Research progress on food-derived antioxidants for alleviating toxicity of endocrine disrupting chemicals / 环境与职业医学

Endocrine disrupting chemicals (EDCs) are a class of chemical substances widely present in daily-life environment, and can enter human body through various pathways, posing a threat to reproductive development and health. Oxidative stress (OS) is one of the most important fundamental mechanisms underlying the reproductive toxicity of EDCs. Numerous studies have found that exposure to EDCs can increase the levels of reactive oxygen species (ROS) in human reproductive system and reduce the activity and quantity of multiple enzymatic antioxidants, leading to oxidative stress and inducing damage to the reproductive system at various levels such as DNA and cells. Many research results have shown that supplementing food-derived non-enzymatic antioxidants can reduce ROS levels and increase the activity of enzymatic antioxidants, thereby reduce OS levels, and further repair EDCs-induced reproductive damage. In addition, many food-derived antioxidants are important elements involved in reproductive physiological activities and have protective effects on reproductive health. This paper summarized the reproductive toxicity of EDCs, including damage to reproductive cells, interference with hormone action, and influence on reproductive-related epigenetic regulation, elaborated the relationship between OS and reproductive toxicity of EDCs, and further summarized the alleviating effects and related mechanisms of food-derived antioxidants such as vitamins, trace elements, and plant polyphenols and pigments against reproductive toxicity of EDCs, aiming to provide a theoretical and scientific basis for prevention and treatment against reproductive toxicity of EDCs.

Research progress on the correlation between early life adversity and the puberty initiation / 中华实用儿科临床杂志

Earlier onset of puberty has become a worldwide trend.A large number of epidemiologic and animal experiment evidences have indicated that environmental changes in the early life may influence development plasticity and cause structural and functional changes, which are correlated with adult chronic diseases.The impact of fluctuations in environmental factors on the reproductive phenotype of offspring has been well concerned in recent years.This review summarizes the influences of nutritional state, endocrine disrupting chemicals, hormonal perturbation and stressful events during the prenatal and early childhood on the puberty initiation, especially neuroendocrine changes in puberty, thus providing a new idea for the prevention and control of pubertal disorders.

The effect of Endocrine disrupting chemicals on myocardial fibrosis and related mechanism / 中华劳动卫生职业病杂志

Endocrine-disrupting chemicals (EDCs) an exogenous agent that interferes with the synthesis, secretion, transport, binding, action, or can mimic the occurrence of natural hormones that damage for the balance of homeostasis. Exposure to EDCs results in damage to human health that may persist in the long term. In recent years, accumulative evidence has demonstrated that EDCs also play a pivotal role in the onset and development of myocardial fibrosis, including heart failure, hypertension and vascular stiffening. Studies indicate that EDCs plays the negative effects of the cardiovascular system, however, EDCs-induced toxicity on heart remains unclear. This review summarized EDCs-induced myocardial fibrosis, and discuss the possible mechanisms of myocardial fibrosis induced by EDCs. This paper could provide further understandings for prevention, diagnosis and treatment of myocardial fibrosis.

Research progress on reproductive toxicity and reproductive system tumors induced by environmental endocrine disrupting chemicals / 环境与职业医学

Environmental endocrine disrupting chemicals are a kind of exogenous chemicals that generally exist in the environment, and can disturb the endocrine homeostasis and adversely affect reproductive, immune, neurological, and other functions after entering the body, among which the damage to the reproductive system is the most significant one. Studies have confirmed that the long-term exposure to environmental endocrine disrupting chemicals have irreversible and harmful effects on primordial germ cell growth, reproductive organ development, and reproductive endocrine regulation, and also have obvious correlations with the occurrence and development of various reproductive system tumors. This paper reviewed various reproductive toxicities induced by common environmental endocrine disrupting chemicals in the developmental and reproductive stages, and associated mechanisms involved in the occurrence and development of reproductive system tumors.

