet assays in accordance with the OECD guideline. However, the results showed that E171 did not increase the frequency of bone marrow micronuclei or induce DNA strand breaks in rat liver cells at the doses used in this experiments. Under the conditions described in this report, E171 was concluded to be negative in these in vivo and in vitro genotoxicity tests. These findings suggest that E171 is not genotoxic, offering valuable data for risk assessment.

Maternal Thrombophilia Disrupts Fetal Redox Homeostasis

Considering that the fetal redox homeostasis is a key factor for normal prenatal development, this study researched the effects of maternal thrombophilia on fetal redox homeostasis by assessing the redox profile of amniotic fluid cells and amniotic fluid during the second trimester of pregnancy. Concentration of redox biomarkers (superoxide anion, O2.-; hydrogen peroxide, H2O2; nitric oxide, NO; peroxynitrite, ONOO-; lipid peroxides, LPO, micronuclei, reduced glutathione, GSH; oxidized glutathione, GSSG) were assayed in the amniotic fluid cells and amniotic fluid of healthy pregnant women and pregnant women with thrombophilia gestational age from 16 to 18 weeks. Results of this study indicate that pregnant women with thrombophilia have significantly higher concentrations of O2.-, NO, ONOO-, and LPO but lower concentrations of H2O2, GSH, and GSSG in the amniotic fluid cells, as well as a higher concentration of GSSG in the amniotic fluid. No difference is shown in concentration of O2.-, H2O2, NO, ONOO-, LPO, and GSH in the amniotic fluid, as well as in frequency of micronuclei in the amniotic fluid cells among investigated groups of pregnant women. The present study provides the first evidence that babies born to mothers with thrombophilia in the second trimester of intrauterine life experience intense oxidative stress characterized by overproduction of O2.-, NO, ONOO-, and LPO, as well as GSH depletion.

Toxicological assessment of niga-ichigoside F1 and 2β,3β-19α-trihydroxyursolic acid derived from Rubus imperialis (Rosaceae): determining the safety using human peripheral blood mononuclear cells (PBMC)

Rubus imperialis Chum. Schl. (Rosaceae) is used in traditional medicine as a remedy to treat diabetes and other diseases. However, there are reports that the extract of this plant and others of the Rubus genus may produce cellular and/or genetic toxicity. Niga-ichigoside F1 (NIF1) and 2β,3β-19α-trihydroxyursolic acid (2B) are major compounds found in R. imperialis extract known to exert pharmacological effects which may be responsible for the observed toxicity. Thus, this study was aimed to examine the cytogenotoxic potential of NIF1 and 2B in human peripheral blood mononuclear cells (PBMC) following acute exposure. Cytotoxicity was determined by trypan blue staining and genotoxicity by micronucleus and comet assays. Data obtained showed that both compounds, at concentrations ranging from 0.1 and 20 µg/ml, did not markedly affect cell viability. In addition, genetic toxicity testing (comet assay) detected no evidence of DNA damage or chromosomal mutations by the micronucleus test. Under these experimental conditions and considering that both compounds exhibit biological effects at low concentrations, it may be concluded that NIF1 and 2B did not induce cytogenotoxic effects in primary human PBMC.

Relative biological effectiveness of 31 meV thermal neutrons in peripheral blood lymphocytes

The reported relative biological effectiveness (RBE) for thermal neutrons has a large range (5-51, for cytogenetic endpoints), which can confound radiation protection decision-making. To determine whether thermal neutron spectra can influence RBE, the RBE of reactor-derived thermal neutrons of average energy 31 meV was evaluated in human peripheral blood lymphocytes using two classical DNA double-strand break endpoints: the dicentric chromosome assay (DCA) and the cytokinesis-block micronucleus assay. Dose-response curves for 41 to 408 mGy revealed a preference for linear regression. Maximum RBE (RBEM) values of 6.7 ± 0.9 and 4.4 ± 0.7 were calculated for the DCA and the micronucleus assay, respectively. These 31 meV RBEM values were significantly lower than our prior results for 64 meV thermal neutrons, which yielded a DCA RBEM of 11.3 ± 1.6 and a micronucleus RBEM of 9.0 ± 1.1. Dose-specific RBE values decreased with increasing dose for both assays. Microdosimetry simulations demonstrated similar quality factor values for both thermal neutron spectra. Dose deposition differences on the cellular scale, the difference in dose rate between irradiation configurations, or a not-yet understood phenomenon may be responsible for the RBE difference between the 31 and 64 meV thermal spectra. These findings indicate that the currently accepted radiation weighting factor wR value of 2.5 for thermal neutrons may underestimate the radiation detriment to small or shallow tissue targets including the lens of the eye.

Linear energy transfer optimized proton therapy for rectal cancer

PURPOSE

To evaluate the feasibility and utility of an LET-optimized proton treatment planning algorithm in locally advanced rectal cancer and to assess whether the degree of LET-optimization achieved in clinical plans improves efficacy and toxicity in preclinical models.

MATERIALS AND METHODS

A series of five rectal cancer patients treated with standard 25 fraction clinical proton plans were re-planned using an LET-optimization treatment planning algorithm and evaluated for dosimetric endpoints. LET-optimized plans were generated using an algorithm which iteratively increases the weights of higher LET spots in GTV and lower LET in OARs. Murine and in vitro preclinical models of tumor efficacy and normal tissue toxicity were evaluated using comparable LETd range to that achieved in clinical LET-optimized plans.

RESULTS

LET-optimized proton plans increased dose-averaged LET (LETd) in the GTV and LET-weighted dose in the GTV, and CTV5625cGy V100% coverage. At the same time, LET-optimization also decreased mean LET-weighted dose to bladder and small bowel, as well as small bowel V30Gy(cc) compared to standard proton plans. Optimizing the LETd to a volume of GTV-3 mm further increased LETd compared to total GTV. LET-optimization in preclinical models increased tumor efficacy in colorectal cancer cell lines in vitro and decreased small bowel radiation enteropathy in murine models of normal tissue toxicity.

CONCLUSIONS

LET-optimized proton plans increased LETd in gross tumor while maintaining or improving target coverage and OAR sparing, with acceptable plan robustness. Preclinical models demonstrated that comparable LET-optimization may increase tumor efficacy and decrease normal tissue toxicity in rectal cancer.

Cigarette Smoke and Decreased DNA Repair by Xeroderma Pigmentosum Group C Use a Double Hit Mechanism for Epithelial Cell Lung Carcinogenesis

Emerging evidence suggests a complex interplay of environmental and genetic factors in non-small cell lung cancer (NSCLC) development. Among these factors, compromised DNA repair plays a critical but incompletely understood role in lung tumorigenesis and concurrent lung diseases, such as chronic obstructive lung disease (COPD). In this study, we investigated the interplay between cigarette smoke, DNA damage and repair, focusing on the Nucleotide Excision Repair (NER) protein Xeroderma Pigmentosum Group C (XPC). We found decreased XPC mRNA expression in most NSCLCs compared to subject-matched, non-cancerous lung. In non-cancerous bronchial epithelial cells, cigarette smoke decreased NER, increased total DNA damage and resultant apoptosis, each exacerbated by XPC deficiency. In contrast, lung cancer cells exhibit greater resilience to cigarette smoke, requiring higher doses to induce comparable DNA damage and apoptosis, and are less reliant on XPC expression for survival. Importantly, XPC protects against chromosomal instability in benign bronchial epithelial cells, but not in lung cancer cells. Our findings support a "double hit" mechanism wherein early decreased XPC expression and resultant aberrant DNA repair, when combined with cigarette smoke exposure, may lead to loss of non-malignant epithelial cells (as observed in COPD), and contributes to early NSCLC transition through altered DNA damage response.

Analysis of genotoxic effects of food preservatives sodium acetate (E262) and sodium sulfite (E221) in human lymphocytes

Food preservatives are a large class of food additives that generally prevent microbiological spoilage. Sodium acetate (SA) and sodium sulfite (SS) are food preservatives, and the aim of this study was to investigate their genotoxic and cytotoxic effects. The genotoxic effects of SA and SS were examined by chromosomal aberrations (CA) and micronucleus (MN) assays in human lymphocytes in vitro. In addition, the effects of these two preservative additives on mitotic index (MI) and nuclear division index (NDI) were also investigated. SA and SS significantly induced CAs and MN frequencies and caused a decrease in MI especially at higher concentrations. Neither food preservative caused any change in the NDI. In the light of the data obtained, it was concluded that SA and SS may have cytotoxic and genotoxic effects on human lymphocytes, especially at high concentrations. Therefore, their use at lower concentrations, which may be safer, should be encouraged.

