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Quiroz-Delfi GO, Rider CV, Ferguson SS, Jarmusch AK, Mueller GA. Non-targeted chemical analysis of consumer botanical products labeled as blue cohosh (Caulophyllum thalictroides), goldenseal (Hydrastis canadensis), or yohimbe bark (Pausinystalia yohimbe) by NMR and MS. Anal Bioanal Chem 2024; 416:175-189. [PMID: 37910202 DOI: 10.1007/s00216-023-05004-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/22/2023] [Accepted: 10/05/2023] [Indexed: 11/03/2023]
Abstract
Consumers have unprecedented access to botanical dietary supplements through online retailers, making it difficult to ensure product quality and authenticity. Therefore, methods to survey and compare chemical compositions across botanical products are needed. Nuclear magnetic resonance (NMR) spectroscopy and non-targeted mass spectrometry (MS) were used to chemically analyze commercial products labeled as containing one of three botanicals: blue cohosh, goldenseal, and yohimbe bark. Aqueous and organic phase extracts were prepared and analyzed in tandem with NMR followed by MS. We processed the non-targeted data using multivariate statistics to analyze the compositional similarity across extracts. In each case, there were several product outliers that were identified using principal component analysis (PCA). Evaluation of select known constituents proved useful to contextualize PCA subgroups, which in some cases supported or refuted product authenticity. The NMR and MS data reached similar conclusions independently but were also complementary.
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Affiliation(s)
- Giovanni O Quiroz-Delfi
- Genome Integrity and Structural Biology, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, 27709, USA
- Immunity, Inflammation, and Disease Laboratory, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, 27709, USA
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, 27709, USA
| | - Cynthia V Rider
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, 27709, USA
| | - Stephen S Ferguson
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, 27709, USA
| | - Alan K Jarmusch
- Immunity, Inflammation, and Disease Laboratory, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, 27709, USA
| | - Geoffrey A Mueller
- Genome Integrity and Structural Biology, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, 27709, USA.
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2
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Taylor KW, Howdeshell KL, Bommarito PA, Sibrizzi CA, Blain RB, Magnuson K, Lemeris C, Tracy W, Baird DD, Jackson CL, Gaston SA, Rider CV, Walker VR, Rooney AA. Systematic evidence mapping informs a class-based approach to assessing personal care products and pubertal timing. Environ Int 2023; 181:108307. [PMID: 37948866 DOI: 10.1016/j.envint.2023.108307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 10/24/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023]
Abstract
BACKGROUND Personal care products (PCPs) contain many different compounds and are a source of exposure to endocrine disrupting chemicals (EDCs), including phthalates and phenols. Early-life exposure to EDCs commonly found in PCPs has been linked to earlier onset of puberty. OBJECTIVE To characterize the human and animal evidence on the association between puberty-related outcomes and exposure to PCPs and their chemical constituents and, if there is sufficient evidence, identify groups of chemicals and outcomes to support a systematic review for a class-based hazard or risk assessment. METHODS We followed the OHAT systematic review framework to characterize the human and animal evidence on the association between puberty-related health outcomes and exposure to PCPs and their chemical constituents. RESULTS Ninety-eight human and 299 animal studies that evaluated a total of 96 different chemicals were identified and mapped by key concepts including chemical class, data stream, and puberty-related health outcome. Among these studies, phthalates and phenols were the most well-studied chemical classes. Most of the phthalate and phenol studies examined secondary sex characteristics and changes in estradiol and testosterone levels. Studies evaluating PCP use and other chemical classes (e.g., parabens) had less data. CONCLUSIONS This systematic evidence map identified and mapped the published research evaluating the association between exposure to PCPs and their chemical constituents and puberty-related health outcomes. The resulting interactive visualization allows researchers to make evidence-based decisions on the available research by enabling them to search, sort, and filter the literature base of puberty-related studies by key concepts. This map can be used by researchers and regulators to prioritize and target future research and funding to reduce uncertainties and address data gaps. It also provides information to inform a class-based hazard or risk assessment on the association between phthalate and phenol exposures and puberty-related health outcomes.
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Affiliation(s)
- Kyla W Taylor
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
| | - Kembra L Howdeshell
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Paige A Bommarito
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | | | | | | | | | | | - Donna D Baird
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Chandra L Jackson
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA; National Institute on Minority Health and Health Disparities, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - Symielle A Gaston
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Cynthia V Rider
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Vickie R Walker
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Andrew A Rooney
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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3
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Johnson VJ, Rider CV, Luster MI, Brix A, Burleson GR, Cora M, Elmore SA, Frawley RP, Lopez FR, Mutlu E, Shockley KR, Pierfelice J, Burback B, Co CA, Germolec DR. Immunotoxicity of N-butylbenzenesulfonamide: impacts on immune function in adult mice and developmentally exposed rats. Toxicol Sci 2023; 196:71-84. [PMID: 37584675 PMCID: PMC10613960 DOI: 10.1093/toxsci/kfad083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023] Open
Abstract
N-butylbenzenesulfonamide (NBBS) is a high-production volume plasticizer that is an emerging contaminant of concern for environmental and human health. To understand the risks and health effects of exposure to NBBS, studies were conducted in adult-exposed mice and developmentally exposed rats to evaluate the potential for NBBS to modulate the immune system. Beginning between 8 and 9 weeks of age, dosed feed containing NBBS at concentrations of 0, 313, 625, 1250, 2500, and 5000 ppm was continuously provided to B6C3F1/N female mice for 28 days. Dosed feed was also continuously provided to time-mated Harlan Sprague Dawley (Sprague Dawley SD) rats at concentrations of 0-, 250-, 500-, and 1000-ppm NBBS from gestation day 6 to postnatal day 28 and in F1 rats until 11-14 weeks of age. Functional assessments of innate, humoral, and cell-mediated immunity were conducted in adult female mice and F1 rats following exposure to NBBS. In female mice, NBBS treatment suppressed the antibody-forming cell (AFC) response to SRBC with small increases in T-cell responses and natural killer (NK)-cell activity. In developmentally exposed rats, NBBS treatment-related immune effects were sex dependent. A positive trend in NK-cell activity occurred in male F1 rats while a negative trend occurred in female F1 rats. The AFC response to SRBC was decreased in female F1 rats but not in male F1 rats. These data provide evidence that oral exposure to NBBS has the potential to produce immunomodulatory effects on both innate and adaptive immune responses, and these effects appear to have some dependence on species, sex, and period of exposure (developmental vs adult).
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Affiliation(s)
- Victor J Johnson
- Burleson Research Technologies, Inc, Morrisville, North Carolina 27560, United States
| | - Cynthia V Rider
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina 27709, United States
| | - Michael I Luster
- Burleson Research Technologies, Inc, Morrisville, North Carolina 27560, United States
| | - Amy Brix
- Experimental Pathology Laboratories, Inc, Research Triangle Park, North Carolina 27709, United States
| | - Gary R Burleson
- Burleson Research Technologies, Inc, Morrisville, North Carolina 27560, United States
| | - Michelle Cora
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina 27709, United States
| | - Susan A Elmore
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina 27709, United States
| | - Rachel P Frawley
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina 27709, United States
| | - Franklin R Lopez
- Charles River Laboratories, Durham, North Carolina 27703, United States
| | - Esra Mutlu
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina 27709, United States
| | - Keith R Shockley
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina 27709, United States
- Division of Intramural Research, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina 27709, United States
| | | | | | - Caroll A Co
- Social and Scientific Systems Inc., a DLH Holdings Corp Company, Durham, North Carolina 27703, United States
| | - Dori R Germolec
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina 27709, United States
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4
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Patel D, Sorkin BC, Mitchell CA, Embry MR, Rina-Kong S, Adams RE, DeTemple ER, Reddam A, Gafner S, Kelber O, Rider CV, Oketch-Rabah H, Roe AL, Marles RJ, Dever J, Dentali S. Improving the rigor and utility of botanical toxicity studies: Recommended resources. Regul Toxicol Pharmacol 2023; 144:105471. [PMID: 37604297 PMCID: PMC10591999 DOI: 10.1016/j.yrtph.2023.105471] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/04/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023]
Abstract
Interest in botanicals, particularly as dietary supplement ingredients, is growing steadily. This growth, and the marketing of new ingredients and combination products as botanical dietary supplements, underscores the public health need for a better understanding of potential toxicities associated with use of these products. This article and accompanying template outline the resources to collect literature and relevant information to support the design of botanical toxicity studies. These resources provide critical information related to botanical identification, characterization, pre-clinical and clinical data, including adverse effects and interactions with pharmaceuticals. Toxicologists using these resources should collaborate with pharmacognosists and/or analytical chemists to enhance knowledge of the botanical material being tested. Overall, this guide and resource list is meant to help locate relevant information that can be leveraged to inform on decisions related to toxicity testing of botanicals, including the design of higher quality toxicological studies.
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Affiliation(s)
- Deval Patel
- Amway Corporation, Buena Park, California, USA
| | - Barbara C Sorkin
- Office of Dietary Supplements, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD, USA
| | | | - Michelle R Embry
- Health and Environmental Sciences Institute, Washington, DC, USA
| | | | | | | | - Aalekhya Reddam
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
| | | | - Olaf Kelber
- Bayer Consumer Health, Steigerwald Arzneimittelwerk GmbH, Darmstadt, Germany
| | - Cynthia V Rider
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Amy L Roe
- Procter & Gamble Company, 8700 Mason-Montgomery Rd, Box 2006, Cincinnati, OH, 45040, USA
| | - Robin J Marles
- USP Botanical Dietary Supplements and Herbal Medicines Expert Committee, United States Pharmacopeial Convention (USP), Rockville, MD, USA
| | - Joseph Dever
- Amway Corporation, Buena Park, California, USA; NSF International, Ann Arbor, MI, USA
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5
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Rager JE, Rider CV. Wrangling Whole Mixtures Risk Assessment: Recent Advances in Determining Sufficient Similarity. Curr Opin Toxicol 2023; 35:100417. [PMID: 37790747 PMCID: PMC10545370 DOI: 10.1016/j.cotox.2023.100417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Human health risk assessments for complex mixtures can address real-world exposures and protect public health. While risk assessors typically prefer whole mixture approaches over component-based approaches, data from the precise exposure of interest are often unavailable and surrogate data from a sufficiently similar mixture(s) are required. This review describes recent advances in determining sufficient similarity of whole, complex mixtures spanning the comparison of chemical features, bioactivity profiles, and statistical evaluation to determine "thresholds of similarity". Case studies, including water disinfection byproducts, botanical ingredients, and wildfire emissions, are used to highlight tools and methods. Limitations to application of sufficient similarity in risk-based decision making are reviewed and recommendations presented for developing best practice guidelines.
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Affiliation(s)
- Julia E. Rager
- The Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill
- The Institute for Environmental Health Solutions, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill
| | - Cynthia V. Rider
- Division of Translational Toxicology, National Institute of Environmental Health Sciences
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6
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Eccles KM, Karmaus AL, Kleinstreuer NC, Parham F, Rider CV, Wambaugh JF, Messier KP. A geospatial modeling approach to quantifying the risk of exposure to environmental chemical mixtures via a common molecular target. Sci Total Environ 2023; 855:158905. [PMID: 36152849 PMCID: PMC9979101 DOI: 10.1016/j.scitotenv.2022.158905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/09/2022] [Accepted: 09/17/2022] [Indexed: 05/14/2023]
Abstract
In the real world, individuals are exposed to chemicals from sources that vary over space and time. However, traditional risk assessments based on in vivo animal studies typically use a chemical-by-chemical approach and apical disease endpoints. New approach methodologies (NAMs) in toxicology, such as in vitro high-throughput (HTS) assays generated in Tox21 and ToxCast, can more readily provide mechanistic chemical hazard information for chemicals with no existing data than in vivo methods. In this paper, we establish a workflow to assess the joint action of 41 modeled ambient chemical exposures in the air from the USA-wide National Air Toxics Assessment by integrating human exposures with hazard data from curated HTS (cHTS) assays to identify counties where exposure to the local chemical mixture may perturb a common biological target. We exemplify this proof-of-concept using CYP1A1 mRNA up-regulation. We first estimate internal exposure and then convert the inhaled concentration to a steady state plasma concentration using physiologically based toxicokinetic modeling parameterized with county-specific information on ages and body weights. We then use the estimated blood plasma concentration and the concentration-response curve from the in vitro cHTS assay to determine the chemical-specific effects of the mixture components. Three mixture modeling methods were used to estimate the joint effect from exposure to the chemical mixture on the activity levels, which were geospatially mapped. Finally, a Monte Carlo uncertainty analysis was performed to quantify the influence of each parameter on the combined effects. This workflow demonstrates how NAMs can be used to predict early-stage biological perturbations that can lead to adverse health outcomes that result from exposure to chemical mixtures. As a result, this work will advance mixture risk assessment and other early events in the effects of chemicals.
