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Increased industrial offshore activities in northern waters raise the question of impact of polycyclic aromatic hydrocarbons (PAHs) on key Arctic marine species. One of these is the ecologically important polar cod (Boreogadus saida), which is the primary food source for Arctic marine mammals and seabirds. In the present work, we have conducted the first comprehensive proteomics study with this species by exploring the effects of dietary PAH exposure on the hepatic proteome, using benzo[a]pyrene (BaP) as a PAH model-compound. Functional annotation and pathway analyses of the proteins affected by BaP revealed a concerted cellular response for handling and adopting to its exposure, involving numerous interconnected signalling pathways and metabolic processes. In accordance with BaP being a strong aryl hydrocarbon receptor (Ahr) agonist, a prominent activation of the canonical Ahr signalling pathway was observed, including upregulation of Ahr target proteins like cytochrome P450 enzymes and microsomal glutathione transferase. Furthermore, cellular pathways for handling oxidative stress, protein misfolding and degradation, as well as endoplasmic reticulum stress and calcium homeostasis, were also activated by BaP, possibly as a result of the formation of harmful and redox reactive BaP metabolites via phase I metabolism. Activation of proteins that participate in the acute-phase response was also observed, suggesting prevalent tissue- and cellular damage that triggers the immune system and inflammatory responses. Our results at the protein level aligns well with previous analyses on the effects of BaP on the polar cod liver transcriptome and support that exposure to BaP and structural similar PAHs can cause adverse effects on polar cod physiology. Although more data is required for demonstrating how these molecular responses propagate to higher levels of biological organisation, increased knowledge about the initial cellular and molecular mechanisms that induce toxicity is a key-step towards a mechanistically informed impact assessment of PAH pollutants in the Arctic., Competing Interests: Declaration of competing interest The author JD Rasinger declares that he is currently employed with the European Food Safety Authority (EFSA) in the Food Ingredients and Packaging Unit (FIP), which provides scientific and administrative support to the Panel on Food Additives and Flavourings. However, the present article is published under the sole responsibility of the author JD Rasinger and may not be considered as an EFSA scientific output. The positions and opinions presented in this article are those of the author alone and are not intended to represent the views/any official position of EFSA. To know about the views or scientific outputs of EFSA, please consult its website. The author's main contributions to this article were made before joining EFSA when still employed at the Institute of Marine Research. The author A Goksøyr is a major shareholder in Biosense Laboratories AS, supplier of the Atlantic cod anti-Cyp1a polyclonal antibody., (Copyright © 2025 The Authors. Published by Elsevier B.V. All rights reserved.)

Benzo(a)pyrene (BaP), a pervasive environmental pollutant with endocrine-disrupting properties, has been associated with detrimental effects on pregnancy. During early pregnancy, the endometrial decidualization process is critical for embryo implantation. Abnormal decidualization can lead to implantation failure, aberrant placental formation, and pregnancy loss. We previously revealed that BaP exposure impaired decidualization and implantation in mice, yet the underlying mechanisms remained elusive. Autophagy, a cellular mechanism pivotal for energy and material recycling, contributes to the decidualization process. The chemokine C-X-C motif chemokine ligand 12 (CXCL12), secreted by endometrium stromal cells (ESCs), is involved in regulating endometrial decidualization and autophagy. Therefore, this study aimed to explore the hypothesis that BaP disrupts the decidualization process by interfering with autophagic pathways via the CXCL12/CXCR4 axis during early pregnancy. We found that BaP inhibited CXCL12/CXCR4 expression, and induced autophagy by promoting autophagosome formation, which in turn impaired the decidualization in early pregnant mice uterus and decidual stromal cells (DSCs). Using autophagy inhibitors 3-methyladenine and chloroquine in combination with BaP to treat DSCs, successfully weakened BaP-induced autophagy, and relieved decidual injury. Additionally, activation of CXCL12/CXCR4 by recombinant protein CXCL12 attenuated BaP-induced autophagy, inhibited the PI3K/AKT signal activation caused by BaP, and partly rescued the expression of decidualization-related genes. In summary, this study demonstrates that BaP induces autophagy in DSCs by inhibiting the CXCL12/CXCR4 axis, leading to damage in endometrial decidualization during early pregnancy. The findings provide a critical chemokine-mediated regulatory mechanism involved in embryo implantation and contribute valuable knowledge to the reproductive toxicology of BaP., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Mutagenicity testing is a component of the hazard assessment of industrial chemicals, biocides, and pesticides. Mutations induced by test substances can be detected by in vitro and in vivo methods that have been adopted as OECD Test Guidelines. One of these in vivo methods is the Transgenic Rodent Assay (TGRA), OECD test guideline no. 488. An analogous in vitro TGRA has been described, but experience with this test method is limited. In this study, six in vivo TGRA positive mutagens were tested in the in vitro TGRA based on primary MutaMouse hepatocytes. In addition to the functional read-out of the lacZ reporter gene, induced mutations were analysed by next-generation sequencing (NGS). Five of the six in vivo TGRA positive mutagens (N-ethyl-N-nitrosourea (ENU), ethyl methanesulfonate (EMS), mitomycin C (MMC), benzo[a]pyrene (B[a]P), and azathioprine (AZA), but not cyproterone acetate) mutated the lacZ gene in vitro. NGS identified mutations which matched the mutagenic mechanisms described in the literature. The alkylating agent ENU induced a greater proportion of A:T to T:A transversions than did the other alkylating agent, EMS, whereas EMS increased smaller deletions (1-4 bp). G:C to T:A transversions accounted for the majority of mutations identified after treatments with MMC and B[a]P, both of which form monoadducts at the guanine N2 position. AZA induced mainly G:C to A:T transitions, explained by the structural similarity of one of its metabolites to guanine. An increased proportion of mid-size changes (0.3-2.5 kb) was detected only for the crosslinking mutagen MMC. The in vitro TGRA based on primary MutaMouse hepatocytes is a promising in vitro assay for the assessment of mutation induction, reflecting many aspects of the corresponding in vivo TGRA and allowing for mutation spectra analysis to evaluate the induced mutations., Competing Interests: Declaration of Competing Interest Alina Göpfert, Claudia Rülker, Michael Eichenlaub, Bogdan Tokovenko, Martina Dammann, Dorothee Funk-Weyer, Naveed Honarvar and Robert Landsiedel are employees of BASF SE, a chemical company which may use the assay to develop and register commercial products., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Although humans are frequently exposed to multiple pollutants simultaneously, research on their harmful effects on health has typically focused on studying each pollutant individually. Inorganic arsenic (As) and benzo[a]pyrene (BaP) are well-known pollutants with carcinogenic potential, but their co-exposure effects on breast cancer cell progression remain incompletely understood. This study aimed to assess the combined impact of BaP and As on the viability and migration of MDA-MB-231 cells. The results indicated that even at low levels, both inorganic As (0.01 μM, 0.1 μM, and 1 μM) and BaP (1 μM, 2.5 μM), individually or in combination, enhanced the viability and migration of the cells. However, the cell cycle analysis revealed no significant differences between the control group and the cells exposed to BaP and As. Specifically, exposure to BaP alone or in combination with As (As 0.01 μM + BaP 1 μM) for 24 h led to a significant increase in vimentin gene expression. Interestingly, short-term exposure to As not only did not induce EMT but also modulated the effects of BaP on vimentin gene expression. However, there were no observable changes in the expression of E-cadherin mRNA. Consequently, additional research is required to evaluate the prolonged effects of co-exposure to As and BaP on the initiation of EMT and the progression of breast cancer., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

To study the intricate toxicological mechanisms triggered by exposure to mixed pollutants, we exposed zebrafish embryos to legacy and emerging pollutants through binary mixtures of benzo[a]pyrene (B[a]P) and diclofenac (DFC). The combination of next-generation transcriptomics and toxicopathology disclosed instances where exposure to mixtures did not attain the expected sum of acute effects of individual toxicants, indicating potential antagonism. Despite overall higher mortality in DFC treatments, the same antagonistic trend was noted in genotoxicity and molecular pathways related to RNA turnover, cell proliferation, apoptosis and cell-cycle control. The formation of oedemas in the heart cavity and yolk sac can be an adverse outcome (AO) resulting from exposure to DFC isolated or combined, whose potential key events (KEs) may involve cell cycle arrest and apoptosis via p53 and MAPK pathways. From the findings it can be hypothesised that, rather than genotoxicity, the molecular initiating event (MIE) maybe inflammation triggered by oxidative stress. Nonetheless, the exact role of ROS in the process needs further clarification. Impaired eye function by action of DFC and B[a]P combined may be another AO, in the case caused by ocular degeneration following the suppression of biologic processes and molecular functions involved in eye development and its functionalities, possibly linked to hindered regulation of the expression of hsf4 and cryaa. Altogether, toxicopathology suggests predominance of antagonistic effects, but its integration with mechanism suggests that interactions between DFC and B[a]P in environmentally-relevant concentrations that may lead to hindrance of key functions such as the control of inflammation and cell cycle. These outcomes suggest potentially severe implications for health and survival, in case of prolonged chronic exposure to combined toxicants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Benzo[a]pyrene (B[a]P) is a well-known polycyclic aromatic hydrocarbon (PAH) pollutant with high carcinogenicity, widespread environmental presence, and significant threat to public health. Epidemiological studies have linked exposure to B[a]P and its metabolite 7,8-dihydroxy-9,10-epoxybenzo[a]pyrene (BPDE) to the development and progression of various cancers, including bladder