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Schrenk D, Allemang A, Fahrer J, Harms H, Li X, Lin G, Mahony C, Mulder P, Peijnenburg A, Pfuhler S, Punt A, Sievers H, Troutman J, Widjaja F. Toxins in Botanical Drugs and Plant-derived Food and Feed - from Science to Regulation: A Workshop Review. PLANTA MEDICA 2024; 90:219-242. [PMID: 38198805 DOI: 10.1055/a-2218-5667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
In September 2022, the 3rd International Workshop on pyrrolizidine alkaloids (PAs) and related phytotoxins was held on-line, entitled 'Toxins in botanical drugs and plant-derived food and feed - from science to regulation'. The workshop focused on new findings about the occurrence, exposure, toxicity, and risk assessment of PAs. In addition, new scientific results related to the risk assessment of alkenylbenzenes, a distinct class of herbal constituents, were presented. The presence of PAs and alkenylbenzenes in plant-derived food, feed, and herbal medicines has raised health concerns with respect to their acute and chronic toxicity but mainly related to the genotoxic and carcinogenic properties of several congeners. The compounds are natural constituents of a variety of plant families and species widely used in medicinal, food, and feed products. Their individual occurrence, levels, and toxic properties, together with the broad range of congeners present in nature, represent a striking challenge to modern toxicology. This review tries to provide an overview of the current knowledge on these compounds and indicates needs and perspectives for future research.
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Affiliation(s)
- Dieter Schrenk
- Food Chemistry and Toxicology, RPTU Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Ashley Allemang
- Central Product Safety, The Procter & Gamble Company, Mason, USA
| | - Jörg Fahrer
- Food Chemistry and Toxicology, RPTU Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Henrik Harms
- Federal Institute for Drugs and Medical Devices (BfArM), Bonn, Germany
| | - Xilin Li
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, U. S. Food and Drug Administration, Jefferson, USA
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR
| | - Catherine Mahony
- Central Product Safety, Procter & Gamble Technical Centre, Reading, United Kingdom
| | - Patrick Mulder
- Wageningen Food Safety Research, Wageningen University & Research, Wageningen, the Netherlands
| | - Ad Peijnenburg
- Wageningen Food Safety Research, Wageningen University & Research, Wageningen, the Netherlands
| | - Stefan Pfuhler
- Central Product Safety, The Procter & Gamble Company, Mason, USA
| | - Ans Punt
- Wageningen Food Safety Research, Wageningen University & Research, Wageningen, the Netherlands
| | | | - John Troutman
- Central Product Safety, The Procter & Gamble Company, Mason, USA
| | - Frances Widjaja
- Division of Toxicology, Wageningen University & Research, Wageningen, the Netherlands
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Pedroni L, Louisse J, Dorne JLCM, Dall'Asta C, Dellafiora L. A computational study on the biotransformation of alkenylbenzenes by a selection of CYPs: Reflections on their possible bioactivation. Toxicology 2023; 488:153471. [PMID: 36863505 DOI: 10.1016/j.tox.2023.153471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/23/2023] [Accepted: 02/27/2023] [Indexed: 03/03/2023]
Abstract
Alkenylbenzenes are aromatic compounds found in several vegetable foods that can cause genotoxicity upon bioactivation by members of the cytochrome P450 (CYP) family, forming 1'-hydroxy metabolites. These intermediates act as proximate carcinogens and can be further converted into reactive 1'-sulfooxy metabolites, which are the ultimate carcinogens responsible for genotoxicity. Safrole, a member of this class, has been banned as a food or feed additive in many countries based on its genotoxicity and carcinogenicity. However, it can still enter the food and feed chain. There is limited information about the toxicity of other alkenylbenzenes that may be present in safrole-containing foods, such as myristicin, apiole, and dillapiole. In vitro studies showed safrole as mainly bioactivated by CYP2A6 to form its proximate carcinogen, while for myristicin this is mainly done by CYP1A1. However, it is not known whether CYP1A1 and CYP2A6 can activate apiole and dillapiole. The present study uses an in silico pipeline to investigate this knowledge gap and determine whether CYP1A1 and CYP2A6 may play a role in the bioactivation of these alkenylbenzenes. The study found that the bioactivation of apiole and dillapiole by CYP1A1 and CYP2A6 is limited, possibly indicating that these compounds may have limited toxicity, while describing a possible role of CYP1A1 in the bioactivation of safrole. The study expands the current understanding of safrole toxicity and bioactivation and helps understand the mechanisms of CYPs involved in the bioactivation of alkenylbenzenes. This information is essential for a more informed analysis of alkenylbenzenes toxicity and risk assessment.
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Affiliation(s)
- Lorenzo Pedroni
- Department of Food and Drug, University of Parma, Parma 43124, Italy
| | - Jochem Louisse
- Wageningen Food Safety Research, P.O. Box 230, 6700 AE Wageningen, the Netherlands
| | | | - Chiara Dall'Asta
- Department of Food and Drug, University of Parma, Parma 43124, Italy
| | - Luca Dellafiora
- Department of Food and Drug, University of Parma, Parma 43124, Italy.
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3
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Astrain-Redin N, Sanmartin C, Sharma AK, Plano D. From Natural Sources to Synthetic Derivatives: The Allyl Motif as a Powerful Tool for Fragment-Based Design in Cancer Treatment. J Med Chem 2023; 66:3703-3731. [PMID: 36858050 PMCID: PMC10041541 DOI: 10.1021/acs.jmedchem.2c01406] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Since the beginning of history, natural products have been an abundant source of bioactive molecules for the treatment of different diseases, including cancer. Many allyl derivatives, which have shown anticancer activity both in vitro and in vivo in a large number of cancers, are bioactive molecules found in garlic, cinnamon, nutmeg, or mustard. In addition, synthetic products containing allyl fragments have been developed showing potent anticancer properties. Of particular note is the allyl derivative 17-AAG, which has been evaluated in Phase I and Phase II/III clinical trials for the treatment of multiple myeloma, metastatic melanoma, renal cancer, and breast cancer. In this Perspective, we compile extensive literature evidence with descriptions and discussions of the most recent advances in different natural and synthetic allyl derivatives that could generate cancer drug candidates in the near future.