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Affiliation(s)
- Kristin M Eccles
- National Institute of Environmental Health Science, Division of the Translational Toxicology, Durham, USA
| | - Agnes L Karmaus
- Integrated Laboratory Systems, an Inotiv Company, Morrisville, NC, USA
| | - Nicole C Kleinstreuer
- National Institute of Environmental Health Science, Division of the Translational Toxicology, Durham, USA
| | - Fred Parham
- National Institute of Environmental Health Science, Division of the Translational Toxicology, Durham, USA
| | - Cynthia V Rider
- National Institute of Environmental Health Science, Division of the Translational Toxicology, Durham, USA
| | - John F Wambaugh
- United States Environmental Protection Agency, Center for Computational Toxicology and Exposure, Durham, USA
| | - Kyle P Messier
- National Institute of Environmental Health Science, Division of the Translational Toxicology, Durham, USA.
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7
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Mutlu E, Cristy T, Stiffler B, Waidyanatha S, Chartier R, Jetter J, Krantz T, Shen G, Champion W, Miller B, Richey J, Burback B, Rider CV. Do Storage Conditions Affect Collected Cookstove Emission Samples? Implications for Field Studies. ANAL LETT 2022; 56:1911-1931. [PMID: 37200484 PMCID: PMC10054858 DOI: 10.1080/00032719.2022.2150772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/18/2022] [Accepted: 11/18/2022] [Indexed: 05/20/2023]
Abstract
Cookstove emissions are a significant source of indoor air pollution in developing countries and rural communities world-wide. Considering that many research sites for evaluating cookstove emissions and interventions are remote and require potentially lengthy periods of particulate matter (PM) filter sample storage in sub-optimal conditions (e.g., lack of cold storage), an important question is whether samples collected in the field are stable over time. To investigate this, red oak was burned in a natural-draft stove, and fine PM (PM2.5) was collected on polytetrafluoroethylene filters. Filters were stored at either ambient temperature or more optimal conditions (-20°C or -80°C) for up to 3 months and extracted. The effects of storage temperature and length on stability were evaluated for measurements of extractable organic matter (EOM), PM2.5, and polycyclic aromatic compound (PAC) levels in the filter extracts. A parallel, controlled laboratory condition was also evaluated to further explore sources of variability. In general, PM2.5 and EOM in both simulated field and laboratory samples were similar regardless of the storage condition or duration. The extracts were also analyzed by gas chromatography to quantify 22 PACs and determine similarities and/or differences between the conditions. PAC levels were a more sensitive stability measure in differentiating between storage conditions. The findings suggest that measurements are relatively consistent across storage duration/temperatures for filter samples with relatively low EOM levels. This study aims to inform protocols and filter storage procedures for exposure and intervention research conducted in low- and middle-income countries where studies may be budget- and infrastructure-limited.
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Affiliation(s)
- Esra Mutlu
- Center for Computational Toxicology and Exposure, U.S. EPA, RTP, NC, USA
- Division of the Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | - Suramya Waidyanatha
- Division of the Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Jim Jetter
- Center for Environmental Measurement and Modelling, U.S. EPA, RTP, NC, USA
| | - Todd Krantz
- Center for Environmental Measurement and Modelling, U.S. EPA, RTP, NC, USA
| | - Guofeng Shen
- Center for Environmental Measurement and Modelling, U.S. EPA, RTP, NC, USA
| | - Wyatt Champion
- Oak Ridge Institute for Science and Education (ORISE) Postdoctoral Fellow at U.S. EPA, Office of Research and Development, Center for Environmental Measurement and Modelling, RTP, NC, USA
| | | | | | | | - Cynthia V. Rider
- Division of the Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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8
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Pearson A, Gafner S, Rider CV, Embry M, Ferguson SS, Mitchell CA. Plant vs. Kidney: Evaluating Nephrotoxicity of Botanicals with the Latest Toxicological Tools. Curr Opin Toxicol 2022; 32:100371. [PMID: 36311298 PMCID: PMC9601601 DOI: 10.1016/j.cotox.2022.100371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Botanicals can cause nephrotoxicity via numerous mechanisms, including disrupting renal blood flow, damaging compartments along the nephron, and obstructing urinary flow. While uncommon, there are various reports of botanical-induced nephrotoxicity in the literature, such as from aristolochia (Aristolochia spp.) and rhubarb (Rheum spp.). However, at present, it is a challenge to assess the toxic potential of botanicals because their chemical composition is variable due to factors such as growing conditions and extraction techniques. Therefore, selecting a single representative sample for an in vivo study is difficult. Given the increasing use of botanicals as dietary supplements and herbal medicine, new approach methodologies (NAMs) are needed to evaluate the potential for renal toxicity to ensure public safety. Such approaches include in vitro models that use layers of physiological complexity to emulate the in vivo microenvironment, enhance the functional viability and differentiation of cell cultures, and improve sensitivity to nephrotoxic insults. Furthermore, computational tools such as physiologically based pharmacokinetic (PBPK) modeling can add confidence to these tools by simulating absorption, distribution, metabolism, and excretion. The development and implementation of NAMs for renal toxicity testing will allow specific mechanistic data to be generated, leading to a better understanding of the nephrotoxic potential of botanicals.
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Affiliation(s)
- Adam Pearson
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Cynthia V. Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Michelle Embry
- Health and Environmental Sciences Institute, Washington, DC, USA
| | - Stephen S Ferguson
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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9
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Rider CV, Birnbaum LS, DeVito MJ, Hertzberg RC, Rice GE, Teuschler LK. In Memoriam: Jane Ellen Simmons. Environ Health Perspect 2022; 130:101601. [PMID: 36300649 PMCID: PMC9608555 DOI: 10.1289/ehp12225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Affiliation(s)
- Cynthia V Rider
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Linda S Birnbaum
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Michael J DeVito
- Center for Computational Toxicology and Exposure, Office of Research and Development (ORD), U.S. Environmental Protection Agency (EPA), Research Triangle Park, North Carolina, USA
| | | | - Glenn E Rice
- Center for Public Health and Environmental Assessment, ORD, U.S. EPA, Cincinnati, Ohio, USA
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10
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Rider CV. Mixture Math: Deciding What to Add in a Cumulative Risk Assessment. Curr Opin Toxicol 2022; 31:100358. [PMID: 35813121 PMCID: PMC9262140 DOI: 10.1016/j.cotox.2022.100358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Component-based approaches for cumulative risk assessment provide an important tool for informing public health policy. While current quantitative cumulative risk assessments focus narrowly on pesticides that share a mechanism of action, growing scientific evidence supports expansion of their application to encompass stressors that target a common disease. Case studies have demonstrated dose additive effects of chemicals with different mechanisms of action on liver steatosis, craniofacial malformations, and male reproductive tract developmental disruption. Evidence also suggests that nonchemical stressors such as noise or psychosocial stress can modify effects of chemicals. Focused research attention is required before nonchemical stressors can routinely be included in quantitative cumulative risk assessments.
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Affiliation(s)
- Cynthia V. Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
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11
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Roell K, Koval LE, Boyles R, Patlewicz G, Ring C, Rider CV, Ward-Caviness C, Reif DM, Jaspers I, Fry RC, Rager JE. Development of the InTelligence And Machine LEarning (TAME) Toolkit for Introductory Data Science, Chemical-Biological Analyses, Predictive Modeling, and Database Mining for Environmental Health Research. Front Toxicol 2022; 4:893924. [PMID: 35812168 PMCID: PMC9257219 DOI: 10.3389/ftox.2022.893924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/30/2022] [Indexed: 01/09/2023] Open
Abstract
Research in environmental health is becoming increasingly reliant upon data science and computational methods that can more efficiently extract information from complex datasets. Data science and computational methods can be leveraged to better identify relationships between exposures to stressors in the environment and human disease outcomes, representing critical information needed to protect and improve global public health. Still, there remains a critical gap surrounding the training of researchers on these in silico methods. We aimed to address this gap by developing the inTelligence And Machine lEarning (TAME) Toolkit, promoting trainee-driven data generation, management, and analysis methods to “TAME” data in environmental health studies. Training modules were developed to provide applications-driven examples of data organization and analysis methods that can be used to address environmental health questions. Target audiences for these modules include students, post-baccalaureate and post-doctorate trainees, and professionals that are interested in expanding their skillset to include recent advances in data analysis methods relevant to environmental health, toxicology, exposure science, epidemiology, and bioinformatics/cheminformatics. Modules were developed by study coauthors using annotated script and were organized into three chapters within a GitHub Bookdown site. The first chapter of modules focuses on introductory data science, which includes the following topics: setting up R/RStudio and coding in the R environment; data organization basics; finding and visualizing data trends; high-dimensional data visualizations; and Findability, Accessibility, Interoperability, and Reusability (FAIR) data management practices. The second chapter of modules incorporates chemical-biological analyses and predictive modeling, spanning the following methods: dose-response modeling; machine learning and predictive modeling; mixtures analyses; -omics analyses; toxicokinetic modeling; and read-across toxicity predictions. The last chapter of modules was organized to provide examples on environmental health database mining and integration, including chemical exposure, health outcome, and environmental justice indicators. Training modules and associated data are publicly available online (https://uncsrp.github.io/Data-Analysis-Training-Modules/). Together, this resource provides unique opportunities to obtain introductory-level training on current data analysis methods applicable to 21st century science and environmental health.
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Affiliation(s)
- Kyle Roell
- The Institute for Environmental Health Solutions, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lauren E. Koval
- The Institute for Environmental Health Solutions, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Rebecca Boyles
- Research Computing, RTI International, Durham, NC, United States
| | - Grace Patlewicz
- Center for Computational Toxicology and Exposure, US Environmental Protection Agency, Durham, NC, United States
| | - Caroline Ring
- Center for Computational Toxicology and Exposure, US Environmental Protection Agency, Durham, NC, United States
| | - Cynthia V. Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Cavin Ward-Caviness
- Center for Public Health and Environmental Assessment, US Environmental Protection Agency, Chapel Hill, NC, United States
| | - David M. Reif
- Bioinformatics Research Center, Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States
| | - Ilona Jaspers
- The Institute for Environmental Health Solutions, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Curriculum in Toxicology and Environmental Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
- Center for Environmental Medicine, Asthma and Lung Biology, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
- Department of Pediatrics, Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Rebecca C. Fry
- The Institute for Environmental Health Solutions, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Curriculum in Toxicology and Environmental Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Julia E. Rager
- The Institute for Environmental Health Solutions, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Curriculum in Toxicology and Environmental Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
- Center for Environmental Medicine, Asthma and Lung Biology, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
- *Correspondence: Julia E. Rager,
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12
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Waidyanatha S, Black SR, Witt KL, Fennell TR, Swartz C, Recio L, Watson SL, Patel P, Fernando RA, Rider CV. The common indoor air pollutant α-pinene is metabolized to a genotoxic metabolite α-pinene oxide. Xenobiotica 2022; 52:301-311. [PMID: 35473450 DOI: 10.1080/00498254.2022.2070047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
1. α-Pinene caused a concentration-responsive increase in bladder hyperplasia and decrease in sperm counts in rodents following inhalation exposure. Additionally, it formed a prospective reactive metabolite, α-pinene oxide.2. To provide human relevant context for data generated in animal models and explore potential mechanism, we undertook studies to investigate the metabolism of α-pinene to α-pinene oxide and mutagenicity of α-pinene and α-pinene oxide.3. α-Pinene oxide was formed in rat and human microsomes and hepatocytes with some species differences. Based on area under the concentration versus time curves, the formation of α-pinene oxide was up to 4-fold higher in rats than in humans.4. While rat microsomes cleared α-pinene oxide faster than human microsomes, the clearance of α-pinene oxide in hepatocytes was similar between species.5. α-Pinene was not mutagenic with or without induced rat liver S9 in Salmonella typhimurium or Escherichia coli when tested up to 10,000 μg/plate while α-pinene oxide was mutagenic at ≥25 μg/plate.6. α-Pinene was metabolized to α-pinene oxide under the conditions of the bacterial mutation assay although the concentration was approximately 3-fold lower than the lowest α-pinene oxide concentration that was positive in the assay, potentially explaining the lack of mutagenicity observed with α-pinene.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Kristine L Witt
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Carol Swartz
- Integrated Laboratory Systems, Research Triangle Park, NC, USA
| | - Leslie Recio
- Integrated Laboratory Systems, Research Triangle Park, NC, USA
| | | | - Purvi Patel
- RTI International, Research Triangle Park, NC, USA
| | | | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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13
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Tice RR, Bassan A, Amberg A, Anger LT, Beal MA, Bellion P, Benigni R, Birmingham J, Brigo A, Bringezu F, Ceriani L, Crooks I, Cross K, Elespuru R, Faulkner DM, Fortin MC, Fowler P, Frericks M, Gerets HHJ, Jahnke GD, Jones DR, Kruhlak NL, Lo Piparo E, Lopez-Belmonte J, Luniwal A, Luu A, Madia F, Manganelli S, Manickam B, Mestres J, Mihalchik-Burhans AL, Neilson L, Pandiri A, Pavan M, Rider CV, Rooney JP, Trejo-Martin A, Watanabe-Sailor KH, White AT, Woolley D, Myatt GJ. In Silico Approaches In Carcinogenicity Hazard Assessment: Current Status and Future Needs. Comput Toxicol 2021; 20. [PMID: 35368437 DOI: 10.1016/j.comtox.2021.100191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Historically, identifying carcinogens has relied primarily on tumor studies in rodents, which require enormous resources in both money and time. In silico models have been developed for predicting rodent carcinogens but have not yet found general regulatory acceptance, in part due to the lack of a generally accepted protocol for performing such an assessment as well as limitations in predictive performance and scope. There remains a need for additional, improved in silico carcinogenicity models, especially ones that are more human-relevant, for use in research and regulatory decision-making. As part of an international effort to develop in silico toxicological protocols, a consortium of toxicologists, computational scientists, and regulatory scientists across several industries and governmental agencies evaluated the extent to which in silico models exist for each of the recently defined 10 key characteristics (KCs) of carcinogens. This position paper summarizes the current status of in silico tools for the assessment of each KC and identifies the data gaps that need to be addressed before a comprehensive in silico carcinogenicity protocol can be developed for regulatory use.
