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Estrogenic flavonoids and their molecular mechanisms of action. J Nutr Biochem 2023; 114:109250. [PMID: 36509337 DOI: 10.1016/j.jnutbio.2022.109250] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/02/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
Flavonoids are a major group of phytoestrogens associated with physiological effects, and ecological and social impacts. Although the estrogenic activity of flavonoids was reported by researchers in the fields of medical, environmental and food studies, their molecular mechanisms of action have not been comprehensively reviewed. The estrogenic activity of the respective classes of flavonoids, anthocyanidins/anthocyanins, 2-arylbenzofurans/3-arylcoumarins/α-methyldeoxybenzoins, aurones/chalcones/dihydrochalcones, coumaronochromones, coumestans, flavans/flavan-3-ols/flavan-4-ols, flavanones/dihydroflavonols, flavones/flavonols, homoisoflavonoids, isoflavans, isoflavanones, isoflavenes, isoflavones, neoflavonoids, oligoflavonoids, pterocarpans/pterocarpenes, and rotenone/rotenoids, was summarized through a comprehensive literature search, and their structure-activity relationship, biological activities, signaling pathways, and applications were discussed. Although the respective classes of flavonoids contained at least one chemical mimicking estrogen, the mechanisms varied, such as those with estrogenic, anti-estrogenic, non-estrogenic, and biphasic activities, and additional activities through crosstalk/bypassing, which exert biological activities through cell signaling pathways. Such mechanistic variations of estrogen action are not limited to flavonoids and are observed among other broad categories of chemicals, thus this group of chemicals can be termed as the "estrogenome". This review article focuses on the connection of estrogen action mainly between the outer and the inner environments, which represent variations of chemicals and biological activities/signaling pathways, respectively, and form the basis to understand their applications. The applications of chemicals will markedly progress due to emerging technologies, such as artificial intelligence for precision medicine, which is also true of the study of the estrogenome including estrogenic flavonoids.
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Santacroce L, Imbimbo C, Ballini A, Crocetto F, Scacco S, Cantore S, Di Zazzo E, Colella M, Jirillo E. Testicular Immunity and Its Connection with the Microbiota. Physiological and Clinical Implications in the Light of Personalized Medicine. J Pers Med 2022; 12:1335. [PMID: 36013286 PMCID: PMC9409709 DOI: 10.3390/jpm12081335] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 12/03/2022] Open
Abstract
Reproduction is a complex process, which is based on the cooperation between the endocrine-immune system and the microbiota. Testicular immunity is characterized by the so-called immune privilege, a mechanism that avoids autoimmune attacks against proteins expressed by spermatozoa. Testicular microbiota is connected with the gut microbiota, the most prevalent site of commensals inthe body. Both microbiotas take part inthe development of the immune system and protection againstpathogen invasion. Dysbiosis is caused by concurrent pathologies, such as obesity, diabetes, infections and trauma. The substitution of beneficial bacteria with pathogens may lead to destruction of spermatozoa directly or indirectly and, ultimately, to male infertility. Novel therapeutic interventions, i.e., nutritional interventions and supplementation of natural products, such as, probiotics, prebiotics, antioxidants and polyphenols, may lead to the restoration of the otherwise-impaired male reproductive potential, even if experimental and clinical results are not always concordant. In this review, the structure and immune function of the testis will be described with special reference to the blood-testisbarrier. The regulatory role of both the gut and testicular microbiota will be illustrated in health and disease, also emphasizing therapeutic attempts with natural products for the correction of male infertility, in the era of personalized medicine.
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Affiliation(s)
- Luigi Santacroce
- Interdisciplinary Department of Medicine, Section of Microbiology and Virology, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Ciro Imbimbo
- Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, University of Naples “Federico II”, 80131Naples, Italy
| | - Andrea Ballini
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
| | - Felice Crocetto
- Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, University of Naples “Federico II”, 80131Naples, Italy
| | - Salvatore Scacco
- Department of Basic Medical Sciences, Neurosciences and Sense Organs, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Stefania Cantore
- Independent Researcher, Sorriso & Benessere—Ricerca e Clinica, 70129 Bari, Italy
| | - Erika Di Zazzo
- Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy
| | - Marica Colella
- Interdisciplinary Department of Medicine, Section of Microbiology and Virology, University of Bari “Aldo Moro”, 70124 Bari, Italy
| | - Emilio Jirillo
- Interdisciplinary Department of Medicine, Section of Microbiology and Virology, University of Bari “Aldo Moro”, 70124 Bari, Italy
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Venneri MA, Franceschini E, Sciarra F, Rosato E, D'Ettorre G, Lenzi A. Human genital tracts microbiota: dysbiosis crucial for infertility. J Endocrinol Invest 2022; 45:1151-1160. [PMID: 35113404 PMCID: PMC9098539 DOI: 10.1007/s40618-022-01752-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/18/2022] [Indexed: 01/12/2023]
Abstract
Human body is colonized by trillions of microbes, influenced by several factors, both endogenous, as hormones and circadian regulation, and exogenous as, life-style habits and nutrition. The alteration of such factors can lead to microbial dysbiosis, a phenomenon which, in turn, represents a risk factor in many different pathologies including cancer, diabetes, autoimmune and cardiovascular disease, and infertility. Female microbiota dysbiosis (vaginal, endometrial, placental) and male microbiota dysbiosis (seminal fluid) can influence the fertility, determining a detrimental impact on various conditions, as pre-term birth, neonatal illnesses, and macroscopic sperm parameters impairments. Furthermore, unprotected sexual intercourse creates a bacterial exchange between partners, and, in addition, each partner can influence the microbiota composition of partner's reproductive tracts. This comprehensive overview of the effects of bacterial dysbiosis in both sexes and how partners might influence each other will allow for better personalization of infertility management.
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Affiliation(s)
- M A Venneri
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.
| | - E Franceschini
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - F Sciarra
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - E Rosato
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - G D'Ettorre
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - A Lenzi
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.
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Loutchanwoot P, Harnsoongnoen S. Microwave Microfluidic Sensor for Detection of High Equol Concentrations in Aqueous Solution. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2022; 16:244-251. [PMID: 35196242 DOI: 10.1109/tbcas.2022.3153459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This paper presents a Peano fractal geometry complementary split ring resonator (PFCSRR) loaded microstrip transmission line with a microfluidic channel for equol (EQ) sensing in a high and wide range of concentrations in aqueous solution. The proposed sensor was designed based on a CSRR loaded microstrip line with a Peano fractal in the center of a CSRR and validated through simulation and experiment. The microfluidic channel was fabricated using polydimethylsiloxane (PDMS) and installed to cover the sensing area. The free space, empty microfluidic channels, deionized (DI) water, dimethyl sulfoxide (DMSO), and various concentrations of EQ were measured by a microwave sensor through sample-filled microfluidic channels. Detection of high levels of EQ was in the concentration range of 0.01 mM - 100 mM. The materials under test (MUTs) were measured in the frequency range of 1.0 GHz-3.5 GHz based on the magnitude of the transmission coefficient (S21) and resonance frequency (Fr) at room temperature. The S21 and Fr were recorded and analyzed by logarithmic concentrations of EQ for the determinant of the correlations between EQ concentration and S21 and Fr. Principal component analysis (PCA) and K-means clustering were used to analyze and classify groups of MUTs.
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Gallucci A, Patel DC, Thai K, Trinh J, Gude R, Shukla D, Campbell SL. Gut metabolite S-equol ameliorates hyperexcitability in entorhinal cortex neurons following Theiler murine encephalomyelitis virus-induced acute seizures. Epilepsia 2021; 62:1829-1841. [PMID: 34212377 PMCID: PMC9291536 DOI: 10.1111/epi.16979] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 12/28/2022]
Abstract
Objective A growing body of evidence indicates a potential role for the gut–brain axis as a novel therapeutic target in treating seizures. The present study sought to characterize the gut microbiome in Theiler murine encephalomyelitis virus (TMEV)‐induced seizures, and to evaluate the effect of microbial metabolite S‐equol on neuronal physiology as well as TMEV‐induced neuronal hyperexcitability ex vivo. Methods We infected C57BL/6J mice with TMEV and monitored the development of acute behavioral seizures 0–7 days postinfection (dpi). Fecal samples were collected at 5–7 dpi and processed for 16S sequencing, and bioinformatics were performed with QIIME2. Finally, we conducted whole‐cell patch‐clamp recordings in cortical neurons to investigate the effect of exogenous S‐equol on cell intrinsic properties and neuronal hyperexcitability. Results We demonstrated that gut microbiota diversity is significantly altered in TMEV‐infected mice at 5–7 dpi, exhibiting separation in beta diversity in TMEV‐infected mice dependent on seizure phenotype, and lower abundance of genus Allobaculum in TMEV‐infected mice regardless of seizure phenotype. In contrast, we identified specific loss of S‐equol‐producing genus Adlercreutzia as a microbial hallmark of seizure phenotype following TMEV infection. Electrophysiological recordings indicated that exogenous S‐equol alters cortical neuronal physiology. We found that entorhinal cortex neurons are hyperexcitable in TMEV‐infected mice, and exogenous application of microbial‐derived S‐equol ameliorated this TMEV‐induced hyperexcitability. Significance Our study presents the first evidence of microbial‐derived metabolite S‐equol as a potential mechanism for alteration of TMEV‐induced neuronal excitability. These findings provide new insight for the novel role of S‐equol and the gut–brain axis in epilepsy treatment.
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Affiliation(s)
- Allison Gallucci
- Graduate Program in Translational Biology Medicine and Health, Virginia Tech, Roanoke, Virginia, USA.,Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Dipan C Patel
- Fralin Biomedical Research Institute, Virginia Polytechnic Institute and State University, Roanoke, Virginia, USA
| | - K'Ehleyr Thai
- Graduate Program in Translational Biology Medicine and Health, Virginia Tech, Roanoke, Virginia, USA.,Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Jonathan Trinh
- University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Rosalie Gude
- Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Devika Shukla
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Susan L Campbell
- Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA.,School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
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Vázquez L, Flórez AB, Rodríguez J, Mayo B. Heterologous expression of equol biosynthesis genes from Adlercreutzia equolifaciens. FEMS Microbiol Lett 2021; 368:6309895. [PMID: 34173644 PMCID: PMC8266531 DOI: 10.1093/femsle/fnab082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/29/2021] [Indexed: 12/23/2022] Open
Abstract
Equol is the isoflavone-derived metabolite with the greatest estrogenic and antioxidant activity. It is produced from daidzein by fastidious and oxygen-susceptible intestinal bacteria, which hinders their use at an industrial scale. Therefore, expressing the equol production machinery into easily-cultivable hosts would expedite the heterologous production of this compound. In this work, four genes (racemase, tdr, ddr and dzr) coding for key enzymes involved in equol production in Adlercreutzia equolifaciens DSM19450T were synthesized and cloned in a pUC-derived vector (pUC57-equol) that was introduced in Escherichia coli. Recombinant clones of E. coli produced equol in cultures supplemented with daidzein (equol precursor) and dihydrodaidzein (intermediate compound). To check whether equol genes were expressed in Gram-positive bacteria, the pUC57-equol construct was cloned into the low-copy-number vector pIL252, and the new construct (pIL252-pUC57-equol) introduced into model strains of Lacticaseibacillus casei and Lactococcus lactis. L. casei clones carrying pIL252-pUC57-equol produced a small amount of equol from dihydrodaidzein but not from daidzein, while L. lactis recombinant clones produced no equol from either of the substrates. This is the first time that A. equolifaciens equol genes have been cloned and expressed in heterologous hosts. E. coli clones harboring pUC57-equol could be used for biotechnological production of equol.