Ecotoxicological risk assessment due to the presence of bisphenol A and caffeine in surface waters in the Sinos River Basin - Rio Grande do Sul - Brazil / Risco ecotoxicológico devido à presença de bisfenol A e cafeína nas águas superficiais na Bacia do Rio Sinos - Rio Grande do Sul - Brasil

Abstract Bisphenol A (BPA) is an emerging contaminant, regularly detected in aquatic ecosystems, considered as an endocrine disrupting compound (EDC). Caffeine is another chemical related to human activity, often found in surface waters. The objective of this study was to evaluate the ecotoxicological risk due to BPA and caffeine in water samples from the Sinos River basin, Rio Grande do Sul, Brazil. Water samples were collected at three sites monthly from May 9 th, 2016 to April 11th, 2017 (n = 36). BPA concentrations in water samples collected were in the range of not detected to 517 ng L-1 and caffeine concentrations in the range of 41.7 to 28,439.6 ng L-1. The concentration of BPA in the analyzed samples had a moderate correlation with caffeine (rs = 0.402). High ecotoxicological risk for BPA was characterized in 77.77% of samples, with 11.11% presenting medium and 11.1% presenting low risk. For caffeine 13.9%, 50% and 36.11% of the samples presented high, medium and low risk, respectively. Caffeine concentrations in water can be used as predictors of BPA concentrations above 10 ng L-1, the lower concentration of ecotoxicological risk, with specificity of 66.7% and sensitivity of 70.4%. The assessment of aquatic risks has shown that both investigated compounds pose risks to organisms in the studied surface waters, mouth of the Pampa stream, mouth of the Luiz Rau stream and catchment point for public supply in Lomba Grande.

Resumo Bisfenol A (BPA) é um contaminante emergente regularmente detectado em ecossistemas aquáticos, é considerado um agente modificador endócrino (EDC). Além disso, outro produto químico relacionado com atividade humana, encontrado com frequência nas águas superficiais, é a cafeína. O objetivo deste estudo foi avaliar a ocorrência de risco ecotoxicológico devido a BPA e cafeína em amostras de água da Bacia Hidrográfica do Rio Sinos, Rio Grande do Sul, Brasil. Foram coletadas amostras de água em três locais mensalmente no período de 9 de maio de 2016 a 11 de abril de 2017 (n = 36). As concentrações de BPA em amostras de água coletadas estavam na faixa de não detectada a 517 ng L-1 e concentrações de cafeína na faixa de 41,7 a 28,439,6 ng L-1. A concentração de BPA nas amostras analisadas apresentou correlação moderada com a cafeína (rs = 0,402). Alto risco ecotoxicológico para BPA foi caracterizado em 77,77% das amostras, com 11,11% apresentando médio e 11,1% apresentando baixo risco. Para cafeína 13,9%, 50% e 36,11% das amostras apresentaram risco alto, médio e baixo, respectivamente. Concentrações de cafeína em água podem ser utilizadas como preditoras de concentrações de BPA acima de 10 ng L-1, menor concentração de risco ecotoxicológico, com especificidade de 66,7% e sensibilidade de 70,4%. A avaliação dos riscos aquáticos revelou que ambos os compostos investigados representam risco para os organismos nas águas superficiais estudadas, foz do arroio Pampa, foz do arroio Luiz Rau e ponto de captação para abastecimento público em Lomba Grande.

The research advance on the effects of environmental endocrine disruptors on the adolescent girls / 中华内分泌代谢杂志

Endocrine-disrupting chemicals ( EDCs ) are widely found in people's daily supplies or environments. The individuals in the world contact with these substances through different pathways. Adolescent-developed individuals are more sensitive to these substances. The integration of many environmental factors through epigenetic modification affects the starting age of puberty. Although there are various related studies, it is impossible for humans to contact only a single substance, and there is still much doubt about the additive effect of EDCs mixtures with similar mechanisms of action. Therefore, analytical scientists, molecular biologists, toxicologists, epidemiologists, endocrinologists, gynecologists, obstetricians, and oncologists are required to conduct multidisciplinary research to address and to discuss all the scientific results. It may have far-reaching implications for formulating the prevention strategies and individualized health plans.

