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Query: "author" (Bojana Žegura) .

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1.
Načrt za ravnanje z raziskovalnimi podatki
Marta Sendra, Martina Štampar, Bojana Žegura, 2025, other monographs and other completed works

Abstract: Načrt za ravnanje z raziskovalnimi podatki za projekt "Prekinitev plastične verige: Razkrivanje poti in celičnih odzivov na okoljsko starano nanoplastiko (NanoBreak)".
Keywords: NanoBreak, Danio rerio, inducirane pluripotentne matične celice, človeški jetrni organoid, mikroplastika, nanoplastika, projekti
Published in DiRROS: 22.12.2025; Views: 442; Downloads: 101
.pdf File (432,89 KB)

2.
Hazard identification and characterization of leachable chemicals from plastic products – a new PARC project
Hubert Dirven, Nina Franko, Marija Sollner Dolenc, Tim Ravnjak, Martina Štampar, Bojana Žegura, 2025, review article

Abstract: A recent study has suggested that plastics may contain more than 16,000 chemicals, including additives, processing aids, starting substances, intermediates and Non-Intentionally Added Substances. Plastic chemicals are released throughout the plastic life cycle, from production, use, disposal and recycling. Most of these chemicals have not been studied for potential hazardous properties for humans and in the environment. To refine the risk assessment of these leachable chemicals, additional hazard data are needed. The PlasticLeach project within the EU co-funded Partnership for the Assessment of Risks from Chemicals (PARC) aims to address this data gap by screening several plastic products in daily use. Leachates will be prepared from a number of these plastic items, and these chemical mixtures will be further tested using several test guideline compliant assays and New Approach Methodologies covering both human health and environmental endpoints. The most toxic leachates will be characterized using a non-targeted analysis pipeline to identify chemicals in the leachate. When single chemicals of concern are identified, these will be further tested to determine hazardous properties and identify the respective potency factors to better understand their specific hazard profiles. A tiered approach for hazard testing will be followed. The experimental work will be complemented by in silico toxicological profiling, using publicly available toxicity databases and tools, including Artificial Intelligence tools that cover both human and environmental endpoints. A comprehensive array of endpoints, including cytotoxicity, endocrine disruption, genotoxicity, immunotoxicity, reproductive toxicity and effects related to ecotoxicity will be evaluated. In this paper, we outline the plastic products to be tested and the battery of assays that will be used to identify hazards relevant to both human health and the environment. Data generated from in silico, in vitro, and in vivo approaches will be reported using standardized formats, stored within a centralized repository, and harmonized to adhere to the FAIR data principles (Findable, Accessible, Interoperable, and Reusable). This integrated strategy will not only advance our understanding of the risks associated with plastic-derived chemicals but will also provide critical support for regulatory decision-making and facilitate the development of safer, and more ecofriendly plastic materials in the future.
Keywords: plastics, chemicals, leachables, PARC, new approach methodologies, hazard assessment, toxicity, risk assessment
Published in DiRROS: 19.12.2025; Views: 187; Downloads: 92
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3.
CutCancer Final Conference 2025 : shaping tomorrow
2025, other monographs and other completed works

Keywords: genetska toksikologija, citogenetika, raziskave raka, biologija raka, zborniki, znanstvena posvetovanja
Published in DiRROS: 16.10.2025; Views: 468; Downloads: 163
.pdf Full text (3,37 MB)

4.
Deregulations of DNA damage-responsive genes, genes involved in the endocrine system, in an advanced in vitro 3D zebrafish hepatic cell model after exposure to Bisphenol A (BPA) and its emerging alternatives BPAF, BPAP and BPPH : version v1
Alja Štern, Špela Rozman, Bojana Žegura, 2025, complete scientific database of research data