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Affiliation(s)
- Raymond R Tice
- RTice Consulting, Hillsborough, North Carolina, 27278, USA
| | | | - Alexander Amberg
- Sanofi Preclinical Safety, Industriepark Höchst, 65926 Frankfurt, Germany
| | - Lennart T Anger
- Genentech, Inc., South San Francisco, California, 94080, USA
| | - Marc A Beal
- Healthy Environments and Consumer Safety Branch, Health Canada, Government of Canada, Ottawa, Ontario, Canada K1A 0K9
| | | | | | - Jeffrey Birmingham
- GlaxoSmithKline, David Jack Centre for R&D, Ware, Hertfordshire, SG12 0DP, United Kingdom
| | - Alessandro Brigo
- Roche Pharmaceutical Research & Early Development, Pharmaceutical Sciences, Roche Innovation, Center Basel, F. Hoffmann-La Roche Ltd, CH-4070, Basel, Switzerland
| | | | - Lidia Ceriani
- Humane Society International, 1000 Brussels, Belgium
| | - Ian Crooks
- British American Tobacco (Investments) Ltd, GR&D Centre, Southampton, SO15 8TL, United Kingdom
| | | | - Rosalie Elespuru
- Food and Drug Administration, Center for Devices and Radiological Health, Silver Spring, Maryland, 20993, USA
| | - David M Faulkner
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Marie C Fortin
- Department of Pharmacology and Toxicology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey, 08855, USA
| | - Paul Fowler
- FSTox Consulting (Genetic Toxicology), Northamptonshire, United Kingdom
| | | | | | - Gloria D Jahnke
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, 27709, USA
| | | | - Naomi L Kruhlak
- Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, Maryland, 20993, USA
| | - Elena Lo Piparo
- Chemical Food Safety Group, Nestlé Research, CH-1000 Lausanne 26, Switzerland
| | - Juan Lopez-Belmonte
- Cuts Ice Ltd Chemical Food Safety Group, Nestlé Research, CH-1000 Lausanne 26, Switzerland
| | - Amarjit Luniwal
- North American Science Associates (NAMSA) Inc., Minneapolis, Minnesota, 55426, USA
| | - Alice Luu
- Healthy Environments and Consumer Safety Branch, Health Canada, Government of Canada, Ottawa, Ontario, Canada K1A 0K9
| | - Federica Madia
- European Commission, Joint Research Centre (JRC), Ispra, Italy
| | - Serena Manganelli
- Chemical Food Safety Group, Nestlé Research, CH-1000 Lausanne 26, Switzerland
| | | | - Jordi Mestres
- IMIM Institut Hospital Del Mar d'Investigacions Mèdiques and Universitat Pompeu Fabra, Doctor Aiguader 88, Parc de Recerca Biomèdica, 08003 Barcelona, Spain; and Chemotargets SL, Baldiri Reixac 4, Parc Científic de Barcelona, 08028, Barcelona, Spain
| | | | - Louise Neilson
- Broughton Nicotine Services, Oak Tree House, Earby, Lancashire, BB18 6JZ United Kingdom
| | - Arun Pandiri
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, 27709, USA
| | | | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, 27709, USA
| | - John P Rooney
- Integrated Laboratory Systems, LLC., Morrisville, North Carolina, 27560, USA
| | | | - Karen H Watanabe-Sailor
- School of Mathematical and Natural Sciences, Arizona State University, West Campus, Glendale, Arizona, 85306, USA
| | - Angela T White
- GlaxoSmithKline, David Jack Centre for R&D, Ware, Hertfordshire, SG12 0DP, United Kingdom
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Collins BJ, Kerns SP, Aillon K, Mueller G, Rider CV, DeRose EF, London RE, Harnly JM, Waidyanatha S. Correction to: Comparison of phytochemical composition of G. biloba extracts using a combination of non-targeted and targeted analytical approaches. Anal Bioanal Chem 2021; 413:6449-6450. [PMID: 34402966 DOI: 10.1007/s00216-021-03594-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Bradley J Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA.
| | | | | | - Geoffrey Mueller
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Eugene F DeRose
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Robert E London
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - James M Harnly
- U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, Methods and Applications Food Composition Lab, Beltsville, MD, 20705, USA
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
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15
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Waidyanatha S, Hackett M, Black SR, Stout MD, Fennell TR, Silinski MR, Watson SL, Licause J, Robinson VG, Sparrow B, Fernando RA, Cooper S, Rider CV. Toxicokinetic evaluation of the common indoor air pollutant, α-pinene, and its potential reactive metabolite, α-pinene oxide, following inhalation exposure in rodents. Toxicol Appl Pharmacol 2021; 418:115496. [PMID: 33744279 PMCID: PMC8336714 DOI: 10.1016/j.taap.2021.115496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 03/10/2021] [Accepted: 03/14/2021] [Indexed: 11/22/2022]
Abstract
The toxicokinetic behavior of α-pinene and its potential reactive metabolite, α-pinene oxide, was investigated following whole body inhalation exposure to 50 and 100 ppm α-pinene in rats and mice for 6 h per day for 7d. In both species and sexes, the maximum blood concentration (Cmax) increased more than proportionally while the increase in area under the concentration time curve (AUC) was proportional to the exposure concentration. When normalized to the calculated dose (D), both Cmax/D (male rats, 12.2-54.5; female rats, 17.4-74.1; male mice, 7.41-14.2; female mice, 6.59-13.0 (ng/mL)/(mg/kg)) and AUC/D (male rats, 28.9-31.1; female rats, 55.8-56.8; male mice, 18.1-19.4; female mice, 19.2-22.5 (h*ng/mL)/(mg/kg)) in rats were higher than in mice and in female rats were higher than in male rats; no sex difference was observed in mice. α-Pinene was eliminated from blood with half-lives between 12.2 and 17.4 h in rats and 6.18-19.4 h in mice. At the low dose, the ratio of α-pinene oxide to α-pinene, based on Cmax and AUC, respectively, was 0.200-0.237 and 0.279-0.615 in rats and 0.060-0.086 and 0.036-0.011 in mice demonstrating lower formation of the oxide in mice than in rats. At the high dose, the ratio decreased considerably in both species pointing to saturation of pathways leading to the formation of α-pinene oxide. α-Pinene and the oxide were quantified in the mammary glands of rats and mice with tissue to blood ratios of ≥23 demonstrating retention of these analytes in mammary glands. The findings of epoxide formation and species- and sex-differences in systemic exposure may be important in providing context and relating animal findings to human exposures.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | | | | | - Mathew D Stout
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | | | | | - Veronica G Robinson
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | | | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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16
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Rider CV, McHale CM, Webster TF, Lowe L, Goodson WH, La Merrill MA, Rice G, Zeise L, Zhang L, Smith MT. Using the Key Characteristics of Carcinogens to Develop Research on Chemical Mixtures and Cancer. Environ Health Perspect 2021; 129:35003. [PMID: 33784186 PMCID: PMC8009606 DOI: 10.1289/ehp8525] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 02/19/2021] [Accepted: 03/10/2021] [Indexed: 05/09/2023]
Abstract
BACKGROUND People are exposed to numerous chemicals throughout their lifetimes. Many of these chemicals display one or more of the key characteristics of carcinogens or interact with processes described in the hallmarks of cancer. Therefore, evaluating the effects of chemical mixtures on cancer development is an important pursuit. Challenges involved in designing research studies to evaluate the joint action of chemicals on cancer risk include the time taken to perform the experiments because of the long latency and choosing an appropriate experimental design. OBJECTIVES The objectives of this work are to present the case for developing a research program on mixtures of environmental chemicals and cancer risk and describe recommended approaches. METHODS A working group comprising the coauthors focused attention on the design of mixtures studies to inform cancer risk assessment as part of a larger effort to refine the key characteristics of carcinogens and explore their application. Working group members reviewed the key characteristics of carcinogens, hallmarks of cancer, and mixtures research for other disease end points. The group discussed options for developing tractable projects to evaluate the joint effects of environmental chemicals on cancer development. RESULTS AND DISCUSSION Three approaches for developing a research program to evaluate the effects of mixtures on cancer development were proposed: a chemical screening approach, a transgenic model-based approach, and a disease-centered approach. Advantages and disadvantages of each are discussed. https://doi.org/10.1289/EHP8525.
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Affiliation(s)
- Cynthia V. Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Cliona M. McHale
- Division of Environmental Health Sciences, University of California Berkeley, School of Public Health, Berkeley, California, USA
| | - Thomas F. Webster
- Department of Environmental Health, School of Public Health, Boston University, Boston, Massachusetts, USA
| | - Leroy Lowe
- Getting to Know Cancer (NGO), Truro, Nova Scotia, Canada
| | - William H. Goodson
- Department of Surgery, California Pacific Medical Center Research Institute, San Francisco, California, USA
| | - Michele A. La Merrill
- Department of Environmental Toxicology, University of California Davis, Davis, California, USA
| | - Glenn Rice
- Office of Research & Development, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio, USA
| | - Lauren Zeise
- Office of the Director, Office of Environmental Health and Hazard Assessment, California Environmental Protection Agency, Sacramento, California, USA
| | - Luoping Zhang
- Division of Environmental Health Sciences, University of California Berkeley, School of Public Health, Berkeley, California, USA
| | - Martyn T. Smith
- Division of Environmental Health Sciences, University of California Berkeley, School of Public Health, Berkeley, California, USA
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17
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Hsieh JH, Sedykh A, Mutlu E, Germolec DR, Auerbach SS, Rider CV. Harnessing In Silico, In Vitro, and In Vivo Data to Understand the Toxicity Landscape of Polycyclic Aromatic Compounds (PACs). Chem Res Toxicol 2020; 34:268-285. [PMID: 33063992 DOI: 10.1021/acs.chemrestox.0c00213] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Polycyclic aromatic compounds (PACs) are compounds with a minimum of two six-atom aromatic fused rings. PACs arise from incomplete combustion or thermal decomposition of organic matter and are ubiquitous in the environment. Within PACs, carcinogenicity is generally regarded to be the most important public health concern. However, toxicity in other systems (reproductive and developmental toxicity, immunotoxicity) has also been reported. Despite the large number of PACs identified in the environment, research attention to understand exposure and health effects of PACs has focused on a relatively limited subset, namely polycyclic aromatic hydrocarbons (PAHs), the PACs with only carbon and hydrogen atoms. To triage the rest of the vast number of PACs for more resource-intensive testing, we developed a data-driven approach to contextualize hazard characterization of PACs, by leveraging the available data from various data streams (in silico toxicity, in vitro activity, structural fingerprints, and in vivo data availability). The PACs were clustered on the basis of their in silico toxicity profiles containing predictions from 8 different categories (carcinogenicity, cardiotoxicity, developmental toxicity, genotoxicity, hepatotoxicity, neurotoxicity, reproductive toxicity, and urinary toxicity). We found that PACs with the same parent structure (e.g., fluorene) could have diverse in silico toxicity profiles. In contrast, PACs with similar substituted groups (e.g., alkylated-PAHs) or heterocyclics (e.g., N-PACs) with varying ring sizes could have similar in silico toxicity profiles, suggesting that these groups are better candidates for toxicity read-across analysis. The clusters/regions associated with certain in silico toxicity, in vitro activity, and structural fingerprints were identified. We found that genotoxicity/carcinogenicity (in silico toxicity) and xenobiotic homeostasis and stress response (in vitro activity), respectively, dominate the toxicity/activity variation seen in the PACs. The "hot spots" with enriched toxicity/activity in conjunction with availability of in vivo carcinogenicity data revealed regions of either data-poor (hydroxylated-PAHs) or data-rich (unsubstituted, parent PAHs) PACs. These regions offer potential targets for prioritization of further in vivo assessment and for chemical read-across efforts. The analysis results are searchable through an interactive web application (https://ntp.niehs.nih.gov/go/pacs_tableau), allowing for alternative hypothesis generation.