cancer. However, its underlying mechanism remains unclear. Our study revealed that B[a]P and BPDE induced epithelial-mesenchymal transition (EMT), a critical early event in cell malignant transformation, involving a decrease in E-Cadherin and upregulation of N-Cadherin protein levels, leading to increased cell motility and migration in bladder epithelial cells. Further studies have indicated that LOXL1 DNA undergoes methylation and modification influenced by methyltransferase 3a (DNMT3a) and DNMT3b, resulting in decreased LOXL1 protein levels. The decreased LOXL1 promotes the zinc finger transcription factor SLUG, which then inhibits E-Cadherin protein levels and initiates the EMT process. Moreover, DNMT3a/3b expression appears to be influenced by intracellular oxidative stress levels. These findings suggest that exposure to B[a]P/BPDE promotes the EMT process through the pivotal factor LOXL1, thereby contributing to bladder carcinogenesis. Our study provides a theoretical basis for considering LOXL1 as a potential biomarker for early diagnosis and a novel target for the precise diagnosis and treatment of bladder cancer., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Persistent organic pollutants (POPs) are easily accumulated in organisms due to its high lipophilicity. Bivalves are still one of the marine invertebrates with high species diversity despite experiencing with environmental pollution. However, studies investigating the adaptation mechanisms of bivalves towards POPs have been lacking. In this study, we chose benzo[a]pyrene (B[a]P), a typical POPs, to investigate the accumulation and excretion mechanism of clam Ruditapes philippinarum towards B[a]P. Laser confocal microscopy images of ovaries and testes confirmed significant colocalization between lipid droplets and B[a]P. However, B[a]P in the testes might mainly excrete with the excretory fluid. Furthermore, lipidomics results indicated that the upregulated TGs were TGs with 48-58 total carbon atoms and 6-12 double bonds in acyl side chains in ovaries, while the upregulated TGs mainly distributed in 48-58 total carbon atoms and 4-14 double bonds in acyl side chains in testes. In ovaries, gene expression of lipid metabolism and phospholipid metabolism basically presented an upward trend at Pro and Mat stages, while entirely performed a downregulation trend at Gro stage. Testes had the opposite regulation with that. Additionally, B[a]P prompted the excretion ability of female clams, but exhibited a complex effect in the male. This study provides a scientific basis for bivalve toxicology and healthy aquaculture, which is of great significance for marine ecological environment protection and aquatic product safety of China., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The effects of B[a]P and Cd on the growth, free-radical metabolism, antioxidants, and photosynthetic fluorescence parameters of Poa pratensis were studied by pot experiments. Results showed that low-concentration Cd (≤ 10 mg·kg - 1 ) increased fresh weight, dry weight, malondialdehyde, superoxide anion radical, glutathione, and ascorbic acid. Conversely, high-concentration Cd (≥ 50 mg·kg - 1 ) significantly decreased the fresh weight and dry weight, photosynthetic gas exchange, and fluorescence parameters. Water-use efficiency increased by 1.55 times compared with the control at high concentrations of B[a]P (≥ 25 mg·kg - 1 ) and Cd (≥ 50 mg·kg - 1 ). Principal component analysis showed that Cd played an important role in co-pollution. P. pratensis mitigated B[a]P and Cd co-contamination toxicity by regulating antioxidant activity and water-use efficiency. P. pratensis can tolerate 1, 5, and 25 mg·kg - 1 B[a]P, as well as 1 and 10 mg·kg - 1 Cd. P. pratensis was also highly capable of degrading B[a]P and extracting Cd in soils co-contaminated with B[a]P and Cd., Competing Interests: Declarations. Competing Interests: No potential conflict of interest was reported by the author., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Benzo[a]pyrene (BaP), a major harmful component in PM2.5, is widely present in automobile emissions and atmospheric pollution. BaP exposure directly targets the lungs, often resulting in acute lung injury (ALI). However, comprehensive metabolic and transcriptomic profiles related to BaP-induced ALI remain unexplored. To simulate BaP-induced lung injury, we performed intratracheal instillation of BaP. To investigate how BaP exposure affects lung transcriptome and metabolic profiles, we used RNA sequencing and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). We aimed to understand the underlying mechanisms of BaP-induced lung damage. Metabolomics analyses indicated that in BaP-exposed animals, most fatty acids, carbohydrates, and steroids were significantly reduced, whereas most amino acids and organic acids remained unchanged. Analysis of transcriptomics data showed that fatty acid synthesis decreased and fatty acid oxidation increased, suggesting that lipid breakdown occurs after BaP exposure. Additionally, there were increases in oxidative stress system activity and decreases in immune system function. Finally, BaP altered mitochondrial, lipid, immune system, and fatty acid pathways, as indicated by pathway enrichment analyses. These results show that BaP substantially affects metabolic and inflammatory responses, enhancing the broader understanding of the underlying mechanisms of ALI after BaP exposure., Competing Interests: Declaration of Competing Interest The authors have no relevant financial or non-financial interests to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The deleterious health impacts of polycyclic aromatic hydrocarbons (PAHs) on the population have been extensively substantiated and acknowledged. Mounting evidence underscores that PAH exposure is closely linked to an elevated risk of mental disorders, particularly in populations experiencing occupational and high-level exposure. In this study, we aimed to investigate the mechanisms underlying anxiety-like behaviors induced by different dosages of PAHs, with a concentrated focus on brain region-specific metabolic alterations in mice using various metabolomics approaches. Male C57BL/6 mice were exposed to benzo[a]pyrene (B[a]P), a typical PAH, through gavage at occupational exposure and EPA toxicologically relevant dosages (2.0 and 20.0 mg/kg/day) for 21 days, respectively. Behavioral assessments revealed that occupational exposure to B[a]P induced anxiety-like behaviors in C57BL/6 mice. Meanwhile, elevated serum norepinephrine and corticotropin-releasing hormone further confirmed the anxiety-inducing effects of B[a]P exposure. Metabolomics analysis uncovered dysregulation across various metabolic pathways following B[a]P exposure, encompassing brain neurotransmitter, organic acid, amino acid, lipid, fatty acid, and cholesterol. Anxiety levels and lipid metabolic abnormalities were notably exacerbated at the higher dosage, despite being only a 10-fold increase. Of particular significance, a decrease in lysophosphatidic acid (LPA) and lysophosphatidylserine (LPS) emerged as pivotal indicators of B[a]P neurotoxicity. Spatial-resolved metabolomics further demonstrated distinctive lipid and metabolite profiles across different brain subregions after exposure to B[a]P. Remarkably, alterations were specifically observed in the anxiety-related brain regions, such as the hippocampus, cortex, white matter, and thalamus, varying with exposure dosages. These findings underscore the significance of brain metabolic abnormalities in the development of mental disorders triggered by B[a]P exposure and highlight the need for establishing precise exposure limits of B[a]P to safeguard public mental health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Toxicant-induced behavioural changes provide important insights into environmental toxicity, particularly in vulnerable tropical marine habitats. However, ecotoxicological knowledge of organisms in these environments is insufficient. We aimed to develop innovative and cost-effective ecotoxicology methods using Parhyale hawaiensis as a tropical model organism. Adult P. hawaiensis were exposed to aqueous benzo[a]pyrene (BaP) (2 μM) and dietary BaP (50, 250, or 1250 μg BaP/g diet). Survival (24 to 96 h) and behavioural responses (21d) to foraging, reproduction, and predator avoidance were studied. Aqueous and dietary exposures to benzo[a]pyrene (BaP) did not affect survival but induced significant immobility with effective concentration (EC 50  ± SE, 96 h at 11.89 ± 1.19 μM). Relative to the control group, aqueous exposure to 2 μM and dietary exposure to 250 and 1250 μg BaP/g feed resulted in statistically significant behavioural changes. These included a 55-76 % reduction in feeding rates, 133 % increase in chemosensation time, 60-122 % drop in moulting frequency, 200 % delay in precopulatory activity, 50-83 % decrease in geotactic activity, and 300-400 % increase in phototactic activity (all significant at p ≤ 0.05). The methods developed in this study are cost-effective, sensitive, and readily integrated into other endpoint analyses, reinforcing the potential of P. hawaiensis as a tropical ecotoxicology model for detecting toxicant-induced behavioural responses and enhancing marine risk assessments., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ibrahim Lawan reports financial support was provided by Petroleum Technology Development Fund (PTDF) of Nigeria. Ibrahim Lawan reports a relationship with Petroleum Technology Development Fund (PTDF) of Nigeria that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Context: Plant microRNAs (miRNAs) present in Yishen Tongluo formula (YSTL, a traditional Chinese herbal medicine formula) are considered as potential therapeutic drugs for reducing the sperm DNA fragmentation index (DFI)., Objective: To study the effectiveness of plant miRNAs in YSTL for repairing mouse sperm DNA damage caused by benzo( a )pyrene (BaP)., Methods and Materials: Twenty-four male SPF ICR (CD1) mice were divided into control, BaP and YSTL groups. A BaP-induced (100 mg/kg) sperm DNA damage model was established in the BaP and YSTL groups, and the mice in the YSTL group were treated with YSTL (23.78 g/kg) for 8 weeks. Sperm DFI was determined via a sperm chromatin structure assay (SCSA). MicroRNAs in the testes of the mice were analysed via RNA-seq, and the top four plant miRNAs were screened, identified and overexpressed in GC cells. The effects of plant miRNAs on the viability and DNA integrity of GC cells exposed to benzo( a )pyrene diol epoxide (BPDE) (1 μM) were tested using CCK8 and comet assays., Results: Compared with that of the BaP group, the DFI of the YSTL group decreased (9.57% vs. 18.54%, F  = 18.645, p  = 0.0236). miR166-y, miR894-x, miR822-x and miR396-x were screened. The CCK8 and comet assays revealed that the DFI of the mimic group was significantly lower than that of the BPDE (IC 50 = 1.006 μM) group, with the most significant difference in the miR396-x group., Discussion and Conclusions: Plant miRNAs such as miR396-x can penetrate the blood-testis barrier through the digestive system to repair sperm DNA.

