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Xie R, Xu Y, Ma M, Wang X, Zhang L, Wang Z. First metabolic profiling of 4-n-nonylphenol in human liver microsomes by integrated approaches to testing and assessment: Metabolites, pathways, and biological effects. JOURNAL OF HAZARDOUS MATERIALS 2023; 447:130830. [PMID: 36682248 DOI: 10.1016/j.jhazmat.2023.130830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 06/17/2023]
Abstract
4-n-nonylphenol (4-n-NP), a typical endocrine disrupting chemical, has been so far frequently detected in various environmental mediums and editable food. However, the specific metabolic pathways in human and potential adverse effects of metabolites have not been elucidated yet. Here, metabolic profiling of 4-n-NP in human liver microsome (HLM) was comprehensively characterized by integrated approaches of testing and assessment. A total of 21 metabolites were identified using nontarget analysis with high-resolution mass spectrum, including three groups of unique phase I metabolites first determined in HLM. Seven various metabolic pathways of 4-n-NP were identified by both in silico and in vitro, and CYP1A2, 2C19, and 2D6 were the mainly participating enzymes. Two secondary metabolites with carbonyl groups on side chains (M4, M7) presented most abundant in HLM, which were also predicted to have high binding affinities towards HPG-axis-related receptors (AR, ER, and PR). ESRs (estrogen receptors) were shared core protein targets for all metabolites revealed by protein-protein interaction networks. Biological functions enrichment analysis indicated that 4-n-NP metabolites might primarily involve in ESR-mediated signaling, GPCR ligand binding, Class A/1 (Rhodopsin-like receptors) and metabolism-related pathways. These findings of 4-n-NP metabolites, pathways, and biological effects provide insightful information for its environmental exposure and risk assessment.
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Affiliation(s)
- Ruili Xie
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiping Xu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Mei Ma
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xiaodan Wang
- China National Center for Food Safety Risk Assessment, Beijing 100022, China
| | - Lei Zhang
- China National Center for Food Safety Risk Assessment, Beijing 100022, China
| | - Zijian Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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2
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Clifford MN, King LJ, Kerimi A, Pereira-Caro MG, Williamson G. Metabolism of phenolics in coffee and plant-based foods by canonical pathways: an assessment of the role of fatty acid β-oxidation to generate biologically-active and -inactive intermediates. Crit Rev Food Sci Nutr 2022; 64:3326-3383. [PMID: 36226718 DOI: 10.1080/10408398.2022.2131730] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
ω-Phenyl-alkenoic acids are abundant in coffee, fruits, and vegetables. Along with ω-phenyl-alkanoic acids, they are produced from numerous dietary (poly)phenols and aromatic amino acids in vivo. This review addresses how phenyl-ring substitution and flux modulates their gut microbiota and endogenous β-oxidation. 3',5'-Dihydroxy-derivatives (from alkyl-resorcinols, flavanols, proanthocyanidins), and 4'-hydroxy-phenolic acids (from tyrosine, p-coumaric acid, naringenin) are β-oxidation substrates yielding benzoic acids. In contrast, 3',4',5'-tri-substituted-derivatives, 3',4'-dihydroxy-derivatives and 3'-methoxy-4'-hydroxy-derivatives (from coffee, tea, cereals, many fruits and vegetables) are poor β-oxidation substrates with metabolism diverted via gut microbiota dehydroxylation, phenylvalerolactone formation and phase-2 conjugation, possibly a strategy to conserve limited pools of coenzyme A. 4'-Methoxy-derivatives (citrus fruits) or 3',4'-dimethoxy-derivatives (coffee) are susceptible to hepatic "reverse" hydrogenation suggesting incompatibility with enoyl-CoA-hydratase. Gut microbiota-produced 3'-hydroxy-4'-methoxy-derivatives (citrus fruits) and 3'-hydroxy-derivatives (numerous (poly)phenols) are excreted as the phenyl-hydracrylic acid β-oxidation intermediate suggesting incompatibility with hydroxy-acyl-CoA dehydrogenase, albeit with considerable inter-individual variation. Further investigation is required to explain inter-individual variation, factors determining the amino acid to which C6-C3 and C6-C1 metabolites are conjugated, the precise role(s) of l-carnitine, whether glycine might be limiting, and whether phenolic acid-modulation of β-oxidation explains how phenolic acids affect key metabolic conditions, such as fatty liver, carbohydrate metabolism and insulin resistance.
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Affiliation(s)
- Michael N Clifford
- School of Bioscience and Medicine, University of Surrey, Guildford, UK
- Department of Nutrition, Dietetics and Food, Monash University, Clayton, Australia
| | - Laurence J King
- School of Bioscience and Medicine, University of Surrey, Guildford, UK
| | - Asimina Kerimi
- Department of Nutrition, Dietetics and Food, Monash University, Clayton, Australia
| | - Maria Gema Pereira-Caro
- Department of Food Science and Health, Instituto Andaluz de Investigacion y Formacion Agraria Pesquera Alimentaria y de la Produccion Ecologica, Sevilla, Spain
| | - Gary Williamson
- Department of Nutrition, Dietetics and Food, Monash University, Clayton, Australia
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3
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Fu H, Di Q, Wang J, Jiang Q, Xu Q. Toxicokinetics and distribution in female rats after chronic nonylphenol exposure. Toxicol Ind Health 2020; 36:925-935. [PMID: 33025838 DOI: 10.1177/0748233720958963] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Our previous studies have shown that continuous exposure to nonylphenol (NP) may cause female reproductive toxicity even at low doses. To better understand this toxic effect, the aim of this study was to investigate the basic characteristics of the disposal kinetics of NP under a chronic exposure scenario to simulate human exposure. Female rats were exposed to NP at three dose levels (50-, 500-, and 10,000 µg kg-1 bw day-1, low, medium, and high dose, respectively) by gavage daily for 17 weeks. Ultrahigh-performance liquid chromatography-tandem mass spectrometry was used to detect NP in rat sera and tissues. The results suggested that a two extravascular compartment model was found to better match the actual serum metabolic behavior of NP. Compared with the high-dose group, the NP absorption in the low-dose group was relatively efficient, the clearance rate was slower, and the residual amount of NP was greater. NP was found mostly in the uterus, adipose and brain tissues and to a lesser degree, in the liver, kidney, and ovary. The results indicated that the extensive organ distribution may cause corresponding toxicity even at relatively low doses.
