Nonylphenol in pregnant women and their matching fetuses: placental transfer and potential risks of infants

Association of alkylphenols exposure with serum liver function markers in pregnant women in Guangxi, China

The liver toxicity of alkylphenols (APs) has been demonstrated in animal studies. However, relevant epidemiological evidence is still lacking in humans, especially during pregnancy. We obtained the levels of biochemical indicators of liver function in early (<13 weeks, mean gestation=9.80±1.96 weeks) and late (≥32 weeks, mean gestation = 37.23±2.45 weeks) pregnancies from 219 pregnant women in the Guangxi Zhuang birth cohort from 2015-2017. We also examined the serum levels of APs in these pregnant women in early pregnancy. The present study aimed to investigate the correlations between the exposure of pregnant women to APs and their serum liver function indices. The results of the generalized linear model (GLM) in this study revealed that nonylphenol (NP) was positively correlated with total bilirubin (TBIL) (P=0.04) in early pregnancy, and 4-n-nonylphenol (4-N-NP) was negatively correlated with glutamyl transferase (GGT) (P=0.012). In late pregnancy, NP was positively associated with TBIL (P=0.002), and 4-tert-octylphenol (4-T-OP) was positively correlated with alanine aminotransferase (ALT) (P=0.02). Restricted cubic spline (RCS) results revealed doseresponse relationships between NP and TBIL (Poverall=0.011) and between 4-N-NP and GGT (Poverall=0.007) in early pregnancy. In late pregnancy, there were doseresponse relationships between NP and TBIL (Poverall=0.001) and between 4-T-OP and ALT (Poverall=0.033). There was also a doseresponse relationship between NP volume and GGT with an inverted 'U' shape (Poverall=0.041, Pnonlinear=0.012). Bayesian kernel machine regression modeling (BKMR) revealed that TBIL increased significantly (P<0.05) with increasing levels of coexposure to APs in both early and late pregnancy. Overall, exposure to APs during pregnancy affects maternal liver function to varying degrees. The present study provides new epidemiological evidence that exposure to alkylphenols in pregnant women interferes with liver function.

Probabilistic risk assessment of dietary exposure to benzophenone derivatives in cereals in Taiwan

Benzophenone (BP) and BP derivatives (BPDs) are widely used as ultraviolet (UV) stabilizers in food packaging materials and as photoinitiators in UV-curable inks for printing on food-contact materials. However, our knowledge regarding the sources and risks of dietary exposure to BP and BPDs in cereals remains limited, which prompted us to conduct this study. We measured the levels of BP and nine BPDs-BP-1, BP-2, BP-3, BP-8, 2-hydroxybenzophenone, 4-hydroxybenzophenone, 4-methylbenzophenone (4-MBP), methyl-2-benzoylbenzoate, and 4-benzoylbiphenyl-in three types of cereals (rice flour, oatmeal, and cornflakes; 180 samples in total). A Bayesian Markov-chain Monte Carlo (MC) simulation approach was used for deriving the posterior distributions of BP and BPD residues. This approach helped in addressing the uncertainty in probabilistic distribution for the sampled data under the detection limit. Through an MC simulation, we calculated the daily exposure levels of dietary BP and BPDs and corresponding health risks. The results revealed the ubiquitous presence of BP, BP-3, and 4-MBP in cereals. Older adults (aged >65 years) had the highest (97.5 percentile) lifetime carcinogenic risk for BP exposure through cereals (9.41 × 10-7), whereas children aged 0-3 years had the highest (97.5 percentile) hazard indices for BPD exposure through cereals (2.5 × 10-2). Nevertheless, across age groups, the lifetime carcinogenic risks of BP exposure through cereals were acceptable, and the hazard indices for BPD exposure through cereals were <1. Therefore, BPD exposure through cereals may not be a health concern for individuals in Taiwan.

Nonylphenol ethoxylate degradation in detergents during shelf time, a new exposure pathway, and a perspective on their substitution

Detergents are highly produced pollutants with environmental problems like foam generation and toxic effects in biota. Nonylphenol ethoxylates (NPEs) are efficient, economical, and versatile surfactants, used in detergents for more than 40 years due to their detergency capacity. In the environment, NPE biodegrades into the metabolite nonylphenol (NP), classified as an endocrine disruptor. The identification and quantification of 4-NP in a designed detergent and 30 commercially available detergents were performed to prove the degradation of NPE into 4-NP during storage time. This investigation introduces the first evidence of NPE degradation during storage in commercially available detergents, demonstrating a novel exposure pathway in humans that has not been explored before, representing potential human health risks. Therefore, simple, easy, low-cost, and available approaches to remove and substitute NP is paramount. Alkyl polyglucoside (APG) was assessed as a substitute, and the feasibility of this substitution was proven according to physical and chemical properties, cleaning performance, and antimicrobial properties. NPE substitution in detergents is demonstrated as a viable strategy to minimize exposure risks in humans and the environment.

Regulatory mechanism of perinatal nonylphenol exposure on cardiac mitochondrial autophagy and the PINK1/Parkin signaling pathway in male offspring rats

OBJECTIVE

This study investigated whether perinatal exposure to nonylphenol (NP) induces mitochondrial autophagy (i.e., mitophagy) damage in neonatal rat cardiomyocytes (NRCMs) and whether the PINK1/Parkin signaling pathway is involved in NP-induced primary cardiomyocyte injury.

METHODS AND RESULTS

In vivo: Perinatal NP exposure increased apoptosis and mitochondrial damage in NRCMs. Mitochondrial swelling and autophagosome-like structures with multiple concentric membranes were observed in the 100 mg/kg NP group, with an increase in the number of autophagosomes. Disorganized fiber arrangement and elevated serum myocardial enzyme levels were observed with increasing NP dosage. Additionally, NP exposure led to increased MDA levels and decreased SOD activity and ATP levels in myocardial tissue. The mRNA expression levels of autophagy-related genes, including Beclin-1, p62, and LC3B, as well as the expression of mitochondrial autophagy-related proteins (PINK1, p-Parkin, Parkin, Beclin-1, p62, LC3-I, LC3-II, and LC3-II/I) and apoptosis-related proteins (Bax and caspase-3), increased, whereas the expression levels of the mitochondrial membrane protein TOMM20 and the anti-apoptotic protein Bcl-2 decreased. In vitro: NP increased ROS levels, LDH release, and decreased ATP levels in NRCMs. CsA treatment significantly inhibited the expression of autophagy-related proteins (Beclin-1, LC3-II/I, and p62) and apoptosis-related proteins (caspase-3 and Bax), increased the expression levels of TOMM20 and Bcl-2 proteins, increased cellular ATP levels, and inhibited LDH release. The inhibition of the PINK1/Parkin signaling pathway suppressed the expression of mitochondrial autophagy-related proteins (PINK1, p-Parkin, Parkin, Beclin-1, LC3-II/I, and p62) and apoptosis-related proteins (caspase-3 and Bax), increased TOMM20 and Bcl-2 protein expression, increased ATP levels, and decreased LDH levels in NRCMs.

CONCLUSIONS

This study is novel in reporting that perinatal NP exposure induced myocardial injury in male neonatal rats, thereby inducing mitophagy. The PINK1/Parkin signaling pathway was involved in this injury by regulating mitophagy.

Bioaccumulation and in vivo tracking of radiolabeled 4-nonylphenol in mice

4-Nonylphenol (4NP) is concerning due to its growing presence and endocrine-disrupting nature, raising concerns about its impact on health. In this study 124I-labeled 4NP was synthesized for in vivo tracing. Positron emission tomography imaging and biodistribution studies showed significant accumulation in various tissues after oral or intraperitoneal administration, emphasizing its intricate distribution and potential long-term effects, crucial for future risk assessments.

Myocardial fibrosis induced by nonylphenol and its regulatory effect on the TGF-β1/LIMK1 signaling pathway

OBJECTIVE

We here explored whether perinatal nonylphenol (NP) exposure causes myocardial fibrosis (MF) during adulthood in offspring rats and determined the role of the TGF-β1/LIMK1 signaling pathway in NP-induced fibrosis in cardiac fibroblasts (CFs).

