Phthalate metabolites in paired human serum and whole blood

Active binding mechanism to superoxide dismutase and toxicological implication for environmentally prevalent phthalates and their hydrolytic products: Coupling in vitro bioassay with molecular dynamics simulation

Phthalic acid esters (PAEs) are widely used as plasticizers to improve the flexibility and durability of plastics. However, their environmental presence poses risks by inducing oxidative stress and contributing to metabolic syndrome. Despite being linked to various diseases, the mechanisms by which PAEs disrupt antioxidant enzymes, particularly superoxide dismutase (SOD), are not well understood. This study investigated the molecular interactions between PAEs, their metabolites, and SOD using bioassays and theoretical simulations. The results showed that key metabolites, monophthalates (MAEs) and phthalic acid (PA), strongly inhibited SOD activity, with potency increasing as side chain length decreased. In contrast, PAEs caused minor changes in SOD activity. The inhibition resulted from tight binding of MAEs and PA to the residues in the enzyme's bottom cavity. PAEs and metabolites induced significant structural changes in the secondary structures, catalytic channel, and hydrogen bond network, destabilizing the protein and impairing its function. A strong correlation between SOD inhibition and Gibbs free binding energies at Arg141 was observed. Arg141 and allelic residues can serve as biomarkers for early warnings of oxidative stress. This study improves our understanding of oxidative stress mechanisms caused by PAEs and emphasizes the need for better risk management of phthalate exposure.

Multi-approach study on diethylhexyl phthalate and monoethylhexyl phthalate binding to lysozyme: In silico, bioactivity and surface plasmon resonance analyses

Diethylhexyl phthalate (DEHP) and its metabolite monoethylhexyl phthalate (MEHP) are recognized as endocrine disruptors with significant toxicological effects on various human physiological systems. While previous research has explored phthalate-protein interactions, there is a notable gap in studies focusing on the interaction between these endocrine disruptors and lysozyme (LZM), a critical component of the immune system. This study aimed to investigate the interactions of DEHP and MEHP with chicken egg white lysozyme (CEWLZM) using molecular docking, molecular dynamics simulations, bioactivity and surface plasmon resonance (SPR) analyses to evaluate the molecular mechanisms, binding affinity, kinetic properties and bioactivity effects of these interactions. Complementary insights from molecular docking and molecular dynamics simulations indicate that DEHP has a stronger binding affinity for CEWLZM than MEHP. This affinity value was corroborated by an intense hydrophobic and van der Waals interaction network especially maintained by the active residue Leu75 and Asp101-Ala107. Although MEHP did not exhibit a significant effect on enzyme activity in lysozyme bioactivity assay, DEHP inhibited lysozyme with an IC50 value of 453 µM. SPR analysis revealed that DEHP exhibits a significantly stronger binding affinity to CEWLZM compared to MEHP.

Bio-monitoring of endocrine disrupting chemicals in human serum: insights from a study in Central India

In recent years, the health impacts of phthalates and bisphenol-A (BPA) have garnered significant research attention due to their widespread use in consumer products and identification as endocrine disrupting chemicals (EDCs). Human exposure occurs through various pathways, including dietary intake, inhalation of dust, and dermal contact. This study initially aimed to analyze serum samples from 200 participants in Jabalpur city (Central India); however, samples from 173 individuals were ultimately analyzed to assess the occurrence, concentration patterns, and gender-related differences of six phthalates and BPA. Serum samples were collected, processed, and analyzed for EDC content using gas chromatography coupled with mass spectrometry. The findings highlighted differences in detection frequencies among genders and residential areas, shaped by environmental exposure variability, lifestyle variations, and gender-specific metabolic disparities. All the targeted analytes were detected with diethyl phthalate (DEP) having the highest mean concentration of 13.74 ± 6.2 ng/ml, followed by di(2-ethylhexyl) phthalate (DEHP) with mean value of 13.69 ± 99.82 ng/ml in human serum. Studies have linked DEP exposure endocrine disruption and reproductive abnormalities. Subsequent research endeavors should prioritize elucidating EDC sources, pathways, and health impacts, facilitating evidence-based policies to mitigate risks and ensure a healthier future.

Ti3C2Tx/Au NPs/PPy ternary heterostructure-based intra-capacitive self-powered sensor for DEHP detection

Phthalate esters, particularly di(2-ethylhexyl) phthalate (DEHP), are widely used plasticizers found in various consumer products, posing significant environmental and health risks due to their endocrine-disrupting effects. In this study, a novel enzyme-free intra-capacitive biofuel cell self-powered sensor (ICBFC-SPS) was developed. The ICBFC-SPS integrated a ternary heterostructure-based capacitive anode and a cathode with a sensing interface into a single-chamber electrolytic cell. The ternary heterostructure based on Ti3C2Tx MXene with ultra-small Au NPs and polypyrrole (PPy) NPs was prepared to provide the efficient glucose oxidation and robust electron production. Furthermore, the charge storage capacity was significantly enhanced through a synergistic combination of the double-layer capacitor mechanism of Ti3C2Tx and the pseudocapacitive behavior of PPy. Additionally, the intercalation of PPy NPs expanded the interlayer spacing, promoting electrolyte ion diffusion and charge transfer. The ICBFC-SPS demonstrated exceptional sensitivity with a linear detection range from 0.05 to 100000 ng/L and a detection limit of 9.51 pg/L for the sensitive and selective detection of DEHP in complex environmental and biological samples. The ICBFC-SPS addresses the limitations of traditional methods by providing a self-powered, highly sensitive, and portable platform for rapid, on-site DEHP detection. This work underscores the potential of self-powered sensors as transformative tools for real-time environmental monitoring and public health protection.