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Affiliation(s)
- Jui-Hua Hsieh
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709, United States
| | | | - Esra Mutlu
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709, United States
| | - Dori R Germolec
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709, United States
| | - Scott S Auerbach
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709, United States
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, North Carolina 27709, United States
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18
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Collins BJ, Kerns SP, Aillon K, Mueller G, Rider CV, DeRose EF, London RE, Harnly JM, Waidyanatha S. Comparison of phytochemical composition of Ginkgo biloba extracts using a combination of non-targeted and targeted analytical approaches. Anal Bioanal Chem 2020; 412:6789-6809. [PMID: 32865633 PMCID: PMC7496025 DOI: 10.1007/s00216-020-02839-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/26/2020] [Accepted: 07/23/2020] [Indexed: 01/23/2023]
Abstract
Ginkgo biloba extract (GbE) is a dietary supplement derived from an ethanolic extract of Ginkgo biloba leaves. Unfinished bulk GbE is used to make finished products that are sold as dietary supplements. The variable, complex composition of GbE makes it difficult to obtain consistent toxicological assessments of potential risk. The National Toxicology Program (NTP) observed hepatotoxicity in its rodent studies of a commercially available, unfinished GbE product, but the application of these results to the broader GbE supplement market is unclear. Here, we use a combination of non-targeted and targeted chromatographic and spectrophotometric methods to obtain profiles of 24 commercially available finished GbE products and unfinished standardized and unstandardized extracts with and without hydrolysis, then used principal component analysis to group unfinished products according to their similarity to each other and to National Institute of Standards and Technology (NIST) standard reference materials (SRM), and the finished products. Unfinished products were grouped into those that were characteristic and uncharacteristic of standardized GbE. Our work demonstrates that different analytical approaches produced similar classifications of characteristic and uncharacteristic products in unhydrolyzed samples, but the distinctions largely disappeared once the samples were hydrolyzed. Using our approach, the NTP GbE was most similar to two unfinished GbE products classified as characteristic, finished products, and the NIST GbE SRM. We propose that a simple analysis for the presence, absence, or amounts of compounds unique to GbE in unhydrolyzed samples could be sufficient to determine a sample’s authenticity. Graphical abstract![]()
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Affiliation(s)
- Bradley J Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA.
| | | | | | - Geoffrey Mueller
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Eugene F DeRose
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - Robert E London
- Division of Intramural Research, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
| | - James M Harnly
- U.S. Department of Agriculture, Beltsville Human Nutrition Research Center, Methods and Applications Food Composition Lab, Beltsville, MD, 20705, USA
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, 27709, USA
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20
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Waidyanatha S, Gibbs S, South N, Smith JP, Mutlu E, Burback B, Cao Y, Rider CV. Toxicokinetics of the plasticizer, N-butylbenzenesulfonamide, in plasma and brain following oral exposure in rodents: Route, species, and sex comparison. Toxicol Rep 2020; 7:711-722. [PMID: 32551233 PMCID: PMC7287195 DOI: 10.1016/j.toxrep.2020.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
N-Butylbenzenesulfonamide (NBBS) is a widely used plasticizer and hence there is potential for human exposure via oral routes. This work investigates the toxicokinetic behavior of NBBS in rodents following a single gavage (20, 60, and 200 mg/kg body weight) or multi-day feed administration (500, 1000, and 2000 ppm). In male and female rats following gavage administration, maximum plasma NBBS concentration, Cmax, was reached at ≤0.539 h. Cmax increased proportionally to the dose. Area under the curve (AUC) increased more than proportionally to the dose and was 4- to 5-fold higher in females than in males. In mice, plasma Cmax was reached at ≤0.136 h and increased proportionally to the dose in female mice and more than proportionally to the dose in males. AUC increased more than proportionally to the dose with no apparent sex difference. Elimination of NBBS in plasma was faster in mice (half-life (h); mice ≤0.432, rat ≤3.55). Oral bioavailability was higher in female rats (≥60%) than males (23-52%) with apparent saturation of clearance at ∼200 mg/kg body weight in females. In mice, bioavailability (5-14%) was lower with no apparent sex difference. NBBS was detected in brains of rats and mice but with low brain:plasma ratios (rats, ≤5; mice, ≤1) suggesting low potential to cross the blood brain barrier. Systemic exposure in male rats and mice following a single gavage administration was ≥48-fold higher than multi-day feed exposure. These data demonstrate potential species, sex, dose- and route-related difference in toxicokinetics of NBBS in rodents.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
| | - Seth Gibbs
- Battelle Memorial Institute, Columbus, OH, United States
| | - Natalie South
- Battelle Memorial Institute, Columbus, OH, United States
| | - Jeremy P Smith
- Battelle Memorial Institute, Columbus, OH, United States
| | - Esra Mutlu
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
| | - Brian Burback
- Battelle Memorial Institute, Columbus, OH, United States
| | - Yu Cao
- Battelle Memorial Institute, Columbus, OH, United States
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
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21
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Rider CV, Vallant M, Blystone C, Waidyanatha S, South NL, Xie G, Turner K. Short-term perinatal toxicity study in sprague Dawley rats with the plasticizer and emerging contaminant N-Butylbenzenesulfonamide. Toxicol Lett 2020; 330:159-166. [PMID: 32437845 PMCID: PMC9463652 DOI: 10.1016/j.toxlet.2020.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/27/2020] [Accepted: 05/05/2020] [Indexed: 10/24/2022]
Abstract
N-Butylbenzenesulfonamide (NBBS) is a plasticizer and emerging contaminant that has been detected in a wide array of environmental samples. There are very little toxicity data available with which to evaluate potential risk from exposure to NBBS or other structurally-related sulfonamide plasticizers. To address this knowledge gap, NBBS was selected by the National Toxicology Program for evaluation. The current short-term pre- and post-natal (perinatal) study aims to provide preliminary toxicity and gestational transfer data for NBBS. NBBS was administered via dosed feed at concentrations of 0, 625, 1250, 2500, 5000, and 10,000 ppm to time-mated Sprague Dawley (Hsd:Sprague Dawley SD®) rats from gestation day (GD) 6 through postnatal day (PND) 28. The high concentration of 10,000 ppm NBBS was overtly toxic to dams, and the group was removed on GD 17-18. Exposure to NBBS resulted in lower maternal weights during the gestational period in the 5000 and 10,000 ppm groups as compared to control weights. Dams also displayed lower weights in the lactational period, which resolved to control levels by PND 28. NBBS exposure did not affect pregnancy or littering parameters in F0 dams. However, pup survival was lower in the 5000 ppm group, and pup weights were dose-responsively lower than control pup weights with the difference expanding over the postnatal period. The lowest observed effect level (LOEL) based on significantly lower body weights was 5000 ppm NBBS for F0 dams and 2500 ppm NBBS for F1 pups. Preliminary data for NBBS levels indicated that the chemical was transferred from dams to offspring during the gestational period.
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Affiliation(s)
- Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | - Molly Vallant
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Chad Blystone
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Guanhua Xie
- Social & Scientific Systems Inc, Public Health Sciences, Durham, NC, USA
| | - Katie Turner
- RTI International, Discovery Sciences, Research Triangle Park, NC, USA, (current location Janssen R&D LLC, Spring House, PA, USA
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22
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Yamashita H, Surapureddi S, Kovi RC, Bhusari S, Ton TV, Li JL, Shockley KR, Peddada SD, Gerrish KE, Rider CV, Hoenerhoff MJ, Sills RC, Pandiri AR. Unique microRNA alterations in hepatocellular carcinomas arising either spontaneously or due to chronic exposure to Ginkgo biloba extract (GBE) in B6C3F1/N mice. Arch Toxicol 2020; 94:2523-2541. [PMID: 32306082 DOI: 10.1007/s00204-020-02749-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/08/2020] [Indexed: 12/18/2022]
Abstract
Ginkgo biloba extract (GBE) is used in traditional Chinese medicine as a herbal supplement for improving memory. Exposure of B6C3F1/N mice to GBE in a 2-year National Toxicology Program (NTP) bioassay resulted in a dose-dependent increase in hepatocellular carcinomas (HCC). To identify key microRNAs that modulate GBE-induced hepatocarcinogenesis, we compared the global miRNA expression profiles in GBE-exposed HCC (GBE-HCC) and spontaneous HCC (SPNT-HCC) with age-matched vehicle control normal livers (CNTL) from B6C3F1/N mice. The number of differentially altered miRNAs in GBE-HCC and SPNT-HCC was 74 (52 up and 22 down) and 33 (15 up and 18 down), respectively. Among the uniquely differentially altered miRNAs in GBE-HCC, miR-31 and one of its predicted targets, Cdk1 were selected for functional validation. A potential miRNA response element (MRE) in the 3'-untranslated regions (3'-UTR) of Cdk1 mRNA was revealed by in silico analysis and confirmed by luciferase assays. In mouse hepatoma cell line HEPA-1 cells, we demonstrated an inverse correlation between miR-31 and CDK1 protein levels, but no change in Cdk1 mRNA levels, suggesting a post-transcriptional effect. Additionally, a set of miRNAs (miRs-411, 300, 127, 134, 409-3p, and 433-3p) that were altered in the GBE-HCCs were also altered in non-tumor liver samples from the 90-day GBE-exposed group compared to the vehicle control group, suggesting that some of these miRNAs could serve as potential biomarkers for GBE exposure or hepatocellular carcinogenesis. These data increase our understanding of miRNA-mediated epigenetic regulation of GBE-mediated hepatocellular carcinogenesis in B6C3F1/N mice.
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MESH Headings
- 3' Untranslated Regions
- Animals
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- CDC2 Protein Kinase/genetics
- CDC2 Protein Kinase/metabolism
- Carcinoma, Hepatocellular/chemically induced
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/metabolism
- Cell Line, Tumor
- Cell Transformation, Neoplastic/chemically induced
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Epigenesis, Genetic
- Female
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic
- Ginkgo biloba
- Liver Neoplasms/chemically induced
- Liver Neoplasms/genetics
- Liver Neoplasms/metabolism
- Male
- Mice
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Plant Extracts/toxicity
- Time Factors
- Transcriptome
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Affiliation(s)
- Haruhiro Yamashita
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, Research Triangle Park, NC, 27709, USA
- Frontier Research Center, Taisho Pharmaceutical Co. Ltd, Tokyo, 100-6609, Japan
| | - Sailesh Surapureddi
- Signal Transduction Laboratory, DIR, NIEHS, Research Triangle Park, NC, 27709, USA
- United States Environmental Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC, 20460, USA
| | - Ramesh C Kovi
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, Research Triangle Park, NC, 27709, USA
- Experimental Pathology Laboratories Inc, Research Triangle Park, NC, 27709, USA
| | - Sachin Bhusari
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, Research Triangle Park, NC, 27709, USA
- Global Scientific and Regulatory Affairs, The Coca-Cola Company, 1 Coca Cola Plaza, NW, Atlanta, GA, USA
| | - Thai Vu Ton
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, Research Triangle Park, NC, 27709, USA
| | - Jian-Liang Li
- Integrative Bioinformatics Support Group, DIR, NIEHS, Research Triangle Park, NC, 27709, USA
| | - Keith R Shockley
- Biostatistics and Computational Biology Branch, DIR, NIEHS, Research Triangle Park, NC, 27709, USA
| | - Shyamal D Peddada
- Biostatistics and Computational Biology Branch, DIR, NIEHS, Research Triangle Park, NC, 27709, USA
- Department of Biostatistics, University of Pittsburgh, 7126 Public Health, 130 DeSoto Street, Pittsburgh, PA, 1526, USA
| | - Kevin E Gerrish
- Molecular Genomics Core Laboratory, DIR, NIEHS, Research Triangle Park, NC, 27709, USA
| | - Cynthia V Rider
- Toxicology Branch, DNTP, NIEHS, Research Triangle Park, NC, 27709, USA
| | - Mark J Hoenerhoff
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, Research Triangle Park, NC, 27709, USA
- In Vivo Animal Core, Unit for Laboratory Animal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Robert C Sills
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, Research Triangle Park, NC, 27709, USA
| | - Arun R Pandiri
- Cellular and Molecular Pathology Branch, DNTP, NIEHS, Research Triangle Park, NC, 27709, USA.
