Estrogenic potency of benzophenone UV filters in breast cancer cells: proliferative and transcriptional activity substantiated by docking analysis

Estrogen receptor/androgen receptor transcriptional activation of benzophenone derivatives and integrated approaches to testing and assessment (IATA) for estrogenic effects

Estrogen receptor (ER) and androgen receptor (AR) transactivation assays for the benzophenone compounds (BPs) were performed using hERα-HeLa-9903 cells for ER and MMTV/22Rv1_GR-KO cells for AR. Results showed that some BPs, such as BP-1, BP-2, 4OH-BP, 4DHB, and 4-MBP, showed agonistic activity on ER with a higher RPCmax than 1 nM 17-β estradiol. The other BPs (BP, BP-3, BP-6, BP-7, and BP-8) showed low RPCmax in accordance with the OECD Test guideline (TG) 455 criteria, with BP-4 as the only ER-negative. However, the potency of the BPs was at least 1000 times less than the reference chemical, 17-β-estradiol. None of the BPs exhibited agonistic activity on AR except BP-2 which showed a small increase in activity. For further evaluation of the estrogenic effect of BPs based on the integrated approaches to testing and assessment (IATA) approach, existing data on ER binding, steroidogenesis, MCF-7 cell proliferation, and in vivo uterotrophic assays were collected and evaluated. There seemed to be a close association between the in vitro data on BPs, especially ER transcriptional activity, and the in vivo results of increased uterine weight. This case study implied that integrated approaches using in vitro data can be a useful tool for the prediction of in vivo data for estrogenic effects, without the need for additional animal toxicity tests.

Multi-omics reveals the molecular mechanism of the combined toxic effects of PFOA and 4-HBP exposure in MCF-7 cells and the key player: mTORC1

With the discovery of evidence that many endocrine-disrupting chemicals (EDCs) in the environment influence human health, their toxic effects and mechanisms have become a hot topic of research. However, investigations into their endocrine-disrupting toxicity under combined binary exposure, especially the molecular mechanism of combined effects, have rarely been documented. In this study, two typical EDCs, perfluorooctanoic acid (PFOA) and 4-hydroxybenzophenone (4-HBP), were selected to examine their combined effects and molecular mechanism on MCF-7 cell proliferation at environmentally relevant exposure concentrations. We have successfully established a model to evaluate the binary combined toxic effects of endocrine disruptors, presenting combined effects in a simple and direct way. Results indicated that the combined effect changed from additive to synergistic from 1.25 × 10-8 M to 4 × 10-7 M. Metabolomics analyses suggested that exposure to PFOA and 4-HBP caused significant alterations in purine metabolism, arginine, and proline metabolism and had superimposed influences on metabolism. Enhanced combined effects were observed in glycine, serine, and threonine metabolic pathways compared to exposure to PFOS and 4-HBP alone. Additionally, the differentially expressed genes (DEGs) are primarily involved in Biological Processes, especially protein targeting the endoplasmic reticulum, and significantly impact the oxidative phosphorylation and thermogenesis-related KEGG pathway. By integrating metabolome and transcriptome analyses, PFOA and 4-HBP regulate purine metabolism, the TCA cycle, and endoplasmic reticulum protein synthesis in MCF-7 cells via mTORC1, which provides genetic material, protein, and energy for cell proliferation. Furthermore, molecular docking confirmed the ability of PFOA and 4-HBP to stably bind the estrogen receptor, indicating that they have different binding pockets. Collectively, these findings will offer new insights into understanding the mechanisms by which EDCs produce combined toxicity.

A review of sources, pathways, and toxic effects of human exposure to benzophenone ultraviolet light filters

Benzophenone ultraviolet light filters (BPs) are high-production-volume chemicals extensively used in personal care products, leading to widespread human exposure. Given their estrogenic properties, the potential health risks associated with exposure to BPs have become a public health concern. This review aims to summarize sources and pathways of exposure to BPs and associated health risks. Dermal exposure, primarily through the use of sunscreens, constitutes a major pathway for BP exposure. At a recommended application rate, dermal exposure of BP-3 via the application of sunscreens may reach or exceed the suggested reference dose. Other exposure pathways to BPs, such as drinking water, seafood, and packaged foods, contribute minimal to the overall dose. Inhalation is a minor pathway of exposure; however, its contribution cannot be ignored. Human exposure to BPs is an order of magnitude higher in North America than in Asia and Europe. Studies conducted on laboratory animals and cells have consistently demonstrated the toxic effects of BP exposure. BPs are estrogenic and elicit reproductive and developmental toxicities. Furthermore, neurotoxicity, hepatotoxicity, nephrotoxicity, and carcinogenicity have been reported from chronic BP exposure. In addition to animal and cell studies, epidemiological investigations have identified associations between BPs and couples' fecundity and other reproductive disorders, as well as adverse birth outcomes. Further studies are urgently needed to understand the risks posed by BPs on human health.

Benzophenone induces cardiac developmental toxicity in zebrafish embryos by upregulating Wnt signaling

Benzophenone (BP) is found in many popular consumer products, such as cosmetics. BP potential toxicity to humans and aquatic organisms has emerged as an increased concern. In current study, we utilized a zebrafish model to assess BP-induced developmental cardiotoxicity. Following BP exposure, zebrafish embryos exhibited developmental toxicity, including increased mortality, reduced hatchability, delayed yolk sac absorption, and shortened body length. Besides, BP exposure induced cardiac defects in zebrafish embryos, comprising pericardial edema, reduced myocardial contractility and rhythm disturbances, and altered expression levels of cardiac developmental marker genes. Mechanistically, BP exposure disturbed the redox state and increased the level of apoptosis in zebrafish cardiomyocytes. Transcriptional expression levels of Wnt signaling genes, involving lef1, axin2, and β-catenin, were upregulated after BP treatment. Inhibition of Wnt signaling with IWR-1 could rescue the BP-induced cardiotoxicity in zebrafish. In summary, BP exposure causes cardiotoxicity via upregulation of the Wnt signaling pathway in zebrafish embryos.

Benzophenone-3 exposure alters composition of tumor infiltrating immune cells and increases lung seeding of 4T1 breast cancer cells

Environmental chemicals are a persistent and pervasive part of everyday life. A subset of environmental chemicals are xenoestrogens, compounds that bind to the estrogen receptor (ER) and drive estrogen-related processes. One such chemical, benzophenone-3 (BP3), is a common chemical in sunscreen. It is a potent UV protectant but also is quickly absorbed through the skin. While it has been approved by the FDA, there is a renewed interest in the safety of BP3, particularly in relation to breast cancer. The focus of this study was to examine the impact that BP3 has on triple negative breast cancer (TNBC) through alterations to cells in the immune microenvironment. In this study, we exposed female mice to one of two doses of BP3 before injecting them with a TNBC cell line. Several immune endpoints were examined both in the primary tissues and from in vitro studies of T cell behavior. Our studies revealed that in the lung tumor microenvironment, exposure to BP3 not only increased the number of metastases, but also the total area of tumor coverage. We also found that BP3 caused alterations in immune populations in a tissue-dependent manner, particularly in T cells. Taken together, our data suggest that while BP3 may not directly affect the proliferation of TNBC, growth and metastasis of TNBC-derived tumors can be altered by BP3 exposures via the alterations in the immune populations of the tumor microenvironment.

Cell cycle, apoptosis, cell differentiation, and lipid metabolism gene expression in endometriotic tissue and exposure to parabens and benzophenones

AIM

To describe the expression profile in endometriotic tissue of genes involved in four signaling pathways related to the development and progression of endometriosis (cell cycle, apoptosis, cell differentiation and lipid metabolism) and to explore its relationship with the women exposure to chemicals with hormonal activity released from cosmetics and personal care products (PCPs).

METHODS

This cross-sectional study, encompassed within the EndEA study, comprised a subsample of 33 women with endometriosis. Expression levels of 13 genes (BMI1, CCNB1, CDK1, BAX, BCL2L1, FOXO3, SPP1, HOXA10, PDGFRA, SOX2, APOE, PLCG1 and PLCG2) in endometriotic tissue and urinary concentrations of 4 paraben (PB) and 3 benzophenone (BP) congeners were quantified. Bivariate linear and logistic regression analyses were performed to explore the associations between exposure and gene expression levels.

