The in vitro micronucleus technique

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.

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.

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.

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.

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.

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.

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.

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.

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.

Genotoxicity of Gamma Radiation Against Lymphocytes of Radiation Workers: The Cytokinesis-Block Micronucleus Assay

<b>Background and Objective:</b> Gamma irradiation induces genotoxicity, characterized by the formation of extra-nuclear bodies and left behind during the anaphase stage of cell division, often referred to as a micronucleus (MN). The present work aims to monitor exposure to ionizing radiation as a genotoxic agent in the lymphocytes of workers at radiation energy centers. <b>Materials and Methods:</b> The lymphocyte cytokinesis block micronucleus assay used and analyzed the correlation between the Nuclear Division Index (NDI), age, blood type and the number of micronuclei (MN). Blood samples were collected from 20 volunteers in heparin tubes, exposed to 2 Gy gamma rays and cultured <i>in vitro</i>. <b>Results:</b> A significant difference in the number of micronuclei between blood group A and blood groups A, B and AB. The Nuclear Division Index (NDI) value for lymphocytes of radiation energy center workers after gamma radiation was significant (1.74±0.1) but still within the normal range. Neither MN frequency nor NDI values correlated with age, but MN frequency showed a correlation with blood type. <b>Conclusion:</b> The gamma irradiation did not induce a cytostatic effect but proved genotoxic to the lymphocytes of radiation energy center workers. Notably, blood type A demonstrated higher sensitivity to gamma radiation.

Redox-activity and in vitro effects of regional atmospheric aerosol pollution: Seasonal differences and correlation between oxidative potential and in vitro toxicity of PM1

Particulate Matter (PM) is a complex and heterogeneous mixture of atmospheric particles recognized as a threat to human health. Oxidative Potential (OP) measurement is a promising and integrative method for estimating PM-induced health impacts since it is recognized as more closely associated with adverse health effects than ordinarily used PM mass concentrations. OP measurements could be introduced in the air quality monitoring, along with the parameters currently evaluated. PM deposition in the lungs induces oxidative stress, inflammation, and DNA damage. The study aimed to compare the OP measurements with toxicological effects on BEAS-2B and THP-1 cells of winter and summer PM1 collected in the Po Valley (Italy) during 2021. PM1 was extracted in deionized water by mechanical agitation and tested for OP and, in parallel, used to treat cells. Cytotoxicity, genotoxicity, oxidative stress, and inflammatory responses were assessed by MTT test, DCFH-DA assay, micronucleus, γ-H2AX, comet assay modified with endonucleases, ELISA, and Real-Time PCR. The evaluation of OP was performed by applying three different assays: dithiothreitol (OPDTT), ascorbic acid (OPAA), and 2',7'-dichlorofluorescein (OPDCFH), in addition, the reducing potential was also analysed (RPDPPH). Seasonal differences were detected in all the parameters investigated. The amount of DNA damage detected with the Comet assay and ROS formation highlights the presence of oxidative damage both in winter and in summer samples, while DNA damage (micronucleus) and genes regulation were mainly detected in winter samples. A positive correlation with OPDCFH (Spearman's analysis, p < 0.05) was detected for IL-8 secretion and γ-H2AX. These results provide a biological support to the implementation in air quality monitoring of OP measurements as a useful proxy to estimate PM-induced cellular toxicological responses. In addition, these results provide new insights for the assessment of the ability of secondary aerosol in the background atmosphere to induce oxidative stress and health effects.

The effect of exposure to radiofrequency LTE signal and coexposure to mitomycin-C in Chinese hamster lung fibroblast V79 cells

This study aims to investigate the cellular effects of radiofrequency exposure, 1950 MHz, long-term evolution (LTE) signal, administered alone and in combination with mitomycin-C (MMC), a well-known cytotoxic agent. Chinese hamster lung fibroblast (V79) cells were exposed/sham exposed in a waveguide-based system under strictly controlled conditions of both electromagnetic and environmental parameters, at specific absorption rate (SAR) of 0.3 and 1.25 W/kg. Chromosomal damage (micronuclei formation), oxidative stress (reactive oxygen species [ROS] formation), and cell cycle progression were analyzed after exposure and coexposure. No differences between exposed samples and sham-controls were detected following radiofrequency exposure alone, for all the experimental conditions tested and biological endpoints investigated. When radiofrequency exposure was followed by MMC treatment, 3 h pre-exposure did not modify MMC-induced micronuclei. Pre-exposure of 20 h at 0.3 W/kg did not modify the number of micronuclei induced by MMC, while 1.25 W/kg resulted in a significant reduction of MMC-induced damage. Absence of effects was also detected when CW was used, at both SAR levels. MMC-induced ROS formation resulted significantly decreased at both SAR levels investigated, while cell proliferation and cell cycle progression were not affected by coexposures. The results here reported provide no evidence of direct effects of 1950 MHz, LTE signal. Moreover, they further support our previous findings on the capability of radiofrequency pre-exposure to induce protection from a subsequent toxic treatment, and the key role of the modulated signals and the experimental conditions adopted in eliciting the effect.

