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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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Alhejji Y, Widjaja F, Tian S, Hoekstra T, Wesseling S, Rietjens IM. In vitro-in silico study on the influence of dose, fraction bioactivated and endpoint used on the relative potency value of pyrrolizidine alkaloid N-oxides compared to parent pyrrolizidine alkaloids. Curr Res Toxicol 2024; 6:100160. [PMID: 38469320 PMCID: PMC10926302 DOI: 10.1016/j.crtox.2024.100160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/13/2024] Open
Abstract
Pyrrolizidine alkaloids (PAs) and their N-oxides (PA-N-oxides) are phytotoxins found in food, feed and the environment. Yet, limited data exist from which the relative potency of a PA-N-oxide relative to its corresponding PA (REPPANO to PA) can be defined. This study aims to investigate the influence of dose, fraction bioactivated and endpoint on the REPPANO to PA of a series of pyrrolizidine N-oxides using in vitro-in silico data and physiologically based kinetic (PBK) modeling. The first endpoint used to calculate the REPPANO to PA was the ratio of the area under the concentration-time curve of PA resulting from an oral dose of PA-N-oxide divided by that from an equimolar dose of PA (Method 1). The second endpoint was the ratio of the amount of pyrrole-protein adducts formed under these conditions (Method 2). REPPANO to PA values appeared to decrease with increasing dose, with the decrease for Method 2 already starting at lower dose level than for Method 1. At dose levels as low as estimated daily human intakes, REPPANO to PA values amounted to 0.92, 0.81, 0.78, and 0.68 for retrorsine N-oxide, seneciphylline N-oxide, riddelliine N-oxide and senecivernine N-oxide, respectively, and became independent of the dose or fraction bioactivated, because no GSH depletion, saturation of PA clearance or PA-N-oxide reduction occurs. Overall, the results demonstrate the strength of using PBK modeling in defining REPPANO to PA values, thereby substantiating the use of the same approach for other PA-N-oxides for which in vivo data are lacking.
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Affiliation(s)
- Yasser Alhejji
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, the Netherlands
- Department of Food Science and Human Nutrition, College of Agriculture and Veterinary Medicine, Qassim University, Buraydah 51452, Saudi Arabia
| | - Frances Widjaja
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, the Netherlands
| | - Shenghan Tian
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, the Netherlands
| | - Thomas Hoekstra
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, the Netherlands
| | - Sebastiaan Wesseling
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, the Netherlands
| | - Ivonne M.C.M. Rietjens
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, the Netherlands
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Jayawickreme K, Świstak D, Ozimek E, Reszczyńska E, Rysiak A, Makuch-Kocka A, Hanaka A. Pyrrolizidine Alkaloids-Pros and Cons for Pharmaceutical and Medical Applications. Int J Mol Sci 2023; 24:16972. [PMID: 38069294 PMCID: PMC10706944 DOI: 10.3390/ijms242316972] [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: 10/31/2023] [Revised: 11/20/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Heterocyclic organic compounds named pyrrolizidine alkaloids (PAs) belong to a group of alkaloids and are synthesized by either plants or microorganisms. Therefore, they are naturally occurring secondary metabolites. They are found in species applied in the pharmaceutical and food industries, thus a thorough knowledge of their pharmacological properties and toxicology to humans is of great importance for their further safe employment. This review is original because it synthesizes knowledge of plant and microbial PAs, which is unusual in the scientific literature. We have focused on the Boraginaceae family, which is unique due to the exceptional richness and diversity of its PAs in plant species. We have also presented the microbial sources of PAs, both from fungi and bacteria. The structure and metabolism of PAs have been discussed. Our main aim was to summarize the effects of PAs on humans, including both negative, toxic ones, mainly concerning hepatotoxicity and carcinogenicity, as well as potentially positive ones for pharmacological and medical applications. We have collected the results of studies on the anticancer activity of PAs from plant and microbial sources (mainly Streptomyces strains) and on the antimicrobial activity of PAs on different strains of microorganisms (bacteria and fungi). Finally, we have suggested potential applications and future perspectives.
