Exposure assessment of dairy cows to parabens using hair samples analysis

Parabens (PBs) are used as preservatives in various products. They pollute the environment and penetrate living organisms, showing endocrine disrupting activity. Till now studies on long-term exposure of farm animals to PBs have not been performed. Among matrices using in PBs biomonitoring hair samples are becoming more and more important. During this study concentration levels of methyl paraben (MeP), ethyl paraben (EtP), propyl paraben (PrP) butyl paraben (BuP) and benzyl paraben (BeP) were evaluated using liquid chromatography-mass spectrometry (LC-MS) in hair samples collected from dairy cows bred in the Kyrgyz Republic. MeP was noted in 93.8% of samples (with mean concentration levels 62.2 ± 61.8 pg/mg), PrP in 16.7% of samples (12.4 ± 6.5 pg/mg) and EtP in 8.3% of samples (21.4 ± 11.9 pg/mg). BuP was found only in one sample (2.1%) and BeP was not detected in any sample included in the study. Some differences in MeP concentration levels in the hair samples depending on district, where cows were bred were noted. This study has shown that among PBs, dairy cows are exposed mainly to MeP, and hair samples may be a suitable matrix for research on PBs levels in farm animals.

Exposure to environmental pollutants and genetic variants related to oxidative stress and xenobiotic metabolism-Association with prostate cancer

This study assessed whether genetic variants coding for certain enzymes involved in xenobiotic detoxification, antioxidant defences and DNA repair, along with exposure to environmental chemicals, were associated with an increased prostate cancer (PCa) risk. The study population consisted of 300 men (150 PCa cases and 150 controls) which underwent prostate biopsy as their serum prostate specific antigen (PSA) levels were greater than 4 ng/ml. Genetic variants in GSTM1, GSTP1, SOD2, CAT, GPX1, XRCC1 were determined and data for chemical exposures was obtained through a structured questionnaire and by biomonitoring in a subsample of cases and controls. High serum PSA levels were associated with a greater risk of PCa, while physical exercise appears to exert a protective effect against its development. In addition, elevated urinary levels of certain organic pollutants, such as benzo(a)pyrene (BaP), bisphenol A (BPA), and ethyl-paraben (EPB), were associated with an increased risk of PCa.

In vitro assessment of the antioxidative, toxicological and antimicrobial properties of battery of parabens

The aim of this study was to evaluate antioxidative features using 2,2-diphenyl-1-pycrylhydrazyl free radical (DPPH^•) scavenging method, bovine serum albumin (BSA)-binding properties with usage of spectrofluorimetric method, proliferative and cyto/genotoxic status by use of chromosome aberration test, and antimicrobial potential using broth microdilution method, followed by resazurin assay of benzyl-, isopropyl-, isobutyl and phenylparaben in vitro. Our results showed that all parabens had significant antiradical scavenger activity compared to p-hydroxybenzoic acid (PHBA) precursor. Higher mitotic index for benzyl-, isopropyl and isobutylparaben (250 µg/mL) in comparison with control was demonstrated. An increase in the frequency of acentric fragments in lymphocytes treated with benzylparaben and isopropylparaben (125 and 250 µg/mL), and isobutylparaben (250 µg/mL) was observed. Isobutylparaben (250 µg/mL) induced higher number of dicentric chromosomes. An increased number of minute fragments in lymphocytes exposed to benzylparaben (125 and 250 µg/mL) was found. A significant difference in the frequency of chromosome pulverization, between phenylparaben (250 µg/mL) and control, was detected. Benzylparaben (250 µg/mL) and phenylparaben (62.5 µg/mL) caused an increase in the number of apoptotic cells, while isopropylparaben (62.5, 125 and 250 µg/mL) and isobutylparaben (62.5 and 125 µg/mL) induced higher frequency of necrosis. Minimum inhibitory concentration (MIC) of tested parabens ranged 15.62-250 µg/mL for bacteria, and 125-500 µg/mL for the yeast. Minimum microbiocidal concentration ranged 31.25 to 500 µg/mL, and 250 to 1000 µg/mL in bacteria and fungi respectively. The lowest MICs for bacteria were observed for phenyl- (15.62 µg/mL) and isopropylparaben (31.25 µg/mL) against Enterococcus faecalis.

