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Leaching of bisphenol A (BPA) from polycarbonate plastic to water containing amino acids and its degradation by radical oxygen species
Abstract
In this study, (1) the change in the concentration of bisphenol A (BPA) leached from polycarbonate plastic (PCP) tube to water samples containing phosphate, sodium barbital, glycine, methionine or albumin at 37 degrees C as a function of time, and (2) the degradation rate of BPA leached from PCP tube to amino acid solutions in the presence of radical oxygen species (ROS) were investigated. The BPA leaching velocity (BPA-LV) from PCP tube to 50 mM glycine at pH 6 or 7 was twice that to control water, and the leaching was enhanced above pH 8. At pH 11, BPA-LV was significantly higher in 50 mM glycine and methionine solutions than in 50 mM NaOH. These results indicate that basic pH and amino acids contained in water could accelerate BPA leaching. The BPA-LV in phosphate buffer was different from the BPA-LVs in other buffers (barbital and glycine) at the same pH. BPA leached to the glycine or methionine solutions at pH 11 was degraded time dependently in a similar manner as the control water in the presence of ROS. The degradation of leached BPA was inhibited in the glycine solution, but was accelerated in the methionine solution. However, degradation of BPA added to freshly prepared methionine was inhibited in a similar manner to BPA in glycine. BPA degradation could be influenced by some kinds of amino acids, but glycine and methionine might be involved in BPA degradation in different ways.
... Matrices in which BPA was analyzed were canned food and beverages, milk, honey, polycarbonate plastics, paper, urine, human breast milk, blood, blood serum, sewage sludge, sea and river water, sediment, and drinking water. [12][13][14][15][16][17][18][19][20][21][22][23] Reversed-phase liquid chromatography was the most frequently used separation technique with acetonitrile/water or methanol/water mobile phases. UV absorption was a widely used detection technique [6,12,14] followed by more sensitive and selective fluorescence detection, [18,22] electrochemical detection, [13,19] and tandem mass spectrometry. ...
... [12][13][14][15][16][17][18][19][20][21][22][23] Reversed-phase liquid chromatography was the most frequently used separation technique with acetonitrile/water or methanol/water mobile phases. UV absorption was a widely used detection technique [6,12,14] followed by more sensitive and selective fluorescence detection, [18,22] electrochemical detection, [13,19] and tandem mass spectrometry. [20,21] Due to the variety of samples, a broad range of sample preparation techniques was used. ...
... [21,22] Many analytical procedures included solid-phase extraction on nonpolar, ion-exchange or mixed-mode stationary phases depending whether the purpose was concentration of analyte or removal of the interferences. [12][13][14][15][16][17]19,21,22] In some cases, samples were derivatized to improve the sensitivity: for example samples of ready-made meals with pyridine-3sulphonyl chloride to enable more sensitive positive ionization in tandem mass spectrometry (MS/MS) detection. [21] Benzophenone (BFN), another pseudoestrogenic compound frequently used as a UV screen in various products, can be an ingredient in UV-curing thermochromic inks as well. ...
The endocrine disruptors bisphenol A (BPA) and benzophenone (BFN) could be important ingredients in thermochromic printing inks in significant amounts. Due to patent protection and use of the inks, manufacturers are not obliged to state their precise chemical composition. These substances in increasingly used thermochromic printing inks present a hazard for human health and environment in the case of inappropriate application and waste disposal. In this work we enabled identification of the inks that contain these hazardous substances by developing a new method for the analysis of BPA and BFN in thermochromic printing inks. The method is based on the reversed-phase liquid chromatography (LC) with UV detection at 226 and 254 nm. Ultrasound-assisted sample extraction in methanol was proven to be the most suitable and effective among several other solvents. The method was completely validated with satisfactory results. The specificity of the method was proven by the additional LC–tandem mass spectrometry analysis. A representative group of 15 ink samples from various manufacturers, curing and printing modes was analyzed. BPA was found in three samples with mass fractions of about 2% while BFN was found in two samples with mass fractions of 0.34 and 0.66%.
... The leaching of BPA from materials can occur [7], leading to its release into the environment, which is considered to be the source of contamination [8]. Due to its constant release and leakage from the plastic products, this hazardous molecule has "pseudo-persistent" characteristics in spite of being biodegradable in the environment [3,6]. ...
... The accumulation of plastic waste in the marine environment is worrying as studies have shown that BPA from plastic leaks faster [7,14], while its bacterial degradation is much slower [15] in marine than in freshwater systems. ...
Over the last decade, bisphenol A (BPA) has become a chemical of concern in the marine environment. There is little data on BPA levels in the eastern Adriatic Sea, Croatian waters. This study provides concentrations of BPA in marine sediments and suspended matter sampled from the Kaštela Bay (the central part of the Adriatic Sea) for two years. The results obtained show that BPA in sediment samples ranged from 1.05 to 46.31 µg kg-1, while they were higher in the suspended matter, ranging from 1.84 to 81.39 µg kg-1. To demonstrate a possible correlation between BPA concentrations and other parameters in sediment and suspended matter, the granulometric composition and organic matter content were determined. There was no correlation between BPA and investigated sediment characteristics. To assess the possible effects of BPA on marine biota, its possible estrogenic effect was also investigated by calculating estradiol equivalent concentration (EEQ, µg kg-1), the maximum value of which, in this study, was 0.0181 µg kg-1 in the sediment samples and 0.0317 µg kg-1 in suspended matter samples. Based on the presented results, it is unlikely that BPA could cause significant endocrine disruption to marine life in the study area.
... BPA is an endocrine-disrupting chemical which is continuously released into the environment because of its extensive usage as plasticizer and other industrial applications. BPA radical, are formed by a reaction of radical oxygen [37][38]. ...
Bisphenol A (BPA) is an organic compound with the chemical formula C15H16O2 and is made from phenol and acetone. It is a colorless solid that is soluble in organic solvents, but poorly soluble in water, having two phenol functional groups, it is used to make polycarbonate polymers and epoxy resins, along with other materials used to make plastics. Polycarbonate plastic is made by reacting BPA with phosgene. The mitochondrial toxicity was estimated by the assay of mitochondrial marker enzymes, by measuring the level of lipid peroxidation, GSH levels and levels of other antioxidant enzymes such as GPx, GR and SOD. Respiratory function of testicular mitochondria appears particularly susceptible to xenobiotic actions, which can contribute to a decrease in mitochondrial produced ATP and even to predispose cells to undergo mitochondria-mediated cell death. Our study showed that exposure to BPA induces significant oxidative stress in testicular mitochondria in mice and melatonin scavenges the free radicals. Human exposure to BPA is due to its widespread use, along with reproductive and developmental effects reported in animal study have generated considerable attention on this chemical in recent years. These aspects need further investigation in properly conducted studies with a wide dose range of BPA. Keywords: Bisphenol A, Lipid Peroxidation, Antioxidant enzymes and EDCs.
... It has been suggested that the polycarbonate polymer can be degraded by the amines leading to the BPA release [51]. A release of 0.01 mg/L of BPA was observed in glycine and methionine solutions (pH 11) stored in polycarbonate plastic tubes at 37 °C for 30 min [52]. In another study, the polycarbonate bottles were immersed in amine and amide solutions and incubated at 120 °C for 1 h. ...
Additives, such as bisphenol A (BPA) that are added to packaging material to enhance functionality may migrate into food products creating a concern for food safety. BPA has been linked to various chronic diseases, such as: diabetes, obesity, prostate cancer, impaired thyroid function, and several other metabolic disorders. To safeguard consumers, BPA migration limits have been defined by regulatory bodies. However, it is important to address the underlying factors and mechanisms so that they can be optimized in order to minimize BPA migration. In this review, we determine the relative importance of the factors, i.e. temperature, contact time, pH, food composition, storage time and temperature, package type, cleaning, and aging, and packaging damage that promote BPA migration in foods. Packaging material seems to be the key source of BPA and the temperature (applied during food production, storage, can sterilization and cleaning processes) was the critical driver influencing BPA migration.
... Due to the elevated temperature and static pressure from compacted waste items in the landfill, polycarbonates and epoxy resins degrade to the constituent monomer BPA (Kwan & Takada, 2016). Furthermore, the BPA polymer easily dissociates into a BPA monomer under alkaline conditions, accelerating BPA leaching from polycarbonate plastics above pH 8 (pKa of BPA varies between 9.6 and 10.2) (Aldwaish et al., 2022;Sajiki & Yonekubo, 2004). Due to its hydrophilic nature, BPA is sequestered from its polymer matrix and can be found in the porewater of open dumpsite . ...
Bisphenol A (BPA) is an anthropogenic chemical compound utilized to manufacture a wide range of consumer products, such as polycarbonate, polyvinyl chloride (PVC), food packages, and thermal papers. Because of its extensive worldwide use, BPA is pervasive in the environment, negatively affecting aquatic life. Therefore, we studied the occurrence, persistence, and ecological risk of BPA in surface water receiving raw leachate from a municipal solid waste (MSW) open dump in Kerawalapitiya, Sri Lanka. Our findings corroborate that the BPA average concentrations in the canal network were 0.4–42.6 µg/L during the wet season and 0.2–4.9 µg/L during the dry season. The levels of BPA at 11 locations (out of 16) during both seasons differed significantly from the upstream sample, where there was no impact from the dump site ( p < 0.05), indicating the ubiquitous occurrence and persistence of BPA in the canal network. BPA levels in the waterbodies are greater in the wet period than in the dry period because of the continuous ingress of run‐off‐driven leachate to the canal network. Our study infers that pH and salinity correlate positively with BPA, while temperature, DO, and TSS are negatively correlated with BPA. BPA levels in five locations during the wet season and one during the dry season surpassed the tolerable level of BPA stipulated by the Canadian Federal Environmental Quality Guidelines to safeguard aquatic life, which is 3.5 µg/L. The findings of the acute ecological risk assessment articulate that during the wet season, Mozambique tilapia ( Oreochromis mossambicus ) and orange chromide ( Etroplus maculatus ) constitute a high acute risk, while they pose a medium acute risk during the dry season. Our study suggests that the relevant authorities must prevent the ingress of runoff rich with BPA onto the canal network to protect aquatic life.
... Studies have indicated that food and drinks stored in such containers can contain trace amount of BPA, a synthetic chemical that interferes with the body's natural hormonal messaging system. The same studies found that repeated re-use of such bottles, which get dinged up through normal wear and tear and while being washed, increases the chance that chemicals will leak out of the tiny cracks and crevices that develop over time (Groff 2010;Huang et al. 2011;Lang et al. 2008;Lee et al. 2008;Oehlmann et al. 2008;Rubin et al. 2001;Sajiki 2001;Sajiki and Yonekubo 2004;Vandenberg et al. 2007;Woodruff et al. 2010). Other studies also indicated that a toxic chemical, phthalates, also leaches from plastic material containers which affects living organisms (Al-Saleh et al. 2011;Chen et al. 2008;Heudorf et al. 2007; Martino-Andrade and Chahoud 2010; Montuori et al. 2008;Sajiki and Yonekubo 2003;Schettler 2006;Wagner and Oehlmann 2009;2011). ...
... Biotransformation by microbes can generate beneficial compounds, whereas biodegradation eliminates hazardous chemicals. Bisphenol A (BPA) is a significant organic compound that is widely employed in the production of polycarbonate goods, including epoxy resins, phenolic resins, and other specialty products (Sajiki and Yonekubo, 2004). Global usage has led to the pervasive presence of BPA in the environment. ...
