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Duda-Chodak A, Tarko T. Possible Side Effects of Polyphenols and Their Interactions with Medicines. Molecules 2023; 28:molecules28062536. [PMID: 36985507 PMCID: PMC10058246 DOI: 10.3390/molecules28062536] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/05/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023] Open
Abstract
Polyphenols are an important component of plant-derived food with a wide spectrum of beneficial effects on human health. For many years, they have aroused great interest, especially due to their antioxidant properties, which are used in the prevention and treatment of many diseases. Unfortunately, as with any chemical substance, depending on the conditions, dose, and interactions with the environment, it is possible for polyphenols to also exert harmful effects. This review presents a comprehensive current state of the knowledge on the negative impact of polyphenols on human health, describing the possible side effects of polyphenol intake, especially in the form of supplements. The review begins with a brief overview of the physiological role of polyphenols and their potential use in disease prevention, followed by the harmful effects of polyphenols which are exerted in particular situations. The individual chapters discuss the consequences of polyphenols’ ability to block iron uptake, which in some subpopulations can be harmful, as well as the possible inhibition of digestive enzymes, inhibition of intestinal microbiota, interactions of polyphenolic compounds with drugs, and impact on hormonal balance. Finally, the prooxidative activity of polyphenols as well as their mutagenic, carcinogenic, and genotoxic effects are presented. According to the authors, there is a need to raise public awareness about the possible side effects of polyphenols supplementation, especially in the case of vulnerable subpopulations.
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Phytoestrogens and Health Effects. Nutrients 2023; 15:nu15020317. [PMID: 36678189 PMCID: PMC9864699 DOI: 10.3390/nu15020317] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 12/31/2022] [Accepted: 01/03/2023] [Indexed: 01/10/2023] Open
Abstract
Phytoestrogens are literally estrogenic substances of plant origin. Although these substances are useful for plants in many aspects, their estrogenic properties are essentially relevant to their predators. As such, phytoestrogens can be considered to be substances potentially dedicated to plant-predator interaction. Therefore, it is not surprising to note that the word phytoestrogen comes from the early discovery of estrogenic effects in grazing animals and humans. Here, several compounds whose activities have been discovered at nutritional concentrations in animals and humans are examined. The substances analyzed belong to several chemical families, i.e., the flavanones, the coumestans, the resorcylic acid lactones, the isoflavones, and the enterolignans. Following their definition and the evocation of their role in plants, their metabolic transformations and bioavailabilities are discussed. A point is then made regarding their health effects, which can either be beneficial or adverse depending on the subject studied, the sex, the age, and the physiological status. Toxicological information is given based on official data. The effects are first presented in humans. Animal models are evoked when no data are available in humans. The effects are presented with a constant reference to doses and plausible exposure.
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Di Dalmazi G, Giuliani C. Plant constituents and thyroid: A revision of the main phytochemicals that interfere with thyroid function. Food Chem Toxicol 2021; 152:112158. [PMID: 33789121 DOI: 10.1016/j.fct.2021.112158] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 03/22/2021] [Accepted: 03/24/2021] [Indexed: 01/06/2023]
Abstract
In the past few decades, there has been a lot of interest in plant constituents for their antioxidant, anti-inflammatory, anti-microbial and anti-proliferative properties. However, concerns have been raised on their potential toxic effects particularly when consumed at high dose. The anti-thyroid effects of some plant constituents have been known for some time. Indeed, epidemiological observations have shown the causal association between staple food based on brassicaceae or soybeans and the development of goiter and/or hypothyroidism. Herein, we review the main plant constituents that interfere with normal thyroid function such as cyanogenic glucosides, polyphenols, phenolic acids, and alkaloids. In detail, we summarize the in vitro and in vivo studies present in the literature, focusing on the compounds that are more abundant in foods or that are available as dietary supplements. We highlight the mechanism of action of these compounds on thyroid cells by giving a particular emphasis to the experimental studies that can be significant for human health. Furthermore, we reveal that the anti-thyroid effects of these plant constituents are clinically evident only when they are consumed in very large amounts or when their ingestion is associated with other conditions that impair thyroid function.
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Affiliation(s)
- Giulia Di Dalmazi
- Center for Advanced Studies and Technology (CAST) and Department of Medicine and Aging Science, University "G. d'Annunzio" of Chieti-Pescara, 66100, Chieti, Italy; Department of Medicine and Aging Science, Translational Medicine PhD Program, University "G. d'Annunzio" of Chieti-Pescara, 66100, Chieti, Italy.
| | - Cesidio Giuliani
- Center for Advanced Studies and Technology (CAST) and Department of Medicine and Aging Science, University "G. d'Annunzio" of Chieti-Pescara, 66100, Chieti, Italy.
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Messina M, Mejia SB, Cassidy A, Duncan A, Kurzer M, Nagato C, Ronis M, Rowland I, Sievenpiper J, Barnes S. Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data. Crit Rev Food Sci Nutr 2021; 62:5824-5885. [PMID: 33775173 DOI: 10.1080/10408398.2021.1895054] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.
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Affiliation(s)
- Mark Messina
- Department of Nutrition, Loma Linda University, Loma Linda, California, USA
| | - Sonia Blanco Mejia
- Department of Nutritional Sciences, University of Toronto, Toronto, Canada
| | - Aedin Cassidy
- Nutrition and Preventive Medicine, Queen's University, Belfast, Northern Ireland, UK
| | - Alison Duncan
- College of Biological Sciences, University of Guelph, Guelph, Canada
| | - Mindy Kurzer
- Department of Food Science and Nutrition, University of Minnesota, Minneapolis, Minnesota, USA
| | - Chisato Nagato
- Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Martin Ronis
- Health Sciences Center, Louisiana State University Health Sciences Center, Baton Rouge, New Orleans, USA
| | - Ian Rowland
- Human Nutrition, University of Reading, Reading, England, UK
| | | | - Stephen Barnes
- Department of Pharmacology and Toxicology, University of Alabama, Alabama, USA
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5
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Silva H. The Vascular Effects of Isolated Isoflavones-A Focus on the Determinants of Blood Pressure Regulation. BIOLOGY 2021; 10:49. [PMID: 33445531 PMCID: PMC7827317 DOI: 10.3390/biology10010049] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/27/2020] [Accepted: 01/02/2021] [Indexed: 02/07/2023]
Abstract
Isoflavones are phytoestrogen compounds with important biological activities, including improvement of cardiovascular health. This activity is most evident in populations with a high isoflavone dietary intake, essentially from soybean-based products. The major isoflavones known to display the most important cardiovascular effects are genistein, daidzein, glycitein, formononetin, and biochanin A, although the closely related metabolite equol is also relevant. Most clinical studies have been focused on the impact of dietary intake or supplementation with mixtures of compounds, with only a few addressing the effect of isolated compounds. This paper reviews the main actions of isolated isoflavones on the vasculature, with particular focus given to their effect on the determinants of blood pressure regulation. Isoflavones exert vasorelaxation due to a multitude of pathways in different vascular beds. They can act in the endothelium to potentiate the release of NO and endothelium-derived hyperpolarization factors. In the vascular smooth muscle, isoflavones modulate calcium and potassium channels, leading to hyperpolarization and relaxation. Some of these effects are influenced by the binding of isoflavones to estrogen receptors and to the inhibition of specific kinase enzymes. The vasorelaxation effects of isoflavones are mostly obtained with plasma concentrations in the micromolar range, which are only attained through supplementation. This paper highlights isolated isoflavones as potentially suitable alternatives to soy-based foodstuffs and supplements and which could enlarge the current therapeutic arsenal. Nonetheless, more studies are needed to better establish their safety profile and elect the most useful applications.
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Affiliation(s)
- Henrique Silva
- Informetrics Research Group, Ton Duc Thang University, Ho Chi Minh City 758307, Vietnam;
- Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City 758307, Vietnam
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6
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Ciccone L, Tonali N, Nencetti S, Orlandini E. Natural compounds as inhibitors of transthyretin amyloidosis and neuroprotective agents: analysis of structural data for future drug design. J Enzyme Inhib Med Chem 2020; 35:1145-1162. [PMID: 32419519 PMCID: PMC7301710 DOI: 10.1080/14756366.2020.1760262] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 12/13/2022] Open
Abstract
Natural compounds, such as plant and fruit extracts have shown neuroprotective effect against neurodegenerative diseases. It has been reported that several natural compounds binding to transthyretin (TTR) can be useful in amyloidosis prevention. TTR is a transporter protein that under physiological condition carries thyroxine (T4) and retinol in plasma and in cerebrospinal fluid (CSF); it also has a neuroprotective role against Alzheimer's disease (AD). However, TTR also is an amyloidogenic protein responsible for familial amyloid polyneuropathy (FAP) and familial amyloid cardiomyopathy (FAC). The TTR amyloidogenic potential is speeded up by several point mutations. One therapeutic strategy against TTR amyloidosis is the stabilisation of the native tetramer by natural compounds and small molecules. In this review, we examine the natural products that, starting from 2012 to present, have been studied as a stabiliser of TTR tetramer. In particular, we discussed the chemical and structural features which will be helpful for future drug design of new TTR stabilisers.