Pharmacokinetics of transdermal methyl-, ethyl-, and propylparaben in humans following single dermal administration

Parabens are common chemicals used as preservatives in foods, cosmetics, and personal care products. Although transdermal exposure to parabens occurs, studies on human pharmacokinetics (PK) following dermal exposure to parabens are scarce. In this study, the PK following dermal exposure to parabens was determined and compared with our previous findings on oral exposure. A paraben mixture cream containing 0.8% deuterated methyl-, ethyl-, and propylparaben (MeP-d₄ 0.26%; EtP-d₄ 0.26%, and PrP-d₄ 0.28%) was dermally applied to the whole arm of five male volunteers at a dose of 24 g/person over 30 min. Blood and urine samples were collected at several intervals over the course of 48 h to measure the levels of MeP-d₄, EtP-d₄, and PrP-d₄ and their conjugated metabolites using HPLC-MS/MS. As a result of non-compartmental analysis, the average peak values of total (sum of conjugated and unconjugated metabolites) MeP-d₄, EtP-d_4, and PrP-d₄ were reached at 7.8 h, 10.5 h, and 5.3 h, indicating a slower absorption rate compared to that of oral exposure (<2 h). The terminal elimination half-lives of MeP-d₄, EtP-d₄, and PrP-d₄ were 12.2 h, 12.0 h, and 9.3 h, respectively. Fractional urinary excretion (F_ue) of total MeP-d₄, EtP-d₄, and PrP-d₄ was 1.7%, 2.3%, and 1.9%, respectively. The F_ue of total and unconjugated PrP-d₄ following dermal exposure was five times lower and three times higher, respectively, compared with those after oral exposure, suggesting that PrP is relatively less metabolized to the conjugated form after dermal exposure. Taken together, dermal exposure to paraben leads to a longer apparent half-life and results in higher proportions of biologically active unconjugated parabens in the systemic circulation as compared to oral exposure. This study provides insights into the kinetic properties of parabens and their metabolites in humans.

Patient-Derived iPSCs Reveal Evidence of Telomere Instability and DNA Repair Deficiency in Coats Plus Syndrome

Coats plus (CP) syndrome is an inherited autosomal recessive condition that results from mutations in the conserved telomere maintenance component 1 gene (CTC1). The CTC1 protein functions as a part of the CST protein complex, a protein heterotrimer consisting of CTC1-STN1-TEN1 which promotes telomere DNA synthesis and inhibits telomerase-mediated telomere elongation. However, it is unclear how CTC1 mutations may have an effect on telomere structure and function. For that purpose, we established the very first induced pluripotent stem cell lines (iPSCs) from a compound heterozygous patient with CP carrying deleterious mutations in both alleles of CTC1. Telomere dysfunction and chromosomal instability were assessed in both circulating lymphocytes and iPSCs from the patient and from healthy controls of similar age. The circulating lymphocytes and iPSCs from the CP patient were characterized by their higher telomere length heterogeneity and telomere aberrations compared to those in control cells from healthy donors. Moreover, in contrast to iPSCs from healthy controls, the high levels of telomerase were associated with activation of the alternative lengthening of telomere (ALT) pathway in CP-iPSCs. This was accompanied by inappropriate activation of the DNA repair proteins γH2AX, 53BP1, and ATM, as well as with accumulation of DNA damage, micronuclei, and anaphase bridges. CP-iPSCs presented features of cellular senescence and increased radiation sensitivity. Clonal dicentric chromosomes were identified only in CP-iPSCs after exposure to radiation, thus mirroring the role of telomere dysfunction in their formation. These data demonstrate that iPSCs derived from CP patients can be used as a model system for molecular studies of the CP syndrome and underscores the complexity of telomere dysfunction associated with the defect of DNA repair machinery in the CP syndrome.