Dynamic assessment of phthalate exposure: Linking internal and external monitoring in diverse indoor environments

Phthalates (PAEs), as prevalent endocrine disruptors, are widely distributed in indoor environments and enter the human body through dermal contact, respiratory inhalation, and ingestion, subsequently participating in metabolic processes across various organs and tissues. Existing studies primarily focus on predicting regional exposure scenarios to assess internal or external exposures risks; however, limited studies have systematically examined the correlation and discrepancies between internal and external exposures. This study collected PAEs samples from three phases (gas, particle, and dust phases) across three representative indoor environments and conducted urinary biomonitoring of phthalate metabolites (mPAEs) among exposed populations. Results showed that PAEs concentrations in the gas phase (21.67 μg·m-3) and particle phase (2.38 μg·m-3) were significantly higher in laboratories than in dormitories and offices, whereas office desktops exhibited the highest dust phase concentration (312 μg·g-1). Urinary analysis revealed distinct metabolic profiles across populations: MBP was the dominant metabolite in office and dormitory groups (median: 19.3 ng·mL-1 and 10.4 ng·mL-1, respectively), while MMP prevailed in laboratory populations (median: 18.3 ng·mL-1). Seasonal variation analysis indicated that urinary mPAEs concentrations were 4.28 times higher in summer than in winter. Demographic analysis showed that mPAEs levels were higher in males, individuals with obesity, and those with frequent plastic use compared to females, individuals with normal BMI, and those with infrequent plastic use. Furthermore, external exposure estimated from ambient PAEs concentrations exceeded internal exposure derived from urinary mPAEs concentrations by 17.3 %. These findings provide critical insights into exposure pathway differentiation and risk assessment optimization for indoor PAEs contamination.

Molecular Mechanisms of Phthalate-Induced Hepatic Injury and Amelioration by Plant-Based Principles

Phthalates are the emerging environmental toxicants derived from phthalic acid and its constituents, which are moderately present in plastics and many personal care products. Phthalate exposure occurs through various environmental factors, including air, water, and soil, with absorption facilitated via ingestion, inhalation, and dermal contact. Upon exposure, phthalates become bioavailable within the biological systems and undergo biotransformation and detoxification processes in the liver. The physicochemical properties of phthalates indicate their lipophilicity, environmental persistence, and bioaccumulation potential, influencing their absorption, distribution, and hepatic biotransformation. The prolonged exposure to phthalates adversely influences the biological redox system by altering the levels of the enzymatic and non-enzymatic antioxidants, molecular signaling pathways, and causing hepatic pathogenesis. The strategies to combat phthalate-induced toxicity include avoiding exposure to these compounds and using plant-based bioactive molecules such as polyphenols, which possess therapeutic potential as antioxidants, suppress inflammatory cascades, prevent oxidative damage, and stabilize cellular integrity. This review presents a comprehensive and updated account of the chemical, biochemical, immunological, and toxicological properties of phthalates, along with novel plant-based therapeutic strategies to mitigate the phthalate-induced adverse effects on living systems.

Exposure to Multiple Endocrine-Disrupting Chemicals and Associations with Female Infertility: A Case-Control Study

Parabens (PBs) and their metabolites (MBs), triclocarban (TCC), triclosan (TCS), bisphenols (BPs), benzophenones (BzPs), and phthalate metabolites (mPAEs) are typical endocrine-disrupting chemicals (EDCs) used in industrial production and daily life. Studies have suggested that these EDCs affect the reproductive system and may cause infertility; however, epidemiological evidence linking EDC exposure to infertility is still lacking. Herein, a total of 302 serum samples from women of reproductive age were collected, and six categories of typical EDCs were analyzed. The results revealed that EDCs are ubiquitous in female serum. The geometric mean (GM) concentrations of ∑PBs, ∑MBs, ∑(TCS+TCC), ∑BPs, ∑BzPs, and ∑mPAEs were 3.36, 297, 3.87, 4.39, 0.257, and 4.56 ng/mL, respectively. The serum concentrations of ∑PBs, ∑MBs, ∑(TCS+TCC), and ∑mPAEs from infertile women (GM: 4.16, 397, 4.01, and 7.33, respectively) were higher than those from fertile women (2.45, 192, 3.65, and 2.27, respectively) (p < 0.05). The results of binary logistic regression and random forest suggest that mPAEs, such as mBP/miBP and mEHP, may contribute to infertility. This study provides insight into the relationship between the EDC exposure and reproductive outcomes.

