Smoking is a cause of serious diseases in adult smokers. Next generation products (NGP) can provide potentially reduced harm alternatives of nicotine delivery, due to the reductions in numbers and levels of toxicants associated with their use. These include heated tobacco and herbal products (HTPs/ HHPs) and electronic vapour products (EVPs). This study assessed the effects of a range of NGP (an HTP, an HHP and two EVPs) and a reference cigarette (1R6F) in the ToxTracker Antioxidant (AO) and ToxProfiler Mitotox Assessment Xtension (MAX) assays, which provide mechanistic insights via a range of cell stress endpoints. Aqueous extracts of smoke/ aerosol were generated by bubbling through phosphate-buffered saline solution, which was analysed for nicotine and carbonyl content. In the ToxTracker AO assay, 1R6F induced oxidative stress, genotoxicity and protein damage responses. Addition of N-acetyl cysteine (NAC) and glutathione (GSH) partially reduced selected responses, indicating oxidative stress contributes but does not fully account for all observed effects. Oxidative stress responses followed a similar trend for HTP; but was not classed as genotoxic. The HHP induced one oxidative stress marker, which was reduced by the addition of NAC/GSH. In the ToxProfiler MAX assay, 1R6F induced oxidative, endoplasmic reticulum and cell cycle stress. HTP induced the same stress pathways but was less potent than 1R6F. The HHP only induced an oxidative stress response, and at higher concentrations than 1R6F. The EVPs did not induce any of the cell stress markers across both assays and none of the test products induced mitochondrial toxicity. Overall, biological activity followed a decreasing gradient from 1R6F to HTP, HHP and EVPs. The findings of the assays used in this study reflect the proposed placement of such products on the relative reduced risk scale based on their smoke/aerosol chemistry and thus highlights the tobacco harm reduction potential of NGP.

The comet assay is a widely used tool for evaluating DNA damage in various biological samples, with frozen whole blood (WB) as an attractive biomatrix, due to its ease of collection, handling, and storage. Although frozen WB has been successfully applied in the comet assay to study DNA damage, its application in the comet assay to study potential protective mechanisms, such as DNA repair or antioxidant capacity, has not been fully established yet. In this study, we set up a protocol using frozen WB for assessing base excision repair (BER) activity and further optimized the protocol to assess the cellular antioxidant defense capacity against oxidation-induced DNA damage. White blood cells (WBCs) were isolated to extract proteins, and a protein concentration of 2 mg/mL enabled reliable detection of BER activity, even in samples stored for up to 27 months. This optimized assay was subsequently applied in a pilot study involving 28 participants with either a family tumor history (FTH, n = 10) or not (NFTH, n = 18). The FTH group exhibited significantly less BER activity compared to the NFTH group (p = 0.005). In addition, the hydrogen peroxide (H2O2) challenge comet assay was further optimized to assess the cellular antioxidant defense capacity against oxidation-induced DNA damage in frozen WB and subsequently applied to a cohort study (n = 140). Frequent intake of seeds (p = 0.025) and vegetables (p = 0.003) was observed to protect against H2O2-induced DNA damage. Together, these innovations expand the applications of the comet assay in frozen blood samples, providing a more comprehensive biomonitoring toolbox. By enabling reliable measurements of DNA damage, antioxidant capacity, and DNA repair activity from a single frozen blood sample, these assays are ideally suited for large-scale human biomonitoring and clinical studies.

Inflammatory bowel disease (IBD) is associated with alterations in the intestinal luminal environment that may modify the composition of fecal water (FW) and its capacity to induce DNA damage. The aim of this study was to identify FW metabolites associated with DNA damage and aryl hydrocarbon receptor (AhR) activity and to investigate whether shared metabolic pathways may link these responses in patients with IBD. FW samples from 80 IBD patients and 20 healthy controls were analyzed. DNA damage in Caco-2 cells following FW exposure was assessed using the comet assay, AhR activity using the ethoxyresorufin-O-deethylase (EROD) assay, and FW metabolites by using liquid chromatography-mass spectrometry. Metabolite signatures associated with DNA damage and AhR activity were identified separately, and subsequent pathway analysis revealed overlapping metabolic pathways, prompting further investigation of AhR-associated tryptophan metabolites. Kynurenine was inversely associated with AhR activity but positively associated with DNA damage in IBD, whereas serotonin was positively related to AhR activity and was protective against FW-induced DNA damage. Indoles did not significantly contribute to FW-induced DNA damage. These findings suggest that inflammation-associated alterations in tryptophan metabolism are associated with altered AhR signaling and epithelial DNA damage in IBD.