Pantoea dispersa is a Gram-negative bacterium that exists in a variety of environments and has potential in many commercial and agricultural applications, such as biotechnology, environmental protection, soil bioremediation, and plant growth stimulation. However, P. dispersa is also a harmful pathogen to both humans and plants. This "double-edged sword" phenomenon is not uncommon in nature. To ensure survival, microorganisms respond to both environmental and biological stimuli, which could be beneficial or detrimental to other species. Therefore, to harness the full potential of P. dispersa, while minimizing potential harm, it is imperative to unravel its genetic makeup, understand its ecological interactions and underlying mechanisms. This review aims to provide a comprehensive and up-to-date overview of the genetic and biological characteristics of P. dispersa, in addition to potential impacts on plants and humans, as well as to provide insights into potential applications.
... It has been reported that BPA could increase the level of ROS and cause oxidative stress in fish [43,44]. Oxidative stress brings a variety of hazards, and it is necessary to remove excess ROS by increasing the activity of antioxidant enzymes in the body [45]. ...
The fatty liver is one of the main problems in aquaculture. In addition to the nutritional factors, endocrine disrupter chemicals (EDCs) are one of the causes of fatty liver in fish. Bisphenol A (BPA) is a plasticizer widely used in the production of various plastic products and exhibits certain endocrine estrogen effects. Our previous study found that BPA could increase the accumulation of triglyceride (TG) in fish liver by disturbing the expression of lipid metabolism-related genes. How to recover the lipid metabolism disorder caused by BPA and other environmental estrogens remains to be explored. In the present study, Gobiocypris rarus was used as a research model, and 0.01% resveratrol, 0.05% bile acid, 0.01% allicin, 0.1% betaine, and 0.01% inositol were added to the feed of the G. rarus that exposed to 15 μg/L BPA. At the same time, a BPA exposure group without feed additives (BPA group) and a blank group with neither BPA exposure nor feed additives (Con group) were setted. The liver morphology, hepatosomatic index (HSI), hepatic lipid deposition, TG level, and expression of lipid metabolism-related genes were analyzed after 5 weeks of feeding. The HSI in bile acid and allicin groups was significantly lower than that in Con group. The TG in resveratrol, bile acid, allicin, and inositol groups returned to Con level. Principal component analysis of TG synthesis, decomposition, and transport related genes showed that dietary bile acid and inositol supplementation had the best effect on the recovery of BPA-induced lipid metabolism disorder, followed by allicin and resveratrol. In terms of lipid metabolism-related enzyme activity, bile acid and inositol were the most effective in recovering BPA-induced lipid metabolism disorders. The addition of these additives had a restorative effect on the antioxidant capacity of G. rarus livers, but bile acids and inositol were relatively the most effective. The results of the present study demonstrated that under the present dosage, bile acids and inositol had the best improvement effect on the fatty liver of G. rarus caused by BPA. The present study will provide important reference for solving the problem of fatty liver caused by environmental estrogen in aquaculture.
... Dropping of pH also initiates leaching of BPA from dental resin composite and adhesives. [28][29][30] For Modern dental filling material, average amount for one filling (approximately 0.25 g) contains less than 0.5 µg of BPA comparing to traditional filling material which contains 5 µg BPA. After being used for 1 year, accumulated BPA release was still less than EFSA and US EPA standard for one day. ...
Bisphenol-A(BPA) and Dioxins pose a serious threat to human health. Estrogenicity is the main effect to human being caused by BPA overdose. In addition, Dioxins are ones of the most hazardous chemicals to the systemic health. This review gathered the detail information of these two toxic products in terms of chemical formulas and hazard to human general and oral health. Orthodontic aspect of these two chemicals is intriguing and included. While BPA releases from orthodontic material, Dioxins may cause dental defect especially permanent molar and incisor [Molar-incisor hypomineralization (MIH)]. Although the amount of BPA released from orthodontic material is well below the standard, recommendations for orthodontist of how to minimize this BPA release were given. The suggested role of orthodontist to manage the Dioxins toxicity to the dental health in the community was also versed.
... In addition to WWTP effluent and rainfall runoff, microplastics may be potential sources for BPs in surface water due to the release of monomers during the aging process. Numerous studies have shown that BPA will be available for leaching from microplastics in seawater and surface water (Notardonato et al. 2019;Sajiki and Yonekubo 2004;Xu et al., 2020) Meanwhile, some available studies have investigated the presence of microplastics in surface water in China, including Yongjiang River, Pearl River, Hanjiang River, and Yangtze River Lin et al. 2018;Wang et al. 2017), with the abundance ranges of 379-8920 items/m 3 . Thus, microplastics may contribute to BPs in surface water, although more knowledge is needed to verify the hypothesis. ...
Bisphenol analogues (BPs) including bisphenol a (BPA) have been broadly utilized as industrial feedstocks and unavoidably discharged into water bodies. However, there is little published data on the occurrence, distribution, and environmental risks of other BPs in surface water. In this study, ten BPs besides BPA were analyzed in surface water from the Pearl River, South China. Among these detected BPs, BPA, bisphenol F (BPF), bisphenol AF (BPAF), and bisphenol S (BPS) were the most frequently detected compounds. The median concentrations of the measured BPs were ranked in the order of BPA (34.9 ng/L) > BPS (24.8 ng/L) > BPAF (10.1 ng/L) > bisphenol F (BPF) (9.0 ng/L) > bisphenol B (BPB) (7.6 ng/L) > bisphenol C (BPC) (1.2 ng/L). Among them, BPA and BPS were predominant BPs, contributing 68% of the total ten BPs in surface water of the Pearl River. These results demonstrated that BPA and BPS were the most extensively utilized and manufactured BPs in this region. The source analysis of BPs suggested that the BPs may be originated from domestic wastewater, wastewater treatment plant (WWTP) effluent, and the leaching of microplastic in surface water of the Pearl River. The calculated BP-derived estrogenic activity exhibited low to medium risks in surface water, but their combined estrogenic effects with other endocrine disrupting compounds should not be ignored.
... With the rapid development of science and society, the treatment of environmental pollution, particularly water pollution, has received increasing attention. Recently, the contamination of water resources has been severe, particularly with the increasing production and consumption of organic chemicals such as plastics, dyes, herbicides, and pharmaceutical/endocrine-disrupting chemicals (EDCs) (Sajiki and Yonekubo, 2004;Menting et al., 2019). Bisphenol-A (BPA), chemically called 4, 4 ′ -dihydroxy-2, 2-diphenyl propane, has a polar organic structure and consists of two symmetrical benzene rings; it is also a well-known endocrine-disrupting compound. ...
The advanced oxidation process (AOP) through ultrasound-assisted photocatalytic degradation has attracted much attention in removing emerging contaminants. Herein, CoFe2O4-GO and CoFe2O4-g-C3N4 nanocomposites were synthesized using the ultrasound-assisted co-precipitation method. TEM, XRD, XPS, EDS, SEM, and FT-IR techniques characterized the structural, morphological, and chemical properties of the synthesized nanocomposites. The analyses showed that CoFe2O4 structure was nano-sized and distributed more homogeneously in graphene oxide (GO) layers with oxygenated functional groups than graphitic carbon nitride (g-C3N4). While the efficiency of composite catalysts, as photocatalysts, for degradation of bisphenol-A (BPA) was low in the visible region in the presence of persulfate, their catalytic efficacy was higher with sonolytic activation. The addition of persulfate as an oxidant remarkably enhanced the target pollutant degradation and TOC removal of BPA solution. Both composite catalysts showed 100 % BPA removal with the synergistic effect of visible region photocatalytic oxidation and sonocatalytic oxidation in the presence of persulfate at pH 6.8. In ultrasound-assisted photocatalytic oxidation of BPA, the highest mineralization efficiencies were obtained at 2 h treatment time, pH 6.8, 16 mM PS, catalyst dosages of 0.1 g/L CoFe2O4-GO, and 0.4 g/L CoFe2O4-g-C3N4 as 62 % and 55 %, respectively. An effective catalyst was obtained by reducing e⁻/h⁺ recombination and charge transfer resistance by decorating the GO layers with CoFe2O4.
... Bisphenol A is not an isolated chemical that leaches out from plastics. Bisphenols are a group of related chemicals that leaches out from the plastics [10][11][12]. We can take the example of Bisphenol B. ...
... Nonetheless, since the 1950's, BPA has been produced in large quantities, due to many factors such as its cost-efficient method of producing products, including plastic bottles, food containers, thermal receipts, and dental sealants [6]. Early research demonstrated that BPA had low toxicity and was rapidly metabolized, ultimately leading to safety approval of use in plastic production [11]. It was later found in both in vivo and in vitro studies that BPA acts as an endocrine disruptor, leading to adverse endocrine effects such as increased prostate weight, growth of mammary glands, and altered postnatal development; therefore, challenging previous beliefs that BPA was safe at low doses [12]. ...
Bisphenol A (BPA) and bisphenol S (BPS) are environmental contaminants that have been associated with the development of insulin resistance and type 2 diabetes (T2D). Two organs that are often implicated in the development of insulin resistance are the skeletal muscle and the adipose tissue, however, seldom studies have investigated the effects of bisphenols on their metabolism. In this review we discuss metabolic perturbations that occur in both the skeletal muscle and adipose tissue affected with insulin resistance, and how exposure to BPA or BPS has been linked to these changes. Furthermore, we highlight the possible effects of BPA on the cross-talk between the skeletal muscle and adipose tissue.
... MPs are undoubtedly considered as sources of chemical contaminants, owing to the release of monomers and oligomers in the aging process ( Chen et al., 2019a ;Guo et al., 2020 ;Liu et al., 2020a ;Liu et al., 2019b ). Evidence from numerous studies has reported that bisphenol A (BPA), the monomer of PC plastics, which is one of the prevailing endocrine disrupting compounds (EDCs), will be leached out from PC in seawater and freshwater environments ( Notardonato et al., 2019 ;Sajiki and Yonekubo, 2004 ;Xu et al., 2019 ). Despite that BPA is prohibited to be added into PC baby bottles and other food containers ( Erickson, 2011 ), diverse PC applications still utilize BPA as raw material. ...
Bisphenol A polycarbonate (BPA PC) is a kind of widely used engineering plastics. However, excessive usage causes the production of plastic wastes, following property changes of polymers and high risks of released chemicals during outdoor weathering. In this study, we systematically investigated the pho- toaging behavior of PC microplastics (MPs) in aquatic environment and evaluated the potential risk of released intermediates. Light irradiation along with mechanical abrasion facilitated the fragmentation of PC MPs and stimulated photooxidative modification during 640 h of ultraviolet (UV) exposure. Continu- ous degradation of the polymer was accompanied with dramatic decline of molecular weight. Also, BPA was released from irradiated PC MPs with a trend of an initial rapid increase followed by a decrease ver- sus the irradiation time, and the maximum concentration of dropped BPA was detected up to 652.80 ±72.89 μg/g (43.39% and 56.61% respectively in particles and leachates). However, the releasing amount of BPA in the leachate merely occupied 2.7% of the total organic carbon (TOC) leached out, suggesting that a great number of unknown organic products were produced other than BPA. Liquid chromatography- time-of-flight-mass spectrometry (LC-TOF-MS) analysis showed that these organic compounds forming MPs-derived dissolved organic matter (MPs DOM) were partly composed of 4,4’-dihydroxybenzophenone (DHB), p-hydroxybenzoic acid (p-HBA) and methyparaben (MeP), which would also contribute to the es- trogenic activity. The degradation pathway of PC MPs was elaborated with the photolysis process of PC dimer and BPA, and the remarkable photoaging of PC MPs was mainly dominated by the generated reac- tive oxygen species (ROS). The findings of this study indicated that understanding the photoaging process of PC MPs was vital to evaluate their integral cumulative estrogenic activity in aquatic environment, and further highlighted the notable possible risks of plastic leachates to exposed biota.