METHODS AND RESULTS

Histopathology revealed increased collagen deposition and altered fiber arrangement in the NP and isoproterenol hydrochloride (ISO) groups compared with the blank group. Systolic and diastolic functions were impaired. Western blotting and qRT-PCR demonstrated that the expression of central myofibrosis-related proteins (collagens Ι and ΙΙΙ, MMP2, MMP9, TGF-β1, α-SMA, IL-1β, and TGF-β1) and genes (Collagen Ι, Collagen ΙΙΙ, TGF-β1, and α-SMA mRNA) was upregulated in the NP and ISO groups compared with the blank group. The mRNA-seq analysis indicated differential expression of TGF-β1 signaling pathway-associated genes and proteins. Fibrosis-related protein and gene expression increased in the CFs stimulated with the recombinant human TGF-β1 and NP, which was consistent with the results of animal experiments. According to the immunofluorescence analysis and western blotting, NP exposure activated the TGF-β1/LIMK1 signaling pathway whose action mechanism in NP-induced CFs was further validated using the LIMK1 inhibitor (BMS-5). The inhibitor modulated the TGF-β1/LIMK1 signaling pathway and suppressed the NP-induced increase in fibrosis-related protein expression in the CFs. Thus, the aforementioned pathway is involved in NP-induced fibrosis.

CONCLUSION

We here provide the first evidence that perinatal NP exposure causes myocardial fibrosis in growing male rat pups and reveal the molecular mechanism and functional role of the TGF-β1/LIMK1 signaling pathway in this process.

Assessment of nonylphenol exposure based on global urinary concentration data and its risk analysis

Nonylphenol (NP) has been recognized as a priority hazardous substance because of its estrogenic activity and ubiquity in the environment. Therefore, it is important to understand the daily intake of NP in humans and evaluate the potential health risks of NP. The median or average estimated daily intake (EDI) of NP was estimated based on urinary NP or alkyl-chain-oxidized NP metabolites concentration data from published epidemiological studies. In brief, we acquired 34 peer-reviewed publications, which contained 14235 samples from twelve countries or regions. The global average estimated daily intake of NP was 1.003 μg/(kg bw·day), which was lower than the tolerable daily intake recommended by the Danish Veterinary and Food Authority [5 μg/(kg bw·day)]. Korea had the highest exposure level [3.471 μg/(kg bw·day)] among different countries or regions. Compared with the adult [0.743 μg/(kg bw·day)] and pregnant women [0.806 μg/(kg bw·day)] groups, the children group had the highest estimated daily intake of NP at 2.368 μg/(kg bw·day). Besides, the global NP risk hazard quotient was 0.201, and the risk hazard quotients of all countries or regions were less than 1. However, the global HQ value of the 95th quantile population was 2.299, which was much higher than 1, the potential health risk cannot be ignored and needs to be confirmed by more research. To our knowledge, this is the first study to assess the overall NP exposure levels based on published biomonitoring data, and has important implications for assessing the potential effects of NP exposure on human health. In addition, OH-NP is a robust and sensitive novel biomarker for NP, there are fewer studies on the application of this biomarker, and more studies are needed in the future for quantitative exposure and risk assessment of NP.

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.

Association between prenatal exposure to alkylphenols and intelligence quotient among preschool children: sex-specific effects

BACKGROUND

While prenatal exposure to alkylphenols (APs) has been demonstrated to be associated with neurodevelopmental impairments in animals, the evidence from epidemiological studies remains limited and inconclusive. This study aimed to explore the link between AP exposure during pregnancy and the intelligence quotient (IQ) of preschool children.

METHODS

A total of 221 mother-child pairs from the Guangxi Zhuang Birth Cohort were recruited. Nonylphenol (NP), 4-tert-octylphenol (4-T-OP), 4-n-nonylphenol (4-N-NP), and 4-n-octylphenol were measured in maternal serum in early pregnancy. Childhood IQ was evaluated by the Fourth Edition of Wechsler Preschool and Primary Scale of the Intelligence at 3 to 6 years of age. The impact of APs on childhood IQ were evaluated by generalized linear models (GLMs), restricted cubic spline (RCS), and Bayesian kernel machine regression (BKMR).

RESULTS

In GLMs, prenatal exposure to NP and the second tertile of 4-T-OP exhibited an inverse association with full-scale IQ (FSIQ) (β = -2.38; 95% CI: -4.59, -0.16) and working memory index (WMI) (β = -5.24; 95% CI: -9.58, -0.89), respectively. Prenatal exposure to the third tertile of 4-N-NP showed a positive association with the fluid reasoning index (β = 4.95; 95% CI: 1.14, 8.77) in total children, as well as in girls when stratified by sex. A U-shaped relationship between maternal 4-T-OP and WMI was noted in total children and girls by RCS (all P nonlinear < 0.05). The combined effect primarily driven by NP, of maternal AP mixtures at concentrations above the 50th percentile exhibited an inverse trend on FSIQ in total children and girls in BKMR.

CONCLUSIONS

Prenatal exposure to various APs affects IQ in preschool children, and there may be nonmonotonic and sex-specific effects. Further investigation across the population is required to elucidate the potential neurotoxic effects of APs.

Prenatal to preschool exposure of nonylphenol and bisphenol A exposure and neurodevelopment in young children

BACKGROUND

Nonylphenol (NP) and bisphenol A (BPA) are produced in large quantities worldwide as multipurpose agents. However, studies on relations between NP and BPA exposure and childhood neurodevelopment are few, and the results are inconsistent. This study aimed to investigate associations between prenatal and early childhood NP and BPA exposure and neurodevelopment in mother-child pairs.

METHODS

Pregnant women at 27-38 weeks' gestation were recruited, as were children 2-3 years of age (n = 94) and 4-6 years of age (n = 56) years. Urine was collected to assess NP and BPA exposure. Bayley Scales of Infant and Toddler Development (3rd edition; Bayley-III), Wechsler Preschool and Primary Scale of Intelligence (4th edition), and the Full Scale Intelligence Quotient (WPPSI-IV-FSIQ) were used to assess the neurodevelopment of the children.

RESULTS

The detection rate and concentration of NP and BPA in the urine of children 4-6 years old were higher than in those 2-3 years old. Children were divided into a high concentration group (3rd tertile) and a reference group (1st and 2nd tertiles) based on natural log-transformed urine concentration of NP and BPA. Girls' Bayley-III motor scores in the high concentration group were higher than those of the BPA reference group of urine of mothers (β = 6.85, 95% confidence interval [CI]: 1.58-12.13). Boys' FSIQ in the higher concentration group were significantly lower than those in children 2-3 years old in the NP reference group (β = -11.29, 95% CI: -18.62 to -3.96) (all, p < 0.05).

CONCLUSIONS

Prenatal and childhood exposure to NP and BPA may have different effects on the neurodevelopment of young children, and there are no consistent effects between boys and girls.

Triple-Mode Sensor Coupled by Photoelectrochemical, Electrochromic, and Spectral Signals for Sensitive Visualized Detection of Nonylphenol

Conventional photoelectrochemical (PEC) biosensors suffer from the difficulty of visualizing rapid detection and limited accuracy due to a single-signal output. Here, we develop a PEC, electrochromic (EC), and spectral (ST) triple-mode platform for the sensitive visualized detection of nonylphenol (NP). First, the reasonably stepped Fermi energy level arrangement between the defective TiO2 anode and MoO3 cathode enables a remarkable photocurrent response (Mode 1). Then, MoO3 itself is a widely used EC candidate, which can react with free Li-ions to form a LixMoO3 intermediate, and its color will change from white to blue accordingly (Mode 2). More importantly, MoO3 is also a Li-ion host and the potential of LixMoO3 depends on the inserted Li-ion quantity deduced by spectral analysis on residual Li-ions in the electrolyte (Mode 3). The EC signal endows fast visual detection, and triple-mode cross-validation improves reliability and accuracy. As a result, this PEC-EC-ST triple-mode molecularly imprinted sensor has a wide linear range (1-5000 μg L-1), a low detection limit (0.18 μg L-1), selectivity, stability, reproducibility, and actual sample detection capability. This innovative multimode platform not only improves detection reliability but also broadens applications of electrochromic/energy storage materials in biosensors.