Nanoparticles-mediated entomotoxicology: lessons from biologica

Nanotechnology has grown in importance in medicine, manufacturing, and consumer products. Nanoparticles (NPs) are also widely used in the field of insect pest management, where they show a variety of toxicological effects on insects. As a result, the primary goal of this review is to compile and evaluate available information on effects of NPs on insects, by use of a timely, bibliometric analysis. We also discussed the manufacturing capacity of NPs from insect tissues and the toxic effects of NPs on insects. To do so, we searched the Web of Science database for literature from 1995 to 2023 and ran bibliometric analyses with CiteSpace© and Bibliometrix©. The analyses covered 614 journals and identified 1763 relevant documents. We found that accumulation of NPs was one of the top trending topics. China, India, and USA had the most published papers. The most overall reported models of insects were those of Aedes aegypti (yellow fever mosquito), Culex quinquefasciatus (southern house mosquito), Bombyx mori (silk moth), and Anopheles stephensi (Asian malaria mosquito). The application and methods of fabrication of NPs using insect tissues, as well as the mechanism of toxicity of NPs on insects, were also reported. A uniform legal framework is required to allow nanotechnology to fully realize its potential while minimizing harm to living organisms and reducing the release of toxic metalloid nanoparticles into the environment.

Effect of maternal diet on the frequency of micronuclei in pregnant women and newborns: A protocol for systematic review and meta-analysis

BACKGROUND

The effects of diet on maternal and child genetic levels have been previously reported. Diet-associated DNA damage, such as the presence of micronuclei (MN), may be related to an increased risk of developing chronic diseases, such as cancer. Such damage is particularly concerning during pregnancy as it can affect the newborn.

AIM

This review will aim to summarize the primary evidence of the impact of diet during pregnancy on micronucleus frequency in the maternal-newborn population.

METHODS

This protocol was developed based on the Preferred Reporting Items guidelines for Systematic Reviews and Meta-analyses Protocol. The review was registered with the International Register of Prospective Systematic Reviews on February 17, 2022 (registration number: CRD42022302401). We will use PubMed, Embase, Web of Science, Scopus, Science direct, and Google databases to search for observational studies. This review will include studies that investigate the diet consumed by pregnant women and its effect on the frequency of MN in mothers and newborns without any time or language limitations. For data extraction, researchers will independently review the full text and collect information that characterizes the study and its findings. We will analyze the results by calculating the odds ratio for each type of diet evaluated, accompanied by a 95% confidence interval. We will perform a quantitative synthesis of homogeneous studies to perform a meta-analysis. Micronucleus frequency quantifies the effect and will be presented as the mean and standard deviation or median and interquartile range.

EXPECTED RESULTS

This review will aim to identify which dietary patterns during pregnancy may be associated with an increase in the frequency of MN in mothers and their newborns. Understanding the impact of diet on the frequency of MN is essential to deepen studies and to propose strategies that aim to protect the health of the public through food.

Toxicity and underlying lipidomic alterations generated by a mixture of water disinfection byproducts in human lung cells

Complex mixtures of disinfection by-products (DBPs) are present in disinfected waters, but their mixture toxicity has been rarely described. Apart from ingestion, DBP exposure can occur through inhalation, which may lead to respiratory effects in highly exposed individuals. However, the underlying biological mechanisms have yet to be elucidated. This study aimed to investigate the toxicity of a mixture of 10 DBPs, including haloacetic acids and haloaromatics, on human alveolar A549 cells by assessing their cytotoxicity, genotoxicity, and impact on the cell lipidome. A DBP mixture up to 50 μM slightly reduced cell viability, induced the generation of reactive oxygen species (ROS) up to 3.5-fold, and increased the frequency of micronuclei formation. Exposure to 50 μM DBP mixture led to a significant accumulation of triacylglycerides and a decrease of diacylglycerides and phosphatidylcholines in A549 cells. Lipidomic profiling of extracellular vesicles (EVs) released in the culture medium revealed a marked increase in cholesterol esters, sphingomyelins, and other membrane lipids. Overall, these alterations in the lipidome of cells and EVs may indicate a disruption of lipid homeostasis, and thus, potentially contribute to the respiratory effects associated with DBP exposure.

Marketable 1,3-dimethylamylamine and caffeine-based thermogenic supplements: Regulatory genotoxicity assessment through in vitro and in silico approaches

The consumption of dietary supplements to enhance physical performance has increased significantly in the last century, especially thermogenic pre-workout supplements. Nevertheless, this industry has faced criticism for inadequate safety measures surveillance in regulatory issues regarding their products. The aims of our study were to investigate two pre-workout supplements with respect to (1) mutagenicity utilizing Salmonella/microsome assay; (2) genotoxicity employing cytokinesis-block micronucleus (CBMN) assay protocols; and (3) hepatocytoxicity using WST cell proliferation, activities of lactate dehydrogenase (LDH) and alkaline phosphatase using human liver carcinoma (HepG2) and mouse fibroblast (F C3H) cells. Oxidative stress was determined through glutathione (GSH) measurement and in silico for predictions of pharmacokinetics and toxicity for the most abundant isolated substances present in these supplements. Both supplements induced mutagenicity in all examined bacterial strains, especially in the presence of exogenous metabolism. Further, tested supplements significantly elevated the formation of micronuclei (MN) as well as other cellular phenomena. Concentration- and time-dependent curves were observed for hepatotoxicity in both studied cell lines. In addition, both supplements decreased levels of intracellular and extracellular GSH. In silico predictions showed that the isolated individual compounds failed to induce the observed outcomes. Our findings provide contributions to the molecular mechanisms underlying two pre-workout supplement-induced toxicity and the need for surveillance.