Prenatal Exposure to Dibutyl Phthalate and Its Negative Health Effects on Offspring: In Vivo and Epidemiological Studies

Dibutyl phthalate (DBP) is a low-molecular-weight phthalate commonly found in personal care products, such as perfumes, aftershaves, and nail care items, as well as in children's toys, pharmaceuticals, and food products. It is used to improve flexibility, make polymer products soft and malleable, and as solvents and stabilizers in personal care products. Pregnancy represents a critical period during which both the mother and the developing embryo can be significantly impacted by exposure to endocrine disruptors. This article aims to elucidate the effects of prenatal exposure to DBP on the health and development of offspring, particularly on the reproductive, neurological, metabolic, renal, and digestive systems. Extensive research has examined the effects of DBP on the male reproductive system, where exposure is linked to decreased testosterone levels, reduced anogenital distance, and male infertility. In terms of the female reproductive system, DBP has been shown to elevate serum estradiol and progesterone levels, potentially compromising egg quality. Furthermore, exposure to this phthalate adversely affects neurodevelopment and is associated with obesity, metabolic disorders, and conditions such as hypospadias. These findings highlight how urgently stronger laws prohibiting the use of phthalates during pregnancy are needed to lower the risks to the fetus's health and the child's development.

Levels, distribution, and health risk assessment of phthalic acid esters in urban surface soils of Nagpur city, India

Surface soil samples from residential, commercial, and industrial areas of Nagpur city, India, were collected to study the levels, distribution, and impact of land use patterns on phthalic acid ester (PAEs) contamination. The Σ6PAEs concentrations in soils from residential, commercial, and industrial areas ranged between 6,493 to 13,195 µg/kg, 707 to 18,446 µg/kg, and 1,882 to 5,004 µg/kg with medians of 10,399, 6,199, and 3,401 µg/kg, respectively. Bis-2-ethylhexyl phthalate (DEHP) and dimethyl phthalate (DMP) were the dominant PAEs in the urban soils. The concentrations of DEHP and DMP were significantly greater than those in Ontario's soil quality guidelines. Among the PAEs, benzyl-butyl phthalate (BzBP) was found at relatively high concentrations (1,238 and 9,171 µg/kg) at two locations (i.e., S1 and S15). The chronic toxic risk (CTR) of PAEs was below the threshold, although the risk to children through ingestion and dermal exposure routes was greater than that to adults. The CR due to BzBP and DEHP were below the threshold level; however, the CR due to DMP was > 1 × 10-6 in residential areas. The cumulative CR of the six PAEs for adults (1.33-1.41 × 10-5) and children (8.08-8.89 × 10-6) surpassed the threshold level. This study revealed that PAEs in urban soils pose a risk to public health and require immediate risk reduction strategies.

Concentration levels of phthalate metabolites in wild boar hair samples

Phthalates used in the industry penetrate the environment and negatively affect humans and animals. Hair samples seem to be the best matrix for studies on long-term exposure to phthalates, but till now they were used only in investigations on humans. Moreover, the knowledge of the wild terrestrial animal exposure to phthalates is extremely limited. This study aimed to establish of concentration levels of selected phthalate metabolites (i.e. monomethyl phthalate-MMP, monoethyl phthalate-MEP, mono-isobutyl phthalate-MiBP, monobutyl phthalate-MBP, monobenzyl phthalate-MBzP, mono-cyclohexyl phthalate-MCHP, mono(2-ethylhexyl) phthalate-MEHP and mono-n-octyl phthalate-MOP) in wild boar hair samples using liquid chromatography with mass spectrometry (LC-MS) analysis. MEHP was noted in 90.7% of samples with mean 66.17 ± 58.69 pg/mg (median 49.35 pg/mg), MMP in 59.3% with mean 145.1 ± 310.6 pg/mg (median 64.45 pg/mg), MiBP in 37.0% with mean 56.96 ± 119.4 pg/mg (median < limit of detection-LOD), MBP in 35.2% with mean 19.97 ± 34.38 pg/mg (median < LOD) and MBzP in 1.9% with concentration below limit of quantification. MEP, MCHP, and MOP have not been found in wild boar hair samples during this study. The results have shown that wild boars are exposed to phthalates and hair samples may be used as a matrix during studies on levels of phthalate metabolites in wild animals.

Multi-target aptamer assay for endocrine-disrupting phthalic acid ester panel screening in plastic leachates

A multi-target aptamer assay was developed as a phthalic acid ester (PAE) panel to screen selected PAEs in plastic leachate samples. The panel comprises 13 PAEs (PAE-13), namely dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, di-n-hexyl phthalate, diisobutyl phthalate, diisononyl phthalate, diisodecyl phthalate, mono-2-ethylhexyl phthalate, di-2-ethylhexyl phthalate, diphenyl phthalate, butyl benzyl phthalate, dicyclohexyl phthalate, and phthalic acid. Herein, we proposed an aptamer assay using a newly truncated aptamer (20-mer) and the 7-aminoactinomycin D fluorophore, which selectively binds to guanine in single-stranded DNA, resulting in increased fluorescence intensity. The assay is highly selective for PAE-13 clusters. The selectivity of the assay was evaluated using 13 different PAEs and mixtures depending on the side chain structure. The quantitative detection of PAEs was demonstrated by adopting mixed PAE-13 simulants and achieved a limit of detection of ∼1.4 pg/mL. The repeatability and reproducibility of the assay were also evaluated by presenting acceptable coefficients of variation (%CV less than 10% and 15%, respectively). The performance of the assay was demonstrated by analyzing the plastic leachate samples, and the positive correlation (correlation coefficient, r = 0.985) was confirmed by comparing them with the total sum of individual PAE peak areas obtained by gas chromatography mass spectrometry analysis.