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23
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Waidyanatha S, Pierfelice J, Cristy T, Mutlu E, Burback B, Rider CV, Ryan K. A strategy for test article selection and phytochemical characterization of Echinacea purpurea extract for safety testing. Food Chem Toxicol 2020; 137:111125. [PMID: 31931071 PMCID: PMC7079738 DOI: 10.1016/j.fct.2020.111125] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/19/2019] [Accepted: 01/07/2020] [Indexed: 12/16/2022]
Abstract
Botanical dietary supplements (BDS) are used around the world for many purported therapeutic properties. The selection of an authentic product and it's phytochemical characterization is critical to generate robust safety data. Because botanicals are complex mixtures with variable quality, identification of a representative product for testing has been challenging. Echinacea is used for its purported immune stimulant properties and was listed as the 2nd top-selling BDS in 2018. However, there are limited safety data for Echinacea. Hence, the National Toxicology Program (NTP) has selected Echinacea for safety testing using rodent models. Here, we describe selection and comprehensive characterization of an Echinacea purpurea root extract to be used in the NTP testing program. Using non-targeted chemical analyses combined with chemometric analysis, a potential unfinished product (i.e., an extract that serves as source material for finished products) of Echinacea purpurea was selected. The product was then authenticated using chemical and DNA techniques and characterized, including the phytochemical composition. Among numerous constituents identified, caftaric acid, chicoric acid, chlorogenic acid and dodeca-2(E),4(E),8(Z),10(E/Z)-tetraenoic acid isobutylamide made up a small fraction of the extract. Based on these analyses, an approach is proposed for test article selection for Echinacea research which can be adapted to other botanicals.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | | | | | - Esra Mutlu
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Kristen Ryan
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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24
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Oketch-Rabah HA, Roe AL, Rider CV, Bonkovsky HL, Giancaspro GI, Navarro V, Paine MF, Betz JM, Marles RJ, Casper S, Gurley B, Jordan SA, He K, Kapoor MP, Rao TP, Sherker AH, Fontana RJ, Rossi S, Vuppalanchi R, Seeff LB, Stolz A, Ahmad J, Koh C, Serrano J, Low Dog T, Ko R. United States Pharmacopeia (USP) comprehensive review of the hepatotoxicity of green tea extracts. Toxicol Rep 2020; 7:386-402. [PMID: 32140423 PMCID: PMC7044683 DOI: 10.1016/j.toxrep.2020.02.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/04/2020] [Accepted: 02/12/2020] [Indexed: 02/07/2023] Open
Abstract
As part of the United States Pharmacopeia's ongoing review of dietary supplement safety data, a new comprehensive systematic review on green tea extracts (GTE) has been completed. GTEs may contain hepatotoxic solvent residues, pesticide residues, pyrrolizidine alkaloids and elemental impurities, but no evidence of their involvement in GTE-induced liver injury was found during this review. GTE catechin profiles vary significantly with manufacturing processes. Animal and human data indicate that repeated oral administration of bolus doses of GTE during fasting significantly increases bioavailability of catechins, specifically EGCG, possibly involving saturation of first-pass elimination mechanisms. Toxicological studies show a hepatocellular pattern of liver injury. Published adverse event case reports associate hepatotoxicity with EGCG intake amounts from 140 mg to ∼1000 mg/day and substantial inter-individual variability in susceptibility, possibly due to genetic factors. Based on these findings, USP included a cautionary labeling requirement in its Powdered Decaffeinated Green Tea Extract monograph that reads as follows: "Do not take on an empty stomach. Take with food. Do not use if you have a liver problem and discontinue use and consult a healthcare practitioner if you develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes)."
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Key Words
- ADME, Absorption, distribution, metabolism, and excretion
- ALP, alkaline phosphatase
- ALT, alanine aminotransferase
- AST, aspartate aminotransferase
- AUC, area under the curve
- Bw, body weight
- C, Catechin
- CAM, causality assessment method
- CG, (+)‐catechin‐3‐gallate
- CIH, Concanavalin A-induced hepatitis
- CMC, chemistry, manufacturing, and controls
- COMT, catechol‐O‐methyltransferase
- Camellia sinensis
- ConA, Concanavalin A
- DILI, drug‐induced liver injury
- DILIN, Drug‐Induced Liver Injury Network
- DO, Diversity Outbred
- DS, Dietary Supplement
- DSAE, JS3 USP Dietary Supplements Admission Evaluations Joint Standard-Setting Subcommittee
- Dietary supplements
- EC, (–)‐epicatechin
- ECG, (‐)‐epicatechin‐3‐gallate
- EFSA, European Food Safety Authority
- EGC, (–)‐epigallocatechin
- EGCG, (–)‐epigallocatechin‐3‐gallate
- FDA, United States Food and Drug Administration
- GC, (+)‐gallocatechin
- GCG, (–)‐gallocatechin‐3‐gallate
- GT(E), green tea or green tea extract
- GT, green tea
- GTE, green tea extract
- GTEH, EP Green Tea Extract Hepatotoxicity Expert Panel
- Green tea
- Green tea extract
- HDS, herbal dietary supplement
- HPMC, Hydroxypropyl methylcellulose
- Hepatotoxicity
- LD50, lethal dose, median
- LFT(s), liver function test(s)
- LT(s), Liver test(s)
- Liver injury
- MGTT, Minnesota Green Tea Trial
- MIDS, multi-ingredient dietary supplement
- MRL, maximum residue limit
- NAA, N-acetyl aspartate
- NIDDK, National Institute of Diabetes and Digestive and Kidney Diseases
- NIH, National Institutes of Health
- NOAEL, no observed adverse effect level
- NTP, National Toxicology Program
- OSM, online supplementary material
- PAs, Pyrrolizidine Alkaloids
- PD-1, Programmed death domain-1
- PDGTE, powdered decaffeinated green tea extract
- PK/PD, pharmacokinetics and pharmacodynamics
- RUCAM, Roussel Uclaf Causality Assessment Method
- SIDS, single-ingredient dietary supplement
- TGF-beta, Transforming growth factor beta
- USP, United States Pharmacopeia
- γ-GT, Gamma-glutamyl transferase
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Affiliation(s)
- Hellen A. Oketch-Rabah
- U.S. Pharmacopeial Convention, Rockville, MD, USA
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Amy L. Roe
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
- Vice Chair, (USP GTEH EP, 2015-2020 cycle)
| | - Cynthia V. Rider
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Herbert L. Bonkovsky
- U.S. FDA Liaison to the USP GTEH EP (2015-2020 cycle)
- Section on Gastroenterology & Hepatology, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, 27157, USA
| | - Gabriel I. Giancaspro
- U.S. Pharmacopeial Convention, Rockville, MD, USA
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Victor Navarro
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
| | - Mary F. Paine
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, WA, USA
| | - Joseph M. Betz
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Robin J. Marles
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Steven Casper
- U.S. FDA Liaison to the USP GTEH EP (2015-2020 cycle)
| | - Bill Gurley
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Scott A. Jordan
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Kan He
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Mahendra P. Kapoor
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Theertham P. Rao
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Averell H. Sherker
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
- Liver Diseases Research Branch National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 6707 Democracy Blvd., Bethesda, MD, USA
| | - Robert J. Fontana
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Simona Rossi
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
| | | | - Leonard B. Seeff
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
| | - Andrew Stolz
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
| | - Jawad Ahmad
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
| | - Christopher Koh
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
- Liver Diseases Branch, Intramural Research Program, National Institute of Diabetes and Digestive and Kidney Diseases, 10 Center Drive, Building 10, Rm 9B-16, Bethesda, MD, 20892,USA
| | - Jose Serrano
- Expert Members of the Drug Induced Liver Injury Network (DILIN), USA
- Liver Diseases Research Branch National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 6707 Democracy Blvd., Bethesda, MD, USA
| | - Tieraona Low Dog
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
| | - Richard Ko
- United States Pharmacopeia Green Tea Hepatotoxicity Expert Panel (USP GTEH EP, 2015-2020 cycle), Rockville, MD, USA
- Chair (USP GTEH EP, 2015-2020 cycle)
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25
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Waidyanatha S, Black SR, Patel PR, Rider CV, Watson SL, Snyder RW, Fennell TR. Disposition and metabolism of N-butylbenzenesulfonamide in Sprague Dawley rats and B6C3F1/N mice and in vitro in hepatocytes from rats, mice, and humans. Toxicol Lett 2020; 319:225-236. [PMID: 31760063 PMCID: PMC7028346 DOI: 10.1016/j.toxlet.2019.11.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 11/07/2019] [Accepted: 11/17/2019] [Indexed: 11/22/2022]
Abstract
N-Butylbenzenesulfonamide (NBBS) is a plasticizer detected in the environment suggesting potential human exposure. These studies investigated the in vitro hepatic clearance and disposition of [14C]NBBS in rodents following a single gavage (2, 20 or 200 mg/kg) or intravenous (IV) administration (20 mg/kg). NBBS was cleared slower in hepatocytes from humans compared to rodents. [14C]NBBS was well-absorbed in male rats following gavage administration and excreted extensively in urine (70-76 %) and feces (11-15 %) 72 h following administration. Following a 20 mg/kg gavage dose in male rats, 25 % of the dose was excreted in bile by 24 h suggesting that observed fecal excretion was due to biliary excretion. The radioactivity was distributed to tissues with 14 % and 8 % of the administered dose remaining in tissues at 24 and 72 h, respectively. There was no apparent dose-dependent effect in disposition in male rats. Disposition patterns were similar in female rats (urine, 83 %; feces, 14 %) and male (urine, 69 %; feces, 11 %) and female (urine, 72 %; feces, 9 %) mice following gavage administration of 20 mg/kg. The disposition following IV administration was similar to that of gavage. Urinary radiochemical profiles were similar between doses, routes, species, and sexes. Among numerous metabolites identified, oxidative metabolites of NBBS predominated.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | - Sherry R Black
- RTI International, Discovery Sciences, Research Triangle Park, NC, USA
| | - Purvi R Patel
- RTI International, Discovery Sciences, Research Triangle Park, NC, USA
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Scott L Watson
- RTI International, Discovery Sciences, Research Triangle Park, NC, USA
| | - Rodney W Snyder
- RTI International, Discovery Sciences, Research Triangle Park, NC, USA
| | - Timothy R Fennell
- RTI International, Discovery Sciences, Research Triangle Park, NC, USA
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26
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Ryan KR, Huang MC, Ferguson SS, Waidyanatha S, Ramaiahgari S, Rice JR, Dunlap PE, Auerbach SS, Mutlu E, Cristy T, Peirfelice J, DeVito MJ, Smith-Roe SL, Rider CV. Evaluating Sufficient Similarity of Botanical Dietary Supplements: Combining Chemical and In Vitro Biological Data. Toxicol Sci 2019; 172:316-329. [PMID: 31504990 PMCID: PMC6876258 DOI: 10.1093/toxsci/kfz189] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Botanical dietary supplements are complex mixtures with numerous potential sources of variation along the supply chain from raw plant material to the market. Approaches for determining sufficient similarity (ie, complex mixture read-across) may be required to extrapolate efficacy or safety data from a tested sample to other products containing the botanical ingredient(s) of interest. In this work, screening-level approaches for generating both chemical and biological-response profiles were used to evaluate the similarity of black cohosh (Actaea racemosa) and Echinacea purpurea samples to well-characterized National Toxicology Program (NTP) test articles. Data from nontargeted chemical analyses and gene expression of toxicologically important hepatic receptor pathways (aryl hydrocarbon receptor [AhR], constitutive androstane receptor [CAR], pregnane X receptor [PXR], farnesoid X receptor [FXR], and peroxisome proliferator-activated receptor alpha [PPARα]) in primary human hepatocyte cultures were used to determine similarity through hierarchical clustering. Although there were differences in chemical profiles across black cohosh samples, these differences were not reflected in the biological-response profiles. These findings highlight the complexity of biological-response dynamics that may not be reflected in chemical composition profiles. Thus, biological-response data could be used as the primary basis for determining similarity among black cohosh samples. Samples of E. purpurea displayed better correlation in similarity across chemical and biological-response measures. The general approaches described herein can be applied to complex mixtures with unidentified active constituents to determine when data from a tested mixture (eg, NTP test article) can be used for hazard identification of sufficiently similar mixtures, with the knowledge of toxicological targets informing assay selection when possible.