Abstract: Bisphenol AF (BPAF), Bisphenol AP (BPAP), and Bisphenol PH (BPPH) are being introduced into consumer products to replace BPA and are subsequently detected in ecosystems. This study investigates the genotoxic and endocrine-disruptive potential of these emerging bisphenols using a 3D in vitro liver spheroid model derived from Danio rerio (ZFL cell line), on the transcriptional level. The selected genes targeted DNA damage response pathways (TP53, NER, BER) and endocrine-related signalling (Table 1). ZFL spheroids were prepared by a force floating method as described by Štampar et al. (2019)1. Four-day-old ZFL spheroids were exposed to BPA (50 and 200 µM), BPAF (25 and 100 µM), BPAP (25 and 100 µM), and BPPH (10 and 50 µM) for 24 (Table 2) and 96 (Table 3) hours. Following exposure, total RNA was extracted using the RNeasy® Mini Kit (Qiagen, Germany). RNA quality and quantity were assessed prior to reverse transcription (Applied Biosystems, USA), followed by gene-specific preamplification (TATAA PreAmp GrandMasterMix, Tataa Biocenter, Sweden). Gene expression analysis was performed using TaqMan Gene Expression Assays (Applied Biosystems, USA) on the Fluidigm One 48.48 Dynamic Array IFC microfluidic system as described by Štern et al. (2024)2. The generated data was analysed using the Fluidigm Gene Expression Analysis Software and with a free-accessible web program, quantGenious3. The difference in gene expression greater than 1.5-fold was considered a biologically important up/downregulation (relative expression >1.5 or <0.66, respectively). Statistically significant differences were analysed using ANOVA and Dunnett’s multiple comparison test in GraphPad Prism v9 (GraphPad Software, San Diego, CA, USA).
Keywords: bisphenols, genotoxicity, endocrine disruption, ZFL spheroids, gene expression, data
Published in DiRROS: 30.09.2025; Views: 339; Downloads: 215
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5.
Exploring the genotoxic potential of Bisphenol A and its emerging alternatives in an advanced in vitro 3D zebrafish hepatic cell model
Alja Štern, Katja Kološa, Špela Rozman, Bojana Žegura, 2025, original scientific article

Abstract: With global restrictions on Bisphenol A (BPA), various BPA alternatives are increasingly found in ecosystems, raising concerns. This study focuses on the genotoxic potential of three emerging BPA alternatives — Bisphenol AF (BPAF), Bisphenol AP (BPAP), and Bisphenol PH (BPPH) — using an advanced in vitro 3D model system, spheroids, prepared from a Zebrafish (Danio rerio) liver cell line (ZFL). Their cytotoxicity was evaluated using the CellTiter-Glo® 2.0 assay, while their genotoxic potential was assessed using the comet assay, γH2AX assay, and toxicogenomic analysis. The BPA alternatives were more cytotoxic to ZFL spheroids than BPA. Non-cytotoxic concentrations caused transient DNA damage without a significant increase in DNA double-strand breaks (DSBs). The toxicogenomic analysis confirmed these findings, indicating activation of the TP53 DNA damage response pathway, the nucleotide excision repair (NER) and base excision repair (BER) mechanisms, likely in response to bulky DNA lesions and oxidative DNA damage. In addition, the gene expression analysis indicated the influence of the tested BPs on the endocrine system. Our results indicate that BPAF, BPAP and BPPH have considerable genotoxic potential and pose a significant ecotoxicological risk, underscoring the need for further investigation and careful consideration of these chemicals as BPA replacements.
Keywords: BPA, BPAF, BPAP, BPPH, cytotoxicity, genotoxicity, ZFL spheroids
Published in DiRROS: 26.09.2025; Views: 330; Downloads: 149
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6.
Antigenotoxic effects of Tartary and common buckwheat extracts, rutin, and quercetin on DNA damage induced by the dietary mutagen acrylamide
Maja Vogrinčič, Bojana Žegura, 2025, original scientific article