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Affiliation(s)
- Haowei Fu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, 12579Southeast University, Nanjing, China
| | - Qiannan Di
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, 12579Southeast University, Nanjing, China
| | - Jinming Wang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, 12579Southeast University, Nanjing, China
| | - Qianqian Jiang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, 12579Southeast University, Nanjing, China
| | - Qian Xu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, 12579Southeast University, Nanjing, China
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4
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Investigation of the In Vivo Metabolism of Sibirioside A and Angoroside C in Rats by HPLC-ESI-IT-TOF-MS n. Molecules 2018; 23:molecules23102702. [PMID: 30347747 PMCID: PMC6222638 DOI: 10.3390/molecules23102702] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/16/2018] [Accepted: 10/18/2018] [Indexed: 12/19/2022] Open
Abstract
Sibirioside A and angoroside C are two important phenylpropanoid glycosides of the traditional Chinese medicine Scrophulariae Radix. High performance liquid chromatography, coupled with an ion trap time-of-flight multistage mass spectrometry equipped with electrospray ionization source (HPLC-ESI-IT-TOF-MSn), was applied to the profile and we identified the metabolites of sibirioside A and angoroside C in vivo in rats. A total of four metabolites of sibirioside A were identified: SM1, SM2 and SM3 which were known as new compounds. A total of 25 metabolites were detected for angoroside C: AM4, AM5, AM6, AM7, AM16, AM17, AM20, AM21, AM22, AM23 and AM25 which were identified to be new compounds. The main metabolic reactions were hydrolysis, reduction, hydroxylation, methylation, sulfation, and gluconylation. The prototype of sibirioside A was widely distributed in tissues found in the heart, liver, spleen, lung, kidney, stomach and small intestine of rats, and mainly distributed in the stomach, small intestine, kidney and liver. But for angoroside C, nothing was found in the viscera except the stomach and small intestine. The metabolites of sibirioside A were mainly eliminated from feces, while it was urine for the metabolites of angoroside C. Furthermore, 19 metabolites were likely to have bioactivities based on the ‘PharmMapper’ analysis, which roughly matched the known pharmacological activities of Scrophulariae Radix (SR) and the prototypes. One of the main pharmacological activities of SR in traditional Chinese medicine is anti-diabetes, and the predicted results showed that SM1, SM2, SM3, AM2, AM4, AM5, AM6, AM9, AM10, AM11, AM12, AM13, AM15, AM18, AM19, AM24, and AM25 might be used to cure diabetes. These findings provide a reference for studying the metabolism, distribution and pharmacological actions of phenylpropanoid glycosides in vivo.
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Kazemi S, Khalili-Fomeshi M, Akbari A, Kani SNM, Ahmadian SR, Ghasemi-Kasman M. The correlation between nonylphenol concentration in brain regions and resulting behavioral impairments. Brain Res Bull 2018. [DOI: 10.1016/j.brainresbull.2018.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Abstract
PURPOSE OF REVIEW The purpose of this review is to identify emerging developmental toxicants that are understudied in children's health. Exposures may arise from new products designed to improve utility, to reduce toxicity, or to replace undesirable chemicals. Exposures to less-toxic chemicals may also be significant if they are very commonly used, thereby generating widespread exposure. Sources of exposure include the workplace, personal, home, and office products; food, water, and air. RECENT FINDINGS We describe eight exposure categories that contain numerous potential developmental toxicants. References are discussed if reported in PubMed during the past decade at least 10 times more frequently than in 1990-2000. Examples included phthalates, phenols, sunscreens, pesticides, halogenated flame retardants, perfluoroalkyl coatings, nanoparticles, e-cigarettes, and dietary polyphenols. Replacements are often close structural homologs of their precursors. We suggest biomonitoring as preferred means of exposure assessment to emerging chemicals. Some existing analytic methods would require minimal modification to measure these exposures, but others require toxicokinetic and analytic investigation. SUMMARY A deliberate strategy for biomonitoring of emerging replacement chemicals is warranted, especially in view of concerns regarding developmental toxicity. To prevent adverse health effects, it is important to characterize such exposures before they become widely disseminated.
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Różalska S, Soboń A, Pawłowska J, Wrzosek M, Długoński J. Biodegradation of nonylphenol by a novel entomopathogenic Metarhizium robertsii strain. BIORESOURCE TECHNOLOGY 2015; 191:166-172. [PMID: 25989092 DOI: 10.1016/j.biortech.2015.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 05/06/2015] [Accepted: 05/07/2015] [Indexed: 06/04/2023]
Abstract
The biodegradation of nonylphenol (NP) by a newly isolated form of the larva fungal strain Metarhizium robertsii IM 6519 was investigated in this study. This isolate was capable of degrading 4-n-NP, and multiple metabolites were detected. The coexistence of parallel degradation pathways with versatile hydroxylation in different positions of the alkyl chain is a unique feature of this strain. Moreover, several metabolites previously described only in higher eukaryotes were detected in the fungal cultures. The degradation process led to the mineralization of 4-n-NP (with an efficiency of 36%), a great advantage of this strain that results in complete removal of toxic substrate from the environment.
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Affiliation(s)
- Sylwia Różalska
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Łódź, Poland
| | - Adrian Soboń
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Łódź, Poland
| | - Julia Pawłowska
- Department of Molecular Phylogenetics and Evolution, Institute of Botany, Faculty of Biology, University of Warsaw, Poland
| | - Marta Wrzosek
- Department of Molecular Phylogenetics and Evolution, Institute of Botany, Faculty of Biology, University of Warsaw, Poland
| | - Jerzy Długoński
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Łódź, Poland.
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8
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Kawaguchi S, Kuwahara R, Kohara Y, Uchida Y, Oku Y, Yamashita K. Oral exposure to low-dose of nonylphenol impairs memory performance in Sprague-Dawley rats. J Toxicol Sci 2015; 40:43-53. [PMID: 25560395 DOI: 10.2131/jts.40.43] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Nonylphenol ethoxylate (NPE) is a non-ionic surfactant, that is degraded to short-chain NPE and 4-nonylphenol (NP) by bacteria in the environment. NP, one of the most common environmental endocrine disruptors, exhibits weak estrogen-like activity. In this study, we investigated whether oral administration of NP (at 0.5 and 5 mg/kg doses) affects spatial learning and memory, general activity, emotionality, and fear-motivated learning and memory in male and female Sprague-Dawley (SD) rats. SD rats of both sexes were evaluated using a battery of behavioral tests, including an appetite-motivated maze test (MAZE test) that was used to assess spatial learning and memory. In the MAZE test, the time required to reach the reward in male rats treated with 0.5 mg/kg NP group and female rats administered 5 mg/kg NP was significantly longer than that for control animals of the corresponding sex. In other behavioral tests, no significant differences were observed between the control group and either of the NP-treated groups of male rats. In female rats, inner and ambulation values for animals administered 0.5 mg/kg NP were significantly higher than those measured in control animals in open-field test, while the latency in the group treated with 5 mg/kg NP was significantly shorter compared to the control group in step-through passive avoidance test. This study indicates that oral administration of a low-dose of NP slightly impairs spatial learning and memory performance in male and female rats, and alters emotionality and fear-motivated learning and memory in female rats only.