Prednisone and prednisolone effects on development, blood, biochemical and histopathological markers of Aquarana catesbeianus tadpoles

Synthetic glucocorticoids are often found in surface waters and can cause harmful effects to aquatic organisms such as amphibians. In this work we evaluated the effects of the drugs prednisone (PD) and prednisolone (PL) on developmental, molecular, blood, biochemical and histological markers. Aquarana catesbeianus tadpoles were exposed for 16 days to environmentally relevant concentrations of 0, 0.1, 1 and 10 µg/L of both drugs. PD increased the transcript levels of the enzyme deiodinase III (Dio3), the hormones cortisol and T4 and delayed development. Changes in the thyroid gland occurred after tadpoles were exposed to both drugs, with a reduction in the diameter and number of follicles and an increase/or decrease in area. Also, both drugs caused a decrease in lymphocytes (L) and an increase in neutrophils (N), thrombocytes, the N:L ratio and lobed and notched erythrocytes. Increased activity of the enzymes superoxide dismutase, glutathione S-transferase and glucose 6-phosphate dehydrogenase was observed after exposure to PD. Furthermore, both drugs caused an increase in the activity of the enzymes catalase and glutathione peroxidase. However, only PD caused oxidative stress in exposed tadpoles, evidenced by increased levels of malondialdehyde and carbonyl proteins. Both drugs caused an increase in inflammatory infiltrates, blood cells and melanomacrophages in the liver. Our results indicate that PD was more toxic than PL, affecting development and causing oxidative stress.

High toxicity of agro-industrial wastewater on aquatic fauna of a South American stream: Mortality of aquatic turtles and amphibian tadpoles as bioindicators of environmental health

The aim of this study was to characterize an aquatic system of Santa Fe province (Argentina) receiving wastewater from agro-industrial activities (mainly dairy) by in situ assessment (fauna mortality, physicochemical, microbiological, and pesticide residues measurement), and ecotoxicity bioassays on amphibian tadpoles. Water and sediment samples were obtained from the Los Troncos Stream (LTS), previous to the confluence with the "San Carlos" drainage channel (SCC), and from the SCC. Biological parameters (mortality and sublethal biomarkers) were used to evaluate ecotoxicity during 10-day exposure of Rhinella arenarum tadpoles to LTS and SCC samples. Nine pesticides were detected in both LTS and SCC. Chemical and biochemical oxygen demand, ammonia, and coliform count recorded in SCC greatly exceeded limits for aquatic life protection. At SCC and LTS after the confluence with SCC, numerous dying and dead aquatic turtles (Phrynops hilarii) were recorded. In the ecotoxicity assessment, no mortality of tadpoles was observed in LTS treatment, whereas total mortality (100%) was observed in SCC treatments in dilution higher than 50% of water and sediment. For SCC, median lethal concentration and the 95% confidence limits was 18.30% (14.71-22.77) at 24 h; lowest-observed and no-observed effect concentrations were 12.5% and 6.25%, respectively. Oxidative stress and neurotoxicity were observed in tadpoles exposed to 25% SCC dilution treatment. In addition, there was a large genotoxic effect (micronuclei test) in all sublethal SCC dilution treatments (6.25%, 12.5%, and 25%). These results alert about the high environmental quality deterioration and high ecotoxicity for aquatic fauna of aquatic ecosystems affected by agro-industrial wastewater. PRACTITIONER POINTS: Great mortality of turtles was observed in a basin with a high load of agro-industrial wastewater. San Carlos Channel (SCC), where effluents are spilled, is environmentally deteriorated. The water-sediment matrix of SCC caused 100% lethality in tadpoles. SCC dilutions caused neurotoxicity, oxidative stress, and genotoxicity on tadpoles.

Artemisia vulgaris L., Artemisia alba Turra and their constituents reduce mitomycin C-induced genomic instability in human peripheral blood lymphocytes in vitro

This study aimed to evaluate the effect of aqueous and acetone extracts from Artemisia vulgaris L. (AV) and Artemisia alba Turra (AA), and two major polyphenols compounds (3,5-dihydroxybenzoic acid and quercetin-3-O-glucopyranoside) presented in both extracts of the plants against mitomycin C (MMC)-induced genomic instability. Genomic instability was measured using cytokinesis block micronucleus (MN) assay in human peripheral blood lymphocytes (PBLs) in vitro by analyzing two biomarkers - MN and nuclear division index (NDI). Extracts were tested in a concentration-dependent manner (10-250 µg/mL), while 3,5-dihydroxybenzoic acid and quercetin-3-O-glucopyranoside were tested in three different concentrations, in combination with 0.5 µg/mL of MMC. Aqueous and acetone extracts obtained from both plants significantly reduced MMC-induced MN frequency in PBLs, compared to positive control cells (p < 0.05). Extracts from AV did not affect NDI, whereas the concentrations of 10-100 μg/mL of aqueous and acetone AA extracts significantly elevated MMC-decreased NDI values in comparison to positive control cells (p < 0.05). Combined treatment of 3,5-dihydroxybenzoic acid and MMC showed a significant reduction of MMC-induced MN frequency, while quercetin-3-O-glucopyranoside increased MN frequency compared to positive control cells (p < 0.05). Both compounds decreased NDI values but only at the highest tested concentration of quercetin-3-O-glucopyranoside it was of greater significance. In conclusion, all extracts from AV and AA and 3,5-dihydroxybenzoic acid showed protective effect, whereby aqueous AA demonstrated the highest protective effect on MMC- induced genomic instability, while quercetin-3-O-glucopyranoside showed co-mutagen effect.