Application of the Buccal Micronucleus Cytome Assay for Genotoxicity Detection in Dogs

In Europe, there is a growing concern for animal welfare, encompassing both their rights and health. Consequently, identifying biomarkers that predict serious pathological conditions has become crucial in veterinary medicine. The Buccal Micronucleus Cytome (BMCyt) assay is a minimally invasive method that uses biomarkers to evaluate DNA damage and chromosomal instability, using exfoliated buccal cells. A rising frequency of anomalies, such as micronuclei formation, strongly indicates an elevated risk of cancer, neurodegenerative diseases, or accelerated aging, potentially originating from exposure to genotoxins and cytotoxins. This method has been validated in humans, but very little research has been conducted on animals. This work aims to provide a detailed description of an optimized method for collecting buccal exfoliated cells in dogs and to characterize a biomarker related to genomic damage using optical and fluorescent microscopy. Samples from dogs in breeding kennels, including pregnant animals, were tested for chromosomal instability. By following procedures similar to those used in humans, we were able to detect and count major nuclear abnormalities. The percentage of micronuclei was higher compared to other studies. Technical aspects, such as avoiding artifacts and ensuring prior training of the operator, must be taken into account. This work validated the BMCyt method for collecting and processing samples in dogs, potentially enhancing the understanding of micronuclei as biomarkers for pre-pathological states in canines.

In silico and in vitro evaluation of the potential genotoxic impurities of vildagliptin

Establishing the safety of impurities in drug substances or products is crucial. The assessment of genotoxicity for these impurities and determining the acceptable limits pose considerable challenges, as recognized in recent guidelines. While the genotoxicity profile of vildagliptin-an oral hypoglycemic drug-is well established, there is limited knowledge about the genotoxic potential of its impurities. In this study, vildagliptin cyclic amidine, vildagliptin diketopiperazine, and vildagliptin amide were assessed in silico and in vitro for mutagenic and clastogenic/aneugenic potential using Ames and micronucleus tests. None of the investigated impurities showed mutagenic or clastogenic potential, thus, are considered non-mutagenic and non-clastogenic/aneugenic in vitro. These findings are consistent with negative in silico predictions for mutagenicity and clastogenicity/aneugenicity in vitro, indicating a good correlation between in silico and in vitro data. In conclusion, this study provides valuable information for the safety assessment of vildagliptin, confirming that its impurities are neither clastogenic/aneugenic nor mutagenic.

Cytotoxicity and genotoxicity of zinc oxide nanoparticles in human peripheral blood mononuclear cells

Zinc oxide nanoparticles (ZnO-NPs) are of interest in biomedical applications, environmental remediation, and agriculture. ZnO-NPs inhibit the growth of phytopathogenic fungi and bacteria. We have evaluated their effects on mitochondrial function and the induction of membrane damage, apoptosis, and DNA damage in human peripheral blood mononuclear cells (PBMC) in vitro. ZnO-NPs caused significant reduction in cell viability and LDH release, indicating damage to cell membranes. Late apoptosis was significant and necrosis was significant at higher concentrations tested. ZnO-NPs did not induce micronucleus formation.

Enhanced antibacterial and genoprotective properties of nanoliposomal Satureja hortensis L. essential oil

Nanoliposomes are drug delivery systems that improve bioavailability by encapsulating therapeutic agents. The main objective of this study was to investigate the effects of nanoliposomal (NL) formulation on enhancing the bioavailability of essential oil. The essential oil of Satureja hortensis (SHO) was encapsulated in nanoliposomes (SHNLs). Physicochemical characterizations of NL formulations (size, charge, polydispersity index [PDI]) were evaluated by dynamic light scattering technique. The nanoliposome encapsulation efficiency (EE) was calculated as 89.90%. The prepared bionanosystems demonstrated significant antibacterial activities against Escherichia coli ATCC 10536, Pseudomonas aeruginosa ATCC 15442, and Staphylococcus aureus ATCC as determined by the agar diffusion method and microdilution tests. Minimum inhibitory concentration (MIC) values for SHNLs were found to be 5.187 µg/µL for E. coli and 2.59 µg/µL for both P. aeruginosa and S. aureus. Importantly, despite the lower substance content, both SHNLs and SHO exhibited comparable antibacterial activity against all tested strains. Furthermore, in order to determine the toxicity profile and possible effects on DNA damage or repair both the genotoxic and antigenotoxic effects of SHNLs were assessed using the cytokinesis-blocked micronucleus (CBMN) method in human lymphocyte cultures. The experimental data collectively indicate that the NL formulation of the S. hortensis essential oil enhances antibacterial activities and provides genoprotective effects against DNA damage. This highlights the significance of liposomal formulations of antioxidants in augmenting their biological activity. The results indicate that SHNLs can be a safe antibacterial agent for the pharmaceutical industry.

Morphological and cellular effects in Boana faber tadpoles (Anura: Hylidae) exposed to atrazine-based herbicide and glyphosate-based herbicide and their mixtures

Atrazine and glyphosate are considered some of the main pollutants for aquatic ecosystems, directly and indirectly affecting non-target organisms, such as amphibians. This study aimed to evaluate the sublethal effects of different concentrations of atrazine-based herbicide (ABH) and glyphosate-based herbicide (GBH) commercial formulations, both individually and in a mixture, through toxicity tests on the larval stage of Boana faber. Tadpoles were exposed to concentrations of ABH (2, 9.33, 10.40, 47.21, and 240 μg L-1) and GBH (65, 144, 280, 500, and 1000 μg L-1), as well as a mixture ABH + GBH, for 7 days. Although survival and swimming activity were not significantly affected by herbicide exposure, tadpoles in all treatments showed damage to the mouth and intestine, changes in size and mass, and an increase in the frequency of micronuclei and other nuclear abnormalities. Despite differences in some variables analyzed, it is not possible to definitively state that there is a difference in the toxicity of these two herbicides, as both caused morphological damage and were cyto-genotoxic. Our findings suggest that exposure to commercial formulations of these herbicides, whether alone or in mixture, can directly impact the quality of life of B. faber tadpoles.

Brasiliensic acid: in vitro cytotoxic and genotoxic, in vivo acute toxicity and in silico pharmacological prediction of a new promising molecule

Brasiliensic acid (Bras) is a chromanone isolated from Calophyllum brasiliense Cambèss. bark extracts with confirmed potential activity on gastric ulcer and Helicobacter pylori infection. This study aimed to investigate the in vitro and in vivo toxicity of Bras and molecular docking studies on its interactions with the H. pylori virulence factors and selected gastric cancer-related proteins. Cytotoxicity was evaluated by alamarBlue© assay, genotoxicity by micronucleus and comet assays, and on cell cycle by flow cytometry, using Chinese hamster epithelial ovary cells. Bras was not cytotoxic to CHO-K1 cells, and caused no chromosomal aberrations, nor altered DNA integrity. Furthermore, Bras inhibited damages to DNA by H2O2 at 1.16 µM. No cell cycle arrest was observed, but apoptosis accounted for 31.2% of the cell death observed in the CHO-K1 at 24 h incubation of the IC50. Oral acute toxicity by Hippocratic screening test in mice showed no relevant behavioral change/mortality seen up to 1,000 mg/kg. The molecular docking approach indicated potential interactions between Bras and the various targets for peptic ulcer and gastric cancer, notably CagA virulence factor of H. pylori and VEGFR-2. In conclusion, Bras is apparently safe and an optimization for Bras can be considered for gastric ulcer and cancer.Communicated by Ramaswamy H. Sarma.

Non-invasive biomarkers for investigating urban metal exposure in neotropical bats

In urban centers, sewage treatment plants (STPs) serve as foraging and shelter areas for bats; however, they are sources of persistent pollutants that affect the health of these animals. This study aimed to investigate the impact of pollutants from an STP on the health of different species of neotropical bats from different guilds using non-invasive biomarkers. A conservation unit, the Silvania National Forest (SNF), was used as a reference area for comparison purposes. Blood, buccal mucosa, and fur samples were obtained for comet assay, micronucleus test, leukocyte profile, and metal concentration analysis in fur. Our results demonstrated that bats collected at the STP show a higher frequency of genotoxic damage, nuclear abnormalities, and an inflammatory response linked to infection than bats from the SNF. Regarding guilds, frugivores and nectarivores showed more pronounced responses to damage, but insectivores bats also showed relevant responses. While STPs are considered a source of pollutants, other urban sources of contamination likely contributed to these results. Still we encourage further studies using other non-invasive biomarkers, detection analysis of different pollutants in biological matrices, and the use of other wildlife species inserted in urban centers.