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De Falco M, Sellitti A, Sciarrillo R, Capaldo A, Valiante S, Iachetta G, Forte M, Laforgia V. Nonylphenol effects on the HPA axis of the bioindicator vertebrate, Podarcis sicula lizard. CHEMOSPHERE 2014; 104:190-6. [PMID: 24290296 DOI: 10.1016/j.chemosphere.2013.11.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/31/2013] [Accepted: 11/04/2013] [Indexed: 05/20/2023]
Abstract
Nonylphenol (NP) is an endocrine disruptor widely distributed in the environment. It accumulates in the lipids of living organisms and enters the human food chain. The main source of human exposure is expected to be food, drinking water and foodstuff contaminated through leaching from packaging or pesticide formulation applications. NP acts as an estrogenic compound and it is able to mimic the action of estradiol 17β (E2) by binding to the estrogen receptor (ER). The aim of the present study was to investigate the NP effects on the hypothalamic-pituitary-adrenal gland (HPA) axis of the bioindicator Podarcis sicula lizard. A time-dependent stimulation of the HPA axis and variations of both catecholamine plasma levels were showed. Moreover, NP effects on adrenal gland morphology were evaluated by light and transmission electron microscopy. Clear morphological signs of adrenal gland stimulation such as an increase of steroidogenic cord diameter and vascularization, a strong escalation of adrenaline cell number and a decrease of noradrenaline cells were observed. The notably elevated levels of adrenal hormones suggested a permanent turning on of hypothalamic corticotropin releasing factor (CRF) secretion together with a lack of the negative feedback of HPA axis, perturbing systemic responses of the organism. Our data may help to predict the biological alterations induced by NP and to extend its impact upon adrenal function.
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Affiliation(s)
- Maria De Falco
- Department of Biology, Section of Evolutionary and Comparative Biology, University Federico II of Naples, Via Mezzocannone 8, 80134 Naples, Italy.
| | - Anna Sellitti
- Department of Biology, Section of Evolutionary and Comparative Biology, University Federico II of Naples, Via Mezzocannone 8, 80134 Naples, Italy
| | - Rosaria Sciarrillo
- Department of Biological and Environmental Sciences, University of Sannio, Via Port'Arsa 11, 82100 Benevento, Italy
| | - Anna Capaldo
- Department of Biology, Section of Evolutionary and Comparative Biology, University Federico II of Naples, Via Mezzocannone 8, 80134 Naples, Italy
| | - Salvatore Valiante
- Department of Biology, Section of Evolutionary and Comparative Biology, University Federico II of Naples, Via Mezzocannone 8, 80134 Naples, Italy
| | - Giuseppina Iachetta
- Department of Biology, Section of Evolutionary and Comparative Biology, University Federico II of Naples, Via Mezzocannone 8, 80134 Naples, Italy
| | - Maurizio Forte
- Department of Biology, Section of Evolutionary and Comparative Biology, University Federico II of Naples, Via Mezzocannone 8, 80134 Naples, Italy
| | - Vincenza Laforgia
- Department of Biology, Section of Evolutionary and Comparative Biology, University Federico II of Naples, Via Mezzocannone 8, 80134 Naples, Italy
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Snedeker SM, Hay AG. The Alkylphenols Nonylphenol and Octylphenol in Food Contact Materials and Household Items: Exposure and Health Risk Considerations. MOLECULAR AND INTEGRATIVE TOXICOLOGY 2014. [DOI: 10.1007/978-1-4471-6500-2_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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11
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Jondeau-Cabaton A, Soucasse A, Jamin EL, Creusot N, Grimaldi M, Jouanin I, Aït-Aïssa S, Balaguer P, Debrauwer L, Zalko D. Characterization of endocrine disruptors from a complex matrix using estrogen receptor affinity columns and high performance liquid chromatography-high resolution mass spectrometry. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:2705-2720. [PMID: 23314706 DOI: 10.1007/s11356-012-1458-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 12/27/2012] [Indexed: 06/01/2023]
Abstract
Complex mixtures of contaminants with potential adverse effects on human health and wildlife are found in the environment and in the food chain. These mixtures include numerous anthropogenic compounds of various origins and structures, which may behave as endocrine disruptors. Mixture's complexity is further enhanced by biotic and abiotic transformations. It is therefore necessary to develop new strategies allowing the identification of the structure of known, as well as unknown, nuclear receptor (NR) ligands present in complex matrices. We explored the possibility to use NR-based affinity columns to characterize the presence of bioactive molecules in environmental complex mixtures. Estrogen receptor α (ERα)-based affinity columns were used to trap and purify estrogenic substances present in surface sediment samples collected in a French river under mixed anthropogenic pressure. We combined biological, biochemical and analytical approaches to characterize the structure of ligands retained on columns and demonstrate the presence of known active molecules such as bisphenol A and octylphenol, but also of unexpected ERα ligands (n-butylparaben, hydroxyl-methyl-benzofuranone). High resolution mass spectrometry results demonstrate that ERα affinity columns can be used for the isolation, purification and identification of known as well as unknown estrogenic contaminants present in complex matrices.