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Affiliation(s)
- Lucía Vázquez
- Departamento de Microbiología y Bioquímica, Instituto de Productos Lácteos de Asturias (IPLA), Consejo Superior de Investigaciones Científicas (CSIC), Paseo Río Linares s/n, 33300-Villaviciosa, Spain.,Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Avenida de Roma s/n, 33011-Oviedo, Spain
| | - Ana Belén Flórez
- Departamento de Microbiología y Bioquímica, Instituto de Productos Lácteos de Asturias (IPLA), Consejo Superior de Investigaciones Científicas (CSIC), Paseo Río Linares s/n, 33300-Villaviciosa, Spain.,Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Avenida de Roma s/n, 33011-Oviedo, Spain
| | - Javier Rodríguez
- Departamento de Microbiología y Bioquímica, Instituto de Productos Lácteos de Asturias (IPLA), Consejo Superior de Investigaciones Científicas (CSIC), Paseo Río Linares s/n, 33300-Villaviciosa, Spain.,Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Avenida de Roma s/n, 33011-Oviedo, Spain
| | - Baltasar Mayo
- Departamento de Microbiología y Bioquímica, Instituto de Productos Lácteos de Asturias (IPLA), Consejo Superior de Investigaciones Científicas (CSIC), Paseo Río Linares s/n, 33300-Villaviciosa, Spain.,Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Avenida de Roma s/n, 33011-Oviedo, Spain
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Zhang Y, Lu Y, Ma H, Xu Q, Wu X. Combined Exposure to Multiple Endocrine Disruptors and Uterine Leiomyomata and Endometriosis in US Women. Front Endocrinol (Lausanne) 2021; 12:726876. [PMID: 34489871 PMCID: PMC8418539 DOI: 10.3389/fendo.2021.726876] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/02/2021] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Uterine leiomyomata (UL) and endometriosis (EM) are common gynecological diseases damaging the reproductive health of fertile women. Among all the potential factors, environmental endocrine-disrupting chemicals are insufficiently addressed considering the multiple pollutants and mixture exposure. METHODS Women aged 20 to 54 years old in the National Health and Nutrition Examination Survey (NHANES) 2001-2006, having a complete measurement of ten commonly exposed endocrine-disrupting chemicals (including urinary phthalate metabolites, equol, and whole blood heavy metals) and answered questions about UL and EM were included (N=1204). Multivariable logistic regression model, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models were implemented to analyze the combined effect of chemicals on the overall association with UL and EM. RESULTS In single chemical analysis, equol (OR: 1.90, 95% CI: 1.11, 3.27) and mercury (Hg) (OR: 1.91, 95% CI: 1.14, 3.25) were found positively associated with UL in tertile 3 vs. tertile 1. In WQS regression and BKMR models, the significant positive association between WQS index and UL (OR: 2.54, 95% CI: 1.52, 4.29) was identified and the positive relationship between equol and Hg exposure and UL were further verified. Besides, the mixture evaluation models (WQS and BKMR) also found MEHP negatively associated with UL. Although none of the single chemicals in tertile 3 were significantly associated with EM, the WQS index had a marginally positive association with EM (OR: 2.01, 95% CI: 0.98, 4.15), and a significant positive association was identified in subanalysis with participants restricted to premenopausal women (OR: 2.18, 95% CI: 1.03, 4.70). MIBP and MBzP weighted high in model of EM and MEHP weighted the lowest. CONCLUSION Comparing results from these three statistical models, the associations between equol, Hg, and MEHP exposure with UL as well as the associations of MIBP, MBzP, and MEHP exposure with EM warrant further research.
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Affiliation(s)
- Yuqing Zhang
- Department of Women Health Care, Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Yingying Lu
- Department of Obstetrics and Gynecology, Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Huiyuan Ma
- Department of Obstetrics and Gynecology, Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Qing Xu
- Department of Obstetrics and Gynecology, Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
- *Correspondence: Xiaoli Wu, ; Qing Xu,
| | - Xiaoli Wu
- Department of Women Health Care, Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
- *Correspondence: Xiaoli Wu, ; Qing Xu,
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Draft Genome Sequence of Adlercreutzia equolifaciens IPLA 37004, a Human Intestinal Strain That Does Not Produce Equol from Daidzein. Microbiol Resour Announc 2020; 9:9/8/e01537-19. [PMID: 32079634 PMCID: PMC7033271 DOI: 10.1128/mra.01537-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Equol is an intestinal bacterial metabolite derived from the isoflavone daidzein and has beneficial health effects. Most equol producers belong to the family Coriobacteriaceae, which includes species such as Adlercreutzia equolifaciens. Here, we report the draft genome sequence of A. equolifaciens IPLA 37004, a human isolate that does not produce equol. Equol is an intestinal bacterial metabolite derived from the isoflavone daidzein and has beneficial health effects. Most equol producers belong to the family Coriobacteriaceae, which includes species such as Adlercreutzia equolifaciens. Here, we report the draft genome sequence of A. equolifaciens IPLA 37004, a human isolate that does not produce equol.
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Montalesi E, Cipolletti M, Cracco P, Fiocchetti M, Marino M. Divergent Effects of Daidzein and its Metabolites on Estrogen-Induced Survival of Breast Cancer Cells. Cancers (Basel) 2020; 12:cancers12010167. [PMID: 31936631 PMCID: PMC7017042 DOI: 10.3390/cancers12010167] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 01/13/2023] Open
Abstract
Although soy consumption is associated with breast cancer prevention, the low bioavailability and the extensive metabolism of soy-active components limit their clinical application. Here, the impact of daidzein (D) and its metabolites on estrogen-dependent anti-apoptotic pathway has been evaluated in breast cancer cells. In estrogen receptor α-positive breast cancer cells treated with D and its metabolites, single or in mixture, ERα activation and Neuroglobin (NGB) levels, an anti-apoptotic estrogen/ERα-inducible protein, were evaluated. Moreover, the apoptotic cascade activation, as well as the cell number after stimulation was assessed in the absence/presence of paclitaxel to determine the compound effects on cell susceptibility to a chemotherapeutic agent. Among the metabolites, only D-4'-sulfate maintains the anti-estrogenic effect of D, reducing the NGB levels and rendering breast cancer cells more prone to the paclitaxel treatment, whereas other metabolites showed estrogen mimetic effects, or even estrogen independent effects. Intriguingly, the co-stimulation of D and gut metabolites strongly reduced D effects. The results highlight the important and complex influence of metabolic transformation on isoflavones physiological effects and demonstrate the need to take biotransformation into account when assessing the potential health benefits of consumption of soy isoflavones in cancer.
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Sorkin BC, Kuszak AJ, Bloss G, Fukagawa NK, Hoffman FA, Jafari M, Barrett B, Brown PN, Bushman FD, Casper S, Chilton FH, Coffey CS, Ferruzzi MG, Hopp DC, Kiely M, Lakens D, MacMillan JB, Meltzer DO, Pahor M, Paul J, Pritchett-Corning K, Quinney SK, Rehermann B, Setchell KD, Sipes NS, Stephens JM, Taylor DL, Tiriac H, Walters MA, Xi D, Zappalá G, Pauli GF. Improving natural product research translation: From source to clinical trial. FASEB J 2020; 34:41-65. [PMID: 31914647 PMCID: PMC7470648 DOI: 10.1096/fj.201902143r] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/12/2019] [Accepted: 10/21/2019] [Indexed: 12/28/2022]
Abstract
While great interest in health effects of natural product (NP) including dietary supplements and foods persists, promising preclinical NP research is not consistently translating into actionable clinical trial (CT) outcomes. Generally considered the gold standard for assessing safety and efficacy, CTs, especially phase III CTs, are costly and require rigorous planning to optimize the value of the information obtained. More effective bridging from NP research to CT was the goal of a September, 2018 transdisciplinary workshop. Participants emphasized that replicability and likelihood of successful translation depend on rigor in experimental design, interpretation, and reporting across the continuum of NP research. Discussions spanned good practices for NP characterization and quality control; use and interpretation of models (computational through in vivo) with strong clinical predictive validity; controls for experimental artefacts, especially for in vitro interrogation of bioactivity and mechanisms of action; rigorous assessment and interpretation of prior research; transparency in all reporting; and prioritization of research questions. Natural product clinical trials prioritized based on rigorous, convergent supporting data and current public health needs are most likely to be informative and ultimately affect public health. Thoughtful, coordinated implementation of these practices should enhance the knowledge gained from future NP research.
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Affiliation(s)
- Barbara C. Sorkin
- Office of Dietary Supplements, National Institutes of Health (NIH), Bethesda, MD, US
| | - Adam J. Kuszak
- Office of Dietary Supplements, National Institutes of Health (NIH), Bethesda, MD, US
| | - Gregory Bloss
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, US
| | | | | | | | | | - Paula N. Brown
- British Columbia Institute of Technology, Burnaby, British Columbia, Canada
| | | | - Steven Casper
- Office of Dietary Supplement Programs, Center for Food Safety and Applied Nutrition, Food and Drug Administration (FDA), Hyattsville, MD, US
| | - Floyd H. Chilton
- Department of Nutritional Sciences and the BIO5 Institute, University of Arizona, Tucson, AZ, US
| | | | - Mario G. Ferruzzi
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, US
| | - D. Craig Hopp
- National Center for Complementary and Integrative Health, NIH, Bethesda, MD, US
| | - Mairead Kiely
- Cork Centre for Vitamin D and Nutrition Research, School of Food and Nutritional Sciences, University College Cork, Ireland
| | - Daniel Lakens
- Eindhoven University of Technology, Eindhoven, Netherlands
| | | | | | | | - Jeffrey Paul
- Drexel Graduate College of Biomedical Sciences, College of Medicine, Evanston, IL, US
| | | | | | - Barbara Rehermann
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, US
| | | | - Nisha S. Sipes
- National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC, US
| | | | | | - Hervé Tiriac
- University of California, San Diego, La Jolla, CA, US]
| | - Michael A. Walters
- Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN, US
| | - Dan Xi
- Office of Cancer Complementary and Alternative Medicine, National Cancer Institute, NIH, Shady Grove, MD, US
| | | | - Guido F. Pauli
- CENAPT and PCRPS, University of Illinois at Chicago College of Pharmacy, Chicago, IL, US
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Song H, Hughes JR, Turner RT, Iwaniec UT, Doerge DR, Helferich WG. (±)-Equol does not interact with genistein on estrogen-dependent breast tumor growth. Food Chem Toxicol 2019; 136:110979. [PMID: 31786350 DOI: 10.1016/j.fct.2019.110979] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 11/12/2019] [Accepted: 11/14/2019] [Indexed: 12/13/2022]
Abstract
Equol (EQ) is a prominent microbial metabolite of the soy isoflavone, daidzein, with estrogen-like properties. The major soy isoflavone, genistein (GEN), stimulated growth of estrogen-dependent breast cancer (EDBC) cells in vitro and tumor growth in vivo but EQ did not. To understand possible interactions of EQ and GEN on EDBC, EQ was used with GEN in combination in vitro and in vivo. Effects of EQ, GEN and EQ + GEN were evaluated using MCF-7 and T47D EDBC. Ovariectomized athymic mice were used as a model for in vivo tumor growth. Dietary EQ had no effect on MCF-7 tumor growth and the absence of effect was confirmed using a T47D EDBC in vivo model. EQ alone or in combination with GEN increased EDBC cell proliferation in vitro. EQ alone neither stimulated EDBC tumor growth in vivo at various doses nor suppressed tumor growth induced by dietary GEN. In summary, EQ has similar estrogenic effect as GEN in vitro but does not interact with GEN on EDBC tumor growth. Based on the evidence presented here, dietary EQ is unlikely to have estrogenic effects in vivo.