Impacts of horticultural environments on Rhinella arenarum (Anura, Bufonidae) populations: exploring genocytotoxic damage and demographic life history traits

Horticulture poses a significant ecological risk, as agrochemicals are applied more frequently and in larger quantities per unit of production compared to extensive crop fields. The native amphibian Rhinella arenarum serves as a reliable bioindicator of environmental health. This study aimed to assess genocytotoxic damage and demographic life history traits of R. arenarum inhabiting horticultural environments. Sampling was conducted in suburban sites in central Argentina: H1 and H2 (sites associated with horticultural activity) and a reference site, RS. Environmental parameters were recorded, and the frequency of micronuclei (Mn), nuclear abnormalities (ENA), and indicators of cytotoxic damage were determined in tadpoles and adults. Demographic variables (age at maturity, longevity, potential reproductive lifespan, size at maturity, modal lifespan) were calculated. The highest nitrate and phosphate values, along with low dissolved oxygen values, were recorded at sites H1 and H2. Organisms inhabiting horticultural environments exhibited higher frequencies of Mn and ENA, surpassing those recorded in previous studies on tadpoles from sites with extensive crop production. Size at maturity and age at maturity of females, as well as size at maturity, longevity, mean age, and mean adult SVL of males, were lower in horticultural sites. The results support the hypothesis that anuran populations inhabiting horticultural environments demonstrate a diminished health status attributed to subpar environmental quality. Monitoring endpoints at different biological levels provides information on the ecotoxicological risk for amphibians and human populations inhabiting nearby areas.

Nano fraction of pesticide induces genotoxicity and oxidative stress-dependent reticulum stress

The implementation of nanotechnology in different sectors has generated expectations as a new source of use due to the novel characteristics that it will bring. Particularly, nano pesticides promise to be more sustainable and less harmful to the ecosystem and human health; however, most studies continue to focus on their efficacy in the field, leaving aside the effect on humans. This project aimed to evaluate the genotoxic effect of a nano-encapsulated pesticide on bronchial epithelial cells (NL-20) in vitro and elucidate the mechanism through which they induce damage. The nano fraction (NF) of the pesticide Karate Zeon® 5 CS was characterized and isolated, and the uptake into the cell and the changes induced in the cellular ultrastructure were evaluated. In addition, the primary markers of oxidative stress, reticulum stress, and genotoxicity were assessed using the micronucleus test. A 700 nm fraction with a Z potential of -40 mV was obtained, whose main component is polyurea formaldehyde; this allows the capsules to enter the cell through macropinocytosis and clathrin-mediated endocytosis. Inside, they induce oxidative stress activating a reticulum stress response via the BIP protein and the IRE-1 sensor, triggering an inflammatory response. Likewise, stress reduces cell proliferation, increasing genotoxic damage through micronuclei; however, this damage is mainly induced by direct contact of the capsules with the nucleus. This pioneering study uses a nanometric encapsulated commercial pesticide to evaluate the molecular mechanism of induced damage. It makes it the first step in analyzing whether these substances represent a contaminant or an emerging solution.

FEN1 Inhibition as a Potential Novel Targeted Therapy against Breast Cancer and the Prognostic Relevance of FEN1

To improve breast cancer treatment and to enable new strategies for therapeutic resistance, therapeutic targets are constantly being studied. Potential targets are proteins of DNA repair and replication and genomic integrity, such as Flap Endonuclease 1 (FEN1). This study investigated the effects of FEN1 inhibitor FEN1-IN-4 in combination with ionizing radiation on cell death, clonogenic survival, the cell cycle, senescence, doubling time, DNA double-strand breaks and micronuclei in breast cancer cells, breast cells and healthy skin fibroblasts. Furthermore, the variation in the baseline FEN1 level and its influence on treatment prognosis was investigated. The cell lines show specific response patterns in the aspects studied and have heterogeneous baseline FEN1 levels. FEN1-IN-4 has cytotoxic, cytostatic and radiosensitizing effects, expressed through increasing cell death by apoptosis and necrosis, G2M share, senescence, double-strand breaks and a reduced survival fraction. Nevertheless, some cells are less affected by the cytotoxicity and fibroblasts show a rather limited response. In vivo, high FEN1 mRNA expression worsens the prognosis of breast cancer patients. Due to the increased expression in breast cancer tissue, FEN1 could represent a new tumor and prognosis marker and FEN1-IN-4 may serve as a new potent agent in personalized medicine and targeted breast cancer therapy.