Road traffic is a major contributor to air pollution and consequently negatively affects human health. Car pollution originates both from exhaust emissions (EE) and non-exhaust emissions (NEE, such as tire and brake wear particles, erosion of road surfaces and resuspension of road dust). While the toxicity of EE and NEE has been characterized separately, their combined effects are poorly documented. However, we are constantly exposed to a mixture of pollutants and their interactions should not be neglected as they may significantly impact their toxicological profile resulting in additive, synergistic or antagonistic effects. To fill this gap, we investigated in vitro the combined toxicity of exhaust gases and benzo[a]pyrene (representative of EE) and tire particles (representative of NEE). Macrophages from the RAW264.7 cell line were exposed for 24 h to tire particles (TP) of variable size (6-113 µm), alone or in combination with exhaust gases (CO 2 , CO, NO, NO 2 ) and benzo[a]pyrene (B[a]P) as an archetype of polycyclic aromatic hydrocarbon (PAH). The cell response was assessed in terms of cytotoxicity, proinflammatory response and oxidative stress. TP, gases and B[a]P, alone or in combination triggered neither cytotoxicity nor oxidative stress. On the contrary, a proinflammatory response was elicited with two different profiles depending on the size of the TP: TNF-α production was either slightly (with the finest TP) or strongly (with coarse TP) increased in the presence of gases and B[a]P, suggesting that the effects of TP, gases and B[a]P were either additive or synergistic, depending on TP size., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests, Abderrahmane Bouredji reports financial support was provided by The French Agency for Ecological Transition. Bogdan Muresan reports a relationship with Michelin that includes: funding grants. Jeremie Pourchez reports a relationship with Michelin that includes: funding grants. Valerie Forest reports a relationship with Michelin that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon from incomplete combustion, builds up in coastal regions through river runoff, atmospheric deposition, and coastal activities. BaP's lipophilicity and stability lead to persistent environmental impacts due to its resistance to degradation. The economically valuable golden cuttlefish, Sepia esculenta, often spawns and hatches in shallow waters, making it prone to BaP exposure. This study employs transcriptomic analysis to initially investigate juvenile golden cuttlefish's response to BaP. The results indicate that BaP exposure significantly affects various physiological and molecular functions of the juveniles, particularly affecting pathways related to immune and inflammatory responses, metabolic regulation, and nervous system functions. Functional enrichment and PPI network analyses identified key genes such as HSGALT-like, ASAH1-like, and GTL-like in the BaP response. These genes exhibited a suppressive trend during short-term exposure, indicating that BaP exposure may influence lipid metabolism, energy conversion, and digestive functions at the genetic level, which could further disrupt the overall physiological state and developmental processes of juvenile golden cuttlefish. The study offers novel insights into BaP's effects on juvenile golden cuttlefish and marine life, aiding marine ecosystem and biodiversity conservation., Competing Interests: Declaration of competing interest The corresponding author stated that all authors reported no potential conflicts., (Copyright © 2024 Elsevier Inc. All rights reserved.)

In vitro models based on permanent fish liver cell lines have proven to be versatile tools for examining chemical biotransformation and toxicity. However, their in vivo relevance remains uncertain due to their potentially de-differentiated phenotype. Here, we investigate whether a 3D cell culture environment can restore hepatocyte-like properties of the Rainbow trout liver cell line RTL-W1. Utilizing ultralow attachment (ULA) microwell plates, we achieved controlled sizing and extended culture (3 weeks) of spheroidal aggregate cultures (spheroids). RTL-W1 cells within the spheroids remained viable and metabolically active, as confirmed by the CellTiter-Glo 3D assay. Transmission electron microscopy revealed that spheroids exhibit tissue-like arrangements, such as interdigitations, cell-cell junctions, and endo- or exocytic activity at the cell-cell interface. They also displayed ultrastructural characteristics typical of metabolically active cells/hepatocytes, including abundant endoplasmic reticulum (ER), Golgi apparatus, and mitochondria. RT-qPCR analysis showed upregulation of genes involved in xenobiotic and endogenous (lipid) metabolism in 3D cultures over time. Notably, for several genes, especially cyp1a, expression levels were significantly higher in spheroids than in monolayers cultured for the same duration. This was corroborated at the enzyme level by increased Cyp1a-dependent catalytic activity (EROD). Interestingly, increased Cyp1a expression did not lead to heightened susceptibility to benzo[a]pyrene toxicity, which requires bioactivation. However, RTL-W1 3D and 2D cell cultures exhibited differential susceptibility to toxicity from other model chemicals, such as the surfactant SDS and the metal copper (Cu). These findings support the hypothesis that RTL-W1 cells can re-differentiate to a hepatocyte-like phenotype when cultured in a 3D configuration and may exhibit distinct biological responses upon exposure to xenobiotics. Overall, this study advances our understanding of the potential of cell line-derived 3D in vitro models for research and providing more physiologically relevant data for regulatory contexts., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Polycyclic aromatic hydrocarbons (PAHs), including the Group 1 human carcinogen benzo[a]pyrene (BaP), are produced by the incomplete combustion of organic matter and thus are present in tobacco smoke, charbroiled food and diesel exhaust. The nematode Caenorhabditis elegans is an established model organism, however it lacks the genetic components of the classical mammalian cytochrome P450 (CYP)-mediated BaP-diol-epoxide metabolism pathway. We therefore introduced human CYP1A1 or CYP1A2 together with human epoxide hydrolase (EPHX) into the worm genome by Mos1-mediated Single Copy Insertion (MosSCI) and evaluated their response to BaP exposure via toxicological endpoints. Compared to wild-type control, CYP-humanised worms were characterised by an increase in pharyngeal pumping rate and a decrease in volumetric surface area. Furthermore, BaP exposure reduced reproductive performance, as reflected in smaller brood size, which coincided with the downregulation of the nematode-specific major sperm protein as determined by transcriptomics (RNAseq). BaP-mediated reproductive toxicity was exacerbated in CYP-humanised worms at higher exposure levels. Collagen-related genes were downregulated in BaP-exposed animals, which correlate with the reduction in volumetric size. Whole genome DNA sequencing revealed a higher frequency of T > G (A > C) base substitution mutations in worms expressing human CYP1A1;EPHX which aligned with an increase in DNA adducts identified via an ELISA method (but not classical 32 P-postlabelling). Overall, the CYP-humanised worms provided new insights into the value of genome-optimised invertebrate models by identifying the benefits and limitations within the context of the (3Rs) concept which aims to replace, reduce and refine the use of animals in research., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: ‘The author(s) declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The manuscript contains experiments using invertebrate only; no vertebrates/human studies were included.’., (Copyright © 2024. Published by Elsevier Ltd.)

Infertility has gradually become a global health concern, and evidence suggests that exposure to environmental endocrine-disrupting chemicals (EDCs) represent one of the key causes of infertility. Benzo(a)pyrene (BaP) is a typical EDC that is widespread in the environment. Previous studies have detected BaP in human urine, semen, cervical mucus, oocytes and follicular fluid, resulting in reduced fertility and irreversible reproductive damage. However, the mechanisms underlying the effects of gestational BaP exposure on offspring fertility in male mice have not been fully explored. In this study, pregnant mice were administered BaP at doses of 0, 5, 10 and 20 mg/kg/day via gavage from Days 7.5 to 12.5 of gestation. The results revealed that BaP exposure during pregnancy disrupted the structural integrity of testicular tissue, causing a disorganized arrangement of spermatogenic cells, compromised sperm quality, elevated levels of histone modifications and increased apoptosis in the testicular tissue of F1 male mice. Furthermore, oxidative stress was also increased in the testicular tissue of F1 male mice. BaP activated the AhR/ERα signaling pathway, affected H3K4me3 expression and induced apoptosis in testicular tissue. AhR and Cyp1a1 were overexpressed, and the expression of key molecules in the antioxidant pathway, including Keap1 and Nrf2, was reduced. The combined effects of these molecules led to apoptosis in testicular tissues, damaging and compromising sperm quality. This impairment in testicular cells further contributed to compromised testicular tissues, ultimately impacting the reproductive health of F1 male mice., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Benzo(a)pyrene (BaP) is one of the most thoroughly studied polycyclic aromatic hydrocarbons(PAHs) and a widespread organic pollutant in various areas of human life. Its teratogenic, immunotoxic and carcinogenic effects on organisms are well documented and widely recognized by researchers. In the body, BaP is enzymatically converted to form a more active benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE). BaP/BPDE has the potential to trigger gene mutations, influence epigenetic modifications and cause damage to cellular structures, ultimately contributing to disease onset and progression. However, there are different points of view when studying epigenetics using BaP/BPDE. On the one hand, it is claimed in cancer research that BaP/BPDE contributes to gene hypermethylation and, in particular, induces the hypermethylation of tumor's suppressor gene promoters, leading to gene silencing and subsequent cancer development. Conversely, studies in human and animal populations suggest that exposure to BaP results in genome-wide DNA hypomethylation, potentially leading to adverse outcomes in inflammatory diseases. This apparent contradiction has not been summarized in research for almost four decades. This article presents a comprehensive review of the current literature on the influence of BaP/BPDE on DNA methylation regulation. It demonstrates that BaP/BPDE exerts a dual-phase regulatory effect on methylation, which is influenced by factors such as the concentration and duration of BaP/BPDE exposure, experimental models and detection methods used in various studies. Acute/high concentration exposure to BaP/BPDE often results in global demethylation of DNA, which is associated with inhibition of DNA methyltransferase 1 (DNMT1) after exposure. At certain specific gene loci (e.g., RAR-β), BPDE can form DNA adducts, recruiting DNMT3 and leading to hypermethylation at specific sites. By integrating these different mechanisms, our goal is to unravel the patterns and regulations of BaP/BPDE-induced DNA methylation