The possible DNA damage induced by environmental organic compounds: The case of Nonylphenol

From challenge to opportunity: Revolutionizing the monitoring of emerging contaminants in water with advanced sensors

Emerging contaminants in water represent long-term and unpredictable threats to both environmental and human health due to their persistence and bioaccumulation. Current research predominantly focuses on their removal rather than sustained monitoring. This review comprehensively investigates advanced sensor technologies for detecting these contaminants in water, critically evaluating biosensors, optical sensors, electrochemical sensors, and nanomaterial sensors. Elucidating the operational principles, performance metrics such as detection thresholds, and the pros and cons of their practical applications, the review addresses a significant research gap in environmental monitoring. Moreover, it enhances understanding of sensor effectiveness, which in turn guides researchers in selecting the right sensor types for various environmental scenarios. Furthermore, by emphasizing the integration of nanotechnology and the standardization of evaluation protocols, it promotes the development of robust, deployable sensing solutions. Ultimately, this leads to the proposal of a strategic framework aimed at significantly improving the detection capabilities of emerging contaminants and supporting the preservation of environmental health.

Enhanced kidney damage induced by increasing nonylphenol doses: impact on autophagy-related proteins and proinflammatory cytokines in rats

Nonylphenol (NP) is an organic pollutant and endocrine disruptor chemical that has harmful effects on the environment and living organisms. This study looked at whether kidney tissues subjected to increasing doses of nonylphenol generated alterations in histopathologic, pro-inflammatory, and autophagic markers. Fifty rats were divided into five groups of ten each: group I: healthy group, II: control (corn oil), group III: 25 μl/kg NP, group IV: 50 μl/kg NP, group V: 75 μl/kg NP. The kidney tissue samples were obtained for histopathological, immunohistochemical, and biochemical analyses. The histological deteriorations observed in all NP groups included tubular epithelial cell degeneration, inflammation areas, and hemorrhage. The immunohistochemical investigations showed that NP significantly elevated the autophagy markers (Beclin-1, LC3A/B, p62), pro-inflammatory cytokines (TNF-α, IL-6), HIF-1α, and eNOS in group III, IV and V compared with group I and II. The biochemical analysis also revealed that pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) increased in correlation with the NP doses, but only IL-1β reached statistical significance in NP treated rats kidney tissue. The biochemical findings have been confirmed by the histological studies. The damage to renal tissue caused by NP exposure may worsen it by increasing inflammatory and autophagic markers.

Co-administration of thymol and sulfoxaflor impedes the expression of reproductive toxicity in male rats

This study investigated the capability of a co-delivery system of thymol (THY) and sulfoxaflor that can serve to minimize the development of epididymal and testicular injury arise from SFX exposures alone. Forty-eight adult male rats were orally treated by gavage for 28 consecutive days. The rats were divided into six groups comprising control, THY alone (30 mg/kg), low SFX alone (79.4 mg/kg), high SFX alone (205 mg/kg) and co-exposure groups. After euthanasia, the rats epididymal and testicular damage and antioxidant status markers, myeloperoxidase (MPO) activity, levels of nitric oxide, total antioxidant capacity (TAC), total oxidative stress (TOS) and lipid peroxidation (LPO) were analyzed. Levels of tumor necrosis factor alpha (TNF-α), interleukin-1 b (IL-1β) and caspase-3 activity were assessed using ELISA kits. The results revealed that SFX exposure caused a significant (p < 0.05) decrease in the body weight, sperm functional parameters, serum testosterone level with widespread histological abnormalities in a dose-dependent manner. Increased relative organ weights, serum levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were observed in low SFX-treated rats. Similarly, the epididymal and testicular myeloperoxidase activity, malondialdehyde (MDA), reactive oxygen species (RONS), tumor necrosis-α, interleukin-1β levels and caspase-3 activity were significant (p < 0.05) increased and a significant (p < 0.05) reduction in antioxidant enzyme activities and reduced glutathione (GSH) were revealed in SFX-treated rats. However, co-treatment of THY with SFX prevented SFX-induced epididymal and testicular toxicities. Thus, thymol protected against potential epididymis and testes alterations elicited by oxido-inflammatory mediators and up regulated antioxidant status.

Exploring the impact of nonylphenol exposure on Litopenaeus vannamei at the histological and molecular levels

Nonylphenol (NP) is one of the common pollutants in the environment that have toxic effects on aquatic animals. Nevertheless, little is known about the possible toxicity mechanism of NP on the hepatopancreas of Litopenaeus vannamei. In the present study, the detrimental effects of NP on the hepatopancreas of the L. vannamei were explored at the histological and transcriptomic levels. The findings indicated that after NP exposed for 3, 12, and 48 h, the hepatopancreas histology was changed significantly. Transcriptomic analysis showed that a total of 4302, 3651, and 4830 differentially expressed genes (DEGs) were identified at 3, 12, and 48 h following NP exposure. All these DEGs were classified into 12 clusters according to the expression patterns at different time points. GO and KEGG enrichment analyses of DEGs were also performed, immunological, metabolic, and inflammatory related pathways, including arachidonic acid metabolism (ko00590), the PPAR signaling pathway (ko03320), and the regulation of TRP channels by inflammatory mediators (ko04750) were significantly enriched. Six DEGs were selected for validation by quantitative real-time PCR (qRT-PCR) and the results confirmed the reliability of transcriptome data. All results indicated that NP is toxic to L. vannamei by damaging the histopathological structure and disrupting the biological function. The findings would provide a theoretical framework for lowering or limiting the detrimental impacts of NP on aquaculture and help us to further study the molecular toxicity of NP in crustaceans.

