Endocrine disrupting chemicals and obesity prevention: scoping review.

INTRODUCTION: Exposure to endocrine disrupting chemicals (EDCs) can result in alterations of natural hormones in the body. The aim of this review article is to highlight the knowledge about EDCs and obesity. METHODS: A scoping review of the electronic literature was performed using PubMed platform for studies on EDCs and obesity published between the years 2013-2023. A total of 10 systematic reviews and meta-analysis studies met our inclusion criteria on more prominent EDCs focusing mainly on bisphenols, including parabens, triclosan, and phthalates, and their association with obesity. DESIGN: Scoping review. RESULTS: EDCs, mostly bisphenols and phthalates, are related to health effects, while there is less information on the impact of parabens and triclosan. A series of negative physiological effects involving obesogenic, diabetogenic, carcinogenic, and inflammatory mechanisms as well as epigenetic and microbiota modulations was related to a prolonged EDCs exposure. A more profound research of particular pollutants is required to illuminate the accelerating effects of particular EDCs, mixtures or their metabolites on the mechanism of the development of obesity. CONCLUSION: Considering the characteristics of EDCs and the heterogeneity of studies, it is necessary to design specific studies of effect tracking and, in particular, education about daily preventive exposure to EDCs for the preservation of long-term public health.

[Determination of ten bisphenols and five parabens in urine by solid supported liquid-liquid extraction and liquid chromatography-tandem mass spectrometry].

Bisphenols (BPs) and parabens (PBs) are of great concern for environmental pollution and human health because of their endocrine-disrupting effects and potential health hazards. Urinary biomonitoring of BPs and PBs can provide basic data for human internal exposure evaluation, which is a prerequisite for accurately assessing their health risks. In this study, we developed a new pretreatment procedure based on solid supported liquid-liquid extraction (SLE) for the simultaneous separation of ten BPs and five PBs in human urine, followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) analysis. In the instrumental analysis, the HPLC conditions and MS/MS parameters were comprehensively optimized. Accurate qualitative and quantitative determination of ten BPs and five PBs was achieved by introducing a ternary gradient elution system of water, methanol, and acetonitrile for LC separation. During sample pretreatment, the extraction solvent and elution volume were optimized. Specifically, urine samples were held at room temperature and centrifuged at 3000 r/min for 10 min. The supernatant (2 mL) was then transferred to a glass tube, and the pH was adjusted to 5.0 using HCl (0.5 mL; 0.1 mol/L) and NaAc-HAc buffer (1.5 mL). Thereafter, ß-glucuronidase-arylsulfatase (20 µL) and surrogate standard solutions (10 ng;13C12-BPS,13C12-BPAF,13C6-MeP, and 13C6-BuP) were added, and the mixture was incubated in a shaker bath in the dark at 37 ℃ for 16 h. After incubation, the hydrolyzed sample (4 mL) was loaded onto an SLE cartridge and equilibrated for a minimum of 5 min to ensure the solution was completely absorbed by the packing material. Subsequently, the target chemicals were eluted with a mixed ethyl acetate/n-hexane solution (3∶7, v/v; 15 mL). Separation of the targets was performed on a ZORBAX SB-C18 reversed-phase column (250 mm×4.6 mm, 5 µm) using an acetonitrile-methanol-water system as the mobile phase. The method was verified by spiking mixed urine samples at three levels (1, 5, and 50 µg/L), with the recoveries ranging from 84.3% to 119.8%. Except for bisphenols (BPS), whose matrix effect was calculated as -21.8%, the matrix effects of other analytes were lower than 20%, indicating low matrix interference. The linear ranges of the analytes varied from 0.1-500 µg/L to 1-500 µg/L, with correlation coefficients higher than 0.995. The method limits of quantification for target chemicals ranged from 0.03 to 0.30 µg/L, and the relative standard deviations of intra- and inter-day experiments were 1.4%-8.4% and 5.7%-14.6%, respectively, suggesting high stability and reproducibility. The method was successfully applied to the determination of ten BPs and five PBs in 10 urine samples from a general population. The concentrations of target chemicals in the human urine samples varied. Methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and bisphenol A (BPA) were detected in all samples, with median mass concentrations of 1.10, 0.60, 0.21, and 0.55 µg/L, respectively. The detection rates of the other chemicals were less than 50%, which may be related to the production and use of specific chemicals, their bioavailability, and biological metabolism in humans.