Oxidative damage to mitochondrial DNA in maternal zebrafish (Danio rerio) exposed to dibutyl phthalate at environmentally relevant level

Dibutyl phthalate (DBP) is a widely-used plasticizer that is dispersed in various environments, causing significant pollution and health risks. The toxic mechanism of DBP has been discussed in recent years, while the susceptibility of mitochondrial DNA (mtDNA) to DBP exposure and the resulting damage remain unclear. In this study, maternal zebrafish were exposed to environmentally relevant concentration of DBP for 0, 2, 4, and 6 weeks. Results showed that DBP exposure impaired health status, leading to the reduced body length and weight, condition factor, hepatosomatic index, and gonadosomatic index. Furthermore, DBP exposure induced oxidative stress and ATP deficiency in the gill and liver in a time-dependent manner. The oxidized mtDNA (ox-mtDNA) levels in the D-loop and ND1 regions were assessed in different tissues, showing distinct response patterns. The high energy-consuming tissues such as heart, brain, gill, and liver exhibited elevated susceptibility to mitochondrial damage, with a rapid increase in ox-mtDNA levels in the short term. Conversely, in muscle, ovary, eggs, and offspring, ox-mtDNA gradually accumulated over the exposure period. Notably, the ox-mtDNA levels in the D-loop region of blood showed a prompt response to DBP exposure, making it convenient for evaluation. Additionally, decreased hatching rates, increased mortality, lipoperoxidation, and depressed swimming performance were observed in offspring following maternal DBP exposure, suggesting the inherited impairments of maternal mtDNA. These findings highlight the potential for ox-mtDNA to serve as a convenient biomarker for environmental contamination, aiding in ecological risk assessment and forewarning systems in aquatic environment.

Regrettable Substitutes and the Brain: What Animal Models and Human Studies Tell Us about the Neurodevelopmental Effects of Bisphenol, Per- and Polyfluoroalkyl Substances, and Phthalate Replacements

In recent decades, emerging evidence has identified endocrine and neurologic health concerns related to exposure to endocrine-disrupting chemicals (EDCs), including bisphenol A (BPA), certain per- and polyfluoroalkyl compounds (PFASs), and phthalates. This has resulted in consumer pressure to remove these chemicals from the market, especially in food-contact materials and personal care products, driving their replacement with structurally or functionally similar substitutes. However, these "new-generation" chemicals may be just as or more harmful than their predecessors and some have not received adequate testing. This review discusses the research on early-life exposures to new-generation bisphenols, PFASs, and phthalates and their links to neurodevelopmental and behavioral alterations in zebrafish, rodents, and humans. As a whole, the evidence suggests that BPA alternatives, especially BPAF, and newer PFASs, such as GenX, can have significant effects on neurodevelopment. The need for further research, especially regarding phthalate replacements and bio-based alternatives, is briefly discussed.

Ameliorative effects of zinc and vitamin E against phthalates-induced reproductive toxicity in male rats

OBJECTIVE

Phthalates (PEs) could cause reproductive harm to males. A mixture of three widely used PEs (MPEs) was used to investigate the ameliorative effects of zinc (Zn) and vitamin E (VE) against male reproductive toxicity.

METHODS

Fifty male SD rats were randomly divided into five groups (n = 10). Rats in MPEs group were orally treated with 160 mg/kg/d MPEs, while rats in MPEs combined Zn and/or VE groups were treated with 160 mg/kg/d MPEs plus 25 mg/kg/d Zn and/or 25 mg/kg/d VE. After intervention for 70 days, it's was measured of male reproductive organs' weight, histopathological observation of sperms and testes, serum hormones, PIWI proteins and steroidogenic proteins.

RESULTS

Compared with control, anogenital distance, testes weight, epididymides weight, and sex hormones were significantly decreased, while the sperm malformation rate was markedly increased in MPEs group (p < .05); the testicular tissues were injured in MPEs group with disordered and decreased spermatids, and arrested spermatogenesis. PIWIL1, PIWIL2, StAR, CYP11A1 and CYP19A1 were down-regulated in MPEs group (p < .05). However, the alterations of these parameters were restored in MPEs combined Zn and/or VE groups (p < .05).

CONCLUSION

Zn and/or VE improved steroid hormone metabolism, and inhibited MPEs' male reproductive toxicity.

First Insight into Fetal Exposure to Legacy and Emerging Plasticizers Revealed by Infant Hair and Meconium: Occurrence, Biotransformation, and Accumulation