... BPA is a synthetic estrogen agonist used in manufacturing everyday products. It can be detected in animals and humans in almost every system, organ, tissue, and cell, and is linked to destructive consequences in female fertility, such as diseases and cancers [2][3][4]. BPA has been linked to increased primordial follicle recruitment, a decrease in the number of viable oocytes and decreased antral follicular growth (reviewed in [5]). Our group has reported poor oocyte and embryo quality with lower cleavage and blastocyst rates as well as alterations in chromosome alignment, sex ratios, spindle formation, apoptosis levels, and gene expression in response to BPA treatment of in vitro produced bovine oocytes [3,6]. ...
Bisphenol A (BPA) and its alternative, bisphenol S (BPS), are widespread endocrine disrupting compounds linked in several studies to poor female fertility. Sufficient oocyte competence and subsequent embryo development are highly dependent on oocyte maturation, an intricate process that is vulnerable to BPA. These effects as well as the effects of its analog, BPS, have not been fully elucidated. Although the harmful consequences of bisphenols on the reproductive system are largely due to interferences with canonical gene expression, more recent evidence implicates noncoding RNAs, including microRNAs (miRNA), as significant contributors. The aim of this work was to test the hypothesis that abnormal expression of key miRNAs during oocyte maturation and embryo development occurs following BPA and BPS exposure during maturation. Using qPCR, primary and mature forms of miR-21, -155, -34c, -29a, -10b, -146a were quantified in an in vitro bovine model of matured cumulus-oocyte complexes, fertilized embryos, and cultured cumulus cells after exposure to BPA or BPS at the LOAEL dose (0.05 mg/mL). Expression of miR-21, miR -155, and miR-29a were markedly increased (P = 0.02, 0.04, <0.0001) while miR-34c and miR-10b were decreased (P = 0.01, 0.01), after BPA treatment. miR-146a expression remained stable. BPS had no effects, suggesting may not exert its actions through these six miRNAs examined. Overall, this study indicates that BPA effects are likely miRNA specific rather than a global effect on miRNA synthesis and processing mechanisms and that its analog, BPS, may not possess the same properties required to interfere with these miRNAs during bovine oocyte maturation.
... Ayrıca alkali ortamlarda özellikle yüksek sıcaklıkta hidroliz olayı daha hızlı gerçekleşmektedir. Bazı çalışmalarda alkali ortamlarda yüksek sıcaklıktaki suyla temas halinde olduğunda PC malzemenin hidrolitik depolimerizasyonunun arttığı ve buna bağlı olarak da BPA migrasyon değerlerinin yüksek olduğu gösterilmiştir [44,48,66,[70][71][72][73]. PC malzemelerde kullanım durumunun, polimerin degradasyonununda UV ışıktan bile daha etkili olduğu ve çok fazla kullanılmış olan PC malzemelerin kullanılmaması gerektiği de belirtilmektedir [73.] ...
Polikarbonat (PC) malzeme, gıda ile temas eden malzemelerden özellikle su damacanaları ve sofra malzemelerinin üretiminde yaygın şekilde kullanılmaktadır. Bisfenol-A (BPA) ise PC malzemelerin üretiminde kullanılan önemli bir monomerdir ve son yıllarda BPA’nın PC malzemelerden gıdaya geçebildiği ve insan sağlığı üzerinde olumsuz etkilerinin olabileceği doğrulanmıştır. PC malzeme farklı sıcaklıklarda farklı sürelerde su ile temas halinde bulunabilmekte, yıkama, sterilizasyon gibi tekrarlayan işlemlere maruz kalabilmektedir. Nem, yüksek sıcaklık gibi farklı çevresel koşullara maruz kaldığında PC malzemenin degrade olabileceği ve PC malzemenin degradasyona uğraması sonucunda malzemede bulunan BPA miktarında değişiklik olabileceği bazı çalışmalarda gösterilmiştir. Bu nedenle bu çalışmada su ile temas halinde kullanılan PC malzemelerde BPA migrasyon mekanizması incelenmiş, PC malzemenin maruz kaldığı sıcaklık, süre ve tekrarlayan işlemlerin BPA migrasyonuna etkisi araştırılmıştır.
... Our results are consistent with those from a previous study, where human intakes of BPA were 1−2 orders of magnitudes lower than the intakes estimated from the WBE. 45 This shows that urinary excretion is not a major source for the BPA and BPS in wastewater in South East Queensland, and other sources such as direct leaching from plastic products 57 and industrial input 58 are likely the primary sources of bisphenols that reach WWTPs. Lopardo et al. 28 focused on estimating population wide total daily intake of BPA from free BPA and BPA sulphate in the wastewater. ...
Health concerns and related regulation of bisphenol A (BPA) in some countries have led to an increase in the production and use of unregulated and poorly understood BPA analogues, including bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), and bisphenol AF (BPAF). To assess the temporal trends of human exposure to BPA analogues, urine and wastewater samples were collected from South East Queensland, Australia between 2012 and 2017 and analyzed for five bisphenols using validated isotope dilution liquid chromatography tandem mass spectrometry methods. BPA and BPS were the predominant bisphenols detected in both urine and wastewater samples, with median concentrations of 2.5 and 0.64 μg/L in urine and 0.94 and 1.1 μg/L in wastewater, respectively. BPB, BPF, and BPAF had low detection frequencies in both urine and wastewater samples. Concentrations of BPA in both urine and wastewater decreased over the sampling period, whereas concentrations of BPS increased, suggesting that BPS has become a BPA replacement. The contributions of urinary excretion to wastewater were calculated by the ratio of daily per capita urinary excretion to wastewater-based mass loads of bisphenols. Urinary BPA and BPS contributed to less than 1% of the load found in wastewater, indicating that much of the BPA and BPS originates from other sources.
... Besides BPA and phosgene, there is another type of compound that goes into the building of the polycarbonate chain called chain terminator. Chain terminator is added to cap the ends of the chains, limiting how long they can grow (Sajiki and Yonekubo, 2004). ...
BPA is an EDC which is continuously released into the environment because of its extensive usage as plasticizer and other industrial applications. The present study establishes BPA induced alterations in mitochondrial marker enzymes and hence cause mitochondrial dysfunction. Studies were performed to evaluate the histopathological changes in tissue on exposure to different doses of BPA for different time periods. Light microscopic examination of samples was done to evaluate the possible changes caused by treatment of different doses of BPA. After getting the results in light microscopy the changes and damage caused by BPA ultra-structurally were observed. Light microscopic study showed that BPA exposure for short duration of 7 days did not resulted in significant change in histology of Rat of treated animals. Light microscopic observations showed that low doses of BPA (5 and 10 mg/kg body weight) exposure for 14 days caused reduction in the number of cells in the layers of seminiferous tubules. Highest dose of BPA treatment for 14 days caused much damage to the seminiferous tubules. There were many ultra-structural changes found in the treated groups as compared to the control group. Hence it can be stated that due to the toxic effect of BPA the mitochondrial marker enzymes have shown marked reduction in their activities. Keywords: BPA, EDCs, Light microscopic, Mitochondria and Toxicity.
... What attract attention are especially marine plastic litter on the global scale presently and harm to marine animals. We should also recognize that plastic additives, such as bisphenols, phthalates, and phosphate flame retardants, have endocrine-disrupting properties as discussed in detail in previous chapters and are released from products [66]. ...
The Minamata Convention was established following the Minamata disaster. To protect humans and the environment from persistent organic pollutants, the Stockholm Convention was established. However, there are many remaining chemicals with potential hazardous properties so that we must speed up and shorten the time to take action for such chemicals. Emerging environmental hazards including toxic chemicals are a threat to child health. A considerable number of birth cohorts have been recently established, and evidence reveals that there are certain adverse associations between environmental chemical exposures in utero and adolescent and children’s health. However, there are remaining agenda in preventing exposure of children to hazardous chemicals. We have pointed out challenges in future studies on (1) other risk factors that are not comprehensively addressed in this book, (2) mixture exposure, (3) genetics, (4) biomolecular approaches, (5) birth cohorts and consortiums, and (6) inclusion of environment into the original Developmental Origins of Health and Disease concept, as well as (7) long-term follow-up. The United Nations set the sustainable development goals. We should act together to create cleaner and safer environments for children by preventing exposure to chemical hazards, which will contribute to a healthier, more secure, and sustainable future for the world.
... One example is bisphenol-A, an estrogen disrupter that affects invertebrate and vertebrate development and reproduction (reviewed by Rubin 38 ), and previously shown to be released from plastic tanks made of polycarbonate or polysulfone. 39,40 If reused, plastic components of the housing system could also leach out some chemicals that became adsorbed onto their surface in previous experiments. Although this has not been yet reported in the literature, plastic polymers used in commercial housing systems may also release micrometric plastic particles that could interfere with the experiments. ...
Many anthropogenic chemicals and plastic debris end up in the aquatic ecosystem worldwide, representing a major concern for the environment and human health. Small teleosts, such as zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes), offer significant advantages over classical animal models and are currently used as first-line organisms to assess environmental risks associated with many aquatic toxicants. Toxicological studies require the use of inert materials and controlled conditions. Yet, none of the available commercialized systems is adequate to assess the toxic effect of microplastics, because they contain components made of plastic polymers that may release micrometric plastic particles, leach manufacturing compounds, or adsorb chemicals. The ZEB316 stand-alone housing system presented in this study is meant to be a cost-effective and easy-to-built solution to perform state-of-the-art toxicological studies. It is built with inert and corrosion-resistant materials and provides good housing conditions through efficient recirculation and filtration systems. Assessment of water parameters and fish growth performance showed that the ZEB316 provides housing conditions comparable to those available from commercial housing systems.
... BPA (Fig. S1), an endocrine disrupting compound (EDCs), is widely used for making plastic products such as water bottles. Under acidic or basic conditions, the BPA is easily leached out from BPA-based products when its ester bonds linkage are hydrolyzed [1]. Due to their wide use, human exposure to the BPA is unavoidable. ...
... (Yehye et al., 2015) BPA is a monomer for polycarbonate and is known to leach from this material. (Sajiki and Yonekubo, 2004). DEHP was the most common plasticizer for polyvinyl chloride (PVC) but it is banned for consumer products and rarely found today as an extractables in (Bui et al., 2016) In addition, it is still used in medical products such as sampling bags for donor blood and storage of blood products. ...