Nonylphenol and its derivatives: Environmental distribution, treatment strategy, management and future perspectives

In recent years, emerging pollutants, including nonylphenol (NP) and nonylphenol ethoxylate (NPE), have become a prominent topic. These substances are also classified as persistent organic pollutants. NP significantly affects the hormone secretion of organisms and exhibits neurotoxicity, which can affect the human hippocampus. Therefore, various countries are paying increased attention to NP regulation. NPEs are precursors of NPs and are widely used in the manufacture of various detergents and lubricants. NPEs can easily decompose into NPs, which possess strong biological and environmental toxicity. This review primarily addresses the distribution, toxicity mechanisms and performance, degradation technologies, management policies, and green alternative reagents of NPs and NPEs. Traditional treatment measures have been unable to completely remove NP from wastewater. With the progressively tightening management and regulatory policies, identifying proficient and convenient treatment methods and a sustainable substitute reagent with comparable product effectiveness is crucial.

Environmentally Relevant Concentrations of the Insecticide Fipronil Modulated Molecular Response in Chironomus riparius

Pesticides employed worldwide for crop protection easily reach aquatic systems, which act as the main reservoirs, and become a risk factor for aquatic fauna. Fipronil is a broad-spectrum insecticide acting on the insect nervous system; however, other effects and systems unrelated to this mechanism could be affected in non-target organisms. Thus, the present study aimed to assess the impact of fipronil on the suborganismal response (gene expression and enzymatic activity) of Chironomus riparius larvae as a model organism in ecotoxicology. To this end, short-term toxicity tests were carried out with fourth-instar larvae exposed to 0.001, 0.01, and 0.1 µg L-1 of fipronil for 24 and 96 h. Messenger RNA levels of 42 genes related to diverse metabolic pathways were analyzed by real-time polymerase chain reaction, complemented with catalase (CAT), glutathione S-transferase (GST), and acetylcholinesterase (AChE) activities. Few effects were observed at 24 h; however, after longer exposure (96 h), genes involved in the endocrine, detoxification, stress, and immune response pathways were altered. Moreover, fipronil at 96 h increased CAT and GST activity at 0.01 µg L-1 and AChE at the highest concentrations. The results demonstrate that even low environmentally relevant fipronil concentrations can modulate the molecular response of several cellular pathways in C. riparius after short-term exposure. These results bring new information about the underlying response of fipronil and its mode of action on a key aquatic invertebrate. Despite no effects on mortality, strong modulation at the suborganismal level emphasizes the advantage of biomarkers as early damage responses and the harmful impact of this pesticide on freshwater organisms. Environ Toxicol Chem 2024;43:405-417. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Isomer-specific analysis of nonylphenol and their transformation products in environment: A review

Nonylphenols (NPs) are crucial fine chemicals widely employed in producing industrial and consumer surfactants that ultimately enter the environment through various pathways, leading to environmental pollution. NPs are suspected endocrine-disrupting chemicals that may accumulate in the body over time, resulting in unusual reproductive function. Due to limitations in analytical methods, NPs have typically been quantified as a whole in some studies. However, NPs are a mixture of multibranched structures, and different NP isomers exhibit distinct environmental behaviors and toxic effects. Therefore, it is critical to analyze environmental and human biological samples at the isomer-specific level to elucidate the contamination characteristics, human exposure load, and toxic effects of NPs. Accurately analyzing NP samples with various isomers, metabolites, and transformation products presents a significant challenge. This review summarizes recent advances in analytical research on NPs in technical products, environmental, and human biological samples, particularly emphasizing the synthesis and separation of standards and the transformation of NP homolog isomers in samples. Finally, the review highlights the research gaps and future research directions in this domain.

New insights into the regulation mechanism of Pacific white shrimp (Litopenaeus vannamei) hepatopancreas under 4-nonylphenol exposure using transcriptome analysis

4-Nonylphenol (4-NP) is one of the common endocrine-disrupting chemicals (EDCs) in estuaries and coastal zones, which can exert detrimental effects on the physiological function of aquatic organisms. However, the molecular response triggered by 4-NP remains largely unknown in Pacific white shrimp (Litopenaeus vannamei). In this study, transcriptomic analysis was performed to investigate the underlying mechanisms of 4-NP toxicity in the hepatopancreas of L. vannamei. Nine RNA-Seq libraries were generated from L. vannamei at 0 h, 24 h, and 48 h following exposure to 4-NP. Compared with 0 h vs 24 h, 962 up- and 463 down-regulated differentially expressed genes (DEGs) were identified, indicating that many genes in L. vannamei were induced to resist adverse circumstances by 4-NP exposure. In contrast, 902 up- and 1027 down-regulated DEGs were revealed in the comparison of 0 h vs 48 h, demonstrating that prolonged exposure to the stress from 4-NP resulted in more inhibited genes. To validate the accuracy of the transcriptome data, eight DEGs were selected for quantitative real-time polymerase chain reaction (qRT-PCR), which were consistent with the RNA-Seq results. Through KEGG pathway enrichment analysis, three specific pathways related to hormonal effects and endocrine function of L. vannamei were enriched significantly, including tyrosine metabolism, insect hormone biosynthesis, and melanogenesis. After 4-NP stress, genes involved in tyrosine metabolism (Tyr) and melanogenesis pathway (AC, CBP, Wnt, Frizzled, Tcf, and Ras) were induced to promote melanin pigment to help shrimp resist adverse environments. In the insect hormone biosynthesis, ALDH, CYP15A1, CYP15A1/C1, and JHE genes were activated to synthesize juvenile hormone (JH), while Spook, Phm, Sad, and CYP18A1 were induced to generate molting hormone. There is an enhanced interaction between the molting hormone and JH, with JH playing a dominant role and maintaining its "classic status quo action". Our study demonstrated that 4-NP exposure led to impairments of biological functions in L. vannamei hepatopancreas. The genes and pathways identified provide novel insights into the molecular mechanisms underlying 4-NP toxicity effects in prawns and enrich the information on the toxicity mechanism of crustaceans in response to EDCs exposure.