changes and provide insights into future precision therapies targeting epigenetics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Mitochondria are essential for various physiological functions in astrocytes in the brain, such as maintaining ion and pH homeostasis, regulating neurotransmission, and modulating neuroinflammation. Mitophagy, a form of autophagy specific to mitochondria, is essential for ensuring mitochondrial quality and function. Benzo[a]pyrene (BaP) accumulates in the brain, and exposure to it is recognized as an environmental risk factor for neurodegenerative diseases. However, while the toxic mechanisms of BaP have been investigated in neurons, their effects on astrocytes-the most prevalent glial cells in the brain-are not clearly understood. Therefore, this study aims to investigate the toxic effects of exposure to BaP on mitochondria in primary astrocytes. Fluorescent probes and genetically encoded indicators were utilized to visualize mitochondrial morphology and physiology, and regulatory factors involved in mitochondrial morphology and mitophagy were assessed. Additionally, the mitochondrial respiration rate was measured in BaP-exposed astrocytes. BaP exposure resulted in mitochondrial enlargement owing to the suppression of mitochondrial fission factors. Furthermore, BaP-exposed astrocytes demonstrated reduced mitophagy and exhibited aberrant mitochondrial function and physiology, such as altered mitochondrial respiration rates, increased mitochondrial superoxide, disrupted mitochondrial membrane potential, and dysregulated mitochondrial Ca 2+ . These findings offer insights into the underlying toxic mechanisms of BaP exposure in neurodegenerative diseases by inducing aberrant mitophagy and mitochondrial dysfunction in astrocytes., Competing Interests: Declaration of Competing Interest The authors report that there are no competing interests to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Extracellular vesicles (EVs) have shown great potential as biomarkers since they reflect the physio-pathological status of the producing cell. In the context of cytotoxicity, it has been found that exposing cells to toxicants leads to changes in protein expression and the cargo of the EVs they produce. Here, we studied large extracellular vesicles (lEVs) derived from human microvascular endothelial cells (HMEC-1) to detect the modifications induced by cell exposure to benzo[a]pyrene (B[a]P). We used a custom CaF 2 -based biochip which allowed hyphenated techniques of investigation: surface plasmon resonance imaging (SPRi) to monitor the adsorption of objects, atomic force microscopy (AFM) to characterise EVs' size and morphology, and Raman spectroscopy to detect molecular modifications. Results obtained on EVs by Raman microscopy and tip-enhanced Raman spectroscopy (TERS) showed significant differences induced by B[a]P in the high wavenumber region of Raman spectra (2800 to 3000 cm -1 ), corresponding mainly to lipid modifications. Two types of spectra were detected in the control sample. A support vector machine (SVM) model was trained on the pre-processed spectral data to differentiate between EVs from cells exposed or not to B[a]P at the spectrum level; this model could achieve a sensitivity of 88% and a specificity of 99.5%. Thus, this experimental setup facilitated the distinction between EVs originating from two cell culture conditions and enabled the discrimination of EV subsets within one cell culture condition., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Polycyclic aromatic hydrocarbons (PAHs) widely present in the environment, but their effect on cerebrovascular development has been rarely reported. In this study, dechorionated zebrafish embryos at 24 hpf were exposed to benzo(a)pyrene (BaP) at 0.5, 5 and 50 nM for 48 h, cerebrovascular density showed a significant reduction in the 5 and 50 nM groups. The expression of aryl hydrocarbon receptor (AhR) was significantly increased. Transcriptomic analysis showed that the pathway of positive regulation of vascular development was down-regulated and the pathway of inflammation response was up-regulated. The transcription of main genes related to vascular development, such as vegf, bmper, cdh5, f3b, itgb1 and prkd1, was down-regulated. Addition of AhR-specific inhibitor CH233191 in the 50 nM BaP group rescued cerebrovascular developmental defects and down-regulation of relative genes, suggesting that BaP-induced cerebrovascular defects was AhR-dependent. The cerebrovascular defects were persistent into adult fish raised in clean water, showing that the relative area of vascular network, the length of vessels per unit area and the number of vascular junctions per unit area were significantly decreased in the 50 nM group. Supplementation of berberine (BBR), a naturally derived medicine from a Chinese medicinal herb, alleviated BaP-induced cerebrovascular defects, accompanied by the restoration of altered expression of AhR and relative genes, which might be due to that BBR promoted BaP elimination via enhancing detoxification enzyme activities, suggesting that BBR could be a potential agent in the prevention of cerebrovascular developmental defects caused by PAHs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Introduction: Heavy metals (HM) and polycyclic aromatic hydrocarbons (PAHs) exposition has been associated with health problems. Therefore, this research evaluated genotoxicity induced in male mice strain CD-1 exposed to benzo[a]anthracene (B[a]A) and benzo[a]pyrene (B[a]P) and their interaction with Fe, Pb, and Al., Methods: Groups of animals were exposed intraperitoneally to HM, PAHs, and mixtures of both. Peripheral blood samples were taken from 0 to 96 h at 24 h intervals; genotoxicity was determined by micronucleus tests and comet assay. Additionally, toxicity and viability were evaluated., Results: HM and PAHs individually were genotoxic. About toxicity, only Al altered polychromatic erythrocytes number and did not change leukocytes viability. Concerning mixtures, Fe + B[a]P, Fe + B[a]A, Pb + B[a]P increased genotoxicity. There were no changes with Pb + B[a]A. Finally, Al mixtures with both PAHs damage was decreased., Conclusions: Exposure to HM and PAH caused genetic damage. Fe, Al, and B[a]A, established a genotoxic potential. Every metal can interact with PAHs in different ways. Also, the micronucleus test and the comet assay demonstrated their high capacity and reliability to determine the genotoxic potential of the compounds evaluated in this work.

Published evidences have suggested that air pollutant benzo(a)pyrene (BaP) may modify the toxicity and adverse effects produced by other toxicants. However, the precise role of short-term exposure to low-dose BaP on acute lung injury (ALI) induced by crystalline silica (CS) and the underlying mechanisms remain to be clarified. To investigate this issue, a mouse co-exposure model was established by intratracheal instillation of 2.5 mg CS and BaP alone or in combination. Our data found that CS exposure resulted in ALI as evidenced by lung histological changes, elevated lactate dehydrogenase activity, increased level of pro-inflammatory markers and enhanced oxidative damage. Although exposure to BaP alone had little effect on the pathological changes of mice lung tissues except for occasionally mild inflammation, it could aggravate the CS-induced ALI in a dose-dependent manner. Bioinformatic analysis of transcriptome sequencing suggested that the expression changes of significantly differentially expressed genes were closely related to the severity of ALI. The joined analysis of STC and WGCNA found that "NOD-like receptor signaling pathway", "toll-like receptor signaling pathway", "TNF signaling pathway", and "NF-kappa B signaling pathway" associated with immune and inflammatory response were the most prominent significant pathways. TLR2/9 and Nod2 might be the key inflammation-related genes that were differentially expressed in the combined lung toxicity induced by CS and BaP exposure. All these findings suggest that co-exposure of CS and low-dose BaP can cause more severe lung inflammation and oxidative damage in mice than exposure alone, which may be useful in the management and prevention of silicosis. The roles of TLR2/9 and Nod2 as candidate targets in the combined toxicity need further exploration., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Wei Li reports financial support was provided by Natural Science Foundation of Jiangsu Province (BK20220664) and Xuzhou Medical University start-up grant for excellent scientist (D2020020). Weiyi Song reports financial support was provided by National Natural Science Foundation of China (82204081), Natural Science Foundation of Jiangsu Province (BK20220665). The authors declare that they have no conflict of interest. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Humans are often exposed to complex mixtures of multiple pollutants rather than a single pollutant. However, the combined toxic effects and the molecular mechanism of PFOS and BaP remain poorly understood. In this study, two typical environmental pollutants, perfluorooctane sulfonate acid (PFOS) and benzo [a]pyrene (BaP), were selected to investigate their combined neurotoxic effects on rat C6 glioma cells at environmentally relevant concentrations. The results showed that coexposure to low-dose PFOS and BaP induced greater toxicity (synergistic effect) than did single exposure. PFOS-BaP coexposure had stronger toxic effects on inducing oxidative stress and promoting early apoptosis. Targeted metabolomics confirmed that increased levels of the neurotransmitters 5-hydroxytryptophan, dopamine, tryptophan and serotonin disturb the phenylalanine, tyrosine and tryptophan biosynthesis pathways. Mechanistically, exposure to a low-dose PFOS-BaP binary mixture induces steroid hormone synthesis disorder through the activation of Cyp1a1 and Hsd17b8 (steroid hormone synthesis genes) and Dhcr24 and Dhcr7 (cholesterol synthesis genes). These findings are useful for comprehensively and systematically elucidating the biological safety of PFOS-BaP and its potential threats to human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon, is known to cause teratogenesis. Environmental exposure of BaP has led to wide public concerns due to their potential risk of reproductive toxicity. However, the exact mechanism is still not clear. We aimed to explore the alterations of oxidative stress and DNA hydroxymethylation during BaP-impaired reproductive function. BALB/c mice were intragastrically administered with different doses of BaP (0.01, 0.1, and 1 mg/kg/day, once a day), while control mice were administered with corn coil. Then, the reproductive function, alterations of oxidative stress, DNA methylation, and DNA hydroxymethylation of testis tissues were evaluated. We found that BaP caused obvious histopathological damages of testis tissues. As for sperm parameters after BaP administration, testis weight and the rate of teratosperm were increased, as well as sperm count and motility were decreased. In mechanism, BaP upregulated HO-1 and MDA levels and downregulated SOD and CAT activity and GSH content in testis tissues, indicating that oxidative stress was induced by BaP. Furthermore, a significant induction of hydroxymethylation and inhibition of methylation were observed in testis tissues after BaP exposure. Collectively, BaP-induced oxidative stress and hydroxymethylation were involved in impairing reproductive function, which may be the mechanism of the male infertility., (© 2024 Wiley Periodicals LLC.)