This article demonstrates, on a quantitative level, that leachables - potentially accumulated during a biopharmaceutical manufacturing process - will be significantly reduced/removed during four key downstream process steps: cell harvest using centrifugation or depth filtration, sterile filtration and virus filtration. Eight common leachables model compounds (LMCs) were spiked into typical feed solutions containing buffer and proteins and were analyzed post-processing in the supernatant or filtrates by HPLC-UV. The clearance rates were calculated as the quotient between the scavenged and initially spiked amount of each leachable. High clearance rates were found for hydrophobic LMCs for all investigated downstream operation steps. It is shown that the removal of cells and cell debris from a culture broth reduces the amount of LMCs almost completely after centrifugation or depth filtration. Also, sterilizing-grade and virus filtration provided a high scavenger effect to most of the LMCs. In contrast, only one hydrophilic acid was not significantly scavenged by the described operations. The possibility to include leachables sinks to a process qualification and risk mitigation concept is explained.
... Aminolysis of polycarbonate can occur with 50 mM solutions of methionine and adjusted to pH 11 by sodium hydroxide at lower temperatures of 37°C. [227][228][229] The migration rates range from 0.38 to 0.49 mg/L/day and corrected for the realistic surface to volume ratio of baby bottles of about 8/dm, 0.11-0.14 mg/L/day. ...
... The U.S. Environmental Protection Agency (EPA) has published a reference dose (RfD, 0.05 mg/kg/day) for BPA as the acceptable daily intake (ADI) for BPA through food additive use. Oral gavage was selected as the administration route, as in humans the uptake of BPA takes place mainly from food products [6][7][8][9][10] . BPA application took place from day 1 to 7 of pregnancy, being day 0 defined as the day at which a vaginal plug was registered. ...
Endocrine disrupting chemicals are long suspected to impair reproductive health. Bisphenol A (BPA) has estrogenic activity and therefore the capacity of interfering with endocrine pathways. No studies dissected its short-term effects on pregnancy and possible underlying mechanisms. Here, we studied how BPA exposure around implantation affects pregnancy, particularly concentrating on placentation and uterine remodeling. We exposed pregnant female mice to 50 µg/kg BPA/day or 0.1% ethanol by oral gavage from day 1 to 7 of gestation. High frequency ultrasound was employed to document the presence and size of implantations, placentas and fetuses throughout pregnancy. Blood velocity in the arteria uterina was analyzed by Doppler measurements. The progeny of mothers exposed to BPA was growth-restricted compared to the controls; this was evident in vivo as early as at day 12 as analyzed by ultrasound and confirmed by diminished fetal and placenta weights observed after sacrificing the animals at day 14 of gestation. The remodeling of uterine spiral arteries (SAs) was considerably impaired. We show that short-term exposure to a so-called "safe" BPA dose around implantation has severe consequences. The intrauterine growth restriction observed in more than half of the fetuses from BPA-treated mothers may owe to the direct negative effect of BPA on the remodeling of uterine SAs that limits the blood supply to the fetus. Our work reveals unsuspected short-term effects of BPA on pregnancy and urges to more studies dissecting the mechanisms behind the negative actions of BPA during early pregnancy.
... Because of its cross-linking properties in the manufacture of polycarbonate materials and epoxy resins, this compound has been widely used in the production of plastics since 1957 [5,6]. Therefore, leaching of BPA from polycarbonate plastics, baby bottles, dental sealants, epoxy resin linings for food and beverage containers, water pipes, and thermal papers makes it a ubiquitous contaminant of the environment [7,8]. It can bioaccumulate both in ground water, wastewater, and air leading to continual exposure of humans and animals, whereas for most species food is the major route of exposure [9]. ...
Nowadays, many different chemicals exerting negative effects on both human and animal health are widely present in the environment. Compounds that interfere in the action of endocrine system due to their structural similarities to the real hormones called endocrine disrupting chemicals have received much attention because they are suspected to affect reproduction, development, metabolism of living organisms and even induce cancer. Moreover, the endocrine-related disorders are often passed down to the next generations and alter their disease susceptibility. This group of substances includes both naturally occurring chemicals (e.g., phytoestrogen—coumestrol) and synthetic compounds used in industrial processes, agriculture, and household products (e.g., polychlorinated biphenyls, polybrominated biphenyls, polycyclic aromatic hydrocarbons, some pesticides, components of plastics such as bisphenols and phthalates). Among these compounds there are some groups of chemicals still widely used and therefore constituting an important source of health hazards. The most important man-made endocrine disrupting compounds belong to three groups which met with great interest in last years, i.e., phthalates, bisphenols (mainly bisphenol A), and alkylphenols (used mainly as ethoxylates). Decades of their production and usage led to considerable contamination of the environment. They are found in water, air, soil, both animal and plant food. Therefore, growing number of studies are devoted to their degradation, biodegradation, and removal from the environment. Present studies on the biodegradation of phthalates, bisphenols, and alkylphenol derivatives aim mainly at testing of selected bacterial strains of different lineage including some Bacillus sp., Gordonia sp., Pseudoxanthomonas sp., Sphingomonas sp., and Rhodococcus sp. bacteria as well as other bacterial strains. Tests with fungi like Aspergillus sp. and Polyporus sp. or fungal enzymes like laccases are also carried out. Ultimately, understanding metabolic pathways of diverse species and genes involved in the biodegradation may help in constructing bacterial or fungal strains through usage of genetic engineering for effective removal of selected endocrine disrupting compounds. On the other hand, studies on removal of these contaminants from the environment were also undertaken. Biodegradation in natural waters, including seawater and in soil and sediments was tested to gain information on possibility of their removal from contaminated areas.
... The high pH combined with a high temperature can lead to degradation of PC material. It was also stated bySajiki and Yonekubo (2004) that basic pH provokes the degradation of PC material leading to the increased migration values from the material. ...
... However, it is also important to recognize the significance of the reported contamination of oceans [110][111][112] and sediments. 11,67,113 The presence of polycarbonate in oceans is of special concern because leaching of 1a from polycarbonate occurs more rapidly in sea than in fresh waters, 74,114 1a oxidation by radical oxygen species is slower in seawater than in control water, 71 and marine bacteria strains have been found to degrade 1a much more slowly than freshwater strains. 107,115 Furthermore, 1a has been detected in marine organisms including phytoplankton, zooplankton, mussels, herring, flounder, and cod, and bioamplification between phytoplankton and zooplankton has been documented. ...
Designing technologies that mitigate the low-dose adverse effects of exposures to large-volume everyday-everywhere chemicals such as bisphenol A (BPA, 1a ) requires an understanding of the scope of the exposures and...
... BPA is used in the manufacturing of many products, including polycarbonate and epoxy plastic food packaging material, and it has been shown that BPA leaches from containers into foodstuff (Sajiki and Yonekubo 2004;Vandenberg et al. 2007). Geens et al. (2012) estimated a daily human exposure level of 0:1-5 lg=kg bw=d from dietary and nondietary sources. ...
Background:
Bisphenol A (BPA) is a component of polycarbonate plastics to which humans are regularly exposed at low levels, and an endocrine disruptor with effects on several hormonal systems. Bone is a sensitive hormone target tissue, and we have recently shown that in utero and lactational exposure to 25µg BPA/kg BW/day alters femoral geometry in rat offspring.
Objective:
To investigate bone effects in rat offspring after developmental exposure to a BPA dose in the range of human daily exposure (0.1-1.5µg/kg BW/day) as well as a dose to corroborate previous findings.
Methods:
Pregnant Fischer 344 rats were exposed to BPA via drinking water corresponding to 0.5µg/kg BW/day: [0.5], (n=21) or 50µg/kg BW/day: [50], (n = 16) from gestational day 3.5 until postnatal day 22, while controls were given only vehicle (n = 25). The offspring was sacrificed at 5 weeks of age. Bone effects were analyzed using peripheral quantitative computed tomography (pQCT), the 3-point bending test, plasma markers of bone turnover, and gene expression in cortical bone and bone marrow.
Results:
Compared to controls, male offspring developmentally exposed to BPA had shorter femurs. pQCT analysis revealed effects in the [0.5] group, but not in the [50] group; BPA reduced both trabecular area (-3.9%, p < 0.01) and total cross sectional area (-4.1%, p < 0.01) of femurs in the [0.5] group, whereas no effects were seen on bone density. Conversely, bone length and size were not affected in female offspring. However, the procollagen type I N-terminal propeptide (P1NP), a peptide formed during type 1 collagen synthesis, was increased in plasma (42%: p < 0.01) in female offspring exposed to [0.5] of BPA, although collagen gene expression was not increased in bone. The biomechanical properties of the bones were not altered in either sex. Bone marrow mRNA expression was only affected in male offspring.
Conclusions:
Developmental low-dose exposure to BPA resulted in sex-specific bone effects in rat offspring. A dose approximately eight times lower than the current temporary EFSA human tolerable daily intake of 4µg/kg BW/day, reduced bone length and size in male rat offspring. Long-term studies are needed to clarify whether the increased plasma levels of P1NP in female offspring reflect development of fibrosis.
... BPA is used in the manufacturing of many products, including polycarbonate and epoxy plastic food packaging material, and it has been shown that BPA leaches from containers into foodstuff (Sajiki and Yonekubo 2004;Vandenberg et al. 2007). Geens et al. (2012) estimated a daily human exposure level of 0:1-5 lg=kg bw=d from dietary and nondietary sources. ...
Background:
Bisphenol A (BPA) is an endocrine-disrupting chemical that may contribute to development of obesity and metabolic disorders. Humans are constantly exposed to low concentrations of BPA, and studies support that the developmental period is particularly sensitive.
Objectives:
The aim was to investigate the effects of low-dose developmental BPA exposure on metabolic parameters in male and female Fischer 344 (F344) rat offspring.
Methods:
Pregnant F344 rats were exposed to BPA via their drinking water, corresponding to 0.5 μg/kg BW/d (BPA0.5; n =21) or 50 μg/kg BW/d (BPA50; n =16), from gestational day (GD) 3.5 until postnatal day (PND) 22, and controls were given vehicle ( n =26). Body weight (BW), adipose tissue, liver (weight, histology, and gene expression), heart weight, and lipid profile were investigated in the 5-wk-old offspring.
Results:
Males and females exhibited differential susceptibility to the different doses of BPA. Developmental BPA exposure increased plasma triglyceride levels (0.81±0.10 mmol/L compared with 0.57±0.03 mmol/L, females BPA50 p =0.04; 0.81±0.05 mmol/L compared with 0.61±0.04 mmol/L, males BPA0.5 p =0.005) in F344 rat offspring compared with controls. BPA exposure also increased adipocyte cell density by 122% in inguinal white adipose tissue (iWAT) of female offspring exposed to BPA0.5 compared with controls (68.2±4.4 number of adipocytes/HPF compared with 55.9±1.5 number of adipocytes/HPF; p =0.03) and by 123% in BPA0.5 females compared with BPA50 animals (68.2±4.4 number of adipocytes/high power field (HPF) compared with 55.3±2.9 number of adipocytes/HPF; p =0.04). In iWAT of male offspring, adipocyte cell density was increased by 129% in BPA50-exposed animals compared with BPA0.5-exposed animals (69.9±5.1 number of adipocytes/HPF compared with 54.0±3.4 number of adipocytes/HPF; p =0.03). Furthermore, the expression of genes involved in lipid and adipocyte homeostasis was significantly different between exposed animals and controls depending on the tissue, dose, and sex.
Conclusions:
Developmental exposure to 0.5 μg/kg BW/d of BPA, which is 8-10 times lower than the current preliminary EFSA (European Food Safety Authority) tolerable daily intake (TDI) of 4 μg/kg BW/d and is within the range of environmentally relevant levels, was associated with sex-specific differences in the expression of genes in adipose tissue plasma triglyceride levels in males and adipocyte cell density in females when F344 rat offspring of dams exposed to BPA at 0.5 μg/kg BW/d were compared with the offspring of unexposed controls. https://doi.org/10.1289/EHP505.