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Affiliation(s)
- Lidia Ciccone
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | - Nicoló Tonali
- CNRS, Université Paris-Saclay, Châtenay-Malabry, France
| | - Susanna Nencetti
- Department of Pharmacy, University of Pisa, Pisa, Italy
- Interdepartmental Research Centre “Nutraceuticals and Food for Health (NUTRAFOOD), University of Pisa, Pisa, Italy
| | - Elisabetta Orlandini
- Department of Earth Sciences, University of Pisa, Pisa, Italy
- Research Center “E. Piaggio”, University of Pisa, Pisa, Italy
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Chokeberry anthocyanins and their metabolites ability to cross the blood-cerebrospinal fluid barrier. Food Chem 2020; 346:128730. [PMID: 33293147 DOI: 10.1016/j.foodchem.2020.128730] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 11/19/2020] [Accepted: 11/21/2020] [Indexed: 12/12/2022]
Abstract
The aim of this study was to determine whether anthocyanins and their phase II metabolites permeate the blood-cerebrospinal fluid barrier (B-CSF-B) of sheep and to profile these compounds in sheep biofluids after chokeberry intraruminal administration. Anthocyanins were analyzed using micro-HPLC-MS/MS. After chokeberry administration, anthocyanins were absorbed and occurred in body fluids mainly in the form of methylated, glucuronidated, and sulfated derivatives (in total, 21 derivatives were identified). The study showed that anthocyanins penetrated the B-CSF-B and their change in profile and concentration in the cerebrospinal fluid (CSF) resulted from fluctuations in concentrations of these compounds in blood plasma, although the presence of various cyanidin derivatives in CSF also depended on their chemical structure. The biological fate of chokeberry anthocyanins, from absorption into blood to penetration into CSF, was tracked to facilitate the design of further experimental procedures to determine the biological properties of these compounds, including potentially neuroprotective activities.
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Platosz N, Bączek N, Topolska J, Szawara-Nowak D, Misztal T, Wiczkowski W. The Blood-Cerebrospinal Fluid Barrier Is Selective for Red Cabbage Anthocyanins and Their Metabolites. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:8274-8285. [PMID: 32640787 DOI: 10.1021/acs.jafc.0c03170] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The study aim was to determine whether strongly bioactive hydrophilic red cabbage anthocyanins possess the ability to cross the blood-cerebrospinal fluid barrier (blood-CSF barrier) and whether there is a selectivity of this barrier toward these compounds. To fulfill objectives, red cabbage preparation, containing nonacylated and acylated anthocyanins, was administered to 16 sheep with implanted cannulas into the brain third ventricle, and next, within 10 h, blood, urine, and the cerebrospinal fluid (CSF) were collected and analyzed with HPLC-MS/MS. Though, in blood plasma and urine after red cabbage intake, both, acylated and nonacylated anthocyanins and their metabolites occurred, but only nonacylated derivatives were present in the CSF, and their changes in the profile and concentration in the CSF resulted from the fluctuation of these pigments' concentration and profile in blood, their different abilities to permeate via the blood-CSF barrier, and their transformations in this barrier. Results indicate that the blood-CSF barrier is selective for red cabbage anthocyanins.
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Affiliation(s)
- Natalia Platosz
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences in Olsztyn, Tuwima 10 Str., 10-748 Olsztyn, Poland
| | - Natalia Bączek
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences in Olsztyn, Tuwima 10 Str., 10-748 Olsztyn, Poland
| | - Joanna Topolska
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences in Olsztyn, Tuwima 10 Str., 10-748 Olsztyn, Poland
| | - Dorota Szawara-Nowak
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences in Olsztyn, Tuwima 10 Str., 10-748 Olsztyn, Poland
| | - Tomasz Misztal
- The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabl̷onna, Poland
| | - Wieslaw Wiczkowski
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences in Olsztyn, Tuwima 10 Str., 10-748 Olsztyn, Poland
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Chin KY, Pang KL. Skeletal Effects of Early-Life Exposure to Soy Isoflavones-A Review of Evidence From Rodent Models. Front Pediatr 2020; 8:563. [PMID: 33072660 PMCID: PMC7533582 DOI: 10.3389/fped.2020.00563] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 08/03/2020] [Indexed: 12/14/2022] Open
Abstract
Isoflavones are dietary phytoestrogens commonly found in soy-based products. The widespread presence of isoflavones in soy infant formula and breast milk may have long-lasting effects on the development of sex hormone-sensitive organs like the skeleton. Animal early-life programming models are suitable for testing the skeletal effects of pre- and neonatal exposure of soy isoflavones. This review aims to collate the impacts of early-life exposure of soy isoflavones as evidenced in animal models. The isoflavones previously studied include daidzein, genistein, or a combination of both. They were administered to rodent pups during the first few days postnatal, but prolonged exposure had also been studied. The skeletal effects were observed when the animals reached sexual maturity or after castration to induce bone loss. In general, neonatal exposure to soy isoflavones exerted beneficial effects on the skeletal system of female rodents, but the effects on male rodents seem to depend on the time of exposure and require further examinations. It might also protect the animals against bone loss due to ovariectomy at adulthood but not upon orchidectomy. The potential benefits of isoflavones on the skeletal system should be interpreted together with its non-skeletal effects in the assessment of its safety and impacts.
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Affiliation(s)
- Kok-Yong Chin
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.,State Key Laboratory of Oncogenes and Related Genes, Department of Urology, Renji-Med X Clinical Stem Cell Research Center, School of Medicine, Ren Ji Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Kok-Lun Pang
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
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Šošić-Jurjević B, Ajdžanović V, Filipović B, Severs W, Milošević V. Thyroid Mediation of the Isoflavone Effects on Osteoporotic Bone: The Endocrine Interference With a Beneficial Outcome. Front Endocrinol (Lausanne) 2019; 10:688. [PMID: 31681166 PMCID: PMC6798150 DOI: 10.3389/fendo.2019.00688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 09/23/2019] [Indexed: 01/11/2023] Open
Affiliation(s)
- Branka Šošić-Jurjević
- Department of Cytology, Institute for Biological Research “Siniša Stanković”, University of Belgrade, Belgrade, Serbia
| | - Vladimir Ajdžanović
- Department of Cytology, Institute for Biological Research “Siniša Stanković”, University of Belgrade, Belgrade, Serbia
| | - Branko Filipović
- Department of Cytology, Institute for Biological Research “Siniša Stanković”, University of Belgrade, Belgrade, Serbia
| | - Walter Severs
- College of Medicine, Pennsylvania State University, Hershey, PA, United States
| | - Verica Milošević
- Department of Cytology, Institute for Biological Research “Siniša Stanković”, University of Belgrade, Belgrade, Serbia
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Šošić-Jurjević B, Lütjohann D, Renko K, Filipović B, Radulović N, Ajdžanović V, Trifunović S, Nestorović N, Živanović J, Manojlović Stojanoski M, Kӧhrle J, Milošević V. The isoflavones genistein and daidzein increase hepatic concentration of thyroid hormones and affect cholesterol metabolism in middle-aged male rats. J Steroid Biochem Mol Biol 2019; 190:1-10. [PMID: 30885834 DOI: 10.1016/j.jsbmb.2019.03.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 03/06/2019] [Accepted: 03/13/2019] [Indexed: 01/05/2023]
Abstract
We examined whether isoflavones interfere with thyroid homeostasis, increase hepatic thyroid hormone concentrations and affect cholesterol metabolism in middle-aged (MA) male rats. Thirteen-month-old Wistar rats were injected subcutaneously with 35 mg/kg b.w./day of genistein, daidzein or vehicle (controls) for four weeks. Hepatic Dio1 gene expression was up-regulated by 70% (p < 0.001 for both) and Dio1 enzyme activity increased by 64% after genistein (p < 0.001) and 73% after daidzein treatment (p < 0.0001). Hepatic T3 was 75% higher (p < 0.05 for both), while T4 increased only after genistein treatment. Serum T4 concentrations were 31% lower in genistein- and 49% lower in dadzein-treated rats (p < 0.001 for both) compared with controls. Hepatic Cyp7a1 gene expression was up-regulated by 40% after genistein and 32% after daidzein treatment (p < 0.05 for both), in agreement with a 7α-hydroxycholesterol increase of 50% (p < 0.01) and 88% (p < 0.001), respectively. Serum 24- and 27-hydroxycholesterol were 30% lower (p < 0.05 for both), while only 24-hydroxycholesterol was decreased in the liver by 45% after genistein (p < 0.05) and 39% (p < 0.01) after dadzein treatment. Serum concentration of the cholesterol precursor desmosterol was 32% (p < 0.05) lower only after dadzein treatment alone, while both isoflavones elevated this parameter in the liver by 45% (p < 0.01). In conclusion, isoflavones increased T3 availability in the liver of MA males, despite decreasing serum T4. Hepatic increase of T3 possibly contributes to activation of the neutral pathway of cholesterol degradation into bile acids in the liver. While isoflavones obviously have the potential to trigger multiple mechanisms involved in cholesterol metabolism and oxysterol production, they failed to induce any hypocholesterolemic effect.
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Affiliation(s)
- B Šošić-Jurjević
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia.
| | - D Lütjohann
- Institut für Klinische Chemie und Klinische Pharmakologie, Universitätsklinikum Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany
| | - K Renko
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - B Filipović
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - N Radulović
- Department of Chemistry, Faculty of Science and Mathematics, University of Niš, Višegradska 33, 18000 Niš, Serbia
| | - V Ajdžanović
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - S Trifunović
- Institut für Klinische Chemie und Klinische Pharmakologie, Universitätsklinikum Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany
| | - N Nestorović
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - J Živanović
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - M Manojlović Stojanoski
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - J Kӧhrle
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - V Milošević
- Institute for Biological Research, "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
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Křížová L, Dadáková K, Kašparovská J, Kašparovský T. Isoflavones. Molecules 2019; 24:E1076. [PMID: 30893792 PMCID: PMC6470817 DOI: 10.3390/molecules24061076] [Citation(s) in RCA: 339] [Impact Index Per Article: 67.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 02/28/2019] [Accepted: 03/01/2019] [Indexed: 12/13/2022] Open
Abstract
Phytoestrogens are naturally occurring nonsteroidal phenolic plant compounds that, due to their molecular structure and size, resemble vertebrate steroids estrogens. This review is focused on plant flavonoids isoflavones, which are ranked among the most estrogenic compounds. The main dietary sources of isoflavones for humans are soybean and soybean products, which contain mainly daidzein and genistein. When they are consumed, they exert estrogenic and/or antiestrogenic effects. Isoflavones are considered chemoprotective and can be used as an alternative therapy for a wide range of hormonal disorders, including several cancer types, namely breast cancer and prostate cancer, cardiovascular diseases, osteoporosis, or menopausal symptoms. On the other hand, isoflavones may also be considered endocrine disruptors with possible negative influences on the state of health in a certain part of the population or on the environment. This review deals with isoflavone classification, structure, and occurrence, with their metabolism, biological, and health effects in humans and animals, and with their utilization and potential risks.