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Affiliation(s)
- Kavindi Jayawickreme
- Student Scientific Club of Phytochemists, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka St. 19, 20-033 Lublin, Poland
| | - Dawid Świstak
- Student Scientific Club of Phytochemists, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka St. 19, 20-033 Lublin, Poland
| | - Ewa Ozimek
- Department of Industrial and Environmental Microbiology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka St. 19, 20-033 Lublin, Poland
| | - Emilia Reszczyńska
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Chodźki St. 1, 20-093 Lublin, Poland
- Department of Plant Physiology and Biophysics, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka St. 19, 20-033 Lublin, Poland
| | - Anna Rysiak
- Department of Botany, Mycology, and Ecology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka St. 19, 20-033 Lublin, Poland
| | - Anna Makuch-Kocka
- Department of Pharmacology, Medical University of Lublin, Radziwiłłowska St. 11, 20-080 Lublin, Poland
| | - Agnieszka Hanaka
- Department of Plant Physiology and Biophysics, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka St. 19, 20-033 Lublin, Poland
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Lin F, Zhao L, Wang Y, Ye Y, Liu J. Comparative Pharmacokinetic Study of Two Pyrrolizidine Alkaloids Lasiocarpine and Heliotrine in Rats. PLANTA MEDICA 2023; 89:571-579. [PMID: 36170857 DOI: 10.1055/a-1915-5456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Lasiocarpine (LAS) and heliotrine (HEL) are two different ester types of toxic pyrrolizidine alkaloids (PAs): open-chain diester and monoester. However, the pharmacokinetics of these two types of PAs in rats have not been reported. In the present study, two LC-MS/MS methods for determining LAS and HEL were established and validated. The methods exhibited good linearity, accuracy, and precision and were then applied to a comparative pharmacokinetic study. After intravenous administration to male rats at 1 mg/kg, the AUC0-t values of LAS and HEL were 336 ± 26 ng/mL × h and 170 ± 5 ng/mL × h. After oral administration at 10 mg/kg, the AUC0-t of LAS was much lower than that of HEL (18.2 ± 3.8 ng/mL × h vs. 396 ± 18 ng/mL × h), while the Cmax of LAS was lower than that of HEL (51.7 ± 22.5 ng/mL × h vs. 320 ± 26 ng/mL × h). The absolute oral bioavailability of LAS was 0.5%, which was significantly lower than that of HEL (23.3%). The results revealed that the pharmacokinetic behaviors of LAS differed from that of HEL.
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Affiliation(s)
- Feifei Lin
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Lijuan Zhao
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yingying Wang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yang Ye
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jia Liu
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
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Widjaja F, Alhejji Y, Rietjens IMCM. The Role of Kinetics as Key Determinant in Toxicity of Pyrrolizidine Alkaloids and Their N-Oxides. PLANTA MEDICA 2022; 88:130-143. [PMID: 34741297 PMCID: PMC8807025 DOI: 10.1055/a-1582-9794] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are a large group of plant constituents of which especially the 1,2- unsaturated PAs raise a concern because of their liver toxicity and potential genotoxic carcinogenicity. This toxicity of PAs depends on their kinetics. Differences in absorption, distribution, metabolism, and excretion (ADME) characteristics of PAs may substantially alter the relative toxicity of PAs. As a result, kinetics will also affect relative potency (REP) values. The present review summarizes the current state-of-the art on PA kinetics and resulting consequences for toxicity and illustrates how physiologically-based kinetic (PBK) modelling can be applied to take kinetics into account when defining the relative differences in toxicity between PAs in the in vivo situation. We conclude that toxicokinetics play an important role in the overall toxicity of pyrrolizidine alkaloids. and that kinetics should therefore be considered when defining REP values for combined risk assessment. New approach methodologies (NAMs) can be of use to quantify these kinetic differences between PAs and their N-oxides, thus contributing to the 3Rs (Replacement, Reduction and Refinement) in animal studies.