Relationship between Eating Habits and 4-Nonylphenol Concentration in Breast Milk of Women in Slovakia

4-Nonylphenol belongs to the alkylphenol group of chemicals, and its high occurrence in the environment can cause an adverse effect on human health. Breast milk can serve as a marker to take measure of human exposure to these chemicals through different routes of exposure. In this work, the influence of selected factors (the kind of water drank by the mothers; the consumption of fish, pork, and beef; wearing gloves; using nail polish, gel nails, vitamins, and medication) on the concentration on 4-nonylphenol in 89 breast milk samples was studied. The concentrations of nonylphenol in breast milk were determined by HPLC with fluorescence detection. The lowest and highest concentrations of 4-nonylphenol in breast milk were 0.97 ng/mL and 4.37 ng/mL, respectively. Statistical significance was observed for the consumption of pork (p = 0.048) and fish (0.041) in relation to the 4-nonylphenol concentration. Certain parameters (use of gel nails, beef consumption, and vitamin supplementation) were at the border of statistical significance (p = 0.06). Other parameters did not show any statistical significance. The results showed that breast milk in Slovakia does not contain a harmful dose of 4-nonylphenol and does not cause health problems. But it is necessary to continue this research and perform extended screening on a larger number of samples.

Environmental contamination status with common ingredients of household and personal care products exhibiting endocrine-disrupting potential

The continuous use of household and personal care products (HPCPs) produces an immense amount of chemicals, such as parabens, bisphenols, benzophenones and alkylphenol ethoxylates, which are of great concern due to their well-known endocrine-disrupting properties. These chemicals easily enter the environment through man-made activities, thus contaminating the biota, including soil, water, plants and animals. Thus, on top of the direct exposure on account of their presence in HPCPs, humans are also susceptible to secondary indirect exposure attributed to the ubiquitous environmental contamination. The aim of this review was therefore to examine the sources and occurrence of these noteworthy contaminants (i.e. parabens, bisphenols, benzophenones, alkylphenol ethoxylates), to summarise the available research on their environmental presence and to highlight their bioaccumulation potential. The most notable environmental contaminants appear to be MeP and PrP among parabens, BPA and BPS among bisphenols, BP-3 among benzophenones and NP among alkylphenols. Their maximum detected concentrations in the environment are mostly in the range of ng/L, while in human tissues, their maximum concentrations achieved μg/L due to bioaccumulation, with BP-3 and nonylphenol showing the highest potential to bioaccumulate. Finally, of another great concern is the fact that even the unapproved parabens and benzophenones have been detected in the environment.

Nonylphenol induces anxiety-like behavior in rats by regulating BDNF/TrkB/CREB signal network

This study aimed to verify whether chronic exposure to nonylphenol (NP) induces anxiety behavior in rats and explored NP's regulatory effect on the BDNF/TrkB/CREB signal network in vitro. Anxiety-like behavior was assessed by elevated plus-maze and light-dark box tests. The residence time in the closed arm increased with NP dose (4, 40 mg/kg) and exposure time (3 and 6 months) (P < 0.05). The hippocampal neurons in the medium dose (M-NP, 4 mg/kg) and high dose (H-NP, 40 mg/kg) groups showed disorderly arrangement, cell swelling, and nuclear pyknosis/necrosis. The protein/mRNA expressions of BDNF/TrkB/CREB in the H-NP group decreased, and the decrease was more significant at 6 months (P < 0.05). Both, NP exposure and BDNF knockdown, increase the number of apoptotic cells (P ＜0.001). NP downregulated the proteins/mRNA expressions of BDNF/TrkB/CREB, and the trend was consistent with the BDNF silence group. Chronic exposure to NP could induce anxiety-like behavior in rats and reduce the expression of key proteins/genes in the BDNF/TrkB/CREB signaling network.

Relationship between exposure of alkylphenols in serum of pregnant women during early pregnancy and adverse birth outcomes

Alkylphenols are a type of endocrine disruptors, which are commonly found in personal care products, food, and water and are more harmful to the human body. To investigate the relationship between exposure of alkylphenols in serum of pregnant women during early pregnancy and adverse birth outcomes, a total of 2035 healthy pregnant women and their neonates were recruited in the birth cohort of Zhuang nationality in Guangxi from 2015 to 2018. The peripheral venous blood samples were collected from pregnant women in early pregnancy; the concentrations of nonylphenol (NP), 4-nonylphenol (4-N-NP), 4-tert-octylphenol (4-T-OP), and 4-n-octylphenol (4-N-OP) in serum were detected by ultra-performance liquid performance chromatography-tandem mass spectrometry (UPLC-MS). Binary logistic regression showed that NP [OR = 1.40 (95% CI: 1.00, 1.94)] was positively associated with preterm birth. Restricted cubic spline analyses showed that logNP and log4-T-OP had non-linearity associations with preterm birth (logNP: P_overall = 0.006, P_non-linear = 0.003; log4-T-OP: P_overall = 0.004, P_non-linear = 0.002). Multiple linear regression analysis showed that maternal serum concentration of NP was negatively associated with birth weight of perinatal infants (β = -14.68, 95% CI: -29.18, -0.19), which may be sensitive in male neonates (β = -26.18, 95% CI: -47.33, -5.02). The findings demonstrate that nonylphenol is a risk factor of preterm birth, and nonylphenol is negatively associated with the birth weight in male infants.

Developmental immunotoxicity and its potential gender differences of perinatal exposure to 4-nonylphenol on offspring rats: JAK-STAT signaling pathway involved

The aim of our study was to explore the developmental immunotoxicity (DIT) and its potential gender differences of perinatal exposure to 4-nonylphenol (4-NP), which was significant for the risk assessment of 4-NP exposure to fetuses and infants. Wistar pregnant rats were given the National Institution of Health (NIH)- 31 modified feed containing 0, 10, 100 and 500 mg/kg 4-NP from the gestation day (GD) 6 to the postnatal day (PND) 21. At PND21, the offspring rats were randomly selected to detect developmental immunotoxicity related indicators. Results suggested that high-dose 4-NP perinatal exposure caused growth retardation in infancy of male offspring rats, which was not obvious in female offspring rats. Also, 4-NP perinatal exposure induced DIT (mainly manifested as immunosuppression) with potential gender differences, including decreased weight of immune organs, suppressed immune function, decreased ratio of transforming growth factor (TGF)-β/interleukin (IL)- 17A, increased ratio of T helper (Th) 17/regulatory T (Treg) cells et al. In addition, exploration of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway showed that JAK-STAT pathway mediated the leftward of Th17/Treg cells balance. Furthermore, the DIT to female offspring rats was more sensitive than to the males, which may be related to the differences of biological processes involved and needed to be further explored.

Ecotoxicological impacts caused by high demand surfactants in Latin America and a technological and innovative perspective for their substitution

Nowadays, water pollution represents a great concern due to population growth, industrialization, and urbanization. Every day hazardous chemical products for humans and aquatic organisms are disposed of arbitrarily from homes and industries. Even though detergents are considered an essential market, there is evidence of environmental impacts caused by surfactants like nonylphenol ethoxylate (NPE) and linear alkylbenzene sulfonates (LAS). Regulations about maximum allowable concentrations in sewage, surface water, and drinking water are scarce or null, mostly in developing countries like Latin American countries. Therefore, this review explores these two common toxic surfactants (NPE and LAS) and proposes a technological, innovative, and ecological perspective on detergents. Also, it establishes a starting point for industries to minimize adverse effects on humans and environmental health caused by these compounds.