Abstract: The antigenotoxic effects of methanolic extracts of Tartary (Fagopyrum tataricum Gaertn.) and common buckwheat (Fagopyrum esculentum Moench) flour were evaluated against acrylamide-induced DNA damage. Acrylamide, a toxic food contaminant, was first identified in 2002 following its detection in Swedish food products. Our findings demonstrate that extracts from both buckwheat species significantly reduced DNA strand breaks. Tartary buckwheat contains higher levels of rutin, quercetin, and polyphenols, and exhibits greater antioxidant activity compared to common buckwheat. Due to endogenous rutin-degrading glucosidase activity, part of the rutin was enzymatically converted into quercetin. Processing generally decreased antioxidant activity, with the exception of wheat bread, where a slight increase was observed, likely attributed to Maillard reaction products. We confirmed that acrylamide induces genotoxic effects in HepG2 cells at all tested concentrations (0.3125, 0.625, 1.25, and 2.5 mM) after 24 hours of exposure, and that methanolic buckwheat extracts effectively reduced the formation of acrylamide-induced DNA damage. The extract from Tartary buckwheat demonstrated the highest antigenotoxic activity, surpassing even pure rutin or quercetin at higher concentrations. These results suggest that although thermal processing can generate potentially harmful compounds, such as acrylamide, food matrices may simultaneously contain bioactive components capable of counteracting or mitigating such adverse effects.
Keywords: common buckwheat, Tartary buckwheat, DNA damage, acrylamide, antigenotoxic
Published in DiRROS: 25.09.2025; Views: 378; Downloads: 132
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7.
Volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) in indoor environments: a review and analysis of measured concentrations in Europe
Nikolina Račić, Ivana Terzić, Nina Karlović, Anja Bošnjaković, Teo Terzić, Ivana Jakovljević, Gordana Pehnec, Tajana Horvat, Goran Gajski, Bojana Žegura, 2025, review article

Abstract: Indoor air quality is a significant aspect of public health, yet it remains less studied than outdoor air pollution. Understudied indoor pollutants include volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). This review focuses on these two groups of compounds known for their health effects, including respiratory issues, neurological disorders, and carcinogenicity. We systematically compiled and analyzed data from studies reporting measured concentrations of VOCs and PAHs in European indoor environments—homes, schools, and offices—published in the past two decades. Concentration levels vary substantially across studies, influenced by regional differences, climate, building type, ventilation systems, and indoor activities. Identified sources include tobacco smoke, cooking, heating (e.g., biomass burning), and off-gassing from construction and furnishing materials. Our analysis reveals clear geographic patterns: lower concentrations of VOCs and PAHs are consistently reported in Northern and Western European countries, likely due to stricter air quality regulations, cleaner outdoor air, greater use of electric heating, and more advanced ventilation systems. Conversely, higher concentrations are more commonly observed in Southern and Eastern Europe, where biomass heating and poorer ventilation remain more prevalent. Seasonal variation also has a significant role, with higher indoor levels typically measured during colder months due to increased heating and reduced air exchange. This highlights the need for improved indoor air quality management practices and regulatory standards to minimize the health risks associated with VOCs and PAHs. This review of 46 scientific publications is aimed at informing future studies and guiding future field measurements and risk assessments in epidemiological studies.
Keywords: health risks, indoor air quality, PAHs, public health, VOCs
Published in DiRROS: 08.09.2025; Views: 458; Downloads: 180
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8.
Insights into chemopreventive effects of rosmarinic acid against aflatoxin B1-induced genotoxic effects
Veronika Furlan, Matjaž Novak, Martina Štampar, Alja Štern, Bojana Žegura, Urban Bren, 2025, original scientific article

Abstract: In this study, the chemopreventive effects of rosmarinic acid (RA), a major phenolic acid of the plant Rosmarinus officinalis L., against the carcinogenic naturally occurring mycotoxin aflatoxin B1 (AFB1) were investigated using both in silico and in vitro approaches. The in silico investigation of the chemical reactions between rosmarinic acid and the carcinogenic metabolite of AFB1, aflatoxin B1 exo-8,9-epoxide (AFBO), was conducted by activation free energies calculations with DFT functionals M11-L and MN12-L, in conjunction with the 6-311++G(d,p) flexible basis set and implicit solvation model density (SMD), according to a newly developed quantum mechanics-based protocol for the evaluation of carcinogen scavenging activity (QM-CSA). Following the computational analyses, the chemoprotective effects of RA were further studied in vitro in human hepatocellular carcinoma HepG2 cells by analyzing its influence on AFB1-induced genotoxicity using a comet assay, γH2AX, and p-H3, while its impact on cell proliferation and cell cycle modulation was assessed using flow cytometry. Our computational results revealed that the activation free energy required for the reaction of RA with AFBO (14.86 kcal/mol) is significantly lower than the activation free energy for the competing reaction of AFBO with guanine (16.88 kcal/mol), which indicates that RA acts as an efficient natural scavenger of AFBO, potentially preventing AFB1-specific DNA adduct formation. The chemoprotective activity of RA was confirmed through in vitro experiments, which demonstrated a statistically significant (p < 0.05) reduction in AFB1-induced single- and double-strand breaks in HepG2 cells exposed to a mixture of AFB1 and RA at non-cytotoxic concentrations. In addition, RA reversed the AFB1-induced reduction in cell proliferation.
Keywords: rosmarinic acid, aflatoxin B1, chemopreventive effects, antigenotoxic effects, density functional theory, chemical carcinogen scavenger, toxicology
Published in DiRROS: 03.07.2025; Views: 583; Downloads: 449
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9.
Nano spray-dried particles of in-situ crosslinked alginate and their toxicological characterisation
Jaka Levanič, Ilja Gasan Osojnik Črnivec, Iza Rozman, Mihaela Skrt, Alja Štern, Bojana Žegura, Nataša Poklar Ulrih, 2024, original scientific article