RESULTS

A total of 8 out 13 genes (61.5 %) were expressed in >75 % of the samples. Exposure to congeners of PBs and/or BPs was associated with the overexpression of CDK1 gene (whose protein drives cells through G2 phase and mitosis), HOXA10 and PDGFRA genes (whose proteins favor pluripotent cell differentiation to endometrial cells), and APOE (whose protein regulates the transport and metabolism of cholesterol, triglycerides and phospholipids in multiple tissues) and PLCG2 genes (whose protein creates 1D-myo-inositol 1,4,5-trisphosphate and diacylglycerol, two important second messengers).

CONCLUSIONS

Our findings suggest that women exposure to cosmetic and PCP-released chemicals might be associated with the promotion of cell cycle and cell differentiation as well as with lipid metabolism disruption in endometriotic tissue, three crucial signaling pathways in the development and progression of endometriosis. However, further studies should be accomplished to confirm these preliminary data.

Maternal exposure to benzophenone derivatives and their impacts on offspring's birth outcomes in a Middle Eastern population

Widespread use of benzophenones (BPs), a group of environmental phenolic compounds, is suspected of interfering with human health. The association of prenatal exposure to benzophenone derivatives with birth outcomes including birth weight and length, head, arm and thoracic circumference, abnormalities, corpulence index and anterior fontanelle diameter (AFD) was investigated. Mother-infant pairs of 166 within PERSIAN cohort population in Isfahan, Iran, in the 1st and 3rd trimesters of pregnancy were assessed. Four common benzophenone metabolites including 2,4-dihydroxy benzophenone (BP-1), 2-hydroxy-4-methoxy benzophenone (BP-3), 4-hydroxy benzophenone (4-OH-BP) and 2,2'-dihydroxy-4-methoxy benzophenone (BP-8) were measured in maternal urine samples. The median concentration of 4-OH-BP, BP-3, BP-1 and BP-8 were 3.15, 16.98, 9.95 and 1.04 µg/g Cr, respectively. In the 1st trimester, 4-OH-BP showed a significant correlation with AFD in total infants, decreasing 0.034 cm AFD per a log unit increase of 4-OH-BP. Within the male neonates, 4-OH-BP in the 1st and BP-8 in the 3rd trimester were significantly associated with head circumference and AFD increase, respectively. Among female neonates in the 3rd trimester, increasing 4-OH-BP and BP-3 concentration was correlated with a decrease in birth weight and AFD, respectively. This study demonstrated that all the target BP derivatives can influence normal fetal growth at any age of the pregnancy, nevertheless, to support these findings further studies are needed in a large and different group population.

Benzophenone-3: Comprehensive review of the toxicological and human evidence with meta-analysis of human biomonitoring studies

BACKGROUND

Benzophenone-3 (BP-3) and its major metabolite benzophenone-1 (BP-1) are widely used as UV filters in sunscreens and cosmetics to prevent sunburn and skin damage, or as stabilizers to prevent photodegradation in many commercial products. As a result, their presence is ubiquitous in the environment, wildlife and humans. Based on endocrine disruption concerns, international regulatory agencies are performing a closer evaluation.

OBJECTIVE AND METHODS

This work aimed to comprehensively review the available human relevant evidence for safety issues in MEDLINE/PubMed in order to create a structured database of studies, as well as to conduct an integrative analysis as part of the Human Biomonitoring for Europe (HBM4EU) Initiative.

RESULTS

A total of 1,635 titles and abstracts were screened and 254 references were evaluated and tabulated in detail, and classified in different categories: i) exposure sources and predictors; ii) human biomonitoring (HBM) exposure levels to perform a meta-analysis; iii) toxicokinetic data in both experimental animals and humans; iv) in vitro and in vivo rodent toxicity studies; and v) human data on effect biomarkers and health outcomes. Our integrative analysis showed that internal peak BP-3 concentrations achieved after a single whole-body application of a commercially available sunscreen (4% w/w) may overlap with concentrations eliciting endocrine disrupting effects in vitro, and with internal concentrations causing in vivo adverse female reproductive effects in rodents that were supported by still limited human data. The adverse effects in rodents included prolonged estrous cycle, altered uterine estrogen receptor gene expression, endometrium hyperplasia and altered proliferation and histology of the mammary gland, while human data indicated menstrual cycle hormonal alterations and increased risk of uterine fibroids and endometriosis. Among the modes of action reported (estrogenic, anti-androgenic, thyroid, etc.), BP-3 and especially BP-1 showed estrogenic activity at human-relevant concentrations, in agreement with the observed alterations in female reproductive endpoints. The meta-analysis of HBM studies identified a higher concern for North Americans, showing urinary BP-3 concentrations on average 10 and 20 times higher than European and Asian populations, respectively.

DISCUSSION AND CONCLUSIONS

Our work supports that these benzophenones present endocrine disrupting properties, endorsing recent European regulatory efforts to limit human exposure. The reproducible and comprehensive database generated may constitute a point of departure in future risk assessments to support regulatory initiatives. Meanwhile, individuals should not refrain from sunscreen use. Commercially available formulations using inorganic UV filters that are practically not absorbed into systemic circulation may be recommended to susceptible populations.

Occurrence and profile characteristics of environmental phenols in human urine from a rural area in Northwestern China

Many environmental phenols, such as bisphenols, benzophenones and parabens, are known as endocrine disruptors and can adversely affect human health. However, the knowledge of human exposure to common environmental phenols in Chinese rural areas is insufficient. In this context, 181 urine samples were collected from participants in a rural area in Northwest China and were analyzed for nine bisphenols, three benzophenones and four parabens. Bisphenol A (BPA), bisphenol S, benzophenone-1 (BP-1), benzophenone-3 (BP-3), 4-hydroxybenzophenone, methylparaben (MeP), ethylparaben and propylparaben (PrP) were detected in more than 50% of the urine samples, with median concentrations of 0.938 ng/mL, 0.0111 ng/mL, 0.191 ng/mL, 1.30 ng/mL, 0.0320 ng/mL, 25.9 ng/mL, 4.31 ng/mL and 1.94 ng/mL, respectively. A significant positive correlation was observed between BP-1 and BP-3, as well as between MeP and PrP, indicating metabolic transformation and combined use, respectively. The concentrations of MeP and PrP in females were significantly higher than those in males, suggesting that females were exposed to more MeP and PrP than males. Urinary concentrations of BPA, BP-3, MeP and PrP could be influenced by age. Other demographic information, such as annual household income, education and occupation was not associated with the exposure level of the targeted phenols in adults. The estimated daily intakes of the analytes except BPA were all below their respective tolerable/acceptable daily intake levels. This study profiles the demographic differences in the exposure to environmental phenols in general populations from rural areas and provides information on risk assessments.

Interaction mechanism of benzophenone-type UV filters on bovine serum albumin: Insights from structure-affinity relationship

Benzophenone (BP)-type UV filters can cause structural changes of carrier protein in plasma. The binding process of five BP-type UV filters with bovine serum albumin (BSA) was investigated by multiple characterization methods, along with their structure-affinity relationship involving the structure of the five BP-type UV filters and their binding affinity for BSA. The BP-type UV filters investigated bound to BSA spontaneously, and altered conformation of BSA. The binding constants and number of binding sites between BP-type UV filters and BSA were 10³-10⁶ M^-1 and 0.82-1.26, respectively. These BP-type UV filters and BSA interacted with the same binding forces and went through the similar binding process, suggesting that the benzophenone skeleton structure was primarily responsible for the BP-type UV filters and BSA binding, and changes in the structure of the BSA. The BP-type UV filters with hydroxyl substituent (BP-1 and BP-9) and non-polar molecules (BP-6) had a high affinity for binding BSA and had a greater impact on BSA conformation.

Prenatal exposure to mixtures of phthalates and phenols and body mass index and blood pressure in Spanish preadolescents

BACKGROUND

Pregnant women are simultaneously exposed to several non-persistent endocrine-disrupting chemicals, which may influence the risk of childhood obesity and cardiovascular diseases later in life. Previous prospective studies have mostly examined single-chemical effects, with inconsistent findings. We assessed the association between prenatal exposure to phthalates and phenols, individually and as a mixture, and body mass index (BMI) and blood pressure (BP) in preadolescents.

METHODS

We used data from the Spanish INMA birth cohort study (n = 1,015), where the 1st and 3rd- trimester maternal urinary concentrations of eight phthalate metabolites and six phenols were quantified. At 11 years of age, we calculated BMI z-scores and measured systolic and diastolic BP. We estimated individual chemical effects with linear mixed models and joint effects of the chemical mixture with hierarchical Bayesian kernel machine regression (BKMR). Analyses were stratified by sex and by puberty status.