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Affiliation(s)
- Nora Astrain-Redin
- Department of Pharmaceutical Technology and Chemistry, University of Navarra, E-31008 Pamplona, Spain
| | - Carmen Sanmartin
- Department of Pharmaceutical Technology and Chemistry, University of Navarra, E-31008 Pamplona, Spain
| | - Arun K Sharma
- Department of Pharmacology, Penn State Cancer Institute, CH72, Penn State College of Medicine, 500 University Drive, Hershey, Pennsylvania 17033, United States
| | - Daniel Plano
- Department of Pharmaceutical Technology and Chemistry, University of Navarra, E-31008 Pamplona, Spain
- Department of Pharmacology, Penn State Cancer Institute, CH72, Penn State College of Medicine, 500 University Drive, Hershey, Pennsylvania 17033, United States
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Davidsen JM, Cohen SM, Eisenbrand G, Fukushima S, Gooderham NJ, Guengerich FP, Hecht SS, Rietjens IMCM, Rosol TJ, Harman CL, Taylor SV. FEMA GRAS assessment of derivatives of basil, nutmeg, parsley, tarragon and related allylalkoxybenzene-containing natural flavor complexes. Food Chem Toxicol 2023; 175:113646. [PMID: 36804339 DOI: 10.1016/j.fct.2023.113646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/26/2023] [Accepted: 01/30/2023] [Indexed: 02/18/2023]
Abstract
In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA) initiated a program for the re-evaluation of the safety of over 250 natural flavor complexes (NFCs) used as flavoring ingredients in food. In this publication, tenth in the series, NFCs containing a high percentage of at least one naturally occurring allylalkoxybenzene constituent with a suspected concern for genotoxicity and/or carcinogenicity are evaluated. In a related paper, ninth in the series, NFCs containing anethole and/or eugenol and relatively low percentages of these allylalkoxybenzenes are evaluated. The Panel applies the threshold of toxicological concern (TTC) concept and evaluates relevant toxicology data on the NFCs and their respective constituent congeneric groups. For NFCs containing allylalkoxybenzene constituent(s), the estimated intake of the constituent is compared to the TTC for compounds with structural alerts for genotoxicity and when exceeded, a margin of exposure (MOE) is calculated. BMDL10 values are derived from benchmark dose analyses using Bayesian model averaging for safrole, estragole and methyl eugenol using EPA's BMDS software version 3.2. BMDL10 values for myristicin, elemicin and parsley apiole were estimated by read-across using relative potency factors. Margins of safety for each constituent congeneric group and MOEs for each allylalkoxybenzene constituent for each NFC were determined that indicate no safety concern. The scope of the safety evaluation contained herein does not include added use in dietary supplements or any products other than food. Ten NFCs, derived from basil, estragon (tarragon), mace, nutmeg, parsley and Canadian snakeroot were determined or affirmed as generally recognized as safe (GRAS) under their conditions of intended use as flavor ingredients based on an evaluation of each NFC and the constituents and congeneric groups therein.
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Affiliation(s)
- Jeanne M Davidsen
- Flavor and Extract Manufacturers Association, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA
| | - Samuel M Cohen
- Havlik-Wall Professor of Oncology, Dept. of Pathology and Microbiology, University of Nebraska Medical Center, 983135 Nebraska Medical Center, Omaha, NE, 68198-3135, USA
| | - Gerhard Eisenbrand
- University of Kaiserslautern, Germany (Retired), Kühler Grund 48/1, 69126, Heidelberg, Germany
| | - Shoji Fukushima
- Japan Bioassay Research Center, 2445 Hirasawa, Hadano, Kanagawa, 257-0015, Japan
| | - Nigel J Gooderham
- Dept. of Metabolism, Digestion, Reproduction, Imperial College London, Sir Alexander Fleming Building, London, SW7 2AZ, United Kingdom
| | - F Peter Guengerich
- Dept. of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232-0146, USA
| | - Stephen S Hecht
- Masonic Cancer Center and Dept. of Laboratory Medicine and Pathology, Cancer and Cardiovascular Research Building, 2231 6th St, S.E, Minneapolis, MN, 55455, USA
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Stippeneng 6708 WE, Wageningen, the Netherlands
| | - Thomas J Rosol
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, 1 Ohio University, Athens, OH, 45701, USA
| | - Christie L Harman
- Flavor and Extract Manufacturers Association, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA
| | - Sean V Taylor
- Scientific Secretary to the FEMA Expert Panel, 1101 17th Street, N.W., Suite 700, Washington, D.C, 20036, USA.
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Pedroni L, Louisse J, Punt A, Dorne JLCM, Dall’Asta C, Dellafiora L. A Computational Inter-Species Study on Safrole Phase I Metabolism-Dependent Bioactivation: A Mechanistic Insight into the Study of Possible Differences among Species. Toxins (Basel) 2023; 15:toxins15020094. [PMID: 36828409 PMCID: PMC9962551 DOI: 10.3390/toxins15020094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Safrole, a 162.2 Da natural compound belonging to the alkenylbenzenes class, is classified as a possible carcinogen to humans by IARC (group IIB) and has proven to be genotoxic and carcinogenic to rodents. Despite its use as a food or feed additive, it is forbidden in many countries due to its documented toxicity; yet, it is still broadly present within food and feed and is particularly abundant in spices, herbs and essential oils. Specifically, safrole may exert its toxicity upon bioactivation to its proximate carcinogen 1'-hydroxy-safrole via specific members of the cytochrome P450 protein family with a certain inter/intra-species variability. To investigate this variability, an in-silico workflow based on molecular modelling, docking and molecular dynamics has been successfully applied. This work highlighted the mechanistic basis underpinning differences among humans, cats, chickens, goats, sheep, dogs, mice, pigs, rats and rabbits. The chosen metric to estimate the likeliness of formation of 1'-hydroxy-safrole by the species-specific cytochrome P450 under investigation allowed for the provision of a knowledge-based ground to rationally design and prioritise further experiments and deepen the current understanding of alkenylbenzenes bioactivation and CYPs mechanics. Both are crucial for a more informed framework of analysis for safrole toxicity.