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Affiliation(s)
- Adeline Jondeau-Cabaton
- INRA, UMR 1331 TOXALIM (Research Center in Food Toxicology), Xenobiotic Metabolism Team, 180 Chemin de Tournefeuille, 31027 Toulouse, France
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12
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Chen M, Tang R, Fu G, Xu B, Zhu P, Qiao S, Chen X, Xu B, Qin Y, Lu C, Hang B, Xia Y, Wang X. Association of exposure to phenols and idiopathic male infertility. JOURNAL OF HAZARDOUS MATERIALS 2013; 250-251:115-121. [PMID: 23435201 DOI: 10.1016/j.jhazmat.2013.01.061] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 01/22/2013] [Accepted: 01/25/2013] [Indexed: 05/27/2023]
Abstract
Widespread human exposure to phenols has been documented recently, and some phenols which are potential endocrine disruptors have demonstrated adverse effects on male reproduction in animal and in vitro studies. However, implications about exposure to phenols and male infertility are scarce in humans. Case-control study of 877 idiopathic infertile men and 713 fertile controls was conducted. Urinary levels of bisphenol A, benzophenone-3, pentachlorophenol, triclosan, 4-tert-octylphenol (4-t-OP), 4-n-octylphenol (4-n-OP) and 4-n-nonylphenol (4-n-NP) and semen parameters were measured. After multivariate adjustment, we found 4-t-OP, 4-n-OP and 4-n-NP exposure was associated with idiopathic male infertility (p-value for trend: <0.0001, 0.014 and 0.001, respectively). Aside from these associations, 4-t-OP and 4-n-NP exposure was also associated with idiopathic male infertility with abnormal semen parameters. Moreover, we observed significant associations between sum alkylphenols (APs) exposure and idiopathic male infertility. There were no relationships between exposure to other phenols and idiopathic male infertility in the present study. Our study provides the first evidence that exposure to APs (4-t-OP, 4-n-OP and 4-n-NP) is associated with idiopathic male infertility.
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Affiliation(s)
- Minjian Chen
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210029, China
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13
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Chakraborty TR, Alicea E, Chakraborty S. Relationships between urinary biomarkers of phytoestrogens, phthalates, phenols, and pubertal stages in girls. ADOLESCENT HEALTH MEDICINE AND THERAPEUTICS 2012; 3:17-26. [PMID: 24600283 PMCID: PMC3915890 DOI: 10.2147/ahmt.s15947] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Phytoestrogens, phthalates, and phenols are estrogen-disrupting chemicals that have a pronounced effect at puberty. They are exogenous chemicals that are either plant-derived or man-made, and can alter the functions of the endocrine system and cause various health defects by interfering with the synthesis, metabolism, binding, or cellular responses of natural estrogens. Phytoestrogens, phthalates, and phenols are some of the potent estrogens detectable in urine. Phytoestrogens are plant-derived xenestrogens found in a wide variety of food products, like soy-based food, beverages, several fruits, and vegetables. Exposure to phytoestrogens can delay breast development and further lead to precocious puberty. The effect of phytoestrogens is mediated through estrogen receptors α and β or by binding with early immediate genes, such as jun and fos. Phthalates are multifunctional synthetic chemicals used in plastics, polyvinyl chloride products, cosmetics, hair spray, and children’s toys. Phthalates have been shown to cause defeminization, thelarche, precocious puberty, and an increase in breast and pubic hair in pubertal girls. However, reports are also available that show no association of phthalates with precocious puberty in girls. Phthalates can act through a receptor-mediated signaling pathway or affect the production of luteinizing hormone and follicle-stimulating hormone that has a direct effect on estrogen formation. Phenols like bisphenol A are industrial chemicals used mainly in the manufacture of polycarbonates and plastic materials. Bisphenol A has been shown to cause precocious puberty and earlier menarche in pubertal girls. Reports suggest that the neurotoxic effect of bisphenol A can be mediated either by competing with estradiol for binding with estrogen receptors or via the ERK/NK-kappa or ERRγ pathway. This review demonstrates the effects of phytoestrogens, phthalates, and phenols on the development of girls during puberty.
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Affiliation(s)
- Tandra R Chakraborty
- Department of Biology, Adelphi University, One South Avenue, Garden City, New York, NY, USA
| | - Eilliut Alicea
- Department of Biology, Adelphi University, One South Avenue, Garden City, New York, NY, USA
| | - Sanjoy Chakraborty
- Department of Biological Sciences, New York City College of Technology, New York, NY, USA
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14
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Chang LL, Wun WSA, Wang PS. Effects of nonylphenol on aldosterone release from rat zona glomerulosa cells. Chem Biol Interact 2011; 195:11-7. [PMID: 22001352 DOI: 10.1016/j.cbi.2011.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Revised: 09/25/2011] [Accepted: 09/27/2011] [Indexed: 11/30/2022]
Abstract
Alkylphenol ethoxylate, which consists of approximately 80% nonylphenol ethoxylate (NPE), is a major nonionic surfactant. Nonylphenol (NP), the primary degradation product of NPE, has been reported to interfere with reproduction in fish, reptiles, and mammals by inducing cell death in the gonads and by affecting other reproductive parameters. However, the effects of NP on rat adrenal zona glomerulosa cells (ZG) and the underlying mechanisms remain unclear. In this study, we explored the effects of NP on aldosterone release. ZG cells were incubated with NP in the presence or absence of the secretagogues angiotensin II (ANG II), potassium, 8-Br-cAMP, 25-OH-cholesterol, corticosterone or cyclopiazonic acid (CPA). After performing radioimmunoassay (RIA) and Western blot analysis, we found that (1) NP stimulated aldosterone release in cells induced by ANG II, KCl, 8-Br-cAMP, 25-OH-cholesterol, corticosterone, and CPA; (2) NP triggered the release of higher amounts of pregnenolone in cells treated with vehicle and 25-OH-cholesterol+trilostane than in cells treated with other compounds; and (3) the stimulatory effect of NP seemed to be mediated through steroidogenic acute regulatory protein (StAR) and aldosterone synthase activity. These observations suggest that the effects of NP are mediated via increased free Ca(2+) in the cytoplasm.
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Affiliation(s)
- Ling-Ling Chang
- Department of Chemical and Materials Engineering, Chinese Culture University, Taipei, Taiwan, ROC
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15
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Graham LA, Shaw IC. Does the oestrogen receptor encourage oestrogenicity in environmental pollutants? The case of 4-nonylphenol. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2011; 22:329-350. [PMID: 21598197 DOI: 10.1080/1062936x.2011.569899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A computer-aided docking study was conducted to explore in detail the binding interactions between the structurally unlikely environmental oestrogen 4-nonylphenol (4NP) and three of its metabolites with the human oestrogen receptor alpha (hERα). Docking was done within the Schrodinger Suite 2008 using both a conventional rigid receptor with flexible ligand and the induced-fit docking protocol. Induced-fit docking allows side-chain and backbone movement in the receptor to accommodate the ligand. This study has revealed unconventional interactions between the ligands and the hERα binding pocket that could explain the observed oestrogen-like behaviour of 4NP and suggests some of the metabolites of 4NP may also be oestrogenic.