Analysis of individual and combined estrogenic effects of bisphenol, nonylphenol and diethylstilbestrol in immature rats with mathematical models

BACKGROUND@#Traditional toxicological studies focus on individual compounds. However, this single-compound approach neglects the fact that the mixture exposed to human may act additively or synergistically to induce greater toxicity than the single compounds exposure due to their similarities in the mode of action and targets. Mixture effects can occur even when all mixture components are present at levels that individually do not produce observable effects. So the individual chemical effect thresholds do not necessarily protect against combination effects, an understanding of the rules governing the interactive effects in mixtures is needed. The aim of the study was to test and analyze the individual and combined estrogenic effects of a mixture of three endocrine disrupting chemicals (EDCs), bisphenol A (BPA), nonylphenol (NP) and diethylstilbestrol (DES) in immature rats with mathematical models.@*METHOD@#In the present study, the data of individual estrogenic effects of BPA, NP and DES were obtained in uterotrophic bioassay respectively, the reference points for BPA, NP and DES were derived from the dose-response ralationship by using the traditional no observed adverse effect (NOAEL) or lowest observed adverse effect level (LOAEL) methods, and the benchmark dose (BMD) method. Then LOAEL values and the benchmark dose lower confidence limit (BMDL) of single EDCs as the dose design basis for the study of the combined action pattern. Mixed prediction models, the 3 × 2 factorial design model and the concentration addition (CA) model, were employed to analyze the combined estrogenic effect of the three EDCs.@*RESULTS@#From the dose-response relationship of estrogenic effects of BPA, NP and DES in the model of the prepuberty rats, the BMDL(NOAEL) of the estrogenic effects of BPA, NP and DES were 90(120) mg/kg body weight, 6 mg/kg body weight and 0.10(0.25) μg/kg body weight, and the LOAEL of the the estrogenic effects of three EDCs were 240 mg/kg body weight, 15 mg/kg body weight and 0.50 μg/kg body weight, respectively. At BMDL doses based on the CA concept and the factorial analysis, the mode of combined effects of the three EDCs were dose addition. Mixtures in LOAEL doses, NP and DES combined effects on rat uterine/body weight ratio indicates antagonistic based on the CA concept but additive based on the factorial analysis. Combined effects of other mixtures are all additive by using the two models.@*CONCLUSION@#Our results showed that CA model provide more accurate results than the factorial analysis, the mode of combined effects of the three EDCs were dose addition, except mixtures in LOAEL doses, NP and DES combined effects indicates antagonistic effects based on the CA model but additive based on the factorial analysis. In particular, BPA and NP produced combination effects that are larger than the effect of each mixture component applied separately at BMDL doses, which show that additivity is important in the assessment of chemicals with estrogenic effects. The use of BMDL as point of departure in risk assessment may lead to underestimation of risk, and a more balanced approach should be considered in risk assessment.

Early-life exposure to endocrine-disrupting chemicals and pubertal development in girls

Over the last decades, the onset of puberty in girls has occurred earlier, but the tempo of pubertal progression has been relatively slower, resulting in a younger age at puberty onset without a change in age at menarche. Sufficient energy availability and adiposity contribute to early pubertal development, and environmental factors, such as endocrine-disrupting chemicals (EDCs), may affect not only the control of energy balance, but also puberty and reproduction. EDCs are hormonally active substances that can perturb puberty by acting both peripherally on target organs, such as adipose tissue or adrenal glands, and/or centrally on the hypothalamic-pituitary-gonadal (HPG) axis. Depending on whether the exposure takes place earlier during fetal and neonatal life or later during early childhood, EDCs can lead to different outcomes through different mechanisms. Evidence of associations between exposures to EDCs and altered pubertal timing makes it reasonable to support their relationship. However, human epidemiologic data are limited or inconsistent and cannot provide sufficient evidence for a causal relationship between EDC exposure and changes in pubertal timing. Further investigation is warranted to determine the overall or different effects of EDCs exposure during prenatal or childhood windows on pubertal milestones and to reveal the underlying mechanisms, including epigenetic marks, whereby early-life exposure to EDCs affect the HPG-peripheral tissue axis.