Potential protection by vitamin D against DNA fragmentation and bone marrow cytotoxicity induced by chloramphenicol

Vitamin D (Vit D) has gained significant attention in health research recently as a result of its potential protective effects against various cellular damages. This study aimed to investigate the ability of vitamin D to mitigate deoxyribonucleic acid (DNA) fragmentation in liver cells and bone marrow cytotoxicity induced by chloramphenicol (CAP). Sixty male albino mice were divided into six groups: control, chloramphenicol-treated (250 and 500 mg/kg body weight, 5 days per week for 4 weeks), vitamin D-treated (800 IU/kg body weight, 5 days per week for 4 weeks) and vitamin D plus chloramphenicol-treated groups. Results of DNA fragmentation test revealed that oral treatment with low and high doses of CAP significantly increased the frequency of DNA fragmentation in liver cells in comparison with the control, whereas oral treatment with vitamin D alone or plus low and high doses of chloramphenicol significantly reduced the genotoxicity in liver cells in comparison with the control group. Micronucleus analysis showed that CAP treatment at low and high doses significantly increased micronuclei formation and cytotoxicity in bone marrow cells. However, vitamin D significantly reduced the micronuclei formation in bone marrow cells of mice treated with chloramphenicol. Vitamin D alone showed no significant difference in the frequency of micronuclei and bone marrow cytotoxicity compared to the control group. Accordingly, further research exploring the mechanisms underlying the protective effects of vitamin D and investigating optimal dosing regimens is warranted. Also, clinical studies evaluating the efficacy of vitamin D supplementation to mitigate the adverse effects of chloramphenicol in human patients are recommended.

Risk assessment of 2β,3β-19α-trihydroxyursolic acid from Rubus imperialis (Rosaceae) in HepG2/C3A cells via genotoxicity, metabolism, and cell growth

Rubus imperialis (Rosaceae) is a Brazilian medicinal plant that already exhibited therapeutical perspectives. However, previous studies revealed cellular and/or genetic toxicity of extracts from aerial parts of this plant, as well as other species of the Rubus genus. Being 2β,3β-19α-trihydroxyursolic acid (2B) one of the major compounds of this plant, with proven pharmacological effect, it is important to investigate the biosafety of this isolated compound. Therefore, in the present study, (2B) was tested by several cytogenotoxic endpoints up to 20 μg/ml in human hepatoma HepG2/C3A cells. The test compound did not produce any decreased cell viability, DNA damage, chromosomal mutations, cell cycle changes, or apoptotic effects in the tested cells. Additionally, RT-qPCR analysis revealed the downregulation of CYP3A4 (metabolism), M-TOR (cell death), and CDKN1A (cell cycle) genes. Under the experimental conditions used, the 2B compound did not show cytogenotoxic activity after a single exposure to HepG2/C3A human cells.

Cytokinesis-Blocking Micronucleus Assay for Assessing Nuclear Chromatin Integrity Abnormalities in Dog's Somatic Cells After Exposure to HVAD-Produced Silver Nanoparticles

The widespread use of silver nanoparticles in many industries is increasing every year. Along with this use, there is growing concern about the potential unintentional exposure of human and animal organisms to these nanomaterials. It has been shown that AgNPs have the ability to penetrate organisms and can have harmful effects on cells and organs in the body. In order to reduce the effects of AgNPs on living organisms, newer solutions are being investigated, such as particle stabilization or other methods of synthesizing these particles. The physical synthesis of AgNPs using high-voltage arc discharge (HVAD) may be one of these alternatives. To determine the effect of silver nanoparticles obtained by this method, cytogenetic analysis was performed on domestic dog somatic cells using a cytokinesis-blocking micronucleus assay. In the experiments performed, peripheral blood cells of the domestic dog were exposed in vitro for 3 and 24 h to three tested colloidal silver compounds (unstable AgNP-HVAD, sodium citrate-stabilized silver nanoparticles-AgNP+C, and silver nitrate). The toxicity of these compounds was evaluated at concentrations of 5, 10, and 20 µg/L, and the presence of the following cellular abnormalities was analyzed: micronuclei, nuclear buds, nucleoplasmic bridges, or multinucleated cells. The study showed a significant increase in the number of micronuclei compared to the control sample, as well as the presence of nuclear buds and nucleoplasmic bridges in somatic cells of the domestic dog, confirming the genotoxic nature of the particles. However, there was no cytotoxic effect due to the lower number of multinucleated cells and the absence of apoptotic or necrotic cells in the samples analyzed. Further studies are needed to better understand the mechanisms of toxicity of AgNPs produced by the HVAD method and the extent of their effects on mammalian somatic cells.

Novelties on tradescantia: Perspectives on water quality monitoring

In the face of intense urban expansion, the assessment of water quality plays a crucial role in environmental preservation. Here, we evaluated aquatic genotoxicity in three locations with different degrees of urbanization using Tradescantia pallida var. purpurea and Daphnia magna as bioindicators. The objective was to investigate the influence of urbanization on water quality and the efficiency of the TRAD-MCN biological test in monitoring aquatic genotoxicity. Therefore, we established the genotoxic potential by evaluating micronucleus frequency in T. pallida and immobilization and DNA damage in the standard test with D. magna during two seasons of the year (dry and rainy). Our results showed that the frequency of micronuclei in T. pallida (TRAD-MCN) was significantly higher in the locations with a higher degree of urbanization, independently of the seasons. The tests with D. magna revealed a higher rate of immobilization and DNA damage in the location most impacted by residential and industrial effluents (especially mining activities). Additionally, the TRAD-MCN proved to be equivalent to the standard test for genotoxicity assessment, supporting its potential applicability in environmental monitoring. Finally, we observed that urbanization significantly influences water quality, and among the evaluated physicochemical parameters, dissolved oxygen was shown to be the most important driver of the water quality index (WQI). Our findings have significant implications for water resource management, underlining the need for policies that consider the specificities of different regions. This highlights the robustness, flexibility, and reliability of T. pallida as an environmental monitoring tool.

Nuclear abnormalities and DNA damage indicate different genotoxic stress responses of marsh frogs (Pelophylax ridibundus, Pallas 1771) to industrial and agricultural water pollution in South Bulgaria

Amphibians are continuously exposed to pollutants and anthropogenic stressors in their natural habitats, representing a significant challenge to their survival. This study aimed to quantify the extent of DNA damage caused by chronic industrial and agrochemical surface water pollution in wild populations of the marsh frog (Pelophylax ridibundus). The observed genotoxic effects on the marsh frog DNA, manifesting as abnormalities in erythrocyte nuclei, micronuclei, and DNA strand breaks, demonstrate a clear cause-and-effect relationship with surface water parameters, heavy metals, metalloids, and pesticides. The most prevalent nuclear abnormalities observed were notched and blebbed nuclei and nuclear buds, indicative of chromosomal instability. The significant correlation between cadmium, lead, and copper contamination and the increased frequency of DNA breakage in the marsh frogs from the industrial site indicates that heavy metal contamination has a higher genotoxic potential than pesticide contamination. These findings underscore the vulnerability of amphibians inhabiting heavy metal-contaminated wetlands to genotoxic stress due to their lower tolerance to environmental genotoxins. Therefore, using in situ assays to detect erythrocyte nuclear abnormalities and DNA damage in P. ridibundus could serve as a reliable indicator of environmental quality and provide early detection of anthropogenic pollution.

Accelerated Aging Effects Observed In Vitro after an Exposure to Gamma-Rays Delivered at Very Low and Continuous Dose-Rate Equivalent to 1-5 Weeks in International Space Station

Radiation impacting astronauts in their spacecraft come from a "bath" of high-energy rays (0.1-0.5 mGy per mission day) that reaches deep tissues like the heart and bones and a "stochastic rain" of low-energy particles from the shielding and impacting surface tissues like skin and lenses. However, these two components cannot be reproduced on Earth together. The MarsSimulator facility (Toulouse University, France) emits, thanks to a bag containing thorium salts, a continuous exposure of 120 mSv/y, corresponding to that prevailing in the International Space Station (ISS). By using immunofluorescence, we assessed DNA double-strand breaks (DSB) induced by 1-5 weeks exposure in ISS of human tissues evoked above, identified at risk for space exploration. All the tissues tested elicited DSBs that accumulated proportionally to the dose at a tissue-dependent rate (about 40 DSB/Gy for skin, 3 times more for lens). For the lens, bones, and radiosensitive skin cells tested, perinuclear localization of phosphorylated forms of ataxia telangiectasia mutated protein (pATM) was observed during the 1st to 3rd week of exposure. Since pATM crowns were shown to reflect accelerated aging, these findings suggest that a low dose rate of 120 mSv/y may accelerate the senescence process of the tested tissues. A mathematical model of pATM crown formation and disappearance has been proposed. Further investigations are needed to document these results in order to better evaluate the risks related to space exploration.