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Affiliation(s)
- Lorenzo Pedroni
- Department of Food and Drug, University of Parma, 43124 Parma, Italy
| | - Jochem Louisse
- Wageningen Food Safety Research, P.O. Box 230, 6700 AE Wageningen, The Netherlands
| | - Ans Punt
- Wageningen Food Safety Research, P.O. Box 230, 6700 AE Wageningen, The Netherlands
| | - Jean Lou C. M. Dorne
- Methodology and Scientific Support Unit (MESE), European Food Safety Authority, 43126 Parma, Italy
| | - Chiara Dall’Asta
- Department of Food and Drug, University of Parma, 43124 Parma, Italy
| | - Luca Dellafiora
- Department of Food and Drug, University of Parma, 43124 Parma, Italy
- Correspondence: ; Tel.: +39-0521-906079
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Kobets T, Smith BPC, Williams GM. Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk. Foods 2022; 11:foods11182828. [PMID: 36140952 PMCID: PMC9497933 DOI: 10.3390/foods11182828] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/16/2022] Open
Abstract
Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.
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Affiliation(s)
- Tetyana Kobets
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA
- Correspondence: ; Tel.: +1-914-594-3105; Fax: +1-914-594-4163
| | - Benjamin P. C. Smith
- Future Ready Food Safety Hub, Nanyang Technological University, Singapore 639798, Singapore
| | - Gary M. Williams
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA
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Myristicin and Elemicin: Potentially Toxic Alkenylbenzenes in Food. Foods 2022; 11:foods11131988. [PMID: 35804802 PMCID: PMC9265716 DOI: 10.3390/foods11131988] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 06/22/2022] [Accepted: 07/01/2022] [Indexed: 11/17/2022] Open
Abstract
Alkenylbenzenes represent a group of naturally occurring substances that are synthesized as secondary metabolites in various plants, including nutmeg and basil. Many of the alkenylbenzene-containing plants are common spice plants and preparations thereof are used for flavoring purposes. However, many alkenylbenzenes are known toxicants. For example, safrole and methyleugenol were classified as genotoxic carcinogens based on extensive toxicological evidence. In contrast, reliable toxicological data, in particular regarding genotoxicity, carcinogenicity, and reproductive toxicity is missing for several other structurally closely related alkenylbenzenes, such as myristicin and elemicin. Moreover, existing data on the occurrence of these substances in various foods suffer from several limitations. Together, the existing data gaps regarding exposure and toxicity cause difficulty in evaluating health risks for humans. This review gives an overview on available occurrence data of myristicin, elemicin, and other selected alkenylbenzenes in certain foods. Moreover, the current knowledge on the toxicity of myristicin and elemicin in comparison to their structurally related and well-characterized derivatives safrole and methyleugenol, especially with respect to their genotoxic and carcinogenic potential, is discussed. Finally, this article focuses on existing data gaps regarding exposure and toxicity currently impeding the evaluation of adverse health effects potentially caused by myristicin and elemicin.
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In vitro and in silico study on consequences of combined exposure to the food-borne alkenylbenzenes estragole and safrole. Toxicol In Vitro 2021; 79:105290. [PMID: 34861381 DOI: 10.1016/j.tiv.2021.105290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 11/20/2021] [Accepted: 11/28/2021] [Indexed: 11/22/2022]
Abstract
Potential consequences of combined exposure to the selected food-borne alkenylbenzenes safrole and estragole or their proximate carcinogenic 1'-hydroxy metabolites were evaluated in vitro and in silico. HepG2 cells were exposed to 1'-hydroxyestragole and 1'-hydroxysafrole individually or in equipotent combination subsequently detecting cytotoxicity and DNA adduct formation. Results indicate that concentration addition adequately describes the cytotoxic effects and no statistically significant differences were shown in the level of formation of the major DNA adducts. Furthermore, physiologically based kinetic modeling revealed that at normal dietary intake the concentration of the parent compounds and their 1'-hydroxymetabolites remain substantially below the Km values for the respective bioactivation and detoxification reactions providing further support for the fact that the simultaneous presence of the two carcinogens or of their proximate carcinogenic 1'-hydroxy metabolites may not affect their DNA adduct formation. Overall, these results point at the absence of interactions upon combined exposure to selected food-borne alkenylbenzenes at realistic dietary levels of intake.
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Alkenylbenzenes in Foods: Aspects Impeding the Evaluation of Adverse Health Effects. Foods 2021; 10:foods10092139. [PMID: 34574258 PMCID: PMC8469824 DOI: 10.3390/foods10092139] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/03/2021] [Accepted: 09/07/2021] [Indexed: 12/15/2022] Open
Abstract
Alkenylbenzenes are naturally occurring secondary plant metabolites, primarily present in different herbs and spices, such as basil or fennel seeds. Thus, alkenylbenzenes, such as safrole, methyleugenol, and estragole, can be found in different foods, whenever these herbs and spices (or extracts thereof) are used for food production. In particular, essential oils or other food products derived from the aforementioned herbs and spices, such as basil-containing pesto or plant food supplements, are often characterized by a high content of alkenylbenzenes. While safrole or methyleugenol are known to be genotoxic and carcinogenic, the toxicological relevance of other alkenylbenzenes (e.g., apiol) regarding human health remains widely unclear. In this review, we will briefly summarize and discuss the current knowledge and the uncertainties impeding a conclusive evaluation of adverse effects to human health possibly resulting from consumption of foods containing alkenylbenzenes, especially focusing on the genotoxic compounds, safrole, methyleugenol, and estragole.
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Assessment of the predictive capacity of a physiologically based kinetic model using a read-across approach. ACTA ACUST UNITED AC 2021; 18:100159. [PMID: 34027243 PMCID: PMC8130669 DOI: 10.1016/j.comtox.2021.100159] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 11/26/2022]
Abstract
Potential regulatory application of PBK modelling information to assist read-across. Presents workflow to read across PBK model information from data-rich to data-poor chemicals. Describes appropriate analogue selection based on a set of specific criteria. Uses estragole and safrole as source chemicals for a target chemical - methyleugenol. Example of PBK model validation where in vivo kinetic data are lacking.