Occurrence and human exposure assessment of parabens in water sources in Osun State, Nigeria

Parabens are chemicals extensively used in pharmaceuticals, cosmetics, personal hygiene and food products as preservatives. They are classified as emerging contaminants with endocrine-disrupting capability. In this study, the concentrations of Methylparaben (MeP), Ethylparaben (EtP), Propylparaben (PrP) and Butylparaben (BuP) were obtained from groundwater, surface-water and packaged water samples collected from urban and rural areas of Osun State, Nigeria using HPLC-UV equipment. Data obtained were subjected to descriptive (Mean ± SD), inferential (Kruskal-Wallis test) and multivariate analyses. MeP had the highest average concentration of 163 and 68 μg L^-1 in surface water and groundwater respectively while concentrations of MeP, EtP, PrP and BuP were higher than previously reported in other countries. Methylparaben had the highest detection frequencies (88.0 and 50.0%) followed by BuP (69.0 and 50.0%) in surface water and groundwater respectively. No significant difference was observed for concentrations of parabens in groundwater samples in urban and rural sampling sites, suggesting that people living around these sites are equally exposed to any health implications from the use of paraben-polluted potable water. Principal Component Analysis (PCA) data suggest that the pairs MeP & EtP, PrP & BuP (in surface water samples) and MeP, EtP, & PrP (in groundwater samples) are from similar pollution sources. Ecological risk assessment using Algae, Fish, and Daphnia suggests Daphnia as the most sensitive organism while BuP and PrP show the highest health risk. Human exposure assessment showed that higher overall median estimated daily intake (EDI) values for groundwater were observed in infants (1.71 μg kg^-1 bw day^-1, ∑PBs) compared to toddlers (1.03 μg kg^-1 bw day^-1, ∑PBs), children (0.64 μg kg^-1 bw day^-1, ∑PBs), teenagers (0.51 μg kg^-1 bw day^-1, ∑PBs) and adults (0.62 μg kg^-1 bw day^-1, ∑PBs). Although these values are below limits set in a few countries, potential bioaccumulation could lead to severe health consequences.

Lung Fibroblasts from Idiopathic Pulmonary Fibrosis Patients Harbor Short and Unstable Telomeres Leading to Chromosomal Instability

Idiopathic pulmonary fibrosis (IPF) is associated with several hallmarks of aging including telomere shortening, which can result from germline mutations in telomere related genes (TRGs). Here, we assessed the length and stability of telomeres as well as the integrity of chromosomes in primary lung fibroblasts from 13 IPF patients (including seven patients with pathogenic variants in TRGs) and seven controls. Automatized high-throughput detection of telomeric FISH signals highlighted lower signal intensity in lung fibroblasts from IPF patients, suggesting a telomere length defect in these cells. The increased detection of telomere loss and terminal deletion in IPF cells, particularly in TRG-mutated cells (IPF-TRG), supports the notion that these cells have unstable telomeres. Furthermore, fibroblasts from IPF patients with TRGs mutations exhibited dicentric chromosomes and anaphase bridges. Collectively, our study indicates that fibroblasts from IPF patients exhibit telomere and chromosome instability that likely contribute to the physiopathology.

Endocrine disruptor chemicals. A review of their effects on male reproduction and antioxidants as a strategy to counter it

Endocrine disruptor chemicals are exogenous molecules that generate adverse effects on human health by destabilizing the homeostasis of endocrine system and affecting directly human reproductive system by inhibiting or activating oestrogenic or androgenic receptors. Endocrine disruptor chemicals generate transgenerational epigenetic problems, besides being associated with male infertility. Epidemiological data indicate that the increase in reproductive problems in males in the last 50 years is correlated with the increase of endocrine disrupting chemicals in the environment, being associated with a decrease in semen quality and direct effects on spermatozoa, such as alterations in motility, viability and acrosomal reaction, due to the generation of oxidative stress, and have also been postulated as a possible cause of testicular dysgenesis syndrome. Diverse antioxidants, such as C and E vitamins, N-acetylcysteine, selenium and natural vegetable extracts, are among the alternatives under study to counter the effects of endocrine disruptor chemicals. In some cases, the usage of them has given positive results and the opposite in others. In this review, we summarize the recent information about the effects of endocrine disruptor chemicals on male reproduction, on sperm cells, and the results of studies that have tested antioxidants as a strategy to diminish their harmful effects.