RESULTS

In single-exposure models, benzophenone-3 (BP3) was nonmonotonically associated with higher BMI z-score (e.g. Quartile (Q) 3: β = 0.23 [95% CI = 0.03, 0.44] vs Q1) and higher diastolic BP (Q2: β = 1.27 [0.00, 2.53] mmHg vs Q1). Methyl paraben (MEPA) was associated with lower systolic BP (Q4: β = -1.67 [-3.31, -0.04] mmHg vs Q1). No consistent associations were observed for the other compounds. Results from the BKMR confirmed the single-exposure results and showed similar patterns of associations, with BP3 having the highest importance in the mixture models, especially among preadolescents who reached puberty status. No overall mixture effect was found, except for a tendency of higher BMI z-score and lower systolic BP in girls.

CONCLUSIONS

Prenatal exposure to UV-filter BP3 may be associated with higher BMI and diastolic BP during preadolescence, but there is little evidence for an overall phthalate and phenol mixture effect.

The Association between Sex Hormones, Pubertal Milestones and Benzophenone-3 Exposure, Measured by Urinary Biomarker or Questionnaire

Experimental studies have suggested benzophenone-3 (BP-3), a sunscreen ingredient, may have endocrine-disrupting properties. A cohort of girls were recruited at ages 6-7 years and returned semi-annually for pubertal maturation staging, provided blood for serum hormone analyses [estradiol, estrone, testosterone, dehydroepiandrosterone-sulfate (DHEA-S)], and urine to measure BP-3 concentrations. We found a significant negative linear association between amount of reported sunscreen use and testosterone levels at the onset of puberty (N = 157, adjusted β = -0.0163, 97.5% CI:-0.0300,-0.0026). The 2nd quartile of the BP-3 biomarker had earlier thelarche compared to the 1st quartile (N = 282, adjusted HR = 1.584, 97.5% CI:1.038,2.415). Results suggest that higher report of sunscreen use may be associated with lower testosterone levels at thelarche and a non-linear relationship between the BP-3 urinary biomarker and onset of puberty, although the clinical significance of the finding is limited and may be a random effect. Improved methods of BP-3 exposure characterization are needed.

Assessment of human exposure to benzophenone-type UV filters: A review

To avoid the harmful effects of UV radiation, benzophenone-type UV filters (BPs) are widely used in personal care products and other synthetic products. Biomonitoring studies have shown the presence of BPs in various human biological samples, raising health concerns. However, there is a paucity of data on the global human exposure to this group of contaminants. In this study, we compiled data on the body burden of BPs along with the possible exposure routes and biotransformation pathways. BPs can easily penetrate the skin barrier and thus, they can be absorbed through the skin. In the human body, BPs can undergo Phase I (mainly demethylation and hydroxylation) and Phase II (mainly glucuronidation and sulfation) biotransformations. From a total of 158 studies, most of the studies are related to urine (concentration up to 92.7 mg L^-1), followed by those reported in blood (up to 0.9 mg L^-1) and milk (up to 0.8 mg L^-1). Among BPs, benzophenone-1 and benzophenone-3 are the most commonly detected congeners. The body burden of BPs is associated with various factors, including the country of residence, lifestyle, income, education level, and ethnicity. The presence of BPs in maternal urine (up to 1.1 mg L^-1), placenta (up to 9.8 ng g^-1), and amniotic fluid (up to 15.7 μg L^-1) suggests potential risks of prenatal exposure. In addition, transplacental transfer of BPs is possible, as demonstrated by their presence in maternal serum and cord serum. The possible association of BPs exposure and health effects was discussed. Future human biomonitoring studies and studies on the potential health effects are warranted. Overall, this review provides a summary of the global human exposure to BPs and can serve as supporting evidence to guide usage in order to protect humans from being exposed to BPs.

Effects of consumer products chemicals ingredients and their mixtures on the estrogen receptor/androgen receptor transcriptional activation

Unlike the environmental pollutants or industrial chemicals, the chemicals in consumer products may pose higher levels of risks, depending on how the chemicals are used in the products and how humans interact with the products. Recently, endocrine disrupting chemicals in cosmetics, personal care products, cleaners, sunscreens, and vinyl products were analytically quantified and many active chemicals including phthalates, parabens and bisphenols were detected. This indicates a wide range of exposures from common products. In this study, 35 chemicals known to be ingredients of consumer products were selected and screened for the transactivation of estrogen receptors and androgen receptors. From the results of individual chemicals, the activity of binary/ternary mixture prepared from the agonists for the ER transcription activity was measured, and compared to the predicted values obtained by the full logistic model. The measured and the predicted values were found to be very similar. This study may suggest that prediction of mixture activity by proper models would be one of the supportive tools for the risk assessment and sound regulation of chemical mixtures which have potential endocrine disrupting effects in consumer products.

The association of prenatal exposure to benzophenones with gestational age and offspring size at birth

In recent decades, emerging environmental pollutants such as endocrine-disrupting chemicals (EDCs) have become a particular concern. This study examined the association of maternal exposure to benzophenones as one of the EDCs with gestational age and evaluated their effects on birth outcomes including birth weight, birth length, head circumference, and Ponderal Index. We assessed 166 pregnant mothers of the PERSIAN cohort population of Isfahan, Iran, in the 1st and 3rd trimesters of pregnancy and their infants at birth. Four common benzophenones (BPs) including 2,4-dihydroxy benzophenone (BP-1), 2-hydroxy-4-methoxy benzophenone (BP-3), 4-hydroxy benzophenone (4-OH-BP), and 2,2'-dihydroxy-4-methoxy benzophenone (BP-8) were measured in maternal urine samples. The median urinary concentrations of 4-OH-BP, BP-3, BP-1, and BP-8 in the 1st trimester were 6.62, 7.5, 4.39, and 1.32 µg/g creatinine and those in the 3rd trimester were 3.15, 16.98, 9.95, and 1.04 µg/g creatinine, respectively. BP-3 was the predominant metabolite in both trimesters. There was a significant correlation between BP-3, BP-1, and 4-OH-BP levels (p < 0.05) but not BP-8. BP-1 showed a significant positive association with gestational age (GA) in all infants in the 1st trimester, but a negative association was observed between BP-3 and BP-1 levels and GA in girls. Classification of infants' birth weight for different GAs represented that the majority of them were appropriate for GA. However, boys' weights were heavier than girls. Also, birth outcomes of preterm (< 37 weeks) infants were noticeably lower than term infants (37-42 weeks). This study demonstrated that benzophenone derivatives especially BP-3 can affect the duration of pregnancy and consequently fetal growth in the early and late stages of pregnancy. This is more pronounced in girls; however, more investigations in a different population are needed to prove the results. Therefore, the application of these compounds as a UV protector requires precise regulation to reduce exposure, especially in pregnant women.

Type 2 Diabetes Mellitus Mediation by the Disruptive Activity of Environmental Toxicants on Sex Hormone Receptors: In Silico Evaluation

This study investigates the disruptive activity of environmental toxicants on sex hormone receptors mediating type 2 diabetes mellitus (T2DM). Toxicokinetics, gene target prediction, molecular docking, molecular dynamics, and gene network analysis were applied in silico techniques. From the results, permethrin, perfluorooctanoic acid, dichlorodiphenyltrichloroethane, O-phenylphenol, bisphenol A, and diethylstilbestrol were the active toxic compounds that could modulate androgen (AR) and estrogen-α and -β receptors (ER) to induce T2DM. Early growth response 1 (EGR1), estrogen receptor 1 (ESR1), and tumour protein 63 (TP63) were the major transcription factors, while mitogen-activated protein kinases (MAPK) and cyclin-dependent kinases (CDK) were the major kinases upregulated by these toxicants via interactions with intermediary proteins such as PTEN, AKT1, NfKβ1, SMAD3 and others in the gene network analysis to mediate T2DM. These toxicants pose a major challenge to public health; hence, monitoring their manufacture, use, and disposal should be enforced. This would ensure reduced interaction between people and these toxic chemicals, thereby reducing the incidence and prevalence of T2DM.