Epidemiological studies have demonstrated the embryonic and developmental toxicity of plasticizers. Thus, understanding the in utero biotransformation and accumulation of plasticizers is essential to assessing their fate and potential toxicity in early life. In the present study, 311 infant hair samples and 271 paired meconium samples were collected at birth in Guangzhou, China, to characterize fetal exposure to legacy and emerging plasticizers and their metabolites. Results showed that most of the target plasticizers were detected in infant hair, with medians of 9.30, 27.6, and 0.145 ng/g for phthalate esters (PAEs), organic phosphate ester (OPEs), and alternative plasticizers (APs), and 1.44, 0.313, and 0.066 ng/g for the metabolites of PAEs, OPEs, and APs, respectively. Positive correlations between plasticizers and their corresponding primary metabolites, as well as correlations among the oxidative metabolites of bis(2-ethylhexyl) phthalate (DEHP) and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), were observed, indicating that infant hair retained the major phase-I metabolism of the target plasticizers. While no positive correlations were found in parent compounds or their primary metabolites between paired infant hair and meconium, significant positive correlations were observed among secondary oxidative metabolites of DEHP and DINCH in hair and meconium, suggesting that the primary metabolites in meconium come from hydrolysis of plasticizers in the fetus but most of the oxidative metabolites come from maternal-fetal transmission. The parent compound/metabolite ratios in infant hair showed a decreasing trend across pregnancy, suggesting in utero accumulation and deposition of plasticizers. To the best of our knowledge, this study is the first to report in utero exposure to both parent compounds and metabolites of plasticizers by using paired infant hair and meconium as noninvasive biomonitoring matrices and provides novel insights into the fetal biotransformation and accumulation of plasticizers across pregnancy.

Association between phthalate metabolite mixture in neonatal cord serum and birth outcomes

Prenatal exposure to phthalates (PAEs) is ubiquitous among Chinese neonates. PAEs entering the body will be transformed to various hydrolyzed and oxidated PAE metabolites (mPAEs). PAEs and mPAEs exposure may lead to adverse birth outcomes through disruption of multiple hormone signaling pathways, induction of oxidative stress, and alterations in intracellular signaling processes. In this study, the concentrations of 11 mPAEs in 318 umbilical cord serum samples from neonates in Jinan were quantified with HPLC-ESI-MS. Multiple linear regression, Bayesian kernel machine regression, and quantile g-computation models were utilized to investigate the effects of both individual mPAE and mPAE mixture on birth outcomes. Stratified analysis was performed to explore whether these effects were gender-specific. mPAE mixture was negatively associated with birth length (BL) z-score, birth weight (BW) z-score, head circumference (HC) z-score, and ponderal index (PI). Mono(2-ethylhexyl) phthalate (MEHP) manifested negative associations with BL(z-score), BW(z-score), HC(z-score), and PI, whereas mono(2-carboxymethylhexyl) phthalate (MCMHP) was negatively associated with BW(z-score) and PI within the mPAE mixture. Stratified analysis revealed that the negative associations between mPAE mixture and four birth outcomes were attenuated in female infants, while the positive impact of mono(2-ethyl-5carboxypentyl) phthalate (MECPP) on BL(z-score) and BW(z-score) could be detected only in females. In summary, our findings suggest that prenatal exposure to phthalates may be associated with intrauterine growth restriction, and these effects vary according to the gender of the infant.

An exposome atlas of serum reveals the risk of chronic diseases in the Chinese population

Although adverse environmental exposures are considered a major cause of chronic diseases, current studies provide limited information on real-world chemical exposures and related risks. For this study, we collected serum samples from 5696 healthy people and patients, including those with 12 chronic diseases, in China and completed serum biomonitoring including 267 chemicals via gas and liquid chromatography-tandem mass spectrometry. Seventy-four highly frequently detected exposures were used for exposure characterization and risk analysis. The results show that region is the most critical factor influencing human exposure levels, followed by age. Organochlorine pesticides and perfluoroalkyl substances are associated with multiple chronic diseases, and some of them exceed safe ranges. Multi-exposure models reveal significant risk effects of exposure on hyperlipidemia, metabolic syndrome and hyperuricemia. Overall, this study provides a comprehensive human serum exposome atlas and disease risk information, which can guide subsequent in-depth cause-and-effect studies between environmental exposures and human health.

PPARβ/δ-ANGPTL4 axis mediates the promotion of mono-2-ethylhexyl phthalic acid on MYCN-amplified neuroblastoma development

Di-2-ethylhexyl phthalic acid (DEHP) is one of the most widely used plasticizers in the industry, which can improve the flexibility and durability of plastics. It is prone to migrate from various daily plastic products through wear and leaching into the surrounding environment and decompose into the more toxic metabolite mono-2-ethylhexyl phthalic acid (MEHP) after entering the human body. However, the impacts and mechanisms of MEHP on neuroblastoma are unclear. We exposed MYCN-amplified neuroblastoma SK-N-BE(2)C cells to an environmentally related concentration of MEHP and found that MEHP increased the proliferation and migration ability of tumor cells. The peroxisome proliferator-activated receptor (PPAR) β/δ pathway was identified as a pivotal signaling pathway in neuroblastoma, mediating the effects of MEHP through transcriptional sequencing analysis. Because MEHP can bind to the PPARβ/δ protein and initiate the expression of the downstream gene angiopoietin-like 4 (ANGPTL4), the PPARβ/δ-specific agonist GW501516 and antagonist GSK3787, the recombinant human ANGPTL4 protein, and the knockdown of gene expression confirmed the regulation of the PPARβ/δ-ANGPTL4 axis on the malignant phenotype of neuroblastoma. Based on the critical role of PPARβ/δ and ANGPTL4 in the metabolic process, a non-targeted metabolomics analysis revealed that MEHP altered multiple metabolic pathways, particularly lipid metabolites involving fatty acyls, glycerophospholipids, and sterol lipids, which may also be potential factors promoting tumor progression. We have demonstrated for the first time that MEHP can target binding to PPARβ/δ and affect the progression of neuroblastoma by activating the PPARβ/δ-ANGPTL4 axis. This mechanism confirms the health risks of plasticizers as tumor promoters and provides new data support for targeted prevention and treatment of neuroblastoma.