Toxicity and removal of parabens from water: A critical review

Parabens are biocides used as preservatives in food, cosmetics and pharmaceuticals. They possess antibacterial and antifungal activity due to their ability to disrupt cell membrane and intracellular proteins, and cause changes in enzymatic activity of microbial cells. Water, one of our most valuable natural resource, has become a huge reservoir for parabens. Halogenated parabens from chlorination/ozonation of water contaminated with parabens have shown to be even more persistent in water than other types of parabens. Unfortunately, there is dearth of data on their (halogenated parabens) presence and fate in groundwater which serves as a major source of drinking water for a huge population in developing countries. An attempt to neglect the presence of parabens in water will expose man to it through ingestion of contaminated food and water. Although there are reviews on the occurrence, fate and behaviour of parabens in the environment, they largely omit toxicity and removal aspects. This review therefore, presents recent reports on the acute and chronic toxicity of parabens, their estrogenic agonistic and antagonistic activity and also their relationship with antimicrobial resistance. This article further X-rays several techniques that have been employed for the removal of parabens in water and their drawbacks including adsorption, biodegradation, membrane technology and advanced oxidation processes (AOPs). The heterogeneous photocatalytic process (one of the AOPs) appears to be more favoured for removal of parabens due to its ability to mineralize parabens in water. However, more work is needed to improve this ability of heterogeneous photocatalysts. Perspectives that will be relevant for future scientific studies and which will drive policy shift towards the presence of parabens in our drinking waters are also offered. It is hoped that this review will elicit some spontaneous actions from water professionals, scientists and policy makers alike that will provide more data, effective technologies, and adaptive policies that will address the growing threat of the presence of parabens in our environment with respect to human health.

Correlation study of parabens in urine, serum, and seminal plasma of adult men in Beijing, China

The adverse effects of parabens raise concerns about their extensive use as preservatives in consumer products, especially in cosmetics. Until now, their distribution and excretion in humans have attracted little attention. Here, we quantified various agents including, for the first time, methyl-; ethyl-; n-propyl-; n-butyl-, and i-butylparaben (MeP, EtP, PrP, n-BuP, i-BuP); methyl- and ethyl-protocatechuate (OH-MeP and OH-EtP); hydroxybenzoic acid (4-HB); and 3,4-dihydroxybenzoic acid (3,4-DHB) in urine, serum, and seminal plasma samples from 50 healthy Chinese men in Beijing, China. Urine paraben concentrations were 1-2 orders of magnitudes higher than those in serum and seminal plasma. MeP and PrP were predominant and correlated with each other in the urine, serum, and seminal plasma. In urine, we observed a significant correlation between MeP and OH-MeP; EtP and OH-EtP; and 4-HB and 3,4-DHB concentrations. All these results provide new information on parabens as biomarkers for the assessment of exposure.

Safety Testing of Cosmetic Products: Overview of Established Methods and New Approach Methodologies (NAMs)

Cosmetic products need to have a proven efficacy combined with a comprehensive toxicological assessment. Before the current Cosmetic regulation N°1223/2009, the 7th Amendment to the European Cosmetics Directive has banned animal testing for cosmetic products and for cosmetic ingredients in 2004 and 2009, respectively. An increasing number of alternatives to animal testing has been developed and validated for safety and efficacy testing of cosmetic products and cosmetic ingredients. For example, 2D cell culture models derived from human skin can be used to evaluate anti-inflammatory properties, or to predict skin sensitization potential; 3D human skin equivalent models are used to evaluate skin irritation potential; and excised human skin is used as the gold standard for the evaluation of dermal absorption. The aim of this manuscript is to give an overview of the main in vitro and ex vivo alternative models used in the safety testing of cosmetic products with a focus on regulatory requirements, genotoxicity potential, skin sensitization potential, skin and eye irritation, endocrine properties, and dermal absorption. Advantages and limitations of each model in safety testing of cosmetic products are discussed and novel technologies capable of addressing these limitations are presented.

In Vitro Three-Dimensional Liver Models for Nanomaterial DNA Damage Assessment

Whilst the liver possesses the ability to repair and restore sections of damaged tissue following acute injury, prolonged exposure to engineered nanomaterials (ENM) may induce repetitive injury leading to chronic liver disease. Screening ENM cytotoxicity using 3D liver models has recently been performed, but a significant challenge has been the application of such in vitro models for evaluating ENM associated genotoxicity; a vital component of regulatory human health risk assessment. This review considers the benefits, limitations, and adaptations of specific in vitro approaches to assess DNA damage in the liver, whilst identifying critical advancements required to support a multitude of biochemical endpoints, focusing on nano(geno)toxicology (e.g., secondary genotoxicity, DNA damage, and repair following prolonged or repeated exposures).