An integrated in silico-in vitro investigation to assess the skin sensitization potential of 4-Octylphenol

One of the major challenges in chemical toxicity testing is the possibility to protect human health against adverse effects with non-animal methods. In this paper, 4-Octylphenol (OP) was tested for skin sensitization and immunomodulatory effects using an integrated in silico-in vitro test approach. In silico tools (QSAR TOOLBOX 4.5, ToxTree and VEGA) were used together with several in vitro tests including HaCaT cells (quantification of IL-6; IL-8; IL-1α and IL-18 by ELISA and expression of genes TNF, IL1A, IL6 and IL8 by RT- qPCR), RHE model (quantification of IL-6; IL-8; IL-1α and IL-18 by ELISA) and THP-1 activation assay (CD86/CD54 expression and IL-8 release). Additionally, the immunomodulatory effect of OP was investigated using lncRNAs MALAT1 and NEAT1 expression and LPS-induced THP-1 activation (CD86/CD54 expression and IL-8 release). The in silico tools predicted OP as a sensitizer. In vitro tests are also concordant with the in silico prediction. OP increased IL-6 expression (HaCaT cells); IL-18 and IL-8 expressions (RHE model). An irritant potential was also shown by a great expression of IL-1α (RHE model); and increased expression of CD54 marker and IL-8 in THP-1 cells. Immunomodulatory effects of OP were demonstrated by the downregulation of NEAT1, MALAT1 (epigenetic markers), IL6 and IL8; and an increase in LPS-induced CD54 and IL-8 expressions. Overall, results indicate that OP is a skin sensitizer, being positive in three key events of the AOP for skin sensitization, also showing immunomodulatory effects.

The effect of different doses of nonylphenol on the blood-testicular barrier integrity, hormone level, and DNA damage in the testes of rats

Determining the molecular characteristics of the damage caused by NP exposure in the testis is very important for understanding the source of the damage and developing treatment methods accordingly. Therefore, in this study, it is aimed to evaluate the toxic effects that different doses of NP may cause in the testis, including blood-testicular barrier integrity and sperm DNA damage. For this purpose, 50 adult male Wistar albino rats were used in the study. Low, medium, and high-dose NP groups and the corn oil group were formed. After NP administration at determined doses for 15 days, the testis tissue taken under anesthesia was fixed in formaldehyde. Paraffin blocks were embedded using the routine histological tissue follow-up method. Histopathological and immunohistochemical analyses were performed by taking 5 μm thick sections from paraffin blocks. The other testicular tissue was taken for the Western blot, Elisa, and comet methods, and the findings of sperm DNA analysis and the blood-testicular barrier were examined. NP caused the seminiferous epithelium to be disorganized and have significantly fewer cells in the testes of rats in different dose NP-induced groups. Compared with the control group, mTOR, Cx43, SCF, and HSP70 protein levels were decreased, while the expression of MMP-9 levels was increased in the different NP dose groups. Furthermore, tissue testosterone and inhibin B levels and SF-1 immunoreactivity intensity gradually decreased depending on the dose increase of NP. DNA damage of testicular tissues were increased in NP groups depending on NP dose. These results suggest that it is evident that NP, a commonly used industrial chemical, is an endocrine disrupting chemical (EDC) with estrogenic activity exerting adverse effects on health and that urgent measures are needed regarding the use.

Does environmental pollution affect male reproductive system in naturally exposed vertebrates? A systematic review

Due to environmental contamination, the environment constantly receives pollutants from various anthropic actions. These pollutants put ecological health at risk due to contamination and accumulation in living organisms, including wild animals and humans. Exposure can cause physiological, morphological, and behavioral changes in living beings. In this context, laboratory studies have frequently investigated how environmental contaminants affect the male reproductive system and gametes. However, few studies have examined how these contaminants affect male reproduction in naturally exposed animals. To better understand this topic, we conducted a systematic review of the effects of exposing male vertebrate animals to polluted environments on their reproductive functions. After an extensive search using the PubMed/MEDLINE, Scopus, and Web of Science databases, 39 studies met our inclusion criteria and were eligible for this review. This study showed that reproductive damages were frequent in fishes, amphibians, reptiles, birds, and mammals exposed to contaminated environments. Wild animals are exposed mainly to endocrine-disrupting compounds (EDCs), toxic metals, and radiation. Exposure to pollutants causes a reduction in androgen levels, impaired spermatogenesis, morphological damage to reproductive organs, and decreased sperm quality, leading to reduced fertility and population decline. Although several species have been studied, the number of studies is limited for some groups of vertebrates. Wildlife has proven valuable to our understanding of the potential effects of environmental contaminants on human and ecosystem health. Thus, some recommendations for future investigations are provided. This review also creates a baseline for the understanding state of the art in reproductive toxicology studies.