Effects of blood metal(loid) concentrations on genomic damages in sharks

The use of effect biomarkers has contributed to the understanding of the sublethal effects of contaminants on different organisms. However, the analysis of genotoxic markers as an indicator of organism and environmental health in sharks is underexplored. Thus, the present study investigated the relationship between the genomic damage frequency in erythrocytes and metal(loid) concentrations in whole blood of three shark species (Galeocerdo cuvier, Negaprion brevirostris and Ginglymostoma cirratum), taking into account climatic seasonality. The results showed that G. cuvier, an apex predator, presented the highest total erythrocyte genomic damage frequencies together with the highest mean whole blood concentrations of Al, Cd, Cr, Fe, Mn, Ni, Pb and Zn. The shark N. brevirostris also presented high levels of metal(loid), indicating a greater susceptibility to these contaminants in species that preferentially feed on fish. In contrast, G. cirratum, a mesopredator, presented the lowest erythrocyte damage frequencies and whole blood metal(loid) concentrations. The presence of micronuclei was the most responsive biomarker, and Al, As and Zn had an important effect on the genomic damage frequencies for all species evaluated. Zn concentration influenced the binucleated cells frequencies and Al concentration had an effect on the total damage and micronuclei frequencies in G. cuvier and N. brevirostris. Binucleated cells and blebbed nuclei frequencies were affected by As concentration, especially in G. cirratum, while showing a strong and positive correlation with most of the metals analyzed. Nonetheless, baseline levels of metal(loid) blood concentrations and erythrocyte genomic damage frequencies in sharks have not yet been established. Therefore, minimum risk levels of blood contaminants concentrations on the health of these animals have also not been determined. However, the high genomic instability observed in sharks is of concern considering the current health status of these animals, as well as the quality of the environment studied.

In Vitro and In Vivo Genotoxicity of Polystyrene Microplastics: Evaluation of a Possible Synergistic Action with Bisphenol A

The ubiquitous presence of plastics represents a global threat for all ecosystems and human health. In this study, we evaluated, in vitro and in vivo, the genotoxic potential of different concentrations of polystyrene microplastics (PS-MPs) and their possible synergistic interactions with bisphenol-A (BPA). For the in vitro and the in vivo assays, we used human lymphocytes and hemocytes from Lymnaea stagnalis, respectively. The genomic damage was evaluated by the micronucleus assay, and differences in eggs laid and growth of L. stagnalis were also evaluated. In human lymphocytes, PS-MPs alone at the concentration of 200 μg/mL and in association with BPA 0.100 µg/mL significantly increased the frequencies of micronuclei and nuclear buds, indicating a possible in vitro genotoxic additive action of these two compounds. Vice versa, PS-MPs did not result in genotoxicity in hemocytes. Our results indicated that PS-MPs have genotoxic properties only in vitro and at a concentration of 200 µg/mL; moreover, this compound could intensify the genomic damage when tested with BPA, indicating possible cumulative effects. Finally, PS significantly reduced the growth and the number of laid eggs in L. stagnalis.

Chemical transformation of the multibudding yeast, Aureobasidium pullulans

Aureobasidium pullulans is a ubiquitous polymorphic black yeast with industrial and agricultural applications. It has recently gained attention amongst cell biologists for its unconventional mode of proliferation in which multinucleate yeast cells make multiple buds within a single cell cycle. Here, we combine a chemical transformation method with genome-targeted homologous recombination to yield ∼60 transformants/μg of DNA in just 3 days. This protocol is simple, inexpensive, and requires no specialized equipment. We also describe vectors with codon-optimized green and red fluorescent proteins for A. pullulans and use these tools to explore novel cell biology. Quantitative imaging of a strain expressing cytosolic and nuclear markers showed that although the nuclear number varies considerably among cells of similar volume, total nuclear volume scales with cell volume over an impressive 70-fold size range. The protocols and tools described here expand the toolkit for A. pullulans biologists and will help researchers address the many other puzzles posed by this polyextremotolerant and morphologically plastic organism.

Toxicity assessment of powdered laundry detergents: an in vivo approach with a plant-based bioassay

Powdered laundry detergents, encompassing a diverse blend of organic and inorganic compounds, are crucial in efficiently removing dirt in household cleaning. This study investigated the cytotoxic and genotoxic potential of commonly used powdered laundry detergents in Sri Lanka using the Allium cepa bioassay. Five detergents (four branded A, B, C, and D, and one non-branded E) were selected for assessment. Toxicity evaluations were conducted across a range of predetermined aqueous detergent concentrations (0-2500 mg/L) using the A. cepa bioassay, with all experiments being triplicated and following standard protocols. Exposure to detergent concentrations up to 500 mg/L resulted in mitosis suppression, nuclear aberrations, and chromosomal abnormalities in A. cepa, indicating concentration-dependent cytotoxicity and genotoxicity. Condensed nuclei were notably prevalent among nuclear abnormalities, while vagrant chromosomes and chromosomal adherence were the most frequent chromosomal aberrations observed. At higher concentrations (> 500 mg/L), the selected detergents induced necrotic cell death in A. cepa root meristematic cells. This study warns to avoid the unnecessary use of detergents as they cause significant ecological risks and advocates for further research to comprehensively assess detergent toxicity across diverse organisms within ecosystems to safeguard ecosystem health effectively.

Study of Radiosensitivity and Induction of Radiation Adaptive Response in Peripheral Blood Lymphocytes of Patients with Oncological Diseases Using the Micronuclear Test

Radiosensitivity to low and medium doses of X-ray radiation and the ability to induce a radiation adaptive response (RAR) of lymphocytes during in vitro irradiation of peripheral blood of patients with cancer were studied. The criterion for cytogenetic damage was the frequency of micronuclei (MN) in cytochalasin-blocked binucleate lymphocytes in culture. It was found that the spontaneous level of cytogenetic damage in the lymphocytes of patients was 2.6 times higher than in healthy volunteers, and there was also significant interindividual variability in values compared to the control cohort. There were no differences in mean values for radiosensitivity to low and medium doses of X-ray between the study groups. There was no correlation between the spontaneous level of MN in lymphocytes and the radiosensitivity of individuals in both groups. RAR was induced with the same frequency and to the same extent in lymphocytes from both patients and healthy individuals.

Prediction of radiotherapy toxicity: 20 years of COPERNIC radiosensitivity diagnosis procedure

PURPOSE

Since 2004, in the frame of the care pathway, our Research Unit has replied to the demand of expertise of radiation oncologists about the individual radiosensitivity of some of their patients. This procedure, called COPERNIC, is based on a skin biopsy and the radiation-induced nucleoshuttling of the ATM protein (the RIANS model), a major actor of DNA break repair and signaling. In 2016, with the first 117COPERNIC fibroblast lines, we obtained a significant correlation between the maximum number of the nuclear ATM foci, pATMmax, and the CTCAE severity grade of the post-radiotherapy tissue reactions. In this study, we propose to verify the validity of our previous findings with a new COPERNIC data subset obtained in the 2014-2024 period.

MATERIALS AND METHODS

We applied a standard immunofluorescence technique to quiescent COPERNIC fibroblasts to assess, after 2Gy, the level of micronuclei, γH2AX and pATM foci. The 117 COPERNIC data published in 2016 were considered as the reference data subset. A new COPERNIC data subset composed of 133fibroblast cell lines was considered as the validating data subset.

RESULTS

Our data showed that spontaneous or residual micronuclei levels, and residual γH2AX foci levels cannot predict CTCAE grades. Conversely, the linear formula linking the maximal number of pATM foci and the corresponding CTCAE grade and obtained in 2016 from the reference data subset fitted well the validating data.

CONCLUSIONS

The maximal number of pATM foci appears to be one of the most reliable biomarkers for predicting post-radiotherapy radiotoxicity.

