Phthalate metabolites: Characterization, toxicities, global distribution, and exposure assessment

Associations between phthalate metabolites and two novel systemic inflammatory indexes: a cross-sectional analysis of NHANES data

BACKGROUND

The potentially risky effects of metabolites of phthalates (mPAEs) on inflammation and immune function have attracted much attention in recent years. However, direct studies on the relationship between these metabolites and the systemic immune inflammatory index (SII) and systemic inflammatory response index (SIRI) are limited.

METHODS

This cross-sectional study used generalized linear regression models (GLM), restricted cubic splines (RCS), weighted quantile sum (WQS), and Bayesian kernel-machine regression (BKMR) to analyze data from 2,763 U.S. adults aged between 20 and 80 years, obtained from the U.S. National Health and Nutrition Examination Survey (NHANES) conducted between 2013 and 2018. The study aimed to investigate the relationship between urine samples of nine mPAEs and levels of SII/SIRI in a single, nonlinear, and mixed relationship and explored the robustness of the findings under single and mixed effects using two sensitivity analyses for completeness. In addition, the effects of six variables (age, sex, BMI, the percentage of total daily energy intake from ultra-processed foods (UPFs), total vegetable intake, and dietary supplements) on the association results were explored through subgroup analyses to identify potentially important confounders.

RESULTS

In single exposure analyses, mono-n-butyl phthalate (MnBP), mono-ethyl phthalate (MEP), and monobenzyl phthalate (MBzP) were positively associated with SII/SIRI. The findings from the two mixed exposure models demonstrated a positive association between the collective concentrations of mPAEs and levels of SII/SIRI, with MBzP being identified as a significant contributor to the urinary levels of mPAEs. The subgroup analysis results of the effects of single and mixed exposures show that the association between mPAEs and SII/SIRI is more significant in females, overweight/obese populations, young/middle-aged populations, and populations with high levels of intake of UPFs.

CONCLUSION

Positive associations were identified between mPAEs and SII/SIRI. MBzP was determined to have the most significant impact. The association between mPAEs and SII/SIRI is significantly influenced by female groups, young and middle-aged populations, overweight and obese individuals, as well as those with a higher intake of UPFs.

Uptake, translocation, and biotransformation of phthalate acid esters in crop plants: A comprehensive review

Phthalate acid esters (PAEs) are prevalent emerging contaminants in agricultural environments. The uptake of PAEs by crop plants has attracted extensive attention due to the risks posed to human health through transfer in food chains. Despite its importance, the interaction between PAEs and crop plants remains poorly understood. In this critical review, the occurrence of six priority control PAEs in various food crops grown in greenhouses and conventional farms is investigated, with detected concentrations reaching up to mg/kg (dry weight) levels. PAEs enter plants through roots, foliar gas, or foliar particle uptake. After entry, PAEs exhibit acropetal translocation from the root and basipetal translocation from the leaf. PAEs are transformed into various metabolites through hydroxylation, hydrolysis, and oxidation in phase I metabolism and further conjugated with biomolecules such as amino acids or sugars in phase II metabolism. Exposure to PAEs disrupts plant homeostasis and activated antioxidant enzymes to alleviate phytotoxicity. Dietary intake of PAEs-contaminated food crops presents potential risks to human health, particularly from fruit and root vegetables consumed by children, warranting specific attention. Furthermore, current knowledge gaps and future perspectives are proposed. This review provides a comprehensive assessment of the knowledge on the uptake, translocation, and transformation of PAEs in crop plants, emphasizing the need for an integrated investigation into the full life cycle of PAEs in plants to ensure food safety.

An automated liquid-liquid extraction platform for high-throughput sample preparation of urinary phthalate metabolites in human biomonitoring

Automated sample preparation reduces variation caused by human factors and improves efficiency, throughput, and reliability, making it especially important in large-scale epidemiological biomonitoring applications. In this study, we demonstrated an automated liquid-liquid extraction platform that streamlines sample preparation for human biomonitoring of urinary phthalate metabolites. This platform integrates temperature-controlled enzymatic hydrolysis, adds extraction solvents, conducts shaking extraction, performs centrifugal separation, and transfers liquids. We optimized extraction solvents for liquid-liquid extraction of urinary phthalate metabolites and compared the extraction efficiency between manual and automated methods. The analytical performance of the platform was validated and compared with those obtained by manual liquid-liquid extraction and solid-phase extraction methods. We applied the automated liquid-liquid platform for determining urinary phthalate metabolites in the human biomonitoring of 232 health participants and evaluated their association with oxidative stress levels. Urinary phthalate metabolite concentrations showed a clear declining trend with increasing age. Males had significantly higher total urinary concentrations of phthalate metabolites than females. Monobutyl phthalate was the dominant metabolite in urine samples, followed by mono-isobutyl phthalate and monoethyl phthalate, with minor gender differences observed among individual metabolites. Trend tests and Bayesian Kernel Machine Regression analysis showed a significant positive association between urinary phthalate metabolites and the oxidative stress markers 8-hydroxyguanosine and 8-hydroxy-2'-deoxyguanosine, and monobutyl phthalate was identified as the most significant metabolite for the elevated 8-hydroxy-2'-deoxyguanosine levels. The automated liquid-liquid extraction platform exhibited high efficiency and reliability in preparing urinary samples for phthalate metabolite analysis, showing great promise in large-scale sample preparation of human biomonitoring applications.

Association between phthalate exposure and metabolic dysfunction-associated steatotic liver disease (MASLD) - Systematic literature review

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is rising globally. Recent studies have suggested connections between exposure to endocrine disrupting chemicals (EDCs) and the development of MASLD. Phthalates, which are commonly utilized as plasticizers, in building materials and consumer items, exhibit endocrine disrupting effects and have been shown to interfere with lipid metabolism in mechanistic studies. The objective of this systematic review was to examine the association between MASLD and exposure to phthalates in the adult human populations. We searched PubMed, Scopus and Web of Science for studies published from the inception of each database until December 12, 2024. The literature search yielded 10 cross-sectional studies, which were analyzed in detail. The key findings of this study indicate a potential correlation between the prevalence of MASLD and exposure to certain phthalates. Among the phthalates examined, the metabolites of bis(2-ethylhexyl) phthalate (DEHP) - namely MECPP, MEHHP, and MEOHP, demonstrated the strongest and most frequent associations with MASLD. All the current studies followed cross-sectional study designs, which limits the possibility to establish a causal relationship between MASLD and phthalate exposure. Therefore, longitudinal studies are needed to corroborate these findings and shed light on the involvement of phthalate exposure in MASLD.

Unraveling the connection between endocrine-disrupting chemicals and anxiety: An integrative epidemiological and bioinformatic perspective

BACKGROUND

The evidence linking endocrine-disrupting chemicals (EDCs) to anxiety in adults is currently sparse, while the effects of various categories of EDCs on the risk of anxiety, along with the underlying mechanisms, remain poorly understood.

METHODS

Four EDCs-polycyclic aromatic hydrocarbons (PAHs), phenols, pesticides, and phthalates-were quantified in 3927 adults from the National Health and Nutrition Examination Survey (NHANES) (2007-2012). We employed five statistical models to assess the individual and joint impacts of EDCs on anxiety risk. Causal mediation analysis frameworks were constructed to explore the mediating role of oxidative stress (OS). We identified potential biological mechanisms linking analytes to outcomes using the Comparative Toxicogenomics Database (CTD), MalaCards, and Open Targets, followed by enrichment analyses with Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG).

RESULTS

In individual chemical analyses, nine PAHs were significantly associated with increased anxiety risk (P < 0.05). Mixed-effects analyses showed that co-exposure to EDCs positively correlated with anxiety, primarily due to 2-hydroxyfluorene (2-FLU) and 3-hydroxyfluorene (3-FLU). Bilirubin mediated 5.42 % of the anxiety linked to the PAH mixture. The inflammatory genes TNF and IL-6 were identified as key biological stressors, with enrichment analysis indicating significant involvement in reactive oxygen species metabolic processes and the AGE-RAGE signaling pathway.

CONCLUSION

This study highlights the association between EDCs and anxiety in a representative U.S. population, indicating that exposure to PAHs may elevate anxiety risk through OS, inflammation, and the AGE-RAGE signaling pathway. Further longitudinal study were merited to support our results.

Unveiling Human Exposure to Plasticizers through Drinking Tea: A Nationwide Study

Dietary intake represents a significant exposure pathway for phthalates (PAEs) and nonphthalate plasticizers (NPPs). However, the associated exposure risk linked to tea consumption remains unclear. This study analyzed 10 PAEs and 10 NPPs in six types of tea collected from 18 provinces in China. Both PAEs and NPPs were detected in all samples, with concentrations ranging from 309 to 8150 ng/g for PAEs and 42.2 to 899 ng/g for NPPs, respectively. Source apportionment analysis indicates that packaging materials are important sources of plasticizer contamination in tea. The concentrations of di-isobutyl phthalate (DiBP), benzyl-butyl phthalate (BzBP), and trioctyl trimellitate (TOTM) in tea exhibited a significant correlation with those found in packaging materials (r: 0.414-0.465, p < 0.01). Five transformation products (TPs) of plasticizers were identified in brewed tea samples through suspect screening analysis, raising concerns about their potential health effects. Comparisons suggest that cold brewing may result in higher plasticizer exposure than hot brewing after a single brew. However, as the brewing times for hot brewed tea increased, the risk of human exposure rose, ultimately exceeded that of cold brewed tea. This study provides national-scale data on plasticizer contamination in Chinese tea and valuable insights into tea consumption practices.