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Affiliation(s)
- Ludmila Křížová
- Department of Biochemistry, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.
| | - Kateřina Dadáková
- Department of Biochemistry, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.
| | - Jitka Kašparovská
- Department of Biochemistry, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.
| | - Tomáš Kašparovský
- Department of Biochemistry, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.
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Shaji D. Molecular docking studies of human MCT8 protein with soy isoflavones in Allan-Herndon-Dudley syndrome (AHDS). J Pharm Anal 2018; 8:318-323. [PMID: 30345146 PMCID: PMC6191963 DOI: 10.1016/j.jpha.2018.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 06/28/2018] [Accepted: 07/02/2018] [Indexed: 11/18/2022] Open
Abstract
Monocarboxylate transporter-8 (MCT8) is a specific thyroid hormone transporter, essential for the uptake of thyroid hormone into target tissues. Mutations in the MCT8 gene have been identified as the cause of Allan-Herndon-Dudley syndrome (AHDS). It has been reported that soy isoflavones influence thyroid hormone system and can interact with thyroid hormone transporter proteins. Therefore, the present study aimed to find out whether soy isoflavones (genistein, daidzein and glycitein) can be used as a natural inhibitor to target MCT8 in AHDS. Docking studies were performed for soy isoflavones in order to evaluate their binding affinity to MCT8 protein using AutoDock4 (version 4.2.6) and AutoDock Vina. After docking, the ligands were ranked according to their binding energy and the best lead compound was selected based on the least binding energy. The docking results indicated that daidzein possesses the lowest binding energy against MCT8. Moreover, it was found that the residues PRO-338, HIS-341, and GLU-348 were involved in hydrogen bond interactions with genistein and daidzein. This study suggests that daidzein is a promising natural inhibitor to target MCT8 in AHDS.
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Hüser S, Guth S, Joost HG, Soukup ST, Köhrle J, Kreienbrock L, Diel P, Lachenmeier DW, Eisenbrand G, Vollmer G, Nöthlings U, Marko D, Mally A, Grune T, Lehmann L, Steinberg P, Kulling SE. Effects of isoflavones on breast tissue and the thyroid hormone system in humans: a comprehensive safety evaluation. Arch Toxicol 2018; 92:2703-2748. [PMID: 30132047 PMCID: PMC6132702 DOI: 10.1007/s00204-018-2279-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/31/2018] [Indexed: 02/06/2023]
Abstract
Isoflavones are secondary plant constituents of certain foods and feeds such as soy, linseeds, and red clover. Furthermore, isoflavone-containing preparations are marketed as food supplements and so-called dietary food for special medical purposes to alleviate health complaints of peri- and postmenopausal women. Based on the bioactivity of isoflavones, especially their hormonal properties, there is an ongoing discussion regarding their potential adverse effects on human health. This review evaluates and summarises the evidence from interventional and observational studies addressing potential unintended effects of isoflavones on the female breast in healthy women as well as in breast cancer patients and on the thyroid hormone system. In addition, evidence from animal and in vitro studies considered relevant in this context was taken into account along with their strengths and limitations. Key factors influencing the biological effects of isoflavones, e.g., bioavailability, plasma and tissue concentrations, metabolism, temporality (pre- vs. postmenopausal women), and duration of isoflavone exposure, were also addressed. Final conclusions on the safety of isoflavones are guided by the aim of precautionary consumer protection.
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Affiliation(s)
- S Hüser
- Institute for Food Toxicology, Senate Commission on Food Safety, University of Veterinary Medicine Hannover, Hannover, Germany
| | - S Guth
- Institute for Food Toxicology, Senate Commission on Food Safety, University of Veterinary Medicine Hannover, Hannover, Germany
| | - H G Joost
- Department of Experimental Diabetology, German Institute of Human Nutrition (DIfE), Nuthetal, Germany
| | - S T Soukup
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Str. 9, 76131, Karlsruhe, Germany
| | - J Köhrle
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, CVK, Berlin, Germany
| | - L Kreienbrock
- Department of Biometry, Epidemiology and Information Processing, University of Veterinary Medicine Hannover, Hannover, Germany
| | - P Diel
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, Cologne, Germany
| | - D W Lachenmeier
- Chemisches und Veterinäruntersuchungsamt Karlsruhe, Karlsruhe, Germany
| | - G Eisenbrand
- Division of Food Chemistry and Toxicology, Molecular Nutrition, Department of Chemistry, Technische Universität Kaiserslautern, Kaiserslautern, Germany
| | - G Vollmer
- Department of Biology, Molecular Cell Physiology and Endocrinology, Technische Universität Dresden, Dresden, Germany
| | - U Nöthlings
- Department of Nutrition and Food Sciences, Nutritional Epidemiology, Rheinische Friedrich-Wilhelms University Bonn, Bonn, Germany
| | - D Marko
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - A Mally
- Department of Toxicology, University of Würzburg, Würzburg, Germany
| | - T Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition (DIfE), Nuthetal, Germany
| | - L Lehmann
- Department of Food Chemistry, Institute for Pharmacy and Food Chemistry, University of Würzburg, Würzburg, Germany
| | - P Steinberg
- Institute for Food Toxicology, University of Veterinary Medicine Hannover, Hannover, Germany
- Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Str. 9, 76131, Karlsruhe, Germany
| | - S E Kulling
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Str. 9, 76131, Karlsruhe, Germany.
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15
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Sathyapalan T, Köhrle J, Rijntjes E, Rigby AS, Dargham SR, Kilpatrick ES, Atkin SL. The Effect of High Dose Isoflavone Supplementation on Serum Reverse T 3 in Euthyroid Men With Type 2 Diabetes and Post-menopausal Women. Front Endocrinol (Lausanne) 2018; 9:698. [PMID: 30524380 PMCID: PMC6262038 DOI: 10.3389/fendo.2018.00698] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 11/06/2018] [Indexed: 11/21/2022] Open
Abstract
Background: The health benefits of soy are widely reported but there are queries on the effect of soy isoflavones on thyroid function and the underlying mechanism of action. Materials and Methods: We examined the effect of soy isoflavones on reverse tri-iodothyronine (or 3,3',5'-tri-iodothyronine; rT3) in two studies comprising 400 patients: 200 men (study 1; 3 months) and 200 post-menopausal women (study 2; 6 months) who were randomized to consume 15 g soy protein with 66 mg of isoflavones (SPI) daily, or 15 g soy protein alone without isoflavones (SP) daily. Results: SPI supplementation increased rT3 serum concentration in both men 0.41 (0.12) vs. 0.45 (0.14) nmol/L and women 0.33 (0.12) vs. 0.37 (0.09) nmol/L at 3 months compared to SP that was not seen at 6 months. Thyroid stimulating hormone (TSH) serum concentrations increased while free thyroxine (fT4) concentrations decreased with 3 months of SPI compared to SP supplementation for both men and women. rT3 correlated with TSH in both studies (p = 0.03) but not with either fT3 or fT4. fT3 levels did not differ between the SPI and SP preparations. Conclusion: Soy isoflavones transiently increased rT3 levels within 3 months though reverted to baseline at 6 months. The mechanism for this would be either rT3 degrading deiodinase 1 and/or deiodinase 2 activities are transiently inhibited at 3 months, or inhibition of deiodinase 3, which generates rT3 from T4 is induced at 6 months. These changes were mirrored in the TSH concentrations, suggesting that short-term high dose isoflavone transiently impairs thyroid function in the first 3 months and may impact on general health during this period. ISRCTN Registry: ISRCTN 90604927; ISRCTN34051237.
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Affiliation(s)
- Thozhukat Sathyapalan
- Academic Diabetes, Endocrinology and Metabolism, Hull York Medical School, University of Hull, Hull, United Kingdom
| | - Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Berlin Institute of Health, CVK, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Eddy Rijntjes
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Berlin Institute of Health, CVK, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Alan S. Rigby
- Academic Diabetes, Endocrinology and Metabolism, Hull York Medical School, University of Hull, Hull, United Kingdom
| | | | - Eric S. Kilpatrick
- Department of Clinical Chemistry, Sidra Medical and Research Center, Doha, Qatar
| | - Stephen L. Atkin
- Weill Cornell Medical College Qatar, Doha, Qatar
- *Correspondence: Stephen L. Atkin
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16
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Schweizer U, Towell H, Vit A, Rodriguez-Ruiz A, Steegborn C. Structural aspects of thyroid hormone binding to proteins and competitive interactions with natural and synthetic compounds. Mol Cell Endocrinol 2017; 458:57-67. [PMID: 28131741 DOI: 10.1016/j.mce.2017.01.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 01/11/2017] [Accepted: 01/17/2017] [Indexed: 12/25/2022]
Abstract
Thyroid hormones and their metabolites constitute a vast class of related iodothyronine compounds that contribute to the regulation of metabolic activity and cell differentiation. They are in turn transported, transformed and recognized as signaling molecules through binding to a variety of proteins from a wide range of evolutionary unrelated protein families, which renders these proteins and their iodothyronine binding sites an example for extensive convergent evolution. In this review, we will briefly summarize what is known about iodothyronine binding sites in proteins, the modes of protein/iodothyronine interaction, and the ligand conformations. We will then discuss physiological and synthetic compounds, including popular drugs and food components, that can interfere with iodothyronine binding and recognition by these proteins. The discussion also includes compounds persisting in the environment and acting as endocrine disrupting chemicals.