Isolation and comparative genotoxicity screening of trichokonins VI and VIII on CHO-K1 cells

Peptaibols are fungal peptides that exhibit efficacy against pathogen microorganisms. Trichokonin VI (TK-VI) and trichokonin VIII (TK-VIII) are known peptaibols isolated from the endolichenic fungi Hypocrea sp. Previous investigations reported that trichokonin VI presents antiproliferative effects on tumor cells. This study is pioneering in elucidating the genotoxic effects of TK-VI and TK-VIII, contributing to the thorough assessment of their safety as potential therapeutic agents. The present investigation aimed to evaluate the genotoxicity of TK-VI and TK-VIII on CHO-K1 cells. Cytotoxicity was evaluated using the XTT assay and clonogenic survival assays, followed by evaluation of DNA damage using the comet assay and micronucleus test conducted in vitro. The XTT assay results indicated IC50 values of 10.30 µM and 9.89 µM for TK-VI and TK-VIII, respectively. The clonogenic survival assay indicated that concentrations of 10 µM or higher completely inhibited the cell colony formation. In the comet assay, both TK-VI and TK-VIII increased the DNA damage score and the frequency of comet nuclei in all tested concentrations. In the micronucleus assay, TK-VI and TK-VIII at 10 µM increased the frequency of MN in CHO-K1 cells. Both TK-VI and TK-VIII exhibited genotoxic effects. Our findings underscore the importance of considering the genotoxicological safety of peptaibols, particularly when assessing their potential for other biological activities.

Biological potential, chemical profiling, and molecular docking study of Morus alba L. extracts

Morus alba L. is a plant with a long history of dietary and medicinal uses. We hypothesized that M. alba possesses a significant biological potential. In that sense, we aimed to generate the chemical, antimicrobial, toxicological, and molecular profile of M. alba leaf and fruit extracts. Our results showed that extracts were rich in vitamin C, phenols, and flavonoids, with quercetin and pterostilbene concentrated in the leaf, while fisetin, hesperidin, resveratrol, and luteolin were detected in fruit. Extracts exhibited antimicrobial activity against all tested bacteria, including multidrug-resistant strains. The widest inhibition zones were in Staphylococcus aureus ATCC 33591. The values of the minimum inhibitory concentration ranged from 15.62 μg/ml in Enterococcus faecalis to 500 μg/ml in several bacteria. Minimum bactericidal concentration ranged from 31.25 μg/ml to 1000 μg/ml. Extracts impacted the biofilm formation in a concentration-dependent and species-specific manner. A significant difference in the frequency of nucleoplasmic bridges between the methanolic extract of fruit (0.5 μg/ml, 1 μg/ml, 2 μg/ml), as well as for the frequency of micronuclei between ethanolic extract of leaf (2 μg/ml) and the control group was observed. Molecular docking suggested that hesperidin possesses the highest binding affinity for multidrug efflux transporter AcrB and acyl-PBP2a from MRSA, as well as for the SARS-CoV-2 Mpro. This study, by complementing previous research in this field, gives new insights that could be of great value in obtaining a more comprehensive picture of the Morus alba L. bioactive potential, chemical composition, antimicrobial and toxicological features, as well as molecular profile.

A multi-biomarker micronucleus assay using imaging flow cytometry

Genetic toxicity testing assesses the potential of compounds to cause DNA damage. There are many genetic toxicology screening assays designed to assess the DNA damaging potential of chemicals in early drug development aiding the identification of promising drugs that have low-risk potential for causing genetic damage contributing to cancer risk in humans. Despite this, in vitro tests generate a high number of misleading positives, the consequences of which can lead to unnecessary animal testing and/or the abandonment of promising drug candidates. Understanding chemical Mode of Action (MoA) is vital to identifying the true genotoxic potential of substances and, therefore, the risk translation into the clinic. Here we demonstrate a simple, robust protocol for staining fixed, human-lymphoblast p53 proficient TK6 cells with antibodies against ɣH2AX, p53 and pH3S28 along with DRAQ5™ DNA staining that enables analysis of un-lysed cells via microscopy approaches such as imaging flow cytometry. Here, we used the Cytek® Amnis® ImageStream®X Mk II which provides a high-throughput acquisition platform with the sensitivity of flow cytometry and spatial morphological information associated with microscopy. Using the ImageStream manufacturer's software (IDEAS® 6.2), a masking strategy was developed to automatically detect and quantify micronucleus events (MN) and characterise biomarker populations. The gating strategy developed enables the generation of a template capable of automatically batch processing data files quantifying cell-cycle, MN, ɣH2AX, p53 and pH3 populations simultaneously. In this way, we demonstrate how a multiplex system enables DNA damage assessment alongside MN identification using un-lysed cells on the imaging flow cytometry platform. As a proof-of-concept, we use the tool chemicals carbendazim and methyl methanesulphonate (MMS) to demonstrate the assay's ability to correctly identify clastogenic or aneugenic MoAs using the biomarker profiles established.

Multiparameter imaging flow cytometry-based cytokinesis-block micronucleus assay: Reduction of culture time and blood volume for improved efficiency

In the event of a large-scale incident involving radiological or nuclear exposures, there is a potential for large numbers of individuals to have received doses of radiation sufficient to cause adverse health effects. It is imperative to quickly identify these individuals in order to provide information to the medical community to assist in making decisions about their treatment. The cytokinesis-block micronucleus assay is a well-established method for performing biodosimetry. This assay has previously been adapted to imaging flow cytometry and has been validated as a high-throughput option for providing dose estimates in the range of 0-10 Gy. The goal of this study was to test the ability to further optimize the assay by reducing the time of culture to 48 h from 68 h as well as reducing the volume of blood required for the analysis to 200 μL from 2 mL. These modifications would provide efficiencies in time and ease of processing impacting the ability to manage large numbers of samples and provide dose estimates in a timely manner. Results demonstrated that either the blood volume or the culture time could be reduced while maintaining dose estimates with sufficient accuracy for triage analysis. Reducing both the blood volume and culture time, however, resulted in poor dose estimates. In conclusion, depending on the needs of the scenario, either culture time or the blood volume could be reduced to improve the efficiency of analysis for mass casualty scenarios.

Cytogenotoxic screening of the natural compound niga-ichigoside F1 from Rubus imperialis (Rosaceae)

Rubus imperialis Chum. Schl. (Rosaceae) have demonstrated some pharmacological activities, including gastroprotective action. However, genotoxic effects of R. imperialis extract was also reported. Since niga-ichigoside F1 (NIF1) is a major compound of this plant species, and which has proven pharmacological properties, it is essential to investigate whether this compound is responsible for the observed toxicity. Therefore, the objective of this study was to analyze the effects of NIF1 on HepG2/C3A cells for possible cytogenotoxicity, cell cycle and apoptosis influence, and expression of genes linked to the DNA damage, cell cycle, cell death, and xenobiotic metabolism. The results showed no cytogenotoxic effects of NIF1 at concentrations between 0.1 and 20 μg/ml. Flow cytometry also showed no cell cycle or apoptosis disturbance. In the gene expression analysis, none of the seven genes investigated showed altered expression. The data indicate that NIF1 has no cytogenotoxic effects, and no interruption of the cell cycle, or induction of apoptosis, apparently not being responsible for the cytotoxic effects observed in the crude extract of R. imperialis.

The increased chromosomal DNA damage in patients with Familial Mediterranean Fever

Familial Mediterranean Fever (FMF) is an inherited autoinflammatory disease. In this study, we aimed to assess chromosomal DNA damage and cell proliferation by using cytokinesis-block micronucleus cytome (CBMN-cyt) assay in the peripheral blood lymphocytes of untreated FMF patients carrying M694V and R202Q mutations, which are the most common MEFV gene mutations in Turkish society. The study included 20 untreated FMF patients with M694V and R202Q mutations and 20 healthy individuals of similar age and sex as the control group. Micronucleus (MN), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) were scored in the obtained bi-nucleated (BN) cells. Additionally, the nuclear division index (NDI) was calculated using the scores of mononuclear, binuclear, and multinuclear cells. We found that MN and NPBs frequencies in FMF patients were significantly higher than in controls, and number of metaphases was significantly lower (respectively, p < 0.05, p < 0.01, and p < 0.01). However, there was no significant difference in NBUDs frequencies and NDI values between FMF patients and controls (p > 0.05). Our study is the first to evaluate FMF patients' lymphocytes using the CBMN-cyt assay, as no previous research has been found in this respect. Increased MN and NPB frequencies may be useful as biomarkers for chromosomal DNA damage, and may indicate a potential for elevated cancer risk in untreated FMF patients.