Determination of ultraviolet filters in human nails using an acid sample digestion followed by ultra-high performance liquid chromatography-mass spectrometry analysis

Ultraviolet filters (UV-filters) are specific chemicals that absorb and reflect UVA and UVB radiation from the sun. They are regularly used in sunscreens and in other personal care products (PCPs), and in products like plastics, adhesives, toys, or furniture finishes. This work develops and validates a new method to determine concentrations of UV-filters (BP-1, BP-2, BP-3, BP-6, BP-8, 4-OH-BP, THB, AVB) in human nail samples. Nails are easily available and are considered to be suitable indicators of cumulative and continued exposure to harmful chemicals. The treatment of nail samples includes microwave assisted digestion/extraction (MAE) in a methanolic solution of o-phosphoric acid (0.05 mol L^-1) followed by analyte determination using ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) in multiple reaction monitoring mode. The analytes were separated in less than 10 min. The digestion procedure was optimized using multivariate techniques. Matrix-matched calibration with a pig hoof matrix was used for validating the method. A study of accuracy with spiked blank samples was also conducted. The calculated detection limits varied between 0.2 and 1.5 ng g^-1, and quantification limits between 1.0 and 5.0 ng g^-1. The trueness of the method was an estimation of the recovery, which was between 90.2% and 112.2%; with an estimated precision (relative standard deviation, % RSD) lower than 12.3% for all UV-filters. Nail samples were obtained from 22 volunteers (male and female). The results showed that BP-1 and BP-3 mainly bioaccumulate in human nails.

Cosmetic and personal care product use, urinary levels of parabens and benzophenones, and risk of endometriosis: results from the EndEA study

AIM

To explore the relationship of urinary concentrations of different congeners of benzophenones and parabens with the utilization of cosmetics and personal care products (PCPs) and their impact on the risk of endometriosis, and to evaluate the influence of oxidative stress on associations found.

METHODS

This case-control study comprised a subsample of 124 women (35 cases; 89 controls). Endometriosis was confirmed (cases) or ruled out (controls) by laparoscopy, with visual inspection of the pelvis and biopsy of suspected lesions (histological diagnosis). Urinary concentrations of benzophenone-1 (BP-1), benzophenone-3 (BP-3), 4-hydroxibenzophenone (4-OH-BP), methyl- (MeP), ethyl- (EtP), propyl- (PrP), and butyl-paraben (BuP), and biomarkers of oxidative stress [lipid peroxidation (TBARS) and total antioxidant power (TAP)] were quantified. Information was gathered on the frequency of use of cosmetics and PCPs. Associations between the frequency of cosmetics/PCP use, urinary concentrations of benzophenones and parabens, oxidative stress, and endometriosis risk were explored in logistic and linear multivariable regression analyses.

RESULTS

The frequency of utilization of certain cosmetics and PCPs was significantly associated with urinary concentrations of benzophenones and parabens. After adjustment for potential confounders, the risk of endometriosis was increased in women in the second versus first terciles of MeP (OR = 5.63; p-value<0.001), BP-1 (OR = 5.12; p-value = 0.011), BP-3 (OR = 4.98; p-value = 0.008), and ƩBPs (OR = 3.34; p-value = 0.032). A close-to-significant relationship was observed between TBARS concentrations and increased endometriosis risk (OR = 1.60, p-value = 0.070) and an inverse association between TAP concentrations and this risk (OR = 0.15; p-value = 0.048). Oxidative stress results did not modify associations observed between benzophenone/paraben exposure and endometriosis risk.

CONCLUSIONS

Our findings indicate that the frequency of cosmetics and PCP utilization is a strong predictor of exposure to certain benzophenone and paraben congeners. These compounds may increase the risk of endometriosis in an oxidative stress-independent manner. Further studies are warranted to corroborate these findings.

Enhanced Disrupting Effect of Benzophenone-1 Chlorination Byproducts to the Androgen Receptor: Cell-Based Assays and Gaussian Accelerated Molecular Dynamics Simulations

Benzophenone-1 (BP-1), one of the commonly used ultraviolet filters, has caused increasing public concern due to frequently detected residues in environmental and recreational waters. Its susceptibility to residual chlorine and the potential to subsequently trigger endocrine disruption remain unknown. We herein investigated the chlorination of BP-1 in swimming pool water and evaluated the endocrine disruption toward the human androgen receptor (AR). The structures of monochlorinated (P1) and dichlorinated (P2) products were separated and characterized by mass spectrometry and ¹H-¹H NMR correlation spectroscopy. P1 and P2 exhibited significantly higher antiandrogenic activity in yeast two-hybrid assays (EC₅₀, 6.13 μM and 9.30 μM) than did BP-1 (12.89 μM). Our 350 ns Gaussian accelerated molecular dynamics simulations showed the protein dynamics in a long-time scale equilibrium, and further energy calculations revealed that although increased hydrophobic interactions are primarily responsible for enhanced binding affinities between chlorinated products and the AR ligand binding domain, the second chloride in P2 still hinders the complex motion because of the solvation penalty. The mixture of BP-1-P1-P2 elicited additive antiandrogenic activity, well fitted by the concentration addition model. P1 and P2 at 1 μM consequently downregulated the mRNA expression of AR-regulated genes, NKX3.1 and KLK3, by 1.7-9.1-fold in androgen-activated LNCaP cells. Because chlorination of BP-1 occurs naturally by residual chlorine in aquatic environments, our results regarding enhanced antiandrogenic activity and disturbed AR signaling provided evidence linking the use of personal care products with potential health risks.

Association of Maternal-Neonatal Steroids With Early Pregnancy Endocrine Disrupting Chemicals and Pregnancy Outcomes

CONTEXT

Steroids play an important role in fetal development and parturition. Gestational exposures to endocrine-disrupting chemicals (EDCs) affect steroidal milieu and pregnancy outcomes, raising the possibility of steroids serving as biomarkers. Most studies have not addressed the impact of EDC mixtures, which are reflective of real life scenarios.

OBJECTIVE

Assess the association of maternal and neonatal steroids with pregnancy outcomes and early pregnancy EDC levels.

DESIGN

Prospective analysis of mother-infant dyads.

SETTING

University hospital.

PARTICIPANTS

121 mother-infant dyads.

MAIN OUTCOME MEASURES

The associations of maternal and neonatal steroidal hormones from 121 dyads with pregnancy outcomes, the associations of first trimester EDCs individually and as mixtures with maternal and neonatal steroids in a subset of 56 dyads and the influence of body mass index (BMI), age, and offspring sex in modulating the EDC associations with steroids were determined.

RESULTS

Steroid-specific positive or negative associations with pregnancy measures were evident; many maternal first trimester EDCs were negatively associated with estrogens and positively with androgen/estrogen ratios; EDC-steroid associations were influenced by maternal age, pre-pregnancy BMI, and fetal sex; and EDCs individually and as mixtures showed direct and inverse fetal sex-dependent associations with maternal and neonatal steroids.

CONCLUSIONS

This proof-of-concept study indicates association of steroids with pregnancy outcomes depending on maternal age, prepregnancy BMI, and fetal sex, with the effects of EDCs differing when considered individually or as mixtures. These findings suggest that steroidal hormonal measures have potential to serve as biomarkers of impact of EDC exposures and pregnancy outcome.

Novel ruthenium(iii) complexes with hydroxybenzophenones: experimental and theoretical characterization and in vitro leishmanicidal activity comparing complexes and ligands

Six ruthenium–benzophenone complexes were synthesized in order to combine the chemistry of two interesting compound classes aiming at medicinal chemistry innovation.

Dioxybenzone triggers enhanced estrogenic effect via metabolic activation: in silico, in vitro and in vivo investigation

Dioxybenzone is widely used in cosmetics and personal care products and frequently detected in multiple environmental media and human samples. However, the current understanding of the metabolic susceptibility of dioxybenzone and the potential endocrine disruption through its metabolites in mimicking human estrogens remains largely unclear. Here we investigated the in vitro metabolism of dioxybenzone, detected the residue of metabolites in rats, and determined the estrogenic disrupting effects of these metabolites toward estrogen receptor α (ERα). In vitro metabolism revealed two major metabolites from dioxybenzone, i.e., M1 through the demethylation of methoxy moiety and M2 through hydroxylation of aromatic carbon. M1 and M2 were both rapidly detected in rat plasma upon exposure to dioxybenzone, which were then distributed into organs of rats in the order of livers > kidneys > uteri > ovaries. The 100 ns molecular dynamics simulation revealed that M1 and M2 formed hydrogen bond to residue Leu387 and Glu353, respectively, on ERα ligand binding domain, leading to a reduced binding free energy. M1 and M2 also significantly induced estrogenic effect in comparison to dioxybenzone as validated by the recombinant ERα yeast two-hybrid assay and uterotrophic assay. Overall, our study revealed the potential of metabolic activation of dioxybenzone to induce estrogenic disrupting effects, suggesting the need for incorporating metabolic evaluation into the health risk assessment of benzophenones and their structurally similar analogs.