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Affiliation(s)
- Kristen R Ryan
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Madelyn C Huang
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Stephen S Ferguson
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Sreenivasa Ramaiahgari
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Julie R Rice
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Paul E Dunlap
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Scott S Auerbach
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Esra Mutlu
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | | | | | - Michael J DeVito
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Stephanie L Smith-Roe
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
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27
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Waidyanatha S, Mutlu E, Gibbs S, Stiffler B, Andre J, Burback B, Rider CV. Systemic exposure to Ginkgo biloba extract in male F344/NCrl rats: Relevance to humans. Food Chem Toxicol 2019; 131:110586. [PMID: 31202939 DOI: 10.1016/j.fct.2019.110586] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 12/12/2022]
Abstract
Ginkgo biloba extract (GBE) is a popular botanical dietary supplement used worldwide and the safety of use is a public health concern. While GBE is a complex mixture, the terpene trilactones and flavonol glycosides are believed to elicit the pharmacological and/or toxicological effects of GBE. In a National Toxicology Program (NTP) 2-year rodent bioassay with GBE, hepatotoxicity was observed in rodents (≥100 mg/kg in rats, ≥ 200 mg/kg in mice). Subsequently, questions arose about whether or not the GBE used in NTP studies was representative of other GBE products and how rodent doses are related to human doses. To address these, we generated systemic exposure data for terpene trilactones in male rats following oral administration of 30, 100, and 300 mg/kg GBE test article from the 2-year bioassay. Dose-normalized Cmax and AUC∞ for terpene trilactones from the current study were within 5-fold of published rodent studies using a standardized GBE preparation. Comparison of our rat systemic exposure data at 100 mg/kg GBE to published human data following ingestion of 240 mg GBE-containing product showed that the rat/human exposure multiple was 3-22, for terpene trilactones. These data demonstrate the relevance of NTP rodent toxicity data to humans.
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Affiliation(s)
- Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | - Esra Mutlu
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | | | | | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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Hubbard TD, Hsieh JH, Rider CV, Sipes NS, Sedykh A, Collins BJ, Auerbach SS, Xia M, Huang R, Walker NJ, DeVito MJ. Using Tox21 High-Throughput Screening Assays for the Evaluation of Botanical and Dietary Supplements. ACTA ACUST UNITED AC 2019; 5:10-25. [PMID: 30944845 PMCID: PMC6442399 DOI: 10.1089/aivt.2018.0020] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Introduction: Recent nationwide surveys found that natural products, including botanical dietary supplements, are used by ∼18% of adults. In many cases, there is a paucity of toxicological data available for these substances to allow for confident evaluations of product safety. The National Toxicology Program (NTP) has received numerous nominations from the public and federal agencies to study the toxicological effects of botanical dietary supplements. The NTP sought to evaluate the utility of in vitro quantitative high-throughput screening (qHTS) assays for toxicological assessment of botanical and dietary supplements. Materials and Methods: In brief, concentration–response assessments of 90 test substances, including 13 distinct botanical species, and individual purported active constituents were evaluated using a subset of the Tox21 qHTS testing panel. The screen included 20 different endpoints that covered a broad range of biologically relevant signaling pathways to detect test article effects upon endocrine activity, nuclear receptor signaling, stress response signaling, genotoxicity, and cell death signaling. Results and Discussion: Botanical dietary supplement extracts induced measurable and diverse activity. Elevated biological activity profiles were observed following treatments with individual chemical constituents relative to their associated botanical extract. The overall distribution of activity was comparable to activities exhibited by compounds present in the Tox21 10K chemical library. Conclusion: Botanical supplements did not exhibit minimal or idiosyncratic activities that would preclude the use of qHTS platforms as a feasible method to screen this class of compounds. However, there are still many considerations and further development required when attempting to use in vitro qHTS methods to characterize the safety profile of botanical/dietary supplements.
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Affiliation(s)
- Troy D Hubbard
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | | | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Nisha S Sipes
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | | | - Bradley J Collins
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Scott S Auerbach
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Menghang Xia
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland
| | - Ruili Huang
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland
| | - Nigel J Walker
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Michael J DeVito
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
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Rider CV, Walker N, Waidyanatha S. Getting to the Root of the Matter: Challenges and Recommendations for Assessing the Safety of Botanical Dietary Supplements. Clin Pharmacol Ther 2018; 104:429-431. [PMID: 29745419 PMCID: PMC6113061 DOI: 10.1002/cpt.1088] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/09/2018] [Accepted: 04/11/2018] [Indexed: 11/07/2022]
Abstract
The National Toxicology Program's (NTP) mission is "to evaluate agents of public health concern, by developing and applying the tools of modern toxicology and molecular biology." Botanical dietary supplements (BDS) represent agents of public health concern due to widespread exposure to high doses, a lack of safety data for most products, variable quality, and reports of adverse events. This commentary will address lessons learned in NTP testing activities with BDS and recommendations for moving forward.
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Affiliation(s)
- Cynthia V. Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Nigel Walker
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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Shipkowski KA, Betz JM, Birnbaum LS, Bucher JR, Coates PM, Hopp DC, MacKay D, Oketch-Rabah H, Walker NJ, Welch C, Rider CV. Naturally complex: Perspectives and challenges associated with Botanical Dietary Supplement Safety assessment. Food Chem Toxicol 2018; 118:963-971. [PMID: 29626579 PMCID: PMC6087675 DOI: 10.1016/j.fct.2018.04.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/02/2018] [Accepted: 04/03/2018] [Indexed: 10/17/2022]
Abstract
Due to the extensive use of botanical dietary supplements by consumers in the United States, there is a need for appropriate research and data to support safety assessments. Complexity and variability, both natural and introduced, of botanical dietary supplements make research on these products difficult. Botanical dietary supplements are regulated by the Food and Drug Administration (FDA) under the Federal Food, Drug, and Cosmetic Act (FD&C Act), as amended by the 1994 Dietary Supplement Health and Education Act (DSHEA). They are regulated as a category of food, which differs from the regulation of pharmaceutical products. Both manufacturers and the FDA are faced with the challenge of determining the best approaches for evaluating and monitoring the safety of botanical products. High quality botanicals research requires accurate identification and characterization of the material being studied. Inconsistent results in efficacy studies of botanical dietary supplements have led to efforts to improve the rigor and reproducibility of research in the field. Addressing the challenges associated with botanical dietary supplement safety is a global effort requiring coordination between numerous stakeholders, including researchers, suppliers, manufacturers, and regulators, all of whom play a role in ensuring that high quality products are available on the market.
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Affiliation(s)
- Kelly A Shipkowski
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA; ICF International, Inc., Durham, NC, USA
| | - Joseph M Betz
- Office of Dietary Supplements, National Institutes of Health, Bethesda, MD, USA
| | - Linda S Birnbaum
- National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - John R Bucher
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Paul M Coates
- Office of Dietary Supplements, National Institutes of Health, Bethesda, MD, USA
| | - D Craig Hopp
- National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | - Duffy MacKay
- Council for Responsible Nutrition, Washington, DC, USA
| | | | - Nigel J Walker
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Cara Welch
- US Food and Drug Administration, Silver Spring, MD, USA
| | - Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
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Taylor KW, Joubert BR, Braun JM, Dilworth C, Gennings C, Hauser R, Heindel JJ, Rider CV, Webster TF, Carlin DJ. Statistical Approaches for Assessing Health Effects of Environmental Chemical Mixtures in Epidemiology: Lessons from an Innovative Workshop. Environ Health Perspect 2016; 124:A227-A229. [PMID: 27905274 PMCID: PMC5132642 DOI: 10.1289/ehp547] [Citation(s) in RCA: 156] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Quantifying the impact of exposure to environmental chemical mixtures is important for identifying risk factors for diseases and developing more targeted public health interventions. The National Institute of Environmental Health Sciences (NIEHS) held a workshop in July 2015 to address the need to develop novel statistical approaches for multi-pollutant epidemiology studies. The primary objective of the workshop was to identify and compare different statistical approaches and methods for analyzing complex chemical mixtures data in both simulated and real-world data sets. At the workshop, participants compared approaches and results and speculated as to why they may have differed. Several themes emerged: a) no one statistical approach appeared to outperform the others, b) many methods included some form of variable reduction or summation of the data before statistical analysis, c) the statistical approach should be selected based upon a specific hypothesis or scientific question, and d) related mixtures data should be shared among researchers to more comprehensively and accurately address methodological questions and statistical approaches. Future efforts should continue to design and optimize statistical approaches to address questions about chemical mixtures in epidemiological studies.
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Affiliation(s)
- Kyla W. Taylor
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
- Address correspondence to K.W. Taylor, National Institute of Environmental Health Sciences, P.O. Box 12233, MD K2-04, Research Triangle Park, North Carolina 27709 USA. Telephone: (919) 316-4707. E-mail:
| | - Bonnie R. Joubert
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Joe M. Braun
- Department of Epidemiology, Brown University, Providence, Rhode Island, USA
| | - Caroline Dilworth
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Chris Gennings
- Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Russ Hauser
- Departments of Environmental Health and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Jerry J. Heindel
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Cynthia V. Rider
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Thomas F. Webster
- Department of Environmental Health, Boston University School of Public Health, Boston, Massachusetts, USA
| | - Danielle J. Carlin
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
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Rider CV, Chan P, Herbert RA, Kissling GE, Fomby LM, Hejtmancik MR, Witt KL, Waidyanatha S, Travlos GS, Kadiiska MB. Dermal Exposure to Cumene Hydroperoxide: Assessing Its Toxic Relevance and Oxidant Potential. Toxicol Pathol 2016; 44:749-62. [PMID: 26985019 DOI: 10.1177/0192623316636712] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cumene hydroperoxide (CHP) is a high production volume chemical that is used to generate phenol and acetone. Dermal exposure to CHP was hypothesized to result in systemic tissue toxicity, production of free radicals, and consequent decrease in plasma antioxidant levels. To evaluate the hypothesis and characterize the toxicity of CHP, male and female B6C3F1/N mice and F344/N rats were exposed to varying doses of CHP applied topically for 14 or 90 days. No significant changes in survival or body weight of mice and rats were observed following 14 days of exposure. However, 90 days of CHP exposure at the high dose (12 mg/kg) triggered a significant decrease (-15%) in the body weight of the male rat group only. Irritation of the skin was observed at the site of application and was characterized by inflammation and epidermal hyperplasia. In treated animals, histology of liver tissue, free radical generation, and antioxidant levels in blood plasma were not significantly changed as compared to the corresponding controls. Consistent with the lack of systemic damage, no increase in micronucleated erythrocytes was seen in peripheral blood. In conclusion, topical CHP application caused skin damage only at the application site and did not cause systemic tissue impairment.
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Affiliation(s)
- Cynthia V Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | - Po Chan
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | - Ron A Herbert
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | - Grace E Kissling
- Division of Intramural Research, Biostatistics & Computational Biology Branch, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | | | | | - Kristine L Witt
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | - Greg S Travlos
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Park, North Carolina, USA
| | - Maria B Kadiiska
- Division of Intramural Research, Inflammation, Immunity, and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
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Howdeshell KL, Rider CV, Wilson VS, Furr JR, Lambright CR, Gray LE. Dose Addition Models Based on Biologically Relevant Reductions in Fetal Testosterone Accurately Predict Postnatal Reproductive Tract Alterations by a Phthalate Mixture in Rats. Toxicol Sci 2015; 148:488-502. [PMID: 26350170 DOI: 10.1093/toxsci/kfv196] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Challenges in cumulative risk assessment of anti-androgenic phthalate mixtures include a lack of data on all the individual phthalates and difficulty determining the biological relevance of reduction in fetal testosterone (T) on postnatal development. The objectives of the current study were 2-fold: (1) to test whether a mixture model of dose addition based on the fetal T production data of individual phthalates would predict the effects of a 5 phthalate mixture on androgen-sensitive postnatal male reproductive tract development, and (2) to determine the biological relevance of the reductions in fetal T to induce abnormal postnatal reproductive tract development using data from the mixture study. We administered a dose range of the mixture (60, 40, 20, 10, and 5% of the top dose used in the previous fetal T production study consisting of 300 mg/kg per chemical of benzyl butyl (BBP), di(n)butyl (DBP), diethyl hexyl phthalate (DEHP), di-isobutyl phthalate (DiBP), and 100 mg dipentyl (DPP) phthalate/kg; the individual phthalates were present in equipotent doses based on their ability to reduce fetal T production) via gavage to Sprague Dawley rat dams on GD8-postnatal day 3. We compared observed mixture responses to predictions of dose addition based on the previously published potencies of the individual phthalates to reduce fetal T production relative to a reference chemical and published postnatal data for the reference chemical (called DAref). In addition, we predicted DA (called DAall) and response addition (RA) based on logistic regression analysis of all 5 individual phthalates when complete data were available. DA ref and DA all accurately predicted the observed mixture effect for 11 of 14 endpoints. Furthermore, reproductive tract malformations were seen in 17-100% of F1 males when fetal T production was reduced by about 25-72%, respectively.