With current progress in science, there is growing interest in developing and applying Physiologically Based Kinetic (PBK) models in chemical risk assessment, as knowledge of internal exposure to chemicals is critical to understanding potential effects in vivo. In particular, a new generation of PBK models is being developed in which the model parameters are derived from in silico and in vitro methods. To increase the acceptance and use of these “Next Generation PBK models”, there is a need to demonstrate their validity. However, this is challenging in the case of data-poor chemicals that are lacking in kinetic data and for which predictive capacity cannot, therefore, be assessed. The aim of this work is to lay down the fundamental steps in using a read across framework to inform modellers and risk assessors on how to develop, or evaluate, PBK models for chemicals without in vivo kinetic data. The application of a PBK model that takes into account the absorption, distribution, metabolism and excretion characteristics of the chemical reduces the uncertainties in the biokinetics and biotransformation of the chemical of interest. A strategic flow-charting application, proposed herein, allows users to identify the minimum information to perform a read-across from a data-rich chemical to its data-poor analogue(s). The workflow analysis is illustrated by means of a real case study using the alkenylbenzene class of chemicals, showing the reliability and potential of this approach. It was demonstrated that a consistent quantitative relationship between model simulations could be achieved using models for estragole and safrole (source chemicals) when applied to methyleugenol (target chemical). When the PBK model code for the source chemicals was adapted to utilise input values relevant to the target chemical, simulation was consistent between the models. The resulting PBK model for methyleugenol was further evaluated by comparing the results to an existing, published model for methyleugenol, providing further evidence that the approach was successful. This can be considered as a “read-across” approach, enabling a valid PBK model to be derived to aid the assessment of a data poor chemical.
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Abstract
The cytosolic sulfotransferase (SULT) enzymes are found in human liver, kidney, intestine, and other tissues. These enzymes catalyze the transfer of the -SO3 group from 3'-phospho-adenosyl-5'-phosphosulfate (PAPS) to a nucleophilic hydroxyl or amine group in a drug substrate. SULTs are stable as dimers, with a highly conserved dimerization domain near the C-terminus of the protein. Crystal structures have revealed flexible loop regions in the native proteins, one of which, located near the dimerization domain, is thought to form a gate that changes position once PAPS is bound to the PAPS-binding site and modulates substrate access and enzyme properties. There is also evidence that oxidation and reduction of certain cysteine residues reversibly regulate the binding of the substrate and PAPS or PAP to the enzyme thus modulating sulfonation. Because SULT enzymes have two substrates, the drug and PAPS, it is common to report apparent kinetic constants with either the drug or the PAPS varied while the other is kept at a constant concentration. The kinetics of product formation can follow classic Michaelis-Menten kinetics, typically over a narrow range of substrate concentrations. Over a wide range of substrate concentrations, it is common to observe partial or complete substrate inhibition with SULT enzymes. This chapter describes the function, tissue distribution, structural features, and properties of the human SULT enzymes and presents examples of enzyme kinetics with different substrates.
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Affiliation(s)
- Margaret O James
- Department of Medicinal Chemistry, University of Florida, Gainesville, FL, USA.
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Yang S, Liu JDH, Diem M, Wesseling S, Vervoort J, Oostenbrink C, Rietjens IMCM. Molecular Dynamics and In Vitro Quantification of Safrole DNA Adducts Reveal DNA Adduct Persistence Due to Limited DNA Distortion Resulting in Inefficient Repair. Chem Res Toxicol 2020; 33:2298-2309. [PMID: 32786539 DOI: 10.1021/acs.chemrestox.0c00097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The formation and repair of N2-(trans-isosafrol-3'-yl)-2'-deoxyguanosine (S-3'-N2-dG) DNA adduct derived from the spice and herbal alkenylbenzene constituent safrole were investigated. DNA adduct formation and repair were studied in vitro and using molecular dynamics (MD) simulations. DNA adduct formation was quantified using liquid chromatography-mass spectrometry (LCMS) in wild type and NER (nucleotide excision repair) deficient CHO cells and also in HepaRG cells and primary rat hepatocytes after different periods of repair following exposure to safrole or 1'-hydroxysafrole (1'-OH safrole). The slower repair of the DNA adducts found in NER deficient cells compared to that in CHO wild type cells indicates a role for NER in repair of S-3'-N2-dG DNA adducts. However, DNA repair in liver cell models appeared to be limited, with over 90% of the adducts remaining even after 24 or 48 h recovery. In our further studies, MD simulations indicated that S-3'-N2-dG adduct formation causes only subtle changes in the DNA structure, potentially explaining inefficient activation of NER. Inefficiency of NER mediated repair of S-3'-N2-dG adducts points at persistence and potential bioaccumulation of safrole DNA adducts upon daily dietary exposure.
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Affiliation(s)
- Shuo Yang
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Jakob D H Liu
- Institute of Molecular Modeling and Simulation, Department of Material Sciences and Process Engineering, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Matthias Diem
- Institute of Molecular Modeling and Simulation, Department of Material Sciences and Process Engineering, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Sebastiaan Wesseling
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Jacques Vervoort
- Division of Biochemistry, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Chris Oostenbrink
- Institute of Molecular Modeling and Simulation, Department of Material Sciences and Process Engineering, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
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13
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Hartwig A, Arand M, Epe B, Guth S, Jahnke G, Lampen A, Martus HJ, Monien B, Rietjens IMCM, Schmitz-Spanke S, Schriever-Schwemmer G, Steinberg P, Eisenbrand G. Mode of action-based risk assessment of genotoxic carcinogens. Arch Toxicol 2020; 94:1787-1877. [PMID: 32542409 PMCID: PMC7303094 DOI: 10.1007/s00204-020-02733-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 03/31/2020] [Indexed: 12/16/2022]
Abstract
The risk assessment of chemical carcinogens is one major task in toxicology. Even though exposure has been mitigated effectively during the last decades, low levels of carcinogenic substances in food and at the workplace are still present and often not completely avoidable. The distinction between genotoxic and non-genotoxic carcinogens has traditionally been regarded as particularly relevant for risk assessment, with the assumption of the existence of no-effect concentrations (threshold levels) in case of the latter group. In contrast, genotoxic carcinogens, their metabolic precursors and DNA reactive metabolites are considered to represent risk factors at all concentrations since even one or a few DNA lesions may in principle result in mutations and, thus, increase tumour risk. Within the current document, an updated risk evaluation for genotoxic carcinogens is proposed, based on mechanistic knowledge regarding the substance (group) under investigation, and taking into account recent improvements in analytical techniques used to quantify DNA lesions and mutations as well as "omics" approaches. Furthermore, wherever possible and appropriate, special attention is given to the integration of background levels of the same or comparable DNA lesions. Within part A, fundamental considerations highlight the terms hazard and risk with respect to DNA reactivity of genotoxic agents, as compared to non-genotoxic agents. Also, current methodologies used in genetic toxicology as well as in dosimetry of exposure are described. Special focus is given on the elucidation of modes of action (MOA) and on the relation between DNA damage and cancer risk. Part B addresses specific examples of genotoxic carcinogens, including those humans are exposed to exogenously and endogenously, such as formaldehyde, acetaldehyde and the corresponding alcohols as well as some alkylating agents, ethylene oxide, and acrylamide, but also examples resulting from exogenous sources like aflatoxin B1, allylalkoxybenzenes, 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx), benzo[a]pyrene and pyrrolizidine alkaloids. Additionally, special attention is given to some carcinogenic metal compounds, which are considered indirect genotoxins, by accelerating mutagenicity via interactions with the cellular response to DNA damage even at low exposure conditions. Part C finally encompasses conclusions and perspectives, suggesting a refined strategy for the assessment of the carcinogenic risk associated with an exposure to genotoxic compounds and addressing research needs.