Exposure to polycyclic aromatic hydrocarbons (PAHs), ubiquitously environmental contaminant, leads to the development of major toxic effects on human health, such as carcinogenic and immunosuppressive alterations reported for the most studied PAH, i.e., benzo(a)pyrene (B(a)P). In order to assess the risk associated with this exposure, it is necessary to have predictive biomarkers. Thus, extracellular vesicles (EVs) and their microRNA (miRNA) contents, have recently been proposed as potentially interesting biomarkers in Toxicology. Our study here explores the use of vesicles secreted and found in blood fluids, and their miRNAs, as biomarkers of exposure to B(a)P alone and within a realistic occupational mixture. We isolated EVs from primary human cultured blood mononuclear cells (PBMCs) and rat plasma after PAH exposure and reported an increased EV production by B(a)P, used either alone or in the mixture, in vitro and in vivo. We then investigated the association of this EV release with the blood concentration of the 7,8,9,10-hydroxy (tetrol)-B(a)P reactive metabolite, in rats. By performing RNA-sequencing (RNA-seq) of miRNAs in PBMC-derived EVs, we analyzed miRNA profiles and demonstrated the regulation of the expression of miR-342-3p upon B(a)P exposure. We then validated B(a)P-induced changes of miR-342-3p expression in vivo in rat plasma-derived EVs. Overall, our study highlights the feasibility of using EVs and their miRNA contents, as biomarkers of PAH exposure and discusses their potential in environmental Toxicology., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Lydie SPARFEL reports financial support was provided by National Agency for Food Environmental and Occupational Health and Safety. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Micro-nano plastics have been reported as important carriers of polycyclic aromatic hydrocarbons (PAHs) for long-distance migration in the environment. However, the combined toxicity from long-term chronic exposure beyond the vehicle-release mechanism remains elusive. In this study, we investigated the synergistic action of Benzo[a]pyrene (BaP) and Polystyrene nanoparticles (PS) in Caenorhabditis elegans (C. elegans) as a combined exposure model with environmental concentrations. We found that the combined exposure to BaP and PS, as opposed to single exposures at low concentrations, significantly shortened the lifespan of C. elegans, leading to the occurrence of multiple senescence phenotypes. Multi-omics data indicated that the combined exposure to BaP and PS is associated with the disruption of glutathione homeostasis. Consequently, the accumulated reactive oxygen species (ROS) cannot be effectively cleared, which is highly correlated with mitochondrial dysfunction. Moreover, the increase in ROS promoted lipid peroxidation in C. elegans and downregulated Ferritin-1 (Ftn-1), resulting in ferroptosis and ultimately accelerating the aging process of C. elegans. Collectively, our study provides a new perspective to explain the long-term compound toxicity caused by BaP and PS at real-world exposure concentrations., Competing Interests: Declaration of competing interest The authors declare no competing financial interests or personal relationship that could potentially influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The global interest in edible insects as sustainable protein sources raises concerns about the bioaccumulation of contaminants, including polycyclic aromatic hydrocarbons (PAHs), to problematic levels. Understanding the accumulation dynamics of PAHs in edible insects is highly relevant due to the widespread sources and toxicological profiles; however, the bioaccumulative potential of PAHs in edible insects is unexplored. This study examined the uptake and elimination dynamics of benzo(a)pyrene (B(a)P), a representative and carcinogenic PAH, in yellow mealworm larvae (YMW, Tenebrio molitor). Larvae were exposed to feeding substrate with varying B(a)P concentrations (0.03, 0.3, and 3 mg kg -1 ), and uptake (21 days in B(a)P-contaminated substrate) and elimination (21 days in B(a)P-free substrate) kinetics were subsequently assessed. The results showed that YMW can eliminate B(a)P, revealing dose-dependent B(a)P bioaccumulation in these insects. Larvae fed on a substrate with 0.03 mg kg -1 accumulated B(a)P over 21 days, presenting values of 0.049 (Standard deviation - 0.011) mg kg -1 and a kinetic-based (BAF kinetic ) of 1.93 g substrate g organism -1 , exceeding the EU regulatory limits for food. However, with a B(a)P half-life (DT 50 ) of 4.19 days in the larvae, an EU legislation safety criterion was met after a 13-day depuration period in clean substrate. Larvae exposed to substrates with 0.3 and 3 mg kg -1 showed B(a)P accumulation, with BAF kinetic values of 3.27 and 2.09 g substrate g organism -1 , respectively, not meeting the current legal standards for food consumption at the end of the exposure to B(a)P. Although the B(a)P half-life values after 35 days were 4.30 and 10.22 days (DT 50s ), the larvae retained B(a)P levels exceeding permitted food safety limits. These findings highlight a significant oversight in regulating PAHs in animal feed and the need for comprehensive safety evaluations of PAH hazards in edible insects for improved PAH feeding guidelines., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Benzo[a]pyrene (BaP) is a ubiquitous environmental pollutant posing various toxicity effects on organisms. Previous studies demonstrated that BaP could induce hepatotoxicity, while the underlying mechanism remains incompletely elucidated. In this study, a comprehensive strategy including network toxicology, transcriptomics and gut microbiomics was applied to investigate the hepatotoxicity and the associated mechanism of BaP exposure in mice. The results showed that BaP induced liver damage, liver oxidative stress and hepatic lipid metabolism disorder. Mechanistically, BaP may disrupt hepatic lipid metabolism through increasing the uptake of free fatty acid (FFA), promoting the synthesis of FA and triglyceride (TG) in the liver and suppressing lipid synthesis in white adipose tissue. Moreover, integrated network toxicology and hepatic transcriptomics revealed that BaP induced hepatotoxicity by acting on several core targets, such as signal transducer and activator of transcription 1 (STAT1), C-X-C motif chemokine ligand 10 (CXCL10) and toll-like receptor 2 (TLR2). Further analysis suggested that BaP inhibited JAK2-STAT3 signaling pathway, as supported by molecular docking and western blot. The 16S rRNA sequencing showed that BaP changed the composition of gut microbiota which may link to the hepatotoxicity based on the correlation analysis. Taken together, this study demonstrated that BaP caused liver injury, hepatic lipid metabolism disorder and gut microbiota dysbiosis, providing novel insights into the hepatotoxic mechanism induced by BaP exposure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objectives: Exposure to benzo[α]pyrene (BaP) increases the incidence and severity of allergic rhinitis (AR), but the underlying mechanisms remain unclear. Thus, we investigated the in vivo effects of BaP exposure on mucus hypersecretion and tissue remodeling in a rat model of AR., Methods: Female Sprague-Dawley rats were randomly divided into 4 groups: a negative control group, a group of healthy rats exposed to BaP, a group of rats with ovalbumin (OVA)-induced AR, and a group of AR model rats exposed to BaP. Nasal symptoms and levels of OVA-specific serum immunoglobulin E (IgE) were measured in each individual rat. Moreover, examination of goblet cell hyperplasia and collagen deposition was carried out with periodic acid-Schiff (PAS) staining and Masson trichrome (MT) staining. Mucin 5AC (MUC5AC) expression was assessed by immunohistochemistry., Results: BaP significantly increased the number of sneezes, the number of nasal rubs and the levels of OVA-specific serum IgE in rats with AR. Statistically significant differences in goblet cell hyperplasia and collagen deposition were observed between the BaP-exposed AR model group and the AR model group. Immunohistochemical results showed that the nasal mucosa of AR model rats displayed markedly elevated MUC5AC expression after BaP exposure., Conclusion: Our data indicate that mucus hypersecretion and the development of nasal remodeling might be pathophysiologic mechanisms underlying increased susceptibility to AR after exposure to BaP., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Advanced materials are materials that have been engineered to exhibit novel or enhanced properties that confer superior performance when compared to conventional materials. Here, we evaluated the impact of Ti 3 C 2 MXenes, a two-dimensional (2D) material, on the adverse effects caused by polycyclic aromatic hydrocarbons. To this end, we studied benzo[a]pyrene denoted here as B[a]P as a model compound. B[a]P was found to adsorb to MXenes as evidenced by UV-Vis spectroscopy. MXenes in the presence or absence of natural organic matter (NOM) were well tolerated by zebrafish embryos. The uptake (ingestion) of MXenes by zebrafish was determined by quantifying the Ti content using inductively coupled plasma mass spectrometry (ICP-MS) while Raman confocal mapping was applied for the label-free identification of MXenes in situ in exposed zebrafish. The body burden of B[a]P was determined by gas chromatography-mass spectrometry (GC-MS). The potential impact of MXenes on B[a]P triggered aryl hydrocarbon receptor (AhR) induction was assessed by evaluating the induction of downstream genes including cyp1a, and results were validated by using the transgenic zebrafish reporter tg(cyp1a-eGFP). The potential impact of MXenes on the genotoxicity caused by B[a]P was also assessed. MXenes were shown to ameliorate AhR induction and DNA damage caused by