Deciphering trends in replacing preservatives in cosmetics intended for infants and sensitive population.

The present study aims to investigate the current trends in replacing conventional preservatives with multifunctional ingredients with antimicrobial properties for preservation of cosmetics for infants or sensitive population, to decrease their potential for contact dermatitis. We first reviewed the labels of cosmetics purchased from the Chinese market for conventional preservatives and multifunctional ingredients with antimicrobial properties, of which the actual contents were further quantified by chromatographic methods. We identified 7 traditional preservatives (phenoxyethanol, benzoic acid (salts), methylparaben, benzyl alcohol, sorbic acid (salts), propylparaben, and methylisothiazolinone), and 11 alternative ingredients with antimicrobial activities (ethylhexylglycerin, butylene glycol, caprylyl glycol, propylene glycol, 1,2-hexanediol, p-anisic acid, hydroxyacetophenone, pentylene glycol, decylene glycol, caprylhydroxamic acid, and aminomethyl propanol) in descending order of prevalence. The contents of all identified preservatives and ingredients were either below regulatory limits or in the range that is generally regarded to be safe. Further challenge with microorganisms indicated irrespective of the composition of preservation systems, product preservation could be compromised under test conditions. We conclude that multifunctional ingredients with antimicrobial properties in cosmetics have the potential to completely replace or significantly reduce the use of traditional preservatives while retaining comparative preservative efficacy. Future attentions may need to be shifted to the safety of those multifunctional ingredients with antimicrobial properties.

Radiolytic degradation of 4-hydroxybenzoate in aerated and deoxygenated aqueous solutions.

The radiolytic degradation of 4-hydroxybenzoate (4-HBA-) in aerated, oxygen-free and N2O-saturated aqueous solutions at concentrations of 0.10 and 0.25 mmol/dm3 were gamma irradiated at different doses in a source of Co-60. The results show that ·OH adds predominantly to the 3 position of the aromatic ring, and elimination of the acid group leads to the degradation of 4-HBA-. With an N2O-saturated 0.10 mmol/dm3 4-HBA- solution, total degradation occurred at 1.6 kGy, and with a 0.25 mmol/dm3 solution, total degradation occurred at 3.5 kGy. In the aerated and oxygen-free 0.25 mmol/dm3 4-HBA- solutions, the behavior was similar, degradation occurring at a dose of 13.1 kGy. At the concentration of 0.10 mmol/dm3, total degradation occurred at 7.0 kGy, with small amounts of radiolytic products and byproducts. We propose a mechanism for the degradation of 4-HBA- caused by water radicals produced in the three environments, leading to formation of the identified stable products. Oxidation was followed by chemical oxygen demand (COD), which decreased as the 4-HBA- concentration increased. The kinetics showed a pseudo-first-order behavior. The rate constant of degradation was similar for the solutions with and without oxygen.

[Rapid determination of nine preservatives in tobacco flavor by three phase-hollow fiber-liquid phase microextraction-high performance liquid chromatography].