Nonylphenol Promoted Epithelial-Mesenchymal Transition in Colorectal Cancer Cells by Upregulating the Expression of Regulator of Cell Cycle

Nonylphenol (NP) is a widely used chemical, which has been considered a kind of endocrine-disrupting chemical and is involved in the occurrence and development of many types of cancers. Our recent studies demonstrated that NP exposure is related to colorectal cancer (CRC) progression. In this study, we also found epithelial-mesenchymal transition (EMT) promoted by NP treatment in CRC cells. However, the mechanism of NP on tumor metastasis is still unclear. In this study, we focused on the effect of the regulator of cell cycle (RGCC) induced by NP treatment. The cancer genome atlas (TCGA) analysis suggested that the expression of RGCC increased in CRC tissues, and our clinical samples showed that the expression of RGCC in tumor tissues is positively correlated with the serum level of NP in CRC patients. Further studies revealed that overexpression of RGCC could enhance the NP-induced EMT process in CRC cells and activate ERK signaling pathways. Inhibiting ERK signaling by ERK inhibitors or the knockdown of RGCC could attenuate the NP-induced EMT process. In addition, both RGCC overexpression and NP treatment could activate ERK pathways and attenuate the effect of ERK inhibitors on the EMT process in CRC cells. Altogether, this study demonstrated that NP could induce cell invasion and migration by increasing the expression of RGCC to enhance the EMT process, which might be through the activation of ERK signaling pathways. This finding supported a potential target for studying NP exposure-related colorectal cancers.

Iridoid glycoside Aucubin protects against nonylphenol-induced testicular damage in male rats via modulation of steroidogenic and apoptotic signaling

Aucubin (AU) is one of the widespread compounds belonging to the group of iridoid glycosides, which possesses numerous beneficial properties. Nonylphenol (NP), is a synthetic environmental toxicant that has the potential to cause male infertility through excessive production of reactive oxygen species. In the current study, the remedial potential of Aucubin was assessed against NP-generated testicular damage in male rats. Animals were distributed into four groups and treated for 56 days in this study. Control-group (0.1% DMSO + food), NP group (100 µg/kg), NP + AU group (100 µg/kg + 5 mg/kg) and AU group (5 mg/kg). NP exposure significantly (p < 0.05) reduced the activity of antioxidant enzymes i.e., glutathione reductase, catalase (CAT), superoxide dismutase, glutathione peroxidase (GPx), and total protein content (TPC), whereas the level of reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) was enhanced substantially (p < 0.05). Treatment with AU substantially (p < 0.05) recovered activities of antioxidant enzymes, TPC, ROS, and TBARS levels. Moreover, decrease in the levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), plasma testosterone, sperm count, motility, sperm membrane integrity, and the number of spermatocytes of different stages along with the level of steroidogenic enzymes i.e., 17β-hydroxysteroid dehydrogenase (17β-HSD), 3β-hydroxysteroid dehydrogenase (3β-HSD), and B-cell lymphoma 2 (Bcl-2) by NP administration were recovered to control values by AU treatment. However, AU mitigated the sperm abnormalities (head/midpiece/tail), the number of dead sperms, and proapoptotic proteins i.e., Bcl-2 associated X protein (Bax), caspase-9, and caspase-3 that were increased by NP. Besides, AU treatment recovered the NP-induced potential histopathological alterations in the testicular tissues such as the height of epithelium, seminiferous tubules diameter as well as the height of tunica propria. Overall, NP-induced toxicity was effectively recuperated by the AU administration. These results indicate that AU might be considered as a potential protective agent against testicular damage. The observed protection may be due to its antioxidant, anti-apoptotic, anti-inflammatory and androgenic potential.

Nonylphenol photodegradation by novel ternary MIL-100(Fe)/ZnFe2O4/PCN composite under visible light irradiation via double charge transfer process

Nonylphenol (NP) residues, as a typical endocrine disrupting chemical (EDC), frequently exist in sewage, surface water, groundwater and even drinking water, which poses a serious threat to human health due to its bioaccumulation. In order to remove NP, a series of MIL-100(Fe)/ZnFe₂O₄/flake-like porous carbon nitride (MIL/ZC) was synthesized through in-situ synthesis at room temperature. High performance of ternary MIL/ZC is used to degrade NP under visible light irradiation. The results show that 30MIL/ZC2 (20 wt.% ZnFe₂O₄) ternary composite had the best photocatalytic activity (99.84%) when the dosage was 30 mg. Further mechanism analysis shows that the excellent photocatalytic activity of 30MIL/ZC2 could be ascribed to the double charge transfer process between flake-like porous carbon nitride (PCN) and other catalysts in the ternary heterojunction, and the separation of photogenerated electron-hole pairs was more effective. In addition, the 30MIL/ZC2 also showed high stability after five cycles of the photodegradation reaction. Furthermore, the active substance (•O₂^-) was considered to be the main active substance in the NP degradation process. Based on the research results, the possible photocatalytic reaction mechanism of 30MIL/ZC2 ternary composite was proposed and discussed in detail.