B[a]P. This was corroborated by using the human colon-derived cell line HT-29. Taken together, MXenes were found to be non-hazardous and alleviated the adverse effects caused by B[a]P in vitro and in vivo., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Benzo [a]pyrene (BaP), a toxic pollutant, increases the incidence and severity of asthma. However, the molecular mechanisms underlying the effects of BaP in asthma remain unclear. In terms of research methods, we used BaP to intervene in the animal model of asthma and the human bronchial epithelial (16HBE) cells, and the involved mechanisms were found from the injury, inflammation, and airway epithelial to mesenchymal transition (EMT) in asthma. We also constructed small interfering RNAs and overexpression plasmids to knockdown/overexpress IL-6R and FOXA2 in 16HBE cells and a serotype 9 adeno-associated viral vector for lung tissue overexpression of FOXA2 in mice to determine the mechanism of action of BaP-exacerbated asthma airway EMT. We observed that BaP aggravated inflammatory cell infiltration into the lungs, reduced the Penh value, increased collagen fibres in the lung tissue, and increased serum IgE levels in asthmatic mice. After BaP intervention, the expression of FOXA2 in the lung tissue of asthmatic mice decreased, the production and secretion of IL-6 were stimulated, and STAT3 phosphorylation and nuclear translocation increased, leading to changes in EMT markers. However, EMT decreased after increasing FOXA2 expression and decreasing that of IL-6R and was further enhanced after low FOXA2 expression. Our results revealed that BaP exacerbated airway epithelial cell injury and interfered with FOXA2, activating the IL-6/IL-6R/STAT3 signaling pathway to promote airway EMT in asthma. These findings provide toxicological evidence for the mechanism underlying the contribution of BaP to the increased incidence of asthma and its exacerbations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Recently, the abundance of environmental microplastics (MPs) has become a global paramount concern. Besides the danger of MPs for biota due to their tiny size, these minute particles may act as vectors of other pollutants. This study focused on evaluating the toxicity of environmentally relevant concentrations of MPs (10 and 50 mg/kg sediment) and benzo[a]pyrene (B[a]P, 1 µg/kg sediment), alone and in mixture, for 3 and 7 days in marine polychaete Hediste diversicolor, selected as a benthic bioindicator model. The exposure period was sufficient to confirm the bioaccumulation of both contaminants in seaworms, as well as the potential capacity of plastic particles to adsorb and vehiculate the B[a]P. Interestingly, increase of acidic mucus production was observed in seaworm tissues, indicative of a defense response. The activation of oxidative system pathways was demonstrated as a strategy to prevent lipid peroxidation. Furthermore, the comprehensive Nuclear Magnetic Resonance (NMR)-based metabolomics revealed significant disorders in amino acids metabolism, osmoregulatory process, energetic components, and oxidative stress related elements. Overall, these findings proved the possible synergic harmful effect of MPs and B[a]P even in small concentrations, which increases the concern about their long-term presence in marine ecosystems, and consequently their transfer and repercussions on marine fauna., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Utilizing molecular dynamics and free energy perturbation, we examine the relative binding affinity of several covalent polycyclic aromatic hydrocarbon - DNA (PAH-DNA) adducts at the central adenine of NRAS codon-61, a mutational hotspot implicated in cancer risk. Several PAHs classified by the International Agency for Research on Cancer as probable, possible, or unclassifiable as to carcinogenicity are found to have greater binding affinity than the known carcinogen, benzo[a]pyrene (B[a]P). van der Waals interactions between the intercalated PAH and neighboring nucleobases, and minimal disruption of the DNA duplex drive increases in binding affinity. PAH-DNA adducts may be repaired by global genomic nucleotide excision repair (GG-NER), hence we also compute relative free energies of complexation of PAH-DNA adducts with RAD4-RAD23 (the yeast ortholog of human XPC-RAD23) which constitutes the recognition step in GG-NER. PAH-DNA adducts exhibiting the greatest DNA binding affinity also exhibit the least RAD4-RAD23 complexation affinity and are thus predicted to resist the GG-NER machinery, contributing to their genotoxic potential. In particular, the fjord region PAHs dibenzo[a,l]pyrene, benzo[g]chrysene, and benzo[c]phenanthrene are found to have greater binding affinity while having weaker RAD4-RAD23 complexation affinity than their respective bay region analogs B[a]P, chrysene, and phenanthrene. We also find that the bay region PAHs dibenzo[a,j]anthracene, dibenzo[a,c]anthracene, and dibenzo[a,h]anthracene exhibit greater binding affinity and weaker RAD4-RAD23 complexation affinity than B[a]P. Thus, the study of PAH genotoxicity likely needs to be substantially broadened, with implications for public policy and the health sciences. This approach can be broadly applied to assess factors contributing to the genotoxicity of other unclassified compounds., Competing Interests: Competing interests statement:NSF grant CHE-2203366.

To address two current issues in evaluating the toxicity of microplastics (MPs) namely, conflicting results due to species specificity and the ecological irrelevance of laboratory data, this study conducted a 10-day exposure experiment using a microalgal community comprising three symbiotic species. The experiment involved virgin and Benzo[a]pyrene-spiked micron-scale fibers and fragments made of polyethylene terephthalate (PET) and polypropylene (PP). The results showed that, from a physiological perspective, environmentally relevant concentrations of micron-scale MPs decreased saccharide accumulation in microalgal cells, as confirmed by ultrastructural observations. MPs may increase cellular energy consumption by obstructing cellular motility, interfering with nutrient uptake, and causing sustained oxidative stress. Additionally, MPs and adsorbed B[a]P induced DNA damage in microalgae, potentially further disrupting cellular energy metabolism. Ecologically, MPs altered the species abundance in microalgal communities, suggesting they could weaken the ecological functions of these communities as producers and affect ecosystem diversity and stability. This study marks a significant advancement from traditional single-species toxicity experiments to community-level assessments, providing essential insights for ecological risk assessment of microplastics and guiding future mechanistic studies utilizing multi-omics analysis., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Shuo Cheng reports financial support was provided by Japan Society for the Promotion of Science. Shuo Cheng reports a relationship with East China Normal University, Shanghai, China that includes: paid expert testimony. We with this apply for recusal. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Benzo[a]pyrene (BaP) is a contaminant that is generated in the environment through processes such as smoke, incomplete combustion of fossil fuels, vehicle exhaust emissions, entry into the body is through inhalation, and consumption of contaminated food. It is an omnipresent environmental pollutant with unavoidable exposure. BaP metabolites are observed in the male reproductive system, especially in the testes and epididymis of animals, and are responsible for reduced testicular and epididymal function. The protective effect of atorvastatin (ATV) on testicular damage was investigated previously. The aim of the present study was to investigate the protective effect of ATV on testicular toxicity induced by benzo[a]pyrene (BaP) during pregnancy in Wistar rats. This experimental laboratory study involved 40 adult rats, divided into seven groups and maintained under standard environmental conditions. The groups received different diets [control, corn oil, ATV (10 mg/kg), BaP (10 and 20 mg/kg), and ATV + BaP (10 and 20 mg/kg)] at gestation Days 7-16, orally. Male offspring were examined 10 weeks after birth. Testis and serum samples were collected, and testosterone level, malondialdehyde (MDA), and glutathione (GSH) were measured. Histological and immunohistochemical assays were performed under a light microscope. Statistical analysis was conducted using SPSS, with analysis of variance and Tukey tests to assess significant differences between groups. ATV significantly reduced MDA, a marker of lipid peroxidation and oxidative stress in rat testes following BaP administration. Treatment with ATV at doses of 10 mg/kg increased GSH levels, correcting disruptions in the antioxidant system caused by BaP. Testosterone concentration in rats treated with ATV and BaP substantially prevented the decrease induced by BaP. Histomorphometry revealed that ATV significantly prevented the detrimental effects of BaP on the thickness of spermatogenic epithelium and the diameter of seminiferous tubules. Under ATV treatment, testicular tissue histopathology improved, and spermatogenesis returned to a almost back to normal state. Caspase-3 expression decreased, and apoptosis activity in testicular tissue improved under ATV treatment, indicating a positive effect of ATV in reducing apoptotic damage caused by BaP. In conclusion, exposure to BaP can induce oxidative stress-related damage to testicular tissue, as evidenced by an increase in MDA levels, which ATV treatment can mitigate. Additionally, ATV enhances intracellular antioxidant GSH and protects the testes against BaP-induced damage while increasing testosterone levels, which are reduced due to exposure to BaP., (© 2024 Wiley Periodicals LLC.)