Tobacco flavors are extensively utilized in traditional tobacco products, electronic nicotine, heated tobacco products, and snuff. To inhibit fungal growth arising from high moisture content, preservatives such as benzoic acid (BA), sorbic acid (SA), and parabens are often incorporated into tobacco flavors. Nonetheless, consuming preservatives beyond safety thresholds may pose health risks. Therefore, analytical determination of these preservatives is crucial for both quality assurance and consumer protection. For example, BA and SA can induce adverse reactions in susceptible individuals, including asthma, urticaria, metabolic acidosis, and convulsions. Parabens, because of their endocrine activity, are classified as endocrine-disrupting chemicals. Despite extensive research, the concurrent quantification of trace-level hydrophilic (BA and SA) and hydrophobic (methylparaben, ethylparaben, isopropylparaben, propylparaben, butylparaben, isobutylparaben, and benzylparaben) preservatives in tobacco flavors remains challenging. Traditional liquid phase extraction coupled with high performance liquid chromatography (HPLC) often results in high false positive rates and inadequate sensitivity. In contrast, tandem mass spectrometry offers high sensitivity and specificity; however, its widespread application is limited by laborious sample preparation and significant operational costs. Therefore, it is crucial to establish a fast and sensitive sample pretreatment and analysis method for the nine preservatives in tobacco flavors. In this study, a method for the simultaneous determination of the nine preservatives (SA, BA and seven parabens) in tobacco flavor was established based on three phase-hollow fiber-liquid phase microextraction (3P-HF-LPME) technology combined with HPLC. To obtain the optimal pretreatment conditions, extraction solvent type, sample phase pH, acceptor phase pH, sample phase volume, extraction time, and mass fraction of sodium chloride, were examined. Additionally, the HPLC parameters, including UV detection wavelength and mobile phase composition, were refined. The optimal extraction conditions were as follows: dihexyl ether was used as extraction solvent, 15 mL sample solution (pH 4) was used as sample phase, sodium hydroxide aqueous solution (pH 12) was used as acceptor phase, and the extraction was carried out at 800 r/min for 30 min. Chromatographic separation was accomplished using an Agilent Poroshell 120 EC-C18 column (100 mm×3 mm, 2.7 µm) and a mobile phase comprising methanol, 0.02 mol/L ammonium acetate aqueous solution (containing 0.5% acetic acid), and acetonitrile for gradient elution. Under the optimized conditions, the nine target analytes showed good linear relationships in their respective linear ranges, the correlation coefficients (r) were ≥0.9967, limits of detection (LODs) and quantification (LOQs) were 0.02-0.07 mg/kg and 0.08-0.24 mg/kg, respectively. Under two spiked levels, the enrichment factors (EFs) and extraction recoveries (ERs) of the nine target analytes were 30.6-91.1 and 6.1%-18.2%, respectively. The recoveries of the nine target analytes ranged from 82.2% to 115.7% and the relative standard deviations (RSDs) (n=5) were less than 14.5% at low, medium and high levels. The developed method is straightforward, precise, sensitive, and well-suited for the rapid screening of preservatives in tobacco flavor samples.

The impact of methylparaben and chlorine on the architecture of Stenotrophomonas maltophilia biofilms.

The biofilm architecture is significantly influenced by external environmental conditions. Biofilms grown on drinking water distribution systems (DWDS) are exposed to environmental contaminants, including parabens, and disinfection strategies, such as chlorine. Although changes in biofilm density and culturability from chemical exposure are widely reported, little is known about the effects of parabens and chlorine on biofilm morphology and architecture. This is the first study evaluating architectural changes in Stenotrophomonas maltophilia colony biofilms (representatives of bacterial communities presented in DWDS) induced by the exposure to methylparaben (MP) at environmental (15 µg/L) and in-use (15 mg/L) concentrations, and chlorine at 5 mg/L, using widefield epi-fluorescence mesoscopy with Mesolens. The GFP fluorescence of colony biofilms allowed the visualization of internal structures and Nile Red fluorescence permitted the inspection of the distribution of lipids. Our data show that exposure to MP triggers physiological and morphological adaptation in mature colony biofilms by increasing the complexity of internal structures, which may confer protection to embedded cells from external chemical molecules. These architectural modifications include changes in lipid distribution as an adaptive response to MP exposure. Although chlorine exposure affected colony biofilm diameter and architecture, the colony roundness was completely affected by the simultaneous presence of MP and chlorine. This work is pioneer in using Mesolens to highlight the risks of exposure to emerging environmental contaminants (MP), by affecting the architecture of biofilms formed by drinking water (DW) bacteria, even when combined with routine disinfection strategies.

Urinary biomarkers of environmental exposures and asthma morbidity in a school inner city asthma study.