Parabens in urine of children and adolescents in Germany - human biomonitoring results of the german environmental survey 2014-2017 (GerES V)

Parabens are antimicrobial preservatives used in a wide range of consumer products such as personal care products, cosmetics, pharmaceuticals, and food. Consequently, the general population is ubiquitously exposed to these substances via dermal absorption, ingestion, and inhalation. Parabens promote estrogenic activity and are hence under assessment as endocrine disrupting substances. Urine samples from 3- to 17-year-old children and adolescents (N = 516) living in Germany were analysed for concentrations of nine parabens in the population representative German Environmental Survey for Children and Adolescents 2014-2017 (GerES V). Detection rates and urinary concentrations of the parabens decreased with increasing length of the alkyl chain. Methyl paraben was quantified in 97% of the samples with a geometric mean (GM) concentration of 7.724 μg/L (6.714 μg/g_creatinine), ethyl paraben was quantified in 69% (GM: 0.943 μg/L and 0.825 μg/g_crea), and n-propyl paraben in 31% (GM: 0.563 μg/L and 0.493 μg/g_crea). Concentrations of iso-propyl paraben, butyl paraben, iso-butyl paraben, and benzyl paraben were below the limit of quantification in most samples. Pentyl paraben and heptyl paraben were not detected in any of the samples. Paraben concentrations in urine were found to be associated with frequent usage of leave-on personal care products and cosmetics. Cumulative exposure to parabens (back-calculated daily intakes, expressed as hazard index) was found to be on a level raising concern in up to 14% of the population, mainly driven by n-propyl paraben, and depending on the level of conservativeness and point-of departures used for calculation.

Toxicological assessment and developmental abnormalities induced by butylparaben and ethylparaben exposure in zebrafish early-life stages

Toxicological effects of butylparaben (BuP) and ethylparaben (EtP) on zebrafish (Danio rerio) early-life stages are not well established. The present study evaluated, using zebrafish embryos and larvae, the toxicity of BuP and EtP through benchmark dose (BMD) approach. BuP was more toxic than EtP to zebrafish larvae. In fact, Lethal Concentration 50 (LC50) values at 96 h post-fertilization (hpf) for BuP and EtP were 2.34 mg/L and 20.86 mg/L, respectively. Indeed, BMD confidence interval (lower bound (BMDL) - upper bound (BMDU) was 0.91-1.92 mg/L for BuP and 10.8-17.4 mg/L for EtP. Zebrafish embryos exposed to 1 mg/L, 2.5 mg/L of BuP and 5 mg/L, 10 mg/L, 20 mg/L, 30 mg/L of EtP showed several developmental abnormalities and teratological effects compared to negative control. Exposed zebrafish developed reduced heartbeat, reduction in blood circulation, blood stasis, pericardial edema, deformed notochord and misshaped yolk sac. Embryos exposed to the highest concentrations of the chemicals (2.5 mg/L of BuP, 10 mg/L, 20 mg/L and 30 mg/L of EtP) showed the developmental abnormalities at 48 hpf while those treated with 1 mg/L of BuP and 10 mg/L of EtP reported behavioral changes at 72 hpf, including trembling of head, pectoral fins and spinal cord. This research identified the lethal and sublethal effects of BuP and EtP in zebrafish early-life stages and could be helpful to elucidate the developmental pathways of toxicity of parabens.

A Novel HPLC Method for Simultaneous Determination of Methyl, Ethyl, n-propyl, Isopropyl, n-butyl, Isobutyl and Benzyl Paraben in Pharmaceuticals and Cosmetics

INTRODUCTION

The alkyl esters of p-hydroxybenzoic acid at the C-4 position, "the parabens," including methyl, ethyl, propyl, and butyl, are widely used as antimicrobial preservatives in foods, cosmetics, and pharmaceuticals. Official regulations on the use of these compounds make their analysis essential for the estimation of their exposure.