The effects of iodine 131 treatment on chromosomal and oxidative DNA damage in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is a common endocrine cancer with a good prognosis. Radioactive iodine is thought to be useful for individuals who have had a total or almost total thyroidectomy, but its effects are still controversial. The effects of radioactive iodine-131 (I-131) treatment on oxidative and chromosomal damage in PTC patients were examined in this study, which was carried out with 16 patients newly diagnosed with PTC and 20 healthy control subjects with similar age and gender. Blood samples were taken from patients with PTC at five sampling times (before total thyroidectomy, after total thyroidectomy, and seven days, six months, and one year after treatment) and from control subjects. The cytokinesis block micronucleus cytome (CBMN-cyt) assay parameters in peripheral blood lymphocytes of patients with PTC and controls were evaluated and plasma 8-hydroxydeoxyguanosine (8-OHdG) levels were measured. Furthermore, genome instability and oxidative DNA damage in peripheral blood lymphocytes and plasma of patients with PTC were evaluated before total thyroidectomy (n=16), after total thyroidectomy (before I-131 treatment) (n=16), seven days (n=10), six months (n=5), and one year after treatment (n=5). The numbers of CBMN-cyt assay parameters (micronucleus; MN and nucleoplasmic bridges; NPB) and 8-OHdG levels in patients with PTC were determined to be significantly higher than in those of the control subjects and these values significantly decreased after total thyroidectomy (before I-131 treatment). While the number of MN, apoptotic, and necrotic cells increased after I-131 treatment, it significantly decreased after six months and one year after treatment. The results achieved in this study suggest that I-131 treatment may pose a threat to cells and that radioactive iodine therapy should be avoided (if possible) for patients with PTC after total thyroidectomy.

Comparative study of integrated bio-responses in deep-sea and nearshore mussels upon abiotic condition changes: Insight into distinct regulation and adaptation

Deep-sea mussels, one of the dominant species in most deep-sea ecosystems, have long been used as model organisms to investigate the adaptations and symbiotic relationships of deep-sea macrofauna under laboratory conditions due to their ability to survive under atmospheric pressure. However, the impact of additional abiotic conditions beyond pressure, such as temperature and light, on their physiological characteristics remains unknown. In this study, deep-sea mussels (Gigantidas platifrons) from cold seep of the South China Sea, along with nearshore mussels (Mytilus coruscus) from the East China Sea, were reared in unfavorable abiotic conditions for up to 8 days. Integrated biochemical indexes including antioxidant defense, immune ability and energy metabolism were investigated in the gill and digestive gland, while cytotoxicity was determined in hemocytes of both types of mussels. The results revealed mild bio-responses in two types of mussels in the laboratory, represented by the effective antioxidant defense with constant total antioxidant capability level and malondialdehyde content. There were also disparate adaptations in deep-sea and nearshore mussels. In deep-sea mussels, significantly increased immune response and energy reservation were observed in gills, together with the elevated cytotoxicity in hemocytes, implying the more severe biological adaptation was required, mainly due to the symbiotic bacteria loss under laboratory conditions. On the contrary, insignificant biological responses were exhibited in nearshore mussels except for the increased energy consumption, indicating the trade-off strategy to use more energy to deal with potential stress. Overall, this comparative study highlights the basal bio-responses of deep-sea and nearshore mussels out of their native environments, providing evidence that short-term culture of both mussels under easily achievable laboratory conditions would not dramatically alter their biological status. This finding will assist in broadening the application of deep-sea mussels as model organism in future research regardless of the specialized research equipment.

Role of Oxidative Stress and DNA Damage on Preterm Birth Outcome

Background: Preterm birth (PTB) poses a significant global health challenge and focused research is vital for improving maternal and neonatal health outcomes. The purpose of this study was to determine the effect of oxidative stress (OS) and DNA damage on PTB. Methods: There were two groups: (a) cases consisting of mothers with PTB (<37 weeks of gestation, n = 100) and (b) controls consisting of mothers with term birth (>37 weeks of gestation, n = 100). Women with vaginal infection, non-cephalic presentation, multiple gestations, fetal anomalies, Cesarean delivery, pregnancy with Mullerian anomalies, or preeclampsia were excluded from the study. OS analysis was conducted by measuring levels of superoxide dismutase (SOD), catalase (CAT), lipid peroxidation (LPO), and total protein and DNA damage were evaluated by CBMN-Cyt assay. Statistical analysis was performed using students' t-test and one-way ANOVA. Results: Low levels of antioxidants SOD and CAT (p < .0001), and total protein (p < .0001), besides high malondialdehyde (byproduct of LPO) (p < .0001) were observed in the PTB group. Moreover, high frequencies of micronuclei (p < .0001) and nucleoplasmic buds (p < .01) were detected in the PTB mothers compared to term birth mothers, while no significance was observed in the nucleoplasmic bridge frequencies. Conclusion: When the body's immune system and antioxidants fail to cope up with the generated OS, it can lead to PTB. Along with other body tests, OS markers and CBMN-Cyt tests have the potential to be used in diagnostics for early warning as well as monitoring and advising mothers for a better pregnancy outcome.

Evaluation of oxidative damage and genotoxicity in populations exposed to arsenic in drinking water from Santa Fe province, Argentina

The presence of arsenic in the environment is a public health problem. Groundwater of certain regions of Argentina contains arsenic of natural origin in concentrations that exceed the guide level recommended by World Health Organization (WHO, 10 µg/L). Pathologies derived from chronic arsenic consumption justify the planning of human biomonitoring. Hence, the aim of this study was to evaluate oxidative damage and genotoxicity and its relationship with nutritional variables in populations exposed to arsenic through drinking water in Santa Fe province, Argentina. A total of 322 participants were analyzed for arsenic in urine together with biomarkers of genotoxicity (Comet assay in blood and frequency of Micronuclei and other Nuclear Abnormalities in exfoliated buccal cells) and oxidative stress (modified Comet assay with Endonuclease III, Lipid peroxidation and antioxidant enzyme activity), as well as nutritional and biochemical variables. Results showed that 45 % of participants excreted arsenic in the urine. Consumption of water with arsenic, whether currently or previously, was associated with statistically significant increase of oxidative DNA damage and lipid peroxidation. MN in exfoliated buccal cells serve as an early biomarker of genotoxicity and showed significant differences in the current exposed group. Biochemical results indicate dyslipidemias potentially linked to dietary choices, and insufficient intake of fruits and vegetables rich in antioxidants, was also noted. This study advocates risk communication to the population, educators, and health authorities, emphasizing the need for preventive health strategies and improved food education.

UVB-Aged Microplastics and Cellular Damage: An in Vitro Study

Plastics are synthetic organic compounds whose widespread use generates enormous waste. Different processes, such as mechanical abrasion, microbiological activity, and UVB irradiation, can fragment the plastic material and generate microplastics (MPs). MPs are ubiquitous, and various organisms, including humans, can ingest or inhale them, with potential adverse health effects. The differences between UV-aged and virgin particles were studied to evaluate the genotoxic damage and oxidative stress induced by polystyrene MPs with 1 and 5 µm sizes on the monocyte-like cell line (THP-1). Fourier transform infrared spectroscopy and Ζ-potential measurements were used to characterise MP particles after UVB exposure. Cells exposed to MPs show a widespread change in the cellular environment with the generation of reactive oxidative species (ROS), as indicated by the increased malondialdehyde level. The occurrence of genotoxic damage is correlated to the smaller size and ageing state of the MPs. The biochemical and genomic alterations observed in this in vitro study suggest that MPs, ubiquitous pollutants, following natural degradation and oxidation processes can cause various adverse effects on the health of the exposed population, making it necessary to carry out further studies to better define the real risk.

Can Salvinia auriculata bioremediate the toxic effects of Fipronil 800wg on the tadpoles of Dendropsophus minutus?

Worldwide, the indiscriminate and escalating application of pesticides has led to extensive impacts on both the environment and non-target organisms. Phytoremediation, which employs plants to decontaminate environments, is a potential strategy for the mitigation of this damage. The present study assessed the phytoremedial potential of Salvinia auriculata, an aquatic macrophyte known to be effective for the removal of environmental contaminants. In the laboratory, Dendropsophus minutus tadpoles were exposed to different concentrations (0.035, 0.1, 1.0, and 1.5 mg/l) of the commercial insecticide Fipronil 800wg in two treatments - (i) simple exposure for 96 h, and (ii) exposure for 168 h in aquariums containing S. auriculata. In the first experiment, a mortality rate of 33.3 % was recorded at the highest Fipronil concentration (1.5 mg/l), and genotoxic parameters increased at all concentrations except 0.035 mg/L, in comparison with the control. In the second experiment, phytoremediation occurred at all the concentrations tested, with lower frequencies of cells with micronuclei, and binucleated, anucleated, and pyknotic nuclei being observed, in comparison with the first experiment. These findings highlight the potential effectiveness of S. auriculata for the phytoremediation of environments contaminated by pesticides and contribute to the understanding of the benefits of this approach for the protection and preservation of aquatic biodiversity.