Associations between urinary phthalate metabolites and reproductive, adrenal, and gonadotropic hormones in peripubertal children: the Hokkaido study

Phthalates have raised concerns regarding the disruption of hormone synthesis and signaling. The purpose of this study was to investigate the associations between urinary phthalate metabolites and 18 hormones, including reproductive, adrenal, and gonadotropic hormones, in peripubertal children. The study comprised a cross-sectional analysis of participants in the Hokkaido Birth Cohort Study. We collected data from 429 school children aged 9-12 living in Sapporo, Japan. Ten phthalate metabolites and 14 steroid hormones were analyzed using LC-MS/MS, whereas four peptide hormones were detected using immunoassays. Multivariable linear regression, quantile-based g-computation (qg-computation), and Bayesian kernel machine regression (BKMR) were used to investigate the associations between the individual phthalate metabolites and the phthalate mixtures with hormone levels, as well as with puberty based on hormone levels. In girls, we found that higher phthalate metabolite levels, as well as phthalate mixtures, were significantly associated with lower dehydroepiandrostenedione-sulfate (DHEA-S) and higher (androstenedione + testosterone)/DHEA-S. The higher phthalate mixture showed lower levels of LH, FSH, and cortisol levels among girls, whereas higher 11-deoxycortisol levels. In boys, a higher phthalates mixture was significantly associated with a higher estradiol/testosterone ratio, whereas lower levels of insulin-like factor-3 (INSL3), testosterone, (androstenedione + testosterone)/DHEA-S, testosterone/androstenedione, and cortisol/cortisone. Higher phthalate mixtures were associated with lower prevalence of puberty in girls. These findings indicate that phthalate exposure may disrupt the hormones in children during puberty.

Periods of susceptibility for associations between phthalate exposure and preterm birth: Results from a pooled analysis of 16 US cohorts

BACKGROUND

Phthalate exposure during pregnancy has been associated with preterm birth, but mechanisms of action may depend on the timing of exposure.

OBJECTIVE

Investigate critical periods of susceptibility during pregnancy for associations between urinary phthalate metabolite concentrations and preterm birth.

METHODS

Individual-level data were pooled from 16 US cohorts (N = 6045, n = 539 preterm births). We examined trimester-averaged urinary phthalate metabolite concentrations. Most phthalate metabolites had 2248, 3703, and 3172 observations in the first, second, and third trimesters, respectively. Our primary analysis used logistic regression models with generalized estimating equations (GEE) under a multiple informant approach to estimate trimester-specific odds ratios (ORs) of preterm birth and significant (p < 0.20) heterogeneity in effect estimates by trimester. Adjusted models included interactions between each covariate and trimester.

RESULTS

Differences in trimester-specific associations between phthalate metabolites and preterm birth were most evident for di-2-ethylhexyl phthalate (DEHP) metabolites. For example, an interquartile range increase in mono (2-ethylhexyl) phthalate (MEHP) during the first and second trimesters was associated with ORs of 1.15 (95 % confidence interval [CI]: 0.99, 1.33) and 1.11 (95 % CI: 0.97, 1.28) for preterm birth, respectively, but this association was null in the third trimester (OR = 0.91 [95 % CI: 0.76, 1.09]) (p-heterogeneity = 0.03).

CONCLUSION

The association of preterm birth with gestational biomarkers of DEHP exposure, but not other phthalate metabolites, differed by the timing of exposure. First and second trimester exposures demonstrated the greatest associations. Our study also highlights methodological considerations for critical periods of susceptibility analyses in pooled studies.

Emerging Contaminants: An Important But Ignored Risk Factor for Psoriasis

Industrialization and modernization have changed the environment. A group of emerging contaminants (ECs) has been defined recently. Psoriasis, whose incidence has increased in recent years, is a relapsing immune-mediated disease carrying a heavy disease burden. The erythematous scaly plaque is a typical symptom and occurs on several parts of the body. In addition, psoriasis has many comorbidities, such as psoriatic arthritis, diabetes, and depression, damaging the quality of life of patients. IL-17, IL-12, IL-23, and TNF-alpha are important related cytokines. ECs can influence psoriasis through the immune system and inflammatory responses. Specific mechanisms include increasing pro-inflammatory cytokines such as TNF-α and IL-17, and activating immune cells such as macrophages. And for psoriasis patients, it is suggested to reduce the exposure of most ECs. However, the complex mechanisms involved have not been discussed together and concluded. In this review, we summarize the relationship between ECs and psoriasis, focusing on the immune system, especially the immune cells and cytokines. These results can help guide clinical treatment and long-term management of psoriasis.

Does healthy lifestyle attenuate the associations of phthalates with depression? A cross-sectional study

Phthalates have raised concerns on health outcomes including depression, due to its ubiquity. Knowledge is lacking on the role of modifiable lifestyle in attenuating phthalates' adverse effects. We aimed to evaluate the interaction effects of lifestyle with urinary phthalate metabolites (UPMs) on depression. A total of 3588 participants aged ≥ 20 from the National Health and Nutrition Examination Survey 2011-2018 were involved. We used multivariate logistic regression models and Bayesian Kernel Machine Regression models to evaluate the associations of UPMs (individual or mixture) and lifestyle with depression. Positive associations of individual UPMs and its mixture with depression were observed in total population and participants maintaining an unfavorable lifestyle. No such association was found in participants with a healthy lifestyle. Interactions between lifestyle category with MECPP (P for interaction = 0.028), and ΣDEHP (P for interaction = 0.087) on depression were observed. Additionally, smoking, alcohol consumption and physical activity in healthy levels showed the greatest effect against depression among the common lifestyle combinations. In conclusion, positive associations of UPMs with depression risk, and interaction effects of lifestyle and UPMs on depression were observed. Our findings indicate that healthy lifestyle might weaken the adverse effects of phthalate exposure on depression risk.

The role of lifestyle in the impact of constant phthalate exposure on overweight and obesity: A longitudinal cohort study in China

BACKGROUND AND OBJECTIVES

To explore the relationship between constant exposure to phthalates (PAEs) and overweight/obesity and the role of lifestyle in children.

METHODS

This study conducted five repeated follow-up visits with 829 children and analysed data from 740 children. Logistic regression models were used to evaluate the association between constant PAE exposure, lifestyle and overweight/obesity.

RESULTS

The study found that constant high levels of PAEs exposure may increase the risk of obesity in girls, and the risk is higher in girls with an unhealthy lifestyle. In the unhealthy lifestyle group of girls, compared with the constant low (CL) exposure group of PAEs, the odds ratios (ORs) for overweight/obesity and obesity in the constant high (CH) exposure group were 2.99 (1.11, 8.05) and 11.58 (1.38, 96.87), respectively. In addition, an interaction effect between constant exposure to PAEs and lifestyle was observed on obesity in girls.

CONCLUSION

These results suggest the importance of reducing constant exposure to high levels of PAEs to reduce the risk of obesity, especially in individuals with unhealthy lifestyles. The government should strengthen the formulation of regulations and standards for PAEs while guiding parents to use fewer plastic products.

Investigation of common and unreported parabens alongside other plastic-related contaminants in human milk using non-targeted strategies

Human milk studies analyzing widely used contaminants mainly utilize a targeted approach to screen and quantify a limited number of compounds. While targeted analysis allows health officials to quantify the levels of these chemicals in human milk, it fails to detect the presence of other unknowns that may be of equal importance. Hence, the objective of this study was to apply non-targeted analysis to detect and identify different prevalent contaminants, specifically common or unreported parabens as well as other plastic-related contaminants (PRCs) in human milk. Extracts of 594 human milk samples collected in Canada (Montreal) and South Africa (Vhembe and Pretoria) in 2018-2019 were analyzed using liquid chromatography-mass spectrometry to confirm the presence of methyl, ethyl and propyl parabens. Additional investigations revealed the presence of sulfated species of these parabens, suggesting their conjugation potential in human milk. Further analysis using in-source fragmentation, identified the presence of four other parabens in human milk, including phenyl paraben as well as 2-ethylhexyl 4-hydroxybenzoate, an unusual paraben exclusive to South African samples. Other PRCs that were detected included several phthalate metabolites, per- and poly-fluoroalkyl substances (PFAS) and 1,3 diphenyl guanidine, a tire-related chemical. This is the first study to have used different non-targeted analyses for the detection and confirmation of several common and unusual parabens alongside different PRCs in human milk.

Moderating effects of insomnia on the association between urinary phthalate metabolites and depressive symptoms in Chinese college students: focus on gender differences

OBJECTIVES

To investigate the rates of depressive symptoms in college students, explore the relationship between urinary phthalate metabolites and depressive symptoms and their gender differences, and further explore the moderating role of insomnia in this association.

METHODS

A total of 1 179 college students were recruited from 2 universities in Hefei and Shangrao cities from April to May 2019. The depressive symptoms and insomnia of college students were investigated by the Patient Health Questionnaire 9 and Insomnia Severity Index. The high-performance liquid chromatography-tandem mass spectrometry was adapted to determine the concentration of urinary phthalate metabolites. The generalized linear model was used to analyze the relationship of phthalate metabolites with depressive symptoms. Moderating analysis was used to examine whether insomnia moderated the relationship of phthalate metabolites with depressive symptoms.

RESULTS

The rates of mild depression, and moderate depression and above in college students were 31.9% and 9.2%, respectively. The phthalate metabolites exhibited a median and mean concentration spanning from 2.98 ∼ 156.55 ng/mL and 6.12 ∼ 205.53 ng/mL. The generalized linear model results showed that monobutyl phthalate (MBP) (β = 1.160, 95%CI: 0.423 ∼ 1.896) and low molecular weight phthalate (LMWP) (β = 1.230, 95%CI: 0.348 ∼ 2.113) were positively correlated with depressive symptoms, and MBP (β = 1.320, 95%CI: 0.453 ∼ 2.187) and LMWP (β = 1.396, 95%CI: 0.351 ∼ 2.440) were positively correlated with depressive symptoms only in female college students after stratified by gender. Furthermore, insomnia has a positive moderating role between MBP, LMWP, and depressive symptoms and has a sex-based difference.