Genotoxic activity of endocrine disrupting compounds commonly present in paper mill effluents

In the present study we evaluated cytotoxic and genotoxic activities of endocrine disrupting compounds (EDCs), including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), and nonylphenol (NP), which have been previously identified in effluents from two paper mills with different paper production technologies (virgin or recycled fibres). Moreover, we evaluated genotoxic activity of the effluents from these two paper mills and compared it to the activity of artificial complex mixtures consisting of the seven EDCs at concentrations detected in corresponding paper mill effluents. None of the EDCs was genotoxic in Salmonella typhimurium (SOS/umuC assay), while all induced DNA damage in human hepatocellular carcinoma (HepG2) cells (comet assay). After 4 h of exposure genotoxic effects were determined at concentrations ≥ 1 μg/L for BBP and DEHP, ≥10 μg/L for DMP, DEP, DBP, and BPA, and ≥100 μg/L for NP, while after 24 h of exposure DNA damage occurred at ≥10 μg/L for DBP, BPA and NP, and ≥100 μg/L for DMP, DEP, BBP and DEHP. The effluents and corresponding artificial mixtures of EDCs from paper mill that uses virgin fibres did not induce DNA damage in HepG2 cells, while the effluents and corresponding artificial mixtures for the paper mill that uses recycled fibres were genotoxic. Genotoxic activity of effluents was significantly higher compared to corresponding artificial mixtures suggesting the presence of further unknown compounds contributing to the effect. Wastewater monitoring based on chemical analysis is limited to determination of targeted compounds and does not take into account possible interactions between chemicals in mixtures. Therefore, it alone cannot provide an adequate information on potential toxic effects required for the assessment of genotoxic activity of real environmental samples and their potential threats to the environment and human health.

Single and mixture toxicity evaluation of three phenolic compounds to the terrestrial ecosystem

Endocrine-disrupting chemicals (EDCs) are primarily studied regarding endocrine-mediated effects in mammals and fish. However, EDCs can cause toxicity by mechanisms outside the endocrine system, and, as they are released continuously into soils, they may pose risks to terrestrial organisms. In this work, the plant Allium cepa and the earthworm Eisenia foetida were used as test systems to evaluate the toxicity and cyto-/geno-toxicity of three environmental phenols known as EDCs (Bisphenol A - BPA, Octylphenol - OP, Nonylphenol - NP). The tested phenols were evaluated in environmentally relevant concentrations (μg/L) and in single forms and mixture. BPA, OP, and NP did not inhibit the seed germination and root development in A. cepa in their single forms and mixture. However, all single forms of the tested phenols caused cellular and DNA damages in A. cepa, and although these effects persist in the mixtures, the effects were verified at lower levels. These phenols caused acute toxicity to E. foetida after 48 h of exposure and at both conditions evaluated (single forms and mixture); however, unlike A. cepa, in earthworms, mixtures and single forms presented the same level of effects, indicating that interspecies physiological different might influence the mixture toxicity. In summary, our results suggest that BPA, OP, and NP are toxicants to earthworm and cyto-/geno-toxicants to monocotyledonous plants at low concentrations. However, interaction among these phenols reduces the magnitude of their individual effects (antagonistic effect) in the plant test system. Therefore, this study draws attention to the need to raise knowledge about the ecotoxicity of phenolic compounds to help predict their ecological risks and protect non-target terrestrial species.

Damages to biological macromolecules in gonadal subcellular fractions of scallop Chlamys farreri following benzo[a]pyrene exposure: Contribution to inhibiting gonadal development and reducing fertility

Benzo[a]pyrene (B[a]P), a representative polycyclic aromatic hydrocarbon (PAH) compound in marine ecosystem, has great potential for chronic toxicity to marine animals. It is becoming increasingly apparent that reproductive system is the major target of B[a]P, but the adverse effects of B[a]P on subcellular fractions in bivalve gonads have not been elucidated. Scallops Chlamys farreri are used as the experimental species since they are sensitive to environmental pollutants. This study was conducted to investigate how B[a]P affected the gonadal subcellular fractions, including plasma membrane, nucleus, mitochondria and microsome in scallops, and whether subcellular damages were related to reproductive toxicity. The results showed that mature gametes' counts were significantly decreased in B[a]P-treated scallops. Three biological macromolecules (viz., DNA, lipids and proteins) in gonadal subcellular fractions obtained by differential centrifugation suffered damages, including DNA damage, lipid peroxidation and protein carbonylation in B[a]P treatment groups. Interestingly, mitochondria and microsome were more vulnerable to lipid peroxidation and protein carbonylation than plasma membrane and nucleus, meanwhile males were more susceptible to DNA damage than females under B[a]P exposure. In addition, histological analysis showed that B[a]P delayed gonadal development in C. farreri. To summarize, our results indicated that B[a]P caused damages to biological macromolecules in gonadal subcellular fractions and then induced damages to gonadal tissues of C. farreri, which further inhibited gonadal development and ultimately leaded to reduction in fertility. This study firstly reports the impacts of PAHs on subcellular fractions in bivalves and their relationship with reproductive toxicity. Moreover, exposure of reproductive scallops to B[a]P leads to defects in reproduction, raising concerns on the possible long-term consequences of PAHs for natural populations of bivalves.