A multi-approach analysis of the toxicity of a commercial formulation of monensin on Rhinella arenarum embryos and larvae

Monensin, an antibacterial commonly used in animal fattening, can enter aquatic ecosystems and harm non-target organisms. Since there are no previous studies about the effects of monensin on amphibians, the aim of the present study was to evaluate the lethal and sublethal toxicity of a commercial formulation of monensin (CFM) through standardized bioassays with embryos and larvae of the amphibian Rhinella arenarum. Oxidative stress (catalase and glutathione S-transferase activities, and reduced glutathione and lipid peroxidation levels), cholinesterasic effect (acetylcholinesterase and butyrylcholinesterase activities) and mutagenicity (micronuclei frequency) biomarkers were evaluated. The CFM produced teratogenic effects, with a teratogenic index of 6.21. Embryos (504 h-LC50: 273.33 µg/L) were more sensitive than larvae, as no significant mortality was observed on larvae exposed up to 3000 µg/L for 504 h. However, oxidative stress, cholinesterasic effect and mutagenicity biomarkers were altered on larvae exposed for 96 h to environmentally relevant concentrations (4, 12 and 20 µg/L of monensin active ingredient). The CFM caused adverse effects on the exposed organisms, primarily on embryos, leading to lethal and sublethal effects, which could impact the wildlife when it reaches aquatic ecosystems.

Safety assessment of high fructose corn syrup and fructose used as sweeteners in foods

High Fructose Corn Syrup (HFCS) and Fructose (FR) are widely used sweeteners in many foods and beverages. This study aimed at investigating the cytotoxic effects of HFCS (5%-30%) and FR (62.5-2000 μg/mL) using MTT assay in Human Hepatocellular Carcinoma (HepG2) cells, and genotoxic effects of using Chromosome Aberrations (CAs), Sister Chromatid Exchanges (SCEs), Micronuclei (MN) and comet assays in human lymphocytes. HFCS significantly reduced the cell viability in HepG2 cells at between 7.5% and 30% for 24 and 48 h. 30% HFCS caused a very significant toxic effect. FR had a cytotoxic effect in HepG2 cells at all treatments. However, as fructose concentration decreased, the cell viability decreased. HFCS (10%-20%) and FR (250-2000 μg/mL) decreased the mitotic index at higher concentrations. IC50 value was found to be a 15% for 48 h. IC50 value of FR was detected as 62.5 μg/mL for 24 h and 48 h. HFCS significantly increased CAs frequency at 15% and 20%. FR significantly increased the frequency of CAs at 250, 1000, and 2000 μg/mL for 48 h. Both sweeteners increased the frequency of SCEs at all concentrations. HFCS (15% and 20%) and FR (250, 1000, and 2000 μg/mL) induced MN frequency at higher concentrations. HFCS caused DNA damage in comet assay at 10% -30%. FR increased tail intensity and moment at 125-2000 μg/mL and tail length at 62.5, 250 and 500 μg/mL. Therefore, HFCS and FR are clearly seen to be cytotoxic and genotoxic, especially at higher concentrations.

Aqueous sage leave extract attenuates inflammation and oxidant-induced genotoxicity in human peripheral blood mononuclear cells

Traditional medicine has used sage (Salvia officinalis L.) preparations for centuries to prevent and treat various inflammatory and oxidative stress-induced conditions. The aim of this in vitro study was to determine the bioactive properties of a sage leave extract obtained with environmentally friendly aqueous extraction and lyophilisation in primary human peripheral blood cells. To that end we measured the total phenolic and flavonoid content (TPC and TFC, respectively) with gas chromatography-mass spectrometry (GC-MS). Non-cytotoxic concentrations determined with the trypan blue assay were used to assess the antioxidant (DPPH, ABTS, and PAB assay), antigenotoxic (CBMN assay), immunomodulatory (IL-1β and TNF-α), and neuroprotective effects (AChE inhibition). The extract contained high TPC (162 mg GAE/g of dry extract) and TFC (39.47 mg QE/g of dry extract) concentrations, while β-thujone content was unexpectedly low (below 0.9 %). Strong radical-scavenging activity combined with glutathione reductase activation led to a decrease in basal and H2O2-induced oxidative stress and DNA damage. A decrease in TNF-α and increase in IL-1β levels suggest complex immunomodulatory response that could contribute to antioxidant and, together with mild AChE inhibition, neuroprotective effects. Overall, this study has demonstrated that aqueous sage leave extract reduces the levels of thujone, 1,8-cineole, pinene, and terpene ketones that could be toxic in high concentrations, while maintaining high concentrations of biologically active protective compounds which have a potential to prevent and/or treat inflammatory and oxidative stress-related conditions.

Genotoxicity of Formaldehyde: Effect of Whole-Body Exposure on Polychromatic Erythrocyte/Normochromatic Erythrocyte Ratio in Male and Female Rats

Every day, millions of individuals are exposed to formaldehyde (FA) due to its extensive presence and versatile use. Many in vivoand in vitroexperiments revealed that the mechanism of genotoxicity induced by FA exposure is complex yet toxicity upon whole-body exposure (WBE) to FA is less. As teachers, students, and skilled assistants in the health care sectors are also extensively exposed to FA vapors, it might result in genotoxicity. However, the effects of subchronic exposure to FA at low concentrations are not clear. Hence, analysis of the micronucleus (MN) was necessary to study the genetic toxicity triggered by FA in the bone marrow of male and female experimental rats. The present study is a gender- and duration of exposure-based assessment of the geno- and cytotoxicity in bone marrow cells of Wistar rats to study the effect of WBE to 10% FA on polychromatic erythrocytes/normochromatic erythrocytes (PCE/NCE) ratio and micronucleated polychromatic erythrocytes (MnPCE) in experimental rats. The obtained result clearly showed that WBE to FA for 60 days at concentrations between 1 and 1.1 ppm (0, 1, and 1.5 h) induced genotoxic effects in both male and female rats by altering the MnPCE% and significantly increasing the ratio of PCE/NCE (1.07 ± 0.23, 1.20 ± 0.20, 1.22 ± 0.14). The PCE/NCE ratio in male rats was lesser (0.98, 1.12, and 1.18) when compared with female rats (1.17, 1.29, and 1.26) with 0, 1, and 1.5 h exposure, respectively. Thus, the genetic/cellular sensitivity to FA differs among the sexes and also depends on the exposure duration.

Cellular and Genomic Instability Induced by the Herbicide Glufosinate-Ammonium: An In Vitro and In Vivo Approach

Glufosinate-ammonium (GLA), an organophosphate herbicide, is released at high concentrations in the environment, leading to concerns over its potential genotoxic effects. However, few articles are available in the literature reporting the possible cellular and nuclear effects of this compound. We assessed, by in vitro and in vivo micronucleus assays, the genotoxicity of GLA on cultured human lymphocytes and Lymnaea stagnalis hemocytes at six concentrations: 0.010 (the established acceptable daily intake value), 0.020, 0.050, 0.100, 0.200, and 0.500 µg/mL. In human lymphocytes, our results reveal a significant and concentration-dependent increase in micronuclei frequency at concentrations from 0.100 to 0.500 μg/mL, while in L. stagnalis hemocytes, significant differences were found at 0.200 and 0.500 μg/mL. A significant reduction in the proliferation index was observed at all tested concentrations, with the only exception of 0.010 μg/mL, indicating that the exposure to GLA could lead to increased cytotoxic effects. In L. stagnalis, a significant reduction in laid eggs and body growth was also observed at all concentrations. In conclusion, we provided evidence of the genomic and cellular damage induced by GLA on both cultured human lymphocytes and a model organism's hemocytes; in addition, we also demonstrated its effects on cell proliferation and reproductive health in L. stagnalis.