CONCLUSIONS

This study suggests that there is a positive association of phthalate metabolites with depressive symptoms among Chinese college students, as well as insomnia plays a positive moderating role in this association.

Association between prenatal exposure to phthalate esters and blood pressure in children aged 3-7 years: A prospective cohort study

BACKGROUND

An increasing number of animal studies have indicated that exposure to phthalate esters (PAEs) may cause high blood pressure. However, population-based evidence is limited, particularly for pregnant women and young children.

OBJECTIVE

To examine the correlation between prenatal exposure to phthalate ester metabolites (mPAEs) and blood pressure in preschool children.

METHODS

In our cohort study, 497 pairs of mothers and children (aged 3-7 years) were enrolled at the Wuhan Maternal and Child Healthcare Hospital, Wuhan, China, between 2016 and 2017. Eight mPAEs were detected in the urine samples of pregnant women during the third trimester. Systolic (SBP) and diastolic blood pressure (DBP) were measured by physicians using an automated oscillometric sphygmomanometer and childhood hypertension was defined according to the American Academy of Pediatrics 2017 guidelines. Mixed-effects linear regression models were used to estimate the correlations between individual mPAEs and the SBP and DBP z-scores of preschoolers. Binary logistic regression models were used to examine the correlation between individual mPAEs and hypertension risk. A weighted quantile sum (WQS) regression was implemented to explore the correlation between mixed mPAEs and the SBP/DBP z-scores in children.

RESULT

Monomethyl phthalate, monobutyl phthalate (MBP), monoethyl phthalate, mono(2-ethylhexyl) phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate and mono(2-ethyl-5-oxohexyl) phthalate were significantly positively correlated with increases in the SBP and DBP z-scores, whereas MBP was significantly correlated with hypertension risk, with an odds ratio of 1.695 (95 % confidence interval: 1.322, 2.173). Moreover, the WQS regression analyses revealed that MBP increased SBP (67.7 %) and DBP (80.8 %).

CONCLUSIONS

The present study suggests that prenatal exposure to PAEs was positively correlated with increased blood pressure in pre-school children, and MBP is of particular concern because it contributed the most to the combined effect of PAE mixture on the risk of childhood hypertension.

The role of di-(2-ethylhexyl) phthalate in cancer initiation and progression: Mechanisms and health implications

The increasing prevalence of cancer has been linked to various environmental factors associated with modern industrial and societal advancements. Di-(2-ethylhexyl) phthalate (DEHP), a commonly used plasticizer, is one such environmental contaminant with potential carcinogenic effects. While epidemiological studies have suggested a positive association between DEHP exposure and cancer risk, the specific role of DEHP in cancer initiation and progression requires further clarification. This review systematically examines the relationship between DEHP exposure and cancer, highlighting key mechanisms involved in tumorigenesis. DEHP has been found to influence several critical aspects of cancer biology, including cell proliferation, apoptosis, metastasis, invasion, epithelial-mesenchymal transition, angiogenesis, drug resistance, immune regulation, and cancer stem cell maintenance. These carcinogenic effects are mediated through multiple pathways, such as the PI3K/AKT signaling pathway, estrogen receptor activation, epigenetic modifications, oxidative stress, and inflammation. By elucidating the molecular mechanisms underlying DEHP's role in cancer, this review aims to contribute to the development of targeted prevention and intervention strategies to mitigate the cancer risks associated with DEHP exposure.

Plastic harmful ingredients reduce the level of neurofilament light chain protein

Population exposure to plastics is increasing, and plasticizers are frequently detected in humans as important ingredients of plastic products. However, patterns of exposure to harmful ingredients of plastics and their effects on neurofilament light chain (NFL), a marker of active brain pathology, are currently inconclusive. Herein, we employed a range of statistical methods to thoroughly investigate the impact of 24 plastic hazardous ingredients and their varying exposure patterns on NFL concentrations in the blood of the general population in 533 participants. Generalized linear model revealed a positive correlation between Mono-isononyl phthalate and Mono (2-Ethyl- 5-Hydroxyhexyl) Phthalate (MEHHP) with NFL. Furthermore, a significant dose-response relationship was observed between MEHHP and NFL, while Butyl paraben and Mono (Hydroxy-Isononyl) Ester exhibited a distinct "inverted U-shaped" nonlinear pattern with NFL. Additionally, Weighted Quantile Sum model allowed us to identify the mixed effects of all 24 plastic hazardous ingredients, with Mono(2-Ethyl-5-Oxohexyl) Phthalate, Mono-isobutyl phthalate, Mon butyl Phthalate, Propyl paraben and Triclosan occupying prominent positions. Finally, the latent profile analysis categorized exposures into high, medium, and low patterns, confirming that higher exposure to plastic hazardous ingredients posed a significant risk factor for elevated NFL levels in the blood. Exposure to plastic hazardous ingredients significantly increases the risk of NFL, the present contributes to early detection and intervention to reduce the incidence of neurodevelopmental disorder.

Phthalate exposures, blood coagulation function, and assisted reproductive technology outcomes: Results from the TREE cohort study

BACKGROUND

Phthalate exposures have been shown to be inversely associated with reproductive success among women undergoing assisted reproductive technology (ART). However, the underlying mechanisms are unknown.

OBJECTIVES

To explore blood coagulation function as the mediating role of associations between exposure to phthalates and ART outcomes.

METHODS

A total of 735 women from the Tongji Reproductive and Environmental (TREE) study were included. Urine samples collected at recruitment were quantified for 8 phthalate metabolites, and blood clotting time and platelet indices were also determined. Generalized linear regression, logistic regression, weighted quantile sum (WQS) regression, or Bayesian kernel machine regression (BKMR) models were applied to investigate the associations among individual and mixture of phthalate metabolites, blood coagulation parameters, and ART outcomes. The mediation role of blood coagulation parameters was estimated by mediation analysis.

RESULTS

Mono-n-butyl phthalate (MBP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), and molar sum of di(2-ethylhexyl) phthalate metabolites (∑DEHP) were positively associated with platelet indices. Phthalate metabolite mixture was also positively associated with platelet count (PLT), mean platelet volume (MPV), and plateletcrit (PCT), whereas inversely associated with international normalized ratio (INR). Meanwhile, PLT and PCT were inversely associated with the odds of implantation success and live birth, while prothrombin time and INR were positively associated with the odds of implantation success. Mediation analyses showed indirect effects of above-mentioned phthalate metabolites and phthalate mixture on the odds of implantation success and live birth through PLT or PCT, with the proportion mediated ranging from 3.44% to 8.96%.

CONCLUSIONS

Phthalates may increase the risks of ART failure through enhancing blood coagulation function. More studies are warranted to verify the findings.

Mechanistic insight of neurodegeneration due to micro/nano-plastic-induced gut dysbiosis

Despite offering significant conveniences, plastic materials contribute substantially in developing environmental hazards and pollutants. Plastic trash that has not been adequately managed may eventually break down into fragments caused by human or ecological factors. Arguably, the crucial element for determining the biological toxicities of plastics are micro/nano-forms of plastics (MPs/NPs), which infiltrate the mammalian tissue through different media and routes. Infiltration of MPs/NPs across the intestinal barrier leads to microbial architectural dysfunction, which further modulates the population of gastrointestinal microbes. Thereby, it triggers inflammatory mediators (e.g., IL-1α/β, TNF-α, and IFN-γ) by activating specific receptors located in the gut barrier. Mounting evidence indicates that MPs/NPs disrupt host pathophysiological function through modification of junctional proteins and effector cells. Moreover, the alteration of microbial diversity by MPs/NPs causes the breakdown of the blood-brain barrier and translocation of metabolites (e.g., SCFAs, LPS) through the vagus nerve. Potent penetration affects the neuronal networks, neuronal protein accumulation, acceleration of oxidative stress, and alteration of neurofibrillary tangles, and hinders distinctive communicating pathways. Conclusively, alterations of these neurotoxic factors are possibly responsible for the associated neurodegenerative disorders due to the exposure of MPs/NPs. In this review, the hypothesis on MPs/NPs associated with gut microbial dysbiosis has been interlinked to the distinct neurological impairment through the gut-brain axis.

Phthalates exposure, biological aging, and increased risks of insulin resistance, prediabetes, and diabetes in adults with metabolic dysfunction-associated steatotic liver disease

AIM

To estimate the individual and combined influences of phthalates and biological aging on insulin resistance (IR), prediabetes, and diabetes in population with metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

Data on 3,045 US adults with MASLD were collected to outline the individual and mixed effects of urinary phthalate metabolites on prevalent IR, prediabetes, and diabetes by survey-weighted logistic regression and weighted quantile sum (WQS) regression, as well as the interaction effects between phthalates and biological aging.

RESULTS

We discovered positive relationships - odds ratio (OR) and 95 % confidence interval [CI] - of mono-2-ethyl-5-carboxypentyl phthalate 1.147 [1.041;1.264], mono-(2-ethyl-5-hydroxyhexyl) phthalate 1.175 [1.073;1.288], and mono-(2-ethyl-5-oxohexyl) phthalate 1.140 [1.040;1.250] with IR, and of mono-isobutyl phthalate with prediabetes 1.216 [1.064;1.390] (all FDR-adjusted P < 0.05). WQS analyses indicated significantly mixed effects of phthalate metabolites on the elevated risks of IR 1.166 [1.034;1.315], prediabetes 1.194 [1.006;1.416], and diabetes 1.214 [1.026;1.437]. Biological age (BA) and phenotypic age (PA) were positively associated with IR, prediabetes, and diabetes and further significantly interacted with phthalates on the outcomes; typically, compared to participants with low levels of phthalates mixture and PA, those with high levels of phthalates mixture and PA had the highest risks of IR 2.468 [1.474;4.133] (Pinteraction = 0.031), prediabetes 1.975 [1.189;3.278] (Pinteraction = 0.009), and diabetes 6.065 [3.210;11.460] (Pinteraction = 0.013).