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Affiliation(s)
- Frances Widjaja
- Division of Toxicology, Wageningen University and Research, The Netherlands
| | - Yasser Alhejji
- Division of Toxicology, Wageningen University and Research, The Netherlands
- Department of Food Science and Human Nutrition, College of Agriculture and Veterinary Medicine, Qassim University, Buraydah, Saudi Arabia
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Physiologically based kinetic modelling predicts the in vivo relative potency of riddelliine N-oxide compared to riddelliine in rat to be dose dependent. Arch Toxicol 2021; 96:135-151. [PMID: 34669010 PMCID: PMC8748370 DOI: 10.1007/s00204-021-03179-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 10/06/2021] [Indexed: 11/17/2022]
Abstract
Pyrrolizidine alkaloids (PAs) are toxic plant constituents occurring often in their N-oxide form. This raises the question on the relative potency (REP) values of PA-N-oxides compared to the corresponding parent PAs. The present study aims to quantify the in vivo REP value of riddelliine N-oxide compared to riddelliine using physiologically based kinetic (PBK) modelling, taking into account that the toxicity of riddelliine N-oxide depends on its conversion to riddelliine by intestinal microbiota and in the liver. The models predicted a lower Cmax and higher Tmax for the blood concentration of riddelliine upon oral administration of riddelliine N-oxide compared to the Cmax and Tmax predicted for an equimolar oral dose of riddelliine. Comparison of the area under the riddelliine concentration–time curve (AUCRID) obtained upon dosing either the N-oxide or riddelliine itself revealed a ratio of 0.67, which reflects the in vivo REP for riddelliine N-oxide compared to riddelliine, and appeared to closely match the REP value derived from available in vivo data. The models also predicted that the REP value will decrease with increasing dose level, because of saturation of riddelliine N-oxide reduction by the intestinal microbiota and of riddelliine clearance by the liver. It is concluded that PBK modeling provides a way to define in vivo REP values of PA-N-oxides as compared to their parent PAs, without a need for animal experiments.
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Lin F, Ma Y, Pan A, Ye Y, Liu J. Quantification of Usaramine and Its N-oxide Metabolite in Rat Plasma Using Liquid Chromatography-Tandem Mass Spectrometry. J Anal Toxicol 2021; 46:512-518. [PMID: 34086913 PMCID: PMC9122504 DOI: 10.1093/jat/bkab060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/29/2021] [Accepted: 06/03/2021] [Indexed: 11/13/2022] Open
Abstract
A sensitive, fast and robust liquid chromatography--tandem mass spectrometry (LC–MS-MS) method was developed and validated for the determination of usaramine (URM) and usaramine N-oxide (UNO) in rat plasma. The separation was conducted on an ACQUITY UPLC BEH C18 Column (50 × 2.1 mm, 1.7 μm) and gradient eluted with mobile phase A (0.1% formic acid with 5 mM ammonium acetate in water) and B (0.1% formic acid in acetonitrile/methanol, 9/1, v/v). The method was linear over the range of 1–2,000 ng/mL for both analytes. The validated method was applied to investigate the pharmacokinetic behaviors and sex differences of URM and its N-oxide metabolite in rats. After intravenous administration of URM at 1 mg/kg, the AUC0-t values for URM and UNO were 363 ± 65 and 172 ± 32 ng/mL*h in male rats, while 744 ± 122 and 30.7 ± 7.4 ng/mL*h in females, respectively. The clearance of URM was significantly higher in male rats than in females (2.77 ± 0.50 vs 1.35 ± 0.19 L/h/kg, P < 0.05). After oral administration of URM at 10 mg/kg, the AUC0-t values of URM and UNO were 1,960 ± 208 and 1,637 ± 246 ng/mL*h in male rats, while 6,073 ± 488 and 300 ± 62 ng/mL*h in females, respectively. The oral bioavailability of URM in female rats (81.7%) was much higher than in males (54.0%). In conclusion, sex-based differences were observed in the pharmacokinetics, N-oxide metabolism and oral bioavailability of URM.