Relationship between triclosan exposure and thyroid hormones: the Second Korean National Environmental Health Survey (2012–2014)

BACKGROUND: 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan) is used as an antiseptic and is a potential endocrine-disrupting chemical that can affect thyroid hormone levels. This study evaluated the relationship between triclosan exposure and thyroid hormones. METHODS: Data from the second Korean National Environmental Health Survey (2012–2014) were analyzed. Triclosan exposure was evaluated using urinary triclosan concentrations and classified into 2 groups: ‘below detection (< limit of detection [LOD])’ vs. ‘detected (≥ LOD).’ Multiple linear regression analysis was conducted to determine the relationship between triclosan exposure and the serum thyroid hormone concentrations, adjusting for age, body mass index, urinary creatinine, and smoking status. RESULTS: When grouped by sex, triclosan exposure was positively associated with the serum thyroid-stimulating hormone (TSH) concentrations in females with marginal significance (β = 0.066, p = 0.058). However, no significant association was identified between triclosan exposure and serum total triiodothyronine and thyroxine in both males and females, and TSH in males. CONCLUSIONS: This study is the first human study to evaluate the relationship between triclosan exposure and serum thyroid hormone concentrations in the Korean population. There was suggestive positive association between triclosan exposure and the serum TSH in females. Further studies need to evaluate the relationship between long-term exposure to low-dose triclosan and thyroid hormones.

Oxidação de fármacos por cloro e formação de subprodutos em amostras aquosas em escala de bancada / Pharmaceuticals oxidation by chlorine and byproducts formation in aqueous matrices in bench scale

RESUMO Fármacos e desreguladores endócrinos são encontrados em águas naturais brasileiras, incluindo alguns mananciais de abastecimento, também em função da baixa cobertura de coleta e tratamento de esgotos no Brasil. Nesse cenário, o presente trabalho intentou avaliar a remoção de três fármacos - sulfametoxazol (SMX), diclofenaco (DCF) e 17β-estradiol (E2) - em água destilada por meio da oxidação com cloro (hipoclorito de sódio), variando-se a dose de cloro e o tempo de contato em ensaios de batelada. As soluções cloradas foram analisadas, ainda, por cromatografia acoplada à espectrometria de massas para identificação de eventuais subprodutos de oxidação. Para tempo de contato de 10 min e dose de cloro de 1,5 mg.L-1, foi observada remoção média de 61% para DCF, 36% para E2 e 33% para SMX. Apenas para o DCF verificou-se diferença estatisticamente significativa (α=0,05) para dose de cloro de 3,0 mg.L-1. A oxidação seguiu modelo cinético de pseudossegunda ordem, com valores de k2 de 0,0168 L.µg.min-1 para SMX (para ambas doses testadas), de 0,0133 e 0,0798 L.µg.min-1 para DCF, e de 0,0326 e 0,0289 L.µg.min-1 para E2, para doses de cloro de 1,5 e 3,0 mg.L-1, respectivamente. Por fim, verificou-se que o aumento do tempo de contato favoreceu a oxidação dos fármacos, ainda que com a perspectiva de formação de subprodutos para SMX e E2.