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Affiliation(s)
- Andrea Hartwig
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany.
| | - Michael Arand
- Institute of Pharmacology and Toxicology, University of Zurich, 8057, Zurich, Switzerland
| | - Bernd Epe
- Institute of Pharmacy and Biochemistry, University of Mainz, 55099, Mainz, Germany
| | - Sabine Guth
- Department of Toxicology, IfADo-Leibniz Research Centre for Working Environment and Human Factors, TU Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Gunnar Jahnke
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Alfonso Lampen
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), 10589, Berlin, Germany
| | - Hans-Jörg Martus
- Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Bernhard Monien
- Department of Food Safety, German Federal Institute for Risk Assessment (BfR), 10589, Berlin, Germany
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Simone Schmitz-Spanke
- Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, University of Erlangen-Nuremberg, Henkestr. 9-11, 91054, Erlangen, Germany
| | - Gerlinde Schriever-Schwemmer
- Department of Food Chemistry and Toxicology, Institute of Applied Biosciences (IAB), Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
| | - Pablo Steinberg
- Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Haid-und-Neu-Str. 9, 76131, Karlsruhe, Germany
| | - Gerhard Eisenbrand
- Retired Senior Professor for Food Chemistry and Toxicology, Kühler Grund 48/1, 69126, Heidelberg, Germany.
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Hu L, Wu F, He J, Zhong L, Song Y, Shao H. Cytotoxicity of safrole in HepaRG cells: studies on the role of CYP1A2-mediated ortho-quinone metabolic activation. Xenobiotica 2019; 49:1504-1515. [PMID: 30865484 DOI: 10.1080/00498254.2019.1590882] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Linlin Hu
- The Pharmaceutical Department, Nanjing Zhong-da Hospital, School of Medicine, Southeast University, Nanjing, P.R. China
| | - Fei Wu
- Engineering Research Center of Modern Preparation Technology of TCM of Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China
| | - Jie He
- The Pharmaceutical Department, Nanjing Zhong-da Hospital, School of Medicine, Southeast University, Nanjing, P.R. China
| | - Lingjun Zhong
- The Pharmaceutical Department, Nanjing Zhong-da Hospital, School of Medicine, Southeast University, Nanjing, P.R. China
| | - Yifan Song
- The Pharmaceutical Department, Nanjing Zhong-da Hospital, School of Medicine, Southeast University, Nanjing, P.R. China
| | - Hua Shao
- The Pharmaceutical Department, Nanjing Zhong-da Hospital, School of Medicine, Southeast University, Nanjing, P.R. China
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15
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Suparmi S, Widiastuti D, Wesseling S, Rietjens IMCM. Natural occurrence of genotoxic and carcinogenic alkenylbenzenes in Indonesian jamu and evaluation of consumer risks. Food Chem Toxicol 2018; 118:53-67. [PMID: 29727721 DOI: 10.1016/j.fct.2018.04.059] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 12/15/2022]
Abstract
The consumer risks of jamu, Indonesian traditional herbal medicines, was assessed focussing on the presence of alkenylbenzene containing botanical ingredients. Twenty-three out of 25 samples contained alkenylbenzenes at levels ranging from 3.8 to 440 μg/kg, with methyleugenol being the most frequently encountered alkenylbenzene. The estimated daily intake (EDI) resulting from jamu consumption was estimated to amount to 0.2-171 μg/kg bw/day for individual alkenylbenzenes, to 0.9-203 μg/kg bw/day when adding up all alkenylbenzenes detected, and to 0.9-551 μg/kg bw/day when expressed in methyleugenol equivalents using interim relative potency (REP) factors. The margin of exposure (MOE) values obtained were generally <10,000 indicating a priority for risk management when assuming daily consumption during a lifetime. Using Haber's rule it was estimated that two weeks consumption of these jamu only once would not raise a concern (MOE >10,000). However, when considering use for two weeks every year during a lifetime, 5 samples still raise a concern. It is concluded that the consumption of alkenylbenzene containing jamu can be of concern especially when consumed on a daily basis for longer periods of time on a regular basis.
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Affiliation(s)
- Suparmi Suparmi
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands; Department of Biology, Faculty of Medicine, Universitas Islam Sultan Agung, Jl. Raya Kaligawe KM 4, 50112, Semarang, Indonesia.
| | - Diana Widiastuti
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands; The National Agency for Drug and Food Control (NADFC), Jl. Percetakan Negara No.23, 10560, Jakarta, Indonesia
| | - Sebastiaan Wesseling
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
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16
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Risk assessment of genotoxic and carcinogenic alkenylbenzenes in botanical containing products present on the Chinese market. Food Chem Toxicol 2018; 115:344-357. [DOI: 10.1016/j.fct.2018.03.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/12/2018] [Accepted: 03/13/2018] [Indexed: 12/27/2022]
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17
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Yang AH, Zhang L, Zhi DX, Liu WL, Gao X, He X. Identification and analysis of the reactive metabolites related to the hepatotoxicity of safrole. Xenobiotica 2017; 48:1164-1172. [DOI: 10.1080/00498254.2017.1399227] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Ai-Hong Yang
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China,
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin, P. R. China, and
| | - Lei Zhang
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China,
| | - De-Xian Zhi
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China,
- School of Biotechnology Food Science, Tianjin Key Laboratory of Food and Biotechnology, Tianjin University of Commerce, Tianjin, P. R. China
| | - Wen-Li Liu
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China,
| | - Xue Gao
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China,
| | - Xin He
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, P. R. China,
- Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin, P. R. China, and
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18
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Berggren E, White A, Ouedraogo G, Paini A, Richarz AN, Bois FY, Exner T, Leite S, Grunsven LAV, Worth A, Mahony C. Ab initio chemical safety assessment: A workflow based on exposure considerations and non-animal methods. COMPUTATIONAL TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2017; 4:31-44. [PMID: 29214231 PMCID: PMC5695905 DOI: 10.1016/j.comtox.2017.10.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 12/12/2022]
Abstract
We describe and illustrate a workflow for chemical safety assessment that completely avoids animal testing. The workflow, which was developed within the SEURAT-1 initiative, is designed to be applicable to cosmetic ingredients as well as to other types of chemicals, e.g. active ingredients in plant protection products, biocides or pharmaceuticals. The aim of this work was to develop a workflow to assess chemical safety without relying on any animal testing, but instead constructing a hypothesis based on existing data, in silico modelling, biokinetic considerations and then by targeted non-animal testing. For illustrative purposes, we consider a hypothetical new ingredient x as a new component in a body lotion formulation. The workflow is divided into tiers in which points of departure are established through in vitro testing and in silico prediction, as the basis for estimating a safe external dose in a repeated use scenario. The workflow includes a series of possible exit (decision) points, with increasing levels of confidence, based on the sequential application of the Threshold of Toxicological (TTC) approach, read-across, followed by an "ab initio" assessment, in which chemical safety is determined entirely by new in vitro testing and in vitro to in vivo extrapolation by means of mathematical modelling. We believe that this workflow could be applied as a tool to inform targeted and toxicologically relevant in vitro testing, where necessary, and to gain confidence in safety decision making without the need for animal testing.