High-fat diet accelerate hepatic fatty acids synthesis in offspring male rats induced by perinatal exposure to nonylphenol

BACKGROUND

Low dose of NP exposure can alter adipose tissue formation, and the intake of high-fat diet (HFD) can also lead to the fatty liver disease. We investigated the combined effect of NP and HFD on the first offspring of rats, and whether this effect can be passed to the next generation and the possible mechanisms involved.

METHODS

Pregnant rats had access to be treated with 5 μg/kg/day NP and normal diet. The first generation rats were given normal diet and HFD on postnatal day 21, respectively. Then the second generation rats started to only receive normal diet without NP or HFD. Body weight, organ coefficient of liver tissues, lipid profile, biochemical indexes and the expression of genes involved in lipid metabolism, as well as liver histopathology were investigated in male offspring of rats.

RESULTS

NP and HFD interaction had significant effect on the birth weight, body weight and liver tissue organ coefficient of first generation male rats. And HFD aggravated abnormal lipid metabolism, even abnormal liver function and liver histopathological damage of first generation male rats produced by the NP. And this effect can be passed on to the second generation rats. HFD also accelerated the mRNA level of fatty acid synthesis genes such as Lpl, Fas, Srebp-1 and Ppar-γ of first generation rats induced by perinatal exposure to NP, even passed on to the second generation of male rats. NP and HFD resulted in synergistical decrease of the protein expression level of ERα in liver tissue in F2 male rats.

CONCLUSION

HFD and NP synergistically accelerated synthesis of fatty acids in liver of male offspring rats through reducing the expression of ERα, which induced abnormal lipid metabolism, abnormal liver function and hepatic steatosis. Moreover, all of these damage passed on to the next generation rats.

Impact of Nonylphenols and Polyhalogenated Compounds in Follicular Fluid on the Outcome of Intracytoplasmic Sperm Injection

Endocrine-disrupting chemicals (EDCs) interfere with the mammalian hormone system and alter its endo- and paracrine regulation. The goal of the present study was to examine the presence of 14 EDCs, including the technical mixture of nonylphenols and Mirex, in human follicular fluid (FF) and to find a potential correlation between endocrine active substances and a possible impact on female fertility. Furthermore, potential sources of EDC exposition regarding patients' lifestyle and socioeconomic factors were investigated. Human FF was collected from a total of 210 women undergoing intracytoplasmic sperm injection-treatment cycles because of male subfertility. The presence of EDCs was analyzed using gas chromatography coupled with mass spectrometry. Thirteen of the 14 investigated EDCs were present in every FF sample; compounds with the highest concentrations in FF were nonylphenol and Mirex. Nearly all kinds of EDCs led to significantly reduced maturation and fertilization rate. No significant influence of EDC concentration on the clinical pregnancy rate was observed for neither of the analyzed EDCs. Patients who obtained their clothes and textiles at fashion discounters displayed a higher amount of EDCs in their FF. In contrast, patients' residential area, source of food products, and nicotine or caffeine consumed were not associated with EDC accumulation. Clinicaltrials.gov NCT01385605 (11 July 2011).

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.

Nonylphenol Induces Apoptosis through ROS/JNK Signaling in a Spermatogonia Cell Line

Nonylphenol (NP) is an endocrine-disruptor chemical that negatively affects reproductive health. Testes exposure to NP results in testicular structure disruption and a reduction in testicular size and testosterone levels. However, the effects of NP on spermatogonia in testes have not been fully elucidated. In this study, the molecular mechanisms of NP in GC-1 spermatogonia (spg) cells were investigated. We found that cell viability significantly decreased and apoptosis increased in a dose-dependent manner when GC-1 spg cells were exposed to NP. Furthermore, the expression levels of the pro-apoptotic proteins increased, whereas anti-apoptosis markers decreased in NP-exposed GC-1 spg cells. We also found that NP increased reactive oxygen species (ROS) generation, suggesting that ROS-induced activation of the MAPK signaling pathway is the molecular mechanism of NP-induced apoptosis in GC-1 spg cells. Thus, NP could induce c-Jun phosphorylation; dose-dependent expression of JNK, MKK4, p53, and p38; and the subsequent inhibition of ERK1/2 and MEK1/2 phosphorylation. The genes involved in apoptosis and JNK signaling were also upregulated in GC-1 spg cells treated with NP compared to those in the controls. Our findings suggest that NP induces apoptosis through ROS/JNK signaling in GC-1 spg cells.

Toxic effects of perinatal maternal exposure to nonylphenol on lung inflammation in male offspring rats

The incidence of asthma and its related allergic diseases has increased dramatically over the last decade. Asthma is a complex disease caused by genetic and environmental factors. Nonylphenol (NP), a typical endocrine disrupting chemical (EDC), is a major current focus in asthma research. Pregnant Sprague-Dawley rats (n = 8-10 per group) were given a consecutive daily dose of NP (25, 50, or 100 mg/kg/day) or an equivalent volume of vehicle by gavage from gestational day 7 until postnatal day (PND) 21. Exposure to 100 mg/kg NP increased the body mass of the offspring on PND 43. Perinatal exposure to NP in maternal rats led to a dose-dependent increase of NP level in the lung tissue of the offspring. The numbers of lymphocytes and neutrophils in bronchoalveolar lavage fluid were significantly higher in the 100 mg/kg NP group than those in the control. Histopathological examination of the lung showed that exposure to high dose NP resulted in a slightly thickened bronchiolar smooth muscles with inflammatory cell infiltration. In the cytoplasm of type II epithelial cells, osmiophilic lamellar bodies were observed, with emptied lamellar bodies. NP significantly increased the expressions of high mobility group box 1 protein (HMGB1) mRNA and nuclear factor κB (NF-κB) mRNA in the lung tissue of the offspring in a dose dependent manner. Similarly, the expressions of HMGB1, NF-κBp65 and estrogen receptor-β (ER-β) proteins increased with an increase of NP dose. NP content was positively correlated with the expressions of HMGB1 and NF-κB mRNA as well as HMGB1, NF-κBp65, and ER-β proteins in the lung tissue of offspring. Perinatal exposure to NP from the maternal rats might induce airway inflammation in the offspring, which may be due to NP-induced infiltration of inflammatory cells into the airway, and pathological alterations in airway structure as well as abnormal expression patterns of inflammation-related genes, proteins (including HMGB1 and NF-κB) and estrogen receptor β.

Bayesian inference of nonylphenol exposure for assessing human dietary risk

Nonylphenols (NPs) are endocrine-disrupting compounds commonly found in the environment and a number of food products. In this study, we constructed a probabilistic risk framework incorporating a Bayesian inference of exposure level in foodstuffs in conjunction with effect analysis of reproduction and renal disease. Our objective was to contrast the risk of dietary exposure to NPs among individuals in various age groups, with a particular focus on fertile females. In this study, seafood presented relatively high NP concentrations; however, seafood accounts for only a small proportion of the total food intake of most individuals. Rice was shown to make the largest contribution to NP daily intake among males and females in most age groups. Chicken made the largest contribution in the 12-16 and 16-18 year age groups. The mean average daily dose of NPs tended to decrease with age, regardless of gender. The estimated distribution of hazard quotients of <1 in all groups means that the risk of reproductive or renal abnormalities due to dietary exposure to NPs is negligible within most of the Taiwanese population. Nonetheless, preschoolers (3-6-year-olds) appear to be more vulnerable to NPs than do individuals in other age groups. There has been growing concern among researchers concerning the neurotoxic effects of NPs on offspring via maternal exposure. We recommend conducting a comprehensive assessment of exposure to NPs via multiple exposure routes, particularly among fertile women and preschoolers.