ABSTRACT Pharmaceuticals and endocrine disrupting compounds are found in Brazilian natural waters, including some water sources for public supply, also due to the low coverage of sewage collection and treatment in Brazil. This study investigated the removal of three pharmaceutical compounds - sulfamethoxazole (SMX), diclofenac (DCF) and 17β-estradiol (E2) - from aqueous solutions by means of chlorine oxidation (sodium hypochlorite) by varying the dose of chlorine and contact time in batch tests. The chlorine solutions were examined by chromatography attached to the mass spectrometry in order to identify the oxidation by-products. For 10 min contact time, mean removal values of 61% were observed for DCF; 36% for E2; and 33% for SMX, when the chlorine dose was 1.5 mg L-1. Just for DCF there was a statistically significant difference (α=0.05) in the removal efficiency when increasing the chlorine dose to 3.0 mg.L-1. The oxidation followed the kinetic model of pseudo-second order, with k2 values of 0.0168 L.µg.min-1 for SMX (at both chlorine doses tested); 0.0133 and 0.0798 L.µg.min-1 to DCF; and 0.0326 and 0.0289 L.µg.min-1 to the E2 at chlorine doses of 1.5 and 3.0 mg L-1, respectively. Finally, it was verified that an increase of the contact time favored the oxidation of all pharmaceuticals tested, although with the perspective of by-products formation for SMX and E2.

Early-life exposure to endocrine disrupting chemicals associates with childhood obesity

Increasing prevalence of childhood obesity poses threats to the global health burden. Because this rising prevalence cannot be fully explained by traditional risk factors such as unhealthy diet and physical inactivity, early-life exposure to endocrine disrupting chemicals (EDCs) is recognized as emerging novel risk factors for childhood obesity. EDCs can disrupt the hormone-mediated metabolic pathways, affect children’s growth and mediate the development of childhood obesity. Many organic pollutants are recently classified to be EDCs. In this review, we summarized the epidemiological and laboratory evidence related to EDCs and childhood obesity, and discussed the possible mechanisms underpinning childhood obesity and early-life exposure to non-persistent organic pollutants (phthalates, bisphenol A, triclosan) and persistent organic pollutants (dichlorodiphenyltrichloroethane, polychlorinated biphenyls, polybrominated diphenyl ethers, per- and polyfluoroalkyl substances). Understanding the relationship between EDCs and childhood obesity helps to raise public awareness and formulate public health policy to protect the youth from exposure to the harmful effects of EDCs.

Evidence of the Possible Harm of Endocrine-Disrupting Chemicals in Humans: Ongoing Debates and Key Issues

Evidence has emerged that endocrine-disrupting chemicals (EDCs) can produce adverse effects, even at low doses that are assumed safe. However, systemic reviews and meta-analyses focusing on human studies, especially of EDCs with short half-lives, have demonstrated inconsistent results. Epidemiological studies have insuperable methodological limitations, including the unpredictable net effects of mixtures, non-monotonic dose-response relationships, the non-existence of unexposed groups, and the low reliability of exposure assessment. Thus, despite increases in EDC-linked diseases, traditional epidemiological studies based on individual measurements of EDCs in bio-specimens may fail to provide consistent results. The exposome has been suggested as a promising approach to address the uncertainties surrounding human studies, but it is never free from these methodological issues. Although exposure to EDCs during critical developmental periods is a major concern, continuous exposure to EDCs during non-critical periods is also harmful. Indeed, the evolutionary aspects of epigenetic programming triggered by EDCs during development should be considered because it is a key mechanism for developmental plasticity. Presently, living without EDCs is impossible due to their omnipresence. Importantly, there are lifestyles which can increase the excretion of EDCs or mitigate their harmful effects through the activation of mitohormesis or xenohormesis. Effectiveness of lifestyle interventions should be evaluated as practical ways against EDCs in the real world.