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Affiliation(s)
- Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.
| | - Holly Towell
- Lehrstuhl für Biochemie, Universität Bayreuth, Bayreuth, Germany
| | - Allegra Vit
- Lehrstuhl für Biochemie, Universität Bayreuth, Bayreuth, Germany
| | - Alfonso Rodriguez-Ruiz
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
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17
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Šošić-Jurjević B, Lütjohann D, Jarić I, Miler M, Vojnović Milutinović D, Filipović B, Ajdžanović V, Renko K, Wirth EK, Janković S, Kӧhrle J, Milošević V. Effects of age and soybean isoflavones on hepatic cholesterol metabolism and thyroid hormone availability in acyclic female rats. Exp Gerontol 2017; 92:74-81. [PMID: 28336316 DOI: 10.1016/j.exger.2017.03.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/13/2017] [Accepted: 03/13/2017] [Indexed: 11/23/2022]
Abstract
Soy-food and its isoflavones, genistein (G) and daidzein (D), were reported to exert mild cholesterol-lowering effect, but the underlying mechanism is still unclear. In this research, first we studied age-related alterations in hepatic cholesterol metabolism of acyclic middle-aged (MA) female rats. Then we tested if purified isoflavones may prevent or reverse these changes, and whether putative changes in hepatic thyroid hormone availability may be associated with this effect. Serum and hepatic total cholesterol (TChol), bile acid and cholesterol precursors, as well as serum TSH and T4 concentrations, hepatic deiodinase (Dio) 1 enzyme activity and MCT8 protein expression were determined by comparing data obtained for MA with young adult (YA) intact (IC) females. Effects of subcutaneously administered G or D (35mg/kg) to MA rats were evaluated versus vehicle-treated MA females. MA IC females were characterized by: higher (p<0.05) serum TChol, lower (p<0.05) hepatic TChol and its biosynthetic precursors, lower (p<0.05) hepatic 7α-hydroxycholesterol but elevated (p<0.05) 27- and 24-hydroxycholesterol in comparison to YA IC. Both isoflavone treatments decreased (p<0.05) hepatic 27-hydroxycholesterol, G being more effective than D, without affecting any other parameter of Chol metabolism. Only G elevated hepatic Dio1 activity (p<0.05). In conclusion, age-related hypercholesteremia was associated with lower hepatic Chol synthesis and shift from main neutral (lower 7α-hydroxycholesterol) to alternative acidic pathway (higher 27-hydroxycholesterol) of Chol degradation to bile acid. Both isoflavones lowered hepatic 27-hydroxycholesterol, which may be considered beneficial. Only G treatment increased hepatic Dio1 activity, thus indicating local increase in thyroid hormones, obviously insufficient to induce prominent cholesterol-lowering effect.
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Affiliation(s)
- Branka Šošić-Jurjević
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia.
| | - Dieter Lütjohann
- Institut für Klinische Chemie und Klinische Pharmakologie Universitätsklinikum Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany
| | - Ivana Jarić
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - Marko Miler
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - Danijela Vojnović Milutinović
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - Branko Filipović
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - Vladimir Ajdžanović
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - Kostja Renko
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Eva Katrin Wirth
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Snežana Janković
- Institute for Science Application in Agriculture, University of Belgrade, Despot Stefan Blvd. 68b, 11000 Belgrade, Serbia
| | - Josef Kӧhrle
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Verica Milošević
- Institute for Biological Research "Siniša Stanković", University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
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18
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Hoefig CS, Zucchi R, Köhrle J. Thyronamines and Derivatives: Physiological Relevance, Pharmacological Actions, and Future Research Directions. Thyroid 2016; 26:1656-1673. [PMID: 27650974 DOI: 10.1089/thy.2016.0178] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Thyronamines (3-T1AM, T0AM) are endogenous compounds probably derived from L-thyroxine or its intermediate metabolites. Combined activities of intestinal deiodinases and ornithine decarboxylase generate 3-T1AM in vitro. Alternatively, 3-T1AM might be formed by the thyroid gland and secreted into the blood. 3-T1AM and T0AM concentrations have been determined by liquid chromatography-tandem mass spectrometry analysis (LC-MS/MS) in tissues, serum, and cell lines. However, large variations of 3-T1AM concentrations in human serum were reported by LC-MS/MS compared with a monoclonal antibody-based immunoassay. These differences might be caused by strong binding of the highly hydrophobic 3-T1AM to apolipoprotein B100. Pharmacological administration of 3-T1AM results in dose-dependent reversible effects on body temperature, cardiac function, energy metabolism, and neurological functions. The physiological relevance of these actions is unclear, but may occur at tissue concentrations close to the estimated endogenous concentrations of 3-T1AM or its metabolites T0AM or thyroacetic acid (TA1). A number of putative receptors, binding sites, and cellular target molecules mediating actions of the multi-target ligand 3-T1AM have been proposed. Among those are members of the trace amine associated receptor family, the adrenergic receptor ADRα2a, and the thermosensitive transient receptor potential melastatin 8 channel. Preclinical studies employing various animal experimental models are in progress, and more stable receptor-selective agonistic and antagonistic analogues of 3-T1AM are now available for testing. The potent endogenous thyroid hormone-derived biogenic amine 3-T1AM exerts marked cryogenic, metabolic, cardiac and central actions and represents a valuable lead compound linking endocrine, metabolic, and neuroscience research to advance development of new drugs.
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Affiliation(s)
- Carolin Stephanie Hoefig
- 1 Institut für Experimentelle Endokrinologie Charité, Universitätsmedizin Berlin , Berlin, Germany
| | - Riccardo Zucchi
- 2 Laboratory of Biochemistry, Department of Pathology, University of Pisa , Pisa, Italy
| | - Josef Köhrle
- 1 Institut für Experimentelle Endokrinologie Charité, Universitätsmedizin Berlin , Berlin, Germany
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19
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Garg S, Lule VK, Malik RK, Tomar SK. Soy Bioactive Components in Functional Perspective: A Review. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2016. [DOI: 10.1080/10942912.2015.1136936] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Sheenam Garg
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India
| | - Vaibhao Kisanrao Lule
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India
| | - Ravinder Kumar Malik
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India
| | - Sudhir Kumar Tomar
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India
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20
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Soni M, White LR, Kridawati A, Bandelow S, Hogervorst E. Phytoestrogen consumption and risk for cognitive decline and dementia: With consideration of thyroid status and other possible mediators. J Steroid Biochem Mol Biol 2016; 160:67-77. [PMID: 26535810 DOI: 10.1016/j.jsbmb.2015.10.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 09/07/2015] [Accepted: 10/29/2015] [Indexed: 12/13/2022]
Abstract
It is predicted that around 20% of the worlds population will be age 60 or above by 2050. Prevalence of cognitive decline and dementia is high in older adults and modifiable dietary factors may be able to reduce risk for these conditions. Phytoestrogens are bioactive plant chemicals found in soy, which have a similarity in structure to natural estradiol (the most abundant circulating estrogen). This structural likeness enables phytoestrogens to interact with estrogen receptors in the brain, potentially affecting cognition. However, findings in this domain are largely inconsistent, with approximately 50% of studies showing positive effects of phytoestrogens on cognition and the other half resulting in null/negative findings. This paper provides an updated review of the relationship between consumption of phytoestrogens and risk for cognitive decline and/or dementia. In particular, possible mediators were identified to explain discrepant findings and for consideration in future research. A case can be made for a link between phytoestrogen consumption, thyroid status and cognition in older age, although current findings in this area are very limited. Evidence suggests that inter-individual variants that can affect phytoestrogen bioavailability (and thus cognitive outcome) include age and ability to breakdown ingested phytoestrogens into their bioactive metabolites. Factors of the study design that must be taken into account are type of soy product, dosage, frequency of dietary intake and type of cognitive test used. Guidelines regarding optimal phytoestrogen dosage and frequency of intake are yet to be determined.
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Affiliation(s)
- M Soni
- School of Sport Exercise and Health Sciences, National Centre for Sports and Exercise Medicine, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom
| | - L R White
- Pacific Health Research and Education Institute, Kuakini Physicians Tower, 405 N. Juakini St., Ste. 1111, Honolulu, HI 96817, USA.
| | - A Kridawati
- Department of Public Health, Respati University Yogyakarta, Indonesia.
| | - S Bandelow
- Department of Public Health, Respati University Yogyakarta, Indonesia.
| | - E Hogervorst
- School of Sport Exercise and Health Sciences, National Centre for Sports and Exercise Medicine, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom.
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21
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Polsinelli I, Nencetti S, Shepard W, Ciccone L, Orlandini E, Stura EA. A new crystal form of human transthyretin obtained with a curcumin derived ligand. J Struct Biol 2016; 194:8-17. [PMID: 26796656 DOI: 10.1016/j.jsb.2016.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 01/14/2016] [Accepted: 01/16/2016] [Indexed: 12/18/2022]
Abstract
Transthyretin (TTR), a 54kDa homotetrameric protein that transports thyroxine (T4), has been associated with clinical cases of TTR amyloidosis for its tendency to aggregate to form fibrils. Many ligands with a potential to inhibit fibril formation have been studied by X-ray crystallography in complex with TTR. Unfortunately, the ligand is often found in ambiguous electron density that is difficult to interpret. The ligand validation statistics suggest over-interpretation, even for the most active compounds like diflunisal. The primary technical reason is its position on a crystallographic 2-fold axis in the most common crystal form. Further investigations with the use of polyethylene glycol (PEG) to crystallize TTR complexes have resulted in a new trigonal polymorph with two tetramers in the asymmetric unit. The ligand used to obtain this new polymorph, 4-hydroxychalcone, is related to curcumin. Here we evaluate this crystal form to understand the contribution it may bring to the study of TTR ligands complexes, which are often asymmetric.
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Affiliation(s)
- Ivan Polsinelli
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin, BP 48, 91192 Gif-sur-Yvette, France; Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Susanna Nencetti
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - William Shepard
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Lidia Ciccone
- Dipartimento di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | | | - Enrico A Stura
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin, BP 48, 91192 Gif-sur-Yvette, France; CEA, iBiTec-S, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), Gif-sur-Yvette F-91191, France.