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Affiliation(s)
- Huaxin Song
- School of Nursing, Texas Tech University Health Sciences Center, Lubbock, TX, 79430, USA; Department of Food Science and Human Nutrition, University of Illinois Urbana-Champaign, 61801, USA
| | - Jennifer R Hughes
- Department of Food Science and Human Nutrition, University of Illinois Urbana-Champaign, 61801, USA
| | - Russell T Turner
- Skeletal Biology Laboratory, School of Biological and Population Health Science, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Urszula T Iwaniec
- Skeletal Biology Laboratory, School of Biological and Population Health Science, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, 97331, USA
| | - Daniel R Doerge
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food & Drug Administration, Jefferson, AR, 72079, USA
| | - William G Helferich
- Department of Food Science and Human Nutrition, University of Illinois Urbana-Champaign, 61801, USA.
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Weger BD, Rawashdeh O, Gachon F. At the Intersection of Microbiota and Circadian Clock: Are Sexual Dimorphism and Growth Hormones the Missing Link to Pathology? Bioessays 2019; 41:e1900059. [DOI: 10.1002/bies.201900059] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/28/2019] [Indexed: 12/15/2022]
Affiliation(s)
- Benjamin D. Weger
- Institute of Bioengineering, School of Life SciencesEcole Polytechnique Fédérale de LausanneLausanne CH‐1015 Switzerland
| | - Oliver Rawashdeh
- School of Biomedical Science, Faculty of MedicineThe University of QueenslandSt. Lucia QLD‐4072 Australia
| | - Frédéric Gachon
- Institute for Molecular BioscienceThe University of QueenslandSt. Lucia QLD‐4072 Australia
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13
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Borgert CJ, Matthews JC, Baker SP. Human-relevant potency threshold (HRPT) for ERα agonism. Arch Toxicol 2018; 92:1685-1702. [PMID: 29632997 PMCID: PMC5962616 DOI: 10.1007/s00204-018-2186-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 03/13/2018] [Indexed: 11/30/2022]
Abstract
The European Commission has recently proposed draft criteria for the identification of endocrine disrupting chemicals (EDCs) that pose a significant hazard to humans or the environment. Identifying and characterizing toxic hazards based on the manner by which adverse effects are produced rather than on the nature of those adverse effects departs from traditional practice and requires a proper interpretation of the evidence regarding the chemical’s ability to produce physiological effect(s) via a specific mode of action (MoA). The ability of any chemical to produce a physiological effect depends on its pharmacokinetics and the potency by which it acts via the various MoAs that can lead to the particular effect. A chemical’s potency for a specific MoA—its mechanistic potency—is determined by two properties: (1) its affinity for the functional components that comprise the MoA, i.e., its specific receptors, enzymes, transporters, transcriptional elements, etc., and (2) its ability to alter the functional state of those components (activity). Using the agonist MoA via estrogen receptor alpha, we illustrate an empirical method for determining a human-relevant potency threshold (HRPT), defined as the minimum level of mechanistic potency necessary for a chemical to be able to act via a particular MoA in humans. One important use for an HRPT is to distinguish between chemicals that may be capable of, versus those likely to be incapable of, producing adverse effects in humans via the specified MoA. The method involves comparing chemicals that have different ERα agonist potencies with the ability of those chemicals to produce ERα-mediated agonist responses in human clinical trials. Based on this approach, we propose an HRPT for ERα agonism of 1E-04 relative to the potency of the endogenous estrogenic hormone 17β-estradiol or the pharmaceutical estrogen, 17α-ethinylestradiol. This approach provides a practical way to address Hazard Identification according to the draft criteria for identification of EDCs recently proposed by the European Commission.
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Affiliation(s)
- Christopher J Borgert
- Applied Pharmacology and Toxicology, Inc. and CEHT, Univ. FL College of Vet. Med., Gainesville, FL, USA.
| | - John C Matthews
- University of Mississippi School of Pharmacy, University, MS, USA
| | - Stephen P Baker
- Department of Pharmacology and Therapeutics, University of Florida College of Medicine, Gainesville, FL, USA
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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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15
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Tousen Y, Ishiwata H, Ishimi Y, Ikegami S. Equol, a Metabolite of Daidzein, Is More Efficient than Daidzein for Bone Formation in Growing Female Rats. Phytother Res 2015; 29:1349-1354. [PMID: 26096577 DOI: 10.1002/ptr.5387] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Revised: 05/12/2015] [Accepted: 05/14/2015] [Indexed: 11/10/2022]
Abstract
Few studies have examined the effects of isoflavones and particularly equol, a metabolite of the isoflavone daidzein, on bone formation during the growth period in animals. The present study investigated the effects of orally administered daidzein or equol on bone formation and bone mineral density in growing female rats. Female Sprague-Dawley rats, aged 3 weeks, were divided into four groups (n = 8 per group) as follows: rats were orally administered a corn oil, 8 mg/day of daidzein, 4 mg/day of equol or 8 mg/day of equol in corn oil for 4 weeks. Daidzein and equol increased the bone mineral density of growing female rats by stimulating bone formation without exhibiting a substantial effect on the weight of their reproductive organs. Bone growth caused by increased bone mineralizing surface and bone formation rate in rats administered with equol was approximately twice that of rats administered with daidzein. These results suggest that equol might be more efficient than daidzein for bone formation in growing female rats. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Yuko Tousen
- Department of Food Function and Labeling, National Institute of Health and Nutrition, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8636, Japan
| | - Hajimu Ishiwata
- Department of Human Nutrition, Seitoku University, 550 Iwase, Mastudo, Chiba, 271-8555, Japan
| | - Yoshiko Ishimi
- Department of Food Function and Labeling, National Institute of Health and Nutrition, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8636, Japan
| | - Sachie Ikegami
- Department of Home Economics, Otsuma Woman's University, 12 Sanbancho, Chiyoda-ku, Tokyo, 102-8357, Japan
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16
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Gong P, Madak-Erdogan Z, Li J, Cheng J, Greenlief CM, Helferich W, Katzenellenbogen JA, Katzenellenbogen BS. Transcriptomic analysis identifies gene networks regulated by estrogen receptor α (ERα) and ERβ that control distinct effects of different botanical estrogens. NUCLEAR RECEPTOR SIGNALING 2014; 12:e001. [PMID: 25363786 PMCID: PMC4193135 DOI: 10.1621/nrs.12001] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 04/28/2014] [Accepted: 05/13/2014] [Indexed: 12/31/2022]
Abstract
The estrogen receptors (ERs) ERα and ERβ mediate the actions of endogenous estrogens as well as those of botanical estrogens (BEs) present in plants. BEs are ingested in the diet and also widely consumed by postmenopausal women as dietary supplements, often as a substitute for the loss of endogenous estrogens at menopause. However, their activities and efficacies, and similarities and differences in gene expression programs with respect to endogenous estrogens such as estradiol (E2) are not fully understood. Because gene expression patterns underlie and control the broad physiological effects of estrogens, we have investigated and compared the gene networks that are regulated by different BEs and by E2. Our aim was to determine if the soy and licorice BEs control similar or different gene expression programs and to compare their gene regulations with that of E2. Gene expression was examined by RNA-Seq in human breast cancer (MCF7) cells treated with control vehicle, BE or E2. These cells contained three different complements of ERs, ERα only, ERα+ERβ, or ERβ only, reflecting the different ratios of these two receptors in different human breast cancers and in different estrogen target cells. Using principal component, hierarchical clustering, and gene ontology and interactome analyses, we found that BEs regulated many of the same genes as did E2. The genes regulated by each BE, however, were somewhat different from one another, with some genes being regulated uniquely by each compound. The overlap with E2 in regulated genes was greatest for the soy isoflavones genistein and S-equol, while the greatest difference from E2 in gene expression pattern was observed for the licorice root BE liquiritigenin. The gene expression pattern of each ligand depended greatly on the cell background of ERs present. Despite similarities in gene expression pattern with E2, the BEs were generally less stimulatory of genes promoting proliferation and were more pro-apoptotic in their gene regulations than E2. The distinctive patterns of gene regulation by the individual BEs and E2 may underlie differences in the activities of these soy and licorice-derived BEs in estrogen target cells containing different levels of the two ERs.
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Affiliation(s)
| | | | - Jilong Li
- Botanical Research Center, University of Missouri, Columbia, MO 65211
| | - Jianlin Cheng
- Botanical Research Center, University of Missouri, Columbia, MO 65211
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17
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Equol elicits estrogenic activities via PI3K/akt pathway in the estrogen receptor-positive MCF-7 cells. Mol Cell Toxicol 2014. [DOI: 10.1007/s13273-014-0032-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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18
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Neese SL, Pisani SL, Doerge DR, Helferich WG, Sepehr E, Chittiboyina AG, Rotte SCK, Smillie TJ, Khan IA, Korol DL, Schantz SL. The effects of dietary treatment with S-equol on learning and memory processes in middle-aged ovariectomized rats. Neurotoxicol Teratol 2014; 41:80-8. [PMID: 24368316 PMCID: PMC3943933 DOI: 10.1016/j.ntt.2013.12.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 11/22/2013] [Accepted: 12/17/2013] [Indexed: 01/18/2023]
Abstract
The use of over-the-counter botanical estrogens containing isolated soy isoflavones, including genistein and daidzein, has become a popular alternative to traditional hormone therapies. Menopausal women use these products as an aide in healthy aging, including for the maintenance of cognitive function. The safety and efficacy of many of these commercial preparations remain unknown. Previous research in our lab found that treatment of ovariectomized (OVX) female Long-Evans rats with genistein impaired working memory in an operant delayed spatial alternation (DSA) task and response learning in a plus-maze, but enhanced place learning assessed in the plus-maze. The present study further examined the effects of isolated isoflavones on working memory and place learning by treating middle-aged (12-13 month old) OVX female Long-Evans rats with S-equol, the exclusive enantiomer produced by metabolism of daidzein in the mammalian gut. S-equol binds selectively to ERβ with an affinity similar to that of genistein but has low transcriptional potency. For DSA testing, S-equol at 1.94, 0.97 mg, or 0mg (sucrose control) was orally administered to animals daily, 30 min before behavioral testing, and again both 4 and 8 hours after the first treatment. Rats were tested on the DSA task following the first, morning dose. For place learning, rats received 0.97 mg S-equol every 4 hours during the light portion of the cycle beginning 48 hours prior to behavioral testing (total exposure 8.7 mg S-equol). S-equol treatment was largely without effect on the DSA and place learning tasks. This is the first study to test the behavioral effects of isolated S-equol in OVX rodents, and shows that, unlike genistein or estradiol, repeated daily treatment with this isoflavone metabolite does not alter learning and memory processes in middle-aged OVX rats.