METHODS

On this basis, the presented study was realized to develop a simple, selective and cheap high-performance liquid chromatographic method for the quantitative determination of methylparaben, ethylparaben (EP), n-propyl paraben (NPP), isopropyl paraben (IPP), n-butyl paraben (NBP), isobutyl paraben (IBP) and benzyl paraben (BP) in pharmaceuticals and cosmetic products.

RESULTS

The chromatographic separation of the analytes was achieved under flow rate gradient elution conditions using a C18-bonded core-shell silica particle column (2.6 μm particle size, 150 × 3.0 mm from Phenomenex Co.). The samples were injected into the system as aliquots of 1.0 μL, and the compounds were detected by using a photodiode array detector set at 254 nm wavelength. With this technique, seven paraben derivatives can be determined in the concentration range of 250-2000 ng/mL. The recovery of the method is in the range of 99.95-13.84%, and the RSD is at a maximum value of 3.95%.

CONCLUSION

The proposed method was fully validated and successfully applied to different pharmaceutical and cosmetic samples (n=16), including syrups, suspensions, oral sprays, gels, etc. At least one paraben derivative was detected in six samples and was determined quantitatively. The maximum amount of a paraben derivative found in the analyzed samples was 321.7 ng/mL, which was MP. To the best of our knowledge, this is the first LC method, which is applicable both on pharmaceutical and cosmetic samples.

Ethylparaben induces apoptotic cell death in human placenta BeWo cells via the Caspase-3 pathway

Parabens are generally used as preservatives in foods, pharmaceuticals, and various other commercial products. Among them, ethylparaben has weaker estrogenic characteristics than endogenous estrogen. However, growing evidence indicates that ethylparaben has an adverse effect on various human tissues. Here, we investigated whether ethylparaben induces cell death by affecting cell viability, cell proliferation, cell cycle, and apoptosis using the human placenta cell line BeWo. Ethylparaben significantly decreased cell viability in a dose-dependent manner. It caused cell cycle arrest at sub-G1 by reducing the expression of cyclin D1, whereas it decreased the cell proportion at the G0/G1 and S phases. Furthermore, we verified that ethylparaben induces apoptotic cell death by enhancing the activity of Caspase-3. Taken together, our results suggest that ethylparaben exerts cytotoxic effects in human placental BeWo cells via cell cycle arrest and apoptotic pathways.

Independent Mechanisms Lead to Genomic Instability in Hodgkin Lymphoma: Microsatellite or Chromosomal Instability †

Background: Microsatellite and chromosomal instability have been investigated in Hodgkin lymphoma (HL). Materials and Methods: We studied seven HL cell lines (five Nodular Sclerosis (NS) and two Mixed Cellularity (MC)) and patient peripheral blood lymphocytes (100 NS-HL and 23 MC-HL). Microsatellite instability (MSI) was assessed by PCR. Chromosomal instability and telomere dysfunction were investigated by FISH. DNA repair mechanisms were studied by transcriptomic and molecular approaches. Results: In the cell lines, we observed high MSI in L428 (4/5), KMH2, and HDLM2 (3/5), low MSI in L540, L591, and SUP-HD1, and none in L1236. NS-HL cell lines showed telomere shortening, associated with alterations of nuclear shape. Small cells were characterized by telomere loss and deletion, leading to chromosomal fusion, large nucleoplasmic bridges, and breakage/fusion/bridge (B/F/B) cycles, leading to chromosomal instability. The MC-HL cell lines showed substantial heterogeneity of telomere length. Intrachromosmal double strand breaks induced dicentric chromosome formation, high levels of micronucleus formation, and small nucleoplasmic bridges. B/F/B cycles induced complex chromosomal rearrangements. We observed a similar pattern in circulating lymphocytes of NS-HL and MC-HL patients. Transcriptome analysis confirmed the differences in the DNA repair pathways between the NS and MC cell lines. In addition, the NS-HL cell lines were radiosensitive and the MC-cell lines resistant to apoptosis after radiation exposure. Conclusions: In mononuclear NS-HL cells, loss of telomere integrity may present the first step in the ongoing process of chromosomal instability. Here, we identified, MSI as an additional mechanism for genomic instability in HL.