Human exposure scenarios to emerging pollutants, micro- and nanoplastics are increasing. However, in vivo reports defining their acute genotoxic hazard, particularly under combined (microplastics (MPs) + nanoplastics (NPs)) exposure are limited. Polystyrene (PS) MPs and NPs are among the most prevalent and are being detected in food and environmental matrices. Hence, we investigated the acute genotoxic effects of PS MPs, NPs, and MPs+NPs treatment following oral administration at 10, 100, and 1000 mg/kg body weight doses in female Wistar rats. Particle characterization confirmed polymer integrity and size distribution, with hydrodynamic diameters of 1422 nm for MPs and 112.3 nm for NPs in Milli-Q water. A dose-dependent hepatic and renal injury was observed in histopathological studies and the effect was more prominent at the 1000 mg/kg dose in rats treated with PS MPs+NPs. Comet assay results showed significant DNA damage in peripheral blood leukocytes, bone marrow, liver, and kidney cells with PS NPs and MPs+NPs compared with PS MPs treatment alone. Notably, PS MPs+NPs exposure induced DNA damage even at the lowest dose (10 mg/kg) tested. Cell cycle analysis in rats treated with PS MPs and NPs depicted arrest in G0/G1, S, and G2/M phases which was consistent with activation of DNA damage checkpoints. A dose dependent elevation in Thiobarbituric acid reactive substances (TBARS) levels levels and depletion of reduced glutathione in plasma samples of rats indicate disruption of redox homeostasis. Overall, the findings of this study provide invaluable insights on PS plastic particles in vivo effects after acute oral exposure indicating oxidative stress mediated DNA damage, cell cycle perturbation, and tissue injury. The overall toxicity trend followed the order MPs+NPs > NPs > MPs, suggesting enhanced toxicity following combined exposure and highlighting the need for long-term toxicity studies of MPs+NPs mixtures to inform regulatory risk assessment.

Obesity is defined as the excessive accumulation of fat that can lead to the development of several diseases, such as type 2 diabetes and cardiovascular diseases. Dietary studies using animal models are essential to elucidate the mechanisms involved in obesity development. Diet-induced obesity models, including the cafeteria diet (CAF), have been employed to study obesity in rodents. Currently, research efforts have focused on treatment strategies for the metabolic dysfunctions caused by obesity. Omega-3 (O3) plays a crucial role in body development throughout life; therefore, this study aimed to evaluate the effect of O3 supplementation on biochemical and genotoxic parameters in mice that were fed a cafeteria diet. Forty-eight mice were divided into six groups (n=8/group): Standard Diet (SD); SD with O3 supplementation; CAF; CAF with O3 supplementation; CAF switched to SD; and CAF switched to SD with O3 supplementation. Animals were fed either a cafeteria or standard diet for 16 weeks and monitored for mass changes. O3 supplementation by gavage or diet switch began after the initial 16 weeks and lasted 4 weeks. At week 20, the mass was assessed again, and blood samples were collected for biochemical analyses and insulin tolerance tests. Following euthanasia, genotoxic analyses were performed. The present study demonstrated that the CAF diet led to increased food and energy intake, body mass, adiposity index, fasting blood glucose levels, insulin resistance, and genomic instability in mice. O3 supplementation partially attenuated these effects by reducing food intake, body weight, adiposity index, fasting blood glucose levels and DNA damage. The results of this study suggest that the observed improvements in metabolic and genotoxic parameters are primarily driven by reductions in energy intake and adiposity, with O3 supplementation being associated with reduced food intake under cafeteria diet conditions, highlighting its contribution to the modulation of obesity-related metabolic and genotoxic alterations.