CONCLUSION

Phthalates exposure of MASLD adults was related to increased risks of IR, prediabetes, and diabetes, which were interactively aggravated by biological aging. Controlling phthalates exposure and biological aging probably hold significant relevance for the prevention of diabetes in the MASLD population.

Analysis of Plasticizer Contamination Throughout Olive Oil Production

This study monitored the contamination of 32 plasticizers in olive oil throughout the production and storage process. Samples were collected at different stages of production from three olive oil production lines in distinct regions of Portugal and analyzed for 23 phthalates and 9 phthalates substitutes to identify contamination sources. The developed analytical method employed liquid-liquid extraction with hexane/methanol (1:4, v/v), followed by centrifugation, extract removal, and freezing as a clean-up step. Analysis was conducted using gas chromatography tandem mass spectrometry (GC-MS/MS), with detection limits ranging from 0.001 to 0.103 mg/kg. The results revealed that plasticizer concentrations progressively increased at each stage of the production process, although unprocessed olives also contained contaminants. Di-isononyl phthalate (DINP) was the most prevalent compound, but all phthalates regulated by the European Union for food contact materials were detected, as well as some unregulated plasticizers. In a few packaged olive oils, DINP concentrations exceeded the specific migration limits established by European regulations. Samples stored in glass and plastic bottles showed no significant differences in plasticizer concentrations after six months of storage. However, higher concentrations were observed in plastic-packaged samples after 18 months of storage. Our findings indicate that the primary source of plasticizer contamination in olive oil originates from the production process itself, except for prolonged storage in plastic bottles, which should be avoided.

Tracking chemical feature releases from plastic food packaging to humans

Humankind are being exposed to a cocktail of chemicals, such as chemicals released from plastic food packaging. It is of great importance to evaluate the prevalence of plastic food packaging-derived chemicals pollution along the flow of food-human. We developed a robust and practical database of 2101 chemical features associated with plastic food packaging that combined data from three sources, 925 of which were acquired from non-target screening of chemical extracts from eight commonly used plastic food packaging materials. In this database, 625 features, especially half of the non-targets, were potential migrants who likely entered our bodies through dietary intake. Biomonitoring analysis of plastic chemical features in foodstuffs or human serum samples showed that approximately 78 % of the 2101 features were detectable and approximately half were non-targets. Of these, 17 plastic chemicals with high detection frequencies (DFs) in the human serum were confirmed to be functional chemical additives. Together, our work indicates that the number of plastic chemicals in our bodies could be far greater than previously recognized, and human exposure to plastic chemicals might pose a potential health risk.

Adolescent urinary concentrations of phthalate metabolites and indices of overweight and cardiovascular risk in Dutch adolescents

Phthalates have been linked to cardiovascular risk factors. Exposure to chemicals with endocrine disrupting properties during the pubertal period can interfere with normal endocrine processes. This study aims to determine whether adolescent urinary concentrations of phthalate metabolites are associated with indices of overweight and cardiovascular risk in 13-15-year-old children. In this Dutch observational cross-sectional cohort study, 101 adolescents were included (mean age 14.4 ± 0.8 years), 55 were boys. The concentrations of 13 phthalate metabolites were measured in morning urine samples. Levels of cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDL-C), triglycerides, fasting insulin, fasting glucose, leptin, and adiponectin were measured. The children's height, weight, waist circumference, hip circumference, and blood pressure were measured. Higher urinary mono-ethyl phthalate concentrations were associated with higher BMI and a larger hip circumference. In girls, higher urinary mono-hydroxy-iso-nonyl phthalate concentrations were associated with higher levels of lipids and obesogenic traits. In boys, higher concentrations of urinary phthalate metabolites were associated with lower LDL-C. The results of this explorative study suggest that higher levels of phthalate metabolites are associated with higher levels of lipids and obesogenic traits in 13-15-year-old girls.

Fusarium as a promising fungal genus with potential application in bioremediation for pollutants mitigation: A review

Fusarium is genetically diverse and widely distributed geographically. It is one of the genera with more endophytes (which cause no damage to the host plants). This review highlights the capability of Fusarium species to degrade environmental pollutants and describes the biodegradation pathways of some of the emerging environmental contaminants. Some Fusarium species use metabolic strategies enabling them to efficiently mineralize high concentrations of toxic environmental pollutants. These fungi can degrade hydrocarbons, pesticides, herbicides, dyes, pharmaceutical compounds, explosives, plastics, and plastic additives, among other pollutants, and possess high metal biosorption capabilities. According to data from consulted reports, Fusarium strains showed a percentage of biodegradation of a variety of contaminants ranging between 30 % and 100 % for different tested concentrations (from 1 mg to 10 g/L) in a time range between 10 h and 90 d. Enzymes such as esterase, cutinase, laccase, lignin peroxidase, manganese peroxidase, dehydrogenase, lipase, dioxygenase, and phosphoesterase were detected during the pollutant biodegradation process. Fusarium oxysporum, Fusarium solani, and Fusarium culmorum are the most studied species of this genus. Owing to their metabolic versatility, these fungal species and their enzymes represent promising tools for bioremediation applications to mitigate the adverse effects of environmental pollution.

Associating prenatal phthalate exposure with childhood autistic traits: Investigating potential adverse outcome pathways and the modifying effects of maternal vitamin D

The association between prenatal phthalate mixture exposure and the risk of autism spectrum disorder (ASD) in children, as well as the potential mechanism and impact of maternal vitamin D, remains unclear. We analyzed data from 3209 mother-child pairs. The associations between prenatal phthalate exposure and autistic traits in children aged 1.5, 3, 5, and 6 years were explored. Furthermore, the modifying effects of maternal vitamin D and the adverse outcome pathway, which elucidates the contribution of phthalates to ASD, were estimated. Exposure to a phthalate mixture was associated with an increased risk of ASD in children aged 1.5-6 years. For mothers with 25(OH)D deficiency, an exposure‒response relationship was observed between phthalate mixtures in early to mid-pregnancy and autistic traits in children aged 3 years. However, this association was not observed for mothers with sufficient prenatal 25(OH)D levels. The potential mechanism of action of di(2-ethylhexyl) phthalate (DEHP) exposure may involve affecting GRIN2B, inhibiting NMDAR in the postsynaptic membrane, disrupting synaptic function, and impairing learning and memory, ultimately leading to ASD development. Importantly, maternal vitamin D supplementation was demonstrated to mitigate the risk of ASD associated with phthalate exposure. Reducing phthalate exposure during pregnancy may be associated with a decreased risk of autistic traits in children. Furthermore, adequate vitamin D supplementation could potentially mitigate the impact of phthalates on these traits. Additionally, the proposed biological mechanism provides insight into how phthalate exposure may contribute to the development of ASD.

Effects of di-(2-ethylhexyl) phthalate and its metabolites on transcriptional activity via human nuclear receptors and gene expression in HepaRG cells

Di-(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer in polyvinyl chloride products. DEHP exposure in humans is of great concern due to its endocrine-disrupting properties. In this study, we characterized the agonistic activities of DEHP and its five metabolites, mono-(2-ethylhexyl) phthalate (MEHP), 5OH-MEHP, 5oxo-MEHP, 5cx-MEPP and 2cx-MMHP against human nuclear receptors, peroxisome proliferator-activated receptor α (PPARα), pregnane X receptor (PXR), and constitutive androstane receptor (CAR) using transactivation assays. In the PPARα assay, the order of the agonistic activity was MEHP >> 5cx-MEPP >5OH-MEHP, 5oxo-MEHP >2cx-MMHP > DEHP, with DEHP significantly inhibiting MEHP-induced PPARα agonistic activity. This finding was compared to the results from in silico docking simulation. In the PXR assay, DEHP showed PXR agonistic activity more potent than that of MEHP, whereas the other metabolites showed little activity. In the CAR assay, none of the tested compounds showed agonistic activity. Moreover, the expression levels of PPARα-, PXR-, and CAR-target genes in HepaRG cells exposed to DEHP or MEHP were investigated using qRT-PCR analysis. As a result, exposure to these compounds significantly upregulated PXR/CAR target genes (CYP3A4 and CYP2B6), but not PPARα target genes (CYP4A11, etc.) in HepaRG cells. Taken together, these results suggest that direct PXR and/or indirect CAR activation by several DEHP metabolites may be involved in the endocrine disruption by altering hormone metabolism.