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Affiliation(s)
- L A Graham
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
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Behavioral impairment and oxidative damage induced by chronic application of nonylphenol. Int J Mol Sci 2010; 12:114-27. [PMID: 21339980 PMCID: PMC3039946 DOI: 10.3390/ijms12010114] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 12/20/2010] [Accepted: 12/28/2010] [Indexed: 11/25/2022] Open
Abstract
Nonylphenol (NP) is a degradation product of nonylphenol polyethoxylates, which are widely used in the production of industrial and consumer surfactants. The aim of the present study was to evaluate the effect of NP on the antioxidant capacity and cognitive ability of mice. NP was given orally by gavages at doses of 0, 50, 100, and 200 mg kg−1 d−1 for 90 days. The results showed that NP significantly decreased the activity of superoxide dismutases (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) and at the same time increased malondialdehyde (MDA) levels in mice brains. Exploration, memory function and ability to learn a novel task were significantly decreased in NP fed mice. These results indicate that chronic high dose of NP exposure has the potential to generate oxidative stress and induce the cognitive impairment in male mice.
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Deng P, Zhong D, Nan F, Liu S, Li D, Yuan T, Chen X, Zheng J. Evidence for the bioactivation of 4-nonylphenol to quinone methide and ortho-benzoquinone metabolites in human liver microsomes. Chem Res Toxicol 2010; 23:1617-28. [PMID: 20843008 DOI: 10.1021/tx100223h] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
4-Nonylphenol (4-NP) is a well-known toxic environmental contaminant. The major objective of the present study was to identify reactive metabolites of 4-NP. Following incubations of 4-NP with NADPH- and GSH-supplemented human liver microsomes, 6 GSH conjugates, along with 19 oxidized metabolites, were detected by UPLC/Q-TOF mass spectrometry utilizing the mass defect filter method. Several authentic key metabolite standards were chemically synthesized for structural identification. Three GSH conjugates were found to derive from quinone methide intermediates, and the other three resulted from ortho-benzoquinone intermediates. Conjugation of the quinone methides with GSH produced benzylic-orientated GSH conjugates by 1,6-addition, while the reaction of the ortho-benzoquinone intermediates offered aromatic-orientated GSH conjugates. The conversion of 4-NP to the quinone methides and ortho-hydroquinones required cytochromes P450, specifically CYPs1A2, 2C19, 2D6, 2E1, and 3A4, while the oxidation of ortho-benzohydroquinones to the corresponding benzoquinones was apparently independent of microsomal enzymes. The ortho-benzoquinone derived from 4-NP was isomerized to the corresponding hydroxyquinone methide, and the former dominated the latter at a rate of approximately 20:1. The findings of the quinone methide and benzoquinone metabolites intensified the concern on the impact of 4-NP exposure on human health.
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Affiliation(s)
- Pan Deng
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
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18
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Rózalska S, Szewczyk R, Długoński J. Biodegradation of 4-n-nonylphenol by the non-ligninolytic filamentous fungus Gliocephalotrichum simplex: a proposal of a metabolic pathway. JOURNAL OF HAZARDOUS MATERIALS 2010; 180:323-331. [PMID: 20447765 DOI: 10.1016/j.jhazmat.2010.04.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 04/09/2010] [Accepted: 04/09/2010] [Indexed: 05/29/2023]
Abstract
4-Nonylphenols (NPs) are endocrine disrupting compounds (EDCs) which are known to interfere with the endocrine system of humans and animals. The aim of this study was to test the ability of non-ligninolytic filamentous fungus Gliocephalotrichum simplex to biodegrade 4-n-NP. The results revealed that during the first 24h of incubation, 4-n-NP at the concentration of 50 mg L(-1) was eliminated from the culture medium by 88%, whereas at the concentration of 100 mg L(-1) by 50%. In this paper, glucose utilization as a co-substrate during toxic compound degradation was also shown. It was found that the presence of 4-n-NP caused sugar metabolism retardation and this inhibition was dependent on NP concentration. The qualitative GC-MS analysis showed the presence of products of G. simplex 4-n-NP biodegradation. We proposed the metabolic pathway of 4-n-NP biodegradation, which is based on subsequent C1 removals from the alkyl chain followed by the aromatic ring cleavage. In further experiments with 4-n-NP [ring-(14)C(U)] we proved aromatic ring cleavage occurrence. After 72 h of incubation the evolution of (14)CO(2) was observed and the mineralization efficiency was on the level of 29%. The results suggest the existence of a novel mechanism of 4-n-NP degradation in fungi.
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Affiliation(s)
- Sylwia Rózalska
- Department of Industrial Microbiology and Biotechnology, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland
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Fumeaux R, Menozzi-Smarrito C, Stalmach A, Munari C, Kraehenbuehl K, Steiling H, Crozier A, Williamson G, Barron D. First synthesis, characterization, and evidence for the presence of hydroxycinnamic acid sulfate and glucuronide conjugates in human biological fluids as a result of coffee consumption. Org Biomol Chem 2010; 8:5199-211. [DOI: 10.1039/c0ob00137f] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Quantification of the influence of extracellular laccase and intracellular reactions on the isomer-specific biotransformation of the xenoestrogen technical nonylphenol by the aquatic hyphomycete Clavariopsis aquatica. Appl Environ Microbiol 2009; 75:4398-409. [PMID: 19429559 DOI: 10.1128/aem.00139-09] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aquatic hyphomycete Clavariopsis aquatica was used to quantify the effects of extracellular laccase and intracellular reactions on the isomer-specific biotransformation of technical nonylphenol (t-NP). In laccase-producing cultures, maximal removal rates of t-NP and the isomer 4-(1-ethyl-1,4-dimethylpentyl)phenol (NP112) were about 1.6- and 2.4-fold higher, respectively, than in laccase-lacking cultures. The selective suppression of either laccase or intracellular reactions resulted in essentially comparable maximal removal rates for both compounds. Evidence for an unspecific oxidation of t-NP isomers was consistently obtained from laccase-expressing fungal cultures when intracellular biotransformation was suppressed and from reaction mixtures containing isolated laccase. This observation contrasts with the selective degradation of t-NP isomers by bacteria and should prevent the enrichment of highly estrogenic isomers in remaining t-NP. In contrast with laccase reactions, intracellular fungal biotransformation caused a significant shift in the isomeric composition of remaining t-NP. As a result, certain t-NP constituents related to more estrogenic isomers were less efficiently degraded than others. In contrast to bacterial degradation via ipso-hydroxylation, the substitution pattern of the quaternary alpha-carbon of t-NP isomers does not seem to be very important for intracellular transformation in C. aquatica. As-yet-unknown intracellular enzymes are obviously induced by nonylphenols. Mass spectral data of the metabolites resulting from the intracellular oxidation of t-NP, NP112, and 4-(1-ethyl-1,3-dimethylpentyl)phenol indicate nonyl chain hydroxylation, further oxidation into keto or aldehyde compounds, and the subsequent formation of carboxylic acid derivatives. Further metabolites suggest nonyl chain desaturation and methylation of carboxylic acids. The phenolic moieties of the nonylphenols remained unchanged.