Exposure to nonylphenol in early life increases pro-inflammatory cytokines in the prefrontal cortex: Involvement of gut-brain communication

A growing body of evidence indicates that exposure to nonylphenol (NP), a typical persistent organic pollutant (POP), in early life results in the impairment of the central nervous system (CNS), but the underlying mechanism still remains to be elucidated. High levels of pro-inflammatory cytokines in the brain have been implicated in the CNS damages. The animal model of exposure to NP in early life was established by maternal gavage during the pregnancy and lactation in the present study. We found that exposure to NP in early life increased the levels of pro-inflammatory cytokines in the rat prefrontal cortex. Interestingly, the levels of pro-inflammatory cytokines in the intestine as well as in the serum were also increased by NP exposure. Furthermore, the increased permeability of intestinal barrier and blood-brain barrier (BBB), two critical barriers in the gut to brain communication, was observed in the rats exposed to NP in early lives. The decreased expression of zonula occludens-1 (ZO-1) and claudin-1 (CLDN-1), tight junction proteins (TJs) that responsible for maintaining the permeability of intestinal barrier and BBB, was found, which may underlie these increases in permeability. Taken together, these results suggested that the disturbed gut-brain communication may contribute to the increased levels of pro-inflammatory cytokines in the prefrontal cortex caused by NP exposure in early life.

Differential Toxicity of Alkylphenols in JEG-3 Human Placental Cells: Alteration of P450 Aromatase and Cell Lipid Composition

Alkylphenols (APs) are a diverse class of chemicals that can cross the placental barrier and interfere with embryonic and fetal development. This work investigates the comparative toxicity, ability to inhibit aromatase activity, and to alter the lipid composition of 10 alkylphenols in the human placenta choriocarcinoma cell line JEG-3. Among the selected APs, 4-dodecylphenol (DP), 4-heptylphenol (HP), and 4-cumylphenol (CP) showed the highest cytotoxicity (EC50: 18-65 µM). Aromatase inhibition was closely related to the hydrophobicity of APs. HP significantly induced the generation of reactive oxygen species (ROS) (43-fold), inhibited placental aromatase activity (IC50: 41 µM), and induced a general dose-dependent depletion of polyunsaturated lipids (10-20 µM), which were attributed to high levels of oxidative stress. In contrast, 2,4,6-tri-tert-butylphenol (TTBP) significantly induced the intracellular accumulation of triacylglycerides (TGs), whereas DP increased the synthesis of phosphatidylcholines (PCs) and TGs at the expense of diacylglycerides (DGs). Overall, this study evidences the different modes of action of alkylphenols in human placental JEG-3 cells, describes differential lipidomic fingerprints, and highlights DP, HP, CP, and TTBP as the ones that caused the most harmful effects.

The environmental hormone nonylphenol interferes with the therapeutic effects of G protein-coupled estrogen receptor specific agonist G-1 on murine allergic rhinitis

The G protein-coupled estrogen receptor (GPER) specific agonist G-1 has therapeutic effects in patients with allergic diseases, but any role for G-1 as a therapy for inflammation associated with allergic rhinitis (AR) remains unclear. The structure of the environmental hormone nonylphenol (NP) is very similar to that of estrogen; it binds to the estrogen receptor to produce estrogen-like effects and thus may also bind to the membrane GPER. We explored whether NP administration would reduce the effects of G-1 on AR, the interactions between the two materials, and their mechanisms of action using a murine model of AR. Mice were randomly assigned into control, AR, G-1, and G-1 + NP groups (n = 10/group). AR nasal symptoms were scored. Eosinophils in nasal mucosa were counted after staining with hematoxylin and eosin. Serum ovalbumin (OVA)-specific IgE was determined by ELISA. The proportions of splenic Th1, Th2, and Treg cells were determined by flow cytometry. The expression of transcription factors unique to Th1, Th2, Treg cells and cytokine levels in nasal mucosa were evaluated by real-time PCR and cytometric bead arrays. AR nasal symptoms, including sneezing, nasal scratching, eosinophil infiltration of nasal mucosa, and serum IgE, were reduced in G-1 group. After injection, Th2 cells proportions, Th2-immune response-related cytokines (IL-4, IL-5, and IL-13), and a Th2 cell-specific transcription factor (GATA-3) were significantly decreased in G-1 group. Treg immune response was enhanced (as reflected by Treg cell, IL-10, and Foxp3 levels). The levels of all of these were significantly increased after adding NP, and the Treg immune response was significantly decreased. These results indicate that G-1 attenuated the nasal symptoms, serum OVA-specific IgE, and Th2 cell immune response, whereas it enhanced Treg immune response, in mice with AR. Adding NP weakened these therapeutic effects.

Removal and biotransformation of 4-nonylphenol by Arthrospira maxima and Chlorella vulgaris consortium

4-Nonylphenol (4-NP) is an anthropogenic contaminant found in different environmental matrices that has an effect over the biotic and abiotic factors within the environment. Bioremediation by microorganisms can be used as a potential treatment to remove this pollutant. In this work, a consortium of two microorganisms, Arthrospira maxima and Chlorella vulgaris, was employed to remove 4-NP from water. The parameters analyzed included cell growth, removal of 4-NP, and 4-NP remnant in the biomass. In addition, the metabolites produced in the process by this consortium were identified. It was found that C. vulgaris is more resistant to 4-NP than A. maxima (cell growth inhibition by 4-NP of 99%). The consortium used in this study had an IC₅₀ greater than any strain of microalgae or cyanobacteria reported for 4-NP removal (9.29 mg/L) and reduced up to 96% of 4-NP in water in the first 48 h of culture. It was also observed that there is a bio-transformation of 4-NP, comparable with the process carried out by another bacterium, in which three similar metabolites were found (4-(1-methyl-octyl)-4-hydroxy-cyclohex-2-enone, 4-nonyl-4-hydroxy-ciclohexa-2,5-dienone and 4-nonyl-4-hydroxy- ciclohex-2-enone) and one that is similar to plant metabolism (4-nonyl-(1-methyl,6,8-metoxy)-hydroxybenzene). These results indicate that microalgae and cyanobacteria consortium can be used to remove 4-NP from water.

Simultaneous determination of parabens, bisphenols and alkylphenols in human placenta by ultra-high performance liquid chromatography-tandem mass spectrometry

This study presents de development and validation of an ultra- high performance liquid chromatography - tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of four parabens (methyl-, ethyl-, propyl-, and butyl-paraben (MeP, EtP, PrP, BuP), four bisphenols (BP) (BPA, BPB, BPF, and BPS) and two alkylphenols (nonyl phenol (NP) and tert-octylphenol (OP) in human placenta samples. After a short sample preparation time the extracts are analysed by UHPLC-MS/MS using negative electrospray ionization. Labeled internal standards and matrix-matched calibration are used for quantification of the compounds. The method was validated according FDA guideline for bio analytical methods using spiked samples at three concentration levels (0.5-5 and 25 ng g^-1). The parameters accuracy and precision fulfill the criteria. Calibration curves are linear between 0.5 and 50 ng ^-1. The limits of detection and quantification are in the range of 0.1-0.3 ng g^-1 and 0.2-0.7 ng g^-1, respectively. The applicability of the method was demonstrated on 71 human placenta samples from a Belgian cohort. The detection frequency was highest for OP (95%), EtP (86%), BPA (49%) and BPS (44%). Among the quantified compounds the highest quantification frequency was observed for OP (85%), EtP (65%) and BPA (25%). The concentrations of parabens ranged from 0.5 to 7.1 ng g^-1 for MeP, from 0.5 to 4.5 ng g^-1 for EtP and from 0.5 to 9.1 ng g^-1 for PrP. The levels of bisphenols ranged from 0.5 to 3.9 ng g^-1 for BPA, from 0.6 to 2.1 ng g^-1 for BPF and from 0.8 to 1.3 ng g^-1 for BPS. BPB and NP were not detected and OP levels ranged from 0.5 to 3.7 ng g g^-1. The results demonstrate that the developed analytical method is very sensitive and that levels of several compounds with known /suspected endocrine disrupting properties could be detected or quantified in human placenta samples. The results therefore suggest that fetal exposure to these compounds occurs. The method will be useful for studies to evaluate the health effects associated with this prenatal exposure.