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22
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Braun D, Schweizer U. Efficient Activation of Pathogenic ΔPhe501 Mutation in Monocarboxylate Transporter 8 by Chemical and Pharmacological Chaperones. Endocrinology 2015; 156:4720-30. [PMID: 26368820 DOI: 10.1210/en.2015-1393] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Monocarboxylate transporter 8 (MCT8) is a thyroid hormone transmembrane transporter expressed in many cell types, including neurons. Mutations that inactivate transport activity of MCT8 cause severe X-linked psychomotor retardation in male patients, a syndrome originally described as the Allan-Herndon-Dudley syndrome. Treatment options currently explored the focus on finding thyroid hormone-like compounds that bypass MCT8 and enter cells through different transporters. Because MCT8 is a multipass transmembrane protein, some pathogenic mutations affect membrane trafficking while potentially retaining some transporter activity. We explore here the effects of chemical and pharmacological chaperones on the expression and transport activity of the MCT8 mutant ΔPhe501. Dimethylsulfoxide, 4-phenylbutyric acid as well as its sodium salt, and the isoflavone genistein increase T3 uptake into MDCK1 cells stably transfected with mutant MCT8-ΔPhe501. We show that ΔPhe501 represents a temperature-sensitive mutant protein that is stabilized by the proteasome inhibitor MG132. 4-Phenylbutyrate has been used to stabilize ΔPhe508 mutant cystic fibrosis transmembrane conductance regulator protein and is in clinical use in patients with urea cycle defects. Genistein is enriched in soy and available as a nutritional supplement. It is effective in stabilizing MCT8-ΔPhe501 at 100 nM concentration. Expression of the L471P mutant is increased in response to phenylbutyrate, but T3 uptake activity is not induced, supporting the notion that the chaperone specifically increases membrane expression. Our findings suggest that certain pathogenic MCT8 mutants may be responsive to (co-)treatment with readily available compounds, which increase endogenous protein function.
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Affiliation(s)
- Doreen Braun
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität, 53115 Bonn, Germany
| | - Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität, 53115 Bonn, Germany
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23
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Kurrat A, Blei T, Kluxen FM, Mueller DR, Piechotta M, Soukup ST, Kulling SE, Diel P. Lifelong exposure to dietary isoflavones reduces risk of obesity in ovariectomized Wistar rats. Mol Nutr Food Res 2015; 59:2407-18. [PMID: 26346629 DOI: 10.1002/mnfr.201500240] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 08/20/2015] [Accepted: 08/23/2015] [Indexed: 12/17/2022]
Abstract
SCOPE Traditional Asian diet rich in soy isoflavones (ISOs) is discussed to be linked to a lower obesity prevalence. In lifelong and short-term exposure scenarios we investigated effects of an ISO-rich diet on the body composition and development of obesity in female rats. METHODS AND RESULTS Female Wistar rats grew up on ISO-free or ISO-rich control diet (CON ISO: 467 mg/kg diet). Starting postnatal day 83, ovariectomized and intact animals received high calorie Western diet (WD) in the absence or presence of ISO (WD ISO: 431 mg/kg diet) for 12 weeks to induce obesity or maintained on respective control diet (CON). One group starting ISO exposure after ovariectomy mimics short-term ISO exposure in postmenopausal Western women. Lifelong but not short-term ISO exposure resulted in reduced body weight, visceral fat mass, serum leptin, and smaller adipocytes. ISO decreased hepatic SREBP-1c, ACC, FAS, and PPARγ mRNA expression in nonobese animals. Moreover, ovariectomy reduced skeletal muscle weight, which was antagonized by both short-term and lifelong ISO exposure. CONCLUSION Our results indicate that in female rats lifelong but not short-term ISO intake reduces the risk to develop obesity. Furthermore, lifelong and short-term ISO exposure may antagonize loss of skeletal muscle mass induced by ovariectomy.
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Affiliation(s)
- Anne Kurrat
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany
| | - Tina Blei
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany
| | - Felix M Kluxen
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany
| | - Dennis R Mueller
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany
| | - Marion Piechotta
- Clinic for Cattle, Endocrinology, University of Veterinary Medicine, Hannover, Germany
| | - Sebastian T Soukup
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Karlsruhe, Germany
| | - Sabine E Kulling
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut, Karlsruhe, Germany
| | - Patrick Diel
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sports University, Cologne, Germany
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24
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Florio P, Folli C, Cianci M, Del Rio D, Zanotti G, Berni R. Transthyretin Binding Heterogeneity and Anti-amyloidogenic Activity of Natural Polyphenols and Their Metabolites. J Biol Chem 2015; 290:29769-80. [PMID: 26468275 DOI: 10.1074/jbc.m115.690172] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Indexed: 12/11/2022] Open
Abstract
Transthyretin (TTR) is an amyloidogenic protein, the amyloidogenic potential of which is enhanced by a number of specific point mutations. The ability to inhibit TTR fibrillogenesis is known for several classes of compounds, including natural polyphenols, which protect the native state of TTR by specifically interacting with its thyroxine binding sites. Comparative analyses of the interaction and of the ability to protect the TTR native state for polyphenols, both stilbenoids and flavonoids, and some of their main metabolites have been carried out. A main finding of this investigation was the highly preferential binding of resveratrol and thyroxine, both characterized by negative binding cooperativity, to distinct sites in TTR, consistent with the data of x-ray analysis of TTR in complex with both ligands. Although revealing the ability of the two thyroxine binding sites of TTR to discriminate between different ligands, this feature has allowed us to evaluate the interactions of polyphenols with both resveratrol and thyroxine preferential binding sites, by using resveratrol and radiolabeled T4 as probes. Among flavonoids, genistein and apigenin were able to effectively displace resveratrol from its preferential binding site, whereas genistein also showed the ability to interact, albeit weakly, with the preferential thyroxine binding site. Several glucuronidated polyphenol metabolites did not exhibit significant competition for resveratrol and thyroxine preferential binding sites and lacked the ability to stabilize TTR. However, resveratrol-3-O-sulfate was able to significantly protect the protein native state. A rationale for the in vitro properties found for polyphenol metabolites was provided by x-ray analysis of their complexes with TTR.
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Affiliation(s)
- Paola Florio
- From the Department of Life Sciences, University of Parma, 43124 Parma, Italy
| | - Claudia Folli
- the Department of Food Science, University of Parma, 43124 Parma, Italy
| | - Michele Cianci
- the European Molecular Biology Laboratory, 22607 Hamburg, Germany, and
| | - Daniele Del Rio
- the Department of Food Science, University of Parma, 43124 Parma, Italy
| | - Giuseppe Zanotti
- the Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Rodolfo Berni
- From the Department of Life Sciences, University of Parma, 43124 Parma, Italy,
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Renko K, Schäche S, Hoefig CS, Welsink T, Schwiebert C, Braun D, Becker NP, Köhrle J, Schomburg L. An Improved Nonradioactive Screening Method Identifies Genistein and Xanthohumol as Potent Inhibitors of Iodothyronine Deiodinases. Thyroid 2015; 25:962-8. [PMID: 25962824 DOI: 10.1089/thy.2015.0058] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Deiodinases (DIO1, 2, and 3) are key enzymes in thyroid hormone (TH) activation and inactivation with impact on energy metabolism, development, cell differentiation, and a number of other physiological processes. The three DIO isoenzymes thus constitute sensitive rate-limiting components within the TH axis, prone to dysregulation by endocrine disruptive compounds or disease state. In animal models and cell culture experiments, they serve as readout for local TH status and disarrangement of the hormonal axis. Furthermore, some human diseases are characterized by apparent deiodinase dysregulation (e.g., the low triiodothyronine syndrome in critical illness). Consequently, these enzymes are targets of interest for the development of pharmacological compounds with modulatory activities. Until now, the portfolio of inhibitors for these enzymes is limited. In the clinics, the DIO1-specific inhibitor propylthiouracil is in use for treatment of severe hyperthyroidism. Other well-known inhibitors (e.g., iopanoic acid or aurothioglucose) are nonselective and block all three isoenzymes. Furthermore, DIO3 was shown to be a potential oncogenic gene, which is strongly expressed in some tumors and might, in consequence, protect tumor tissue form differentiation by TH. With respect to its role in tumorigenesis, specific inhibitors of DIO3 as a potential target for anticancer drugs would be highly desirable. To this end, a flexible and convenient assay for high-throughput screening is needed. We recently described a nonradioactive screening assay, utilizing the classic Sandell-Kolthoff reaction as readout for iodide release from the substrate molecules. While we used murine liver as enzyme source, the assay was limited to murine DIO1 activity testing. Here, we describe the use of recombinant proteins as enzyme sources within the assay, expanding its suitability from murine Dio1 to human DIO1, DIO2, and DIO3. METHODS As proof-of-concept, deiodination reactions catalyzed by these recombinant enzymes were monitored with various nonradioactive substrates and confirmed by liquid chromatography-tandem mass spectrometry. RESULTS The contrast agent and known DIO inhibitor iopanoic acid was characterized as readily accepted substrate by DIO2 and Dio3. In a screening approach using established endocrine disrupting compounds, the natural food ingredient genistein was identified as a further DIO1-specific inhibitor, while xanthohumol turned out to potently block the activity of all three isoenzymes. CONCLUSIONS A rapid nonradioactive screening method based on the Sandell-Kolthoff reaction is suitable for identification of environmental, nutritive and pharmacological compounds modulating activities of human deiodinase enzymes.