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Elevation of inducible nitric oxide synthase and cyclooxygenase-2 expression in the mouse brain after chronic nonylphenol exposure. Int J Mol Sci 2008; 9:1977-88. [PMID: 19325730 PMCID: PMC2635611 DOI: 10.3390/ijms9101977] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2008] [Revised: 10/09/2008] [Accepted: 10/13/2008] [Indexed: 02/06/2023] Open
Abstract
The present study was performed to investigate the effects of chronic administration of nonylphenol (NP) on the expression of inflammation-related genes in the brains of mice. NP was given orally by gavages at 0, 50, 100, and 200 mg/kg/d. The expression of inflammatory enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), was evaluated by immunohistochemistry and immunoblotting assays. The nitric oxide (NO) level and nitric oxide synthase (NOS) activity were also measured by biochemical analyses. The results showed that NP at a high dose (200 mg/kg/d) significantly increased the expression of iNOS and COX-2 in both the hippocampus and cortex. In parallel with the increase in iNOS expression, the NO level was significantly greater at the dose of 200 mg/kg/d, compared to the control. The activity of NOS was also increased in the brain of mice at the dose of 100 and 200 mg/kg/d. These findings demonstrate that NP may have the potential to induce the chronic inflammation or cause neurotoxicity in the mouse brain.
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22
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Mao Z, Zheng YL, Zhang YQ, Han BP, Chen LT, Li J, Li F, Shan Q. Chronic application of nonylphenol-induced apoptosis via suppression of bcl-2 transcription and up-regulation of active caspase-3 in mouse brain. Neurosci Lett 2008; 439:147-52. [PMID: 18514416 DOI: 10.1016/j.neulet.2008.05.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Revised: 04/25/2008] [Accepted: 05/03/2008] [Indexed: 10/22/2022]
Abstract
Nonylphenol (NP) is an endocrine disruptor, which has been reported to have adverse effects on reproductive and immune systems. However, the influence of NP on the central nervous system (CNS) has not been extensively explored. The present study was performed to investigate the effects of chronic administration of NP on the apoptosis-related protein expression in mouse brain by in situ hybridization, RT-PCR and immunoblotting assays. The expression of bcl-2 mRNA was down-regulated by NP at the doses of 100 and 200mg/(kg day) (p<0.05), whereas the expression of bax mRNA was not affected in NP treated mice (p>0.05). Furthermore, as the main executor of apoptosis, the expression of active caspase-3 was up-regulated by 100 and 200mg/(kg day) NP (p<0.01), which is in accord with the results of terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL) (p<0.05). These results suggest that chronic application of NP could sensitize the mice brain to apoptosis.
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Affiliation(s)
- Zhen Mao
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221008, Jiangsu Province, PR China
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23
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Ye X, Bishop AM, Needham LL, Calafat AM. Identification of metabolites of 4-nonylphenol isomer 4-(3',6'-dimethyl-3'-heptyl) phenol by rat and human liver microsomes. Drug Metab Dispos 2007; 35:1269-74. [PMID: 17460028 DOI: 10.1124/dmd.107.015578] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nonylphenol (NP) has been widely used for more than 50 years in the synthesis of NP ethoxylates, which are important nonionic surfactants. NP is considered an endocrine disruptor based on in vitro and in vivo animal studies. However, the toxic effects of NP in humans are unknown. Information regarding the metabolic fate of 4-t-nonylphenol (4-tNP), a mixture of commercial NP branched isomers, in mammalian species is limited. This information is critical for the identification of adequate biomarkers of exposure to NP that could be used for exposure and risk assessment. We identified metabolites of one 4-tNP isomer, namely, 4-(3',6'-dimethyl-3'-heptyl) phenol (P363-NP), using rat and human liver microsomes. The P363-NP metabolites were extracted by on-line solid-phase extraction and then separated and detected using high-performance liquid chromatography/tandem mass spectrometry. Using the genuine standard, we unambiguously identified 4-(3',6'-dimethyl-3'-heptyl) catechol (P363-NC) as the main P363-NP metabolite when using human liver microsomes. Based on their chromatographic behavior and mass spectral fragmentation patterns, several other metabolites were tentatively identified, including a hydroxylated P363-NP with the alcohol functional group on the branched alkyl chain and its oxidative metabolite, a catechol with a hydroxylated alkyl side chain. Furthermore, the metabolite profile of P363-NP using rat and human enzymes was compared. Our findings suggest that P363-NC could be used as a biomarker to assess exposure to 4-tNP, although additional research to evaluate its suitability as a biomarker is warranted.