BACKGROUND: The burden of pediatric asthma and other allergic diseases is not evenly distributed among United States populations. OBJECTIVE: To determine whether urinary biomarkers are associated with asthma morbidity, and if associations vary by child race, ethnicity and sex. METHODS: This study includes n = 152 children with physician-diagnosed asthma who participated in the School Inner-City Asthma Intervention Study (SICAS-2). Metabolites of phenol, paraben, polycyclic aromatic hydrocarbons, and phthalate analytes were analyzed from urine samples collected at baseline. Asthma symptom days over the past 2 weeks were dichotomized to no asthma symptom days or any asthma symptom days. Cross-sectional regression models were adjusted for age, sex, number of colds, household income, prescription control, race and ethnicity, body mass index (BMI) percentile, and smoke exposure. Weighted quantile sum regression was used to analyze each chemical class and a total mixture effect, controlling for the same covariates. Analyses were conducted with the assistance of the National Institute of Environmental Health Sciences Children's Health Exposure Analysis Resource (CHEAR). RESULTS: Participants were mostly Hispanic/Latino and low income with an average age of 7.83 years and the average maximum asthma symptom days over the past two weeks of 2.13 (standard deviation: 3.56). The maximum concentrations indicate extreme values for several chemicals, including bisphenol-3, 2,5-dichlorophenol, propyl and methyl parabens, triclosan, methyl paraben and cotinine. We found a significant interaction effect and differing contributions of analytes for children with allergen sensitivity versus those that did not. For stratified analyses assessing effect modification by child race and ethnicity, weighted quantile sum interaction models showed reduced odds of asthma symptoms to a greater magnitude in children of other races and ethnicities compared to Black, Non-Hispanic children. CONCLUSIONS: Preliminary analyses of the association between environmental chemical exposure and asthma symptoms among inner-city children revealed an inverse association, which may be due to personal care and medication use and can be understood further in future analyses. Beneficial effects were detected for most of the chemicals.

Breaking barriers in pharmaceutical analysis: Streamlined UV spectrometric quantification and stability profiling of haloperidol and methylparaben in liquid formulations.

This study aims to quantify haloperidol and methylparaben in a liquid pharmaceutical formulation (2 mg/ml) using UV spectrometry and the simultaneous equations method. Additionally, we explored the stability of haloperidol under various stress conditions. The UV analysis revealed maximum absorption peaks at 248 nm for haloperidol and 256 nm for methylparaben, using a 1 % (v/v) lactic acid solution as the solvent. Method validation, conducted according to ICH guidelines, affirmed the method's reliability, showing excellent results in terms of linearity, precision, accuracy, and sensitivity. The method allows direct application to finished products, enabling simultaneous quantification without extractions. Its simplicity, speed, and cost-effectiveness make it ideal for routine controls in pharmaceutical industry haloperidol solution analyses. The method extends to monitoring forced degradation, indicating photolytic and hydrolytic degradation under acidic and basic conditions, while affirming thermal and oxidative stability. This proposed UV spectrometric method serves as a compelling alternative to pharmacopeia-recommended techniques, simplifying simultaneous determination of the active ingredient and preservative. This streamlines analysis, reducing time and costs. Additionally, it proves valuable in small industries lacking sophisticated instrumentation, offering insights into active ingredient behavior during forced degradation.

Solar-driven environmental fate of chlorinated parabens in natural and engineered water systems.

Parabens are classified as emerging contaminants in global waters, and the ubiquitous emergence of their high-risk chlorinated products generated from chlorine-based wastewater disinfection has attracted increasing attention. However, rather limited information is available on their photofate after discharging into surface waters, and their degradation behavior after solar-based engineering water treatment is unclear. Herein, the reactivity of four chlorinated parabens with different photochemically produced reactive intermediates was measured. Quantitative contribution analysis in abating such compounds showed the dominance of direct photolysis in sunlit natural freshwaters. Introducing a technical solar/peroxymonosulfate (PMS) system could greatly improve the removal of chlorinated parabens. The economic analysis suggested that chlorinated parabens exhibited a minimum value of economic input as 93.41-158.04 kWh m-3 order-1 at 0.543-0.950 mM PMS. The high-resolution mass spectrometry analysis of the degradation products suggested that dechlorination, hydroxylation, and ester chain cleavage were the dominant transformation pathways during photolysis and solar/PMS treatment. Furthermore, the in silico prediction indicated severe aquatic toxicity of certain products but enhanced biodegradability. Overall, this investigation filled a knowledge gap on the reactivity of chlorinated parabens with diverse reactive transients and their quantitative contributions to the photolysis and solar/PMS treatment of emerging micropollutants in water.

Exposure to biocides and their potential exposure sources among adults: A nationwide population-based study in South Korea.