... Introduction to high temperatures, acidic or basic solutions, and physical damage can lead to the hydrolysis of plastic polymers into the estrogenic monomer. Breakdown of BPA has been reported in several products including baby bottles, water bottles, polyvinyl chloride (PVC) tubing, and plastic containers (Carwile et al., 2009;Lopez-Cervantes & Paseiro-Losada, 2003;Mountfort, Kelly, Jickells, & Castle, 1997;Nerin, Fernandez, Domeno, & Salafranca, 2003;Sajiki & Yonekubo, 2004). BPA can enter our ecosystems when consumer products are disposed into wastewater systems and landfills. ...
The ubiquitous monomer, bisphenol A (BPA), is an endocrine active compound used in the production of polycarbonate plastics and epoxy resin. Environmental biomonitoring and epidemiology studies report continuous exposure in humans that are associated with different adverse health outcomes. The overall goal of this work was to characterize BPA concentrations, toxicokinetic and toxicodynamic profiles that influence tissue-specific BPA biotransformation via xenobiotic metabolizing enzymes (XME), and BPA dependent changes in biotransformation using healthy 1st-2nd trimester clinical specimens obtained from a fetal biobank.
First, we reported a wide range of BPA concentrations in N=50 fetal liver specimens (total BPA range: below limit of quantification - 96.8 ng/g). Both concentrations and metabolic profiles varied across age with significant reduction in BPA-specific XME gene expression of UGT2B15, SULT1A1, and STS in fetal versus adult livers. Next, we examined matched fetal liver, kidney, and placenta in N=12 subjects and observed significant tissue-dependent differences in BPA concentrations, XME expression profiles, and global DNA methylation. Fetal livers exhibited higher BPA concentrations compared to matched tissues; however, XME expression profiles suggest an increased likelihood of BPA-glucuronide deconjugation and BPA-sulfate conjugation across the fetal compartments. With organ-specific differences in the epigenome, only placental global methylation measurements were associated with BPA. Finally, we investigated BPA???s role in pathway specific biological outcomes and regulation in fetal liver. In particular, we identified 14 different XME candidate genes that were down regulated with higher BPA concentrations.
In summary, results suggest that the 1st-2nd trimester human fetus is exposed to a considerable amount of BPA in utero, especially of the active free BPA form. XME expression profiles reveal an altered capacity for BPA biotransformation in the fetus compared to adults, with distinct metabolic profiles across different tissues. Interestingly, higher BPA concentrations in fetal liver were associated with reduced expression of novel XME candidate genes mediated by epigenetic mechanisms. These findings indicate that environmentally relevant concentrations of BPA, even across a short window of development, result in detectable changes in the host???s toxicological defense system.
Bisphenol-A (BPA), a synthetic compound ubiquitously present in the environment, can act as an endocrine disruptor by binding to both canonical and non-canonical estrogen receptors (ERs). Exposure to BPA has been linked to various cancers, in particular, those arising in hormone-targeted tissues such as the breast. In this study, we evaluated the effect of BPA intake through drinking water on ErbB2/neu-driven cancerogenesis in BALB–neuT mice, transgenic for a mutated ErbB2/neu receptor gene, which reproducibly develop carcinomas in all mammary glands. In this model, BPA accelerated mammary cancerogenesis with an increase in the number of tumors per mouse and a concurrent decrease in tumor-free and overall survival. As assessed by immunohistochemistry, BALB–neuT tumors were ER-negative but expressed high levels of the alternative estrogen receptor GPR30, regardless of BPA exposure. On the other hand, BPA exposure resulted in a marked upregulation of progesterone receptors in preinvasive tumors and of Ki67, CD31, and phosphorylated Akt in invasive tumors. Moreover, based on several infiltration markers of immune cells, BPA favored an immunosuppressive tumor microenvironment. Finally, in vitro cell survival studies performed on a cell line established from a BALB–neuT breast carcinoma confirmed that BPA’s impact on cancer progression can be particularly relevant after chronic, low-dose exposure.
Triple negative breast cancer (TNBC) is a subtype of breast tumor characterized for the absence of estrogen and progesterone receptors expression and low HER2/neu expression. Bisphenol A (BPA) is an endocrine disrupting chemical with estrogenic activity that has been associated with increasing rates of breast cancer. Moreover, BPA is a solid organic synthetic chemical employed in the manufacture of many consumer products, epoxy resins and polycarbonate plastics including baby bottles, containers for food and beverages, and the lining of beverage cans. The G-protein-coupled estrogen receptor (GPER) is activated by endogenous hormones and synthetic ligands, such as BPA. GPER is expressed in TNBC cells and its expression is associated with larger tumor size, metastasis and worse survival prognosis. In breast cancer cells, BPA induces activation of signal transduction pathways that mediates migration and invasion via GPER in human TNBC MDA-MB-231 cells. In this study, we demonstrate that BPA induces an increase of GPER expression and its translocation from cytosol to cytoplasmic membrane, metalloproteinase (MMP)-2 and MMP-9 secretion, migration and invasion in murine TNBC 4T1 cells. In a murine TNBC model "in vivo" using 4T1 cells, BPA induces the formation of mammary tumors with more weight and volume, and an increase in the number of mice with metastasis to lung and nodules in lung compared with tumors and metastasis to lung of untreated Balb/cJ mice. In conclusion, our findings demonstrate that BPA mediates the growth of mammary primary tumors and metastasis to lung in a murine model of breast cancer.
An emerging class of pervasive pollutants, microplastics are being increasingly detected in almost all the environmental matrices. Microplastics are plastic particles having a size of less than 5 mm, either formed from the disintegration of large plastics in the environment due to natural and anthropogenic factors, named as secondary microplastics, or manufactured that way for industrial and commercial uses, namely primary microplastics. They occur in a variety of shapes such as beads, fibres, fragments, foams, etc. in nature. As an emerging pollutant, they are gaining popularity among researchers due to massive abundance and yet to be identified potential impacts on different tiers of the ecosystem. This chapter reviews the occurrence and abundance of microplastics in all the environmental compartments, various detection methods, different sources of generation, and their fate and transport in air, water, and soil. A discussion on current trends of their exposure levels on biota and ecotoxicological effects is also included. Further, the potential of microplastics as the carriers of other organic pollutants and leaching out of toxic chemicals from microplastics are also reviewed.
Environmental contextCarbon nanotubes are added to polymers such as polycarbonate and epoxy to form nanocomposites with enhanced material properties. Environmental factors including temperature, UV light exposure and pH have the potential to degrade these composites and increase the release of toxic polymer-associated chemicals. This study investigates how carbon nanotube loading decreases the release of known endocrine-disrupting compounds, bisphenol A and 4-tert-butylphenol, from polymer nanocomposites under simulated weathering environments. AbstractNanoparticles such as carbon nanotubes are increasingly added to polymer matrices to improve tensile strength and electrical and thermal conductivity, and to reduce gas permeability. During use and after disposal, these plastic nanocomposites (PNCs) are degraded into microplastics by physical and chemical processes including mechanical abrasion, UV light exposure, hydrolysis and oxidation. Such polymers have the potential to enter aquatic environments and release potentially hazardous polymer-associated chemicals and transformation products. This work identifies and quantifies polymer-associated chemicals leached from polymers and nanocomposites during simulated environmental exposure. Epoxy and polycarbonate PNCs containing single-walled carbon nanotube (SWCNT) loadings ranging from 0 to 1 wt-% were exposed to water for 5 days, and the release of the chemicals bisphenol A (BPA) and 4-tert-butylphenol (TBP) was measured. The role of UV exposure, pH, temperature and natural organic matter in regulating chemical release was also investigated. Temperature, pH and UV light were found to be the most significant factors influencing release of TBP and BPA from PNCs. Additionally, increasing carbon nanotube loading in both polycarbonate and epoxy composites was found to decrease the release of these phenolic chemicals. A 0.3% higher SWCNT loading decreased the release of BPA 45±18%, and a 1% SWCNT loading decreased chemical release from epoxy by 48±26% for BPA and 58±8% for TBP. This information provides important data that can be used to help assess the risks posed by SWCNT polymer nanocomposites in aqueous environments, particularly as they age and are transformed.
Increasing wastewater generation rates and micro-pollutant levels in environmental matrices constrain energy-efficient and fast control technologies. In this study, different optical and geometrical photocatalytic reactor (PCR) design have been investigated experimentally using BPA molecule as a model pollutant. N-TiO2, Ni-N-TiO2, Sn-N-TiO2, Ni-Sn-C-N-TiO2 and Fetched-Ni-Sn-C-N-TiO2 nano-layered thin films (TFs) have been produced and employed as immobilized nano-catalysts. An ultrasound-assisted fluorine (F) etching method was applied to Sn and Ni co-doped TFs. The synthesized TFs were characterized by SEM-EDX, AFM, XPS, FT-IR and UV-vis spectroscopies. Three different types of PCRs with different geometrical and optical design were operated using different light sources, wavelengths and technologies. A box type photoreactor, vertical and horizontal coated quartz tubular reactors (CQTRs) were fabricated and their performances were evaluated considering BPA degradation kinetics and unit energy consumption figures (ξ, kJ energy used mg-1 BPAremoved). Vis, UV A, UV C lamps and SMD 5050 blue (450 nm) and UV (365 nm) LEDs were employed as irradiation sources to initiate photocatalytic reactions. The highest pseudo first-order reaction rate (k) and the lowest ξ value were obtained by Fetched-Sn-Ni-C-N-TiO2, positioned in vertical type reactor under UV LED irradiation as 20.5 min-1 and 56 kJ mg-1 BPAremoved respectively. Whereas, the highest BPA degradation rate (k) and the lowest ξ value for the box type reactor under 257 nm UV C irradiation were estimated as 20.3 min-1 and 1,581 kJ mg-1 BPAremoved respectively for Fetched-Sn-Ni-C-N-TiO2. Although similar reaction rates were obtained for both reactor types, energy consumption was lowered approximately 28-fold in the developed vertical positioned reactor system in addition to several other benefits. While UV LED based-PCR yielded elevated levels of BPA removal efficiency, 257 nm UV C irradiation did not contribute to BPA degradation when positioned vertically. Furthermore, obtained experimental results also revealed that Fetched-Sn-Ni-C-N-TiO2 has significant potential to function under solar irradiation .
Pharmaceuticals and personal care products (PPCPs) are becoming ubiquitous in environment, and effective removal of PPCPs from contaminated water bodies is urgently needed to avoid their potential hazards to human health. Electrocatalytic wet air oxidation (ECWAO) process is a highly efficient technology for the rapid and deep mineralization of PPCPs under room condition. In this work, the degradation behavior of the bisphenol A (BPA), a typical PPCP compounds, in the ECWAO process is comprehensively investigated. A simple kinetic model is developed to describe the removal rate of BPA as a response to the initial concentration of BPA and intensity of electric field. BPA removal in the ECWAO process is accompanied by its partial mineralization, with p-isopropenyl phenol, benzoquinone and propanedioic acid as intermediate products. At last, the performances of the ECWAO process in treating BPA and other two PPCP compounds, i.e. triclosan (TCS) and sulfamethoxazole (SMX), are assessed under a condition optimized by the kinetic model. The results demonstrate the ECWAO process is able to totally eliminate the toxicity of PPCPs-contaminated waters at low energy consumption. Notably, the treated-waters show good aerobic biodegradabilities, enabling such a process a prospective pretreatment for coupling with aerobic biological process.