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Affiliation(s)
- Elisabet Berggren
- Chemical Safety and Alternative Methods Unit, & EURL ECVAM, Directorate F – Health, Consumers and Reference Materials, Joint Research Centre, European Commission, Ispra, Italy
| | | | | | - Alicia Paini
- Chemical Safety and Alternative Methods Unit, & EURL ECVAM, Directorate F – Health, Consumers and Reference Materials, Joint Research Centre, European Commission, Ispra, Italy
| | - Andrea-Nicole Richarz
- Chemical Safety and Alternative Methods Unit, & EURL ECVAM, Directorate F – Health, Consumers and Reference Materials, Joint Research Centre, European Commission, Ispra, Italy
| | | | | | - Sofia Leite
- Liver Cell Biology Laboratory, Vrije Universiteit Brussel, Brussels, Belgium
| | - Leo A. van Grunsven
- Liver Cell Biology Laboratory, Vrije Universiteit Brussel, Brussels, Belgium
| | - Andrew Worth
- Chemical Safety and Alternative Methods Unit, & EURL ECVAM, Directorate F – Health, Consumers and Reference Materials, Joint Research Centre, European Commission, Ispra, Italy
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19
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Alajlouni AM, Al-Malahmeh AJ, Wesseling S, Kalli M, Vervoort J, Rietjens IMCM. Risk assessment of combined exposure to alkenylbenzenes through consumption of plant food supplements containing parsley and dill. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2017; 34:2201-2211. [PMID: 28580843 DOI: 10.1080/19440049.2017.1338837] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A risk assessment was performed of parsley- and dill-based plant food supplements (PFS) containing apiol and related alkenylbenzenes. First, the levels of the alkenylbenzenes in the PFS and the resulting estimated daily intake (EDI) resulting from use of the PFS were quantified. Since most PFS appeared to contain more than one alkenylbenzene, a combined risk assessment was performed based on equal potency or using a so-called toxic equivalency (TEQ) approach based on toxic equivalency factors (TEFs) for the different alkenylbenzenes. The EDIs resulting from daily PFS consumption amount to 0.74-125 µg kg-1 bw for the individual alkenylbenzenes, 0.74-160 µg kg-1 bw for the sum of the alkenylbenzenes, and 0.47-64 µg kg-1 bw for the sum of alkenylbenzenes when expressed in safrole equivalents. The margins of exposure (MOEs) obtained were generally below 10,000, indicating a priority for risk management if the PFS were to be consumed on a daily basis. Considering short-term use of the PFS, MOEs would increase above 10,000, indicating low priority for risk management. It is concluded that alkenylbenzene intake through consumption of parsley- and dill-based PFS is only of concern when these PFS are used for long periods of time.
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Affiliation(s)
- Abdalmajeed M Alajlouni
- a Aqaba International Laboratories/BENHAYYAN, ASEZA , Aqaba , Jordan.,b Division of Toxicology , Wageningen University , Wageningen , the Netherlands
| | - Amer J Al-Malahmeh
- a Aqaba International Laboratories/BENHAYYAN, ASEZA , Aqaba , Jordan.,b Division of Toxicology , Wageningen University , Wageningen , the Netherlands
| | | | - Marina Kalli
- b Division of Toxicology , Wageningen University , Wageningen , the Netherlands
| | - Jacques Vervoort
- c Laboratory of Biochemistry , Wageningen University , Wageningen , the Netherlands
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20
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Al-Malahmeh AJ, Alajlouni AM, Ning J, Wesseling S, Vervoort J, Rietjens IMCM. Determination and risk assessment of naturally occurring genotoxic and carcinogenic alkenylbenzenes in nutmeg-based plant food supplements. J Appl Toxicol 2017; 37:1254-1264. [DOI: 10.1002/jat.3491] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 04/24/2017] [Accepted: 04/24/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Amer J. Al-Malahmeh
- Division of Toxicology; Wageningen University; Stippeneng 4 6708 WE Wageningen The Netherlands
- Aqaba international laboratories/BENHAYYAN, ASEZA; Aqaba 77110 Jordan
| | - Abdalmajeed M. Alajlouni
- Division of Toxicology; Wageningen University; Stippeneng 4 6708 WE Wageningen The Netherlands
- Aqaba international laboratories/BENHAYYAN, ASEZA; Aqaba 77110 Jordan
| | - Jia Ning
- Division of Toxicology; Wageningen University; Stippeneng 4 6708 WE Wageningen The Netherlands
| | - Sebastiaan Wesseling
- Division of Toxicology; Wageningen University; Stippeneng 4 6708 WE Wageningen The Netherlands
| | - Jacques Vervoort
- Laboratory of Biochemistry; Wageningen University; Stippeneng 4 6708 WE Wageningen The Netherlands
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21
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Ning J, Louisse J, Spenkelink B, Wesseling S, Rietjens IMCM. Study on inter-ethnic human differences in bioactivation and detoxification of estragole using physiologically based kinetic modeling. Arch Toxicol 2017; 91:3093-3108. [PMID: 28357488 PMCID: PMC5562778 DOI: 10.1007/s00204-017-1941-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/21/2017] [Indexed: 12/21/2022]
Abstract
Considering the rapid developments in food safety in the past decade in China, it is of importance to obtain insight into what extent safety and risk assessments of chemicals performed for the Caucasian population apply to the Chinese population. The aim of the present study was to determine physiologically based kinetic (PBK) modeling-based predictions for differences between Chinese and Caucasians in terms of metabolic bioactivation and detoxification of the food-borne genotoxic carcinogen estragole. The PBK models were defined based on kinetic constants for hepatic metabolism derived from in vitro incubations using liver fractions of the two ethnic groups, and used to evaluate the inter-ethnic differences in metabolic activation and detoxification of estragole. The models predicted that at realistic dietary intake levels, only 0.02% of the dose was converted to the ultimate carcinogenic metabolite 1′-sulfooxyestragole in Chinese subjects, whereas this amounted to 0.09% of the dose in Caucasian subjects. Detoxification of 1′-hydroxyestragole, mainly via conversion to 1′-oxoestragole, was similar within the two ethnic groups. The 4.5-fold variation in formation of the ultimate carcinogenic metabolite of estragole accompanied by similar rates of detoxification may indicate a lower risk of estragole for the Chinese population at similar levels of exposure. The study provides a proof of principle for how PBK modeling can identify differences in ethnic sensitivity and provide a more refined risk assessment for a specific ethnic group for a compound of concern.