Osteosarcoma is an aggressive malignant bone tumor that often requires chemotherapy with agents such as doxorubicin (Dox), which is known for its potent cytotoxic and genotoxic effects. To manage cancer-related pain, morphine is widely used due to its strong analgesic properties. The concurrent administration of these drugs in clinical practice might affect cancer therapy, since Dox is a well-established inducer of genomic instability, whereas the potential contribution of morphine to this process remains poorly understood. This study evaluated the cytotoxicity, genotoxicity, and chromosomal damage induced by morphine, both alone and in combination with Dox. Cytotoxicity was assessed in MG63 osteosarcoma cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Genotoxicity and chromosomal damage were evaluated in MG63 and non-tumor V79 fibroblast cells using the comet assay and the cytokinesis-block micronucleus (CBMN) assay. Morphine alone induced DNA damage in both MG63 and V79 cells in the comet assay and increased micronucleus frequency only in MG63 cells. In co-treatment, morphine significantly reduced Dox-induced DNA damage and chromosomal instability parameters in the CBMN assay in MG63 cells. Conversely, micronucleus frequency increased in co-treatment in V79 cells. Overall, morphine alone increased chromosomal damage in MG63 tumor cells but not in V79 non-tumor cells. However, in combination with Dox, morphine attenuated Dox-induced genomic instability in osteosarcoma cells while enhancing chromosomal damage in non-tumor fibroblasts. These findings suggest that morphine may differentially modulate the genomic effects of Dox, potentially impacting both antitumor efficacy and genomic stability in normal cells.

The 38th annual meeting of the Industrial Genotoxicology Group (IGG) was held at Lhasa Limited, Leeds, UK on 2 December 2025, and focussed on the assessment of biological relevance in genotoxicity testing and the appropriate use of historical negative control data. Presentations covered updates on assay development, practical challenges in interpreting borderline or equivocal results, and evolving regulatory expectations across OECD and International Council for Harmonisation (ICH) frameworks. The meeting also featured the New Investigator Technical Award and the Lhasa Young Scientist Memorial Award, recognising innovative technical contributions across the field. Through scientific sessions and an interactive workshop, attendees explored case studies illustrating how statistical significance, biological relevance, and quality of historical negative control (HNC) data intersect in regulatory decision-making. Key themes included the stability and interpretation of historical control data ranges, the application of statistical process control, and the complexities of assigning confidence to negative findings. The meeting highlighted the continued need for expert judgement when assessing genotoxic outcomes and the importance of transparent, high-quality data to support regulatory conclusions.

Anthocyanins are flavonoid pigments responsible for red, blue, and purple coloration in plants and play a protective role against abiotic stress through reactive oxygen species scavenging. They are abundant in the human diet, with berries serving as a primary source. These flavonoids are known for their antioxidant and potential geno-protective properties. However, the effect of glycosylation on their biological activity remains incompletely understood. This study investigated the influence of glycosylation on the antioxidant and DNA-protective effects of delphinidin (aglycone), comparing the aglycone with pure glycosylated derivatives and a standardized Maqui berry extract 'PREVAID' rich in delphinidin glycosides. Using human colon adenocarcinoma (Caco-2) cells, oxidative stress was induced with hydrogen peroxide (H2O2) and assessed via 2',7'-dichlorodihydrofluorescein diacetate (DCFH2-DA). Oxidative DNA damage protection was evaluated with the formamidopyrimidine DNA glycosylase (FPG)-modified comet assay, and geno-protection against cytochrome P450-mediated activation of riddelliine was assessed by the micronucleus assay in human hepatoma (HepG2) cells. Both delphinidin and its glycosylated derivatives significantly reduced intracellular ROS and protected against oxidative DNA damage. Protective effects persisted following medium replacement, indicating intracellular uptake and activity. In the micronucleus assay, delphinidin and its glycosides attenuated riddelliine-induced genotoxicity, suggesting interference with cytochrome P450-mediated metabolic activation. These findings demonstrate that glycosylation does not abolish the antioxidant and geno-protective properties of delphinidin. The results have important implications for understanding dietary anthocyanin bioactivity and guiding the development of anthocyanin-based nutraceuticals.

The indoor environment changes based on a variety of different factors, therefore changing the genotoxic potential of that environment. Despite the associations of exposure to outdoor air pollution and links to health impacts, enough is not currently known about the impacts to human health indoor air may have. Due to the variable nature of the indoor environment (multiple things can change this environment, including but not limited to, the use, occupants, materials within the environment, animals, the outside environment and ventilation) this can prove difficult. Indoor particulate matter (PM) of various sizes (PM2.5-PM10 for example) has been shown to induce reactive oxygen species, increase markers in oxidative stress, double strand DNA breaks, and cause 8-oxoguanine lesions in both in vitro and in vivo models (including humans). The particle type and source influence these responses, highlighting heating and cooking fuel sources that may be more genotoxic than others. A similar pattern has also been observed with volatile organic compounds (VOCs) with various mixtures of VOCs and different VOC compositions inducing DNA damage differently, with diet also being a contributing factor to genotoxic potential. A significant knowledge gap in the potential genotoxicity of indoor air pollution is the exposure of various biologicals found indoors. Moulds, other fungi, and allergens are an emerging health risk and are of significant public interest. Little is known about the inhalation toxicology and mechanisms of action of these components, and this is becoming increasing important to understand due to public deaths linked to them. There is overlap with the health effects of outdoor air pollution where there has been much more research focus. Therefore, the aim of this review is to establish what is already known, the potential limitations of the current work and where we should focus research in the future.