Non-regulated haloaromatic water disinfection byproducts act as endocrine and lipid disrupters in human placental cells

The disinfection of drinking water generates hundreds of disinfection byproducts (DBPs), including haloaromatic DBPs. These haloaromatic DBPs are suspected to be more toxic than haloaliphatic ones, and they are currently not regulated. This work investigates their toxicity and ability to interfere with estrogen synthesis in human placental JEG-3 cells, and their genotoxic potential in human alveolar A549 cells. Among the haloaromatic DBPs studied, halobenzoquinones (2,6-dichloro-1,4-benzoquinone (DCBQ) and 2,6-dibromo-1,4-benzoquinone (DBBQ)) showed the highest cytotoxicity (EC50: 18-26 μg/mL). They induced the generation of very high levels of reactive oxygen species (ROS) and up-regulated the expression of genes involved in estrogen synthesis (cyp19a1, hsd17b1). Increased ROS was linked to significant depletion of polyunsaturated lipid species from inner cell membranes. The other DBPs tested showed low or no significant cytotoxicity (EC50 ≥ 100 μg/mL), while 2,4,6-trichloro-phenol (TCP), 2,4,6-tribromo-phenol (TBP) and 3,5-dibromo-4-hydroxybenzaldehyde (DCHB) induced the formation of micronuclei at concentrations much higher than those typically found in water (100 μg/mL). This study reveals the different modes of action of haloaromatic DBPs, and highlights the toxic potential of halobenzoquinones, which had a significant impact on the expression of placenta steroid metabolism related genes and induce oxidative stress, implying potential adverse health effects.

Telomere Length, Mitochondrial DNA, and Micronucleus Yield in Response to Oxidative Stress in Peripheral Blood Mononuclear Cells

Telomere shortening, chromosomal damage, and mitochondrial dysfunction are major initiators of cell aging and biomarkers of many diseases. However, the underlying correlations between nuclear and mitochondrial DNA alterations remain unclear. We investigated the relationship between telomere length (TL) and micronucleus (MN) and their association with mitochondrial DNA copy number (mtDNAcn) in peripheral blood mononuclear cells (PBMCs) in response to 100 μM and 200 μM of hydrogen peroxide (H2O2) at 44, 72, and 96 h. Significant TL shortening was observed after both doses of H2O2 and at all times (all p < 0.05). A concomitant increase in MN was found at 72 h (p < 0.01) and persisted at 96 h (p < 0.01). An increase in mtDNAcn (p = 0.04) at 200 µM of H2O2 was also found. In PBMCs treated with 200 µM H2O2, a significant inverse correlation was found between TL and MN (r = -0.76, p = 0.03), and mtDNA content was directly correlated with TL (r = 0.6, p = 0.04) and inversely related to MN (r = -0.78, p = 0.02). Telomere shortening is the main triggering mechanism of chromosomal damage in stimulated T lymphocytes under oxidative stress. The significant correlations between nuclear DNA damage and mtDNAcn support the notion of a telomere-mitochondria axis that might influence age-associated pathologies and be a target for the development of relevant anti-aging drugs.

Combinatorial targeting of telomerase and DNA-PK induces synergistic apoptotic effects against Pre-B acute lymphoblastic leukemia cells

BACKGROUND

Due to the high demand for novel approaches for leukemia-targeted therapy, this study investigates the impact of DNA-PK inhibitor NU7441 on the sensitivity of pre-B ALL cells to the telomerase inhibitor MST-312.

METHODS

The study involved NALM-6 cells treated with MST-312 and NU7441, assessing their viability and metabolic activity using trypan blue and MTT assays. The study also evaluated apoptosis, gene expression changes, and DNA damage using flow cytometry, qRT-PCR, and micronucleus assays. The binding energy of MST-312 in the active site of telomerase was calculated using molecular docking.

RESULTS

The study's findings revealed a synergistic decline in both cell viability and metabolic activity in NALM-6 cells when exposed to the combined treatment of MST-312 and NU7441, and this decrease occurred without any adverse effects on healthy PBMC cells. Furthermore, the combination treatment exhibited a significantly higher induction of apoptosis than treatment with MST-312 alone, as observed through flow cytometry assay. qRT-PCR analysis revealed that this enhanced apoptosis was associated with a notable downregulation of Bcl-2 expression and an upregulation of Bax gene expression. Moreover, the combination therapy decreased expression levels of hTERT and c-Myc genes. The micronucleus assay indicated that the combination treatment increased DNA damage in NALM-6 cells. Also, a good conformation between MST-312 and the active site of telomerase was revealed by docking data.

CONCLUSIONS

The study suggests that simultaneous inhibition of telomerase and DNA-PK in pre-B ALL presents a novel targeted therapy approach.

Evaluation of the genotoxicity, cytotoxicity, and bioactivity of calcium silicate-based cements

BACKGROUND

As calcium silicate-based cements (CSCs) have found success in various vital pulp therapy applications, several new CSC products have emerged. This study aimed to assess the genotoxicity, cytotoxicity, and bioactivity of four CSCs by comparing the newly introduced materials Bio MTA+ and MTA Cem with previously studied materials, Biodentine and NeoMTA.