MicroRNAs are short non-coding RNAs that have been widely recognized as key mediators in the epigenetic control of gene expression and which are present in virtually all cells and tissues studied. These regulatory molecules are generated in multiple steps in a process called microRNA biogenesis. Distinct microRNA expression patterns during the different stages of oocyte and embryo development suggest important regulatory roles for these small RNAs. Moreover, studies antagonizing specific microRNAs and enzymes in microRNA biogenesis pathways have demonstrated that interference with normal miRNA function leads to infertility and is associated with some reproductive abnormalities. Endocrine disrupting chemicals such as Bisphenol A (BPA) are synthetic hormone mimics that have been found to negatively impact reproductive health. In addition to their direct effects on gene expression, these chemicals are widely implicated in the disruption of epigenetic pathways, including the expression and activity of miRNAs, thereby altering gene expression. In this review, the roles of microRNAs during mammalian oocyte and embryo development are outlined and the different mechanisms by which endocrine disruptors such as BPA interfere with these epigenetic regulators to cause reproductive problems is explored.
252 Radionuclides, whether manmade or natural in origin, are present in the environment. These radioactive materials can contaminate food and can affect our health. Long-term consumption of radiological contaminated foods can damage DNA, resulting in the mutation of genes contained in the DNA and lead to cancer. When exposed, the degree of harm to human health depends on the type and the dose of radionuclides. It is also critical to know the radioactivity of the contaminated food. The common radionuclides found in food are the naturally occurring radionuclides such as Potassium-40, Uranium238, Radium-226, and their associated progeny. The manmade radionuclides can also be discharged into the environment following a major nuclear incident. Iodine-131 is an immediate concern since it’s distributed over a large area and rapidly transferred from contaminated feed into milk. Other radioisotopes that could be of long-term concern if released are Cesium-134, Cesium-137, Strontium-90, Strontium-89, and Plutonium. They can remain in the environment for a long time. Derived intervention levels as setting limits and the protective actions are used to determine the levels of radionuclides in human food and to reduce the amount of contamination.
Bisphenol A (BPA) is a synthetic unit of polycarbonate polymers and epoxy resins, the types of plastics that could be found in essentially every human population and incorporated into almost every aspect of the modern human society. BPA polymers appear in a wide range of products, from liquid storages (plastic bottles, can and glass linings, water pipes and tanks) and food storages (plastics wraps and containers), to medical and dental devices. BPA polymers could be hydrolyzed spontaneously or in a photo- or temperature-catalyzed process, providing widespread environmental distribution and chronic exposure to the BPA monomer in contemporary human populations. Bisphenol A is also a xenoestrogen, an endocrine-disrupting chemical (EDC) that interferes with the endocrine system mimicking the effects of an estrogen and could potentially keep our endocrine system in a constant perturbation that parallels endocrine disruption arising during pregnancy, such as insulin resistance (IR). Gestational insulin resistance represents a natural biological phenomenon of higher insulin resistance in peripheral tissues of the pregnant females, when nutrients are increasingly being directed to the embryo instead of being stored in peripheral tissues. Gestational diabetes mellitus may appear in healthy non-diabetic females, due to gestational insulin resistance that leads to increased blood sugar levels and hyperinsulinemia (increased insulin production from the pancreatic beta cells). The hypothesis states that unnoticed and constant exposure to this environmental chemical might potentially lead to the formation of chronic low-level endocrine disruptive state that resembles gestational insulin resistance, which might contribute to the development of diabetes. The increasing body of evidence supports the major premises of this hypothesis, as exemplified by the numerous publications examining the association of BPA and insulin resistance, both epidemiological and mechanistic. However, to what extent BPA might contribute to the development of diabetes in the modern societies still remains unknown. In this review, I discuss the chemical properties of BPA and the sources of BPA contamination found in the environment and in human tissues. I provide an overview of mechanisms for the proposed role of bisphenol A in insulin resistance and diabetes, as well as other related diseases, such as cardiovascular diseases. I describe the transmission of BPA effects to the offspring and postulate that gender related differences might originate from differences in liver enzyme levels, such as UDP-glucuronosyltransferase, which is involved in BPA processing and its elimination from the organism. I discuss the molecular mechanisms of BPA action through nuclear and membrane-bound ER receptors, non-monotonic dose response, epigenetic modifications of the DNA and propose that chronic exposure to weak binders, such as BPA, may mimic the effects of strong binders, such as estrogens.
Additives and monomers are integral components of plastics or polymers. Bisphenol A (BPA), nonylphenol (NP), and polybrominated diphenyl ethers (PBDEs) are the common monomer and additives used primarily to improve the quality of plastic materials. They are used as antioxidants, stabilizers, plasticizers, and flame retardants in plastics that are in turn used in the manufacture of a wide range of consumer and industrial products. In this chapter, the release of BPA, NP, and PBDEs from waste plastic materials is presented. A brief background of the physical and chemical characteristics of BPA, NP, and PBDEs, and other factors that influence the release of these monomer and additives from plastics, is also discussed. The overview of the consequential occurrence of these compounds in leachates from landfills and/or municipal solid waste (MSW) dumping sites provides evidence on the release of BPA, NP, and PBDEs from dumped plastic materials.
Current initiatives for waste-handling in a circular economy favor prevention and recycling over incineration or landfilling. However, the impact of such a transition on environmental emissions of contaminants like bisphenol A (BPA) during waste-handling is not fully understood. To address this, a material flow analysis (MFA) was constructed for selected waste categories in Norway, for which the amount recycled is expected to increase in the future; glass, vehicle, electronic, plastic and combustible waste. Combined, 92 tons/y of BPA are disposed of via these waste categories in Norway, with 98.5% associated with plastic and electronic waste. During the model year 2011, the MFA showed that BPA in these waste categories was destroyed through incineration (60%), exported for recycling into new products (35%), stored in landfills (4%) or released into the environment (1%). Landfilling led to the greatest environmental emissions (up to 13% of landfilled BPA), and incinerating the smallest (0.001% of incinerated BPA). From modelling different waste management scenarios, the most effective way to reduce BPA emissions are to incinerate BPA-containing waste and avoid landfilling it. A comparison of environmental and human BPA concentrations with CoZMoMAN exposure model estimations suggested that waste emissions are an insignificant regional source. Nevertheless, from monitoring studies, landfill emissions can be a substantial local source of BPA. Regarding the transition to a circular economy, it is clear that disposing of less BPA-containing waste and less landfilling would lead to lower environmental emissions, but several uncertainties remain regarding emissions of BPA during recycling, particularly for paper and plastics. Future research should focus on the fate of BPA, as well as BPA alternatives, in emerging reuse and recycling processes, as part of the transition to a circular economy.
A sensitive electrochemical sensor for determining bisphenol A(BPA) was designed. The sensor was a glassy carbon electrode modified with the surfactant cetyltrimethylammonium bromide and the ionic liquid 1-decyl-3-methylimidazolium tetrafluoroborate. The ability of the new sensor to measure BPA was investigated in cyclic voltammetry experiments. Under optimized conditions, the sensor gave a linear response range for BPA of 2.19×10−7―3.28×10−5 mol/L and a detection limit of 7.31×10−8 mol/L(S/N=3). BPA could be determined with a lower detection limit, a wider linear range, and more sensitivity using the sensor than using other electrochemical sensors or high performance liquid chromatography with UV detection. The new sensor was used to determine BPA in tap water with recoveries of 97.5%―98.7% and a relative standard deviation <2.9%. The results show that the sensor can be used to determine trace BPA concentrations in tap water.
Background:
In this study, the authors quantitatively determined the bisphenol A (BPA) leached from intraoral materials during simulated intraoral exposure.
Methods:
The authors subjected samples of intraoral materials to simulated abrasion, immersion in artificial saliva, thermal shock via temperature cycling, and simulated intraoral exposure. The authors collected sample aliquots for up to 2 weeks after artificial saliva immersion, derivatized, and then analyzed the aliquots for BPA by gas chromatography and mass spectroscopy.
Results:
Quantifiable amounts of leached BPA were observed from only 1 of 13 intraoral materials tested: a silicone baby bottle nipple (20 micrograms). BPA leaching was only observed after 3 days of artificial saliva immersion, with no additional leaching thereafter.
Conclusions:
Under the test conditions, BPA was observed to leach from a silicone baby bottle nipple.
Practical implications:
Although the quantities of leached BPA were below the reference dose for daily intake, investigators have shown a possible association between low levels of BPA and many medical disorders. BPA exposure, and thus the use of the leaching material identified in this study, should be reduced or eliminated.
Despite many studies on the effects of perinatal Bisphenol A (BPA) exposure on the brain, its effects on brain estrogen receptor (ERα) expression during puberty remain unclear. Here, mice were injected subcutaneously with BPA (50μg/kg), estradiol (10μg 17β-E2/kg) or oil (0.05ml sesame oil) daily during puberty (postnatal days 23-30). Immunohistochemistry was used to examine changes in ERα immunoreactive neurons in different brain regions. Compared to control animals, pubertal exposure to BPA significantly increased ERα immunoreactive neurons in the bed nucleus of the stria terminalis (BST), arcuate hypothalamic nucleus (Arc), ventromedial hypothalamic nucleus (VMH) and medial amygdaloid nucleus (MeA) in females. E2 exposure during puberty also increased ERα immunoreactive neurons in the lateral septum (LS) of females. No effect was detected in males. These results indicate that the effects of estrogenic chemicals on ERα immunoreactive neurons are sex-dependent.
We tested some resin-based composites used in dentistry for their estrogenic activity. A sealant based on bisphenol-A diglycidylether methacrylate (bis-GMA) increased cell yields, progesterone receptor expression, and pS2 secretion in human estrogen-target, serum-sensitive MCF7 breast cancer cells. Estrogenicity was due to bisphenol-A and bisphenol-A dimethacrylate, monomers found in the base paste of the dental sealant and identified by mass spectrometry. Samples of saliva from 18 subjects treated with 50 mg of a bis-GMA-based sealant applied on their molars were collected 1 hr before and after treatment. Bisphenol-A (range 90-931 micrograms) was identified only in saliva collected during a 1-hr period after treatment. The use of bis-GMA-based resins in dentistry, and particularly the use of sealants in children, appears to contribute to human exposure to xenoestrogens.
A method for the determination of bisphenol A according to the European Union guideline, which establishes a limit of 0.1
ng/mL for organic pollutants in water, is proposed. The method involves a micro liquid—liquid extraction using dichloromethane
followed by a silylation step. Identification and quantitation are performed with gas chromatography—mass spectrometry, using
an HP-5MS column. The retention time is 7.02 min. Quantitation is carried out using single-ion monitoring (SIM) at m/z 73, 357, and 372. A clean-up is not necessary using SIM mode. Deuterated anthracene (2H10-anthracene) is used as an internal standard. The method is applied to the determination of bisphenol A at very low concentration
levels (10.0–250.0 ng/L) in different types of natural water samples. The detection limit obtained is 0.4 ng/L. Recovery efficiencies
are close to 100% in all cases.