Di-(2-ethylhexyl) phthalate induces prepubertal testicular injury through MAM-related mitochondrial calcium overload in Leydig and Sertoli cell apoptosis

As one of the most prevalent environmental endocrine disruptors, di-(2-ethylhexyl) phthalate (DEHP) is known for its significant developmental toxicity to the male reproductive system in humans and mice. Prepubertal exposure to DEHP has been shown to cause testicular damage, but the underlying mechanisms require further investigation. To investigate this effect, prepubertal mice were exposed to 100, 250 or 500 mg/kg body weight (bw) of DEHP for 14 days, which resulted in impaired histological structure and increased apoptosis of the testes. RNA sequencing (RNA-seq) of testicular tissue suggested that DEHP led to injury in Leydig and Sertoli cells. To further elucidate these mechanisms, we conducted experiments using immature mouse Leydig (TM3) and Sertoli (TM4) cells, and exposed them to 200 μM mono-(2-ethylhexyl) phthalate (MEHP), the primary metabolite of DEHP, for 24 h. We found that MEHP exposure induced oxidative stress injury and promoted cell apoptosis, and that cotreatment with N-acetylcysteine partially reversed these injuries. Given the close association between oxidative stress and mitochondrial calcium levels, we demonstrated that MEHP exposure disrupted mitochondria and increased mitochondrial calcium levels. In addition, MEHP exposure facilitated the formation of mitochondria-associated endoplasmic reticulum membranes (MAMs), upregulated protein expression and enhanced the interactions of the IP3R3-Grp75-VDAC1 complex. Furthermore, inhibition of calcium transfer in the IP3R3-Grp75-VDAC1-MCU axis relieved MEHP-induced mitochondrial injury, oxidative stress and apoptosis in TM3 and TM4 cells. This study highlights the importance of MAM-mediated mitochondrial calcium overload and the subsequent apoptosis of Leydig and Sertoli cells as pivotal factors contributing to testicular injury induced by prepubertal exposure to DEHP.

Resveratrol alleviates Mono-2-ethylhexyl phthalate-induced mitophagy, ferroptosis, and immunological dysfunction in grass carp hepatocytes by regulating the Nrf2 pathway

Mono-2-ethylhexyl phthalate (MEHP) is the major biologically active metabolite of Di(2-ethylhexyl) phthalate (DEHP). This MEHP mono-ester metabolite can be transported through the bloodstream into tissues such as the liver, kidneys, fat, and testes and cause corresponding damage. Resveratrol (RSV) has anti-inflammatory, antioxidant, and detoxification characteristics. Our research examined whether RSV alleviates MEHP-induced grass carp hepatocyte (L8824 cell) injury and its relationship with the Nrf2 pathway, mitophagy, ferroptosis, and immune function. Therefore, we treated L8824 cells with 85 μM MEHP and/or 2 μM RSV. The findings indicated that exposing MEHP resulted in increased reactive oxygen species (ROS) content and decreased mitochondrial membrane potential in L8824 cells, which induced an up-regulation of the expression of mitophagy-related indicators (PINK1, Parkin, Beclin1, LC3B, and ATG5) and a down-regulation of P62. An up-regulation of the expression of the ferroptosis-related indicators TFR1 and COX-2, and GPX4 and FTH expression was down-regulated. In addition, there was a decrease in the expression of IL-2 and IFN-γ and an increase in the expression of inflammatory cytokines such as TNF-α, IL-1β, and IL-6 after exposure to MEHP. RSV activates the Nrf2 pathway and effectively alleviates MEHP-induced mitophagy, ferroptosis, and immunologic dysfunction of L8824 cells.

Phthalate exposure increases oxidative stress, early renal injury, and the risk of calcium urolithiasis: A case-control study

BACKGROUND

Phthalates, ubiquitous in plastics and softening agents, are pervasive in our daily environment. Growing concerns have emerged regarding their potential impact on renal health, particularly due to their propensity to induce oxidative stress. However, the relationship between phthalate exposure and urolithiasis remains poorly understood. This research seeks to explore the connection between phthalate exposure, oxidative stress, and the risk of urolithiasis.

METHODS

A case-control study involving 285 patients diagnosed with calcium urolithiasis and 594 healthy controls was conducted. Participants completed structured questionnaires and provided urine samples for measuring 10 phthalate metabolites, biomarkers of oxidative stress (malondialdehyde [MDA]) and early renal injury (N-acetyl-beta-D-glucosaminidase [NAG] and albumin/creatinine ratio [ACR]). For subsequent analyses, we utilized distinct categories: the sum of high-molecular-weight phthalate metabolites (∑HMWm), the sum of low-molecular-weight phthalate metabolites (∑LMWm), and the daily intake of di-2-ethylhexyl phthalate (DEHP)(DI_DEHP_5).

RESULTS

Stone patients exhibited significantly elevated urinary biomarkers of oxidative stress (MDA) and early renal injury (NAG and ACR), along with higher levels of 9 out of 10 assessed phthalate metabolites compared to normal controls. Within the study population, significant positive associations were found between almost all individual phthalate metabolites and urinary biomarkers of oxidative stress (MDA) as well as early renal injury (NAG and ACR). Logistic regression further confirmed that elevated phthalate levels, including ∑HMWm, ∑LMWm, and DI_DEHP_5, were uniformly associated with an increased risk of oxidative stress, early renal injury, and urolithiasis after adjusting for confounding factors.

CONCLUSIONS

Our study uncovers a novel association between phthalate exposure and the risk of urolithiasis, underscoring the heightened risk of kidney injury posed by such exposure. Considering the widespread presence of phthalates, regulatory measures and public health interventions are crucial to mitigate phthalate-related nephrotoxicity, while further large-scale longitudinal research is imperative to validate our initial findings and elucidate the underlying mechanisms.

Associations of exposure to phthalate with serum uric acid and hyperuricemia risk, and the mediating role of systemic immune inflammation

BACKGROUND

Previous studies found that urinary phthalates (PAEs) metabolites may be associated with increased serum uric acid concentration and hyperuricemia risk. However, no population-based study has investigated the underlying biological mechanisms.

METHODS

This nationwide cross-sectional study analyzed the data from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Urinary PAEs metabolites were measured and 8 PAEs metabolites (MCPP, MECPP, MEHHP, MEOHP, MBzP, MiBP, MBP, and MEP) were incorporated into the analysis. Serum uric acid was determined and hyperuricemia cases were identified. Multi-variable generalized linear model, exposure-response (E-R) function and weighted quantile sum (WQS) regression were utilized to investigate the relationships of PAEs metabolites with serum uric acid concentration and hyperuricemia risk. Systemic immune inflammation (SII) was assessed using the SII index and its mediation effects were explored using causal mediation effect model.

RESULTS

Data from 10,633 US adults in the NHANES 2003-2018 was analyzed. Except for MEP, individual PAEs metabolite and total PAEs metabolites were associated with increased serum uric acid concentration and hyperuricemia risk. E-R function of PAEs metabolites with serum uric acid concentration and the risk of hyperuricemia showed significantly positive associations with most curves in a nearly linear relationship. WQS regression showed that the mixture of PAEs metabolites was related to elevated serum uric acid and hyperuricemia risk, and MBzP was identified as the most contributing PAEs metabolite. The causal mediation effect model found that SII significantly mediated the relationships of PAEs metabolites with serum uric acid and hyperuricemia risk.

CONCLUSION

Individual and mixture of urinary PAEs metabolites were associated with increased serum uric acid concentration and the risk of hyperuricemia. MBzP exhibited the highest contribution to the overall effects. SII alteration may be an important biological mechanism underlining the impact of PAEs metabolites on serum uric acid concentration and hyperuricemia risk.

piRNA array analysis provide insight into the mechanism of DEHP-induced testicular toxicology in pubertal male rats

Di-(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer, could cause male reproductive toxicity by disrupting spermatogenesis. Piwi-interacting RNAs (piRNAs) are a small non-coding RNAs specifically highly expressed in the germline and interact with PIWI proteins to regulate spermatogenesis. Accumulating studies have confirmed that environmental poisons could induce male reproductive injury via altering piRNA expression. However, it remains unclear whether DEHP causes male reproductive dysfunction by perturbing piRNA expression levels. In this study, we conducted piRNA microarray expression analyses on testes of DEHP-exposed and control male rats and performed some in vitro and in vivo studies to explore the role of piRNA on DEHP-induced male reproductive toxicity. Our results showed that DEHP exposure leaded to changed expression profiles of piRNAs in pubertal male rat testes. And bioinformatics analyses revealed that down-regulated piR-rno-26751 probably targeted Insr mRNA expression regulation. Results from gene and protein expression tests demonstrated that DEHP caused decreased expression level of INSR mainly in spermatogonia. Moreover, MEHP, the main metabolite of DEHP resulted in cell apoptosis and down-regulation of INSR and its downstream p-IRS1, p-PI3K, p-AKT and p-FOXO1 in GC-1spg cells. Conversely, overexpression of INSR restored cell apoptosis and the down-regulation of the above proteins in GC-1spg cells. In conclusion, these findings suggest that DEHP-induced down-regulation of piR-rno-26751 targets the suppression of INSR, leading to apoptosis of spermatogonia in pubertal male rats.

Environmental endocrine disrupting chemical-DEHP exposure-provoked biotoxicity about microbiota-gut-mammary axis in lactating mice via multi-omics technologies

Plastics, pervasive in humans and nature, often contain Di (2-ethylhexyl) phthalate (DEHP) that enhance plastic's elasticity. However, DEHP is an environmental endocrine disruptor, affecting organisms upon exposure. Understanding mammary gland development in lactating females is crucial for offspring nourishment and dairy production. Employing multi-omics technology, this study aimed to uncover DEHP's impact on the microbial-gut-mammary axis. Forty mice were exposed to varying DEHP doses for 18 d. We performed 16S sequencing, metabolomics, mammary tissue observation, and gene expression profiling. Results revealed DEHP's influence on microbial diversity, with increased Lactobacillus abundance and reduced Proteobacteria, alongside colonic inflammation. Elevated GMP and adenosine 5'-monophosphate levels in the bloodstream were noted, while ascorbic acid, glycitein, and others decreased. MEHP, a DEHP metabolite, damaged mammary tissues, inhibiting ERK1/2 phosphorylation, triggering apoptosis and ferroptosis. These findings unveil potential therapeutic targets for DEHP-induced chronic toxicity in humans and animals, aiding dairy livestock health and human well-being. This study underscores the importance of understanding the adverse effects of DEHP exposure on mammalian systems.