Abstract: The feasibility and technical capacity for producing crosslinked sub-micron gels with a nano spray-dryer were studied with variable pH systems incorporating alginate, pectin, and pullulan. The obtained powders were characterized for their morphology, particle size distribution, and their toxicological safety profile using genotoxicity and cytotoxicity assays. Additionally, quercetin was added to the encapsulation system to study the potential of the system to encapsulate this material. The produced powders exhibited morphologies and particle size distributions characteristic for nano spray-drying. The addition of pullulan and pectin to the feed solutions resulted in a particle size increase, with crosslinked alginate particles having a mean value of 1.43 μm, while particles with added pectin and pullulan had a mean particle size of 1.70 and 1.75 μm, respectively. The inclusion of quercetin proved to be problematic with this encapsulation system. Extremely high degradation rates and extremely low encapsulation efficiencies were observed due to the alkaline pH (~10) of the system that is needed to keep the feed dispersion in a liquid state and prevent premature crosslinking of the alginate. Although pectin and pullulan provided some protection for quercetin in the alkaline dispersion, the absolute quercetin content in the final product remained very low, with a maximum achieved encapsulation efficiency of 2.06 %. The safety profile of most produced powders was favourable, as they did not exhibit any significant cytotoxic and genotoxic activity in the HepG2 cell line, except in the case of Alginate/Pullulan which showed a 43 % decrease in cell viability at 500 μg/mL. Samples where quercetin was added did not show any increased toxicological effect.
Keywords: alginate, polysaccharides, crosslinking, nano spray drying, toxicological evaluation
Published in DiRROS: 08.05.2025; Views: 779; Downloads: 478
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10.
Hazard characterization of the mycotoxins enniatins and beauvericin to identify data gaps and improve risk assessment for human health
Anne-Cathrin Behr, Christiane Kruse Fæste, Amaya Azqueta, Ana P. M. Tavares, Anastasia Spyropoulou, Anita Solhaug, Ann-Karin Olsen, Ariane Vettorazzi, Bojana Žegura, Matjaž Novak, 2025, review article

Abstract: Enniatins (ENNs) and beauvericin (BEA) are cyclic hexadepsipeptide fungal metabolites which have demonstrated antibiotic, antimycotic, and insecticidal activities. The substantial toxic potentials of these mycotoxins are associated with their ionophoric molecular properties and relatively high lipophilicities. ENNs occur extensively in grain and grain-derived products and are considered a food safety issue by the European Food Safety Authority (EFSA). The tolerable daily intake and maximum levels for ENNs in humans and animals remain unestablished due to key toxicological and toxicokinetic data gaps, preventing full risk assessment. Aiming to find critical data gaps impeding hazard characterization and risk evaluation, this review presents a comprehensive summary of the existing information from in vitro and in vivo studies on toxicokinetic characteristics and cytotoxic, genotoxic, immunotoxic, endocrine, reproductive and developmental effects of the most prevalent ENN analogues (ENN A, A1, B, B1) and BEA. The missing information identified showed that additional studies on ENNs and BEA have to be performed before sufficient data for an in-depth hazard characterisation of these mycotoxins become available.
Keywords: enniatins, beauvericin, genotoxicity, endocrine effects, immunotoxicology, toxicokinetics
Published in DiRROS: 14.04.2025; Views: 686; Downloads: 309
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