Ecotoxicological risk assessment due to the presence of bisphenol A and caffeine in surface waters in the Sinos River Basin - Rio Grande do Sul - Brazil

Abstract Bisphenol A (BPA) is an emerging contaminant, regularly detected in aquatic ecosystems, considered as an endocrine disrupting compound (EDC). Caffeine is another chemical related to human activity, often found in surface waters. The objective of this study was to evaluate the ecotoxicological risk due to BPA and caffeine in water samples from the Sinos River basin, Rio Grande do Sul, Brazil. Water samples were collected at three sites monthly from May 9 th, 2016 to April 11th, 2017 (n = 36). BPA concentrations in water samples collected were in the range of not detected to 517 ng L-1 and caffeine concentrations in the range of 41.7 to 28,439.6 ng L-1. The concentration of BPA in the analyzed samples had a moderate correlation with caffeine (rs = 0.402). High ecotoxicological risk for BPA was characterized in 77.77% of samples, with 11.11% presenting medium and 11.1% presenting low risk. For caffeine 13.9%, 50% and 36.11% of the samples presented high, medium and low risk, respectively. Caffeine concentrations in water can be used as predictors of BPA concentrations above 10 ng L-1, the lower concentration of ecotoxicological risk, with specificity of 66.7% and sensitivity of 70.4%. The assessment of aquatic risks has shown that both investigated compounds pose risks to organisms in the studied surface waters, mouth of the Pampa stream, mouth of the Luiz Rau stream and catchment point for public supply in Lomba Grande.

Resumo Bisfenol A (BPA) é um contaminante emergente regularmente detectado em ecossistemas aquáticos, é considerado um agente modificador endócrino (EDC). Além disso, outro produto químico relacionado com atividade humana, encontrado com frequência nas águas superficiais, é a cafeína. O objetivo deste estudo foi avaliar a ocorrência de risco ecotoxicológico devido a BPA e cafeína em amostras de água da Bacia Hidrográfica do Rio Sinos, Rio Grande do Sul, Brasil. Foram coletadas amostras de água em três locais mensalmente no período de 9 de maio de 2016 a 11 de abril de 2017 (n = 36). As concentrações de BPA em amostras de água coletadas estavam na faixa de não detectada a 517 ng L-1 e concentrações de cafeína na faixa de 41,7 a 28,439,6 ng L-1. A concentração de BPA nas amostras analisadas apresentou correlação moderada com a cafeína (rs = 0,402). Alto risco ecotoxicológico para BPA foi caracterizado em 77,77% das amostras, com 11,11% apresentando médio e 11,1% apresentando baixo risco. Para cafeína 13,9%, 50% e 36,11% das amostras apresentaram risco alto, médio e baixo, respectivamente. Concentrações de cafeína em água podem ser utilizadas como preditoras de concentrações de BPA acima de 10 ng L-1, menor concentração de risco ecotoxicológico, com especificidade de 66,7% e sensibilidade de 70,4%. A avaliação dos riscos aquáticos revelou que ambos os compostos investigados representam risco para os organismos nas águas superficiais estudadas, foz do arroio Pampa, foz do arroio Luiz Rau e ponto de captação para abastecimento público em Lomba Grande.

Oxidative stress and histopathologic biomarkers of exposure to bisphenol-A in the freshwater fish, Ctenopharyngodon idella

ABSTRACT Bisphenol-A (BPA) belongs to the family of endocrine disrupting chemicals (EDCs) and it is used in the production of polycarbonate plastic and epoxy resins. The reproductive toxicity of BPA is well documented but it also exerts its toxic effects through multiple pathways especially by inducing a state of oxidative stress and causing damage to the vital organs. In the present study, histopathologic and oxidative damage caused by BPA in liver and kidneys of fresh water cyprinid, Ctenopharyngodon idella was evaluated. LC50 of BPA for Ctenopharyngodon idella was determined by probit regression analysis. Fish were exposed to a sublethal concentration of BPA i.e. 3.2 ppm (1/2 LC50) for 14 days. Histologic studies revealed that BPA caused degenerative changes in liver and kidneys and exposure of sublethal concentration of BPA caused oxidative damage in both organs. Lipid peroxidation significantly increased in liver and kidneys of treated group. Catalase activity and reduced glutathione content significantly decreased in the group exposed to BPA compared to control and glutathione-S-transferase activity increased significantly in both organs exposed to the sublethal concentration of BPA. From this study it is concluded that BPA caused toxic effects in fish species by changing oxidative balance and damaging the vital organs.