Nonylphenol can aggravate allergic rhinitis in a murine model by regulating important Th cell subtypes and their associated cytokines

Nonylphenol (NP) is a widely distributed, toxic endocrine-disrupting chemical exhibiting estrogenic activity. However, its effect on allergic rhinitis (AR) remains unclear. In this study, the effects of NP on a murine model of AR were investigated. Mice were divided into ovalbumin (OVA), NP, and control groups. OVA was used for sensitization and challenge. Mice in the NP group were administered NP during the sensitization period. Allergic nasal symptoms and eosinophil counts in nasal mucosa were measured. Serum levels of OVA-specific IgE were determined by enzyme-linked immunosorbent assay. The mRNA levels of transcription factors of Th cells were determined with real-time polymerase chain reaction. Th cell subtypes and Treg numbers were counted with the aid of multi-color flow cytometry. Cytokine concentrations in nasal mucosa were determined using the cytometric bead array method. Subcutaneous injection of NP into mice exhibiting AR enhanced not only the nasal allergic symptoms, but also eosinophil infiltration and OVA-specific IgE. Moreover, NP upregulated IL-4, IL-5, IL-13, IL-9, IL-6 and IL-17, and downregulated IL-10, in the AR mouse model; IFN-γ and IL-23 were not affected. Transcription factors and Th cell percentages were evaluated to determine whether NP regulates Th cell subtypes in an AR mouse model. GATA3, PU.1, and RORγt levels were significantly increased, but FoxP3 and Helios were decreased. In addition, Th2, Th9, and Th17 subtype percentages significantly increased, and Treg cell percentages decreased, in NP administration groups; the percentage of Th1 subtypes was not affected. NP enhanced allergic inflammation in the AR mouse model through upregulation of Th2, Th9, and Th17 responses and negative regulation of Treg responses. These results suggest that NP may be trigger AR.

Alkylphenolic compounds and risk of breast and prostate cancer in the MCC-Spain study

BACKGROUND

Alkylphenolic compounds are chemicals with endocrine disrupting properties that have been widely used in industry with important changes in their usage over time. Few epidemiologic studies have evaluated the effect of alkylphenolic compounds on human health.

OBJECTIVES

We investigated whether occupational exposure to alkylphenolic compounds is associated with breast and prostate cancer.

METHODS

We carried out a population-based case-control study including 1513 incident cases of breast cancer, 1095 of prostate cancer, and 3055 controls, frequency matched by sex, age and region. Occupational exposure to alkylphenolic compounds was estimated using a recently developed job-exposure matrix, which considered different scenarios of exposure and different subtypes of alkylphenolic compounds.

RESULTS

History of occupational exposure to alkylphenolic compounds was modestly associated with breast cancer (OR = 1.23; 95% CI = 1.01-1.48). Within the different scenarios, the occupational use of domestic tensioactives was positively associated with breast cancer (OR = 1.28; 95% CI = 1.02-1.60), while occupational exposure in other scenarios showed mostly a suggestion of a similar positive associations. Exposure to nonylphenol ethoxylates was positively associated with breast cancer (OR = 1.21; 95% CI = 1.00-1.47), while exposure to other compounds was uncommon. In general, we did not observe associations between alkylphenolic compounds and prostate cancer, except for a positive association among men occupationally exposed to cosmetic, hair and personal hygiene products.

CONCLUSIONS

Our findings suggest a modest association between breast cancer risk and occupational exposure to alkylphenolic compounds, and no associations between these compounds and prostate cancer risk. These findings warrant further corroboration in other studies.

Interactive effects of nonylphenol and bisphenol A exposure with oxidative stress on fetal reproductive indices

Nonylphenol (NP) and/or bisphenol A (BPA) may have reproductive effects. Although the mechanisms of action remain unclear, steroid hormones biosynthesis, hypothalamus pituitary adrenal axis activity, oxidative stress, and crosstalk interaction of NP and BPA mixture and its pathways may play a contributory role. This cross-sectional study examined whether the interactive effects of NP/BPA and oxidative stress biomarkers played a role in reproductive indices (penis length and anogenital distance (AGD)) in 244 mother-fetus pairs. Four biomarkers of oxidative stress, (8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-nitroguanine (8-NO₂Gua), 8-iso-prostaglandin F_2α (8-isoPF_2α), and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA)) were simultaneously analyzed using the high-performance liquid chromatography-electrospray ionization tandem mass spectrometry method. No significant associations were found between reproductive indices and NP/BPA or oxidative stress biomarkers. Maternal exposure to a mixture of NP and BPA may enhance 8-OHdG. Interactive effects were found in the high 8-isoPF_2α group, and prenatal NP exposure was inversely associated with penis length (β = -3.68 mm; p = 0.01). Similar results were noted among boys who were born to mothers in the high 8-isoPF_2α group, in which BPA was inversely associated with penis length (β = -4.43 mm; p = 0.005). Our findings suggest important implications for prenatal exposure to oxidative stress, as evidenced by the 8-isoPF2α level. Thus, NP and BPA may interact to shape fetal reproductive tract development, particularly in boys. The interactive effects of NP/BPA, oxidative stress, and reproductive indices should be considered.

Maternal transfer of phenol derivatives in the Baltic grey seal Halichoerus grypus grypus

Studies of circulating levels in difference sex and age classes, and maternal transfer of bisphenol A, 4-tert-octylphenol and 4- nonylphenol in the Baltic grey seal were performed from 2014-2017. Blood was collected from long-term captive adult males, pregnant females and pups. Milk was collected from nursing females. The aim of this study was not only to determine the concentrations of phenol derivatives, i.e. bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP), but also to try to evaluate the transfer of these compounds to the next generation in the final stage of foetal life and in the first few weeks of life in juvenile marine mammals. The measurements were carried out using high performance liquid chromatography. The obtained data show that all phenol derivatives are present in the blood of males, females and pups (range <0.07-101 ng·cm^-3) and in female milk (range <0.1-406.3 ng·cm^-3). The main source of phenol derivatives in organisms is food exposure. Gender, age, or number of births were not observed to have a significant effect on changes in phenol derivative levels in seal blood within the breeding group. In the prenatal stage of life, a small amount of BPA and alkylphenols was passed on to the offspring through the placenta. In the blood of the offspring the concentration of these compounds exceeded the concentration in the mother's blood 1.5-fold. During nursing, females detoxified their systems. Level of phenol derivatives in the pups blood increased linearly with its increasing concentrations in the mother's milk. On the other hand, the seafood diet which started after the physiological fasting stage of the pup, stabilised the levels of phenol derivatives below 10 ng ∙ cm^-3.

An integrated modelling framework and a modified method for evaluating non-carcinogenic health risks from nonylphenol-contaminated food consumption in Long An, Vietnam

This study proposed an integrated modelling framework and a modified method for evaluating non-carcinogenic health risks from nonylphenol (NP)-contaminated food consumption. First, a fugacity-based multimedia model and a food web bioaccumulation model were adopted to predict the distribution of NP in the Can Giuoc river and the bioaccumulative concentrations in biota. Next, local people's exposure to NP was quantified using the accumulative concentrations and the data of fishery products intake from a questionnaire survey distributed among 203 local people. Then, human health risk was evaluated in terms of fishery products intake and intake frequency which were each derived from the same survey. The study revealed that human health risk would exist, although the obtained bioaccumulation factors for the consumed organisms were lower than the bioaccumulation criteria. Consuming 141 g or more per serving of riverine food products resulted in an average NP intake exceeding 0.005 mg/kg of body weight per day among 45-73% of the local adults, of whom pregnant women or young and potential mothers accounted for 10-21%. Seventy-nine percent was the highest rate of the population to be at risk under medium river flow rate when food-intake amount and intake frequency were taken into account. Ingesting 70 g per serving of more contaminated species, such as whiteleg shrimp and small fish, less frequently could lead to less risk exposure than ingesting 267 g per serving of less contaminated species, such as sand goby and climbing pearch, more frequently. By coupling food intake with intake frequency, the modified method enables the studying of human health risk from NP-contaminated food consumption to be conducted with more care, and so benefits risk communication at local level.