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Affiliation(s)
- Steven L Neese
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, 2001S. Lincoln Avenue, Urbana, IL 61802, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, 505 South Goodwin Avenue, Urbana, IL 61801, USA; Department of Psychology and Neuroscience, Baldwin Wallace University, 275 Eastland Road, Berea, OH 44017, USA.
| | - Samantha L Pisani
- Neuroscience Program, University of Illinois at Urbana-Champaign, 505 South Goodwin Avenue, Urbana, IL 61801, USA.
| | - Daniel R Doerge
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079-9502, USA.
| | - William G Helferich
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, 905S Goodwin Avenue, Urbana, IL 61801, USA.
| | - Estatira Sepehr
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079-9502, USA.
| | - Amar G Chittiboyina
- National Center for Natural Product Research, University of Mississippi, 3011 Thad Cochran Research Center, University, MS 38677, USA.
| | - Sateesh Chandra Kumar Rotte
- National Center for Natural Product Research, University of Mississippi, 3011 Thad Cochran Research Center, University, MS 38677, USA.
| | - Troy J Smillie
- National Center for Natural Product Research, University of Mississippi, 3011 Thad Cochran Research Center, University, MS 38677, USA.
| | - Ikhlas A Khan
- National Center for Natural Product Research, University of Mississippi, 3011 Thad Cochran Research Center, University, MS 38677, USA.
| | - Donna L Korol
- Neuroscience Program, University of Illinois at Urbana-Champaign, 505 South Goodwin Avenue, Urbana, IL 61801, USA; Department of Biology, Syracuse University, 107 College Place, Syracuse, NY 13244, USA.
| | - Susan L Schantz
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, 2001S. Lincoln Avenue, Urbana, IL 61802, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, 505 South Goodwin Avenue, Urbana, IL 61801, USA.
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19
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Loutchanwoot P, Srivilai P, Jarry H. Lack of anti-androgenic effects of equol on reproductive neuroendocrine function in the adult male rat. Horm Behav 2014; 65:22-31. [PMID: 24211351 DOI: 10.1016/j.yhbeh.2013.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 10/29/2013] [Accepted: 10/31/2013] [Indexed: 10/26/2022]
Abstract
Equol (EQ), a metabolite of the soy isoflavone daidzein, has well known estrogenic properties. Data from animal studies suggested that EQ may act also as an anti-androgen. However, data regarding how EQ may affect brain functions like the regulation of neuroendocrine activity and reproductive outcomes in adult male rats are still lacking. We therefore investigated the effects of EQ on sex-steroid regulated gene expression in the brain [medial preoptic area/anterior hypothalamus (MPOA/AH) and medial basal hypothalamus/median eminence (MBH/ME)], pituitary, and prostate as a reference androgen-dependent organ. Furthermore reproductive outcomes were evaluated. The anti-androgen flutamide (FLUT) served as reference compound. Male rats (n=12 per group) were treated by gavage for 5 days with either EQ (100 or 250 mg/kgBW/day), or FLUT 100 mg/kgBW/day. All vehicle- and EQ-treated males showed successful reproductive outcomes, whereas FLUT-exposed males had severe reproductive impairments resulted in infertility. FLUT decreased relative weights of prostate, seminal vesicles and epididymides, and increased serum levels of luteinizing hormone, follicle-stimulating hormone, testosterone and 5α-dihydrotestosterone without altering prolactin levels, whereas EQ exerted opposite effects. Both EQ and FLUT decreased gonadotropin releasing hormone (GnRH) expression in the MPOA/AH. Only FLUT upregulated levels of GnRH receptor expression both in the MBH/ME and pituitary. While EQ downregulated the hypothalamic ERα and ERβ expressions, but FLUT did not. In the prostate, only FLUT upregulated both ERα and AR mRNA expression levels. Taken together, our findings are the first data that EQ did not induce anti-androgenic effects on brain, prostate and male reproductive parameters, however, estrogenic neuroendocrine and reproductive effects of EQ were observed.
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Affiliation(s)
- Panida Loutchanwoot
- Department of Biology, Faculty of Science, Mahasarakham University, Khamriang Sub-district, Kantarawichai District, Mahasarakham Province 44150, Thailand.
| | - Prayook Srivilai
- Department of Biology, Faculty of Science, Mahasarakham University, Khamriang Sub-district, Kantarawichai District, Mahasarakham Province 44150, Thailand.
| | - Hubertus Jarry
- Department of Endocrinology, University Medical Center Göttingen, Robert-Koch-Strasse 40, D-37075 Göttingen, Germany.
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20
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Cooke PS, Spencer TE, Bartol FF, Hayashi K. Uterine glands: development, function and experimental model systems. Mol Hum Reprod 2013; 19:547-58. [PMID: 23619340 DOI: 10.1093/molehr/gat031] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Development of uterine glands (adenogenesis) in mammals typically begins during the early post-natal period and involves budding of nascent glands from the luminal epithelium and extensive cell proliferation in these structures as they grow into the surrounding stroma, elongate and mature. Uterine glands are essential for pregnancy, as demonstrated by the infertility that results from inhibiting the development of these glands through gene mutation or epigenetic strategies. Several genes, including forkhead box A2, beta-catenin and members of the Wnt and Hox gene families, are implicated in uterine gland development. Progestins inhibit uterine epithelial proliferation, and this has been employed as a strategy to develop a model in which progestin treatment of ewes for 8 weeks from birth produces infertile adults lacking uterine glands. More recently, mouse models have been developed in which neonatal progestin treatment was used to permanently inhibit adenogenesis and adult fertility. These studies revealed a narrow and well-defined window in which progestin treatments induced permanent infertility by impairing neonatal gland development and establishing endometrial changes that result in implantation defects. These model systems are being utilized to better understand the molecular mechanisms underlying uterine adenogenesis and endometrial function. The ability of neonatal progestin treatment in sheep and mice to produce infertility suggests that an approach of this kind may provide a contraceptive strategy with application in other species. Recent studies have defined the temporal patterns of adenogenesis in uteri of neonatal and juvenile dogs and work is underway to determine whether neonatal progestin or other steroid hormone treatments might be a viable contraceptive approach in this species.
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Affiliation(s)
- Paul S Cooke
- Department of Physiological Sciences, University of Florida, Gainesville, FL 32610, USA.
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21
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Loutchanwoot P, Srivilai P, Jarry H. Effects of the natural endocrine disruptor equol on the pituitary function in adult male rats. Toxicology 2012; 304:69-75. [PMID: 23220561 DOI: 10.1016/j.tox.2012.11.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 11/09/2012] [Accepted: 11/28/2012] [Indexed: 11/26/2022]
Abstract
Equol (EQ), a potent biologically active metabolite of the soy isoflavone daidzein, interacts with estrogen receptors (ERs), however, as suggested recently, EQ may also exert anti-androgenic actions in androgen regulated tissues like prostate and seminal vesicles in adult male rats. However, data regarding a putative anti-androgenic activity of EQ on pituitary function in male individuals are still lacking. Therefore, we investigated the effects of EQ on androgen- and estrogen-regulated gene expressions in the pituitary and circulating luteinizing hormone (LH) and prolactin (PRL) levels in adult male rats. 3-Month-old male Sprague-Dawley rats (n=12 per group) were treated by gavage for 5 days with either EQ (100 and 250 mg/kg BW/day) or vehicle olive oil (1 ml/rat/day). As reference compound, the pure anti-androgenic drug flutamide (FLUT) was employed at a dose of 100 mg/kg BW/day. At day 5, animals were sacrificed. Levels of pituitary hormones and gene expression were measured by radioimmunoassays and quantitative TaqMan(®) real-time reverse transcription polymerase chain reaction, respectively. The present findings revealed that the pituitary mechanisms involved in the effects of EQ and FLUT were different due to the opposite changes in the mRNA expression levels of estrogen receptor subtype alpha (ERα)-, truncated estrogen receptor product-1 (TERP-1)- and -2 (TERP-2)-, gonadotropin releasing hormone receptor (GnRH receptor)-, beta-subunit of LH (LHβ)-, and gonadotropin alpha subunit (α-subunit) genes. EQ displayed typical ER-agonistic actions as shown by the significant increases in ERα-, TERP-1/-2 mRNA expressions and serum PRL levels along with the significant reduction in serum LH levels, whereas FLUT exerted opposite effects on gonadotropin secretion and expression. Taken together, our findings are the first in vivo data that upon sub-acute oral exposure of EQ show an estrogenic effect on reproductive endocrine activity of the pituitary in adult male rats. However, EQ did not exert anti-androgenic effects on male rat pituitary function as observed at the levels of mRNA expression of androgen- and estrogen-regulated genes and circulating pituitary hormones.
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Affiliation(s)
- Panida Loutchanwoot
- Department of Biology, Faculty of Science, Mahasarakham University, Khamriang Sub-district, Kantarawichai District, Mahasarakham Province 44150, Thailand.
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22
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Galluzzo P, Marino M. Nutritional flavonoids impact on nuclear and extranuclear estrogen receptor activities. GENES AND NUTRITION 2012; 1:161-76. [PMID: 18850212 DOI: 10.1007/bf02829966] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 04/30/2006] [Indexed: 12/12/2022]
Abstract
Flavonoids are a large group of nonnutrient compounds naturally produced from plants as part of their defence mechanisms against stresses of different origins. They emerged from being considered an agricultural oddity only after it was observed that these compounds possess a potential protective function against several human degenerative diseases. This has led to recommending the consumption of food containing high concentrations of flavonoids, which at present, especially as soy isoflavones, are even available as overthecounter nutraceuticals. The increased use of flavonoids has occurred even though their mechanisms are not completely understood, in particular those involving the flavonoid impact on estrogen signals. In fact, most of the human health protective effects of flavonoids are described either as estrogenmimetic, or as antiestrogenic, while others do not involve estrogen signaling at all. Thus, the same molecule is reported as an endocrine disruptor, an estrogen mimetic or as an antioxidant without estrogenic effects. This is due in part to the complexity of the estrogen mechanism, which is conducted by different pathways and involves two different receptor isoforms. These pathways can be modulated by flavonoids and should be considered for a reliable evaluation of flavonoid, both estrogenicity and antiestrogenicity, and for a correct prediction of their effects on human health.