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Affiliation(s)
- Jia Ning
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
| | - Jochem Louisse
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Bert Spenkelink
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Sebastiaan Wesseling
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
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22
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Physiologically based kinetic modeling of the bioactivation of myristicin. Arch Toxicol 2016; 91:713-734. [PMID: 27334372 PMCID: PMC5306082 DOI: 10.1007/s00204-016-1752-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/08/2016] [Indexed: 11/08/2022]
Abstract
The present study describes physiologically based kinetic (PBK) models for the alkenylbenzene myristicin that were developed by extension of the PBK models for the structurally related alkenylbenzene safrole in rat and human. The newly developed myristicin models revealed that the formation of the proximate carcinogenic metabolite 1′-hydroxymyristicin in liver is at most 1.8 fold higher in rat than in human and limited for the ultimate carcinogenic metabolite 1′-sulfoxymyristicin to (2.8–4.0)-fold higher in human. In addition, a comparison was made between the relative importance of bioactivation for myristicin and safrole. Model predictions indicate that for these related compounds, the formation of the 1′-sulfoxy metabolites in rat and human liver is comparable with a difference of <2.2-fold over a wide dose range. The results from this PBK analysis support that risk assessment of myristicin may be based on the BMDL10 derived for safrole of 1.9–5.1 mg/kg bw per day. Using an estimated daily intake of myristicin of 0.0019 mg/kg bw per day resulting from the use of herbs and spices, this results in MOE values for myristicin that amount to 1000–2700, indicating a priority for risk management. The results obtained illustrate that PBK modeling provides insight into possible species differences in the metabolic activation of myristicin. Moreover, they provide an example of how PBK modeling can facilitate a read-across in risk assessment from a compound for which in vivo toxicity studies are available to a related compound for which tumor data are not reported, thus contributing to alternatives in animal testing.
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23
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Punt A, Paini A, Spenkelink A, Scholz G, Schilter B, van Bladeren PJ, Rietjens IMCM. Evaluation of Interindividual Human Variation in Bioactivation and DNA Adduct Formation of Estragole in Liver Predicted by Physiologically Based Kinetic/Dynamic and Monte Carlo Modeling. Chem Res Toxicol 2016; 29:659-68. [PMID: 26952143 DOI: 10.1021/acs.chemrestox.5b00493] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Estragole is a known hepatocarcinogen in rodents at high doses following metabolic conversion to the DNA-reactive metabolite 1'-sulfooxyestragole. The aim of the present study was to model possible levels of DNA adduct formation in (individual) humans upon exposure to estragole. This was done by extending a previously defined PBK model for estragole in humans to include (i) new data on interindividual variation in the kinetics for the major PBK model parameters influencing the formation of 1'-sulfooxyestragole, (ii) an equation describing the relationship between 1'-sulfooxyestragole and DNA adduct formation, (iii) Monte Carlo modeling to simulate interindividual human variation in DNA adduct formation in the population, and (iv) a comparison of the predictions made to human data on DNA adduct formation for the related alkenylbenzene methyleugenol. Adequate model predictions could be made, with the predicted DNA adduct levels at the estimated daily intake of estragole of 0.01 mg/kg bw ranging between 1.6 and 8.8 adducts in 10(8) nucleotides (nts) (50th and 99th percentiles, respectively). This is somewhat lower than values reported in the literature for the related alkenylbenzene methyleugenol in surgical human liver samples. The predicted levels seem to be below DNA adduct levels that are linked with tumor formation by alkenylbenzenes in rodents, which were estimated to amount to 188-500 adducts per 10(8) nts at the BMD10 values of estragole and methyleugenol. Although this does not seem to point to a significant health concern for human dietary exposure, drawing firm conclusions may have to await further validation of the model's predictions.