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Affiliation(s)
- Kembra L Howdeshell
- *Division of the National Toxicology Program (NTP), National Institute of Environmental Health Sciences (NIEHS), PO Box 12233, Research Triangle Park (RTP), North Carolina 27709 and
| | - Cynthia V Rider
- *Division of the National Toxicology Program (NTP), National Institute of Environmental Health Sciences (NIEHS), PO Box 12233, Research Triangle Park (RTP), North Carolina 27709 and
| | - Vickie S Wilson
- Reproductive Toxicology Branch, Toxicology Assessment Division (TAD), National Health and Environmental Effects Research Laboratories, Office of Research and Development, US Environmental Protection Agency (US EPA), RTP, North Carolina 27711
| | - Johnathan R Furr
- Reproductive Toxicology Branch, Toxicology Assessment Division (TAD), National Health and Environmental Effects Research Laboratories, Office of Research and Development, US Environmental Protection Agency (US EPA), RTP, North Carolina 27711
| | - Christy R Lambright
- Reproductive Toxicology Branch, Toxicology Assessment Division (TAD), National Health and Environmental Effects Research Laboratories, Office of Research and Development, US Environmental Protection Agency (US EPA), RTP, North Carolina 27711
| | - L Earl Gray
- Reproductive Toxicology Branch, Toxicology Assessment Division (TAD), National Health and Environmental Effects Research Laboratories, Office of Research and Development, US Environmental Protection Agency (US EPA), RTP, North Carolina 27711
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Wolf CJ, Rider CV, Lau C, Abbott BD. Evaluating the additivity of perfluoroalkyl acids in binary combinations on peroxisome proliferator-activated receptor-α activation. Toxicology 2014; 316:43-54. [DOI: 10.1016/j.tox.2013.12.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/18/2013] [Accepted: 12/07/2013] [Indexed: 10/25/2022]
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Rider CV, Carlin DJ, DeVito MJ, Thompson CL, Walker NJ. Mixtures research at NIEHS: an evolving program. Toxicology 2013; 313:94-102. [PMID: 23146757 PMCID: PMC4232209 DOI: 10.1016/j.tox.2012.10.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 10/03/2012] [Accepted: 10/06/2012] [Indexed: 10/27/2022]
Abstract
The National Institute of Environmental Health Sciences (NIEHS) has a rich history in evaluating the toxicity of mixtures. The types of mixtures assessed by the Division of the National Toxicology Program (DNTP) and the extramural community (through the Division of Extramural Research and Training, DERT) have included a broad range of chemicals and toxicants, with each study having a unique set of questions and design considerations. Some examples of the types of mixtures studied include: groundwater contaminants, pesticides/fertilizers, dioxin-like chemicals (assessing the toxic equivalency approach), drug combinations, air pollution, metals, polycyclic aromatic hydrocarbons, technical mixtures (e.g., pentachlorophenol, flame retardants), and mixed entities (e.g., herbals, asbestos). These endeavors have provided excellent data on the toxicity of specific mixtures and have been informative to the human health risk assessment process in general (e.g., providing data on low dose exposures to environmental chemicals). However, the mixtures research effort at NIEHS, to date, has been driven by test article nominations to the DNTP or by investigator-initiated research through DERT. Recently, the NIEHS has embarked upon an effort to coordinate mixtures research across both intramural and extramural divisions in order to maximize mixtures research results. A path forward for NIEHS mixtures research will be based on feedback from a Request for Information (RFI) designed to gather up-to-date views on the knowledge gaps and roadblocks to evaluating mixtures and performing cumulative risk assessment, and a workshop organized to bring together mixtures experts from risk assessment, exposure science, biology, epidemiology, and statistics. The future of mixtures research at NIEHS will include projects from nominations to DNTP, studies by extramural investigators, and collaborations across government agencies that address high-priority questions in the field of mixtures research.
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Affiliation(s)
- Cynthia V Rider
- Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), 111 Alexander Drive, Research Triangle Park, North Carolina, USA
| | - Danielle J Carlin
- Division of Extramural Research and Training (DERT), National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), 111 Alexander Drive, Research Triangle Park, North Carolina, USA
| | - Micheal J DeVito
- Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), 111 Alexander Drive, Research Triangle Park, North Carolina, USA
| | - Claudia L Thompson
- Division of Extramural Research and Training (DERT), National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), 111 Alexander Drive, Research Triangle Park, North Carolina, USA
| | - Nigel J Walker
- Division of the National Toxicology Program (DNTP), National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), 111 Alexander Drive, Research Triangle Park, North Carolina, USA
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Rider CV, Boekelheide K, Catlin N, Gordon CJ, Morata T, Selgrade MK, Sexton K, Simmons JE. Cumulative risk: toxicity and interactions of physical and chemical stressors. Toxicol Sci 2013; 137:3-11. [PMID: 24154487 DOI: 10.1093/toxsci/kft228] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recent efforts to update cumulative risk assessment procedures to incorporate nonchemical stressors ranging from physical to psychosocial reflect increased interest in consideration of the totality of variables affecting human health and the growing desire to develop community-based risk assessment methods. A key roadblock is the uncertainty as to how nonchemical stressors behave in relationship to chemical stressors. Physical stressors offer a reasonable starting place for measuring the effects of nonchemical stressors and their modulation of chemical effects (and vice versa), as they clearly differ from chemical stressors; and "doses" of many physical stressors are more easily quantifiable than those of psychosocial stressors. There is a commonly held belief that virtually nothing is known about the impact of nonchemical stressors on chemically mediated toxicity or the joint impact of coexposure to chemical and nonchemical stressors. Although this is generally true, there are several instances where a substantial body of evidence exists. A workshop titled "Cumulative Risk: Toxicity and Interactions of Physical and Chemical Stressors" held at the 2013 Society of Toxicology Annual Meeting provided a forum for discussion of research addressing the toxicity of physical stressors and what is known about their interactions with chemical stressors, both in terms of exposure and effects. Physical stressors including sunlight, heat, radiation, infectious disease, and noise were discussed in reference to identifying pathways of interaction with chemical stressors, data gaps, and suggestions for future incorporation into cumulative risk assessments.
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Affiliation(s)
- Cynthia V Rider
- * Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
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Rider CV, Nyska A, Cora MC, Kissling GE, Smith C, Travlos GS, Hejtmancik MR, Fomby LM, Colleton CA, Ryan MJ, Kooistra L, Morrison JP, Chan PC. Toxicity and carcinogenicity studies of Ginkgo biloba extract in rat and mouse: liver, thyroid, and nose are targets. Toxicol Pathol 2013; 42:830-43. [PMID: 23960164 DOI: 10.1177/0192623313501235] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ginkgo biloba extract (GBE) is a popular herbal supplement that is used to improve circulation and brain function. In spite of widespread human exposure to relatively high doses over potentially long periods of time, there is a paucity of data from animal studies regarding the toxicity and carcinogenicity associated with GBE. In order to fill this knowledge gap, 3-month and 2-year toxicity and carcinogenicity studies with GBE administered by oral gavage to B6C3F1/N mice and F344/N rats were performed as part of the National Toxicology Program's Dietary Supplements and Herbal Medicines Initiative. The targets of GBE treatment were the liver, thyroid, and nose. These targets were consistent across exposure period, sex, and species, albeit with varying degrees of effect observed among studies. Key findings included a notably high incidence of hepatoblastomas in male and female mice and evidence of carcinogenic potential in the thyroid gland of both mice and rats. Various nonneoplastic lesions were observed beyond control levels in the liver, thyroid gland, and nose of rats and mice administered GBE. Although these results cannot be directly extrapolated to humans, the findings fill an important data gap in assessing risk associated with GBE use.
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Affiliation(s)
- Cynthia V Rider
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Abraham Nyska
- Integrated Laboratory Systems Incorporated, Research Triangle Park, Durham, North Carolina, USA
| | - Michelle C Cora
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Grace E Kissling
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Cynthia Smith
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Gregory S Travlos
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | | | | | | | | | - Linda Kooistra
- Charles River Laboratories, Pathology Associates, Durham, North Carolina, USA
| | - James P Morrison
- Charles River Laboratories, Pathology Associates, Durham, North Carolina, USA
| | - Po C Chan
- National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
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Carlin DJ, Rider CV, Woychik R, Birnbaum LS. Unraveling the health effects of environmental mixtures: an NIEHS priority. Environ Health Perspect 2013; 121:A6-8. [PMID: 23409283 PMCID: PMC3553446 DOI: 10.1289/ehp.1206182] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
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Rider CV, Dourson ML, Hertzberg RC, Mumtaz MM, Price PS, Simmons JE. Incorporating nonchemical stressors into cumulative risk assessments. Toxicol Sci 2012; 127:10-7. [PMID: 22345310 DOI: 10.1093/toxsci/kfs088] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The role of nonchemical stressors in modulating the human health risk associated with chemical exposures is an area of increasing attention. On 9 March 2011, a workshop titled "Approaches for Incorporating Nonchemical Stressors into Cumulative Risk Assessment" took place during the 50th Anniversary Annual Society of Toxicology Meeting in Washington D.C. Objectives of the workshop included describing the current state of the science from various perspectives (i.e., regulatory, exposure, modeling, and risk assessment) and presenting expert opinions on currently available methods for incorporating nonchemical stressors into cumulative risk assessments. Herein, distinct frameworks for characterizing exposure to, joint effects of, and risk associated with chemical and nonchemical stressors are discussed.
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Affiliation(s)
- Cynthia V Rider
- National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
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Rider CV, Furr JR, Wilson VS, Gray LE. Cumulative effects of in utero administration of mixtures of reproductive toxicants that disrupt common target tissues via diverse mechanisms of toxicity. ACTA ACUST UNITED AC 2010; 33:443-62. [PMID: 20487044 DOI: 10.1111/j.1365-2605.2009.01049.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although risk assessments are typically conducted on a chemical-by-chemical basis, the 1996 Food Quality Protection Act required the US Environmental Protection Agency to consider cumulative risk of chemicals that act via a common mechanism of toxicity. To this end, we are conducting studies with mixtures of chemicals to elucidate mechanisms of joint action at the systemic level with the goal of providing a framework for assessing the cumulative effects of reproductive toxicants. Previous mixture studies conducted with antiandrogenic chemicals are reviewed briefly and two new studies are described. In all binary mixture studies, rats were dosed during pregnancy with chemicals, singly or in pairs, at dosage levels equivalent to approximately one-half of the ED50 for hypospadias or epididymal agenesis. The binary mixtures included androgen receptor (AR) antagonists (vinclozolin plus procymidone), phthalate esters [di(n-butyl) phthalate (DBP) plus benzyl n-butyl phthalate (BBP) and diethyl hexyl phthalate (DEHP) plus DBP], a phthalate ester plus an AR antagonist (DBP plus procymidone), a mixed mechanism androgen signalling disruptor (linuron) plus BBP, and two chemicals which disrupt epididymal differentiation through entirely different toxicity pathways: DBP (AR pathway) plus 2,3,7,8 TCDD (AhR pathway). We also conducted multi-component mixture studies combining several 'antiandrogens'. In the first study, seven chemicals (four pesticides and three phthalates) that elicit antiandrogenic effects at two different sites in the androgen signalling pathway (i.e. AR antagonist or inhibition of androgen synthesis) were combined. In the second study, three additional phthalates were added to make a 10 chemical mixture. In both the binary mixture studies and the multi-component mixture studies, chemicals that targeted male reproductive tract development displayed cumulative effects that exceeded predictions based on a response-addition model and most often were in accordance with predictions based on dose-addition models. In summary, our results indicate that compounds that act by disparate mechanisms of toxicity to disrupt the dynamic interactions among the interconnected signalling pathways in differentiating tissues produce cumulative dose-additive effects, regardless of the mechanism or mode of action of the individual mixture component.