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Affiliation(s)
- Paola Galluzzo
- Department of Biology, University "Roma Tre", Viale G. Marconi 446, I-00146, Roma, Italy
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23
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Dewi FN, Wood CE, Lampe JW, Hullar MAJ, Franke AA, Golden DL, Adams MR, Cline JM. Endogenous and exogenous equol are antiestrogenic in reproductive tissues of apolipoprotein e-null mice. J Nutr 2012; 142:1829-35. [PMID: 22933749 PMCID: PMC3442795 DOI: 10.3945/jn.112.161711] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 05/01/2012] [Accepted: 07/25/2012] [Indexed: 02/05/2023] Open
Abstract
Equol is an isoflavone (IF) metabolite produced by intestinal microbiota in a subset of people consuming dietary soy. Equol producers may show different responses to soy foods and phenotypes related to cancer risk. Here, we assessed the effects of soy IF, endogenous microbial equol production, and dietary racemic equol in a 3 × 2 × 2 factorial experiment using gnotobiotic apoE-null mice (n = 9-11/group/sex). At age 3-6 wk, equol-producing microbiota were introduced to one-half of the colony (n = 122). At age 6 wk, mice were randomized to receive a diet that contained 1 of 3 protein sources: casein and lactalbumin, alcohol-washed soy protein (low IF), and intact soy protein (high IF), with total IF amounts of 0, 42, and 566 mg/kg diet, respectively. One-half of each diet group also received racemic equol (291 mg/kg diet). After 16 wk of dietary treatment, serum isoflavonoid profiles varied with sex, soy IF amount, and intestinal microbiota status. There were no treatment effects on tissues of male mice. In females, reproductive tissue phenotypes differed by equol-producing ability (i.e., microbiota status) but not dietary equol or IF content. Equol producers had lower uterine weight, vaginal epithelial thickness, total uterine area, endometrial area, and endometrial luminal epithelial height compared with nonproducers (P < 0.05 for all), with an association between microbiota status and estrous cycle (P > chi-square = 0.03). Exogenous equol reduced expression of progesterone receptor (PGR) and the proliferation marker Ki67 (P < 0.0001) in vaginal epithelium and endometrium; for endogenous equol, only PGR was reduced (P < 0.0005). Our findings indicate that equol diminishes estrogen-dependent tissue responses in apoE-null mice.
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Affiliation(s)
- Fitriya N. Dewi
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston Salem, NC
| | - Charles E. Wood
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston Salem, NC
| | | | | | - Adrian A. Franke
- Cancer Biology Program, University of Hawaii Cancer Center, Honolulu, HI
| | - Deborah L. Golden
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston Salem, NC
| | - Michael R. Adams
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston Salem, NC
| | - J. Mark Cline
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston Salem, NC
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Toxicokinetics and lack of uterotropic effect of orally administered S-equol. Food Chem Toxicol 2012; 50:1741-8. [PMID: 22406328 DOI: 10.1016/j.fct.2012.02.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 02/03/2012] [Accepted: 02/21/2012] [Indexed: 11/21/2022]
Abstract
S-equol is a natural product that is produced by the microbial biotransformation of daidzein, an isoflavone found in soy. Evidence suggests that the health benefits of soy may be related to one's ability to produce S-equol, thus S-equol is being developed for the treatment of vasomotor symptoms in postmenopausal women. The toxicokinetics of S-equol were evaluated in Sprague-Dawley rats and cynomolgus monkeys; S-equol was rapidly absorbed with C(max) occurring between 0.5 h and 1.0 h in the rat and 3h in the monkey. AUC was linear over the doses tested with no differences between male and female animals. Conjugated S-equol was the major metabolite in plasma with less than 1% present as the unconjugated form. S-equol showed a weak induction of liver cytochrome P450s in vivo, and did not significantly inhibit the major human cytochrome P450s in vitro. S-equol was highly protein bound (>95%) in rat, monkey and man in a concentration-independent manner. Orally administered S-equol did not significantly change uterine weight or morphology in either the rat or monkey even at the highest doses tested. These studies show that S-equol has pharmacokinetic parameters suitable for drug development with a low potential for uterotropic effects.
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25
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Impact of perinatal exposure to equol enantiomers on reproductive development in rodents. Reprod Toxicol 2011; 32:33-42. [PMID: 21620954 DOI: 10.1016/j.reprotox.2011.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 04/15/2011] [Accepted: 05/12/2011] [Indexed: 11/22/2022]
Abstract
There is now considerable interest in the intestinally derived soy isoflavone metabolite, equol, which occurs in the enantiomeric forms, S-(-)equol and R-(+)equol, both differing in biological actions. Little is known about effects of either enantiomer on reproductive development, yet such knowledge is fundamental because of the recent commercialization of S-(-)equol as a dietary supplement. S-(-)equol and R-(+)equol were therefore investigated to determine their effects on reproductive development and fertility in the Sprague-Dawley rat. Neither enantiomer affected fertility, number of litters produced, number of pups per litter, number of male and female pups born, birth weight, anogenital distance, testicular descent or vaginal opening. Histological analysis showed no major abnormalities in ovary, testis, prostate or seminal vesicle tissue with dietary exposure to S-(-)equol or R-(+)equol, but both enantiomers triggered hyperplasia of uterine tissue. With R-(+)equol this stimulatory effect subsided after exposure was discontinued, but the effect of S-(-)equol was prolonged.
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Nielsen TS, Purup S, Wärri A, Godschalk RW, Hilakivi-Clarke L. Effects of maternal exposure to cow's milk high or low in isoflavones on carcinogen-induced mammary tumorigenesis among rat offspring. Cancer Prev Res (Phila) 2011; 4:694-701. [PMID: 21467133 DOI: 10.1158/1940-6207.capr-10-0220] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We investigated whether maternal exposure during pregnancy to cow's milk containing endogenous estrogens and insulin-like growth factor 1 (IGF-1) and either high or low levels of isoflavones from dietary legumes (HIM and LIM, respectively) affected carcinogen-induced mammary carcinogenesis in female rat offspring. Pregnant Sprague-Dawley rats were given HIM, LIM, or tap water (control) from gestational day (GD) 11 until birth; hereafter all rats received tap water. Mammary tumorigenesis was induced by administrating 7,12-dimethylbenz[a]anthracene (DMBA) on postnatal day 50. No differences in maternal serum estradiol (P = 0.19) and IGF-1 levels (P = 0.15) at GD 19 or birth weight among the milk and water groups were seen, but estradiol, and IGF-1 levels and birth weight were numerically higher in the LIM group than in the HIM group. Puberty onset occurred earlier in the LIM offspring than in controls (P = 0.03). Although the high isoflavone content seemed to prevent the effect on circulating estradiol and IGF-1 levels and advanced puberty onset seen in the LIM group, HIM increased DMBA-DNA adducts in the mammary gland and tended to increase mammary tumorigenesis. In contrast, offspring exposed to LIM in utero, did not exhibit increased breast cancer risk, despite having higher estradiol and IGF-1 environment and consequently earlier puberty onset. These results indicate that the phytochemical content in the cow's milk, consumed by a pregnant dam, determines how milk affects the offspring.
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Affiliation(s)
- Tina Skau Nielsen
- Department of Animal Health and Bioscience, Faculty of Agricultural Sciences, Aarhus University, Tjele, Denmark.
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Gautam AK, Bhargavan B, Tyagi AM, Srivastava K, Yadav DK, Kumar M, Singh A, Mishra JS, Singh AB, Sanyal S, Maurya R, Manickavasagam L, Singh SP, Wahajuddin W, Jain GK, Chattopadhyay N, Singh D. Differential effects of formononetin and cladrin on osteoblast function, peak bone mass achievement and bioavailability in rats. J Nutr Biochem 2011; 22:318-27. [DOI: 10.1016/j.jnutbio.2010.02.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 02/12/2010] [Accepted: 02/18/2010] [Indexed: 11/15/2022]
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Synthetic analogs of daidzein, having more potent osteoblast stimulating effect. Bioorg Med Chem Lett 2011; 21:677-81. [DOI: 10.1016/j.bmcl.2010.12.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Revised: 11/08/2010] [Accepted: 12/02/2010] [Indexed: 11/21/2022]
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Ma Y, Sullivan JC, Schreihofer DA. Dietary genistein and equol (4′, 7 isoflavandiol) reduce oxidative stress and protect rats against focal cerebral ischemia. Am J Physiol Regul Integr Comp Physiol 2010; 299:R871-7. [DOI: 10.1152/ajpregu.00031.2010] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
High soy diets reduce injury in rat models of focal cerebral ischemia and are proposed as alternatives to hormone replacement therapy for postmenopausal women. The present study tests the hypothesis that the major soy isoflavone genistein and the daidzein metabolite equol are neuroprotective in transient focal cerebral ischemia in male and ovariectomized (OVX) female rats by inhibiting oxidative stress. Genistein is the primary circulating soy isoflavone in humans, whereas equol is the primary circulating isoflavone in rats. Male and OVX female Sprague-Dawley rats were fed an isoflavone-reduced diet alone or supplemented with genistein (500 ppm) or equol (250 ppm) for 2 wk prior to 90-min transient middle cerebral artery occlusion followed by reperfusion under isoflurane anesthesia. Indices of oxidative stress were determined 24 h after reperfusion, and cerebral injury was evaluated 3 days after reperfusion. Genistein and equol significantly reduced infarct size in both sexes. Further studies in OVX female rats revealed that this neuroprotection was accompanied by a decrease in NAD(P)H oxidase activity and superoxide levels in the brain. In addition, equol reduced plasma thiobarbituric acid reactive substances, and neurological deficits up to 7 days after injury. There were no significant differences in cerebral blood flow among treatment groups. In conclusion, dietary soy isoflavones are neuroprotective in transient focal cerebral ischemia in male and OVX female rats. These isoflavones may protect the brain via increases in endogenous antioxidant mechanisms and reduced oxidative stress.
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Affiliation(s)
| | - Jennifer C. Sullivan
- Pharmacology and Toxicology, and Vascular Biology Center, Medical College of Georgia, Augusta, Georgia,
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Weaver CM, Legette LL. Equol, via dietary sources or intestinal production, may ameliorate estrogen deficiency-induced bone loss. J Nutr 2010; 140:1377S-9S. [PMID: 20505019 PMCID: PMC2884336 DOI: 10.3945/jn.109.118331] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Equol, a product of intestinal metabolism of daidzein, is chemically similar to estrogen (without the lipophilic moiety) and has higher estrogen receptor-beta binding affinity than its parent precursor. In 2004, a long-term, randomized controlled trial that characterized postmenopausal women by their equol-producing status showed stronger advantages to lumbar spine bone mineral density (BMD) in equol- compared with nonequol-producers. Subsequent studies have related equol status of participants to change in bone turnover markers or BMD in response to soy isoflavone interventions. To our knowledge, we are the first to prescreen women for equol-producing status prior to initiating an intervention. In menopausal Western women, equol status did not affect the modest, but significant, reduction in bone resorption achieved with a soy isoflavone intervention.