Concurrent exposures to nonylphenol, bisphenol A, phthalates, and organophosphate pesticides on birth outcomes: A cohort study in Taipei, Taiwan

Prenatal exposure to phenols, phthalates (PAEs), and organophosphate (OP) pesticides may increase the risk of abnormal birth outcomes. However, many previous studies have examined exposure to a limited number of chemical classes or exposure profiles limited to a specific stage of pregnancy. This study aims to characterize the concurrent exposure scenario throughout pregnancy by simultaneously monitoring internal doses of several endocrine-disrupting compounds (EDCs), including 2 phenols (nonylphenol (NP) and bisphenol A (BPA)), 9 PAEs, and 6 OP pesticide metabolites and to assess the relationships between concurrent exposure to EDCs and infant birth weight, length, and head and chest circumference. One hundred and sixty two women provided three spot urine samples at approximately 11 and 26weeks gestation and at delivery. We applied multivariable linear regression and ridge regression models to estimate the effects of separate and correlated exposures. Multivariable linear regression models revealed that women with short birth-length infants had significantly higher urinary second-trimester NP levels (50th percentile, 5.03μg/g creatinine) (β=-0.47cm; 95% CI=-0.93 to -0.01). Similarly significant relationships were observed between second-trimester mono-methyl phthalate (MMP) exposure and short birth length, second-trimester ΣPAEs and short birth length, second-trimester ΣPAEs exposure and reduced head and chest circumference, second-trimester diethylphosphate (DEP) exposure and reduced birth weight and length, and second-trimester ΣDEPs exposure and short birth length. Women with urinary BPA above the 75th percentile or ΣPAEs levels above the 50th percentile in the third trimester had infants with significantly reduced head circumference. These observations suggest that the second trimester may be the critical stage of susceptibility for fetal development. In ridge regression models, for which women with fewer measures for exposure to NP, BPA, MMP, ΣPAEs, DEP and ΣDEPs simultaneously were available, no relationships were found with infant size at birth. Additional studies with larger sample sizes are warranted.

Transfer of mercury and phenol derivatives across the placenta of Baltic grey seals (Halichoerus grypus grypus)

The placenta is an intermediary organ between the female and the developing foetus. Some chemical substances, including the most harmful ones, exhibit the ability to accumulate in or penetrate through the placenta. The aim of the study was to determine the role of the placenta of the Baltic grey seal (Halichoerus grypus grypus) in the transfer of endocrine disrupting compounds (EDCs) - (bisphenol A, 4-tert- octylphenol, 4- nonylphenol), as well as total and organic mercury. 30 placentas were collected from grey seals pupping under human care at the Hel Marine Station in the years 2007-2016. The assays were conducted using the technique of high-preformance liquid chromatography (phenol derivatives) and atomic absorption spectrometry (mercury and selenium). A measurable level of EDCs was indicated in the placentas of grey seals. It was established that the inorganic Hg form was accumulated in the placenta, and that its concentrations were an order of magnitude higher than the concentrations of the organic form, which penetrated to the foetus. Similar observations were made for phenol derivatives - bisphenol A, 4-tert- octylphenol and 4-nonylphenol. For this compound group the placenta was a barrier, but the properties of phenol derivatives suggest the possibility of their penetration through this organ.

Prenatal Nonylphenol and Bisphenol A Exposures and Inflammation Are Determinants of Oxidative/Nitrative Stress: A Taiwanese Cohort Study

Prenatal exposure to nonylphenol (NP) and/or bisphenol A (BPA) has been reported to be associated with adverse birth outcomes; however, the underlying mechanisms remain unclear. The primary mechanism is endocrine disruption of the binding affinity for the estrogen receptor, but oxidative stress and inflammation might also play a contributory role. We aimed to investigate urinary NP and BPA levels in relation to biomarkers of oxidative/nitrative stress and inflammation and to explore whether changes in oxidative/nitrative stress are a function of prenatal exposure to NP/BPA and inflammation in 241 mother-fetus pairs. Third-trimester urinary biomarkers of oxidative/nitrative stress were simultaneously measured, including products of oxidatively and nitratively damaged DNA (8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-nitroguanine (8-NO₂Gua)) as well as products of lipid peroxidation (8-iso-prostaglandin F_2α (8-isoPF_2α) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA)). The antioxidant glutathione peroxidase (GPx) and inflammation biomarkers, including C-reactive protein (CRP) and a panel of cytokines (interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)), were analyzed in maternal and umbilical cord plasma samples. In adjusted models, we observed significant positive associations between NP exposure and 8-OHdG and 8-NO₂Gua levels, between BPA and 8-isoPF_2α levels, and between maternal CRP levels and HNE-MA levels. Additionally, BPA and TNF-α levels in cord blood were inversely associated with maternal and GPx levels in cord blood as well as maternal TNF-α levels were inversely associated with maternal GPx levels. These results support a role for exposure to NP and BPA and possibly inflammation in increasing oxidative/nitrative stress and decreasing antioxidant activity during pregnancy.

The endocrine disrupting alkylphenols and 4,4'-DDT interfere with estrogen conversion and clearance by mouse liver cytosol

Endocrine disrupting chemicals (EDCs) are ubiquitous compounds known for negative impacts on reproductive functions and for increasing cancer risk. EDCs are believed to cause the harmful effects in part through their inappropriate low-affinity binding to steroid receptors and other possible non-receptor mediated paradigms, however there is a need to further elucidate other mechanisms involving the direct and indirect impact of EDCs on reproductive functions. We examined the metabolism of 17β-estradiol (E2) and estrone (E1) by cell-free hepatic cytosol in the presence of alkylphenols (nonylphenol/NP and 4-tert-octylphenol/tOP), Dichlorodiphenyltrichloroethane (4,4'-DDT) and other EDCs. Tandem liquid chromatography mass spectrometry was utilized to quantitatively assess the impact of each EDC on estrogen clearance, inter-conversions and downstream metabolism by mouse liver cytosol. The results revealed that NP and tOP (0.1-3μg/mL) significantly reduced the hepatic cytosol clearance and biotransformation of estrogens with inclination for accumulating E2, the stronger estrogen form, than E1. Alkylphenols also caused up to a 34-fold increase in the E2/E1 ratio possibly by suppressing the hepatic E2→E1 conversion by 17β-hydroxysteroid dehydrogenase (17βHSD) types 2, 4 while displaying a weaker inhibition of E1→E2 conversion by type 1, 17βHSD. On the other hand, the pesticide 4,4'-DDT was a weaker inhibitor of clearance of estrogens by the cytosol preparations when compared to alkylphenols, whereas chemicals such as phthalates and atrazine were ineffective. Our data suggest that exposure to NP, tOP and DDT can indirectly increase the estrogenic load by suppressing the hepatic clearance of estrogens and by elevating the E2/1 ratio and could therefore increase the risk of reproductive lesions.

An Isomer-Specific Approach to Endocrine-Disrupting Nonylphenol in Infant Food

Nonylphenols (NPs) are persistent endocrine disruptors that are priority hazardous substances of the European Union Water Framework Directive. Their presence in the environment has caused growing concern regarding their impact on human health. Recent studies have shown that nonylphenol is ubiquitous in commercially available foodstuffs and is also present in human blood. The isomer distribution of 4-nonylphenol was analyzed by gas chromatography - mass spectrometry in 44 samples of infant food. Our study shows that the distribution of nonylphenol isomers is dependent on the foodstuff analyzed. Although some isomer groups prevail, different distributions are frequent. Variations are even found in the same food group. Nonylphenol is a complex mixture of isomers, and the estrogenic potentials of each of these isomers are very different. Consequently, to determine the potential toxicological impact of NP in food, an isomer-specific approach is necessary.