Hazards of Chronic Exposure to Nonylphenol: Concomitant Effect on Non-alcoholic Fatty Liver Disease in Male Albino Rats

BACKGROUND: Chronic exposure to environmental endocrine disruptors like nonylphenol (NP), has been shown in previous studies to predispose to non-alcoholic fatty liver disease. METHODS: In this work, forty adult male albino rats were divided into four groups, a high sucrose-high-fat diet (HSHFD) group, a group receiving 20 μg/kg/day of NP, an NP + HSHFD group, and a control group. The rats were sacrificed on day 60 after anesthetization. RESULTS: Biochemical tests indicated that serum transaminases (alanine aminotransferase, aspartate aminotransferase) were significantly increased in the NP + HSHFD group. Lipid metabolism was most disrupted in the NP + HSHFD with a highly significant increase (p < 0.001) of serum cholesterol, triglyceride, and low-density lipoprotein cholesterol compared to other groups. Heme oxygenase 1 showed the highest expression in the NP + HSHFD group, with a highly significant difference in comparison with the other groups (p < 0.001). Histopathological studies revealed fatty changes and dilatation in the central vein in the HSHFD group. Lymphoid cell aggregates were detected in the NP group. Massive inflammation and degeneration were revealed in the NP + HSHFD group. There was also marked expression of the apoptotic protein caspase-3 in the NP + HSHFD group. CONCLUSION: In conclusion, exposure to a 20 μg/kg/day of NP induced oxidative stress leading to non-alcoholic steatohepatitis.

Effects of nonylphenol exposure on histological changes, apoptosis and time-course transcriptome in gills of white shrimp Litopenaeus vannamei

Nonylphenol (NP) is considered as one of the persistent organic pollutants (POPs) in the environment. Pacific white shrimp Litopenaeus vannamei is the predominant species in China, which is frequently affected by environmental pollutants. However, potential toxicity mechanism of NP in shrimp has not been comprehensively studied. To explore the physiological changes and molecular mechanism involved in NP exposure of shrimp, we analyzed histological alterations, apoptosis and transcriptional responses of L.vannamei subjected to NP. Results indicated that significant changes in the histoarchitecture of the gills were observed after NP exposure for 3, 12 and 48 h. Apoptosis was also detected in a time-dependent manner. Numerous differentially expressed genes (DEGs) were obtained at 3 h, 12 h and 48 h after exposure. On the basis of the expression patterns over the time course, these DEGs were classified into 12 clusters. GO and KEGG enrichment analysis of these DEGs was carried out and a dynamic and global view was obtained in shrimp after NP exposure on a transcriptome level. In addition, 15 DEGs involved in immune response, apoptosis, DNA repair, osmoregulation etc. were selected for qRT-PCR validation. The expression patterns of these DEGs kept a well consistent with the high-throughput data at different timepoints, which confirmed the accuracy and reliability of the transcriptome data. All the results demonstrated that NP exposure might lead to impairments of biological functions in gills, alter immune and antioxidant response, compromise DNA repair and anti-apoptosis abilities of shrimp, cause severe histopathological changes and eventually trigger apoptosis. The present study enriched the information on the toxicity mechanism of crustaceans in response to NP exposure.

Protective Effect of Sodium Selenite on 4-Nonylphenol-Induced Hepatotoxicity and Nephrotoxicity in Rats

This study was aimed at evaluating the protective effect of sodium selenite (SS) on DNA integrity, antioxidant/oxidant status, and histological changes on 4-nonylphenol (4-NP)-induced toxicity in liver and kidney tissues of rats. Twenty-four adult male Sprague Dawley rats were divided into 4 groups as control, SS, 4-NP, and SS+4-NP group. Control group was untreated. The SS group was supplemented with SS (0.5 mg/kg/day) and the 4-NP group was given 4-NP (125 mg/kg/day). The rats in the SS+4-NP group received SS followed by 4-NP 1 h later at the abovementioned doses. The treatments were administered by oral gavage for 48 days. DNA damage was analyzed by comet assay in lymphocytes. Oxidative stress parameters were measured, and histological evaluation was performed in liver and kidney tissues. Results showed that SS administration significantly decreased % Tail DNA and Mean Tail Moment in SS+4-NP group as compared with 4-NP group. Catalase activity in liver was significantly lower in 4-NP group only. SS treatment significantly increased the glutathione level and decreased high malondialdehyde level in tissues of the SS+4-NP group as compared with 4-NP group. Dilation of central vein, ballooning degeneration, vacuolar degeneration, and deterioration in the structure of remark cords in 4-NP-administered were alleviated in rats that received SS supplementation before administration of 4-NP. Moreover, glycogen intensity in hepatocytes and the wall of central vein increased in the SS+4-NP group. In addition, the SS supplementation in the SS+4-NP group decreased glomerular degeneration as well as the width of cavum glomeruli and congestion intensity in the kidney. These results indicate that SS may have a protective effect against 4-NP-induced hepato-nephrotoxicity in rats.

The mechanism of cytotoxicity of 4-nonylphenol in a human hepatic cell line involves ER-stress, apoptosis, and mitochondrial dysfunction

4-Nonylphenol (4-NP) is an emerging environmental pollutant widely diffused in waters and sediments. It mainly derives from the degradation of alkyl phenol ethoxylates, compounds commonly employed as industrial surfactants. 4-NP strongly contaminates foods and waters for human use; thus, it displays a wide range of toxic effects not only for aquatic organisms but also for mammals and humans. After ingestion through the diet, it tends to accumulate in body fluids and tissues. One of the main organs where 4-NP and its metabolites are concentrated is the liver, where it causes, even at low doses, oxidative stress and apoptosis. In the present study, we analyzed the effects of 4-NP on a human hepatic cell line (HepG2) to deepen the knowledge of its cytotoxic mechanism. We found that 4-NP, in a range of concentration from 50 to 100 μM, significantly reduced cell viability; it caused a partial block of proliferation and induced apoptosis with activation of caspase-3 and overexpression of p53. Moreover, 4-NP induced-apoptosis seemed to involve both an ER-stress response, with the appearance of high level of GRP78, CHOP and the spliced XBP1, and a dysregulation of mitochondrial physiology, characterized by an overexpression of main markers of mitochondrial dynamics. Our data support the idea that a daily consumption of 4-NP-contaminated foods may lead to local damages at the level of gastrointestinal system, including liver, with negative consequences for the organ physiology.