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Swedenborg E, Power KA, Cai W, Pongratz I, Rüegg J. Regulation of estrogen receptor beta activity and implications in health and disease. Cell Mol Life Sci 2009; 66:3873-94. [PMID: 19669093 PMCID: PMC11115682 DOI: 10.1007/s00018-009-0118-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 07/21/2009] [Accepted: 07/22/2009] [Indexed: 02/06/2023]
Abstract
Together with the estrogen receptor (ER) alpha, estrogen receptor beta (ER beta ) mediates many of the physiological effects of estrogens. As ER beta is crucially involved in a variety of important physiological processes, its activity should be tightly regulated. ER beta regulation is achieved by hormone binding as well as by posttranslational modifications of the receptor. Furthermore, ER beta expression levels are under circadian control and can be regulated by DNA methylation of the ER beta promoter region. There are also a number of factors that can interfere with ER beta activity, such as phytoestrogens, endocrine disruptive chemicals, and growth factors. In this article, we outline different mechanisms of ER beta regulation and how they are implicated in various diseases. We also discuss how these insights might help to specifically target ER beta in drug design.
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Affiliation(s)
- Elin Swedenborg
- Department of Biosciences and Nutrition, Karolinska Institute, Hälsovägen 7, 141 57 Huddinge, Sweden
| | - Krista A. Power
- Guelph Food Research Centre, Agriculture and Agri-Food Canada, Guelph, ON Canada
| | - Wen Cai
- Department of Biosciences and Nutrition, Karolinska Institute, Hälsovägen 7, 141 57 Huddinge, Sweden
| | - Ingemar Pongratz
- Department of Biosciences and Nutrition, Karolinska Institute, Hälsovägen 7, 141 57 Huddinge, Sweden
| | - Joëlle Rüegg
- Department of Biosciences and Nutrition, Karolinska Institute, Hälsovägen 7, 141 57 Huddinge, Sweden
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Legette LL, Martin BR, Shahnazari M, Lee WH, Helferich WG, Qian J, Waters DJ, Arabshahi A, Barnes S, Welch J, Bostwick DG, Weaver CM. Supplemental dietary racemic equol has modest benefits to bone but has mild uterotropic activity in ovariectomized rats. J Nutr 2009; 139:1908-13. [PMID: 19710157 PMCID: PMC2744611 DOI: 10.3945/jn.109.108225] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Soy isoflavones and their metabolites, with estrogenic activity, have been considered candidates for reducing postmenopausal bone loss. In this study, we examined the effect of dietary equol, a bioactive metabolite of the soy isoflavone daidzein, on equol tissue distribution, bone parameters, and reproductive tissue activity using an adult ovariectomized (OVX) rat model. An 8-wk feeding study was conducted to compare 4 dietary treatments of equol (0, 50, 100, 200 mg/kg diet) in 6-mo-old OVX female Sprague-Dawley rats. A dose response increase in tissue equol concentrations was observed for serum, liver, kidney, and heart, and a plateau occurred at 100 mg equol/kg diet for intestine. In OVX rats receiving 200 mg equol/kg diet, femoral calcium concentration was greater than those receiving lower doses but was still less than SHAM (P < 0.05), and other bone measures were not improved. Tibia calcium concentrations were lower in OVX rats receiving 100 and 200 mg equol/kg diet compared with the OVX control rats. Trabecular bone mineral density of tibia was also lower in equol-fed OVX rats. At this dietary equol intake, uterine weight was higher (P < 0.05) than in other OVX groups but lower than the SHAM-operated intact rats. The 200 mg/kg diet dose of dietary equol significantly increased proliferative index in the uterine epithelium. Dietary equol had no stimulatory effect on mammary gland epithelium. We conclude that in OVX rats, a dietary equol dose that had modest effect on bone also exerts mild uterotropic effects.
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Affiliation(s)
- LeeCole L. Legette
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - Berdine R. Martin
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - Mohammad Shahnazari
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - Wang-Hee Lee
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - William G. Helferich
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - Junqi Qian
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - David J. Waters
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - Alireza Arabshahi
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - Stephen Barnes
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - Jo Welch
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - David G. Bostwick
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
| | - Connie M. Weaver
- Department of Foods and Nutrition and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907; Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801; Bostwick Laboratories, Richmond, VA 23060; Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907; and Department of Pharmacology-Toxicology, University of Alabama, Birmingham, AL 35294
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Estrogenic activity of bovine milk high or low in equol using immature mouse uterotrophic responses and an estrogen receptor transactivation assay. Cancer Epidemiol 2009; 33:61-8. [PMID: 19679050 DOI: 10.1016/j.canep.2009.04.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 02/24/2009] [Accepted: 04/02/2009] [Indexed: 01/26/2023]
Abstract
BACKGROUND Cow's milk contain phytoestrogens especially equol depending on the composition of the feed ration. However, it is unknown whether milk differing in equol exhibits different estrogenicity in model systems and thereby potentially in humans as milk consumers. METHODS The estrogenicity of high and low equol milk (HEM and LEM, respectively) and purified equol was investigated in immature female mice including mRNA expression of six estrogen-sensitive genes in uterine tissue. Extracts of HEM and LEM were also tested for estrogenicity in vitro in an estrogen receptor (ER) reporter gene assay with MVLN cells. RESULTS The total content of phytoestrogens was approximately 10 times higher in HEM compared with LEM, but levels of endogenous milk estrone and 17beta-estradiol were similar in the two milk types (503-566 and 60-64.6pg/ml, respectively). There was no difference in uterine weight between mice receiving LEM and HEM, and no difference from controls. Equol (50 times the concentration in HEM) was not uterotrophic. The ERbeta mRNA expression was down-regulated in the uteri of HEM mice compared with LEM and controls, but there was no difference between milk types for any of the other genes. Extracts of HEM showed a higher estrogenicity than extracts of LEM in MVLN cells, and there was a dose-dependent increase in estrogenicity by equol. CONCLUSION The higher in vitro estrogenicity of HEM was not reflected as a higher uterine weight in vivo although the down-regulation of ERbeta in uterine tissue of HEM mice could suggest some estrogenic activity of HEM at the gene expression level.
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Wood CE, Hester JM, Appt SE, Geisinger KR, Cline JM. Estrogen effects on epithelial proliferation and benign proliferative lesions in the postmenopausal primate mammary gland. J Transl Med 2008; 88:938-48. [PMID: 18607345 PMCID: PMC2691895 DOI: 10.1038/labinvest.2008.64] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Proliferative lesions of the mammary gland are risk markers and potential precursors for the development of breast cancer in postmenopausal women. In this study we evaluated mammary epithelial proliferation and proliferative lesions in a group of 63 aged postmenopausal macaques randomized by social group to receive one of three experimental diets for 8 months: (1) control; (2) control with 17beta-estradiol (E2) at the human equivalent dose of 1.0 mg per day; and (3) control with the soy phytoestrogen equol (EQ) at the human equivalent dose of 105 mg per day. In normal mammary epithelium, treatment with E2 but not EQ resulted in greater proliferation, epithelial area, and progesterone receptor expression (P<0.05 for all). Mammary lesions included columnar cell change (26/63), columnar cell hyperplasia with and without atypia (13/63), atypical ductal hyperplasia (6/63), and atypical lobular hyperplasia (3/63). Lesions were most common within terminal ductal lobular units. The prevalence of columnar cell hyperplasia (total and atypical cases) was higher in animals treated with E2 compared to control (P<0.05 for both). Compared to normal mammary epithelium, columnar cell lesions (CCLs) showed greater constitutive expression of estrogen receptor-alpha across all groups (P<0.001) and greater expression of progesterone receptor in response to E2 (P<0.01). Independent of treatment, animals with CCLs on histology had greater gene expression of estrogen receptor-alpha and markers of estrogen receptor activity (trefoil factor 1) and proliferation (gene for Ki67 antigen) at a site contralateral to the CCL (P<0.05 for all). These findings demonstrate that the terminal ductal lobular units of the postmenopausal mammary gland contain morphologically distinct cell populations that may hyperrespond to E2 exposure, resulting in specific types of hyperplastic lesions.
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Affiliation(s)
- Charles E Wood
- Department of Pathology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1040, USA.
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Messina MJ, Wood CE. Soy isoflavones, estrogen therapy, and breast cancer risk: analysis and commentary. Nutr J 2008; 7:17. [PMID: 18522734 PMCID: PMC2443803 DOI: 10.1186/1475-2891-7-17] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2008] [Accepted: 06/03/2008] [Indexed: 12/21/2022] Open
Abstract
There has been considerable investigation of the potential for soyfoods to reduce risk of cancer, and in particular cancer of the breast. Most interest in this relationship is because soyfoods are essentially a unique dietary source of isoflavones, compounds which bind to estrogen receptors and exhibit weak estrogen-like effects under certain experimental conditions. In recent years the relationship between soyfoods and breast cancer has become controversial because of concerns – based mostly on in vitro and rodent data – that isoflavones may stimulate the growth of existing estrogen-sensitive breast tumors. This controversy carries considerable public health significance because of the increasing popularity of soyfoods and the commercial availability of isoflavone supplements. In this analysis and commentary we attempt to outline current concerns regarding the estrogen-like effects of isoflavones in the breast focusing primarily on the clinical trial data and place these concerns in the context of recent evidence regarding estrogen therapy use in postmenopausal women. Overall, there is little clinical evidence to suggest that isoflavones will increase breast cancer risk in healthy women or worsen the prognosis of breast cancer patients. Although relatively limited research has been conducted, and the clinical trials often involved small numbers of subjects, there is no evidence that isoflavone intake increases breast tissue density in pre- or postmenopausal women or increases breast cell proliferation in postmenopausal women with or without a history of breast cancer. The epidemiologic data are generally consistent with the clinical data, showing no indication of increased risk. Furthermore, these clinical and epidemiologic data are consistent with what appears to be a low overall breast cancer risk associated with pharmacologic unopposed estrogen exposure in postmenopausal women. While more research is required to definitively allay concerns, the existing data should provide some degree of assurance that isoflavone exposure at levels consistent with historical Asian soyfood intake does not result in adverse stimulatory effects on breast tissue.
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Affiliation(s)
- Mark J Messina
- Nutrition Matters, Inc, 439 Calhoun Street, Port Townsend, WA 98368, USA.