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Affiliation(s)
- Ans Punt
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - Alicia Paini
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands.,Nestlé Research Center , P.O. Box 44, 1000 Lausanne 26, Switzerland
| | - Albertus Spenkelink
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - Gabriele Scholz
- Nestlé Research Center , P.O. Box 44, 1000 Lausanne 26, Switzerland
| | - Benoit Schilter
- Nestlé Research Center , P.O. Box 44, 1000 Lausanne 26, Switzerland
| | - Peter J van Bladeren
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands.,Nestec S.A , Avenue Nestlé 55, 1800 Vevey, Switzerland
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University , Tuinlaan 5, 6703 HE Wageningen, The Netherlands
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24
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Alajlouni AM, Al_Malahmeh AJ, Kiwamoto R, Wesseling S, Soffers AE, Al-Subeihi AA, Vervoort J, Rietjens IM. Mode of action based risk assessment of the botanical food-borne alkenylbenzene apiol from parsley using physiologically based kinetic (PBK) modelling and read-across from safrole. Food Chem Toxicol 2016; 89:138-50. [DOI: 10.1016/j.fct.2016.01.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 12/01/2022]
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25
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Rietjens IMCM, Cohen SM, Fukushima S, Gooderham NJ, Hecht S, Marnett LJ, Smith RL, Adams TB, Bastaki M, Harman CG, Taylor SV. Impact of Structural and Metabolic Variations on the Toxicity and Carcinogenicity of Hydroxy- and Alkoxy-Substituted Allyl- and Propenylbenzenes. Chem Res Toxicol 2014; 27:1092-103. [DOI: 10.1021/tx500109s] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- I. M. C. M. Rietjens
- Division
of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE Wageningen, The Netherlands
| | - S. M. Cohen
- Department
of Pathology and Microbiology, University of Nebraska Medical Center, 4400 Emile Street, Omaha, Nebraska 68198, United States
| | - S. Fukushima
- Japan Bioassay Research
Center, 2445, Hirasawa, Hadano-shi, Kanagawa 257-0015, Japan
| | - N. J. Gooderham
- Department
of Surgery and Cancer, Imperial College, London SW7 2AZ, United Kingdom
| | - S. Hecht
- Masonic
Cancer Center and Department of Laboratory Medicine and Pathology, University of Minnesota, MMC 806, 420 Delaware St. SE, Minneapolis, Minnesota 55455, United States
| | - L. J. Marnett
- Department
of Biochemistry, Center in Molecular Toxicology, Vanderbilt University School of Medicine, 1161 21st Avenue S # T1217, Nashville, Tennessee 37232-0146, United States
| | - R. L. Smith
- Molecular
Toxicology, Imperial College, London SW7 2AZ, United Kingdom
| | - T. B. Adams
- Verto Solutions, 1101,
17th Street NW Suite 700, Washington,
D.C. 20036, United States
| | - M. Bastaki
- Verto Solutions, 1101,
17th Street NW Suite 700, Washington,
D.C. 20036, United States
| | - C. G. Harman
- Verto Solutions, 1101,
17th Street NW Suite 700, Washington,
D.C. 20036, United States
| | - S. V. Taylor
- Verto Solutions, 1101,
17th Street NW Suite 700, Washington,
D.C. 20036, United States
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Martati E, Boonpawa R, van den Berg JH, Paini A, Spenkelink A, Punt A, Vervoort J, van Bladeren PJ, Rietjens IM. Malabaricone C-containing mace extract inhibits safrole bioactivation and DNA adduct formation both in vitro and in vivo. Food Chem Toxicol 2014; 66:373-84. [DOI: 10.1016/j.fct.2014.01.043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/21/2014] [Accepted: 01/27/2014] [Indexed: 11/29/2022]
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A physiologically based in silico model for trans-2-hexenal detoxification and DNA adduct formation in human including interindividual variation indicates efficient detoxification and a negligible genotoxicity risk. Arch Toxicol 2013; 87:1725-37. [PMID: 23864024 DOI: 10.1007/s00204-013-1091-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 07/02/2013] [Indexed: 12/23/2022]
Abstract
A number of α,β-unsaturated aldehydes are present in food both as natural constituents and as flavouring agents. Their reaction with DNA due to their electrophilic α,β-unsaturated aldehyde moiety may result in genotoxicity as observed in some in vitro models, thereby raising a safety concern. A question that remains is whether in vivo detoxification would be efficient enough to prevent DNA adduct formation and genotoxicity. In this study, a human physiologically based kinetic/dynamic (PBK/D) model of trans-2-hexenal (2-hexenal), a selected model α,β-unsaturated aldehyde, was developed to examine dose-dependent detoxification and DNA adduct formation in humans upon dietary exposure. The kinetic model parameters for detoxification were quantified using relevant pooled human tissue fractions as well as tissue fractions from 11 different individual subjects. In addition, a Monte Carlo simulation was performed so that the impact of interindividual variation in 2-hexenal detoxification on the DNA adduct formation in the population as a whole could be examined. The PBK/D model revealed that DNA adduct formation due to 2-hexenal exposure was 0.039 adducts/10⁸ nucleotides (nt) at the estimated average 2-hexenal dietary intake (0.04 mg 2-hexenal/kg bw) and 0.18 adducts/10⁸ nt at the 95th percentile of the dietary intake (0.178 mg 2-hexenal/kg bw) in the most sensitive people. These levels are three orders of magnitude lower than natural background DNA adduct levels that have been reported in disease-free humans (6.8-110 adducts/10⁸ nt), suggesting that the genotoxicity risk for the human population at realistic dietary daily intakes of 2-hexenal may be negligible.
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van den Berg SJPL, Punt A, Soffers AEMF, Vervoort J, Ngeleja S, Spenkelink B, Rietjens IMCM. Physiologically based kinetic models for the alkenylbenzene elemicin in rat and human and possible implications for risk assessment. Chem Res Toxicol 2012; 25:2352-67. [PMID: 22992039 DOI: 10.1021/tx300239z] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The present study describes physiologically based kinetic (PBK) models for the alkenylbenzene elemicin (3,4,5-trimethoxyallylbenzene) in rat and human, based on the PBK models previously developed for the structurally related alkenylbenzenes estragole, methyleugenol, and safrole. Using the newly developed models, the level of metabolic activation of elemicin in rat and human was predicted to obtain insight in species differences in the bioactivation of elemicin and read across to the other methoxy allylbenzenes, estragole and methyleugenol. Results reveal that the differences between rat and human in the formation of the proximate carcinogenic metabolite 1'-hydroxyelemicin and the ultimate carcinogenic metabolite 1'-sulfoxyelemicin are limited (<3.8-fold). In addition, a comparison was made between the relative importance of bioactivation for elemicin and that of estragole and methyleugenol. Model predictions indicate that compound differences in the formation of the 1'-sulfoxymetabolites are limited (<11-fold) in rat and human liver. The insights thus obtained were used to perform a risk assessment for elemicin using the margin of exposure (MOE) approach and read across to the other methoxy allylbenzene derivatives for which in vivo animal tumor data are available. This reveals that elemicin poses a lower priority for risk management as compared to its structurally related analogues estragole and methyleugenol. Altogether, the results obtained indicate that PBK modeling provides an important insight in the occurrence of species differences in the metabolic activation of elemicin. Moreover, they provide an example of how PBK modeling can facilitate a read across in risk assessment from compounds for which in vivo toxicity studies are available to a compound for which only limited toxicity data have been described, thus contributing to the development of alternatives for animal testing.
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