Application of Various Molecular Modelling Methods in the Study of Estrogens and Xenoestrogens

In this review, applications of various molecular modelling methods in the study of estrogens and xenoestrogens are summarized. Selected biomolecules that are the most commonly chosen as molecular modelling objects in this field are presented. In most of the reviewed works, ligand docking using solely force field methods was performed, employing various molecular targets involved in metabolism and action of estrogens. Other molecular modelling methods such as molecular dynamics and combined quantum mechanics with molecular mechanics have also been successfully used to predict the properties of estrogens and xenoestrogens. Among published works, a great number also focused on the application of different types of quantitative structure-activity relationship (QSAR) analyses to examine estrogen's structures and activities. Although the interactions between estrogens and xenoestrogens with various proteins are the most commonly studied, other aspects such as penetration of estrogens through lipid bilayers or their ability to adsorb on different materials are also explored using theoretical calculations. Apart from molecular mechanics and statistical methods, quantum mechanics calculations are also employed in the studies of estrogens and xenoestrogens. Their applications include computation of spectroscopic properties, both vibrational and Nuclear Magnetic Resonance (NMR), and also in quantum molecular dynamics simulations and crystal structure prediction. The main aim of this review is to present the great potential and versatility of various molecular modelling methods in the studies on estrogens and xenoestrogens.

Critical parameters in surface plasmon resonance biosensor development: The interaction between estrogen receptor and estrogen response element as model

Estrogenic compounds are contaminants that may be active at low concentrations and are a major concern for environmental quality. They interact with organisms via Estrogen Receptors (ER). Some detection methods which have been developed use the ability of ER to interact with short consensus DNA sequences known as Estrogen Response Elements (ERE). Surface Plasmon Resonance (SPR) based techniques allow detection of interaction without labelled molecule use. Such optical transductors are widely used to convert the biological recognition signals into electric quantifiable signals. In this study, SPR is used to assess signal variation in the presence of estrogenic compounds. The combination of physical properties and biological recognition events (e.g. ER/ERE) permits the development of biosensors. These require several steps: activation of the surface, DNA sequence binding, ERE sequence evaluation, ER preparation, characterization of binding properties and regeneration of the surface. This article focuses on the mode of surface activation, protein-DNA binding conditions and the regeneration of ERE. After giving a summary of the literature concerning the usual conditions employed in these steps, an evaluation of some key parameters is given.

Effects of Benzophenone-3 and Propylparaben on Estrogen Receptor-Dependent R-Loops and DNA Damage in Breast Epithelial Cells and Mice

BACKGROUND

Endocrine-disrupting chemicals have been shown to have broad effects on development, but their mutagenic actions that can lead to cancer have been less clearly demonstrated. Physiological levels of estrogen have been shown to stimulate DNA damage in breast epithelial cells through mechanisms mediated by estrogen-receptor alpha (ERα). Benzophenone-3 (BP-3) and propylparaben (PP) are xenoestrogens found in the urine of >96% of U.S.

OBJECTIVES

We investigated the effect of BP-3 and PP on estrogen receptor-dependent transactivation and DNA damage at concentrations relevant to exposures in humans.

METHODS

In human breast epithelial cells, DNA damage following treatment with 17β-estradiol (E2), BP-3, and PP was determined by immunostaining with antibodies against γ-H2AX and 53BP1. Estrogenic responses were determined using luciferase reporter assays and gene expression. Formation of R-loops was determined with DNA: RNA hybrid-specific S9.6 antibody. Short-term exposure to the chemicals was also studied in ovariectomized mice. Immunostaining of mouse mammary epithelium was performed to quantify R-loops and DNA damage in vivo.

RESULTS

Concentrations of 1μM and 5μM BP-3 or PP increased DNA damage similar to that of E2 treatment in a ERα-dependent manner. However, BP-3 and PP had limited transactivation of target genes at 1μM and 5μM concentrations. BP-3 and PP exposure caused R-loop formation in a normal human breast epithelial cell line when ERα was introduced. R-loops and DNA damage were also detected in mammary epithelial cells of mice treated with BP-3 and PP.

CONCLUSIONS

Acute exposure to xenoestrogens (PP and BP-3) in mice induce DNA damage mediated by formation of ERα-dependent R-loops at concentrations 10-fold lower than those required for transactivation. Exposure to these xenoestrogens may cause deleterious estrogenic responses, such as DNA damage, in susceptible individuals. https://doi.org/10.1289/EHP5221.

Ensuring the Safety of Sunscreens, and Their Efficacy in Preventing Skin Cancers: Challenges and Controversies for Clinicians, Formulators, and Regulators

When people think about sun-protection or prevention of skin cancer, sunscreens readily come to mind. Sunscreen effectiveness is tested in vivo by the ability to prevent erythema of skin, yet testing methods vary between markets, and many sunscreens fail to achieve their claims. This article discusses the mechanism of action of sunscreens, Sun Protection Factor (SPF), safety concerns and the challenges for regulators. Many sunscreens that prevent erythema do not provide adequate protection as they contain anti-inflammatory agents; others have ingredients whose risks have not been fully evaluated. This article reviews the imperfect science behind sunscreens and points out the gaps in knowledge regarding safety, efficacy, public knowledge, and perception. Regulations vary between countries and only adds to the confusion. To truly prevent skin cancer, clinicians, formulators and regulators need to come together to research more and improve public education.

Skin safety and health prevention: an overview of chemicals in cosmetic products

INTRODUCTION

Cosmetic products contain a wide range of chemicals to which we are exposed every day. The aim of the study was to determine the presence of potential dangerous substances which can cause adverse health effects by examining product labels.

MATERIALS AND METHODS

A total of 283 products were collected from various shops in Lecce (Italy) and divided into 3 categories: rinse-off, leave-on and make-up. The label of every product was examined and a list including fragrances, preservatives and other chemicals of concern was created.

RESULTS

Fragrances were present in 52.3% of the examined products, mostly limonene (76.9%) and linalool (64.6%) but also citronellol (34.1%), geraniol (31.5%), coumarin (30%) and hexyl cinnamal (29.2%). Preservatives showed a rate of 60% and the most frequently identified were phenoxyethanol (48.7%), sodium benzoate (35.6%), potassium sorbate (22%), methylparaben (15.2%) and MI/MCI (9.9%). The other chemicals of concern were detected in 58% of products; included PEGs (62.3%), acrylate copolymer (34%), petrolatum (17.2%), polysorbates (14,8%), BHT (14.7%), ethylhextyl methoxycinnamate (13.6%), benzophenone-1 (3.7%), benzophenone-3 (4.9%), BHA (1.6%), cocamide DEA and toluene (1.2%).

CONCLUSIONS

The use of many of these substances is allowed within certain limits, due to their toxicity at higher concentrations. Other important aspects should be considered as, for instance, the possibility of long-term effects. On the other hand, other substances may induce several acute adverse side-effects, i.e. contact dermatitis and allergic reactions. For these reasons, an enhancement of the criteria used for cosmetics formulation is required since many chemicals used singularly or combined are potentially unsafe.

Evaluation by the Ames Assay of the Mutagenicity of UV Filters Using Benzophenone and Benzophenone-1

Ultraviolet absorbing chemicals (UV filters) are widely used in personal care products for protecting human skin and hair from damage by UV radiation. Although these substances are released into the environment during production and consumption processes, little is known about their genotoxicity effects. Our previous studies have shown that benzophenone-type UV filters exhibited acute toxicity on three species of aquatic organisms. Mutagenesis by benzophenone (BP) and benzophenone-1(BP-1) was tested in the present study by the Salmonella typhimurium/reverse mutation assay (Ames assay). All the positive reverse mutations occurred in the absence of the S9 liver extract system for both chemicals. From BP, positive mutation effects on the TA102 strain at doses of 0.05 μg/plate and 0.5 μg/plate were detected. From BP-1, positive mutation effects on the TA97 strain at doses of 0.05 μg/plate and 0.5 μg/plate, and on the TA100 strain at a dose of 0.5 μg/plate, were detected. A mixture of BP and BP-1 exhibited mutagenicity on the TA97 and TA100 strains. For the TA97 strain, the positive mutation results were detected at 10% and 50% of the mixture. For the TA100 strain, the results were detected when the mixture was at 5% and 10%. In the mixture at 5%, the concentrations of BP and BP-1 were 3.5 μg/plate and 14 μg/plate, respectively. In the 10% mixture, the doses of BP and BP-1 were 7 μg/plate and 28 μg/plate, respectively. In the 50% mixture, the doses of BP and BP-1 were 35 μg/plate and 140 μg/plate, respectively. The mixture test results suggested that there was antagonism in mutagenicity between BP and BP-1.