Triammonium citrate (TAC) is a citrate salt widely utilized in diverse industrial and dietary applications, leading to widespread human exposure. While related citrate salts have established safety profiles, the specific genotoxic potential and molecular interactions of TAC remain largely unexplored. This study provides the first integrated in vitro and in silico mechanistic safety assessment of TAC. Cell viability, evaluated in NIH/3T3 and MCF-7 cells via the CCK-8 assay, remained above 90% at all tested concentrations (0.25-2 mg/mL). Furthermore, a comprehensive genotoxicity battery-including the Ames test, chromosomal aberration, micronucleus, and sister chromatid exchange assays in human lymphocytes-revealed no mutagenic, clastogenic, or aneugenic activity. Beyond its safety profile, TAC exhibited marked chemoprotective activity, preserving supercoiled plasmid DNA with up to 96% protection against H2O2-induced oxidative damage. Molecular docking studies substantiated these findings by predicting moderate binding affinities for DNA replication enzymes (DNA polymerase δ: ΔG = -5.7 kcal/mol; topoisomerase I: ΔG = -5.9 kcal/mol) while showing a preferential affinity for the metabolic enzyme glutamine synthetase (ΔG = -6.1 kcal/mol). These in silico results suggest that TAC does not interfere with critical DNA maintenance machinery. Collectively, these findings establish a robust safety profile for TAC and unveil a previously unrecognized, antioxidant-mediated DNA-protective function, highlighting its potential as a bioactive functional ingredient capable of mitigating oxidative DNA stress.

Maternal nutrition can influence genetic health during pregnancy, increasing the risk of DNA damage in both the mother and fetus. This study investigated the effect of maternal nutritional factors on DNA damage biomarkers in the mother-infant dyad. A cross-sectional study was conducted with pregnant women residing in Northeast Brazil. Participants included women aged ≥18 years in the third trimester, excluding those with non-communicable chronic diseases and smokers. Data collection included sociodemographic, lifestyle, anthropometric information, and a 76-item Food Frequency Questionnaire. The micronucleus cytome assay was performed on oral mucosa cells, with DNA damage biomarkers expressed per thousand cells (‰). Statistical analysis involved hierarchical clustering and Generalized Linear Models using Jamovi 2.5.6. The median age of the pregnant women (n = 209) was 26 years. Only 44.5% had adequate pre-pregnancy nutritional status, with a 9.5% increase in low birth weight. Total energy intake was 1842 (588-5709) kcal, with 72% consuming less than 90% of their caloric needs. The diet was predominantly hyperproteic and hyperlipidic, with over 60% showing inadequate intake of magnesium and folic acid. Among 209 participants, 80 consented to oral mucosa cell collection, and 59 mother-infant pairs were analyzed. Three maternal nutritional profiles were identified: Cluster 1 ("Multiple Burdens of Malnutrition"), Cluster 2 ("Low Burdens of Malnutrition"), and Cluster 3 ("High Nutritional Intake"). While maternal nutritional profiles did not affect nuclear abnormalities in mothers, they influenced newborns. Infants of mothers in Clusters 1 and 2 exhibited more nuclear abnormalities than those in Cluster 3. Maternal nutritional inadequacy was associated with increased nuclear abnormalities in newborns, suggesting an impact on fetal genomic stability.

Potassium bromate (KBrO3), classified as a probable human carcinogen, has long been used as a flour-improving and oxidizing agent in baking and food processing industries. It is also generated as a by-product during ozonation of drinking water, raising concerns about widespread, low-dose exposure. Experimental studies consistently demonstrate that KBrO3 induces multiple-organ toxicity primarily through oxidative stress-mediated mechanisms. Exposure to KBrO3 leads to excessive generation of reactive oxygen species, resulting in depletion of glutathione reserves, enhanced lipid peroxidation, and oxidative DNA damage. Such genotoxic effects include DNA strand breaks, micronuclei formation, and chromosomal aberrations, which collectively contribute to its well-documented carcinogenic and mutagenic potential. Consequently, these molecular alterations promote renal, hepatic, and thyroid tumor formation reported in experimental animal models, while emerging epidemiological evidence suggests possible associations between chronic dietary exposure to KBrO3 and gastrointestinal malignancies in humans. However, recent research has thoroughly investigated the chemopreventive potential of dietary antioxidants in mitigating KBrO3-induced toxicity, highlighting their ability to attenuate oxidative damage through enhancement of endogenous antioxidant defenses, modulation of the key cytoprotective signaling pathways and restoration of cellular redox homeostasis. With continued usage of KBrO3 and the inconsistency of regulatory enforcement worldwide, strengthening risk assessment, surveillance and preventive strategies-particularly the substitution of KBrO3 with safer alternatives and the promotion of antioxidant-rich diets is crucial to reduce long term carcinogenic risk and safeguard global public health.