Biocides are present in personal care (including preservatives or antibacterials), pest control, and disinfectant products (including non-agricultural insecticides, fungicides, and disinfectants), and their long-term exposure may induce adverse health effects in humans. Therefore, in this study, we assessed the exposure levels and major exposure predictors of biocides among nationally representative Korean adults. The target group included adults (≥19 years) participating in the Korean National Environmental Health Survey (KoNEHS) 2015-2020. We employed survey-weighted multiple regression analysis and conditional inference trees analysis to assess the associations between demographic characteristics, behavioral sources (including personal care product use, pesticide use, and dietary patterns), and urinary levels of phenol (triclosan [TCS]), parabens (methyl paraben [MP], ethyl paraben [EP], propyl paraben [PP], and butyl paraben [BP]), and the pyrethroid insecticide metabolite (3-phenoxybenzoic acid [3-PBA]). Urinary EP, BP, and 3-PBA levels were higher in South Korean adults compared with those in Western countries. Major exposure predictors for MP, EP, and PP included the use of personal care products such as sunscreen, makeup, and hair care products in KoNEHS 2018-2020. Major exposure predictors for TCS and BP were vegetable consumption, and those for 3-PBA were mosquitocide use during summer in KoNEHS 2018-2020. However, these predictors were not observed in KoNEHS 2015-2017. Collectively, our findings suggest that biocide exposure predictors vary according to changes in product use and diet habits of individuals. Therefore, developing strategies to mitigate biocide exposure based on the demographic and behavioral characteristics of the general population is imperative.

Substrate specificity modification of paraben hydrolase and tannase from Aspergillus oryzae.

Paraben hydrolase and tannase catalyze the hydrolysis of parabens (4-hydroxybenzoic acid esters) and gallic acid (3,4,5-trihydroxybenzoic acid) esters, respectively. Paraben hydrolase (AoPrbA) and tannase (AoTanB) from Aspergillus oryzae belong to the tannase family in the ESTHER database. However, the substrate specificities of AoPrbA and AoTanB are narrow. Based on structural information of Aspergillus niger tannase (PDB code 7k4o), we constructed five single variants of AoPrbA (Thr200Glu, Phe231Gln, Leu232Gln, Ile361Tyr, and Leu428Ser) and four of AoTanB (Glu203Asp, Glu203Thr, His237Ala, and Ser440Leu) to investigate substrate discrimination between AoPrbA and AoTanB. Each variant was expressed in Pichia pastoris and were purified from the culture supernatant. Five purified variants of AoPrbA and four variants of AoTanB showed reduced paraben hydrolase and tannase activities compared with AoPrbA and AoTanB wild types, respectively. Interestingly, the AoPrbA wild type did not hydrolyze gallic acid methyl ester, whereas the Thr200Glu, Leu232Gln, and Leu428Ser variants did, indicating that these three variants acquired tannase activity. In particular, the Leu428Ser variant exhibited considerably greater hydrolysis of gallic acid and protocatechuic acid methyl esters. Meanwhile, the AoTanB wild type, and Glu203Asp, His237Ala and Ser440Leu variants hydrolyzed the protocatechuate methyl and 4-hydroxybenzoate ethyl esters; however, the Glu203Thr variant did not hydrolyze above-mentioned substrates. Additionally, the ratio of paraben hydrolase activity to tannase activity in Ser440Leu was markedly elevated.

Association of Phenols, Parabens, and Their Mixture with Maternal Blood Pressure Measurements in the PROTECT Cohort.

BACKGROUND: Phenols and parabens are two classes of high production volume chemicals that are used widely in consumer and personal care products and have been associated with reproductive harm and pregnancy complications, such as preeclampsia and gestational diabetes. However, studies examining their influence on maternal blood pressure and gestational hypertension are limited. OBJECTIVES: We investigated associations between individual phenols, parabens, and their mixture on maternal blood pressure measurements, including systolic and diastolic blood pressure (SBP and DBP) and hypertension during pregnancy (defined as stage 1 or 2 hypertension), among N=1,433 Puerto Rico PROTECT study participants. METHODS: We examined these relationships cross-sectionally at two time points during pregnancy (16-20 and 24-28 wks gestation) and longitudinally using linear mixed models (LMMs). Finally, we used quantile g-computation to examine the mixture effect on continuous (SBP, DBP) and binary (hypertension during pregnancy) blood pressure outcomes. RESULTS: We observed a trend of higher odds of hypertension during pregnancy with exposure to multiple analytes and the overall mixture [including bisphenol A (BPA), bisphenol S (BPS), triclocarbon (TCC), triclosan (TCS), benzophenone-3 (BP-3), 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), methyl paraben (M-PB), propyl paraben (P-PB), butyl paraben (B-PB), and ethyl paraben (E-PB)], especially at 24-28 wk gestation, with an adjusted mixture odds ratio(OR)=1.57 (95% CI: 1.03, 2.38). Lower SBP and higher DBP were also associated with individual analytes, with results from LMMs most consistent for methyl paraben (M-PB) or propyl paraben (P-PB) and increased DBP across pregnancy [adjusted M-PB ß=0.78 (95% CI: 0.17, 1.38) and adjusted P-PB ß=0.85 (95% CI: 0.19, 1.51)] and for BPA, which was associated with decreased SBP (adjusted ß=-0.57; 95% CI: -1.09, -0.05). Consistent with other literature, we also found evidence of effect modification by fetal sex, with a strong inverse association observed between the overall exposure mixture and SBP at visit 1 among participants carrying female fetuses only. CONCLUSIONS: Our findings indicate that phenol and paraben exposure may collectively increase the risk of stage 1 or 2 hypertension during pregnancy, which has important implications for fetal and maternal health. https://doi.org/10.1289/EHP14008.