Prenatal and pubertal testosterone exposure imprint permanent modifications in the prostate that predispose to the development of lesions in old Mongolian gerbils / 亚洲男科学杂志(英文版)

The prostate is an accessory sex gland that develops under precise androgenic control. It is known that hormonal imbalance may disrupt its development predisposing this gland to develop diseases during aging. Although the hypothesis regarding earlier origins of prostate diseases was proposed many years ago, the mechanisms underlying this complex phenomenon are poorly understood. Therefore, the aim of this study was to evaluate the prostates of old male gerbils exposed to testosterone during intrauterine and postnatal life using morphological, biometrical, stereological, Kariometric, immunohistochemical, and immunofluorescence analyses. Our findings demonstrate that prenatal and pubertal exposure to testosterone increases the susceptibility to the development of prostate diseases during aging. The presence of a more proliferative gland associated with foci of adenomatous hyperplasia in animals exposed to testosterone during the prenatal and pubertal phase show that the utero life and the pubertal period are important phases for prostatic morphophysiology establishment, which is a determinant for the health of the gland during aging. Therefore, these findings reinforce the idea that prostate disease may result from hormonal disruptions in early events during prostate development, which imprint permanently on the gland predisposing it to develop lesions in later stages of life.

Influencing factors of early puberty / 国际儿科学杂志

Nearly half a century,an increasing number of studies have found that the puberty of human being is at early trends.Puberty is the process of physical changes involving reproductive system maturation and the acquisition of fertility,by the combination effects of nervous system,endocrine system and the environment.Pubertal timing is a relative concept and the process of pubertal development can be shown as early,timely or relatively late as compared with a reference group.This article mainly focuses on related influencing factors of pubertal timing including genetic factor,childhood obesity,growth pattern (intrauterine growth retardation,catchup growth,adiposity rebound),psychosocial stress (poor family emotional environment,father absence,international adoption),environmental endocrine disrupting chemicals with their mechanism and significance.The exploration of relevant risk factors of early puberty can provide scientific evidence for formulating relevant policies and targeted prevention.

Multi-target Determination of Trace Endocrine Disrupting Chemicals in Biota Using Ultra-high Performance Liquid Chromatography-Tandem Mass Spectrometry / 分析化学

An ultra-high performance liquid chromatography-tandem mass spectrometry ( UHPLC-MS/MS ) method was developed and validated for the simultaneous determination of 9 kinds of trace endocrine disrupting chemicals in biological samples using ultrasonic-assisted extraction followed by purification with gel permeation chromatography ( GPC) and silica gel columns. The sample extracts were purified by Bio beads S-X3 GPC columns with cyclohexane/ethyl acetate (1:1, V/V) as mobile phase, and the target compounds were eluted in the fraction of 12-28 mL retention volume. Electrospray ionization source operated in positive mode and atmospheric pressure chemical ionization source operated in negative mode were used for mass spectrometric detection. Data acquisition was carried out in multiple reaction monitoring mode. Recoveries were predominately within 65 . 2%-118 . 0%. Method quantification limits were 0 . 1-9 . 7 ng/g dw ( dry weight ) . This method was successfully applied to the analysis of the target endocrine disrupting chemicals in carps collected from the Pearl River. with the exception of carbanilide and triclocarban, the rest analytes were detected in fish tissue samples, with the concentrations varied within the range of 0. 1-22. 6 ng/g dw.