Human exposure to nanoparticles (NPs) poses potential health risks that are modulated, for example, by the physico-chemical characteristics of NPs, the exposure route and the dose of NPs. Among 21 workers involved for many years in welding on metal surfaces and the machining of nanocomposites, we investigated the role of NPs in the induction of DNA damage. Blood samples of the exposed subjects were collected before and after their working shifts. The controls (21 individuals without occupational exposer to NPs) were sampled in parallel with the exposed ones. NP exposure concentrations were assessed using stationary and personal monitors. DNA damage, including oxidized bases and strand breaks (DNA-SB), in leukocytes was analyzed using Comet assay. The particles monitoring showed that machining was the dominant source of NPs. When compared with the controls, nanocomposite-exposed workers had significantly increased levels of both DNA damage types. In subjects performing machining, post-shift DNA-SB levels were significantly higher than those pre-shift. In welders, such an effect was not observed. Importantly, in both groups, levels of oxidatively damaged DNA were comparable in the post-shift vs. pre-shift samples. The lack of increased DNA oxidation in the post-shift samples suggests the induction of adaptive processes, probably related to long-term occupational exposure to NPs, that protect the organism against this type of DNA damage. However, despite this observation, the potential negative health impacts associated with NP inhalation cannot be ruled out.

Diet quality can be a potential modifier of post-acute COVID-19 syndrome (PACS), yet the relationship between dietary patterns, symptom burden, and biological markers remains poorly understood. We hypothesized that a low-quality diet would positively associate with PACS symptom burden, DNA damage, inflammatory and neurotrophic markers, and with overall health quality. A total of 186 individuals were classified into three groups: control (n = 64), acute PACS (n = 66), and chronic PACS (n = 55). Dietary intake was assessed by a food frequency questionnaire, and diet quality was quantified via the Protective and Risk Eating Score (PRES). Blood samples were analyzed for inflammatory (tumor necrosis factor-α, transforming growth factor-β, interleukin-6, interleukin-1β) and neurotrophic (brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor, S100 calcium-binding protein B) markers. DNA damage was assessed by micronuclei frequency, telomere length, and comet assay parameters. Health index (HI) was assessed by daily habits (alcohol consumption, sleeping patterns, hydration, exercise frequency, smoking habits, anthropometric parameters, and PRES). No significant differences were found among groups in ultra-processed foods or sugary products intake, PRES scores, inflammatory or neurotrophic biomarkers, DNA damage indicators, and HI. Of note, poorer diet quality was associated with higher symptom burden in PACS women, mainly in fatigue, memory, mental health, circulatory, and skin symptom domains. Few associations among diet quality, HI, and biomarkers emerged. Of note, principal component analysis shows that PACS relies on the convergence of genomic instability, systemic inflammation, and low diet quality. These findings suggest that diet may represent a modifiable factor in PACS management, warranting longitudinal and interventional studies to determine causality and therapeutic potential.

Previously, tetrazole-based Schiff base ligands (TBSL) and their Pt(II) complexes were synthesized and evaluated for cytotoxic activity. The results revealed that low cytotoxicity for the ligands and moderate effects for the Pt(II) complexes compared to cisplatin. Given these promising findings, the genotoxic potential of the Pt(II) complexes was further investigated. Genotoxicity was assessed using in vitro chromosomal aberration, micronucleus, and comet assays. The TBSL exhibited low genotoxicity, whereas the Pt(II) complexes induced higher genotoxic effects; however, these effects were lower than those observed for cisplatin. The low cytotoxic and genotoxic profiles of TBSL support their consideration for further pharmaceutical evaluation. In addition, the genotoxicity findings suggest that the Pt(II) complexes merit further investigation in the context of antitumor drug development.