Placental Transcriptomic Signatures of Prenatal Phthalate Exposure and Identification of Placenta-Brain Genes Associated with the Effects of Phthalate Exposure on Neurodevelopment in Children

Prenatal exposure to phthalates may affect placental function and fetal development, but the underlying mechanisms are unclear. The aim of our study was to explore the alterations in the placental transcriptome associated with prenatal phthalate exposure and to further analyze whether the placental-brain axis (PBA) genes play a mediating role in the association between prenatal phthalate exposure and children's neurodevelopment. We included 172 participants from the Ma'anshan Birth Cohort and collected data on seven phthalate metabolites in urine during pregnancy, placental tissue RNA-seq, and neurodevelopment of offspring. Bioinformatics analysis revealed that aberrant regulation of the placental transcriptome was associated with prenatal phthalate exposure. Exposure to phthalates during pregnancy was found to be associated with neurodevelopmental delay in children aged 6, 18, and 48 months using the multiple linear regression model. Meanwhile, employing mediation analysis, nine PBA genes were identified that mediate the association between exposure to phthalates during pregnancy and the neurodevelopment of children. Our study will provide a basis for potential mechanisms by which prenatal exposure to phthalates affects placental function and children's neurodevelopment.

Androgen blockage impairs proliferation and function of Sertoli cells via Wee1 and Lfng

BACKGROUND

Androgens are essential hormones for testicular development and the maintenance of male fertility. Environmental factors, stress, aging, and psychological conditions can disrupt androgen production, impacting the androgen signaling pathway and consequently spermatogenesis. Within the testes, testosterone is produced by Leydig cells and acts on Sertoli cells by activating the androgen receptor (AR), which then translocates to the nucleus to function as a transcription factor. Despite clinical correlations between low testosterone levels and diminished sperm quality, the precise mechanism remains unclear.

METHODS

This study explores the hypothesis that reduced androgen levels impair Sertoli cell function by disrupting AR transcriptional regulation. Using an androgen blockade model with enzalutamide, we investigated the impact of low androgen levels on AR target genes in Sertoli cells through ChIP-seq and RNA-seq assays.

RESULTS

Our results reveal that androgen blockage increases AR enrichment on the promoter region of Wee1, promoting Wee1 expression, while decreasing binding to the promoter region of Lfng, inhibiting its expression. Increased WEE1 protein inhibits Sertoli cell proliferation, whereas reduced LFNG affects Notch modification, leading to decreased production of glial cell line-derived neurotrophic factor (GDNF), a key growth factor for spermatogonial stem cell self-renewal.

CONCLUSIONS

These findings provide new insights into the molecular mechanisms by which low androgen levels interfere with Sertoli cell functions, offering novel perspectives for the clinical treatment of male reproductive disorders.

Maternal symptoms of depression and anxiety as modifiers of the relationship between prenatal phthalate exposure and infant neurodevelopment in the Atlanta African American maternal-child cohort

Background

Prenatal exposure to phthalates, a group of synthetic chemicals widely used in consumer products, has previously been associated with adverse infant and child development. Studies also suggest that maternal depression and anxiety, may amplify the harmful effects of phthalates on infant and child neurodevelopment.

Study design

Our analysis included a subset of dyads enrolled in the Atlanta African American Maternal-Child Cohort (N = 81). We measured eight phthalate metabolites in first and second trimester (8-14 weeks and 24-32 weeks gestation) maternal urine samples to estimate prenatal exposures. Phthalate metabolite concentrations were averaged across visits and natural log-transformed for analysis. Maternal symptoms of depression and anxiety were assessed using validated questionnaires (Edinberg Postnatal Depression Scale and State Trait Anxiety Inventory, respectively) and the total score on each scale was averaged across study visits. The NICU Network Neurobehavioral Scale (NNNS) was administered at two weeks of age. Our primary outcomes included two composite NNNS scores reflecting newborn attention and arousal. Linear regression was used to estimate associations between individual phthalate exposures and newborn attention and arousal. We assessed effect modification by maternal depression and anxiety.

Results

Higher levels of urinary phthalate metabolites were not associated with higher levels of infant attention and arousal, but true associations may still exist given the limited power of this analysis. In models examining effect modification by maternal depression, we observed that an interquartile range increase in mono (2-ethlyhexyl) phthalate (MEHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was associated with a significant increase in newborn arousal only among those with high depressive symptoms (MEHP: β = 0.71, 95% confidence interval [CI] = 0.10, 1.32 for high, β = -0.30, 95% CI = -0.73, 0.12 for low; MEOHP: β = 0.60, 95% CI = -0.03, 1.23 for high, β = -0.12, 95% CI = -0.58, 0.33 for low; MEHHP: β = 0.54, 95% CI = -0.04, 1.11 for high, β = -0.11, 95% CI = -0.54, 0.32 for low). Similar patterns were observed in models stratified by maternal anxiety, although CIs were wide.

Conclusion

Our results suggest maternal anxiety and depression symptoms may exacerbate the effect of phthalates on infant neurodevelopment. Future studies are needed to determine the optimal levels of attention and arousal in early infancy.

Silicone wristbands reveal ubiquitous human exposure to ortho-phthalates and non-ortho-phthalate plasticizers in Southern California

In the United States and abroad, ortho-phthalates and non-ortho-phthalate plasticizers continue to be used within a diverse array of consumer products. Prior California-specific biomonitoring programs for ortho-phthalates have focused on rural, agricultural communities and, to our knowledge, these programs have not measured the potential for exposure to non-ortho-phthalate plasticizers. Therefore, the potential for human exposure to ortho-phthalates and non-ortho-phthalate plasticizers have not been adequately addressed in regions of California that have higher population density. Since there are numerous sources of ortho-phthalates and non-ortho-phthalate plasticizers in population-dense, urban regions, the objective of this study was to leverage silicone wristbands to quantify aggregate ortho-phthalate and non-ortho-phthalate plasticizer exposure over a 5-day period across two different cohorts (2019 and 2020) of undergraduate students at the University of California, Riverside (UCR) that commute from all over Southern California. Based on 5 d of aggregate exposure across two different cohorts, total ortho-phthalate plus non-ortho-phthalate plasticizer concentrations ranged, on average, from ∼100,000-1,000,000 ng/g. Based on the distribution of individual ortho-phthalate and non-ortho-phthalate plasticizer concentrations, the concentrations of di-isononyl phthalate (DiNP, a high molecular weight ortho-phthalate), di (2-ethylhexyl) phthalate (DEHP, a high molecular weight ortho-phthalate), and di-2-ethylhexyl terephthalate (DEHT, a non-ortho-phthalate plasticizer) detected within wristbands were higher than the remaining seven ortho-phthalates and non-ortho-phthalate plasticizers measured, accounting for approximately 94-97% of the total mass depending on the cohort. Overall, our findings raise concerns about chronic DiNP, DEHP, and DEHT exposure in urban, population-dense regions throughout California.

Photoaging enhances the leaching of di(2-ethylhexyl) phthalate and transformation products from polyvinyl chloride microplastics into aquatic environments

Increasing chemical pollution is a threat to sustainable water resources worldwide. Plastics and harmful additives released from plastics add to this burden and might pose a risk to aquatic organisms, and human health. Phthalates, which are common plasticizers and endocrine-disrupting chemicals, are released from polyvinyl chloride (PVC) microplastics and are a cause of concern. Therefore, the leaching kinetics of additives, including the influence of environmental weathering, are key to assessing exposure concentrations but remain largely unknown. We show that photoaging strongly enhances the leaching rates of di(2-ethylhexyl) phthalate (DEHP) by a factor of 1.5, and newly-formed harmful transformation products, such as mono(2-ethylhexyl) phthalate (MEHP), phthalic acid, and phthalic anhydride from PVC microplastics into the aquatic environment. Leaching half-lives of DEHP reduced from 449 years for pristine PVC to 121 years for photoaged PVC. Aqueous boundary layer diffusion (ABLD) is the limiting mass transfer process for the release of DEHP from pristine and photoaged PVC microplastics. The leaching of transformation products is limited by intraparticle diffusion (IPD). The calculated mass transfer rates can be used to predict exposure concentrations of harmful additives in the aquatic environment.

Widespread phthalate esters and monoesters in the aquatic environment: Distribution, bioconcentration, and ecological risks

Field research on phthalate monoesters (MPEs) and their relationships with phthalate esters (PAEs) is limited, especially in wild fishes. Here, PAEs and MPEs were measured in surface water, sediment, and wild fish collected from a representative river basin with high economic development. Several metabolites of emerging plasticizers, such as mono(3,5,5-trimethyl-1-hexyl) phthalate and mono(6-oxo-2-propylheptyl) phthalate, have already existed in fish with high detection frequencies (95 % and 100 %). Monobutyl phthalate and mono(2-ethylhexyl) phthalate were the predominant MPEs in fish and natural environment (surface water and sediment), while bis(2-ethylhexyl) phthalate was the most abundant PAEs in all matrices. The total concentrations (median) of 9 PAEs and 16 MPEs were 5980 and 266 ng/L in water, 231 and 10.6 ng/g (dw) in sediment, and 209 and 32.5 ng/g (ww) in fish, respectively. The occurrence of MPEs was highly related to their parent PAEs, with similar spatial distribution characteristics in the aquatic environments. Moreover, municipal wastewater discharge was recognized as the main source of MPEs in the research area. Fish species can accumulate targeted chemicals, and it seems more MPEs were from the PAE degradation in fish other than the direct uptake of MPEs in water. Parent PAEs showed higher ecological risk than their corresponding metabolites.