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Affiliation(s)
- Xiaoyun Ye
- Centers for Disease Control and Prevention, 4770 Buford Highway, Mailstop MS F53, Atlanta, GA 30341, USA
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24
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Gontier-Latonnelle K, Cravedi JP, Laurentie M, Perdu E, Lamothe V, Le Menn F, Bennetau-Pelissero C. Disposition of genistein in rainbow trout (Oncorhynchus mykiss) and siberian sturgeon (Acipenser baeri). Gen Comp Endocrinol 2007; 150:298-308. [PMID: 17097654 DOI: 10.1016/j.ygcen.2006.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 09/14/2006] [Accepted: 10/02/2006] [Indexed: 10/23/2022]
Abstract
Genistein (G) is a xenoestrogen from soy present in fish diet. In vivo, a 50-fold difference in sensitivity to genistein on vitellogenin (VTG) synthesis was found when comparing trout and sturgeon. This difference was not linked to the estrogen receptor affinity nor to the sensitivity of induction of the VTG pathway. The study was performed to check if differences in the G disposition in the two species could explain their difference of sensitivity to G. A pharmacokinetic analysis of radiolabeled G was performed to determine its bioavailability and metabolism in both species. G was used at levels corresponding to fish farm exposure. G plasma levels after chronic ingestion were found to be 15.6 times higher in sturgeon than in trout. Sturgeon primarily produces sulfate conjugates after G ingestion whereas trout mainly produces glucuronides. Sturgeon was able to excrete orobol glucuronide in bile. An important first pass effect was suggested in both species. No accumulation of G or its metabolites was observed in the two species. Trout muscles accounted only for 0.14 of radioactivity 48 h post-ingestion similarly to sturgeon. Trout viscera accounted for 15% of the radioactivity 48 h post-ingestion. In sturgeon, 48 h post-ingestion, viscera accounted for 21.5% of the radioactivity. These rates decreased rapidly thereafter. The study partly explains the difference in sensitivity to G, previously recorded between the two species. In addition, it shows that human exposure to G through farmed fish consumption is negligible.
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Affiliation(s)
- K Gontier-Latonnelle
- Unité Micronutriments, Reproduction, Santé (UMRS), ENITA de Bordeaux, 1, cours du Général de Gaulle 33175 Gradignan, France
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25
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McClusky LM, de Jager C, Bornman MS. Stage-Related Increase in the Proportion of Apoptotic Germ Cells and Altered Frequencies of Stages in the Spermatogenic Cycle Following Gestational, Lactational, and Direct Exposure of Male Rats to p-Nonylphenol. Toxicol Sci 2006; 95:249-56. [PMID: 17065434 DOI: 10.1093/toxsci/kfl141] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The cumulative effects of environmental toxicants, for example, the alkylphenol, para-nonylphenol (p-NP) are of concern. Our previous study showed that p-NP reduced several testicular morphometric parameters, including sperm counts. The present study reexamined material collected in that study to determine the mechanistic basis of p-NP action on spermatogenic development in the offspring. Seven-day pregnant Sprague-Dawley rats were treated with vehicle or 100 or 250 mg/kg p-NP through gestation, lactation and afterward directly to all male offspring until 10 weeks of age. Both doses of p-NP significantly (P < 0.02) increased the number of germ cells with in situ end-labeled fragmented DNA (TUNEL positive) by 1.9-fold and 1.7-fold, respectively, and specifically in stages XII-XIV and I-III. TUNEL-labeling was, however, selective, and excluded labeling of basal cells with apoptotic morphology. Cleaved caspase-3 immunohistochemistry strongly labeled basal cells (spermatogonia and early spermatocytes) with condensed marginated chromatin but not degenerate germ cells lacking definitive nuclear material found throughout the epithelium. Only the caspase index (ratio of number of caspase positive to number of degenerate cells) of the 100-mg/kg p-NP group was significantly (p < 0.05) threefold greater than controls. Whereas both doses and either 250 or 100 mg/kg treatment alone significantly (p < 0.002) reduced the frequencies (duration) of stages I-III, VII-VIII, and late VIII-IX (spermiating and recently spermiated tubules), respectively, both doses significantly (p < 0.002) increased the frequencies of stages IV-VI and all stages containing late-stage spermatocytes (XII-XIII) and meiotic cell divisions (XIV). Thus, p-NP, an environmentally persistent xenoestrogen, insidiously alters the spermatogenic cycle and spermatogenic process in male offspring.
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Affiliation(s)
- L M McClusky
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, P.O. Box 2034, Pretoria 0001, South Africa.
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26
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Corvini PFX, Schäffer A, Schlosser D. Microbial degradation of nonylphenol and other alkylphenols—our evolving view. Appl Microbiol Biotechnol 2006; 72:223-43. [PMID: 16826376 DOI: 10.1007/s00253-006-0476-5] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 04/11/2006] [Accepted: 04/19/2006] [Indexed: 10/24/2022]
Abstract
Because the endocrine disrupting effects of nonylphenol (NP) and octylphenol became evident, the degradation of long-chain alkylphenols (AP) by microorganisms was intensively studied. Most NP-degrading bacteria belong to the sphingomonads and closely related genera, while NP metabolism is not restricted to defined fungal taxa. Growth on NP and its mineralization was demonstrated for bacterial isolates, whereas ultimate degradation by fungi still remains unclear. While both bacterial and fungal degradation of short-chain AP, such as cresols, and the bacterial degradation of long-chain branched AP involves aromatic ring hydroxylation, alkyl chain oxidation and the formation of phenolic polymers seem to be preferential elimination pathways of long-chain branched AP in fungi, whereby both intracellular and extracellular oxidative enzymes may be involved. The degradation of NP by sphingomonads does not proceed via the common degradation mechanisms reported for short-chain AP, rather, via an unusual ipso-substitution mechanism. This fact underlies the peculiarity of long-chain AP such as NP isomers, which possess highly branched alkyl groups mostly containing a quaternary alpha-carbon. In addition to physicochemical parameters influencing degradation rates, this structural characteristic confers to branched isomers of NP a biodegradability different to that of the widely used linear isomer of NP. Potential biotechnological applications for the removal of AP from contaminated media and the difficulties of analysis and application inherent to the hydrophobic NP, in particular, are also discussed. The combination of bacteria and fungi, attacking NP at both the phenolic and alkylic moiety, represents a promising perspective.