Phthalate metabolites in breast milk from mothers in Southern China: Occurrence, temporal trends, daily intake, and risk assessment

The extensive production and use of phthalates means that these compounds are now ubiquitous in the environment and various biota, which raises concerns about potential harmful health effects. In this study, phthalate metabolites (mPAEs) were measured in breast milk (n = 100) collected from mothers of southern China between 2014 - 2022. Of the nine target mPAEs, five were detected in all of the samples, including mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP), mono-isobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and mono-(2-ethylhexyl) phthalate (MEHP). The total levels of mPAEs in breast milk ranged from 4.76 to 51.6 ng/mL, with MiBP and MnBP being the predominant isomers (MiBP + MnBP > 48.3%). Increasing trends were observed in MMP (5.7%/year) and MEHP (7.1%/year) levels during the study period, while a decreasing trend were observed in MiBP (-6.6%/year); no clear temporal trends were found for the other metabolites and total mPAE levels. The results indicate that exposure to phthalates is still prevalent in southern China. Breastfeeding was found to contribute to estimated daily phthalate intakes of 0.383-6.95 μg/kg-bw/day, suggesting insignificant health risks to infants based on dietary exposure. However, the increasing exposure to MMP and MEHP calls for more research into the possible sources and potential risks.

Long-term exposure to the mixture of phthalates induced male reproductive toxicity in rats and the alleviative effects of quercetin

Phthalates (PEs), such as di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and butyl benzyl phthalate (BBP) could cause reproductive and developmental toxicities, while human beings are increasingly exposed to them at low-doses. Phytochemical quercetin (Que) is a flavonoid that has estrogenic effect, anti-inflammatory and anti-oxidant effects. This study was conducted to assess the alleviative effect of Que. on male reproductive toxicity induced by the mixture of three commonly used PEs (MPEs) at low-dose in rats, and explore the underlying mechanism. Male rats were treated with MPEs (16 mg/kg/day) and/or Que. (50 mg/kg/d) for 91 days. The results showed that MPEs exposure caused male reproductive injuries, such as decreased serum sex hormones levels, abnormal testicular pathological structure, increased abnormal sperm rate and changed expressions of PIWIL1 and PIWIL2. Furthermore, MPEs also changed the expression of steroidogenic proteins in steroid hormone metabolism, including StAR, CYP11A1, CYP17A1, 17β-HSD, CYP19A1. However, the alterations of these parameters were reversed by Que. MPEs caused male reproductive injuries in rats; Que. inhibited MPEs' male reproductive toxicity, which might relate to the improvement of testosterone biosynthesis.

Alleviative effect of quercetin against reproductive toxicity induced by chronic exposure to the mixture of phthalates in male rats

Phthalates (PEs) are widely used plasticizers in polymer products, and humans are increasingly exposed to them. This study was designed to investigate the alleviative effect of phytochemicals quercetin (Que) against male reproductive toxicity caused by the mixture of three commonly used PEs (MPEs), and further to explore the underlying mechanism. Forty-eight male SD rats were randomly and evenly divided into control group, Que group, MPEs group and MPEs+Que group (n = 12); The oral exposure doses of MPEs and Que were 450 mg/kg/d and 50 mg/kg/d, respectively. After 91 days of continuous intervention, compared with control group, the testes weight, epididymis weight, serum sex hormones, and anogenital distance were significantly decreased in MPEs group (P < 0.05); Testicular histopathological observation showed that all seminiferous tubules were atrophy, leydig cells were hyperplasia, spermatogenic cells growth were arrested in MPEs group. Ultrastructural observation of testicular germ cells showed that the edges of the nuclear membranes were indistinct, and the mitochondria were severely damaged with the cristae disrupted, decreased or even disappeared in MPEs group. Immunohistochemistry and Western blot analysis showed that testicular CYP11A1, CYP17A1 and 17β-HSD were up-regulated, while StAR, PIWIL1 and PIWIL2 were down-regulated in MPEs group (P < 0.05); However, the alterations of these parameters were restored in MPEs+Que group. The results indicated MPEs disturbed steroid hormone metabolism, and caused male reproductive injuries; whereas, Que could inhibit MPEs' male reproductive toxicity, which might relate to the restored regulation of steroid hormone metabolism.

Endoplasmic reticulum stress and pro-inflammatory responses induced by phthalate metabolites monoethylhexyl phthalate and monobutyl phthalate in 1.1B4 pancreatic beta cells