Complete genome sequence of the 4-hydroxybenzoate-degrading bacterium Gymnodinialimonas sp. 57CJ19, a potential novel species from intertidal sediments.

A bacterium Gymnodinialimonas sp. 57CJ19, was isolated from the intertidal sediments of Aoshan Bay, and further assays showed that it has the ability to degrade the antibacterial preservative 4-hydroxybenzoate. The complete genome sequence was sequenced, and phylogenomic analyses indicated that strain 57CJ19 represents a potential novel species in the genus Gymnodinialimonas (family Rhodobacteraceae). Its genome contains a 3,861,607-bp circular chromosome with 61.25% G + C content. Gene prediction revealed 3716 protein-encoding genes, 41 tRNA genes, 3 rrn operons, and 3 non-coding RNA genes. Functional annotation revealed a complete metabolic pathway for 4-hydroxybenzoate. The genome sequence of strain 57CJ19 provides new insights into the potential and underlying genomic basis of aromatic compound pollutant degradation by marine bacteria.

Inhibitory effects of parabens on human and rat 17ß-hydroxysteroid dehydrogenase 1: Mechanisms of action and impact on hormone synthesis.

Parabens are commonly used preservatives in cosmetics, food, and pharmaceutical products. The objective of this study was to examine the effect of nine parabens on human and rat 17ß-hydroxysteroid dehydrogenase 1 (17ß-HSD1) in human placental and rat ovarian cytosols, as well as on estradiol synthesis in BeWo cells. The results showed that the IC50 values for these compounds varied from methylparaben with the weakest inhibition (106.42 µM) to hexylparaben with the strongest inhibition (2.05 µM) on human 17ß-HSD1. Mode action analysis revealed that these compounds acted as mixed inhibitors. For rats, the IC50 values ranged from the weakest inhibition for methylparaben (no inhibition at 100 µM) to the most potent inhibition for hexylparaben (0.87 µM), and they functioned as mixed inhibitors. Docking analysis indicated that parabens bind to the region bridging the NADPH and steroid binding sites of human 17ß-HSD1 and the NADPH binding site of rat 17ß-HSD1. Bivariate correlation analysis demonstrated negative correlations between LogP, molecular weight, heavy atoms, and apolar desolvation energy, and the IC50 values of these compounds. In conclusion, this study identified the inhibitory effects of parabens and their binding mechanisms on human and rat 17ß-HSD1, as well as their impact on hormone synthesis.

Toxicity of the emerging pollutants propylparaben and dichloropropylparaben to terrestrial plants.

Propylparaben (PrP) and dichloropropylparaben (diClPrP) are found in soil worldwide, mainly due to the incorporation of urban sludge in crop soils and the use of non-raw wastewater for irrigation. Studies on the adverse effects of PrP on plants are incipient and not found for diClPrP. PrP and diClPrP were evaluated at concentrations 4, 40, and 400 µg/L for their phytotoxic potential to seeds of Allium cepa (onion), Cucumis sativus (cucumber), Lycopersicum sculentum (tomato), and Lactuca sativa (lettuce), and cytotoxic, genotoxic potential, and for generating oxygen-reactive substances in root meristems of A. cepa bulbs. PrP and diClPrP caused a significant reduction in seed root elongation in all four species. In A. cepa bulb roots, PrP and diClPrP resulted in a high prophase index; in addition, PrP at 400 µg/L and diClPrP at the three concentrations significantly decreased cell proliferation and caused alterations in a significant number of cells. Furthermore, diClPrP concentrations induced the development of hooked roots in onion bulbs. The two chemical compounds caused significant changes in the modulation of catalase, ascorbate peroxidase, and guaiacol peroxidase, disarming the root meristems against hydroxyl radicals and superoxides. Therefore, PrP and diClPrP were phytotoxic and cytogenotoxic to the species tested, proving dangerous to plants.