Identification and quantification of acetyl tributyl citrate (ATBC) metabolites using human liver microsomes and human urine

Plasticizers are chemicals that make plastics flexible, and phthalates are commonly used. Due to the toxic effects of phthalates, there is increasing use of non-phthalate plasticizers like acetyl tributyl citrate (ATBC). ATBC has emerged as a safer alternative, yet concerns about its long-term safety persist due to its high leachability and potential endocrine-disrupting effects. This study aims to identify ATBC metabolites using human liver microsomes and suspect screening methods, and to explore potential urinary biomarkers for ATBC exposure. Using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry, we identified ATBC metabolites, including acetyl dibutyl citrate (ADBC), tributyl citrate (TBC), and dibutyl citrate (DBC). Urine samples from 15 participants revealed the presence of ADBC in 5, TBC in 11, and DBC in all samples, with DBC concentrations pointedly higher than the other metabolites. These metabolites show promise as biomarkers for ATBC exposure, though further validation with human data is required. Our results underscore the need for comprehensive studies on ATBC metabolism, exposure pathways, and urinary excretion to accurately assess human exposure levels.

Health hazards of preconception phthalate exposure: A scoping review of epidemiology studies

There is a close relationship between preconception health and maternal and child health outcomes, and the consequences may be passed down from generation to generation. In 2018, Lancet published three consecutive articles emphasizing the importance of the preconception period. Phthalic acid ester (PAE) exposure during this period may affect gametogenesis and epigenetic information in gametophytes, thereby affecting embryonic development and offspring health. Therefore, this article reviews the effects of parental preconception PAE exposure on reproductive/birth outcomes and offspring health, to provide new evidence on this topic. We searched Web of Science, MEDLINE (through PubMed), the China National Knowledge Infrastructure (CNKI), ScienceDirect, and the VIP Journal Library from the date of database establishment to July 3, 2024. Finally, 12 articles were included. Three studies investigated the health hazards (effects on birth weight, abortion, etc.) of women's preconception PAE exposure. Nine studies involved both parents. Nine studies considered the impacts of PAE preconception exposure on reproductive/birth outcomes, focusing on birth weight, pregnancy loss, preterm birth, embryo quality, and placental weight. Three studies considered the impacts of preconception PAE exposure on offspring behavior. The results of this review suggested that parental preconception PAE exposure may have an impact on reproductive/birth outcomes and offspring behavior, including birth weight, child behavior, and dietary behavior. However, studies on the health hazards of preconception PAE exposure are relatively scarce, and the outcomes of current studies are varied. It is necessary to use systematic reviews to verify an accurate research question to provide recommendations for public health policy making.

Association between the Exposure to Phthalates and the Risk of Endometriosis: An Updated Review

Endometriosis is a chronic gynecological disease, primarily associated with pelvic pain and infertility, that affects approximately 10% of the women of reproductive age. Estrogen plays a central role in endometriosis, and there is growing evidence that endocrine disruptors, such as phthalates, may contribute to its development. This review aimed to determine whether there is a causal relationship between phthalate exposure and the development of endometriosis, as well as the possible effects of phthalates on fertility, by analyzing epidemiological data. After a literature search with a combination of specific terms on this topic, we found that although there are limitations to the current studies, there is a clear association between phthalate exposure and endometriosis. Phthalates can interfere with the cellular processes of the endometrium; specifically, they can bind to PPAR and ER-α and activate TGF-β, promoting different signaling cascades that regulate the expression of specific target genes. This may lead to inflammation, invasion, cytokine alteration, increased oxidative stress, and impaired cell viability and proliferation, culminating in endometriosis. Nevertheless, future research is important to curb the progression and development of endometriosis, and strategies for prevention, diagnosis, and treatment are a priority. In this regard, public policies and recommendations to reduce exposure to phthalates and other endocrine disruptors should be promptly implemented.

An Umbrella Review of Meta-Analyses Evaluating Associations between Human Health and Exposure to Major Classes of Plastic-Associated Chemicals

Background: Epidemiological research investigating the impact of exposure to plastics, and plastic-associated chemicals, on human health is critical, especially given exponentially increasing plastic production. In parallel with increasing production, academic research has also increased exponentially both in terms of the primary literature and ensuing systematic reviews with meta-analysis. However, there are few overviews that capture a broad range of chemical classes to present a state of play regarding impacts on human health. Methods: We undertook an umbrella review to review the systematic reviews with meta-analyses. Given the complex composition of plastic and the large number of identified plastic-associated chemicals, it was not possible to capture all chemicals that may be present in, and migrate from, plastic materials. We therefore focussed on a defined set of key exposures related to plastics. These were microplastics, due to their ubiquity and potential for human exposure, and the polymers that form the matrix of consumer plastics. We also included plasticisers and flame retardants as the two classes of functional additive with the highest concentration ranges in plastic. In addition, we included bisphenols and per- and polyfluoroalkyl substances (PFAS) as two other major plastic-associated chemicals with significant known exposure through food contact materials. Epistemonikos and PubMed were searched for systematic reviews with meta-analyses, meta-analyses, and pooled analyses evaluating the association of plastic polymers, particles (microplastics) or any of the selected groups of high-volume plastic-associated chemicals above, measured directly in human biospecimens, with human health outcomes. Results: Fifty-two systematic reviews were included, with data contributing 759 meta-analyses. Most meta-analyses (78%) were from reviews of moderate methodological quality. Across all the publications retrieved, only a limited number of plastic-associated chemicals within each of the groups searched had been evaluated in relevant meta-analyses, and there were no meta-analyses evaluating polymers, nor microplastics. Synthesised estimates of the effects of plastic-associated chemical exposure were identified for the following health outcome categories in humans: birth, child and adult reproductive, endocrine, child neurodevelopment, nutritional, circulatory, respiratory, skin-related and cancers. Bisphenol A (BPA) is associated with decreased anoclitoral distance in infants, type 2 diabetes (T2D) in adults, insulin resistance in children and adults, polycystic ovary syndrome, obesity and hypertension in children and adults and cardiovascular disease (CVD); other bisphenols have not been evaluated. Phthalates, the only plasticisers identified, are associated with spontaneous pregnancy loss, decreased anogenital distance in boys, insulin resistance in children and adults, with additional associations between certain phthalates and decreased birth weight, T2D in adults, precocious puberty in girls, reduced sperm quality, endometriosis, adverse cognitive development and intelligence quotient (IQ) loss, adverse fine motor and psychomotor development and elevated blood pressure in children and asthma in children and adults. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) but not other flame retardants, and some PFAS were identified and are all associated with decreased birth weight. In general populations, PCBs are associated with T2D in adults and endometriosis, bronchitis in infants, CVD, non-Hodgkin's lymphoma (NHL) and breast cancer. In PCB-poisoned populations, exposure is associated with overall mortality, mortality from hepatic disease (men), CVD (men and women) and several cancers. PBDEs are adversely associated with children's cognitive development and IQ loss. PBDEs and certain PFAS are associated with changes in thyroid function. PFAS exposure is associated with increased body mass index (BMI) and overweight in children, attention deficit hyperactive disorder (ADHD) in girls and allergic rhinitis. Potential protective associations were found, namely abnormal pubertal timing in boys being less common with higher phthalate exposure, increased high-density lipoprotein (HDL) with exposure to mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and reduced incidence of chronic lymphocytic lymphoma (a subtype of NHL) with PCB exposure. Conclusions: Exposure to plastic-associated chemicals is associated with adverse outcomes across a wide range of human health domains, and every plastic-associated chemical group is associated with at least one adverse health outcome. Large gaps remain for many plastic-associated chemicals. Recommendations: For research, we recommend that efforts are harmonised globally to pool resources and extend beyond the chemicals included in this umbrella review. Priorities for primary research, with ensuing systematic reviews, could include micro- and nanoplastics as well as emerging plastic-associated chemicals of concern such as bisphenol analogues and replacement plasticisers and flame retardants. With respect to chemical regulation, we propose that safety for plastic-associated chemicals in humans cannot be assumed at market entry. We therefore recommend that improved independent, systematic hazard testing for all plastic-associated chemicals is undertaken before market release of products. In addition because of the limitations of laboratory-based testing for predicting harm from plastic in humans, independent and systematic post-market bio-monitoring and epidemiological studies are essential to detect potential unforeseen harms.

Evaluating Phthalates and Bisphenol in Foods: Risks for Precocious Puberty and Early-Onset Obesity

Recent scientific results indicate that diet is the primary source of exposure to endocrine-disrupting chemicals (EDCs) due to their use in food processing, pesticides, fertilizers, and migration from packaging to food, particularly in plastic or canned foods. Although EDCs are not listed on nutrition labels, their migration from packaging to food could inadvertently lead to food contamination, affecting individuals by inhalation, ingestion, and direct contact. The aim of our narrative review is to investigate the role of phthalates and bisphenol A (BPA) in foods, assessing their risks for precocious puberty (PP) and early-onset obesity, which are two clinical entities that are often associated and that share common pathogenetic mechanisms. The diverse outcomes observed across different studies highlight the complexity of phthalates and BPA effects on the human body, both in terms of early puberty, particularly in girls, and obesity with its metabolic disruptions. Moreover, obesity, which is independently linked to early puberty, might confound the relationship between exposure to these EDCs and pubertal timing. Given the potential public health implications, it is crucial to adopt a precautionary approach, minimizing exposure to these EDCs, especially in vulnerable populations such as children.