In recent years, phthalates and their metabolites have been associated with metabolic diseases such as diabetes mellitus. To investigate the effects of phthalate metabolites exposure on insulin production and release, 1.1B4 pancreatic beta cells were treated with different concentrations (0.001-1000 µM) of monoethylhexyl phthalate (MEHP) and monobutyl phthalate (MBP). For such purpose, the 1.1B4 cells were evaluated for their viability, apoptosis rate, lysosomal membrane permeabilization (LMP), mitochondrial membrane potential (ΔΨm), oxidative stress, ER stress status, in addition to their secretory functions. MEHP, not MBP, exhibited a notable reduction in metabolic viability, particularly at higher concentrations (500 and 1000 µM) following 24-hour exposure. Similarly, both MEHP and MBP induced decreased metabolic viability at high concentrations after 48- and 72-hour exposure. Notably, neither MEHP nor MBP demonstrated a significant impact on apoptosis rates after 24-hour exposure, and MBP induced mild necrosis at 1000 µM concentration. Cell proliferation rates, indicated by PCNA expression, decreased with 10 and 1000 µM MEHP and 0.1 and 10 µM MBP exposures. LMP analysis revealed an increase in 1000 µM MBP group. Exposure to 0.001 µM of both MEHP and MBP significantly reduced cellular glutathione (GSH) levels. No significant change in intracellular reactive oxygen species (ROS) levels and ΔΨm was observed, but MBP-exposed cells exhibited elevated levels of lipid peroxidation. Functional assessments of pancreatic beta cells unveiled reduced insulin secretion at low glucose concentrations following exposure to both MEHP and MBP, with concurrent alterations in the expression levels of key proteins associated with beta cell function, including GLUT1, GCK, PDX1, and MafA. Moreover, MEHP and MBP exposures were associated with alterations in ER stress-related pathways, including JNK, GADD153, and NF-κB expression, as well as PPARα and PPARγ levels. In conclusion, this study provides comprehensive insights into the diverse impacts of MEHP and MBP on 1.1B4 pancreatic beta cells, emphasizing their potential role in modulating cell survival, metabolic function, and stress response pathways.

Adverse cardiovascular effects of long-term exposure to diethyl phthalate in the rat aorta

Phthalates are classified as priority environmental pollutants, since they are ubiquitous in the environment, have endocrine disrupting properties and can contribute to impaired health. Used primarily in personal care products and excipients for pharmaceuticals, diethyl phthalate (DEP) is a short-chain alkyl phthalate that has been linked to decreased blood pressure, glucose tolerance, and increased gestational weight gain in humans, while in animals it has been associated with atherosclerosis and metabolic syndrome. Although all these findings are related to risk factors or cardiovascular diseases, DEP's vascular impacts still need to be clarified. Thus, performing ex vivo and in vitro experiments, we aimed to understand the vascular DEP effects in rat. To evaluate the vascular contractility of rat aorta exposed to different doses of DEP (0.001-1000 μM), an organs bath was used; and resorting to a cell line of the rat aorta vascular smooth muscle, electrophysiology experiments were performed to analyse the effects of a rapid (within minutes with no genomic effects) and a long-term (24 h with genomic effects) exposure of DEP on the L-type Ca2+ current (ICa,L), and the expression of several genes related with the vascular function. For the first time, vascular electrophysiological properties of an EDC were analysed after a long-term genomic exposure. The results show a hormetic response of DEP, inducing a Ca2+ current inhibition of the rat aorta, which may be responsible for impaired cardiovascular electrical health. Thus, these findings contribute to a greater scientific knowledge about DEP's effects in the cardiovascular system, specifically its implications in the development of electrical disturbances like arrhythmias and its possible mechanisms.

Mono-(2-ethylhexyl)-phthalate potentiates methylglyoxal-induced blood-brain barrier damage via mitochondria-derived oxidative stress and bioenergetic perturbation

Phthalates in contaminated foods and personal care products are one of the most frequently exposed chemicals with a public health concern. Phthalate exposure is related to cardiovascular diseases, including diabetic vascular complications and cerebrovascular diseases, yet the mechanism is still unclear. The blood-brain barrier (BBB) integrity disruption is strongly associated with cardiovascular and neurological disease exacerbation. We investigated BBB damage by di-(2-ethylhexyl) phthalate (DEHP) or its metabolite mono-(2-ethylhexyl) phthalate (MEHP) using brain endothelial cells and rat models. BBB damage by the subthreshold level of MEHP, but not a DEHP, significantly increased by the presence of methylglyoxal (MG), a reactive dicarbonyl compound whose levels increase in the blood in hyperglycemic conditions in diabetic patients. Significant potentiation in apoptosis and autophagy activation, mitochondria-derived reactive oxygen species (ROS) production, and mitochondrial metabolic disturbance were observed in brain ECs by co-exposure to MG and MEHP. N-acetyl cysteine (NAC) restored autophagy activation as well as tight junction protein impairment induced by co-exposure to MG and MEHP. Intraperitoneal administration of MG and MEHP significantly altered mitochondrial membrane potential and tight junction integrity in rat brain endothelium. This study may provide novel insights into enhancing phthalate toxicity in susceptible populations, such as diabetic patients.