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Affiliation(s)
- Kostja Renko
- 1 Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin , Berlin, Germany
| | - Sonja Schäche
- 1 Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin , Berlin, Germany
| | - Carolin S Hoefig
- 2 Karolinska Institutet , Department of Cellular and Molecular Biology, Stockholm, Sweden
| | - Tim Welsink
- 1 Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin , Berlin, Germany
| | - Christian Schwiebert
- 1 Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin , Berlin, Germany
| | - Doreen Braun
- 3 Institut für Biochemie und Molekularbiologie, Rheinische Friedrich Wilhelms-Universität Bonn, Bonn , Germany
| | - Niels-Peter Becker
- 1 Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin , Berlin, Germany
| | - Josef Köhrle
- 1 Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin , Berlin, Germany
| | - Lutz Schomburg
- 1 Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin , Berlin, Germany
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Šošić-Jurjević B, Filipović B, Wirth EK, Živanović J, Radulović N, Janković S, Milošević V, Köhrle J. Soy isoflavones interfere with thyroid hormone homeostasis in orchidectomized middle-aged rats. Toxicol Appl Pharmacol 2014; 278:124-34. [PMID: 24793811 DOI: 10.1016/j.taap.2014.04.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/17/2014] [Accepted: 04/18/2014] [Indexed: 01/10/2023]
Abstract
We previously reported that genistein (G) and daidzein (D) administered subcutaneously (10mg/kg) induce changes in the angio-follicular units of the thyroid gland, reduce concentration of total thyroid hormones (TH) and increase thyrotropin (TSH) in serum of orchidectomized middle-aged (16-month-old) rats. To further investigate these effects, we now examined expression levels of the thyroglobulin (Tg), thyroperoxidase (Tpo), vascular endothelial growth factor A (Vegfa) and deiodinase type 1 (Dio 1) genes in the thyroid; in the pituitary, genes involved in TH feedback control (Tsh β, Dio 1, Dio 2, Trh receptor); and in the liver and kidney, expression of T3-activated genes Dio 1 and Spot 14, as well as transthyretin (Ttr), by quantitative real-time PCR. We also analyzed TPO-immunopositivity and immunofluorescence of T4 bound to Tg, determined thyroid T4 levels and measured deiodinase enzyme activities in examined organs. Decreased expression of Tg and Tpo genes (p<0.05) correlated with immunohistochemical staining results, and together with decreased serum total T4 levels, indicates decreased Tg and TH synthesis following treatments with both isoflavones. However, expression of Spot 14 (p<0.05) gene in liver and kidney was up-regulated, and liver Dio 1 expression and activity (p<0.05) increased. At the level of pituitary, no significant change in gene expression levels, or Dio 1 and 2 enzyme activities was observed. In conclusion, both G and D impaired Tg and TH synthesis, but at the same time increased tissue availability of TH in peripheral tissues of Orx middle-aged rats.
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Affiliation(s)
- Branka Šošić-Jurjević
- Institute for Biological Research, Siniša Stanković, University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia.
| | - Branko Filipović
- Institute for Biological Research, Siniša Stanković, University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - Eva Katrin Wirth
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
| | - Jasmina Živanović
- Institute for Biological Research, Siniša Stanković, University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - Niko Radulović
- Department of Chemistry, Faculty of Science and Mathematics, University of Niš, Višegradska 33, 18000 Niš, Serbia
| | - Snežana Janković
- Institute for Science Application in Agriculture, University of Belgrade, Despot Stefan Blvd. 68b, 11000 Belgrade, Serbia
| | - Verica Milošević
- Institute for Biological Research, Siniša Stanković, University of Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade, Serbia
| | - Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany
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Murk AJ, Rijntjes E, Blaauboer BJ, Clewell R, Crofton KM, Dingemans MML, Furlow JD, Kavlock R, Köhrle J, Opitz R, Traas T, Visser TJ, Xia M, Gutleb AC. Mechanism-based testing strategy using in vitro approaches for identification of thyroid hormone disrupting chemicals. Toxicol In Vitro 2013; 27:1320-46. [PMID: 23453986 DOI: 10.1016/j.tiv.2013.02.012] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 02/07/2013] [Accepted: 02/18/2013] [Indexed: 11/16/2022]
Abstract
The thyroid hormone (TH) system is involved in several important physiological processes, including regulation of energy metabolism, growth and differentiation, development and maintenance of brain function, thermo-regulation, osmo-regulation, and axis of regulation of other endocrine systems, sexual behaviour and fertility and cardiovascular function. Therefore, concern about TH disruption (THD) has resulted in strategies being developed to identify THD chemicals (THDCs). Information on potential of chemicals causing THD is typically derived from animal studies. For the majority of chemicals, however, this information is either limited or unavailable. It is also unlikely that animal experiments will be performed for all THD relevant chemicals in the near future for ethical, financial and practical reasons. In addition, typical animal experiments often do not provide information on the mechanism of action of THDC, making it harder to extrapolate results across species. Relevant effects may not be identified in animal studies when the effects are delayed, life stage specific, not assessed by the experimental paradigm (e.g., behaviour) or only occur when an organism has to adapt to environmental factors by modulating TH levels. Therefore, in vitro and in silico alternatives to identify THDC and quantify their potency are needed. THDC have many potential mechanisms of action, including altered hormone production, transport, metabolism, receptor activation and disruption of several feed-back mechanisms. In vitro assays are available for many of these endpoints, and the application of modern '-omics' technologies, applicable for in vivo studies can help to reveal relevant and possibly new endpoints for inclusion in a targeted THDC in vitro test battery. Within the framework of the ASAT initiative (Assuring Safety without Animal Testing), an international group consisting of experts in the areas of thyroid endocrinology, toxicology of endocrine disruption, neurotoxicology, high-throughput screening, computational biology, and regulatory affairs has reviewed the state of science for (1) known mechanisms for THD plus examples of THDC; (2) in vitro THD tests currently available or under development related to these mechanisms; and (3) in silico methods for estimating the blood levels of THDC. Based on this scientific review, the panel has recommended a battery of test methods to be able to classify chemicals as of less or high concern for further hazard and risk assessment for THD. In addition, research gaps and needs are identified to be able to optimize and validate the targeted THD in vitro test battery for a mechanism-based strategy for a decision to opt out or to proceed with further testing for THD.
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Affiliation(s)
- AlberTinka J Murk
- Wageningen University, Sub-department of Toxicology, Tuinlaan 5, 6703 HE Wageningen, The Netherlands.
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28
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Ribeiro CA, Saraiva MJ, Cardoso I. Stability of the transthyretin molecule as a key factor in the interaction with a-beta peptide--relevance in Alzheimer's disease. PLoS One 2012; 7:e45368. [PMID: 23028965 PMCID: PMC3444465 DOI: 10.1371/journal.pone.0045368] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 08/21/2012] [Indexed: 11/19/2022] Open
Abstract
Transthyretin (TTR) protects against A-Beta toxicity by binding the peptide thus inhibiting its aggregation. Previous work showed different TTR mutations interact differently with A-Beta, with increasing affinities correlating with decreasing amyloidogenecity of the TTR mutant; this did not impact on the levels of inhibition of A-Beta aggregation, as assessed by transmission electron microscopy. Our work aimed at probing differences in binding to A-Beta by WT, T119M and L55P TTR using quantitative assays, and at identifying factors affecting this interaction. We addressed the impact of such factors in TTR ability to degrade A-Beta. Using a dot blot approach with the anti-oligomeric antibody A11, we showed that A-Beta formed oligomers transiently, indicating aggregation and fibril formation, whereas in the presence of WT and T119M TTR the oligomers persisted longer, indicative that these variants avoided further aggregation into fibrils. In contrast, L55PTTR was not able to inhibit oligomerization or to prevent evolution to aggregates and fibrils. Furthermore, apoptosis assessment showed WT and T119M TTR were able to protect against A-Beta toxicity. Because the amyloidogenic potential of TTR is inversely correlated with its stability, the use of drugs able to stabilize TTR tetrameric fold could result in increased TTR/A-Beta binding. Here we showed that iododiflunisal, 3-dinitrophenol, resveratrol, [2-(3,5-dichlorophenyl)amino] (DCPA) and [4-(3,5-difluorophenyl)] (DFPB) were able to increase TTR binding to A-Beta; however only DCPA and DFPB improved TTR proteolytic activity. Thyroxine, a TTR ligand, did not influence TTR/A-Beta interaction and A-Beta degradation by TTR, whereas RBP, another TTR ligand, not only obstructed the interaction but also inhibited TTR proteolytic activity. Our results showed differences between WT and T119M TTR, and L55PTTR mutant regarding their interaction with A-Beta and prompt the stability of TTR as a key factor in this interaction, which may be relevant in AD pathogenesis and for the design of therapeutic TTR-based therapies.
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Affiliation(s)
- Carlos A. Ribeiro
- Molecular Neurobiology Unit, IBMC- Instituto de Biologia Molecular e Celular, Porto, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, Porto Portugal
| | - Maria João Saraiva
- Molecular Neurobiology Unit, IBMC- Instituto de Biologia Molecular e Celular, Porto, Portugal
- ICBAS- Instituto de Ciências Biomédicas Abel Salazar, Porto Portugal
| | - Isabel Cardoso
- Molecular Neurobiology Unit, IBMC- Instituto de Biologia Molecular e Celular, Porto, Portugal
- Escola Superior de Tecnologia da Saúde do Porto, Instituto Politécnico do Porto, Vila Nova de Gaia, Portugal
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29
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Hirohata M, Ono K, Takasaki JI, Takahashi R, Ikeda T, Morinaga A, Yamada M. Anti-amyloidogenic effects of soybean isoflavones in vitro: Fluorescence spectroscopy demonstrating direct binding to Aβ monomers, oligomers and fibrils. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1822:1316-24. [PMID: 22587837 DOI: 10.1016/j.bbadis.2012.05.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 04/21/2012] [Accepted: 05/08/2012] [Indexed: 01/28/2023]
Abstract
Alzheimer's disease is characterized by the presence of extracellular deposits of amyloid, primarily composed of the amyloid β-protein (Aβ). A growing body of evidence indicates that oligomeric forms of Aβ play a critical role in disease causation. Soybean isoflavones are flavonoids with an isoflavone backbone. Isoflavones have been reported to protect against Aβ-induced neurotoxicity in cultured cell systems, the molecular mechanisms remain unclear. Our previous studies demonstrated that red wine-related flavonoids with a flavone backbone are able to inhibit Aβ assembly and destabilize preformed Aβ aggregates. Here, we show that isoflavones, especially glycitein and genistein, have anti-fibrillization, anti-oligomerization and fibril-destabilizing effects on Aβ(1-40) and Aβ(1-42)in vitro at physiological pH and temperature, by using nucleation-dependent polymerization monitored by thioflavin T fluorescence, atomic force microscopy, electron microscopy, and photo-induced cross-linking of unmodified proteins followed by SDS-PAGE. Our three-dimensional fluorescence spectroscopic analyses demonstrated that glycitein interacted with Aβ monomers, oligomers and fibrils, indicating specific binding of glycitein to these Aβ species. Glycitein also interacted with different Aβ fragments (Aβ(1-42), Aβ(1-40), Aβ(1-16) and Aβ(25-35)), exhibiting the highest fluorescence enhancement with Aβ(25-35). We speculated that glycitein's anti-amyloidogenic properties are specifically mediated by its binding to Aβ monomers, oligomers and fibrils. Isoflavones may hold promise as a treatment option for preventative strategies targeting amyloid formation in Alzheimer's disease.