Urinary paraben exposure increases the risk of a low estimated glomerular filtration rate in Taiwanese general population.

BACKGROUND: The inconsistent relationship between chemical exposure and estimated glomerular filtration rate (eGFR) has been examined in only a few studies. We investigated the association between paraben exposure and indicators of renal function in a total of 361 individuals recruiting from a representative study. METHOD: The levels of urinary parabens, including methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP), were measured using UPLC-MS/MS. The association between paraben exposure and indices of renal function was assessed using multiple logistic regression and Bayesian Kernel Machine Regression (BKMR). RESULTS: The median levels of urinary parabens in the adult group were significantly higher than those in the minor group, that is, 397 vs. 148 ng/mL for MeP, 38.8 vs. 13.6 ng/mL for EtP, 117 vs. 57.7 ng/mL for PrP, and 6.61 vs. 2.79 ng/mL for BuP (all P < 0.001). In the adult group, multivariate regression models confirmed a positive association between the albumin-to-creatinine ratio and urinary MeP (ß = 0.580) and a positive association of BUN (ß = 0.061) and a negative association of eGFR (ß = -0.051) with urinary EtP (all P < 0.001). In the adult group, compared with the lowest tertile group, the adjusted odds ratio in the third tertile (T3) of urinary EtP levels indicated a 3.08 times increased risk of eGFR abnormalities, followed by the second tertile (T2) with a 2.63 times increased risk. The generalized additive model (GAM) and BKMR models showed a non-linear correlation between urinary EtP levels and early CKD, as well as reduced eGFR. We observed a significant positive cumulative effect of urinary paraben on eGFR, and a significant positive single exposure effect of urinary EtP with eGFR abnormality. CONCLUSION: We found a significant association between exposure to EtP and an increased risk of high BUN levels and decreased eGFR.

Propylparaben exposure impairs G2/M and metaphase-anaphase transition during mouse oocyte maturation.

Propylparaben (PrPB) is a known endocrine disrupting chemicals that is widely applied as preservative in pharmaceuticals, food and cosmetics. PrPB has been detected in human urine samples and human serum and has been proven to cause functional decline in reproduction. However, the direct effects of PrPB on mammalian oocyte are still unknown. Here, we demonstrationed that exposure to PrPB disturbed mouse oocyte maturation in vitro, causing meiotic resumption arrest and first polar body extrusion failure. Our results indicated that 600 µM PrPB reduced the rate of oocyte germinal vesicle breakdown (GVBD). Further research revealed that PrPB caused mitochondrial dysfunction and oxidative stress, which led to oocyte DNA damage. This damage further disturbed the activity of the maturation promoting factor (MPF) complex Cyclin B1/ Cyclin-dependent kinase 1 (CDK1) and induced G2/M arrest. Subsequent experiments revealed that PrPB exposure can lead to spindle morphology disorder and chromosome misalignment due to unstable microtubules. In addition, PrPB adversely affected the attachment between microtubules and kinetochore, resulting in persistent activation of BUB3 amd BubR1, which are two spindle-assembly checkpoint (SAC) protein. Taken together, our studies indicated that PrPB damaged mouse oocyte maturation via disrupting MPF related G2/M transition and SAC depended metaphase-anaphase transition.

Co-exposure of parabens, benzophenones, triclosan, and triclocarban in human urine from children and adults in South China.