Transcriptomic analysis of nonylphenol effect on Saccharomyces cerevisiae

Nonylphenol (NP) is a bioaccumulative environmental estrogen that is widely used as a nonionic surfactant. We have previously examined short-term effects of NP on yeast cells using microarray technology. In the present study, we investigated the adaptive response of Saccharomyces cerevisiae BY4742 cells to NP exposure by analyzing genome-wide transcriptional profiles using RNA-sequencing. We used 2 mg/L NP concentration for 40 days of exposure. Gene expression analysis showed that a total of 948 genes were differentially expressed. Of these, 834 genes were downregulated, while 114 genes were significantly upregulated. GO enrichment analysis revealed that 369 GO terms were significantly affected by NP exposure. Further analysis showed that many of the differentially expressed genes were associated with oxidative phosphorylation, iron and copper acquisition, autophagy, pleiotropic drug resistance and cell cycle progression related processes such as DNA and mismatch repair, chromosome segregation, spindle checkpoint activity, and kinetochore organization. Overall, these results provide considerable information and a comprehensive understanding of the adaptive response to NP exposure at the gene expression level.

Reduced phytotoxicity of nonylphenol on tomato (Solanum lycopersicum L.) plants by earthworm casts

Concentrations as high as thousands of milligrams per kilogram (dry weight) of nonylphenol (NP), an endocrine-disrupting chemical of great concern, have been reported in soil. Soil is considered one of the primary pathways for exposure of crop plants to NP. However, there have been few studies on the toxicity of soil NP to crop plants, especially with comprehensive consideration of the application of organic fertiliser which is a common agricultural practice. In this study, tomato plants were grown in soils treated with NP in the presence and/or absence of earthworm casts (EWCs). After four weeks, we tested the physiological and biochemical responses (accumulative levels of hydrogen peroxide (H₂O₂) and superoxide anion radicals (O₂-·), total chlorophyll content, degree of membrane lipid peroxidation, activities of defence-related enzymes, and level of DNA damage) and the changes in plant growth (elongation and biomass). The growth inhibition, reactive oxygen species (H₂O₂ and O₂-·) accumulation, decrease in chlorophyll content, increase in activity of defence-related enzymes (including superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, glutathione S-transferase and glutathione reductase), enhancement of membrane lipid peroxidation, and DNA damage in NP-treated seedlings were clearly reversed by the intervention of EWCs. In particular, the suppressed elongation, biomass, and chlorophyll content in tomato plants exposed to NP alone were significantly restored by EWCs to even greater levels than those of the undisturbed control. In other words, EWCs could efficiently invigorate the photosynthesis of crops via up-regulating the chlorophyll content, thereby overwhelming the NP stress on plant growth. Accordingly, except for reducing the bioavailability of soil NP as reported in our previous study, EWCs could also help crop plants to cope with NP stress by strengthening their stress resistance ability. Our findings are of practical significance for the formulation of strategies to relieve the negative effects of soil NP on crop growth.

Immune and bioinformatics identification of T cell and B cell epitopes in the protein structure of SARS-CoV-2: A systematic review

The beginning of 2020 was marked as the emergence of a COVID-19 outbreak caused by a new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, there is no vaccine or approved treatment for this infectious virus so the invention of an efficient vaccine is certainly a high priority. Some studies have employed several techniques to facilitate the combination of the immunoinformatics approach and comparative genomic approach in order to determine the potential peptides for designing the T-cell epitope-based peptide vaccine using the 2019-nCoV envelope protein as a target. Via screening the bioimmunoinformatic SARS-CoV2 derived B-cell and T-cell epitopes within the basic immunogenic of SARS-CoV2 proteins, we presented a set of inferred B-cell and T-cell epitopes from the spike (S) and nucleocapsid (N) proteins with high antigenicity and without allergenic property or toxic effects. Our findings provide a screened set of epitopes that can be introduced as potential targets for developing peptide vaccines against the SARS-CoV-2 virus.

Non-targeted detection and differentiation of agonists versus antagonists, directly in bioprofiles of everyday products

Xenoestrogens exert antiandrogenic effects on the human androgen receptor. In the analytical field, such antagonists block the detection of testosterone and falsify results obtained by sum parameter assays. Currently, such agonistic versus antagonistic effects are not differentiated in complex mixtures. Oppositely acting hormonal effects present in products of everyday use can only be differentiated after tedious fractionation and isolation of the individual compounds along with subjection of each fraction/compound to the status quo bioassay testing. However, such long-lasting procedures are not suited for routine. Hence, we developed a fast bioanalytical tool that figures out agonists versus antagonists directly in complex mixtures. Exemplarily, 8 cosmetics and 15 thermal papers were analyzed. The determined antagonistic potentials of active compounds found were comparable to the ones of known antagonists (in reference shown for bisphenol A, 4-n-nonylphenol and four parabens). Relevant biological/chromatographic parameters such as cell viability, culture conditions, dose response curves, limits of biological detection/quantification and working range (shown for testosterone, dihydrotestosterone, nandrolone and trenbolone) were investigated to obtain the best sensitivity of the biological detection. The developed and validated method was newly termed reversed phase high-performance thin-layer chromatography planar yeast ant-/agonistic androgen screen (RP-HPTLC-pYAAS bioassay). Results were also compared with the RP-HPTLC-Aliivibrio fischeri bioassay (applied on RP plates for the first time). As proof-of-concept, the transfer to another bioassay (RP-HPTLC-pYES) was successfully demonstrated, analogously termed RP-HPTLC-pYAES bioassay detecting anti-/estrogens (exemplarily shown for evaluation of 4 pharmaceuticals used in breast cancer treatment). The new imaging concept provides (1) detection and differentiation of individual agonistic versus antagonistic effects in the bioprofiles, (2) bioanalytical quantification of their activity potential by scanning densitometry and (3) characterization of unknown bioactive compound zones by hyphenation to high-resolution mass spectrometry. Depending on the hormonal bioassay, 15 samples were analyzed in parallel within 5 h or 6 h (calculated as 20 or 24 min per sample). For the first time, piezoelectric spraying of the yeast cells was successfully demonstrated for the planar yeast-based bioassays.