Recently, it was reported that Bisphenol-A (BPA) was released from one fissure sealant (Delton) into saliva causing estrogenic activity in vitro. The aim of this study was to chemically analyze the BPA content of different fissure sealant resin monomers and their release of BPA under hydrolytic conditions. BPA content was first measured in commercially available monomers of bisphenol-A glycidyldimethacrylate (Bis-GMA), bisphenol-A dimethacrylate (Bis-DMA) and bisphenol-A diglycidylether (BADGE). Then, Bis-GMA-monomer and Bis-DMA-monomer in methanol were subjected to pH values of 0 to 11 for 30 minutes at 50 degrees C, to porcine liver esterase, and to pooled saliva for up to 24 hours. The BPA-content was determined by high-performance liquid chromatography (HPLC). Bis-GMA-monomer and BADGE-monomer from one manufacturer did not contain any detectable amounts of BPA (< or = 2 ppm); Bis-DMA and BADGE-monomer from a second manufacturer contained BPA quantities of 4-155 ppm. For Bis-GMA-monomer, no BPA could be detected under any hydrolytic conditions chosen (detection limit: < or = 1%). For Bis-DMA-monomer an increase of BPA was observed at pH 11, resulting in a conversion of approx. 100% Bis-DMA to BPA. When Bis-DMA was subjected to esterase, a conversion of 82.5% resulted after 24 h; saliva led to an 81.4% conversion of Bis-DMA after 24 h. Hence, we conclude that the results reported in the literature may be attributed to the Bis-DMA-content of the fissure sealant tested (Delton). No BPA-release is expected under physiologic conditions from fissure sealants based on Bis-GMA if pure base monomers are used.
Proteins are susceptible to oxidation by reactive oxygen species, where the type of damage induced is characteristic of the denaturing species. The induction of protein carbonyls is a widely applied biomarker, arising from primary oxidative insult. However, when applied to complex biological and pathological conditions it can be subject to interference from lipid, carbohydrate and DNA oxidation products. More recently, interest has focused on the analysis of specific protein bound oxidised amino acids. Of the 22 amino acids, aromatic and sulphydryl containing residues have been regarded as being particularly susceptible to oxidative modification, with L-DOPA from tyrosine, ortho-tyrosine from phenylalanine; sulphoxides and disulphides from methionine and cysteine respectively; and kynurenines from tryptophan. Latterly, the identification of valine and leucine hydroxides, reduced from hydroperoxide intermediates, has been described and applied. In order to examine the nature of oxidative damage and protective efficacy of antioxidants the markers must be thoroughly evaluated for dosimetry in vitro following damage by specific radical species. Antioxidant protection against formation of the biomarker should be demonstrated in vitro. Quantification of biomarkers in proteins from normal subjects should be within the limits of detection of any analytical procedure. Further to this, the techniques for isolation and hydrolysis of specific proteins should demonstrate that in vitro oxidation is minimised. There is a need for the development of standards for quality assurance material to standardise procedures between laboratories. At present, antioxidant effects on protein oxidation in vivo are limited to animal studies, where dietary antioxidants have been reported to reduce dityrosine formation during rat exercise training. Two studies on humans have been reported last year. The further application of these methods to human studies is indicated, where the quality of the determinations will be enhanced through inter-laboratory validation.
We examined whether orally administered bisphenol A transfers from the maternal rat to the fetus. After oral dose of 10 mg/kg bisphenol A, it immediately appeared in maternal blood, and transferred into the fetuses. The concentration of bisphenol A in both maternal blood plasma and fetuses peaked within I h after administration. The values were approximately 34 ppb and 11 ppb, respectively. At 3 h, the concentration of bisphenol A in maternal blood plasma had decreased to approximately 10% of the peak value. The 3-h decrease in fetuses was only about 40% of the peak, and by 24 h, the fetal concentration had increased again to the nearly 70% of the peak value. The results suggest that bisphenol A might easily pass through the placental barrier, unlike sex hormones such as estrogen.
Four biomarkers of neuronal protein oxidation [W/S ratio of MAL-6 spin-labeled synaptosomes, phenylhydrazine-reactive protein carbonyl content, glutamine synthetase (GS) activity, creatine kinase (CK) activity] in three brain regions [cerebellum, inferior parietal lobule (IPL), and hippocampus (HIP)] of Alzheimer's disease (AD)-demented and age-matched control subjects were assessed. These endpoints indicate that AD brain protein may be more oxidized than that of control subjects. The W/S ratios of AD hippocampal and inferior parietal synaptosomes are 30 and 46% lower, respectively, than corresponding values of tissue isolated from control brain; however, the difference between the W/S ratios of AD and control cerebellar synaptosomes is not significant. Protein carbonyl content is increased 42 and 37% in the Alzheimer's HIP and IPL regions, respectively, relative to AD cerebellum, whereas carbonyl content in control HIP and IPL is similar to that of control cerebellum. GS activity decreases an average of 27% in the AD brain; CK activity declines by 80%. The brain regional variation of these oxidation-sensitive biomarkers corresponds to established histopathological features of AD (senile plaque and neurofibrillary tangle densities) and is paralleled by an increase in immunoreactive microglia. These data indicate that senile plaque-dense regions of the AD brain may represent environments of elevated oxidative stress.
The effectiveness of electrochemical methods in purification of synthetic wastewaters containing bisphenol-A has been tested. The role of electrode material and electrolysis parameters have been considered. The kinetics of bisphenol oxidation have been followed using different analytical techniques and a degradation mechanism has been proposed.
In the present study we have investigated the ability of bisphenol A to be converted to reactive metabolite(s) and its potential to bind to DNA. In this in vitro study we show that bisphenol A is oxidized by 70% to bisphenol o-quinone. The evidence for the formation of bisphenol o-quinone was shown by UV, IR and GC-MS. The new product, bisphenol o-quinone, had a maximum UV absorption at 386 nM, the appearance of an IR characteristic of unsaturated carbonyl (1690 cm-1) and a mass of 242. The chemical reaction of deoxyguanosine monophosphate (dGMP) or DNA with bisphenol o-quinone produced 6-8 adducts. The in vitro incubation of DNA with bisphenol A in the presence of peroxidase activation system also produced one major and seven minor adducts. The chromatographic mobilities of major DNA adducts four and six formed by bisphenol A in the presence of peroxidase activation system closely matched those of spots four and six obtained by chemical reaction between DNA or dGMP with bisphenol o-quinone. Based on these data it appears that bisphenol A is converted to DNA binding metabolites in vitro. Whether irreversible binding of bisphenol A to DNA through metabolic activation may be responsible for some of the toxic effects produced by bisphenol A is not clear.
Peptides containing either glycine and methionine, or glycine, methionine and histidine at various locations were oxidized by the dithiothreitol/ferric chloride system in phosphate buffer. The yields of peptide degradation and sulfoxide formation were measured as a function of peptide sequence and pH. In general little change of the final yields of peptide degradation is observed whereas the final yields of sulfoxide formation progressively decrease on going from pH 6.0 to 8.0. The pH profiles vary with the structure of the respective peptide. Efficient sulfoxide formation occurred when histidine and methionine were present within the same peptides sequence, and particularly when methionine was located at the C-terminus of the peptide. Added superoxide dismutase, catalase, and methanol did neither promote nor inhibit both the degradation of peptide and the formation of sulfoxide excluding free superoxide, hydrogen peroxide, and hydroxyl radicals as responsible reactive oxygen species. The observations are rationalized by invoking a pH-dependent conversion of an efficiently sulfoxide yielding oxidant into another oxidant which still degrades peptides but does not form methionine sulfoxide. The first might be a metal-bound peroxide or peroxyl species which converts into a metal-bound or 'complexed' hydroxyl radical.
This study was to investigate developmental toxicity of some selected low molecular weight antioxidants, by utilising sea urchin embryos and gametes as model system. Sea urchin embryos or sperm were exposed at different developmental stages to L-methionine or some selected low molecular weight antioxidants: a) N-acetylcysteine; b) L-carnosine; c) L-homocarnosine, and d) L-anserine. L-methionine displayed developmental toxicity at levels > or = 10(-5) M, whereas the other agents tested were mostly active at levels > or = 10(-4) M. When embryos were exposed to 10(-4) M L-methionine or N-acetylcysteine at different developmental stages, the most severe effects were exerted by early exposures (0 to 2 hr after fertilisation), whereas later exposures turned to lesser or no effects. Cytogenetic analysis of L-methionine-exposed embryos showed a significant mitogenic effect and increase of mitotic aberrations. Fertilisation success was decreased by L-methionine (10(-6) M to 10(-3) M) added at the moment of fertilisation, with increasing developmental and cytogenetic abnormalities in the offspring. The formation of reactive oxygen species in embryos and gametes was determined by: a) analysing the DNA oxidative product, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and b) luminol-dependent chemiluminescence. The results showed that: 1) 8-OHdG levels were increased during embryogenesis; 2) fertilisation was associated with a double-wave luminol-dependent chemiluminescence emission; 3) luminol-dependent chemiluminescence was maximal in cleavage, declining down to zero in plutei, and 4) an embryotoxic L-methionine or N-acetylcysteine level (10(-4) M) turned to a decrease in reactive oxygen species formation. The data suggest that L-methionine- or N-acetylcysteine-induced developmental toxicity is confined to early stages. A role for oxidative activity is suggested in modulating cell differentiation and embryogenesis, consistent with antioxidant-induced damage to early life stages.
Twenty-four brands of plastic baby feeding bottles were purchased and all were found to be made of polycarbonate. Taking a batch of one representative sample, the polymer was tested for stability and possible release of bisphenol A following domestic practice of sterilization. Sterilization was by alkaline hypochlorite, steam, or washing in an automatic dishwasher at 65 degrees C with detergent. A total of 20 cycles of sterilization and subsequent food use were performed for each of the three procedures. Bisphenol A migration was in all cases not detectable in infant feed using a very sensitive method of liquid chromatography with fluorescence detection with a 0.03 mg/kg detection limit.
The lipids of high density lipoproteins (HDL) are initially oxidized in preference to those in low density lipoprotein when human plasma is exposed to aqueous peroxyl radicals. In this work we report on the relative susceptibility of HDL protein and lipid to oxidation and on the role HDL's alpha-tocopherol (alpha-TOH) plays in modulating protein oxidation. Exposure of isolated HDL to either low fluxes of aqueous peroxyl radicals, Cu2+ ions, or soybean lipoxygenase resulted in the oxidation of apoAI and apoAII during the earliest stages of the reaction, i.e. after consumption of ubiquinol-10 and in the presence of alpha-TOH. Hydro(pero)xides of cholesteryl esters and phospholipids initially accumulated together with specific oxidized forms of apoAI and apoAII, separated by high pressure liquid chromatography. The specific oxidized forms of apoAI were 16 and 32 mass units heavier than those of the native apolipoproteins and contained 1 and 2 methionine sulfoxide residues per protein, respectively. The third methionine residue in apoAI, as well as Trp residues, remained unoxidized during the earliest stages of HDL oxidation examined. Exposure of isolated apoAI to peroxyl radicals, Cu2+, or soybean lipoxygenase resulted in nonspecific (for peroxyl radicals) or no discernible protein oxidation (Cu2+ and soybean lipoxygenase). This indicated that the formation of the specific oxidized forms of apoAI observed with native HDL was not the result of direct reaction of these oxidants with the apolipoprotein. In vitro and in vivo enrichment of HDL with alpha-TOH resulted in a dose-dependent increase in the extent of peroxyl radical-induced formation of HDL cholesteryl ester hydroperoxides (r = 0.96) and cholesteryl ester hydroxides (r = 0. 92), as well as the loss of apoAI (r = 0.96) and apoAII (r = 0.94). alpha-TOH enrichment also enhanced HDL lipid and protein oxidation induced by Cu2+ or soybean lipoxygenase. These results indicate that the earliest stages of HDL oxidation are accompanied by the oxidation of specific methionine residues in apoAI and apoAII and that in the absence of co-antioxidants, alpha-TOH can promote this process.