Endocrine-disrupting chemicals (EDCs) are pervasive in the environment, prompting significant public concern regarding human exposure to these pollutants. In this study, we analyzed the levels of various endocrine-disrupting compounds, including parabens (PBs), benzophenones (BzPs), triclocarban (TCC) and triclosan (TCS), across 565 urine samples collected from residents of South China. All 11 target chemicals were detected at relatively high frequencies (41-100%), with the most prevalent ones being 3,4-dihydroxybenzoic acid (5.39 ng/mL), methyl-paraben (5.12 ng/mL), ethyl-paraben (3.11 ng/mL) and triclosan (0.978 ng/mL). PBs emerged as the most predominant group with a median concentration of 32.2 ng/mL, followed by TCs (sum of TCC and TCS, 0.998 ng/mL) and BzPs (0.211 ng/mL). Notably, urinary concentrations of PBs in adults were significantly higher (p < 0.01) compared to children, while BzPs and TCs were elevated in children (p < 0.001). The increased presence of BzPs and TCs in children is a cause for concern, given their heightened sensitivity and vulnerability to chemicals. Significant correlations were found between urinary target compounds and demographic factors, including gender, age and body mass index. Specifically, females, younger adults (18 ≤ age ≤ 35) and individuals with under/normal weight (16 ≤ BMI ≤ 23.9) were found to have higher exposure levels to EDCs, as indicated by the median values of their estimated daily intakes. Despite these higher levels still being lower than the acceptable daily intake thresholds, the health risks stemming from simultaneous exposure to these EDCs must not be overlooked.

Occurrence and Environmental Risk Assessment of Contaminants of Emerging Concern in Brazilian Surface Waters.

We investigated the occurrence and the environmental risk of eight contaminants of emerging concern (CECs; acetaminophen, naproxen, diclofenac, methylparaben, 17ß-estradiol, sulfathiazole, sulfadimethoxine, and sulfamethazine) in three Brazilian water bodies, namely, the Monjolinho River Basin (São Paulo State), the Mogi Guaçu River (São Paulo State), and the Itapecuru River (Maranhão State) in three sampling campaigns. The CECs were only quantified in surface water samples collected at the Monjolinho River Basin. Acetaminophen, naproxen, and methylparaben were detected in the range of <200 to 575.9 ng L-1, <200 to 224.7 ng L-1, and <200 to 303.6 ng L-1, respectively. The detection frequencies of the three measured compounds were between 33% and 67%. The highest concentrations of CECs were associated with intense urbanization and untreated sewage discharge. Furthermore, CEC concentrations were significantly correlated with total organic carbon, electrical conductivity, and dissolved oxygen levels, suggesting that domestic pollution from urban areas is an important source in the distribution of CECs in the Monjolinho River Basin. The environmental risk assessment indicated a high risk for acetaminophen (risk quotient [RQ] values between 2.1 and 5.8), a medium risk for naproxen (RQs between 0.6 and 0.7), and a low risk for methylparaben (RQs < 0.1) to the freshwater biota of the Monjolinho River Basin. Our findings show potential threats of CECs in Brazilian water bodies, especially in vulnerable areas, and reinforce the need for improvements in environmental regulations to include monitoring and control of these compounds in aquatic systems. Environ Toxicol Chem 2024;43:2199-2210. © 2024 SETAC.

Sex-Specific and Trimester-Specific Associations of Prenatal Exposure to Bisphenols, Parabens, and Triclosan with Neonatal Birth Size and Gestational Age.

Bisphenols, parabens, and triclosan (TCS) are common endocrine disrupters used in various consumer products. These chemicals have been shown to cross the placental barrier and affect intrauterine development of fetuses. In this study, we quantified serum levels of six bisphenols, five parabens, and TCS in 483 pregnant women from southern China. Quantile-based g-computation showed that combined exposure to bisphenols, parabens, and TCS was significantly (p < 0.05) and negatively associated with birth weight (ß = -39.9, 95% CI: -73.8, -6.1), birth length (ß = -0.19, 95% CI: -0.34, -0.04), head circumference (ß = -0.13, 95% CI: -0.24, -0.02), and thoracic circumference (ß = -0.16, 95% CI: -0.29, -0.04). An inverse correlation was also identified between mixture exposure and gestational age (ß = -0.12, 95% CI: -0.24, -0.01). Bisphenol A (BPA), bisphenol Z (BPZ), bisphenol AP (BPAP), propylparaben (PrP), and TCS served as the dominant contributors to the overall effect. In subgroup analyses, male newborns were more susceptible to mixture exposure than females, whereas the exposure-outcome link was prominent among pregnant women in the first and second trimesters. More evidence is warranted to elucidate the impacts of exposure to mixtures on birth outcomes, as well as the underlying mechanisms.