Exploring the relationships between exposure levels of bisphenols and phthalates and prostate cancer occurrence

We established an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneously analyzing the metabolites of bisphenols and phthalates in urine to identify the associations between these exposure levels and prostate cancer (PCa) based on a case-control study. After purifying urine samples with SPE, 18 metabolites were separated on a C18 column, and MS detection was performed. The UPLC-MS/MS method has been proven effective at evaluating bisphenol and phthalate exposure (0.020-0.20 μg/L of the limits of detection, 71.8 %∼119.4 % of recoveries, 0.4 %∼8.2 % of precision). Logistic regression explored the association between exposure level and PCa in 187 PCa cases and 151 controls. The detection rates of bisphenol A (BPA) and most phthalate metabolites were 100 % ranging from 0.06-46.74 and 0.12-899.92 μg/g creatinine, respectively, while the detection rates of other bisphenols and mono-benzyl phthalate (MBzP) are low, ranging from 0 % to 21.85 %. Correlation analysis of the metabolite levels indicated that the exposure sources of BPA, di-ethyl phthalate (DEP), and di(2-ethylhexyl) phthalate (DEHP) were different, and that the exposure sources of di-n-butyl phthalate (DnBP) and di-isobutyl phthalate (DiBP) may differ between two groups. Logistic regression analysis revealed that BPA (OR<0.45 vs ≥1.43 =10.02) and DEHP exposure (OR<21.75 vs ≥45.42 =48.26) increased the risk of PCa.

Exploring noninvasive matrices for assessing long-term exposure to phthalates: a scoping review

The phthalic acid esters (PAEs) are one class of the most abundant and frequently studied pseudo-persistent organic pollutants. Noninvasive urine is an effective substrate for evaluating PAE exposure, but repeated sampling is needed to overcome this bias. This adds much work to on-site collection and the cost of detection increases exponentially. Therefore, the aim of this study was to conduct a scope review to describe the detection methods and validity of the use of other noninvasive matrices, such as nails and hair, for assessing long-term exposure to PAEs. The PubMed, Web of Science and China National Knowledge Infrastructure (CNKI), electronic databases were searched from 1 January 2000 to 3 April 2024, and 12 studies were included. Nine and three studies used hair and nails, respectively, as noninvasive matrices for detecting PAE exposure. Five articles compared the results of nail or hair and urine tests for validity of the assessment of PAE exposure. The preprocessing and detection methods for these noninvasive samples are also described. The results of this review suggest that, compared with nails, hair may be more suitable as a noninvasive alternative matrix for assessing long-term exposure to PAEs. However, sample handling procedures such as the extraction and purification of compounds from hair are not uniform in various studies; therefore, further exploration and optimization of this process, and additional research evidence to evaluate its effectiveness, are needed to provide a scientific basis for the promotion and application of hair detection methods for assessing long-term PAE exposure levels.

Hazard identification of endocrine-disrupting carcinogens (EDCs) in relation to cancers in humans

Endocrine disrupting chemicals or carcinogens have been known for decades for their endocrine signal disruption. Endocrine disrupting chemicals are a serious concern and they have been included in the top priority toxicants and persistent organic pollutants. Therefore, researchers have been working for a long time to understand their mechanisms of interaction in different human organs. Several reports are available about the carcinogen potential of these chemicals. The presented review is an endeavor to understand the hazard identification associated with endocrine disrupting carcinogens in relation to the human body. The paper discusses the major endocrine disrupting carcinogens and their potency for carcinogenesis. It discusses human exposure, route of entry, carcinogenicity and mechanisms. In addition, the paper discusses the research gaps and bottlenecks associated with the research. Moreover, it discusses the limitations associated with the analytical techniques for detection of endocrine disrupting carcinogens.

Phthalate exposure and markers of biological aging: The mediating role of inflammation and moderating role of dietary nutrient intake

Limited evidence has suggested a relationship between phthalate exposure and biological aging. This study investigated the association between phthalate exposure and biological aging, focusing on the mediating role of inflammation and the interaction with dietary nutrient intake. Data were analyzed from a nationwide cross-sectional survey comprising 12,994 participants aged 18 and above. Eight phthalate metabolites were detected in spot urine samples. Biological aging was assessed using the Klemera-Doubal method-biological age (KDM-BA) acceleration, phenotypic age (PA) acceleration, and homeostatic dysregulation (HD). The systemic immune-inflammation index (SII) evaluated systemic inflammation. The individual and combined associations between phthalate exposure and biological aging were assessed using linear regression, weighted quantile sum (WQS) regression, and quantile g-computation (qgcomp). The participants had a mean age of 47 years, with 50.7 % male and 44.8 % non-Hispanic white. Most phthalate metabolites were positively correlated with KDM-BA acceleration (β = 0.306-0.584), PA acceleration (β = 0.081-0.281), and HD (β = 0.016-0.026). Subgroup analysis indicated that men, older individuals, and non-Hispanic whites are particularly sensitive populations. WQS regression and qgcomp analyses consistently indicated a positive association between mixed phthalate exposure and HD, highlighting MEHHP as the most significant contributing metabolite. Mediation analyses showed inflammation partially mediated the association between phthalate metabolites and biological aging. Significant interactions regarding biological aging were found between specific phthalate metabolites and dietary nutrients (carotenoids, vitamins A, B1, B2, B6, B12, niacin, and selenium) intake. These findings indicated that the association between phthalate exposure and biological aging was mediated by inflammation, with nutrient intake mitigating this effect.

Advances in immunology of male reproductive toxicity induced by common environmental pollutants

Humans are exposed to an ever-increasing number of environmental toxicants, some of which have gradually been identified as major risk factors for male reproductive health, even associated with male infertility. Male infertility is usually due to the reproductive system damage, which may be influenced by the exposure to contaminants such as heavy metals, plasticizers, along with genetics and lifestyle. Testicular immune microenvironment (TIM) is important in maintaining normal physiological functions of the testis, whether disturbed TIM after exposure to environmental toxicants could induce reproductive toxicity remains to be explored. Therefore, the current review aims to contribute to the further understanding of exposure and male infertility by characterizing environmental exposures and the effect on TIM. We first summarized the male reproductive toxicity phenotypes induced by common environmental pollutants. Contaminants including heavy metals and plastic additives and fine particulate matter (PM2.5), have been repetitively associated with male infertility, whereas emerging contaminants such as perfluoroalkyl substances and micro(nano)plastics have also been found to disrupt TIM and lead to male reproductive toxicity. We further reviewed the importance of TIM and its homeostasis in maintaining the normal physiological functions of the testis. Most importantly, we discussed the advances in immunology of male reproductive toxicity induced by metals and metalloids, plastic additives, persistent organic pollutants (POPs), micro(nano)plastic and PM2.5 to suggest the importance of reproductive immunotoxicology in the future study of environmental toxicants, but also contribute to the development of effective prevention and treatment strategies for mitigating adverse effects of environmental pollutants on human health.

Association between environmental phthalates exposure and gut microbiota and metabolome in dementia with Lewy bodies

BACKGROUND

Emerging evidence has shown the potential involvement of phthalates (PAEs) exposure in the development of dementia with Lewy bodies (DLB). Metabolomics can reflect endogenous metabolites variation in the progress of disease after chemicals exposure. However, little is known about the association between PAEs, gut microbiota and metabolome in DLB.

OBJECTIVE

We aim to explore the intricate relationship among urinary PAEs metabolites (mPAEs), dysbiosis of gut bacteria, and metabolite profiles in DLB.

METHODS

A total of 43 DLB patients and 45 normal subjects were included in this study. Liquid chromatography was used to analyze the levels of mPAEs in the urine of the two populations. High-throughput sequencing and liquid chromatography-mass spectrometry were used to analyze gut microbiota and the profile of gut metabolome, respectively. The fecal microbiota transplantation (FMT) experiment was performed to verify the potential role of mPAEs on gut dysbiosis contribute to aggravating cognitive dysfunction in α-synuclein tg DLB/PD mice.

RESULTS

The DLB patients had higher DEHP metabolites (MEOHP, MEHHP and MEHP), MMP and MnBP, lower MBP and MBzP than the control group and different microbiota. A significantly higher abundance of Ruminococcus gnavus and lower Prevotella copri, Prevotella stercorea and Bifidobacterium were observed in DLB. Higher 3 DEHP metabolites, MMP, MnBP and lower MBP and MBzP were significantly negatively associated with Prevotella copri, Prevotella stercorea and Bifidobacterium. Additionally, using metabolomics, we found that altered bile acids, short-chain fatty acids and amino acids metabolism are linked to these mPAEs. We further found that FMT of fecal microbiota from highest DEHP metabolites donors significantly impaired cognitive function in the germ-free DLB/PD mice.

CONCLUSION

Our study suggested that PAEs exposure may alter the microbiota-gut-brain axis and providing novel insights into the interactions among environmental perturbations and microbiome-host in pathogenesis of DLB.

Macrophage polarization as a novel endpoint for assessing combined risk of phthalate esters

Combined exposure to phthalate esters (PAEs) has garnered increasing attention due to potential synergistic effects on human health. This study aimed to develop an in vitro model using human macrophages to evaluate the combined toxicity of PAEs and explore the underlying mechanisms. A high-throughput screening system was engineered by expressing a PPRE-eGFP reporter in THP-1 monocytes to monitor macrophage polarization upon PAEs exposure. Individual PAEs exhibited varied inhibitory effects on M2 macrophage polarization, with mono(2-ethylhexyl) phthalate (MEHP) being the most potent. Isobologram analysis revealed additive interactions when MEHP was combined with other PAEs, resulting in more pronounced suppression of M2 markers compared to individual compounds. Mechanistic studies suggested PAEs may exert effects by modulating PPARγ activity to inhibit M2 polarization. Notably, an equimolar mixture of six PAEs showed additive inhibition of M2 markers. In vivo experiments corroborated the combined hepatotoxic effects, with mice exposed to a PAEs mixture exhibiting reduced liver weight, dyslipidemia, and decreased hepatic M2 macrophages compared to DEHP alone. Transcriptome analysis highlighted disruptions in PPAR signaling, and distinct pathway alterations on cholesterol metabolism in the mixture group. Collectively, these findings underscore the importance of evaluating mixture effects and provide a novel approach for hazard assessment of combined PAEs exposure with implications for environmental health risk assessment.