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Rachoń D, Vortherms T, Seidlová-Wuttke D, Menche A, Wuttke W. Uterotropic effects of dietary equol administration in ovariectomized Sprague-Dawley rats. Climacteric 2008; 10:416-26. [PMID: 17852145 DOI: 10.1080/13697130701624757] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AIM The aim of the present study was to evaluate the uterotropic effects of the administration of dietary equol, a metabolite of soy-derived daidzein or formononetin present in red clover, in an ovariectomized rat model of menopause. METHOD Two doses of racemic equol were used (50 mg/kg of chow and 400 mg/kg of chow) and the results were compared with two doses of estradiol-3 benzoate (E2B) (4.3 mg/kg of chow and 17.3 mg/kg of chow). After 3 months, animals were sacrificed and the uteri were removed, weighed and paraffin-embedded for morphometrical and immunohistochemical evaluation. The expression of selected uterine estrogen-responsive genes was also measured using real-time reverse transcription-polymerase chain reaction. RESULTS Compared to controls, uterine weights in animals treated with high-dose equol were significantly higher, presented histologic features of mild estrogenic stimulation and had greater epithelial height and thickness of the uterine stroma and myometrium. Staining for the presence of the proliferating cell nuclear antigen (PCNA) also showed a greater prevalence of the PCNA-positive cells in the uterine stroma in animals treated with high-dose equol. Conversely, the percentage of PCNA-positive cells in the uterine epithelium was lower compared to the controls. Dietary high-dose equol treatment also increased significantly levels of uterine insulin-like growth factor 1, progesterone receptor and complement protein 3 mRNA. Although statistically significant, all these effects were, however, lower in magnitude compared to the effects of low- and high-dose E2B treatment. Low-dose equol did not have any effects on the above-studied parameters. CONCLUSION Long-term high-dose dietary equol administration to ovariectomized rats exerts uterotropic effects at the cellular and molecular level which question the safety of uncontrolled and unlimited consumption of soy or red clover supplements by postmenopausal women with intact uteri.
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Affiliation(s)
- D Rachoń
- Department of Clinical and Experimental Endocrinology, University of Göttingen, Göttingen, Germany
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Rachoń D, Seidlová-Wuttke D, Vortherms T, Wuttke W. Effects of dietary equol administration on ovariectomy induced bone loss in Sprague-Dawley rats. Maturitas 2007; 58:308-15. [PMID: 17961939 DOI: 10.1016/j.maturitas.2007.09.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 08/27/2007] [Accepted: 09/09/2007] [Indexed: 10/22/2022]
Abstract
UNLABELLED Oestrogen deficiency leads to a considerable bone loss, thus, osteopenia and osteoporosis are serious complications after menopause. OBJECTIVES To evaluate the effects of a daidzein metabolite equol on bone mass density (BMD) and markers of bone remodelling in an ovariectomized (ovx) rat model of postmenopausal bone loss and compare them with the effects of 17beta-estradiol. METHODS Twenty-eight female Sprague-Dawley rats were ovx and fed soy-free chow only (control group, n = 8), or with the addition of oestradiol-3 benzoate (E2B) (10mg/kg, n = 10) or equol (400 mg/kg, n = 10). At baseline and after 6-week treatment period, proximal tibia and lumbar spine BMD were measured using computer tomography. Animals were then sacrificed, blood was collected and uteri were removed. RESULTS Similarly to E2B, dietary equol decreased weight gain and showed mild uterotropic activity. E2B attenuated ovx induced BMD loss at proximal tibia whereas equol had no effect. At lumbar spine, however, equol not only attenuated trabecular bone loss but also increased its density. This effect was also apparent in animals treated with E2B. Cortical BMD at proximal tibia and lumbar spine were not very much influenced by ovx and treatment with E2B or equol did not induce significant changes at these sites. Plasma osteocalcin and type I collagen fragments (cross-laps) in equol treated animals did not differ from the controls whereas in E2B treated animals they were both significantly decreased. CONCLUSIONS In spite of its mild uterotropic potential, dietary equol shows limited bone sparing effects in ovx rats.
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Affiliation(s)
- Dominik Rachoń
- Department of Clinical and Experimental Endocrinology, University of Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany.
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Rachoń D, Vortherms T, Seidlová-Wuttke D, Wuttke W. Effects of dietary equol on body weight gain, intra-abdominal fat accumulation, plasma lipids, and glucose tolerance in ovariectomized Sprague-Dawley rats. Menopause 2007; 14:925-32. [PMID: 17414092 DOI: 10.1097/gme.0b013e31802d979b] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To evaluate the effects of dietary equol, a metabolite of the phytoestrogen daidzein, on body weight gain, intra-abdominal fat accumulation, plasma leptin, lipids, and glucose tolerance in ovariectomized rats and to compare them to the effects of 17beta-estradiol. DESIGN Twenty-eight female Sprague-Dawley rats were ovariectomized and fed soy-free chow with the addition of estradiol-3 benzoate (E2B) (10 mg/kg, n=10) or equol (400 mg/kg, n=10). The control group (n=8) received soy-free chow only. Weight and food intake were recorded once weekly. After 6 weeks, intra-abdominal fat was measured using computed tomography, and the intraperitoneal glucose tolerance test was performed. In the seventh week, the animals were killed, blood was collected for plasma, and uteri were removed. RESULTS Dietary equol significantly increased uterine mass. This effect was, however, 3.5 times lower in magnitude compared to E2B. Similar to E2B, dietary equol decreased weight gain, intra-abdominal fat accumulation, and plasma leptin levels. Equol-treated animals had also lower plasma total cholesterol and triglyceride levels compared to controls. E2B treatment also decreased plasma total cholesterol as well as high-density lipoprotein and low-density lipoprotein cholesterol. In the glucose tolerance test, the area under the curve was significantly smaller in the E2B- and equol-treated animals compared to controls. Also, E2B-treated animals had lower fasting plasma insulin levels. CONCLUSIONS In ovariectomized rats, dietary equol administration attenuates weight gain and shows favorable metabolic effects. However, because of its mild uterotrophic activity, its use in the prevention of postmenopausal weight gain and related metabolic disorders in women with an intact uterus is questionable in terms of safety and warrants further studies.
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Affiliation(s)
- Dominik Rachoń
- Department of Clinical and Experimental Endocrinology, University of Göttingen, Göttingen, Germany.
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Abstract
OBJECTIVE To evaluate the effect of Pueraria mirifica on vaginal symptoms, vaginal health index, vaginal pH, and vaginal cytology in healthy postmenopausal women. DESIGN A randomized, double-blind, placebo-controlled study. Healthy postmenopausal women, age 45 to 60 years old, were enrolled voluntarily and randomly received 20, 30, or 50 mg of Pueraria mirifica in capsules or placebo in identical capsules once daily for 24 weeks. RESULTS After 24 weeks of treatment, 71 women were evaluated. Fifty-one of 71 randomly received one of the three doses of Pueraria mirifica, and the remaining 20 received placebo. The mean vaginal dryness symptom in the Pueraria mirifica group decreased after 12 weeks of treatment. Pueraria mirifica increased vaginal maturation index (parabasal:intermediate:superficial cells) from 46:43:11 to 11:65:24 after 24 weeks of treatment. There was no significant difference of adverse effects between the Pueraria mirifica and placebo groups in this study. CONCLUSIONS Pueraria mirifica was proven to exhibit estrogenicity on vaginal tissue, to alleviate vaginal dryness symptoms and dyspareunia, to improve signs of vaginal atrophy, and to restore the atrophic vaginal epithelium in healthy postmenopausal women.
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Affiliation(s)
- Jittima Manonai
- Department of Obstetrics and Gynaecology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
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Yuan JP, Wang JH, Liu X. Metabolism of dietary soy isoflavones to equol by human intestinal microflora--implications for health. Mol Nutr Food Res 2007; 51:765-81. [PMID: 17579894 DOI: 10.1002/mnfr.200600262] [Citation(s) in RCA: 212] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Soy isoflavones have received considerable attention. Individuals with isoflavones-rich diets have significantly lower occurrences of cardiovascular disease, osteoporosis, and some cancers. The clinical effectiveness of soy isoflavones may be a function of the ability to biotransform soy isoflavones to the more potent estrogenic metabolite, equol, which may enhance the actions of soy isoflavones, owing to its greater affinity for estrogen receptors, unique antiandrogenic properties, and superior antioxidant activity. However, not all individuals consuming daidzein produce equol. Only approximately one-third to one-half of the population is able to metabolize daidzein to equol. This high variability in equol production is presumably attributable to interindividual differences in the composition of the intestinal microflora, which may play an important role in the mechanisms of action of isoflavones. But, the specific bacterial species in the colon involved in the production of equol are yet to be discovered. Therefore, future researches are aimed at identifying the specific bacterial species and strains that are capable of converting daidzein to equol or increasing equol production.
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Affiliation(s)
- Jian-Ping Yuan
- Food Engineering Research Center of State Education Ministry, College of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
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41
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Júnior UL, Cordellini S. Differential vascular adaptive response to stress exposure in male and female rats: role of gonadal hormones and endothelial cells. Stress 2007; 10:27-36. [PMID: 17454964 DOI: 10.1080/10253890601135426] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
UNLABELLED Although there are reports concerning a vascular adaptive response to stress in males, this is not yet defined in females. The aim of this study was to delineate functional gender differences in the rat vascular adaptive response to stress and to determine the ability of sex hormones to modulate the stress-induced vascular adaptive response. Responses to noradrenaline were evaluated in aortas, with and without endothelium, from intact, gonadectomized and gonadectomized-hormone-replaced males and females submitted or not to stress (2-h immobilization). Reactivity of the aorta of stressed and non-stressed intact males and females (n = 6-14 per group) was also examined in the presence of L-NAME or indomethacin. Stress decreased and gonadectomy increased maximal responses to noradrenaline in aortas with intact endothelium from both genders. Stress also reduced noradrenaline potency in males. In females, but not males, stress decreased the gonadectomy-induced noradrenaline hyper-reactivity to near that of intact non-stressed rats. Hormone replacement restored the gonadectomy-induced impaired vascular adaptive response to stress. L-NAME, but not indomethacin, abolished the stress-induced decrease in aorta reactivity of males and females. None of the procedures altered reactivity of aortas denuded of endothelium. CONCLUSION Stress-induced vascular adaptive responses show gender differences. The magnitude of the adaptive response is dependent on testicular hormones and involves endothelial nitric oxide-system hyperactivity.
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Affiliation(s)
- Ubirajara Lanza Júnior
- Department of Pharmacology, Institute of Biosciences, University Estadual Paulista, 18618-000, Rubião Júnior s/n, Botucatu, São Paulo. Brasil
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Wood CE, Appt SE, Clarkson TB, Franke AA, Lees CJ, Doerge DR, Cline JM. Effects of high-dose soy isoflavones and equol on reproductive tissues in female cynomolgus monkeys. Biol Reprod 2006; 75:477-86. [PMID: 16723506 DOI: 10.1095/biolreprod.106.052142] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Soy isoflavonoids have well-established estrogenic properties in cell culture and rodent models, raising concerns that high isoflavonoid intake may promote development of uterine and breast cancers. To address this concern we evaluated the effects of high-dose isoflavonoid supplements on reproductive tissues in a postmenopausal primate model. Thirty adult female ovariectomized monkeys (Macaca fascicularis) were randomized to receive a control diet 1) alone, 2) with 509 mg/day of the soy isoflavones genistein and daidzein (IF), or 3) with 1020 mg/day of racemic equol (EQ), an isoflavan, for approximately 1 mo. Doses are expressed in aglycone units as calorically scaled human equivalents. Total serum isoflavonoid levels 4 h postfeeding were <20 nmol/L, 2570.7 nmol/L, and 6944.8 nmol/L for control, IF, and EQ groups, respectively. Equol was the predominant serum isoflavonoid in both IF (72.5%) and EQ (99.7%) groups. Aglycones represented 0.9% (IF) and 0.5% (EQ) of total serum isoflavonoids. Histologically, uteri and mammary glands were diffusely atrophic in all groups. Uterine weight, endometrial thickness, glandular area, and epithelial proliferation in the uterus were not significantly different among treatment groups (ANOVA P > 0.1 for all). Endometrial progesterone receptor gene expression was significantly increased in the IF group (P = 0.02), while protein expression was not altered (ANOVA P > 0.1). Within the mammary gland, proliferation and indicators of estrogen exposure did not differ among treatment groups (ANOVA P > 0.1 for all). These findings indicate that high doses of dietary soy isoflavonoids have minimal uterotrophic or mammotrophic effects in an established primate model.