Nonylphenol induced apoptosis and autophagy involving the Akt/mTOR pathway in prepubertal Sprague-Dawley male rats in vivo and in vitro

This research explores the detrimental effect of nonylphenol (NP) to prepubertal Sprague-Dawley male rats in vivo and in vitro. Herein, forty-two 3-week-old rats were randomly divided into six groups, which were treated with NP (0, NAC, 25, 50, 100, 100+NACmg/kg/2d for 30 consecutive days) by intraperitoneal injection. NP induced a reduction in testosterone (15.58%, 17.23%, 13.38% in 25, 50, 100mg/kg group, respectively), triggered apoptosis related to oxidative stress, and disturbed mRNA and/or protein levels of PI3K, PTEN, PDK1, p-Akt, p-mTOR, p70S6K, caspase-3, LC3B. NP induced morphological abnormality in epididymal sperm (2.00-, 3.02-fold in 50, 100mg/kg group, respectively). Pretreatment with NAC, attenuated NP-induced ROS production; recovered testosterone in serum, and ameliorated toxic effect in epididymal sperm. Sertoli cells were isolated, purified, treated with NP (0, 10, 20, and 30μM) for 12h. NP disturbed mRNA and/or protein levels of caspase-3, cleave-caspase-3, LC3B involving the PI3K/Akt/mTOR pathway. It also decreased protein levels of ABP, FSHR, N-cadherin, transferrin, vimentin; disturbed the gene levels of all, but vimentin. Pretreatment with wortmannin, alleviated an NP-induced reduction in protein levels of PI3K and PTEN. In conclusion, excess NP exposure induces apoptosis and autophagy, causes reproductive lesions involving the PI3K/AKT/mTOR pathway both in vivo and in vitro. It also triggers oxidative stress and hormonal deficiency, reduces semen quality.

Attention Deficit/Hyperactivity Disorder and Urinary Nonylphenol Levels: A Case-Control Study in Taiwanese Children

Objective

Nonylphenol (NP) belongs to the family of endocrine disruptors, and it is widely used in industrial applications and is ubiquitous in daily foods. Animal studies have suggested that NP exposure might promote motor hyperactivity, likely by causing deficits in dopaminergic neurons. However, research assessing NP exposure and epidemiology studies on human populations are limited. The aim of this study was to explore the association between child NP exposure and ADHD while considering particular covariants, such as lead levels and dopamine-related gene variations.

Methods

A case-control study was conducted on patients with clinically diagnosed ADHD; the Swanson, Nolan and Pelham, Fourth Revision (SNAP-IV) questionnaire was used to identify normal controls aged 4–15 years. Participants were examined for urinary NP concentrations, blood lead levels, and select single-nucleotide polymorphisms of two dopamine-related genes (D4 dopamine receptor, DRD4, and dopamine transporter, DAT1). Socio-demographic variables, maternal lifestyle factors during pregnancy and family medical history were obtained using a questionnaire.

Results

A total of 97 children with doctor-diagnosed ADHD and 110 normal controls were enrolled. The blood lead levels in both groups were similar (1.57±0.73 vs. 1.73±0.77 μg/dL, p = 0.15). No significant difference in urinary NP concentration was found between the children with ADHD and the control subjects (4.52±3.22 μg/g cr. vs. 4.64±2.95 μg/g cr., p = 0.43). ADHD was significantly more prevalent among males in this study (male to female ratio: 5:1 for the ADHD group and 1.3:1 for the control group, p<0.01). The analysis was repeated after excluding the females, but this had no effect on the association between NP and ADHD. The regression model, including or excluding females, indicated no increased odds of having ADHD in the context of NP exposure after adjusting for covariants.

Conclusion

This study indicated that NP exposure might not promote ADHD in children, even though children in Taiwan had relatively high levels of NP compared to those reported previously and those in developed nations.

Occurrence and Maternal Transfer of Chlorinated Bisphenol A and Nonylphenol in Pregnant Women and Their Matching Embryos

Prenatal exposure has recently raised concerns over the health risks of endocrine disruptors; however, little is known about their extent and the mechanisms of maternal transfer in the embryo stage. In this study, bisphenol A (BPA), nonylphenol (NP), and their six chlorinated derivatives were quantified in decidua samples from 25 pregnant women and their matching embryos, which were collected as chorionic villi samples. Monochloro-BPA (MCBPA), dichloro-BPA (DCBPA), monochloro-NP (MCNP), and dichloro-NP (DCNP) were detected in over 70% of the decidua or chorionic villi samples, while BPA, NP, trichloro-BPA (TCBPA), and tetrachloro-BPA (TeCBPA) were detected in less than half. The geometric mean (GM) concentrations of MCBPA, DCBPA, NP, MCNP, and DCNP in chorionic villi samples were 0.13, 0.17, 5.33, 4.52, and 2.44 ng/g dw, respectively, higher than those in maternal decidua samples, which were 0.10, 0.12, 3.27, 1.85, and 0.74 ng/g dw, respectively, while the GM concentration of BPA was lower in chorionic villi samples (0.09 ng/g dw) than in maternal decidua (0.10 ng/g dw). The ratios of the average lipid-normalized concentrations of chemicals in chorionic villi to those in maternal decidua (EMR) were calculated to be 1.53 for MCNP and 2.38 for DCNP, while those of BPA, MCBPA, DCBPA, and NP were lower than 1 (0.39-0.97). Such obvious difference in maternal transfer is probably due to their different affinities to plasma proteins, as exemplified by the correlation between EMR and the binding affinities to T4 transport proteins (TTR). This is the first report on the occurrence and maternal transfer of chlorinated derivatives of BPA and NP in human embryos and decidua.

Prenatal nonylphenol exposure, oxidative and nitrative stress, and birth outcomes: A cohort study in Taiwan

Data concerning the effects of prenatal exposures to nonylphenol (NP) and oxidative stress on neonatal birth outcomes from human studies are limited. A total of 146 pregnant women were studied (1) to investigate the association between prenatal NP exposure and maternal oxidative/nitrative stress biomarkers of DNA damage (8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-nitroguanine (8-NO2Gua)) and lipid peroxidation (8-iso-prostaglandin F2α (8-isoPF2α), 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA)) and (2) to explore the associations among oxidative stress biomarkers, NP exposure, and neonatal birth outcomes, including gestational age, birth weight, length, Ponderal index, and head and chest circumferences. NP significantly increased the 8-OHdG and 8-NO2Gua levels. All infants born to mothers with urinary 8-OHdG levels above the median exhibited a significantly shorter gestational duration (Badjusted = -4.72 days; 95% CI: -8.08 to -1.36 days). No clear association was found between NP levels and birth outcomes. Prenatal 8-OHdG levels might be a novel biomarker for monitoring fetal health related to NP exposure.

Low concentrations of Bisphenol A and para-Nonylphenol affect extravillous pathway of human trophoblast cells

Bisphenol A (BPA) and para-Nonylphenol (p-NP) are chemicals of industrial origin which may influence human reproductive health. The effects of these substances in the prenatal life is an important topic that is receiving greater attention in the developed countries. In this study, human trophoblast cells HTR-8/SVneo were exposed to BPA and p-NP (1 × 10(-15), 1 × 10(-13), 1 × 10(-11), 1 × 10(-9) and 1 × 10(-7) M) and incubated for 24, 48 and/or 72 h then, examined for the main physiological processes which characterize the extravillous trophoblast. Cell proliferation showed no changes while the processes of cell migration and invasion were both reduced by BPA and p-NP. For each chemical, the activity was higher at lower concentrations with a maximum activity between 1 × 10(-13) and 1 × 10(-11) M (p < 0.05 for 1 × 10(-9) and p < 0.001 for 1 × 10(-11) M). Co-culture studies with human umbilical cord endothelial cells (HUVEC) revealed that trophoblast/endothelial interaction was significantly reduced by p-NP at 1 × 10(-11) M. Moreover, both chemicals were inducing differentiation of HTR-8/SVneo toward polyploidy by the process of endoreduplication. The estrogen-receptor antagonist ICI significantly reduced p-NP action, while it had no effect on BPA treated cells. In conclusion, p-NP and BPA act on trophoblast cells altering key physiological processes in placenta development. The exact mechanism of action of the chemicals in human trophoblast still needs to be clarified.