Bisphenol A (CAS 85-05-7) may be released into the environment through its use and handling, and permitted discharges. BPA is moderately soluble (120 to 300 mg/L at pH 7), may adsorb to sediment (Koc 314 to 1524), has low volatility, and is not persistent based on its rapid biodegradation in acclimated wastewater treatment plants and receiving waters (half-lives 2.5 to 4 days). BPA is "slightly to moderately" toxic (algal EC50 of 1000 micrograms/L) and has low potential for bioaccumulation in aquatic organisms (BCFs 5 to 68). The chronic NOEC for Daphnia magna is > 3146 micrograms/L. Surface water concentrations are at least one to several orders of magnitude lower than chronic effects, with most levels nondetected.
The authors critically surveyed research dealing with the release of resin components from dental composites and the potential of these agents to mimic or disrupt estrogenic cell responses.
The studies reviewed included those on synthetic methods used to make bisphenol A glycidyl methacrylate, or BIS-GMA, and the biological effects of this resin in cell culture and animals. The estrogenic effect of bisphenol A was targeted because bisphenol A is present as an impurity in some resins (BIS-GMA) and as a degradation product from other resins (bisphenol A dimethacrylate, or BIS-DMA).
The outcomes of this review revealed that short-term administration of BIS-GMA and/or bisphenol A in animals or cell cultures can induce changes in estrogen-sensitive organs or cells. However, considering the dosages and routes of administration and the modest response of estrogen-sensitive target organs, the authors conclude that the short-term risk of estrogenic effects from treatments using bisphenol A-based resins is insignificant. Long-term effects need to be investigated further.
Commonly used dental resins should not be of concern to the general public; however, pharmacological evaluation of dental materials is needed to ensure biologically safe and therapeutically effective substances.
To quantify the leaching of bisphenol A into water, various samples of plastic waste were cut into small pieces, soaked in water for two weeks at room temperature in the dark, and the concentration of bisphenol A in the water determined by gas chromatography/mass spectrometry (GC/MS). The amount of bisphenol A leached from the plastic wastes ranged from undetectable to 139 micrograms/g. The detection limit was 2 ng/g when 100 g of plastic waste was used. Polyvinyl chloride products yielded the highest concentrations because bisphenol A is used in its manufacture as a stabilizer.
The aim of this study was to establish an easy and accurate method for the determination of bisphenol-A (BPA) in the body liquid such as serum and urine. Two high-performance liquid chromatography (HPLC) systems, HPLC with electrochemical detector (ED), and HPLC with mass spectrometry (MS) using electrospray ionization (ESI) interface were used for the assay in the serum samples prepared with solid-phase extraction method. Water or EtOH at a concentration below 50% was suitable for the extraction of BPA from serum. The limit of detection of BPA was 0.2 ng ml(-1) for the HPLC-ED method and 0.1 ng ml(-1) for HPLC-MS. There was a good correlation between the data obtained by the two HPLC systems. BPA concentrations in healthy human serum were low (0-1.6 ng ml(-1)). From various commercial fetal bovine serum and sheep plasma, however, significant amounts of BPA were detected. Since no BPA was detected from sheep plasma immediately after collection, the high amounts of BPA were considered to be caused by the handling of blood during the preparation of the products after blood collection. In vitro study showed that the amount of BPA leached from polycarbonate tube into sheep plasma were 40 times larger than those into water and the leached amount of BPA depended on the temperature (37 degrees C>20 degrees C>5 degrees C).
The reactivity of bisphenol A (BPA), diethylstilbestrol (DEST) 2,2'-biphenol (22'BP), 4,4'-biphenol (44'BP) and hydroquinone (HQ) as radical scavengers was examined in 2,2'-azobisisobutyronitrile (AIBN)- and benzoyl peroxide (BPO)-induced methyl methacrylate (MMA) polymerization with respect to kinetic considerations. The initial rate of polymerization (IRP) was found to decrease in the order: 44'BP > BPA, DEST > 22'BP > HQ, while the stoichiometric factor (n) of free radicals trapped by phenolic moiety decreased in the order: 44'BP (2.3) > HQ (2.0) > BPA, DEST (1.8) > 22'BP (0.8). It was found that BPA was a more highly efficient inhibitor than HQ and that HQ acts as a retarder at higher concentrations in the BPO system. The high activity of BPA indicated that BPA is probably oxidized by a radical interaction in the dental resin system.
In order to ascertain whether an estrogenic bisphenol A is produced from bisphenol A-related monomers by chemical-induced hydrolysis and to clarify their hydrolytic mechanisms, bisphenol A dimethacrylate (Bis-DMA) and bisphenol A bis(glycidyl methacrylate) (Bis-GMA) were reacted with phosphoric acid, hydrochloric acid, and sodium hydroxide in methanol or methanol/water mixed media at 37 degrees C. Amounts of monomethacrylate intermediates as well as bisphenol A (BPA) were determined by the use of high-performance liquid chromatography (HPLC), and time-conversion curves of hydrolytic products were prepared. BPA and bisphenol A monomethacrylate were produced by acid-catalyzed hydrolysis of Bis-DMA. Bis-GMA was partly converted into monomethacrylate by phosphoric acid and into monomethacrylate and 2,2-bis[4-(2,3-dihydroxypropoxy) phenyl]propane (BHP) by hydrochloric acid. Hydrolytic reactions by sodium hydroxide were completed almost within 1 day, resulting in the production of BPA from Bis-DMA, and BHP from Bis-GMA. No BPA was formed from Bis-GMA by chemical-induced hydrolysis. The hydrolytic behaviors of these monomers were discussed.
This study was designed to determine whether bisphenol A (BPA) is eluted from hemodialyzers in which polycarbonate and polysulfone based on BPA are used as materials. Four types of polysulfone hemodialyzer (PS hemodialyzer: PS-A, PS-B, PS-C and PS-D) and an ethylene-vinyl alcohol copolymer dialyzer (EVAL hemodialyzer) were used in this study. In the PS-C, PS-D and EVAL hemodialyzers, polycarbonate was used in the case headers at both ends of the hemodialyzer. In in vitro experiments, the hemodialyzers were filled with reverse osmotic water, and BPA concentrations were measured. Saline solution (200 ml) was then circulated through a blood circuit tube connected to the hemodialyzer, and BPA concentrations in the saline solution were measured. In in vivo experiments, BPA concentrations in whole blood samples from hemodialysis patients treated with PS-C (n = 3) and PS-D (n = 3) hemodialyzers were measured. In in vitro experiments, BPA was detected in the effluents of the PS-C, PS-D and EVAL hemodialyzers. In in vivo experiments, BPA was detected in whole blood samples from hemodialysis patients treated with the PS-D hemodialyzer (mean value, 0.77 ppb). This is the first report of BPA elution from hemodialyzers in which polycarbonate and polysulfone are used, and also the first report of detection of BPA in whole blood samples from patients on hemodialysis.
A change in bisphenol-A (BPA) concentration leached from polycarbonate (PC) tube to the phosphatidyl ethanolamine (PhE)-containing water was compared to water only. Time-dependent increase in BPA concentration was observed in both samples at 37 degrees C. The leaching velocity of BPA to water was three times faster than that to PhE-containing water and BPA concentration in water reached to 55.8 ng/ml 5 weeks later. When BPA was determined immediately after BPA addition of various concentration of PhE up to 2.5mg/ml to water, the BPA recoveries were over 93%. But, when incubated at 37 degrees C for a special time, BPA concentration in PhE-containing water in glass tube decreased time-dependently. In the presence of H2O2, time and Fe3+ dose-dependent decrease in the BPA concentration particularly, a drastic decrease above 0.44 mM Fe3+ was observed. These results suggest that BPA would be decomposed by radical oxygen including lipoperoxides. An addition of serum prevented BPA decrease from radical oxygen to a great extent but could not recover the BPA decrease. Thiobarbituric acid (TBA) value, a good parameter of lipid oxidation, decreased gradually in the mixture of H9O2 and Fe3+ in the presence of BPA, implying an inhibition of lipid oxidation due to BPA oxidation by radical oxygen.
In this study, (1) change in bisphenol-A (BPA) leached from polycarbonate (PC) tube to water samples at 37 degrees C, (2) effect of reactive oxygen species (ROS) produced by Fenton reaction on BPA recovery and thiobarbituric acid (TBA) value with or without generally existing environmental substances such as alcohol, lipids and NaCl, were investigated. Amounts of BPA leached from PC tube to water samples containing lipids possessing unsaturated fatty acid with high TBA values were significantly lower than the amount of BPA to water only, and addition of NaCl to lipid containing water further decreased BPA concentration. The result indicates that BPA could be degraded by lipoperoxides formed by auto-oxidation of lipid, and NaCl plays an important role in BPA degradation. In the presence of ROS, BPA recovery was the lowest in water and addition of EtOH increased in both BPA recovery and TBA value, suggesting that EtOH could play a role as scavenger of ROS on the oxidative BPA degradation. Furthermore, the higher the concentration of lipid and/or NaCl, the lower the BPA recovery and TBA value. Physiologically and environmentally important concentrations of NaCl could enhance oxidative degradation of BPA in the presence of ROS.
In this study, (1) change in the concentration of bisphenol A (BPA) leached from polycarbonate (PC) tube to control water (BPA free), seawater and river water at 20 and 37 degrees C as a function of time, (2) the fate of BPA caused by addition of H(2)O(2) and Fe(3+) to seawater containing BPA leached from PC tube were assessed. BPA leached from PC tube to all water samples increased with the ascendant of temperature and with the passage of time. The BPA leaching velocity in seawater was the fastest in three samples (11 ng/day for seawater, 4.8 ng/day for river water 0.8 ng/day for control water at 37 degrees C).BPA leaching velocity from PC tube was significantly high at pH 8 (50 mM Na(2)HPO(4)) and increased dose-dependently. There was no difference in the velocity of BPA among the 50 mM phosphate-buffers at pH 6.5, 7.0 and 7.5. BPA was leached three times higher by addition of Na(+) than K(+). However, the higher the K(+) concentration, the larger the BPA leached from PC tube. Na(+) mixed with PO(4)(-) was effective on BPA leaching from PC tube, but not with SO(4)(-) or Cl(-). The results suggested that BPA leaching from PC tube would be attributed to the concentration of bibasic phosphate such as Na(2)HPO(4) and K(2)HPO(4) in water samples. BPA was degraded in both control water and seawater in the presence of radical oxygen species, but the degradation rate was lower in seawater than in control water, suggesting that anti-oxidative system exists in seawater. Neo-synthesized substance in both control water and seawater in the presence of reactive oxygen species was identified as BPA-quinone by LC-MS.
The plasma and urine levels of 19 free amino acids as determined microbiologically in fasting, healthy, young males are reported.