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Affiliation(s)
- Charles E Wood
- Department of Pathology/Section on Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1040, USA.
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Reinwald S, Weaver CM. Soy isoflavones and bone health: a double-edged sword? JOURNAL OF NATURAL PRODUCTS 2006; 69:450-9. [PMID: 16562857 DOI: 10.1021/np058104g] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Numerous publications and research studies on isoflavones have prompted a nationwide increase in the consumption of soy-based foods and supplements in the United States. Isoflavones are natural endocrine active compounds generally considered to promote health and prevent or slow the onset of certain chronic diseases such as osteoporosis. The beneficial effects of soy isoflavones on bone may, however, be life-stage specific and dependent on the estrogen receptor number and endogenous hormone milieu. Perimenopausal and early menopausal women may therefore be more receptive to the therapeutic effects of isoflavones on bone loss prior to the diminution of estrogen receptors that occurs in the postmenopausal years, whereas laboratory studies in developmental age range animals have demonstrated the potential for adverse effects following exposure to high levels of soy isoflavones. Clinical studies in developing humans that either support or refute findings in animal studies are lacking. The effects of chronic consumption of high levels of soy isoflavones at each life stage to assess risk-benefit ratios should be a high priority of research.
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Affiliation(s)
- Susan Reinwald
- Department of Food Science, Purdue University, West Lafayette, Indiana 47907-2009, USA
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Cooke PS, Selvaraj V, Yellayi S. Genistein, estrogen receptors, and the acquired immune response. J Nutr 2006; 136:704-8. [PMID: 16484547 DOI: 10.1093/jn/136.3.704] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Estrogen regulates thymic development and immune function. Despite the critical role of estrogens in inducing thymic involution and modulating immune responses, the mechanism of this effect is unclear. Similarly, humans and animals are exposed to increasing amounts of the estrogenic soy isoflavone genistein in the diet, but whether genistein can induce immune changes has not been definitively established. We reported previously that genistein induces thymic atrophy in mice, and decreases both humoral and cell-mediated immunity. These thymic effects of genistein occur via estrogen receptor (ER)-mediated and non-ER-mediated pathways. Genistein injections produced the most pronounced effects, but dietary administration to mice that produced serum genistein concentrations similar to those reported in human infants consuming soy formula also had demonstrable effects. Microarray analysis of the effects of estradiol and genistein on neonatal thymus indicated that estradiol affected genes involved in transcription, apoptosis, cell cycle, and thymic development and function; genistein had similar effects on many estradiol target genes, but also had unique actions not replicated by estradiol. Despite extensive work showing inhibitory effects of genistein on immunity, other rodent studies reported that genistein or other phytoestrogens stimulate various aspects of immune function. Although the present data strongly indicate that genistein can regulate immune function, possibly at physiologic concentrations, further work is required to definitively establish overall thymic and immune effects of genistein and soy, which may vary with age, species, and specific end point.
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Affiliation(s)
- Paul S Cooke
- Department of Veterinary Biosciences, University of Illinois, Urbana, 61802, USA.
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45
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Ju YH, Fultz J, Allred KF, Doerge DR, Helferich WG. Effects of dietary daidzein and its metabolite, equol, at physiological concentrations on the growth of estrogen-dependent human breast cancer (MCF-7) tumors implanted in ovariectomized athymic mice. Carcinogenesis 2006; 27:856-63. [PMID: 16399773 DOI: 10.1093/carcin/bgi320] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Genistein and daidzein are the main isoflavones in legumes. Equol is an intestinal bacterial metabolite of daidzein. In this study, we evaluated the estrogenic potential of daidzein and synthetic (+/-)-equol to stimulate growth of estrogen-dependent breast cancer (MCF-7) in vitro and in vivo. We hypothesize that estrogenic effects of daidzein and (+/-)-equol could modulate the growth of MCF-7 cells both in vitro and also once implanted into ovariectomized athymic mice. At concentrations between 0.001 and 50 microM, daidzein and (+/-)-equol stimulated the growth of MCF-7 cells with maximal stimulation at 1 muM in vitro. To evaluate their effects on the growth of MCF-7 cells implanted in ovariectomized athymic mice, two dietary dose-response studies [daidzein (125, 250, 500 and 1000 p.p.m.) and (+/-)-equol (250, 500 and 1000 p.p.m.)] were conducted. Tumor size and body weight were monitored weekly during the study. At completion of the study, we analyzed cellular proliferation of tumors using immunohistochemical staining (ki-67), pS2 expression in tumors using a real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and total daidzein and (+/-)-equol levels in plasma using liquid chromatography-electrospray tandem mass spectrometry (LC-ES/MS/MS). Dietary daidzein had a slight but significant stimulatory effect on MCF-7 tumor growth in mice. No significant induction of pS2 mRNA (an estrogen-responsive marker) in tumors by dietary daidzein was observed. Total plasma daidzein concentrations in plasma were between 0.25 and 1.52 microM. Dietary equol treatment (for 37 weeks) did not stimulate MCF-7 tumor growth. There were no statistical differences in tumor size, proliferation and pS2 expression among any treatment groups. Total equol concentrations in plasma were 2.10-3.21 microM. In conclusion, daidzein and (+/-)-equol have proliferative effects on MCF-7 cell growth in vitro within the concentration range tested. Dietary daidzein had a slight but significant stimulatory effect on tumor growth, whereas (+/-)-equol did not stimulate the growth of estrogen-dependent breast tumor growth in athymic mice, increase the cell proliferation in tumors, or induce an estrogen-responsive pS2 expression. Total daidzein or (+/-)-equol plasma levels in mice fed the isoflavones were in the range that stimulated MCF-7 cell growth in vitro. These results suggest that pharmacokinetic and/or metabolic factors attenuate the estrogenic effects of daidzein and equol in vivo.
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Affiliation(s)
- Young H Ju
- Department of Food Science and Human Nutrition, University of Illinois, 905 S Goodwin, Room 580 Bevier Hall, Urbana, IL 61801, USA
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46
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Totta P, Acconcia F, Virgili F, Cassidy A, Weinberg PD, Rimbach G, Marino M. Daidzein-sulfate metabolites affect transcriptional and antiproliferative activities of estrogen receptor-beta in cultured human cancer cells. J Nutr 2005; 135:2687-93. [PMID: 16251631 DOI: 10.1093/jn/135.11.2687] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Daidzein (D), a soy isoflavone, is almost completely metabolized in the gut and liver. This biotransformation converts D to more water-soluble products and may affect its biological activity. The ability of daidzein metabolites to modulate 17beta-estradiol (E2)-sensitive gene transcription, cell growth, and a proapoptotic cascade was determined in human cancer cells devoid of any estrogen receptor (ER) and rendered E2 sensitive after transfection with ERbeta. The data show that D and some but not all of its metabolites 1) induce promoter activity, 2) reduce proliferation, 3) promote p38/mitogen-activated protein kinase (MAPK) phosphorylation, and 4) activate a proapoptotic cascade involving the cleavage of caspase-3 and its substrate poly(ADP-ribose)polymerase (PARP) in human cancer cells in an ERbeta-dependent manner. Pretreatment of cells with ICI 182,780, a pure antiestrogen, completely prevented the actions of D and its metabolites. These findings highlight the important and complex influence of metabolic transformation on key physiological effects of isoflavones and demonstrate the need to take biotransformation into account when assessing the potential health benefits of consuming soy isoflavones.
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Affiliation(s)
- Pierangela Totta
- Department of Biology, University "Roma Tre," I-00146 Rome, Italy
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Gerber B, Scholz C, Reimer T, Briese V, Janni W. Complementary and alternative therapeutic approaches in patients with early breast cancer: a systematic review. Breast Cancer Res Treat 2005; 95:199-209. [PMID: 16254687 DOI: 10.1007/s10549-005-9005-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Complementary and alternative medicine (CAM) is becoming increasingly popular, particularly among patients with breast cancer. We have done a systematic review of studies published between 1995 and February 2005, identified through a comprehensive search. CAM encompasses a wide range of treatment modalities, including dietary and vitamin supplements, mind-body approaches, acupuncture, and herbal medicines. The objectives of CAM treatments are diverse: reduction of therapy-associated toxicity, improvement of cancer-related symptoms, fostering of the immune system and even direct anticancer effects. Clinical trials have generated few or no data on the efficacy of CAM, whether regarding disease recurrence, survival, overall quality of life or safety. Some CAM methods may even have adverse effects or reduce the efficacy of conventional treatment. The primary justification for CAM is based on empirical evidence, case studies, and hypothetical physiological effects. We conclude that available data on CAM modalities in the treatment of early-stage breast cancer does not support their application.
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Affiliation(s)
- B Gerber
- Department of Obstetrics and Gynecology, University of Rostock, Rostock, Germany.
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Atkinson C, Frankenfeld CL, Lampe JW. Gut bacterial metabolism of the soy isoflavone daidzein: exploring the relevance to human health. Exp Biol Med (Maywood) 2005; 230:155-70. [PMID: 15734719 DOI: 10.1177/153537020523000302] [Citation(s) in RCA: 358] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The indigenous intestinal microflora are involved in a variety of processes within the human body, and are important for maintaining host health. As such, interindividual differences in the ability to harbor certain intestinal bacteria might be associated with interindividual differences in health and/or disease susceptibility. In the last decade there has been considerable interest in phytoestrogen intakes in relation to human health. Daidzein, an isoflavone phytoestrogen found in soy, is metabolized to equol and O-desmethylangolensin (O-DMA) by intestinal bacteria. The specific bacterium/bacteria responsible for equol and O-DMA production in humans have yet to be identified definitively, but in vitro and animal studies have suggested that equol and O-DMA are more biologically active than their precursor daidzein. Interestingly, substantial interindividual differences in daidzein metabolism exist; following soy or daidzein consumption, approximately 30%-50% of the human population produce equol, and approximately 80%-90% produce O-DMA. Observational and intervention studies in humans have suggested that the ability to produce equol and O-DMA may be associated with reduced risk of certain diseases including breast and prostate cancers. However, relatively few studies have been conducted to date. In this review, we discuss the available evidence for a relationship between daidzeinmetabolizing phenotypes and human health, and suggest potential mechanisms for some of the reported relationships.
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Affiliation(s)
- Charlotte Atkinson
- Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, M4-B402, P.O. Box 19024, Seattle, WA 98109-1024, USA
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