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Affiliation(s)
- C V Rider
- MD-72, Reproductive Toxicology Branch, T A Division, NHEERL, ORD, US Environmental Protection Agency, RTP, NC 27711, USA
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Rider CV, Hartig PC, Cardon MC, Lambright CR, Bobseine KL, Guillette LJ, Gray LE, Wilson VS. Differences in sensitivity but not selectivity of xenoestrogen binding to alligator versus human estrogen receptor alpha. Environ Toxicol Chem 2010; 29:2064-71. [PMID: 20821664 PMCID: PMC2944037 DOI: 10.1002/etc.233] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Reproductive abnormalities in alligators exposed to contaminants in Lake Apopka, Florida, USA represent a clear example of endocrine disruption in wildlife. Several of these contaminants that are not able to bind to mammalian estrogen receptors (such as atrazine and cyanazine) have previously been reported to bind to the alligator estrogen receptor from oviductal tissue. Binding of known Lake Apopka contaminants to full length estrogen receptors alpha from human (hERalpha) and alligator (aERalpha) was assessed in a side-by-side comparison within the same assay system. Baculovirus-expressed recombinant hERalpha and aERalpha were used in a competitive binding assay. Atrazine and cyanazine were not able to bind to either receptor. p,p'-Dicofol was able to bind to aERalpha with a concentration inhibiting 50% of binding (IC50) of 4 microM, while only partially displacing 17beta-estradiol (E2) from hERalpha and yielding a projected IC50 of 45 microM. Chemicals that only partially displaced E2 from either receptor, including some dichlorodiphenyltrichloroethane (DDT) metabolites and trans-nonachlor, appeared to have higher affinity for aERalpha than hERalpha. p,p'-Dicofol-mediated transcriptional activation through aERalpha and hERalpha was assessed to further explore the preferential binding of p,p'-dicofol to aERalpha over hERalpha. p,p'-Dicofol was able to stimulate transcriptional activation in a similar manner with both receptors. However, the in vitro results obtained with p,p'-dicofol were not reflected in an in vivo mammalian model, where Kelthane (mixed o,p'- and p,p'-dicofol isomers) did not elicit estrogenic effects. In conclusion, although there was no evidence of exclusively species-specific estrogen receptor binders, some xenoestrogens, especially p,p'-dicofol, had a higher affinity for aERalpha than for hERalpha.
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Affiliation(s)
- Cynthia V. Rider
- Department of Molecular Biomedical Sciences, North Carolina State University, 4700 Hillsborough Street, Raleigh, North Carolina 27606, USA
| | - Phillip C. Hartig
- Reproductive Toxicology Branch, Toxicity Assessment Division, U.S. Environmental Protection Agency, MD-72, Research Triangle Park, North Carolina 27711
| | - Mary C. Cardon
- Reproductive Toxicology Branch, Toxicity Assessment Division, U.S. Environmental Protection Agency, MD-72, Research Triangle Park, North Carolina 27711
| | - Christy R. Lambright
- Reproductive Toxicology Branch, Toxicity Assessment Division, U.S. Environmental Protection Agency, MD-72, Research Triangle Park, North Carolina 27711
| | - Kathy L. Bobseine
- Reproductive Toxicology Branch, Toxicity Assessment Division, U.S. Environmental Protection Agency, MD-72, Research Triangle Park, North Carolina 27711
| | - Louis J. Guillette
- Department of Biology, University of Florida, 220 Bartram Hall, PO Box 118525, Gainesville, Florida 32611-8525, USA
| | - L. Earl Gray
- Reproductive Toxicology Branch, Toxicity Assessment Division, U.S. Environmental Protection Agency, MD-72, Research Triangle Park, North Carolina 27711
| | - Vickie S. Wilson
- Reproductive Toxicology Branch, Toxicity Assessment Division, U.S. Environmental Protection Agency, MD-72, Research Triangle Park, North Carolina 27711
- To whom correspondence may be addressed ()
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Rider CV, Hartig PC, Cardon MC, Wilson VS. Comparison of chemical binding to recombinant fathead minnow and human estrogen receptors alpha in whole cell and cell-free binding assays. Environ Toxicol Chem 2009; 28:2175-2181. [PMID: 19453209 DOI: 10.1897/09-018.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Accepted: 04/27/2009] [Indexed: 05/25/2023]
Abstract
Mammalian receptors and assay systems are generally used for in vitro screening of endocrine-disrupting chemicals with the assumption that minor differences in amino acid sequences among species do not translate into significant differences in receptor function. Objectives of the present study were to evaluate the performance of two different in vitro assay systems (a whole cell and a cell-free competitive binding assay) in assessing whether binding of chemicals differs significantly between full-length recombinant estrogen receptors from fathead minnows (fhERalpha) and those from humans (hERalpha). It was confirmed that 17beta-estradiol displays a reduction in binding to fhERalpha at an elevated temperature (37 degrees C), as has been reported with other piscine estrogen receptors. Several of the chemicals (17beta-estradiol, ethinylestradiol, alpha-zearalanol, fulvestrant, dibutyl phthalate, benzyl butyl phthalate, and cadmium chloride) displayed higher affinity for fhERalpha than for hERalpha in the whole cell assay, while only dibutyl phthalate had a higher affinity for fhERalpha than for hERalpha in the cell-free assay. Both assays were effective in identifying strong binders, weak binders, and nonbinders to the two receptors. However, the cell-free assay provided a less complicated and more efficient binding platform and is, therefore, recommended over the whole cell binding assay. In conclusion, no strong evidence showed species-specific binding among the chemicals tested.
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Affiliation(s)
- Cynthia V Rider
- Department of Molecular Biomedical Sciences, North Carolina State University, 4700 Hillsborough Street, Raleigh, North Carolina 27606, USA
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Gray LE, Rider CV, Howdeshell KL, Hotchkiss AK, Wilson VS, Foster PMD, Furr J. Cumulative Effects of Administration Mixtures of "Antiandrogens" in Rats: A New Framework Based upon Common Systems Rather Than Common Mechanisms. Biol Reprod 2009. [DOI: 10.1093/biolreprod/81.s1.634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Blystone CR, Lambright CS, Cardon MC, Furr J, Rider CV, Hartig PC, Wilson VS, Gray LE. Cumulative and Antagonistic Effects of a Mixture of the Antiandrogens Vinclozolin and Iprodione in the Pubertal Male Rat. Toxicol Sci 2009; 111:179-88. [DOI: 10.1093/toxsci/kfp137] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Rider CV, Wilson VS, Howdeshell KL, Hotchkiss AK, Furr JR, Lambright CR, Earl Gray L. Cumulative Effects of In Utero Administration of Mixtures of “Antiandrogens” on Male Rat Reproductive Development. Toxicol Pathol 2009; 37:100-13. [DOI: 10.1177/0192623308329478] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Although risk assessments are typically conducted on a chemical-by-chemical basis, the 1996 Food Quality Protection Act (FQPA) required the Environmental Protection Agency (EPA) to consider cumulative risk of chemicals that act via a common mechanism of toxicity. To this end, we are conducting studies with mixtures to provide a framework for assessing the cumulative effects of “antiandrogenic” chemicals. Rats were dosed during pregnancy with antiandrogens singly or in pairs at dosage levels equivalent to about one half of the ED50 for hypospadias or epididymal agenesis. The pairs include: AR antagonists (vinclozolin plus procymidone), phthalate esters (DBP plus BBP and DEHP plus DBP), a phthalate ester plus an AR antagonist (DBP plus procymidone), and linuron plus BBP. We predicted that each chemical by itself would induce few malformations; however, by mixing any two chemicals together, about 50% of the males would be malformed. All binary combinations produced cumulative, dose-additive effects on the androgen-dependent tissues. We also conducted a mixture study combining seven “antiandrogens” together. These chemicals elicit antiandrogenic effects at two different sites in the androgen signaling pathway (i.e., AR antagonist or inhibition of androgen synthesis). In this study, the complex mixture behaved in a dose-additive manner. Our results indicate that compounds that act by disparate mechanisms of toxicity display cumulative, dose-additive effects when present in combination.
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Affiliation(s)
- Cynthia V. Rider
- MD-72, Endocrinology Branch, Reproductive Toxicology
Division, North Carolina State University/USEPA Cooperative Training
Grant (CT826512010), Raleigh, North Carolina, USA
| | | | | | - Andrew K. Hotchkiss
- MD-72, Endocrinology Branch, Reproductive Toxicology
Division, North Carolina State University/USEPA Cooperative Training
Grant (CT826512010), Raleigh, North Carolina, USA
| | | | | | - L. Earl Gray
- MD-72, Endocrinology Branch, Reproductive Toxicology
Division,
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Howdeshell KL, Rider CV, Wilson VS, Gray LE. Mechanisms of action of phthalate esters, individually and in combination, to induce abnormal reproductive development in male laboratory rats. Environ Res 2008; 108:168-76. [PMID: 18949836 DOI: 10.1016/j.envres.2008.08.009] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Phthalate esters are high production volume chemicals used to impart flexibility to polyvinyl chloride products as well as other applications. In the male laboratory rat, the period of sexual differentiation in utero is particularly sensitive to certain phthalate esters, which induce a suite of reproductive malformations, including epididymal and gubernacular agenesis. The fetal rat testes are a main target for phthalate esters as evidenced by a reduction in testosterone production and insulin-like hormone 3 (insl3) expression, a peptide hormone critical for testis descent. Histopathology of fetal and postnatal testes reveals that in utero exposure to phthalate esters disrupts Leydig and Sertoli cell maturation leading to a reduction in germ cells in the malformed seminiferous tubules in adulthood as well as an increased incidence of multinucleated germ cells. There are some strain-specific differences in the target organs in the male reproductive tract in rats affected by phthalate esters. Mixtures of phthalate esters with one another and with other anti-androgenic compounds exhibit cumulative, largely dose-additive effects on male reproductive tract development when administered during sexual differentiation in utero. Since phthalate ester metabolites are detected in maternal and fetal body fluids, and androgen-signaling and insl3 are highly conserved among mammals, phthalates may potentially affect human reproductive development.
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Affiliation(s)
- Kembra L Howdeshell
- Reproductive Toxicology Division, National Health and Environmental Effects Laboratory, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
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Howdeshell KL, Wilson VS, Furr J, Lambright CR, Rider CV, Blystone CR, Hotchkiss AK, Gray LE. A Mixture of Five Phthalate Esters Inhibits Fetal Testicular Testosterone Production in the Sprague-Dawley Rat in a Cumulative, Dose-Additive Manner. Toxicol Sci 2008; 105:153-65. [DOI: 10.1093/toxsci/kfn077] [Citation(s) in RCA: 329] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Wilson VS, Blystone CR, Hotchkiss AK, Rider CV, Gray LE. Diverse mechanisms of anti-androgen action: impact on male rat reproductive tract development. ACTA ACUST UNITED AC 2008; 31:178-87. [DOI: 10.1111/j.1365-2605.2007.00861.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hotchkiss AK, Rider CV, Blystone CR, Wilson VS, Hartig PC, Ankley GT, Foster PM, Gray CL, Gray LE. Fifteen years after "Wingspread"--environmental endocrine disrupters and human and wildlife health: where we are today and where we need to go. Toxicol Sci 2008; 105:235-59. [PMID: 18281716 DOI: 10.1093/toxsci/kfn030] [Citation(s) in RCA: 326] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In 1991, a group of expert scientists at a Wingspread work session on endocrine-disrupting chemicals (EDCs) concluded that "Many compounds introduced into the environment by human activity are capable of disrupting the endocrine system of animals, including fish, wildlife, and humans. Endocrine disruption can be profound because of the crucial role hormones play in controlling development." Since that time, there have been numerous documented examples of adverse effects of EDCs in invertebrates, fish, wildlife, domestic animals, and humans. Hormonal systems can be disrupted by numerous different anthropogenic chemicals including antiandrogens, androgens, estrogens, AhR agonists, inhibitors of steroid hormone synthesis, antithyroid substances, and retinoid agonists. In addition, pathways and targets for endocrine disruption extend beyond the traditional estrogen/androgen/thyroid receptor-mediated reproductive and developmental systems. For example, scientists have expressed concern about the potential role of EDCs in increasing trends in early puberty in girls, obesity and type II diabetes in the United States and other populations. New concerns include complex endocrine alterations induced by mixtures of chemicals, an issue broadened due to the growing awareness that EDCs present in the environment include a variety of potent human and veterinary pharmaceutical products, personal care products, nutraceuticals and phytosterols. In this review we (1) address what have we learned about the effects of EDCs on fish, wildlife, and human health, (2) discuss representative animal studies on (anti)androgens, estrogens and 2,3,7,8-tetrachlorodibenzo-p-dioxin-like chemicals, and (3) evaluate regulatory proposals being considered for screening and testing these chemicals.
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Affiliation(s)
- Andrew K Hotchkiss
- USEPA/NCSU Cooperative Training agreement (CT826512010), Raleigh, North Carolina 27695, USA
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