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Affiliation(s)
- P F X Corvini
- Department of Environmental Research, RWTH Aachen University, 52074, Aachen, Germany
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27
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Daidoji T, Ozawa M, Sakamoto H, Sako T, Inoue H, Kurihara R, Hashimoto S, Yokota H. SLOW ELIMINATION OF NONYLPHENOL FROM RAT INTESTINE. Drug Metab Dispos 2005; 34:184-90. [PMID: 16243956 DOI: 10.1124/dmd.105.007229] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nonylphenol, a possible endocrine disrupter, tends to persist in rat liver tissue after detoxification as a glucuronide conjugate by UDP-glucuronosyltransferase 2B1 expressed in the liver. In the intestine, however, the metabolism and dynamics of nonylphenol remain to be elucidated. The objectives of this study were to clarify the metabolism and excretion of nonylphenol having a long alkyl chain in the first barrier intestine and to estimate whether the nonylphenol alkyl chain governs the speed of excretion from intestinal tissue. Organ tissue glucuronidation activity toward alkylphenols (C2, C9) was investigated using microsomes prepared from intestinal tissue. To elucidate the elimination pathway of alkylphenols (C2, C4, C6, C9), a perfusion study was conducted on everted intestine. After oral administration (5 mg) of alkylphenols (C2, C9) to rats, gastrointestinal contents and related organ tissues (gastrointestinal tissue, liver, and kidney), blood, and urine were analyzed for alkylphenols (C2, C9) and glucuronides. The intestine showed strong glucuronidation activity toward alkylphenols (C2, C9). In everted intestinal assay, nonylphenol was glucuronidated within the intestinal wall, as was the case for other alkylphenols (C2, C4, C6), but nonylphenol-glucuronide was not excreted from intestinal tissue. Orally administered nonylphenol remained for long periods in gastrointestinal tissue as both the parent compound and glucuronide. The present study confirmed that intestinal tissue possesses an alkylphenol elimination system using UDP-glucuronosyltransferase; however, this system is impaired by the marginal transport of alkylphenol-glucuronide possessing long alkyl chain, such as nonylphenol.
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Affiliation(s)
- Tomo Daidoji
- Department of Veterinary Biochemistry, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069, Japan
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Calafat AM, Kuklenyik Z, Reidy JA, Caudill SP, Ekong J, Needham LL. Urinary concentrations of bisphenol A and 4-nonylphenol in a human reference population. ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:391-5. [PMID: 15811827 PMCID: PMC1278476 DOI: 10.1289/ehp.7534] [Citation(s) in RCA: 743] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 12/20/2004] [Indexed: 05/18/2023]
Abstract
Bisphenol A (BPA) is used to manufacture polycarbonate plastic and epoxy resins, which are used in baby bottles, as protective coatings on food containers, and for composites and sealants in dentistry. 4-Nonylphenol (NP) is used to make nonylphenol ethoxylates, nonionic surfactants applied as emulsifying, wetting, dispersing, or stabilizing agents in industrial, agricultural, and domestic consumer products. The potential for human exposure to BPA and NP is high because of their widespread use. We measured BPA and NP in archived urine samples from a reference population of 394 adults in the United States using isotope-dilution gas chromatography/mass spectrometry. The concentration ranges of BPA and NP were similar to those observed in other human populations. BPA was detected in 95% of the samples examined at concentrations > or = 0.1 microg/L urine; the geometric mean and median concentrations were 1.33 microg/L (1.36 microg/g creatinine) and 1.28 microg/L (1.32 microg/g creatinine), respectively; the 95th percentile concentration was 5.18 microg/L (7.95 microg/g creatinine). NP was detected in 51% of the samples examined > or = 0.1 microg/L. The median and 95th percentile concentrations were < 0.1 microg/L and 1.57 microg/L (1.39 microg/g creatinine), respectively. The frequent detection of BPA suggests widespread exposure to this compound in residents of the United States. The lower frequency of detection of NP than of BPA could be explained by a lower exposure of humans to NP, by different pharmacokinetic factors (i.e., absorption, distribution, metabolism, elimination), by the fact that 4-n-nonylphenol--the measured NP isomer--represents a small percentage of the NP used in commercial mixtures, or a combination of all of the above. Additional research is needed to determine the best urinary biomarker(s) to assess exposure to NP. Despite the sample population's nonrepresentativeness of the U.S. population (although sample weights were used to improve the extent to which the results represent the U.S. population) and relatively small size, this study provides the first reference range of human internal dose levels of BPA and NP in a demographically diverse human population.
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Affiliation(s)
- Antonia M Calafat
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA.
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Ross AB, Aman P, Kamal-Eldin A. Identification of cereal alkylresorcinol metabolites in human urine-potential biomarkers of wholegrain wheat and rye intake. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 809:125-30. [PMID: 15282102 DOI: 10.1016/j.jchromb.2004.06.015] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2004] [Revised: 06/03/2004] [Accepted: 06/10/2004] [Indexed: 11/24/2022]
Abstract
Alkylresorcinols, phenolic lipids present in high amounts in wholegrain wheat and rye, are of interest as potential biomarkers of the intake of these cereals. Alkylresorcinols are known to be absorbed by humans and animals, but little is known about their metabolism or resulting metabolites. A preliminary human study was carried out to identify alkylresorcinol metabolites in human urine. Urine samples, collected before and after a wheat-bran based meal, were deconjugated with beta-glucuronidase/sulphatase and then extracted with ethyl acetate. Extracts were separated by thin-layer chromatography, and fractions containing alkylresorcinols and possible metabolites were identified by retention on the plate compared to standard compounds, and staining with fast blue B. These fractions were further analysed by gas chromatography-mass spectrometry. Deconjugated human urine after the wheat-bran based meal contained two alkylresorcinol metabolites, 3,5-dihydroxybenzoic acid and 3-(3,5-dihydroxyphenyl)-1-propanoic acid, as well as smaller amounts of unchanged alkylresorcinols, confirming the hypothesis that alkylresorcinols are metabolised in humans via beta-oxidation of their alkyl chain.
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Affiliation(s)
- Alastair B Ross
- Department of Food Science, Swedish University of Agricultural Sciences (SLU), P.O. Box 7051, S-750 07 Uppsala, Sweden.
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Ross AB, Kamal-Eldin A, Aman P. Dietary alkylresorcinols: absorption, bioactivities, and possible use as biomarkers of whole-grain wheat- and rye-rich foods. Nutr Rev 2004; 62:81-95. [PMID: 15098855 DOI: 10.1111/j.1753-4887.2004.tb00029.x] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The biologic and chemical properties of alkylresorcinols (ARs) have been reviewed previously, but there has been relatively little research or focus on the importance of ARs in food and diet. ARs represent a significant proportion of the phytochemicals present in wheat and rye, in which they normally exist in concentrations between 300 and 1500 microg/g. ARs are concentrated in the bran fraction of these cereals, and are therefore a significant component of food products rich in whole grain wheat and rye but not in products containing only refined cereal flour. In this review, we discuss the presence of ARs in food, methods of analysis, their absorption and role in the diet in light of their in vitro bioactivities, and their possible use as biomarkers of whole-grain wheat and rye intake.
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Affiliation(s)
- Alastair B Ross
- Department of Food Science, Swedish University of Agricultural Sciences (SLU), P.O. Box 7051, SE-750 07 Uppsala, Sweden
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