METHODS

Genotoxicity was evaluated using the micronucleus (MN) assay in human peripheral blood lymphocyte cells, measuring MN frequency and nuclear division index (NDI). Cytotoxicity was assessed in human dental pulp stem cells through the Water-Soluble Tetrazolium Salt-1 (WST-1) colorimetric assay. Bioactivity was determined by ELISA, measuring the levels of angiogenic and odontogenic markers (BMP-2, FGF-2, VEGF, and ALP). Statistical analyses included ANOVA, Dunnet and Sidak tests, and Wald chi-square test. (p < .05).

RESULTS

The MN frequency in the groups was significantly lower than that in the positive control group (tetraconazole) (p < .05). NDI values decreased with increasing concentration (p < .05). Bio MTA+ and NeoMTA showed decreased cell viability at all concentrations in 7-day cultures (p < .01). All materials increased BMP-2, FGF-2, and VEGF levels, with Biodentine and NeoMTA showing the highest levels of BMP-2 and FGF-2 on day 7. Biodentine displayed the highest VEGF levels on day 7. Biodentine and NeoMTA groups exhibited significantly higher ALP activity than the Bio MTA+ and MTA Cem groups by day 7.

CONCLUSION

Bio MTA+ and MTA Cem demonstrated no genotoxic or cytotoxic effects. Moreover, this study revealed bioactive potentials of Bio MTA+ and MTA Cem by enhancing the expression of angiogenic and osteogenic growth factors.

Guidance for the use and interpretation of assays for monitoring anti-genotoxicity

Since DNA damage can occur spontaneously or be produced by the environmental genotoxins in living cells, it is important to investigate compounds that can reverse or protect DNA damage. An appropriate methodology is essential for the responsive identification of protection offered against DNA damage. This review includes information on the current state of knowledge on prokaryotic cell-based assays (SOS chromotest, umu test, vitotox assay) and cytogenetic techniques (micronucleus assay, chromosome aberration test and sister chromatid exchange assay) with an emphasis on the possibility to explore genoprotective compounds. Throughout the last decade, studies have extrapolated the scientific methodologies utilized for genotoxicity to assess genoprotective compounds. Therefore, shortcomings of genotoxicity studies are also mirrored in antigenotoxicity studies. While regulatory authorities around the world (OECD, US-EPA and ICH) continue to update diverse genotoxic assay strategies, there are still no clear guidelines/approaches for efficient experimental design to screen genoprotective compounds. As a consequence, non-synergetic and inconsistent implementation of the test method by the researchers to execute such simulations has been adopted, which inevitably results in unreliable findings. The review has made the first attempt to collect various facets of experimentally verified approaches for evaluating genoprotective compounds, as well as to acknowledge potential significance and constraints, and further focus on the assessment of end points which are required to validate such action. Henceforth, the review makes an incredible commitment by permitting readers to equate several components of their test arrangement with the provided simplified information, allowing the selection of convenient technique for the predefined compound from a central repository.

Study of the DNA damage and cell death in human peripheral blood mononuclear and HepG2/C3A cells exposed to the synthetic 3-(3-hydroxyphenyl)-7-hydroxycoumarin

Hydroxycoumarins are an important source of biologically active compounds. Previous studies have shown that the number and position of the hydroxyl substituents in the scaffold play an important role for the observed biological activity. In the present study, 3-(3-hydroxyphenyl)-7-hydroxycoumarin was synthesized, and potential cytogenotoxic effects determined in human HepG2/C3A cells displaying phase 1 and phase 2 enzymes (metabolizing cell ability) and compared to human peripheral blood mononuclear cells (PBMC) without xenobiotics metabolizing capacity. Cell viability was determined with concentrations between 0.01 and 10 µg/ml of 3-(3-hydroxyphenyl)-7-hydroxycoumarin using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) and trypan blue tests. Genotoxicity was determined utilizing the comet assay, and the clastogenic/aneugenic potential employing the micronucleus (MN) test. The results of the in vitro cytotoxicity assays showed a significant decrease in cell viability of PBMC following exposure to 10 µg/ml concentration of the studied compound after 48 and 72 hr. Comet assay observations noted significant DNA damage in PBMC after 4 hr treatment. No marked cytogenotoxic effects were found in HepG2/C3A cells. No chromosomal mutations were observed in both cell lines. It is important to note that 3-(3-hydroxyphenyl)-7-hydroxycoumarin may exert beneficial pharmacological actions at the low micromolar range and with half-life less than 24 hr. Therefore, the results obtained encourage the continuation of studies on this new molecule for medicinal purposes, but its potential toxicity at higher concentrations and longer exposure times needs to be investigated in further studies.