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Affiliation(s)
- Mie Hirohata
- Department of Neurology and Neurobiology of Aging, Kanazawa University Graduate School of Medical Science, Kanazawa 920-8640, Japan
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30
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Thyroid and food: a Mediterranean perspective. MEDITERRANEAN JOURNAL OF NUTRITION AND METABOLISM 2012. [DOI: 10.1007/s12349-012-0095-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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31
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Skipor J, Misztal T, Piskuła M, Wiczkowski W, Thiéry JC. Phytoestrogens and thyroid hormone levels in the cerebrospinal fluid of ewes fed red clover silage. Small Rumin Res 2012. [DOI: 10.1016/j.smallrumres.2011.07.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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32
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Kumar S, Okello EJ, Harris JR. Experimental inhibition of fibrillogenesis and neurotoxicity by amyloid-beta (Aβ) and other disease-related peptides/proteins by plant extracts and herbal compounds. Subcell Biochem 2012; 65:295-326. [PMID: 23225009 DOI: 10.1007/978-94-007-5416-4_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Amyloid-β (Aβ) fibrillogenesis and associated cyto/neurotoxicity are major pathological events and hallmarks in diseases such as Alzheimer's disease (AD). The understanding of Aβ molecular pathogenesis is currently a pharmacological target for rational drug design and discovery based on reduction of Aβ generation, inhibition of Aβ fibrillogenesis and aggregation, enhancement of Aβ clearance and amelioration of associated cytotoxicity. Molecular mechanisms for other amyloidoses, such as transthyretin amyloidosis, AL-amyloidosis, as well as α-synuclein and prion protein are also pharmacological targets for current drug therapy, design and discovery. We report on natural herbal compounds and extracts that are capable binding to and inhibiting different targets associated with AD and other amyloid-associated diseases, providing a basis for future therapeutic strategies. Many herbal compounds, including curcumin, galantamine, quercetin and other polyphenols, are under active investigation and hold considerable potential for future prophylactic and therapeutic treatment against AD and other neurodegenerative diseases, as well as systemic amyloid diseases. A common emerging theme throughout many studies is the anti-oxidant and anti-inflammatory properties of the compounds or herbal extracts under investigation, within the context of the inhibition of cyto/neurotoxicity and anti-amyloid activity.
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Affiliation(s)
- Suresh Kumar
- University School of Biotechnology, GGS Indraprastha University, Sector 16C, 10075, Dwarka, Delhi, India,
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34
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Marini H, Polito F, Adamo EB, Bitto A, Squadrito F, Benvenga S. Update on genistein and thyroid: an overall message of safety. Front Endocrinol (Lausanne) 2012; 3:94. [PMID: 23060856 PMCID: PMC3459182 DOI: 10.3389/fendo.2012.00094] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 07/16/2012] [Indexed: 12/15/2022] Open
Abstract
Genistein aglycone, one of the soy isoflavones, has been reported to be beneficial in the treatment of menopausal vasomotor symptoms, osteoporosis, and cardiovascular diseases, as well as in a variety of cancers. However, issues of potential harm on thyroid function resulting from soy isoflavones consumption have been raised. Much of the evidence for the goitrogenic effects of isoflavones is derived from experimental in vitro and in vivo studies. Goitrogenic effects were also noted in infants fed non-iodine-fortified, soy-based formula, a problem that was easily solved with iodine fortification. Recent studies suggest that genistein shows a good profile of safety on the thyroid although definitive conclusions have not reached. The aim of this brief review is to summarize and better clarify the effects of genistein on human thyroid health.
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Affiliation(s)
- Herbert Marini
- Section of Physiology and Human Nutrition, Department of Biochemical, Physiological and Nutritional Sciences, University of Messina,Messina, Italy
- Herbert Marini, Francesca Polito, and Elena B. Adamo have contributed equally to this work
| | - Francesca Polito
- Section of Physiology and Human Nutrition, Department of Biochemical, Physiological and Nutritional Sciences, University of Messina,Messina, Italy
- Herbert Marini, Francesca Polito, and Elena B. Adamo have contributed equally to this work
| | - Elena B. Adamo
- Section of Physiology and Human Nutrition, Department of Biochemical, Physiological and Nutritional Sciences, University of Messina,Messina, Italy
- Herbert Marini, Francesca Polito, and Elena B. Adamo have contributed equally to this work
| | - Alessandra Bitto
- Section of Pharmacology, Department of Clinical and Experimental Medicine and Pharmacology, University of Messina,Messina, Italy
| | - Francesco Squadrito
- Section of Pharmacology, Department of Clinical and Experimental Medicine and Pharmacology, University of Messina,Messina, Italy
| | - Salvatore Benvenga
- Section of Endocrinology, Department of Clinical and Experimental Medicine and Pharmacology, University of Messina,Messina, Italy
- Master on Childhood, Adolescent and Women’s Endocrine Health, University of Messina,Messina, Italy
- Interdepartmental Program of Molecular and Clinical Endocrinology, and Women’s Endocrine Health, University Hospital of Messina,Messina, Italy
- *Correspondence: Salvatore Benvenga, Department of Clinical and Experimental Medicine and Pharmacology, Section of Endocrinology, Azienda Ospedaliera Universitaria Policlinico “G. Martino”, Pad. H 4th Floor, Via C. Valeria, Gazzi, 98125 Messina, Italy. e-mail:
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Abstract
A high intake of fruits and vegetables is associated with a lower risk of cancer. In this context, considerable attention is paid to Asian populations who consume high amounts of soy and soy-derived isoflavones, and have a lower risk for several cancer types such as breast and prostate cancers than populations in Western countries. Hence, interest focuses on soyfoods, soy products, and soy ingredients such as isoflavones with regard to their possible beneficial effects that were observed in numerous experiments and studies. The outcomes of the studies are not always conclusive, are often contradictory depending on the experimental conditions, and are, therefore, difficult to interpret. Isoflavone research revealed not only beneficial but also adverse effects, for instance, on the reproductive system. This is also the case with tumor-promoting effects on, for example, breast tissue. Isoflavone extracts and supplements are often used for the treatment of menopausal symptoms and for the prevention of age-associated conditions such as cardiovascular diseases and osteoporosis in postmenopausal women. In relation to this, questions about the effectiveness and safety of isoflavones have to be clarified. Moreover, there are concerns about the maternal consumption of isoflavones due to the development of leukemia in infants. In contrast, men may benefit from the intake of isoflavones with regard to reducing the risk of prostate cancer. Therefore, this review examines the risks but also the benefits of isoflavones with regard to various kinds of cancer, which can be derived from animal and human studies as well as from in vitro experiments.
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Affiliation(s)
- Susanne Andres
- Department of Food Safety, Federal Institute for Risk Assessment, Berlin, Germany
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36
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Radović B, Hussong R, Gerhäuser C, Meinl W, Frank N, Becker H, Köhrle J. Xanthohumol, a prenylated chalcone from hops, modulates hepatic expression of genes involved in thyroid hormone distribution and metabolism. Mol Nutr Food Res 2010; 54 Suppl 2:S225-35. [PMID: 20461738 DOI: 10.1002/mnfr.200900489] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the present study, we analyzed the influence of xanthohumol (XN) on thyroid hormone (TH) distribution and metabolism in rats. A potent and selective competition of XN for thyroxine (T4) binding to transthyretin (IC(50)=1 microM at 1.7 nM [(125)I]T4) was found in human and rat sera in vitro. Female rats treated orally with XN showed increased hepatic expression of T4-binding globulin and decreased transthyretin and albumin. Thyrotropin levels and hepatic type 1 deiodinase activity were moderately increased. Northern blot analysis revealed diminished expression of liver sulfotransferase (Sult1a1) and uridine-diphosphate glucuronosyltransferase (Ugt1a1) after XN treatment. The transcript levels of constitutive androstane receptor (CAR), known to be involved in regulation of enzymes metabolizing hormones, drugs and xenobiotics, was lower in rats treated with >10 mg XN/kg body weight per day. Immunoblot analysis indicates reduced amounts of CAR protein. The phenobarbital-inducible cytochrome P450 mRNA level was decreased in rats treated with >10 mg XN/kg/day, in agreement with reduced CAR protein. Although only moderate changes in TH serum levels were observed, the XN-dependent altered expression of components involved in TH homeostasis might be important not only for hormone metabolism, but also for hepatic phase I and II elimination of drug metabolites and xenobiotics.
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Affiliation(s)
- Branislav Radović
- Institut für Experimentelle Endokrinologie & Endokrinologisches Forschungs-Centrum EnForCé, Charité Universitätsmedizin, Berlin, Germany.