Sampling, composition, and biological effects of Mexico City airborne particulate matter from multiple periods

Air pollution is a worldwide environmental problem with an impact on human health. Particulate matter of ten micrometers or less aerodynamic diameter (PM10) as well as its fine fraction (PM2.5) is related to multiple pulmonary diseases. The impact of air pollution in Mexico City, and importantly, particulate matter has been studied and considered as a risk factor for two decades ago. Previous studies have reported the composition of Mexico City particulate matter, as well as the biological effects induced by this material. However, material collected and used in previous studies is a limited resource, and sampling and particle recovery techniques have been improved. In this study, we describe the methods used in our laboratory for Mexico City airborne particulate matter PM10 and PM2.5 sampling, considering the years 2017, 2018 and 2019. We also analyzed the PM10 and PM2.5 samples obtained to determine their composition. Finally, we exposed lung cell line cultures to PM10 and PM2.5 to evaluate the biological effect of the material in terms of cell viability, cell death, inflammatory response, and cytogenetic alterations. Our results showed that PM10 composition includes inorganic, organic and biological compounds, while PM2.5 is a mixture of more enriched organic compounds. PM10 and PM2.5 treatment in lung cells does not significantly impact cell viability/cell death. However, PM10 and PM2.5 increase the secretion levels of IL-6. Moreover, PM10 as well as PM2.5 induce cytogenetic alterations, such as micronuclei, anaphase bridges, trinucleated cells and apoptotic cells in lung cells. Our results update the evidence of the composition and biological effects of Mexico City particulate matter and provide us a reliable basis for future approaches.

Hematological and genotoxic biomarkers in a natural population of freshwater turtles Trachemys dorbigni (Duméril & Bibron, 1835) (Testudines: Emydidae) living in an urban area in Southern Brazil

The present study aimed to report the morphometric and hematological indices and genotoxicity of a free-life population of D'Orbigny's slider turtles (Trachemys dorbigni) living in an urban area in Southern Brazil. For that, 16 specimens were randomly captured in an urban canal that receives irregular releases of wastewater. Biometrics and external visual changes were analyzed, such as turtle shell deformities, and the presence of parasites. Blood samples were collected to evaluate the hematological profile and the presence of micronuclei and other erythrocyte nuclear abnormalities as potential mutagenic and genotoxic effects. Water physicochemical parameters were also measured. Organisms with ectoparasites (31.25%) and small carapace deformations (56.25%) were observed, but maximum carapace length and weight were considered normal for the species according to the literature. The blood profile indicated low hemoglobin and hematocrit and a high number of total leukocytes, particularly eosinophils which characterize parasitic infections. A frequency of 0.12% for the micronucleus was considered basal, but the frequency of other erythrocyte abnormalities was evident, mainly of blebbed nuclei (63.79%), indicating chromosomal damage in the early stage. The results of this study suggest that natural populations of chelonian inhabiting urbanized areas are impacted by anthropogenic activities in the surrounding environment. Furthermore, it provides comprehensive data which can serve as a comparative model for environmental monitoring studies involving turtles.

Elucidation of the cytogenotoxic potential of vigabatrin and its in silico computer-assisted DNA interaction

Vigabatrin (VGB) is a gammaaminobutyric acid-ergic (GABA-ergic) antiepileptic drug (AED) and is one of 2 approved drugs available to treat infantile spasms (IS). The aim of this study is to elucidate conflicting data on the toxic effects of VGB and to obtain detailed information about its possible cytogenotoxic effects in human lymphocytes. For this purpose, in vitro Chromosomal Aberration (CA), Sister Chromatid Exchange (SCE), Micronucleus (MN) tests, and Comet Assay were performed to determine possible genotoxic and cytotoxic effects of VGB. In addition, the binding energy level of VGB to DNA was determined in silico by molecular docking. The highest concentration (80 μg/ml) of VGB increased the SCE, CA, MN and micronucleated binuclear cell (BNMN) frequency significantly compared to the control after 24 and 48 hours of treatment. In the tail density and tail length parameters, the dose-dependent increase was found to be statistically significant compared to the control. At the 40 and 80 μg/ml concentrations of VGB for 48 hours caused a statistically significant increase in both CA/Cell and AC percentages, while MI and NDI decreased only significantly at the highest concentration (80 µg/ml) causing. In the Comet Assay head density, tail density and tail length parameters, the dose-dependent increase was found to be statistically significant compared to the control. Also, the in silico molecular docking analysis showed that VGB interacts with B-DNA close to the threshold binding energy. The lowest negative free binding energy (ΔG binding) was found as -5.13 kcal/mol. In conclusion, all results are evaluated together, it has been determined that VGB has cytogenotoxic effects in vitro and binds to DNA in silico with significant free binding energy.

Chemical and genotoxic characterization of bioaccessible fractions as a comprehensive in vitro tool in assessing the health risk due to dust-bound contaminant ingestion

In the last two decades, awareness grew on the matter of the impact of environment on human health. Contaminants sorbed onto soil and settled dust can be ingested and thus represent a hazard, particularly to young children, who play on the ground and bring their hands and objects to their mouth. Metal(loid)s and polycyclic aromatic hydrocarbons (PAHs) are of concern as they are both carcinogenic to humans and ubiquitous in outdoor environments. The present study aims to assess the total and bioaccessible fractions of PAHs and metal(loid)s present in settled dust of four preschools located in industrial, urban, and suburban areas. On the one hand, children's incremental life cancer risks (ILCR) were calculated according to ingestion pathway. On the other hand, the genotoxicities of the bioaccessible dust-bonded contaminants were determined on gastric cells. PAH concentrations ranged from 50.9 to 2267.3 ng/g, and the bioaccessible fraction represented 10.7% of the total in average. Metal(loid) concentration ranged from 12,430 to 38,941 µg/g, and the mean bioaccessibility was of 40.1%. Cancer risk ranged from 2.8.105 to 8.6.105, indicating that there is a potential cancer risk for children linked to the ingestion of settled dust. The inorganic bioaccessible fraction induced little DNA (< 20%TailDNA) and chromosomal damages (30% increase in micronuclei), whereas the organic bioaccessible fraction induced higher DNA (17-63%TailDNA) and chromosomal damages (88% increase in micronuclei). Such experimental approach needs to be deepen, as a tool complementary to cancer risk calculation, since the latter only lays on a set of targeted contaminants with known toxicity values.

The use of effect biomarkers in chemical mixtures risk assessment - Are they still important?

Human epidemiological studies with biomarkers of effect play an invaluable role in identifying health effects with chemical exposures and in disease prevention. Effect biomarkers that measure genetic damage are potent tools to address the carcinogenic and/or mutagenic potential of chemical exposures, increasing confidence in regulatory risk assessment decision-making processes. The micronucleus (MN) test is recognized as one of the most successful and reliable assays to assess genotoxic events, which are associated with exposures that may cause cancer. To move towards the next generation risk assessment is crucial to establish bridges between standard approaches, new approach methodologies (NAMs) and tools for increase the mechanistically-based biological plausibility in human studies, such as the adverse outcome pathways (AOPs) framework. This paper aims to highlight the still active role of MN as biomarker of effect in the evolution and applicability of new methods and approaches in human risk assessment, with the positive consequence, that the new methods provide a deeper knowledge of the mechanistically-based biology of these endpoints.

Evidence on the genotoxic and ecotoxic effects of PFOA, PFOS and their mixture on human lymphocytes and bacteria

Considering that the PFOA and PFOS are widely spread chemicals with harmful effects in human and environmental health as well as the increasing interest of the scientific community in the implications that might present especially when they co-exist, this study aims to assess their harmful impacts, both individually and as a mixture on human lymphocytes and aquatic microorganisms. The cytokinesis-block micronucleus (CBMN) assay was used to examine their potential for cytotoxicity and genotoxicity towards human cells, and Microtox assay using Aliivibrio fischeri assay was used to estimate the environmental risk. Regarding the human lymphocytes, the tested concentrations ranged between 250 and 1000 μg L-1, for all cases. PFOA increased slightly the frequency of micronuclei (MN) but without statistical significance. In the case of PFOS, our results showed a dose-dependent increase in the frequency of micronuclei which showed a statistically significant difference (p < 0.001) at 1000 μg L-1, which is the highest studied concentration. Regarding the CBPI index, statistically significant (p < 0.05, p < 0.01, and p < 0.001 respectively) differences were observed at all studied concentrations of PFOS, compared to the control. The mixture was found to be more cytotoxic and genotoxic than the individual tested compounds, causing a higher decrease at the CBPI index even in lower concentrations and increase at the MN frequencies. Aliivibrio fischeri was exposed to various concentrations in the range of 0.5 μg L-1- 20 mg L-1, for 5 and 15 min and significant increase in the inhibition percentage at the highest tested concentration of their mixture after 15 min was observed.