Environmental exposure to nonylphenol and cancer progression Risk-A systematic review

Environmental exposure to nonylphenol (NP) can adversely affect human and wildlife health. A systematic review was conducted to evaluate the relationship between environmental NP exposure and cancer progression risk. Literature surveys were conducted within several international databases using appropriate keywords. A comprehensive search yielded 58 eligible studies involving a wide range of adverse effects, exposure assessment methods, study designs, and experimental models. Most studies reported that NP strongly induced breast cancer progression in intended experiments. Positive associations between NP exposure and ovarian, uterine, pituitary, and testicular cancers were also reported. Although some studies reported no relation between environmental NP exposure and tumour and/or cancer progression, NP (a known endocrine disrupting chemical) induced action mechanisms in multiple experimental models and may interfere with/hyper-activate oestrogen signalling. Secretion of oestrogen and development of reproductive tissues like breasts, uteruses, and ovaries showed strong associations with possible neoplasia (i.e., uncontrolled development of tumours and/or malignant cancers). Findings of this study are important for informing policymakers to pass legislation limiting the use of environmental contaminants such as NP before all adverse effects of exposure have been determined.

Adverse Effect of Nonylphenol on the Reproductive System in F1 Male Mice: A Subchronic Low-Dose Exposure Model

Nonylphenols (NPs) are widely used industrial materials, and are considered as potent endocrine disrupting chemical. Present study was undertaken to clarify the effect of subchronic low-dose NP exposure to F1 generation male mice. Mice were divided into 2 groups; (1) CON, control animals and (2) NP-50 (50 μg/L), animals were treated with NP via drinking water. NP exposures were continuously conducted from parental pre-mating period until the postnatal day (PND) 55 of F1 offsprings. Mice were sacrificed on PND 55 and the tissue weights were measured. The initial body weights (at PND 21) and terminal body weights (PND 55) of the NP-50 animals were significantly lower than those of control animals (p<0.05). NP exposure induced a significant increase in the absolute weight of the testes (p<0.05). Conversely, the NP exposure caused significant decrease in the absolute weights of the epididymis (p<0.01), prostate (p<0.05) and seminal vesicle (p<0.05). Histopathological studies revealed that NP-treated animals exerted decreased seminiferous tubule diameters, reduced luminal area, and lower number of germ cells. Also some sloughing morphologies in the tubules were observed. In the caudal epididymis, fewer mature sperms and swollen epithelial cells were found in the NP-treated group. Our results confirmed that the subchronic low-dose NP exposure altered some male parameters and induced histopathological abnormalities in testis and epididymis of F1 mice. Since the NP dose used in this study is close to the average human daily NP exposure, our results could provide practically meaningful understanding of adverse effect of EDC in human.

In vivo evaluation of the genotoxicity and oxidative damage in individuals exposed to 10% hydrogen peroxide whitening strips

OBJECTIVE

This study assessed the impact of 10% hydrogen peroxide whitening strip exposure on the genotoxicity and oxidative damage by means of the buccal micronucleus cytome assay by counting nuclear abnormalities (NAs) in buccal mucosa and attached gingiva cells and by analyzing in whole saliva the molecule 8-hydroxy-2'-deoxyguanosine (8-OHdG).

MATERIALS AND METHODS

The study was conducted on 113 subjects divided into two groups: group 1 or control (n = 53), non-whitening strip exposed, and group 2 (n = 60), whitening strip exposed (Crest® 3D Whitestrips® premium plus, 10% hydrogen peroxide). Oral epithelial cells and whole saliva samples were taken at the beginning and 30 days later for group 1 and immediately before bleaching and 15 and 30 days after the end of the bleaching for group 2.

RESULTS

An increased frequency of NAs (p < 0.05) and higher levels of 8-OHdG (p < 0.05) were observed after bleaching exposure. Also, a positive correlation exists between oxidative stress produced by hydrogen peroxide and micronuclei was found.

CONCLUSION

Individuals exposed to 10% hydrogen peroxide whitening strips exhibit NAs increased in oral epithelial cells and 8-OHdG in saliva, which is directed related to nuclear and oxidative DNA damage, respectively.

CLINICAL SIGNIFICANCE

Hydrogen peroxide is the active agent of tooth whitening and this compound induced DNA damage. Individuals exposed to whitening strips with 10% hydrogen peroxide exhibit increased genotoxic and oxidative damage. Therefore, self-application of bleaching agents should be handled carefully since it could be a risk to human health.