Expression analysis of vasa in Asian paddle crab (Charybdis japónica) exposed to Bisphenol A

Background: Bisphenol A (BPA) is an endocrine-disrupting chemical (EDC) with a weak estrogen-like activity in fish that is found ubiquitously in aquatic environments. However, there has been little study about BPA on the endocrine disrupting effects of crab. In the present study, cDNA of vasa was cloned and characterized in the Charybdis japonica. Histological structures of testis and expression patterns of vasa gene in the testis of C. japonica after treatment with BPA were investigated. Results: The cDNA of vasa is composed of 3051 bp with a 2166 bp open reading frame encoding 721 AA. The deduced amino acid sequence contained eight conserved domains of the DEAD-box protein family. The tissue distribution showed that vasa mRNA was specifically expressed in ovary and testis. Histologically, the sperm cells were decreased in number and an acellular zone was seen in the testis. The transcript level of vasa gradually increased with a significant difference between the experimental and control groups. After BPA exposure with 0.50 and 1.00 mg/L for 1,3, 6 and 9 d, the expression levels of vasa increased. Conclusion: These findings suggest that BPA can increase the expression level of vasa mRNA and influence the development of the testis in C. japonica.

Relationship of endocrine disruptors (bisphenol A and diethyl phthalate) with premature thelarche in infant girls / 第二军医大学学报

Objective To study the relationship of endocrine disruptors (EDCs) with premature thelarche in the 0-3 years old baby girls. Methods A total of 60 infant girls diagnosed with premature thelarche were selected as the case group in Children’s Hospital Affiliated to Chongqing Medical University between August 2013 and June 2014, and another 60 healthy girls were included into a control group. Their parents were asked to finish questionnaires and each participants underwent B ultrasonic examination. The serum samples were obtained from both groups by professional doctors to examine the levels of estradiol, follicle stimulation hormone, luteinizing hormone, bisphenol A and diethyl phthalate. Results There were no significant differences in the age, FSH or LH levels between the case group and the control group (P=0.745, 0.721 and 0.195, respectively); the level of E2 in the case group was significantly higher than that in the control group (P=0.017); bisphenol A and diethyl phthalate levels in the case group were significantly higher than those in the control group ([272.9±101.3] μg/L vs [21.8±18.4] μg/L, P=0.000; [0.8±0.3] mg/L vs [0.3±0.1] mg/L,P=0.000). There was a positive correlation between the bisphenol A and diethyl phthalate in the case group (r=0.061, P=0.002), but not in the control group(r=0.302,P=0.102). There was no significant correlation between the sex hormone and the two EDCs (bisphenol A or diethyl phthalate) (P>0.05). Conclusion Premature thelarche in the infant girls between 0 and 3 years old is associated with serum estrogen level, bisphenol A and ethyl phthalate levels, and there is no relationship between genetic factors and environmental factors.

Comparison of growth and pubertal progression in wild type female rats with different bedding types

PURPOSE: Endocrine-disrupting chemicals interfere with the endocrine system and therefore affect growth and pubertal progression. The study aim was to compare the growth and pubertal progression in wild-type female rats with different bedding types. METHODS: Twenty 5-week-old female wild-type Sprague Dawley rats were randomly assigned to two groups with different bedding types: one group received wood shaving bedding, while a second group received corncob bedding. We determined crown-rump length and body weight as anthropometric measurements and assessed the serum growth hormone (GH) and estradiol levels. The gh1 mRNA expression levels were compared using quantitative real time transcription polymerase chain reaction. The estrous cycle was evaluated by vaginal smear. RESULTS: The anthropometric measurements were not significantly different between the two groups. The mean relative expression of the gh1 gene was lower in the corncob bedding group than that in the wood shaving group (P=0.768). Meanwhile serum GH and estradiol were increased in the wood shaving bedding group; however this difference was not statistically significant. The time to first estrus and the length of the estrous cycle were increased in the corncob bedding group; the proportion of normal estrous cycles was also decreased. These findings indicate irregularities in the estrous cycle. CONCLUSION: Endocrine-disrupting chemicals in corncob bedding might be associated with time to first estrus and length of the estrous cycle. Therefore, the type of bedding should be considered as a factor affecting pubertal progression in rodents.