Occurrence, endocrine-related bioeffects and fate of bisphenol A chemical degradation intermediates and impurities: A review

In recent decades, increasing attention has been directed toward the effects of bisphenol A (BPA) as an environmental pollutant, primarily due to its demonstrated endocrine-disruptive effects. A growing body of evidence indicates that many BPA derivatives also exhibit endocrine activity and other adverse biological properties. A review of the published literature was performed to identify BPA degradation intermediates resulting from chemical degradation processes of BPA, as well as BPA's associated co-pollutants. Products of biological metabolism were not included in this study. Seventy-nine chemicals were identified. Of these chemicals, a subset - those containing two 6-membered aromatic rings connected by a central ring-linking carbon - was identified, and a further literature review was conducted to identify demonstrated biological effects associated with the chemicals in this subset. The objectives of this review were to assess the potential risks to human and environmental health associated with BPA derivatives, characterize our current understanding of BPA's degradation intermediates and co-pollutants, and aid in the identification of compounds of interest that have received insufficient scrutiny.

Thyroid Hormone-Disrupting Potentials of Major Benzophenones in Two Cell Lines (GH3 and FRTL-5) and Embryo-Larval Zebrafish

Benzophenones (BPs) have been widely used in personal care products (PCPs) such as UV protectants. Sex endocrine-disrupting effects have been documented for some BPs, but, significant knowledge gaps are present for their thyroid-disrupting effects. To investigate the thyroid-disrupting potential of BPs, a rat pituitary (GH3) and thyroid follicle (FRTL-5) cell line were employed on six BPs, i.e., benzophenone (BP), benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), benzophenone-4 (BP-4), and benzophenone-8 (BP-8). Subsequently, zebrafish ( Danio rerio) embryo exposure was conducted for three potent BPs that were identified based on the transcriptional changes observed in the cells. In GH3 cells, all BPs except BP-4 down-regulated the Tshβ, Trhr, and Trβ genes. In addition, some BPs significantly up-regulated the Nis and Tg genes while down-regulating the Tpo gene in FRTL-5 cells. In zebrafish embryo assay conducted for BP-1, BP-3, and BP-8, significant decreases in whole-body T4 and T3 level were observed at 6 day postfertilization (dpf). The up-regulation of the dio1 and ugt1ab genes in the fish suggests that decreased thyroid hormones are caused by changing metabolism of the hormones. Our results show that these frequently used BPs can alter thyroid hormone balances by influencing the central regulation and metabolism of the hormones.

Breast cancer: Lesser-known facets and hypotheses

Breast cancer is the most common cancer in females. The deteriorating environment, and lifestyle flaws are raising the frequency of this cancer. Existing therapies are not universally-effective, and they cause side effects, relapses, and high mortality rate. Alternative medications may be milder, but are less effective or are inadequate for a complex disease like the breast cancer. So, it requires the understanding that drugs are not the solution of this cancer, but prevention is the sustainable solution. In the past decades, an enormous quantum of insights on this disease has been obtained. A lifestyle based on the template of estrogenic compounds and, the resultant endocrine disruption, and acidosis, is elevating aromatase level, promoting the deleterious forms of estrogen, and inducing epithelial proliferation. This review provids a holistic account of breast cancer as a inflammatory endocrinopathy, and how it can be curbed by discipline, and awareness.

Safety of benzophenone to be used as flavouring

Benzophenone [FL-no: 07.032] has been evaluated as a flavouring substance, in FGE.69, by the EFSA Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food in 2008. Benzophenone was evaluated also by JECFA (2011) and by IARC (2013) based on studies that were not considered in the EFSA opinion on FGE.69. Therefore, the Commission requested the CEF Panel to carry out a review of existing literature on the safety of this flavouring substance. In the framework of the evaluation of benzophenone as a food contact material, the CEF Panel established a tolerable daily intake (TDI) of 0.03 mg/kg body weight (bw) per day (2009). In the present Opinion, the Panel considered the already existing evaluations by EFSA, JECFA, IARC and available literature data on benzophenone toxicity. Moreover, new data on the use levels of benzophenone as a flavouring substance have been provided. The Panel considers that there is no concern with respect to genotoxicity. The Panel considers the endocrine activities of benzophenone and its metabolite 4-hydroxybenzophenone as weak and not directly related to the observed toxic effects including the neoplastic effects in rodents. The Panel confirms that the conservative approach taken by EFSA (2009) to derive a TDI of 0.03 mg/kg bw for benzophenone is appropriate to cover the non-neoplastic effects in the chronic toxicity studies and the neoplastic effects induced in the rodent carcinogenicity studies. The TDI is in the same order of magnitude as the chronic dietary exposure of adults and children to benzophenone (10-20 μg/kg bw per day) for the amount of added flavouring substance. The Panel considers that the calculated TDI and exposure estimate are based on conservative assumptions. The Panel concludes that there is no safety concern for benzophenone under the current condition of use as a flavouring substance.

Emerging Estrogenic Pollutants in the Aquatic Environment and Breast Cancer

The number and amount of man-made chemicals present in the aquatic environment has increased considerably over the past 50 years. Among these contaminants, endocrine-disrupting chemicals (EDCs) represent a significant proportion. This family of compounds interferes with normal hormonal processes through multiple molecular pathways. They represent a potential risk for human and wildlife as they are suspected to be involved in the development of diseases including, but not limited to, reprotoxicity, metabolic disorders, and cancers. More precisely, several studies have suggested that the increase of breast cancers in industrialized countries is linked to exposure to EDCs, particularly estrogen-like compounds. Estrogen receptors alpha (ERα) and beta (ERβ) are the two main transducers of estrogen action and therefore important targets for these estrogen-like endocrine disrupters. More than 70% of human breast cancers are ERα-positive and estrogen-dependent, and their development and growth are not only influenced by endogenous estrogens but also likely by environmental estrogen-like endocrine disrupters. It is, therefore, of major importance to characterize the potential estrogenic activity from contaminated surface water and identify the molecules responsible for the hormonal effects. This information will help us understand how environmental contaminants can potentially impact the development of breast cancer and allow us to fix a maximal limit to the concentration of estrogen-like compounds that should be found in the environment. The aim of this review is to provide an overview of emerging estrogen-like compounds in the environment, sum up studies demonstrating their direct or indirect interactions with ERs, and link their presence to the development of breast cancer. Finally, we emphasize the use of in vitro and in vivo methods based on the zebrafish model to identify and characterize environmental estrogens.

Rapid assessment of estrogenic compounds by CXCL-test illustrated by the screening of the UV-filter derivative benzophenones

CXCL-test is a method that uses the estrogen-dependent secretion of the natural endogenous chemokine CXCL12 to evaluate the estrogenic activity of molecules. CXCL12 chemokine is involved in the estrogen dependent proliferation of breast cancer cells. Its measure is an indicator of cell proliferation and is used as an alternative test to classical proliferation test. Here we aimed to optimize this test, first to increase the number of tested molecules in a single assay and then to decrease the number of intermediate steps. The optimized CXCL-test was finally used for the evaluation of the estrogenic potency of emerging chemical pollutants: the UV filter benzophenones (BPs). The effect of BPs on CXCL12 secretion was also validated by real time quantitative RT-PCR. The optimized CXCL-test allowed a fast and direct assessment of estrogenic potency of molecules. The estrogenic activities of benzophenones were characterized and divided in two groups. The first one contains weak estrogenic compounds (BP, BP1, BP2, BP3, 234BP and 2344'BP). The second one contains medium estrogenic compounds (4BP, 44'BP, BP8, THB).