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37
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Šošić-Jurjević B, Filipović B, Ajdžanović V, Savin S, Nestorović N, Milošević V, Sekulić M. Suppressive effects of genistein and daidzein on pituitary–thyroid axis in orchidectomized middle-aged rats. Exp Biol Med (Maywood) 2010; 235:590-8. [DOI: 10.1258/ebm.2009.009279] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
High intake of soybean phytoestrogens, isoflavones genistein (G) and daidzein (D), has been associated with health benefits. However, isoflavones were reported to affect adversely thyroid function in the presence of other goitrogenic factors. As the thyroid gland becomes functionally impaired with age, we examined whether supplementary doses of G or D would affect morphology and function of pituitary–thyroid axis in middle-aged male rats. Sixteen-month-old orchidectomized Wistar rats were treated with 10 mg/kg of either G or D, while the control sham-operated and orchidectomized group received just the vehicle for three weeks. The animals were fed soy-free diet with increased iodine content, and killed 24 h after the last treatment. Their pituitaries and thyroids were excised and prepared for further immunohistochemical and morphometric investigation. The concentrations of thyroid-stimulating hormone (TSH), total T4 and T3, in the serum were determined. In both isoflavone-treated groups, pituitary TSH-immunopositive cells had increased cellular volume and relative volume density ( P < 0.05), as well as increased serum TSH levels ( P < 0.05) in comparison to the controls; their thyroid tissue was characterized by increased volume of thyroglobulin-immunopositive epithelium ( P < 0.05), epithelial height and index of activation rate ( P < 0.05), while the volume of luminal colloid, and total serum T4 and T3 levels decreased ( P < 0.05) in comparison to the controls. In conclusion, this study provides the first direct evidence that both G and D can induce microfollicular changes in the thyroid tissue and reduce the level of thyroid hormones in Orx middle-aged male rats, a model of andropause. This reduction consequently led to a feedback stimulation of pituitary TSH cells. The detected stimulatory effect was higher in the daidzein-treated rats.
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Affiliation(s)
- Branka Šošić-Jurjević
- Institute for Biological Research ‘Siniša Stanković’, University of Belgrade, Despot Stefan Blvd 142, 11060 Belgrade
| | - Branko Filipović
- Institute for Biological Research ‘Siniša Stanković’, University of Belgrade, Despot Stefan Blvd 142, 11060 Belgrade
| | - Vladimir Ajdžanović
- Institute for Biological Research ‘Siniša Stanković’, University of Belgrade, Despot Stefan Blvd 142, 11060 Belgrade
| | - Svetlana Savin
- Institute for the Application of Nuclear Energy, 31b Banatska, 11080 Zemun, Serbia
| | - Nataša Nestorović
- Institute for Biological Research ‘Siniša Stanković’, University of Belgrade, Despot Stefan Blvd 142, 11060 Belgrade
| | - Verica Milošević
- Institute for Biological Research ‘Siniša Stanković’, University of Belgrade, Despot Stefan Blvd 142, 11060 Belgrade
| | - Milka Sekulić
- Institute for Biological Research ‘Siniša Stanković’, University of Belgrade, Despot Stefan Blvd 142, 11060 Belgrade
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Trivella DBB, Bleicher L, Palmieri LDC, Wiggers HJ, Montanari CA, Kelly JW, Lima LMTR, Foguel D, Polikarpov I. Conformational differences between the wild type and V30M mutant transthyretin modulate its binding to genistein: implications to tetramer stability and ligand-binding. J Struct Biol 2010; 170:522-31. [PMID: 20211733 DOI: 10.1016/j.jsb.2010.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 02/27/2010] [Accepted: 03/02/2010] [Indexed: 11/26/2022]
Abstract
Transthyretin (TTR) is a tetrameric beta-sheet-rich transporter protein directly involved in human amyloid diseases. It was recently found that the isoflavone genistein (GEN) potently inhibits TTR amyloid fibril formation (Green et al., 2005) and is therefore a promising candidate for TTR amyloidosis treatment. Here we used structural and biophysical approaches to characterize genistein binding to the wild type (TTRwt) and to its most frequent amyloidogenic variant, the V30M mutant. In a dose-dependent manner, genistein elicited considerable increases in both mutant and TTRwt stability as demonstrated by high hydrostatic pressure (HHP) and acid-mediated dissociation/denaturation assays. TTR:GEN crystal complexes and isothermal titration calorimetry (ITC) experiments showed that the binding mechanisms of genistein to the TTRwt and to V30M are different and are dependent on apoTTR structure conformations. Furthermore, we could also identify potential allosteric movements caused by genistein binding to the wild type TTR that explains, at least in part, the frequently observed negatively cooperative process between the two sites of TTRwt when binding ligands. These findings show that TTR mutants may present different ligand recognition and therefore are of value in ligand design for inhibiting TTR amyloidosis.
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Affiliation(s)
- Daniela B B Trivella
- Instituto de Física de São Carlos, Universidade de São Paulo, P.O. Box 369, 13560-970 São Carlos, SP, Brazil
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Wuttke W, Jarry H, Seidlova-Wuttke D. Definition, classification and mechanism of action of endocrine disrupting chemicals. Hormones (Athens) 2010; 9:9-15. [PMID: 20363717 DOI: 10.1007/bf03401276] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Wolfgang Wuttke
- Department of Endocrinology, University Medical Center Goettingen, Georg-August-University, Germany.
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Hofmann PJ, Schomburg L, Köhrle J. Interference of Endocrine Disrupters with Thyroid Hormone Receptor–Dependent Transactivation. Toxicol Sci 2009; 110:125-37. [DOI: 10.1093/toxsci/kfp086] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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41
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Köhrle J. Environment and endocrinology: The case of thyroidology. ANNALES D'ENDOCRINOLOGIE 2008; 69:116-22. [DOI: 10.1016/j.ando.2008.02.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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42
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Schmutzler C, Gotthardt I, Hofmann PJ, Radovic B, Kovacs G, Stemmler L, Nobis I, Bacinski A, Mentrup B, Ambrugger P, Grüters A, Malendowicz LK, Christoffel J, Jarry H, Seidlovà-Wuttke D, Wuttke W, Köhrle J. Endocrine disruptors and the thyroid gland--a combined in vitro and in vivo analysis of potential new biomarkers. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115 Suppl 1:77-83. [PMID: 18174954 PMCID: PMC2174406 DOI: 10.1289/ehp.9369] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Accepted: 10/23/2006] [Indexed: 05/17/2023]
Abstract
BACKGROUND There is growing evidence that, in addition to the reproductive system, the hypothalamic-pituitary-thyroid axis is a target of endocrine-disrupting compounds (EDCs). However, this is not reflected adequately in current screening and assessment procedures for endocrine activity that to date determine only general parameters of thyroid function. OBJECTIVE AND METHODS We used several in vitro and ex vivo assays in an attempt to identify suitable biomarkers for antithyroid action testing a selected panel of putative EDCs. RESULTS In vitro we detected stimulation or inhibition of iodide uptake into FRTL-5 rat thyroid cells, inhibition of thyroid hormone binding to transthyretin, agonistic or antagonistic effects in a thyroid hormone receptor-dependent reporter assay, and inhibition of thyroid peroxidase using a novel assay system based on human recombinant thyroperoxidase that might be suitable for routine screening for potential EDCs. In rats, chronic application of several EDCs led to changes in thyroid morphology, alterations of thyrotropin and thyroid hormone serum levels as well as alterations in peripheral thyroid hormone-regulated end points such as malic enzyme and type I 5'-deiodinase activity. CONCLUSIONS As the effects of EDCs do not reflect classic mechanisms of hormone-dependent regulation and feedback, we believe multitarget and multimodal actions of EDCs affect the hypothalamic-pituitary-thyroid axis. These complex effects require a diverse approach for screening, evaluation, and risk assessment of potential antithyroid compounds. This approach involves novel in vitro or cell-based screening assays in order to assess thyroid hormone synthesis, transport, metabolism, and action as well as in vivo assays to measure thyroid hormone-regulated tissue-specific and developmental end points in animals.
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Affiliation(s)
- Cornelia Schmutzler
- Institut für Experimentelle Endokrinologie, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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Mastorakos G, Karoutsou EI, Mizamtsidi M, Creatsas G. The menace of endocrine disruptors on thyroid hormone physiology and their impact on intrauterine development. Endocrine 2007; 31:219-37. [PMID: 17906368 DOI: 10.1007/s12020-007-0030-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 04/19/2007] [Accepted: 05/01/2007] [Indexed: 10/22/2022]
Abstract
The delivery of the appropriate thyroid hormones quantity to target tissues in euthyroidism is the result of unopposed synthesis, transport, metabolism, and excretion of these hormones. Thyroid hormones homeostasis depends on the maintenance of the circulating 'free' thyroid hormone reserves and on the development of a dynamic balance between the 'free' hormones reserves and those of the 'bound' hormones with the transport proteins. Disturbance of this hormone system, which is in constant interaction with other hormone systems, leads to an adaptational counter-response targeting to re-establish a new homeostatic equilibrium. An excessive disturbance is likely to result, however, in hypo- or hyper- thyroid clinical states. Endocrine disruptors are chemical substances forming part of 'natural' contaminating agents found in most ecosystems. There is abundant evidence that several key components of the thyroid hormones homeostasis are susceptible to the action of endocrine disruptors. These chemicals include some chlorinated organic compounds, polycyclic aromatic hydrocarbons, herbicides, and pharmaceutical agents. Intrauterine exposure to endocrine disruptors that either mimic or antagonize thyroid hormones can produce permanent developmental disorders in the structure and functioning of the brain, leading to behavioral changes. Steroid receptors are important determinants of the consequences of endocrine disruptors. Their interaction with thyroid hormones complicates the effect of endocrine disruptors. The aim of this review is to present the effect of endocrine disruptors on thyroid hormones physiology and their potential impact on intrauterine development.
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Affiliation(s)
- George Mastorakos
- Endocrine Unit, Second Department of Obstretics and Gynecology, Aretaieion Hospital, Athens University Medical School, Athens 10674, Greece.
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