Benzo[a]pyrene (BaP) is associated with the development of lung cancer, but the underlying mechanism has not been completely clarified. Here, we used 10 μM BaP to induce malignant transformation of human bronchial epithelial BEAS-2B cells, named BEAS-2B-T. Results indicated that BaP (6.25, 12.5 and 25 μM) treatment significantly promoted the migration and invasion of BEAS-2B-T cells. Meanwhile, BaP exposure inhibited ferroptosis in BEAS-2B-T, ferroptosis-related indexes Fe 2+ , malondialdehyde (MDA), lipid peroxidation (LPO) and reactive oxygen species (ROS) decreased significantly. The protein level of ferroptosis-related molecule transferrin receptor (TFRC) decreased significantly, while solute carrier family 7 membrane 11 (SLC7A11), ferritin heavy chain 1 (FTH1) and glutathione peroxidase 4 (GPX4) increased significantly. The intervention of ferroptosis dramatically effected the migration and invasion of BEAS-2B-T induced by BaP. Furthermore, the expression of YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) was markedly increased after BaP exposure. YTHDF1 knockdown inhibited BEAS-2B-T migration and invasion by promoting ferroptosis. In the meantime, the contents of Fe 2+ , MDA, LPO and ROS increased significantly, TFRC was markedly increased, and SLC7A11, FTH1, and GPX4 were markedly decreased. Moreover, overexpression of YTHDF1 promoted BEAS-2B-T migration and invasion by inhibiting ferroptosis. Importantly, knockdown of YTHDF1 promoted ferroptosis and reduced BEAS-2B-T migration and invasion during BaP exposure, and overexpression of YTHDF1 increased migration and invasion of BEAS-2B-T by inhibiting ferroptosis during BaP exposure. RNA immunoprecipitation assays indicated that the binding of YTHDF1 to SLC7A11 and FTH1 markedly increased after YTHDF1 overexpression. Therefore, we concluded that BaP promotes the malignant progression of BEAS-2B-T cells through YTHDF1 upregulating SLC7A11 and FTH1 to inhibit ferroptosis. This study reveals new epigenetic and ferroptosis markers for preventing and treating lung cancer induced by environmental carcinogens., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Benzo[a]pyrene (BaP), a representative five-membered polycyclic aromatic hydrocarbon, has been extensively studied as a pollutant for decades. Despite this, sex-specific responses to BaP exposure remain poorly understood. This study employed a life-cycle exposure approach to investigate the effects of prolonged BaP exposure on marine medaka (Oryzias melastigma), highlighting sex-specific responses. After a 90-day exposure period, significant variations in biometric measurements and oxidative stress markers were observed between male and female fish. BaP exposure resulted in weak detoxification defense in males, while females exhibited an opposite response. Transcriptomic analysis revealed 13 significantly enriched pathways in males and 11 in females, with varying numbers of differentially expressed genes between the sexes, highlighting distinct biological responses. Host resistance assay showed higher mortality rates among BaP-exposed males, and suppressed immune gene expressions and lysozyme activity, while females demonstrated enhanced immune genes and lysozyme activity post-challenge, indicating a more resilient defense response. Furthermore, after a one-month depuration period following BaP exposure, male medaka demonstrated slower recoverability compared to females. These findings underscore sex-specific effects of BaP exposure on fish, with females displaying stronger resilience. Understanding these distinctions are crucial for accurately assessing the impact of environmental pollutants on the aquatic population and ecosystem maintenance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Food emulsifiers like glycerol monostearate (G) and Tween 80 (TW) are commonly used to help formation and maintain stability of emulsions. However, certain food contaminants and emulsifiers often co-occur in the same food item due to food culture and cooking methods. For this reason, the present study investigated interaction of toxic effect of emulsifiers (G and TW) and process contaminants (acrylamide (AA) and benzo [a]pyrene (BAP)) on zebrafish. Adult zebrafish were exposed to emulsifiers, food contaminants, or the combination through diet for 2 h and 7 days. Oxidative stress and inflammation caused by food contaminants were increased when food emulsifiers were present. These combined treatments also induced more severe morphological changes than the contaminant alone treatments. In the gut, disruption of villi structure and increased number of goblet cells was observed and in the liver there were increased lipid deposition, infiltration of immune cells, glycogen depletion and focal necrosis. Increased accumulation of AA and BAP in the liver and gut were detected after addition of emulsifiers, suggesting that emulsifiers can enhance absorption of diet-borne contaminants. Our results showed food emulsifiers and contaminants can interact synergistically and increase risk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microplastics (MPs) and polycyclic aromatic hydrocarbons (PAHs) are priority contaminants of marine environments. However, their combined toxic effects on aquatic organisms are still largely unclear. In this study, the toxicological effects of microplastics (MPs) and Benzo[a]pyrene (BaP), a representative PAH, on Asian sea bass Lates calcarifer was investigated. Juvenile Asian sea bass were exposed for 56 days to polyethylene MPs (0.1 and 1 mg/L) and BaP (20 and 80 μg/L) as single or combined environmental stressors. The effects of MPs and BaP exposure on fish were evaluated considering several biological indices such as growth and condition indices, the oxidative stress response in the liver, and the expression levels of genes related to the stress, immunomodulation, detoxification, and apoptosis. Exposure to MPs and BaP in single or combined experiments significantly (P < 0.05) decreased fish growth, and altered body protein content and food conversion ratio (FCR), but greater magnitudes of changes was observed in the combined experimental group of BaP80 + MP1. The activities of liver antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) decreased; meanwhile, malondialdehyde (MDA) activity was dramatically enhanced (P < 0.05). The combined groups with higher concentrations (BaP80+ MP1) caused more severe alterations in enzyme levels compared to the single exposure groups and lower concentrations. MDA was the most affected among the studied enzymes. The expression levels of functional genes involved in stress response (GPX, HSP70, HSP90), pro-inflammation (LYZ, IL-1β, IL-8, and TNF-α), and detoxification (CYP1A) displayed significant alterations as the result of exposure to MPs and BaP single and in combination. The transcription levels of functional genes were more affected in fish exposed to BaP at 80 ng/mL when combined with MPs at 1 mg/mL. Additionally, MPs and BaP heightened the expression of apoptotic-related genes (p53 and caspase-3) on day 7 of exposure in a dose-dependent synergetic manner (P < 0.05). The results of this study demonstrate that exposure to MPs and BaP alone results in significant alterations in fish growth and condition factors, and could activate the stress response, stimulate the anti-oxidative defense system, immune transcriptomic response, and apoptosis in Asian sea bass; however, MPs can enhance the adverse effects of BaP on biological markers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: Benzo[a]pyrene (B[a]P) is a carcinogenic polycyclic aromatic hydrocarbon that poses significant risks to human health. B[a]P influences cellular processes via intricate interactions; however, a comprehensive understanding of B[a]P's effects on the transcriptome remains elusive. This study aimed to conduct a comprehensive analysis focused on identifying relevant genes and signaling pathways affected by B[a]P exposure and their impact on human gene expression., Methods: We searched the Gene Expression Omnibus database and identified four studies involving B[a]P exposure in human cells (T lymphocytes, hepatocellular carcinoma cells, and C3A cells). We utilized two approaches for differential expression analysis: the LIMMA package and linear regression. A meta-analysis was utilized to combine log fold changes (FC) and p-values from the identified studies using a random effects model. We identified significant genes at a Bonferroni-adjusted significance level of 0.05 and determined overlapping genes across datasets. Pathway enrichment analysis elucidated key cellular processes modulated by B[a]P exposure., Results: The meta-analysis revealed significant upregulation of CYP1B1 (log FC = 1.15, 95% CI: 0.51-1.79, P < 0.05, I 2  = 82%) and ASB2 (log FC = 0.44, 95% CI: 0.20-0.67, P < 0.05, I 2  = 40%) in response to B[a]P exposure. Pathway analyses identified 26 significantly regulated pathways, with the top including Aryl Hydrocarbon Receptor Signaling (P = 0.00214) and Xenobiotic Metabolism Signaling (P = 0.00550). Key genes CYP1A1, CYP1B1, and CDKN1A were implicated in multiple pathways, highlighting their roles in xenobiotic metabolism, oxidative stress response, and cell cycle regulation., Conclusion: The results provided insights into the mechanisms of B[a]P toxicity, highlighting CYP1B1's key role in B[a]P bioactivation. The findings underscored the complexity of B[a]P's mechanisms of action and their potential implications for human health. The identified genes and pathways provided a foundation for further exploration and enhanced our understanding of the multifaceted biological activities associated with B[a]P exposure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Benzo(a)pyrene (BaP) or benzo (a) pyrene 7,8-dihydrodiol-9,10-epoxide (BPDE) exposure causes trophoblast cell dysfunctions and induces miscarriage, which is generally epigenetically regulated. Homologous recombination (HR) repair of DNA double strand break (DSB) plays a crucial role in maintenance of genetic stability and cell normal functions. However, whether BaP/BPDE might suppress HR repair in human trophoblast cells to induce miscarriage, as well as its epigenetic regulatory mechanism, is largely unclear. In this study, we find that BaP/BPDE suppresses HR repair of DSB in trophoblast cells and eventually induces miscarriage by up-regulating lnc-HZ08. In mechanism, lnc-HZ08 (1) down-regulates the expression levels of FOXA1 (forkhead box A1) and thus suppresses FOXA1-mediated mRNA transcription of BRCA1 (Breast cancer susceptibility gene 1) and CtIP (CtBP-interacting protein), (2) impairs BRCA1 and CtIP protein interactions by competitive binding with CtIP through lnc-HZ08-1 fragment, and also (3) suppresses BRCA1-mediated CtIP ubiquitination without affecting CtIP stability, three of which eventually suppress HR repair in human trophoblast cells. Supplement with murine Ctip could efficiently restore (i.e. increase) HR repair and alleviate miscarriage in BaP-exposed mouse model. Collectively, this study not only reveals the association and causality among BaP/BPDE exposure, the defective HR repair, and miscarriage, but also discovers novel mechanism in lnc-HZ08-regulated BRCA1/CtIP-mediated HR repair, bridging epigenetic regulation and genetic instability and also providing an efficient approach for treatment against BaP/BPDE-induced unexplained miscarriage., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Ultraviolet (UV) exposure and atmospheric pollution are both independently implicated in skin diseases such as cancer and premature aging. UVA wavelengths, which penetrate in the deep layers of the skin dermis, exert their toxicity mainly through chromophore photosensitization reactions. Benzo[a]pyrene (BaP), the most abundant polycyclic aromatic hydrocarbon originating from the incomplete combustion of organic matter, could act as a chromophore and absorb UVA. We and other groups have previously shown that BaP and UVA synergize their toxicity in skin cells, which leads to important oxidation. Even if mitochondria alterations have been related to premature skin aging and other skin disorders, no studies have focused on the synergy between UV exposure and pollution on mitochondria. Our study aims to investigate the combined effect of UVA and BaP specifically on mitochondria in order to assess the effect on mitochondrial membranes and the consequences on mitochondrial activity. We show that BaP has a strong affinity for mitochondria and that this affinity leads to an important induction of lipid peroxidation and membrane disruption when exposed to UVA. Co-exposure to UVA and BaP synergizes their toxicity to negatively impact mitochondrial membrane potential, mitochondrial metabolism and the mitochondrial network. Altogether, our results highlight the implication of mitochondria in the synergistic toxicity of pollution and UV exposure and the potential of this toxicity on skin integrity.