Migration of Parabens, Bisphenols, Benzophenone-Type UV Filters, Triclosan, and Triclocarban from Teethers and Its Implications for Infant Exposure

Parabens (p-hydroxybenzoic acid esters), bisphenols, benzophenone-type UV filters, triclosan, and triclocarban are used in a variety of consumer products, including baby teethers. Nevertheless, the exposure of infants to these chemicals through the use of teethers is still unknown. In this study, 59 teethers, encompassing three types, namely solid plastic, gel-filled, and water-filled (most labeled "bisphenol A-free"), were collected from the U.S. market and analyzed for 26 potential endocrine-disrupting chemicals (EDCs) from intact surfaces through migration/leaching tests performed with Milli-Q water and methanol. The total amount of the sum of six parent parabens (Σ₆ Parabens) leached from teethers ranged from 2.0 to 1990 ng, whereas that of their four transformation products (Σ₄ Parabens) ranged from 0.47 to 839 ng. The total amount of the sum of nine bisphenols (Σ₉ bisphenols) and 5 benzophenones (Σ₅ benzophenones) leached from teethers ranged from 1.93 to 213 ng and 0.59 to 297 ng, respectively. Triclosan and triclocarban were found in the extracts of teethers at approximately 10-fold less amounts than were bisphenols and benzophenones. Based on the amount leached into Milli-Q water, daily intake of these chemicals was estimated from the use of teethers by infants at 12 months of age. This is the first study to document the occurrence and migration of a wide range EDCs from intact surfaces of baby teethers.

Consensus Modeling for Prediction of Estrogenic Activity of Ingredients Commonly Used in Sunscreen Products

Sunscreen products are predominantly regulated as over-the-counter (OTC) drugs by the US FDA. The "active" ingredients function as ultraviolet filters. Once a sunscreen product is generally recognized as safe and effective (GRASE) via an OTC drug review process, new formulations using these ingredients do not require FDA review and approval, however, the majority of ingredients have never been tested to uncover any potential endocrine activity and their ability to interact with the estrogen receptor (ER) is unknown, despite the fact that this is a very extensively studied target related to endocrine activity. Consequently, we have developed an in silico model to prioritize single ingredient estrogen receptor activity for use when actual animal data are inadequate, equivocal, or absent. It relies on consensus modeling to qualitatively and quantitatively predict ER binding activity. As proof of concept, the model was applied to ingredients commonly used in sunscreen products worldwide and a few reference chemicals. Of the 32 chemicals with unknown ER binding activity that were evaluated, seven were predicted to be active estrogenic compounds. Five of the seven were confirmed by the published data. Further experimental data is needed to confirm the other two predictions.

Recent Advances on Endocrine Disrupting Effects of UV Filters

Ultraviolet (UV) filters are used widely in cosmetics, plastics, adhesives and other industrial products to protect human skin or products against direct exposure to deleterious UV radiation. With growing usage and mis-disposition of UV filters, they currently represent a new class of contaminants of emerging concern with increasingly reported adverse effects to humans and other organisms. Exposure to UV filters induce various endocrine disrupting effects, as revealed by increasing number of toxicological studies performed in recent years. It is necessary to compile a systematic review on the current research status on endocrine disrupting effects of UV filters toward different organisms. We therefore summarized the recent advances on the evaluation of the potential endocrine disruptors and the mechanism of toxicity for many kinds of UV filters such as benzophenones, camphor derivatives and cinnamate derivatives.

Toxicopathological Effects of the Sunscreen UV Filter, Oxybenzone (Benzophenone-3), on Coral Planulae and Cultured Primary Cells and Its Environmental Contamination in Hawaii and the U.S. Virgin Islands

Benzophenone-3 (BP-3; oxybenzone) is an ingredient in sunscreen lotions and personal-care products that protects against the damaging effects of ultraviolet light. Oxybenzone is an emerging contaminant of concern in marine environments—produced by swimmers and municipal, residential, and boat/ship wastewater discharges. We examined the effects of oxybenzone on the larval form (planula) of the coral Stylophora pistillata, as well as its toxicity in vitro to coral cells from this and six other coral species. Oxybenzone is a photo-toxicant; adverse effects are exacerbated in the light. Whether in darkness or light, oxybenzone transformed planulae from a motile state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of oxybenzone. Oxybenzone is a genotoxicant to corals, exhibiting a positive relationship between DNA-AP lesions and increasing oxybenzone concentrations. Oxybenzone is a skeletal endocrine disruptor; it induced ossification of the planula, encasing the entire planula in its own skeleton. The LC50 of planulae exposed to oxybenzone in the light for an 8- and 24-h exposure was 3.1 mg/L and 139 µg/L, respectively. The LC50s for oxybenzone in darkness for the same time points were 16.8 mg/L and 779 µg/L. Deformity EC20 levels (24 h) of planulae exposed to oxybenzone were 6.5 µg/L in the light and 10 µg/L in darkness. Coral cell LC50s (4 h, in the light) for 7 different coral species ranges from 8 to 340 µg/L, whereas LC20s (4 h, in the light) for the same species ranges from 0.062 to 8 µg/L. Coral reef contamination of oxybenzone in the U.S. Virgin Islands ranged from 75 µg/L to 1.4 mg/L, whereas Hawaiian sites were contaminated between 0.8 and 19.2 µg/L. Oxybenzone poses a hazard to coral reef conservation and threatens the resiliency of coral reefs to climate change.

Acute toxicity of benzophenone-type UV filters for Photobacterium phosphoreum and Daphnia magna: QSAR analysis, interspecies relationship and integrated assessment

The hazardous potential of benzophenone (BP)-type UV filters is becoming an issue of great concern due to the wide application of these compounds in many personal care products. In the present study, the toxicities of BPs to Photobacterium phosphoreum and Daphnia magna were determined. Next, density functional theory (DFT) and comparative molecular field analysis (CoMFA) descriptors were used to obtain more detailed insight into the structure - activity relationships and to preliminarily discuss the toxicity mechanism. Additionally, the sensitivities of the two organisms to BPs and the interspecies toxicity relationship were compared. Moreover, an approach for providing a global index of the environmental risk of BPs to aquatic organisms is proposed. The results demonstrated that the mechanism underlying the toxicity of BPs to P. phosphoreum is primarily related to their electronic properties, and the mechanism of toxicity to D. magna is hydrophobicity. Additionally, D. magna was more sensitive than P. phosphoreum to most of the BPs, with the exceptions of the polyhydric BPs. Moreover, comparisons with published data revealed a high interspecies correlation coefficient among the experimental toxicity values for D. magna and Dugesia japonica. Furthermore, hydrophobicity was also found to be the most important descriptor of integrated toxicity. This investigation will provide insight into the toxicity mechanisms and useful information for assessing the potential ecological risk of BP-type UV filters.

Hepatic oxidative stress biomarker responses in freshwater fish Carassius auratus exposed to four benzophenone UV filters

Benzophenone (BP) type UV filters are widely used in many personal care products to protect human from UV irradiation. Despite the estrogenic potencies to fish and the environmental occurrences of BP derivatives in aquatic systems, little information is available regarding their effects on the antioxidant defense system in fish. In this work, the oxidative stress induced in livers of Carassius auratus was assessed using four biomarkers. The integrated biomarker response (IBR) was applied to assess the overall antioxidant status in fish. Moreover, liver tissues were also studied histologically. The changes in the activities of antioxidant enzymes and glutathione levels suggested that BPs generates oxidative stress in fish. The IBR index revealed that the hepatic oxidative toxicity followed the order BP-1>BP-2>BP-4>BP-3. The histopathological analysis revealed lesions caused by BPs. This investigation provides essential information for assessing the potential ecological risk of BP-type UV filters.

Skin absorption and human exposure estimation of three widely discussed UV filters in sunscreens--In vitro study mimicking real-life consumer habits

Due to health concerns about safety, three UV-filters (Benzophenone-3, BP3, 10%; Ethylhexyl Methoxycinnamate, EHMC, 10%; Butyl Methoxydibenzoylmethane, BMDBM; 5%) were examined in vitro for absorption on full-thickness pig-ear skin, mimicking human in-use conditions. Kinetic profiles confirmed the rapid permeation of BP3; after the first hour of skin (frozen-stored) exposure to 2 mg/cm(2) (W/O sunscreen; recommended but unrealistic amount), about 0.5% of the applied dose passed into the receptor fluid. The absorption rate of filters was higher from W/O than from O/W emulsions. The fresh/frozen-stored skin permeability coefficient (0.83-0.54) for each UV filter was taken into account. Systemic Exposure Dosage of BP3, EHMC, BMDBM for humans as a consequence of (i) whole-body and (ii) face treatment with 0.5 mg/cm(2) of W/O sunscreen for 6-h skin exposure followed by washing and subsequent 18-h permeation (a realistic scenario) were estimated to be (i) 4744, 1032 and 1036 μg/kg-bw/day, and (ii) 153, 33 and 34 μg/kg-bw/day, respectively. From Margin of Safety for BP3, EHMC and BMDBM (i) 42, 485 and 192 as well as (ii) 1307; 15,151 and 5882, respectively, only the value of 42 (<100) for BP3 indicated a possible health risk. Escalation of a phobia towards all organic UV filters is undesirable.