Occupational exposure to radiation among health workers: Genome integrity and predictors of exposure

The current study aimed to investigate genomic instabilities in healthcare workers who may experience varying levels of radiation exposure through various radiological procedures. It also sought to determine if factors related to the work environment and dosimeter reading could effectively explain the observed genomic instabilities. Utilizing the cytokinesis-block micronucleus assay (CBMN) on peripheral blood lymphocytes, we assessed a spectrum of genomic aberrations, including nucleoplasmic bridge (NPB), nuclear budding (NBUD), micronucleus (MN) formation, and total DNA damage (TDD). The study uncovered a statistically significant increase in the occurrence of distinct DNA anomalies among radiology workers (with a significance level of P < 0.0001 for all measurements). Notably, parameters such as total working hours, average work duration, and time spent in projection radiography exhibited significant correlations with MN and TDD levels in these workers. The dosimeter readings demonstrated a positive correlation with the frequency of NPB and NBUD, indicating a substantial association between radiation exposure and these two genomic anomalies. Our multivariable models identified the time spent in projection radiography as a promising parameter for explaining the overall genomic instability observed in these professionals. Thus, while dosimeters alone may not fully explain elevated total DNA damage, intrinsic work environment factors hold potential in indicating exposure levels for these individuals, providing a complementary approach to monitoring.

Breast cancer cells are sensitized by piperine to radiotherapy through estrogen receptor-α mediated modulation of a key NHEJ repair protein- DNA-PK

BACKGROUND

Non-homologous end joining, an important DNA-double-stranded break repair pathway, plays a prominent role in conferring resistance to radiotherapeutic agents, resulting in cancer progression and relapse.

PURPOSE

The molecular players involved in the radio-sensitizing effects of piperine and many other phytocompounds remain evasive to a great extent. The study is designed to assess if piperine, a plant alkaloid can alter the radioresistance by modulating the expression of non-homologous end-joining machinery.

METHODS AND MATERIALS

Estrogen receptor-positive/negative, breast cancer cells were cultured to understand the synergetic effects of piperine with radiotherapy. Cisplatin and Bazedoxifene were used as positive controls. Cells were exposed to γ- radiation using Low Dose gamma Irradiator-2000. The piperine effect on Estrogen receptor modulation, DNA-Damage, DNA-Damage-Response, and apoptosis was done by western blotting, immunofluorescence, yeast-based-estrogen-receptor-LacZ-reporter assay, and nuclear translocation analysis. Micronuclei assay was done for DNA damage and genotoxicity, and DSBs were quantified by γH2AX-foci-staining using confocal microscopy. Flow cytometry analysis was done to determine the cell cycle, mitochondrial membrane depolarization, and Reactive oxygen species generation. Pharmacophore analysis and protein-ligand interaction studies were done using Schrodinger software. Synergy was computed by compusyn-statistical analysis. Standard errors/deviation/significance were computed with GraphPad prism.

RESULTS

Using piperine, we propose a new strategy for overcoming acquired radioresistance through estrogen receptor-mediated modulation of the NHEJ pathway. This is the first comprehensive study elucidating the mechanism of radio sensitizing potential of piperine. Piperine enhanced the radiation-induced cell death and enhanced the expression and activation of Estrogen receptor β, while Estrogen receptor α expression and activation were reduced. In addition, piperine shares common pharmacophore features with most of the known estrogen agonists and antagonists. It altered the estrogen receptor α/β ratio and the expression of estrogen-responsive proteins of DDR and NHEJ pathway. Enhanced expression of DDR proteins, ATM, p53, and P-p53 with low DNA-PK repair complex (comprising of DNA-PKcs/Ku70/Ku80), resulted in the accumulation of radiation-induced DNA double-stranded breaks (as evidenced by MNi and γH2AX-foci) culminating in cell cycle arrest and mitochondrial-pathway of apoptosis.

CONCLUSION

In conclusion, our study for the first time reported that piperine sensitizes breast cancer cells to radiation by accumulating DNA breaks, through altering the expression of DNA-PK Complex, and DDR proteins, via selective estrogen receptor modulation, offering a novel strategy for combating radioresistance.

DNA damage in workers exposed to pigment grade titanium dioxide (TiO2) and association with biomarkers of oxidative stress and inflammation

The present study was aimed at investigating DNA damage, micronuclei frequency and meta-nuclear alterations in buccal cells of workers involved in pigment-grade TiO2 production (15 exposed and 20 not-exposed). We also assessed associations of genotoxicity biomarkers with oxidative stress/inflammatory biomarkers in urine and exhaled breath condensate (EBC), as well as possible associations between biomarkers and reported respiratory symptoms. In spite of compliance with TiO2 Occupational Exposure Limits, results showed increased direct/oxidative DNA damage and micronuclei frequency in exposed workers. Genotoxicity parameters were associated with oxidative stress/inflammation biomarkers in urine and EBC, thus confirming that TiO2 exposure can affect the oxidative balance. Workers with higher genotoxic/oxidative stress biomarkers levels reported early respiratory symptoms suggesting that molecular alterations can be predictive of early health dysfunctions. These findings suggest the need to assess early health impairment in health surveillance programs and to address properly safety issues in workplaces where TiO2 is handled.