Chemicals often require metabolic activation to become genotoxic. Established test guidelines recommend the use of the rat liver S9 fraction or microsomes to introduce metabolic competence to in vitro cell-based bioassays, but the use of animal-derived components in cell culture raises ethical concerns and may lead to quality issues and reproducibility problems. The aim of the present study was to compare the metabolic activation of cyclophosphamide (CPA) and benzo[ a ]pyrene (BaP) by induced rat liver microsomes and an abiotic cytochrome P450 (CYP) enzyme based on a biomimetic porphyrine catalyst. For the detection of genotoxic effects, the chemicals were tested in a reporter gene assay targeting the activation of the cellular tumor protein p53. Both chemicals were metabolized by the abiotic CYP enzyme and the microsomes. CPA showed no activation of p53 and low cytotoxicity without metabolic activation, but strong activation of p53 and increased cytotoxicity upon incubation with liver microsomes or abiotic CYP enzyme. The effect concentration causing a 1.5-fold induction of p53 activation was very similar with both metabolization systems (within a factor of 1.5), indicating that genotoxic metabolites were formed at comparable concentrations. BaP also showed low cytotoxicity and no p53 activation without metabolic activation. The activation of p53 was detected for BaP upon incubation with active and inactive microsomes at similar concentrations, indicating experimental artifacts caused by the microsomes or NADPH. The activation of BaP with the abiotic CYP enzyme increased the cytotoxicity of BaP by a factor of 8, but no activation of p53 was detected. The results indicate that abiotic CYP enzymes may present an alternative to rat liver S9 fraction or microsomes for the metabolic activation of test chemicals, which are completely free of animal-derived components. However, an amendment of existing test guidelines would require testing of more chemicals and genotoxicity end points.

Benzo[a]pyrene (B[a]P) is known to inhibit neurodifferentiation and induce neurodegeneration. Agarwood or Aquilaria crassna (AC), a plant with health-promoting properties, may counteract the neurotoxic effects of B[a]P by promoting neuronal growth and survival. This study investigated the protective effect of AC leaf ethanolic extract (ACEE) on the B[a]P-induced impairment of neuronal differentiation. A transcriptomic analysis identified the canonical pathway, the biological network, and the differentially expressed genes (DEGs) that are changed in response to neuronal differentiation and neurogenesis. Several genes, including CXCR4 , ENPP2 , GAP43 , GFRA2 , NELL2 , NFASC , NSG2 , NGB , BASP1 , and NEUROD1 , in B[a]P-treated SH-SY5Y cells were up-regulated after treatment with ACEE. Notably, a Western blot analysis further confirmed that ACEE increased the protein levels of GAP43 and neuroglobin. B[a]P treatment led to decreased phosphorylation of Akt and increased phosphorylation of ERK in SH-SY5Y cells; however, ACEE was able to reverse these effects. Clionasterol and lupenone were identified in ACEE. Molecular docking showed that these two phytochemicals had significant interactions with CXCR4, GDNF family receptor alpha (GFRA), and retinoid X receptors (RXRs). In conclusion, ACEE may be a potential alternative medicine for the prevention of impaired neuronal differentiation and neurodegenerative diseases.

The skin is a direct target of the air pollutant benzo[a]pyrene (BaP). While its carcinogenic qualities are well-studied, the immunotoxicity of BaP after dermal exposure is less understood. This study examines the immunomodulatory effects of a 10-day epicutaneous BaP application, in environmentally/occupationally relevant doses, by analyzing ex vivo skin immune response (skin explant, epidermal cells and draining lymph node/DLN cell activity), alongside the skin's reaction to sensitization with experimental hapten dinitrochlorobenzene (DNCB). The results show that BaP application disrupts the structure of the epidermal layer and promotes immune cell infiltration in the dermis. BaP exposure led to oxidative stress in epidermal cells, characterized by decreased reduced glutathione and increased AHR and Cyp1A1 expression. Production and gene expression of proinflammatory cytokines (TNF, IL-1β) by epidermal cells decreased, while IL-10 response increased. Decreased spontaneous production of IFN-γ and IL-17, along with unchanged IL-10, was observed in DLC cells, whereas ConA-stimulated production of these cytokines was elevated. Local immunosuppression caused by BaP application seems to reduce the skin's response to an additional stimulus, evidenced by decreased effector activity of DLN cells three days after sensitization with DNCB. These findings provide new insight into the immunomodulatory effects and health risks associated with skin exposure to BaP.

Polycyclic aromatic hydrocarbons (PAHs), notably benzo[a]pyrene (BaP), are environmental contaminants with multiple adverse ecological implications. Numerous studies have suggested the use of BaP biodegradation using various bacterial strains to remove BaP from the environment. This study investigates the BaP biodegradation capability of Pigmentiphaga kullae strain KIT-003, isolated from the Nak-dong River (South Korea) under specific environmental conditions. The optimum conditions of biodegradation were found to be pH 7.0, 35°C, and a salinity of 0 %. GC-MS analysis suggested alternative pathways by which KIT-003 produced catechol from BaP through several intermediate metabolites, including 4-formylchrysene-5-carboxylic acid, 5,6-dihydro-5,6-dihydroxychrysene-5-carboxylic acid (isomer: 3,4-dihydro-3,4-dihydroxychrysene-4-carboxylic acid), naphthalene-1,2-dicarboxylic acid, and 2-hydroxy-1-naphthoic acid. Proteomic profiles indicated upregulation of enzymes associated with aromatic compound degradation, such as nahAc and nahB, and of those integral to the tricarboxylic acid cycle, reflecting the strain's adaptability to and degradation of BaP. Lipidomic analysis of KIT-003 demonstrated that BaP exposure induced an accumulation of glycerolipids such as diacylglycerol and triacylglycerol, indicating their crucial role in bacterial adaptation mechanisms under BaP stress. This study provides significant scientific knowledge regarding the intricate mechanisms involved in BaP degradation by microorganisms., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Polycyclic aromatic hydrocarbons (PAHs) accumulate and integrate into aquatic environments, raising concerns about the well-being and safety of aquatic ecosystems. Benzo[a]pyrene (BaP), a persistent PAH commonly detected in the environment, has been extensively studied. However, the broader multifaceted toxicity potential of BaP on the early life stages of marine fish during chronic exposure to environmentally relevant concentrations needs further exploration. To fill these knowledge gaps, this study assessed the in vivo biotoxicity of BaP (1, 4, and 8 μg/L) in marine medaka (Oryzias melastigma) during early development over a 30-day exposure period. The investigation included morphological, biochemical, and molecular-level analyses to capture the broader potential of BaP toxicity. Morphological analyses showed that exposure to BaP resulted in skeletal curvatures, heart anomalies, growth retardation, elevated mortality, delayed and reduced hatching rates. Biochemical analyses revealed that BaP exposure not only created oxidative stress but also disrupted the activities of antioxidant enzymes. This disturbance in redox balance was further explored by molecular level investigation. The transcriptional profiles revealed impaired oxidative phosphorylation (OXPHOS) and tricarboxylic acid (TCA) cycle pathways, which potentially inhibited the oxidative respiratory chain in fish following exposure to BaP, and reduced the production of adenosine triphosphate (ATP) and succinate dehydrogenase (SDH). Furthermore, this investigation indicated a potential connection to apoptosis, as demonstrated by fluorescence microscopy and histological analyses, and supported by an increase in the expression levels of related genes via real-time quantitative PCR. This study enhances our understanding of the molecular-level impacts of BaP's multifaceted toxicity in the early life stages of marine medaka, and the associated risks., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon compound that is generated during combustion processes, and is present in various substances such as foods, tobacco smoke, and burning emissions. BaP is extensively acknowledged as a highly carcinogenic substance to induce multiple forms of cancer, such as lung cancer, skin cancer, and stomach cancer. Recently it is shown to adversely affect the reproductive system. Nevertheless, the potential toxicity of BaP on oocyte quality remains unclear. In this study, we established a BaP exposure model via mouse oral gavage and found that BaP exposure resulted in a notable decrease in the ovarian weight, number of GV oocytes in ovarian, and oocyte maturation competence. BaP exposure caused ribosomal dysfunction, characterized by a decrease in the expression of RPS3 and HPG in oocytes. BaP exposure also caused abnormal distribution of the endoplasmic reticulum (ER) and induced ER stress, as indicated by increased expression of GRP78. Besides, the Golgi apparatus exhibited an abnormal localization pattern, which was confirmed by the GM130 localization. Disruption of vesicle transport processes was observed by the abnormal expression and localization of Rab10. Additionally, an enhanced lysosome and LC3 fluorescence intensity indicated the occurrence of protein degradation in oocytes. In summary, our results suggested that BaP exposure disrupted the distribution and functioning of organelles, consequently affecting the developmental competence of mouse oocytes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Prenatal exposure to Benzo[a]pyrene (BaP) has been suggested to increase the risk of adverse pregnancy outcomes. However, the role of placental apoptosis on BaP reproductive toxicity is poorly understood. We conducted a maternal animal model of C57BL/6 wild-type (WT) and transformation-related protein 53 (Trp53) heterozygous knockout (p53KO) mice, as well as a nested case-control study involving 83 women with PB and 82 term birth from a birth cohort on prenatal exposure to BaP and preterm birth (PB). Pregnant WT and p53KO mice were randomly allocated to BaP treatment and control groups, intraperitoneally injected of low (7.8 mg/kg), medium (35 mg/kg), and high (78 mg/kg) doses of 3,4-BaP per day and equal volume of vegetable oil, from gestational day 10.5 until delivery. Results show that high-dose BaP treatment increased the incidence of preterm birth in WT mice. The number of fetal deaths and resorptions increased with increasing doses of BaP exposure in mice. Notably, significant reductions in maternal and birth weights, increases in placental weights, and decrease in the number of livebirths were observed in higher-dose BaP groups in dose-dependent manner. We additionally observed elevated p53-mediated placental apoptosis in higher BaP exposure groups, with altered expression levels of p53 and Bax/Bcl-2. In case-control study, the expression level of MMP2 was increased among women with high BaP exposure and associated with the increased risk of all PB and moderate PB. Our study provides the first evidence of BaP-induced reproductive toxicity and its adverse effects on maternal-fetal outcomes in both animal and population studies., (© 2024. The Author(s).)