Bisphenol A, benzophenone-type ultraviolet filters, and phthalates in relation to uterine leiomyoma

Bisphenol A, benzophenone-type UV filters, and phthalates are chemicals in high production and use including in a range of personal care products. Exposure of humans to these chemicals has been shown to affect endocrine function. Although short-lived, widespread exposure may lead to continual opportunity for these chemicals to elicit health effects in humans. The association of these chemicals with incident uterine leiomyoma, an estrogen sensitive disease, is not known. Urinary concentrations of bisphenol A (BPA), five benzophenone-type UV filters (2-hydroxy-4-methoxybenzophenone (2OH-4MeO-BP), 2,4-dihydroxybenzophenone (2,4OH-BP), 2,2׳-dihydroxybenzophenone (2,2׳OH-4MeO-BP), 2,2׳4,4׳-tetrahydroxybenzophenone (2,2׳4,4׳OH-BP), and 4-hydroxybenzophenone (4OH-BP), and 14 phthalate monoesters were quantified in 495 women who later underwent laparoscopy/laparotomy at 14 clinical sites for the diagnosis of fibroids. Significantly higher geometric mean creatinine-corrected concentrations of BPA, 2,4OH-BP, and 2OH-4MeO-BP were observed in women with than without fibroids [BPA: 2.09µg/g vs. 1.46µg/g p=0.004; 2,4OH-BP:11.10µg/g vs. 6.71µg/g p=0.01; 2OH-4MeO-BP: 11.31µg/g vs. 6.10µg/g p=0.01]. Mono-methyl phthalate levels were significantly lower in women with than without fibroids (1.78µg/g vs. 2.40µg/g). However, none of the exposures were associated with a significant odds ratio even when adjusting for relevant covariates. There was a lack of an association between select nonpersistent chemicals and the odds of a fibroid diagnosis.

Benzophenone-1 and nonylphenol stimulated MCF-7 breast cancer growth by regulating cell cycle and metastasis-related genes via an estrogen receptor α-dependent pathway

Endocrine-disrupting chemicals (EDC) are defined as environmental compounds that produce adverse health manifestations in mammals by disrupting the endocrine system. Benzophenone-1 (2,4-dihydroxybenzophenone, BP1) and nonylphenol (NP), which are discharged from numerous industrial products, are known EDC. The aim of this study was to examine the effects of BP1 and NP on proliferation and metastasis of MCF-7 human breast cancer cells expressing estrogen receptors (ER). Treatment with BP1 (10⁻⁵-10⁻⁷ M) and NP (10⁻⁶-10⁻⁷ M) promoted proliferation of MCF-7 cells similar to the positive control 17 -beta-estradiol (E2). When ICI 182,780, an ER antagonist, was co-incubated with E2, BP1, or NP, proliferation of MCF-7 cells returned to the level of a control. Addition of BP1 or NP markedly induced migration of MCF-7 cells similar to E2. To elucidate the underlying molecular mechanisms produced by these EDC, alterations in transcriptional and translational levels of proliferation and metastasis-related markers, including cyclin D1, p21, and cathepsin D, were determined. Data showed increase in expression of cyclin D1 and cathepsin D and decrease in p21 at both transcriptional and translational levels. However, BP1- or NP-induced alterations of these genes were blocked by ICI 182,780, suggesting that changes in expression of these genes may be regulated by an ERα-dependent pathway. In conclusion, BP1 and NP may accelerate growth of MCF-7 breast cancer cells by regulating cell cycle-related genes and promote cancer metastasis through amplification of cathepsin D.

The CXCL12 G801A polymorphism is associated with cancer risk: a meta-analysis

Background

CXCL12 is a small chemotactic cytokine belonging to the CXC chemokine family expressed in various organs. It contributes to the migration, invasion and angiogenesis of cancer cells. Recently, the CXCL12 G801A polymorphism was shown to be associated with an increased risk of various kinds of cancers, but the results were too inconsistent to be conclusive.

Methods

To solve the problem of inadequate statistical power and conflicting results, a meta-analysis of published case-control studies was performed, including 4,435 cancer cases and 6,898 controls. Odds ratios (ORs) and their 95% confidence intervals (CIs) were used to determine the strength of association between CXCL12 G801A polymorphism and cancer risk.

Results

A significant association between CXCL12 G801A polymorphism and cancer risk was found under all genetic models. Further, subgroup analysis stratified by ethnicity suggested a significant association between CXCL12 G801A polymorphism and cancer risk in the Asian subgroup under all genetic models. However, in the Caucasian subgroup, a significant association was only found under an additive genetic model and a dominant genetic model. The analysis stratified by cancer type found that CXCL12 G801A polymorphism may increase the risk of breast cancer, lung cancer, and “other” cancers. Based on subgroup stratified by source of controls, a significant association was observed in hospital-based studies under all genetic models.

Conclusions

The CXCL12 G801A polymorphism is associated with an increased risk of cancer based on current published data. In the future, large-scale well-designed studies with more information are needed to better estimate possible gene-gene or gene-environment interactions.

Endocrine disruption of oestrogen action and female reproductive tract cancers

Endocrine disrupting chemicals (EDC) are ubiquitous and persistent compounds that have the capacity to interfere with normal endocrine homoeostasis. The female reproductive tract is exquisitely sensitive to the action of sex steroids, and oestrogens play a key role in normal reproductive function. Malignancies of the female reproductive tract are the fourth most common cancer in women, with endometrial cancer accounting for most cases. Established risk factors for development of endometrial cancer include high BMI and exposure to oestrogens or synthetic compounds such as tamoxifen. Studies on cell and animal models have provided evidence that many EDC can bind oestrogen receptors and highlighted early life exposure as a window of risk for adverse lifelong effects on the reproductive system. The most robust evidence for a link between early life exposure to EDC and adverse reproductive health has come from studies on women who were exposed in utero to diethylstilbestrol. Demonstration that EDC can alter expression of members of the HOX gene cluster highlights one pathway that might be vulnerable to their actions. In summary, evidence for a direct link between EDC exposure and cancers of the reproductive system is currently incomplete. It will be challenging to attribute causality to any single EDC when exposure and development of malignancy may be separated by many years and influenced by lifestyle factors such as diet (a source of phytoestrogens) and adiposity. This review considers some of the evidence collected to date.

Toxicological effects of the sunscreen UV filter, benzophenone-2, on planulae and in vitro cells of the coral, Stylophora pistillata

Benzophenone-2 (BP-2) is an additive to personal-care products and commercial solutions that protects against the damaging effects of ultraviolet light. BP-2 is an "emerging contaminant of concern" that is often released as a pollutant through municipal and boat/ship wastewater discharges and landfill leachates, as well as through residential septic fields and unmanaged cesspits. Although BP-2 may be a contaminant on coral reefs, its environmental toxicity to reefs is unknown. This poses a potential management issue, since BP-2 is a known endocrine disruptor as well as a weak genotoxicant. We examined the effects of BP-2 on the larval form (planula) of the coral, Stylophora pistillata, as well as its toxicity to in vitro coral cells. BP-2 is a photo-toxicant; adverse effects are exacerbated in the light versus in darkness. Whether in darkness or light, BP-2 induced coral planulae to transform from a motile planktonic state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of BP-2. BP-2 is a genotoxicant to corals, exhibiting a strong positive relationship between DNA-AP lesions and increasing BP-2 concentrations. BP-2 exposure in the light induced extensive necrosis in both the epidermis and gastro dermis. In contrast, BP-2 exposure in darkness induced autophagy and autophagic cell death.The LC50 of BP-2 in the light for an 8 and 24 hour exposure was 120 parts per million (ppm) and 165 parts per billion (ppb), respectively. The LC50s for BP-2 in darkness for the same time points were 144 parts per million and 548 parts per billion [corrected].