Cumulative Exposure to Phthalates and Their Alternatives and Associated Female Reproductive Health: Body Burdens, Adverse Outcomes, and Underlying Mechanisms

The global birth rate has recently shown a decreasing trend, and exposure to environmental pollutants has been identified as a potential factor affecting female reproductive health. Phthalates have been widely used as plasticizers in plastic containers, children's toys, and medical devices, and their ubiquitous presence and endocrine-disrupting potential have already raised particular concerns. Phthalate exposure has been linked to various adverse health outcomes, including reproductive diseases. Given that many phthalates are gradually being banned, a growing number of phthalate alternatives are becoming popular, such as di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH), di(2-ethylhexyl) adipate (DEHA), and di(2-ethylhexyl) terephthalate (DEHTP), and they are beginning to have a wide range of environmental effects. Studies have shown that many phthalate alternatives may disrupt female reproductive function by altering the estrous cycle, causing ovarian follicular atresia, and prolonging the gestational cycle, which raises growing concerns about their potential health risks. Herein, we summarize the effects of phthalates and their common alternatives in different female models, the exposure levels that influence the reproductive system, and the effects on female reproductive impairment, adverse pregnancy outcomes, and offspring development. Additionally, we scrutinize the effects of phthalates and their alternatives on hormone signaling, oxidative stress, and intracellular signaling to explore the underlying mechanisms of action on female reproductive health, because these chemicals may affect reproductive tissues directly or indirectly through endocrine disruption. Given the declining global trends of female reproductive capacity and the potential ability of phthalates and their alternatives to negatively impact female reproductive health, a more comprehensive study is needed to understand their effects on the human body and their underlying mechanisms. These findings may have an important role in improving female reproductive health and in turn decreasing the number of complications during pregnancy.

Environmentally relevant concentrations of butyl benzyl phthalate triggered oxidative stress and apoptosis in adult zebrafish (Danio rerio) liver: Combined analysis at physiological and molecular levels

Butyl benzyl phthalate (BBP), a typical phthalate plasticizer, is frequently detected in aquatic environments, but its possible effects on fish liver are unknown. In this study, adult zebrafish were exposed to 5-500 μg/L BBP and cultured for 28 days. The toxicity mechanism of environmentally relevant concentrations of BBP in the liver was explored using integrated biomarker response (IBR), molecular docking, and histopathological analysis, based on the tests of oxidative stress, apoptosis, and tissue damage, respectively. The results revealed that exposure to 500 μg/L BBP caused lipid peroxidation and DNA damage and induced inflammatory responses in the liver and intestinal tissues. The accumulation of reactive oxygen species (ROS) is the primary manifestation of BBP toxicity and is accompanied by changes in the activities of antioxidant and detoxification enzymes. Notably, the pro-apoptotic genes (p53 and caspase-3) were still significantly upregulated in the 50 μg/L and 500 μg/L treatment groups on day 28. Moreover, BBP interfered with apoptosis by forming a stable complex with apoptosis proteins (P53 and Caspase-3). Our findings are helpful for understanding the toxicity mechanisms of BBP, which could further promote the assessment of the potential environmental risks of BBP.

Risk Assessment of Phthalates and Their Metabolites in Hospitalized Patients: A Focus on Di- and Mono-(2-ethylhexyl) Phthalates Exposure from Intravenous Plastic Bags

Phthalate esters (PAEs) are plasticizers associated with multiple toxicities; however, no strict regulations have been implemented to restrict their use in medical applications in Lebanon. Our study aimed at assessing the potential risks correlated with phthalate exposure from IV bags manufactured in Lebanon. GC–MS analysis showed that di-(2-ethylhexyl) phthalate (DEHP) is the predominant phthalate found in almost all samples tested with values ranging from 32.8 to 39.7% w/w of plastic. DEHP concentrations in the IV solutions reached up to 148 µg/L, as measured by SPME-GC–MS/MS, thus resulting in hazard quotients greater than 1, specifically in neonates. The toxicity of DEHP is mainly attributed to its metabolites, most importantly mono-(2-ethylhexyl) phthalate (MEHP). The IV bag solution with the highest content in DEHP was therefore used to extrapolate the amounts of urinary MEHP. The highest concentrations were found in neonates having the lowest body weight, which is concerning, knowing the adverse effects of MEHP in infants. Our study suggests that the use of IV bags manufactured in Lebanon could pose a significant risk in hospitalized patients, especially infants in neonatal care. Therefore, Lebanon, as well as other countries, should start imposing laws that restrict the use of phthalates in medical IV bags and substitute them with less toxic plasticizers.

Modeling di (2-ethylhexyl) Phthalate (DEHP) and Its Metabolism in a Body's Organs and Tissues through Different Intake Pathways into Human Body

Phthalate esters (PAEs) are ubiquitous in indoor environments as plasticizers in indoor products. Residences are often exposed to indoor PAEs in the form of gas, particles, settled dust, and surface phases. To reveal the mechanism behind the accumulation of PAEs in different tissues or organs such as the liver and the lungs when a person exposed to indoor PAEs with different phases, a whole-body physiologically based pharmacokinetic model for PAEs is employed to characterize the dynamic process of phthalates by different intake pathways, including oral digestion, dermal adsorption, and inhalation. Among three different intake pathways, dermal penetration distributed the greatest accumulation of DEHP in most of the organs, while the accumulative concentration through oral ingestion was an order of magnitude lower than the other two doses. Based on the estimated parameters, the variation of di-ethylhexyl phthalate (DEHP) and mono (2-ethylhexyl) phthalate (MEHP) concentration in the venous blood, urine, the liver, the thymus, the pancreas, the spleen, the lungs, the brain, the heart, and the kidney for different intake scenarios was simulated. The simulated results showed a different accumulation profile of DEHP and MEHP in different organs and tissues and demonstrated that the different intake pathways will result in different accumulation distributions of DEHP and MEHP in organs and tissues and may lead to different detrimental health outcomes.