Effect on growth and development of common toad (Rhinella arenarum) tadpoles in environment related to fluorite mine

Fluorite mining activities have been scarcely evaluated so far and the potential effect of this activity on larval stages is poorly known. Thus, studies addressing the effect of contaminants present in water bodies on the health of amphibian larvae are crucial information for their conservation and constitute a warning sign of environmental modification. This study aims to evaluate the effects of natural and artificial surface waters associated with a fluorite mine on the early life stages of Rhinella arenarum. Using microcosms, we assessed four sites with different degrees of disturbance by the fluorine mine: Vallecitos stream (undisturbed); Cerros Negros upstream of mining camp (low disturbance); Cerros Negro downstream of mining camp (medium disturbance); Decantation Ponds (high disturbance). For 65 days we measured different endpoints at different periods of tadpole development. The highest mortality of tadpoles was observed in the Decantation Ponds. In the same way, larval body condition was lower at Decantation Ponds throughout the study, due mainly to the lower weight. A significant decrease in growth and development was observed in Cerros Negro downstream of the mining camp and Decantation Ponds. No significant differences in growth, development and mortality were observed for the other two sites. At the metamorphic climax we observe a lower body condition and a reduced recruitment of individuals in Decantation Ponds. This study allowed us to assess the effect on larvae of R. arenarum of fluorite mining wastewater compared with other near-natural sites. Given the potentially negative synergic effects of mixed water pollutants on tadpoles, this study suggests that chronic exposure to fluorite mining water may significantly impact the adult amphibian population structure, thus altering population viability. Therefore, we propose to monitor the correct functioning of the mine and especially of Decantation Ponds to avoid discharges into the natural streams.

Determination of the genotoxic effects of sweeteners, mannitol and lactitol

The changes in dietary habit around the world have led to an increased use of additives in the food. The safety of food additives has been a main focus of research for many years due to the ongoing debate on their potential effects on health. In this study, the in vitro genotoxic effects of mannitol and lactitol, polyols used as sweetener food additives, were evaluated using chromosomal aberrations (CAs) and micronucleus (MN) assays in human peripheral lymphocytes. Additionally, the effects of these sweeteners on the mitotic index (MI) and nuclear division index (NDI) were investigated. Concentrations of 500, 1000, 2000, 4000, and 8000 μg/mL for mannitol and 250, 500, 1000, 2000, and 4000 μg/mL for lactitol were used. The results indicated that both polyols did not affect CA and MN frequency, and did not cause a significant change in NDI at all treatment concentratoins. However, mannitol (except at concentrations of 500 and 1000 μg/mL) and lactitol (except at 250 μg/mL) significantly decreased the MI compared to the control at almost all concentrations and treatment times. In conclusion, it was observed that mannitol and lactitol did not have a significant genotoxic effect at the concentrations used in human lymphocytes in vitro.

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.

Response of Fibroblasts from Menkes' and Wilson's Copper Metabolism-Related Disorders to Ionizing Radiation: Influence of the Nucleo-Shuttling of the ATM Protein Kinase

Menkes' disease (MD) and Wilson's disease (WD) are two major copper (Cu) metabolism-related disorders caused by mutations of the ATP7A and ATP7B ATPase gene, respectively. While Cu is involved in DNA strand breaks signaling and repair, the response of cells from both diseases to ionizing radiation, a common DNA strand breaks inducer, has not been investigated yet. To this aim, three MD and two WD skin fibroblasts lines were irradiated at two Gy X-rays and clonogenic cell survival, micronuclei, anti-γH2AX, -pATM, and -MRE11 immunofluorescence assays were applied to evaluate the DNA double-strand breaks (DSB) recognition and repair. MD and WD cells appeared moderately radiosensitive with a delay in the radiation-induced ATM nucleo-shuttling (RIANS) associated with impairments in the DSB recognition. Such delayed RIANS was notably caused in both MD and WD cells by a highly expressed ATP7B protein that forms complexes with ATM monomers in cytoplasm. Interestingly, a Cu pre-treatment of cells may influence the activity of the MRE11 nuclease and modulate the radiobiological phenotype. Lastly, some high-passage MD cells cultured in routine may transform spontaneously becoming immortalized. Altogether, our findings suggest that exposure to ionizing radiation may impact on clinical features of MD and WD, which requires cautiousness when affected patients are submitted to radiodiagnosis and, eventually, radiotherapy.

High-LET charged particles: radiobiology and application for new approaches in radiotherapy

The number of patients treated with charged-particle radiotherapy as well as the number of treatment centers is increasing worldwide, particularly regarding protons. However, high-linear energy transfer (LET) particles, mainly carbon ions, are of special interest for application in radiotherapy, as their special physical features result in high precision and hence lower toxicity, and at the same time in increased efficiency in cell inactivation in the target region, i.e., the tumor. The radiobiology of high-LET particles differs with respect to DNA damage repair, cytogenetic damage, and cell death type, and their increased LET can tackle cells' resistance to hypoxia. Recent developments and perspectives, e.g., the return of high-LET particle therapy to the US with a center planned at Mayo clinics, the application of carbon ion radiotherapy using cost-reducing cyclotrons and the application of helium is foreseen to increase the interest in this type of radiotherapy. However, further preclinical research is needed to better understand the differential radiobiological mechanisms as opposed to photon radiotherapy, which will help to guide future clinical studies for optimal exploitation of high-LET particle therapy, in particular related to new concepts and innovative approaches. Herein, we summarize the basics and recent progress in high-LET particle radiobiology with a focus on carbon ions and discuss the implications of current knowledge for charged-particle radiotherapy. We emphasize the potential of high-LET particles with respect to immunogenicity and especially their combination with immunotherapy.