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Affiliation(s)
- Feifei Lin
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, 138 Xianlin Avenue, Qixia District, Nanjing 210023, China.,Chinese Academy of Sciences, Shanghai Institute of Materia Medica, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Yan Ma
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, 536 Changle Road, Shanghai 200126, China
| | - Anni Pan
- Chinese Academy of Sciences, Shanghai Institute of Materia Medica, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Yang Ye
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, 138 Xianlin Avenue, Qixia District, Nanjing 210023, China.,Chinese Academy of Sciences, Shanghai Institute of Materia Medica, 555 Zuchongzhi Road, Shanghai 201203, China
| | - Jia Liu
- Chinese Academy of Sciences, Shanghai Institute of Materia Medica, 555 Zuchongzhi Road, Shanghai 201203, China
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He Y, Zhu L, Ma J, Lin G. Metabolism-mediated cytotoxicity and genotoxicity of pyrrolizidine alkaloids. Arch Toxicol 2021; 95:1917-1942. [PMID: 34003343 DOI: 10.1007/s00204-021-03060-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/21/2021] [Indexed: 02/06/2023]
Abstract
Pyrrolizidine alkaloids (PAs) and PA N-oxides are common phytotoxins produced by over 6000 plant species. Humans are frequently exposed to PAs via ingestion of PA-containing herbal products or PA-contaminated foods. PAs require metabolic activation to form pyrrole-protein adducts and pyrrole-DNA adducts which lead to cytotoxicity and genotoxicity. Individual PAs differ in their metabolic activation patterns, which may cause significant difference in toxic potency of different PAs. This review discusses the current knowledge and recent advances of metabolic pathways of different PAs, especially the metabolic activation and metabolism-mediated cytotoxicity and genotoxicity, and the risk evaluation methods of PA exposure. In addition, this review provides perspectives of precision toxicity assessment strategies and biomarker development for the risk control and translational investigations of human intoxication by PAs.
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Affiliation(s)
- Yisheng He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Lin Zhu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China.
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Zhang Y, Yang FF, Chen H, Qi YD, Si JY, Wu Q, Liao YH. Analysis of pyrrolizidine alkaloids in Eupatorium fortunei Turcz. and their in vitro neurotoxicity. Food Chem Toxicol 2021; 151:112151. [PMID: 33774095 DOI: 10.1016/j.fct.2021.112151] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 12/11/2022]
Abstract
This study was to analyze the pyrrolizidine alkaloids (PAs) in Eupatorium fortunei herbs and its derived finished products with a view to evaluating their effects on the proliferation and oligodendrogenesis of neural progenitor cells (NPCs). Using a LC-MS/MS method with 32 PAs reference standards, 8 PAs including intermedine, intermedine N-oxide, lycopsamine, lycopsamine N-oxide, retronecine, seneciphylline and senkirkine and 7-acetylintermedine N-oxide were identified with intermedine N-oxide and lycopsamine N-oxide being most abundant. The total PA amounts were found to vary from 0.18 to 61.81 μg/g in 30 batches of herbs and from 0.86 to 36.96 μg/g in 4 commercial finished products, respectively. Risk assessments indicated that the short-term intake seemed unlikely lead to acute toxic effects but the chronic use warranted cautions. Using NPCs derived from mouse induced pluripotent stem cells as an in vitro testing model, intermedine, intermedine N-oxide and lycopsamine N-oxide appeared to decrease cell viability at 30 μM whereas intermedine N-oxide inhibited oligodendrogenesis of NPCs at 10 μM. The present results suggested that the PAs in the majority of E. fortunei herbs and the derived products not only resulted in their exposure far exceeding the acceptable intake limit (i. e. 1.0 μg PA per day for adults) in herbal medicinal products recommended by the European Medicines Agency but also induced neurotoxicity to NPCs in vitro.
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Affiliation(s)
- Yan Zhang
- Beijing University of Chinese Medicine, Yangguang South Street, Fangshan District, Beijing, 102488, PR China; Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Fei-Fei Yang
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Huan Chen
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Yao-Dong Qi
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Jian-Yong Si
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Qing Wu
- Beijing University of Chinese Medicine, Yangguang South Street, Fangshan District, Beijing, 102488, PR China.
| | - Yong-Hong Liao
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China.
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Ning J, Chen L, Rietjens IM. Role of toxicokinetics and alternative testing strategies in pyrrolizidine alkaloid toxicity and risk assessment; state-of-the-art and future perspectives. Food Chem Toxicol 2019; 131:110572. [DOI: 10.1016/j.fct.2019.110572] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 06/05/2019] [Accepted: 06/07/2019] [Indexed: 01/31/2023]
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Muluneh F, Häkkinen MR, El-Dairi R, Pasanen M, Juvonen RO. New glutathione conjugate of pyrrolizidine alkaloids produced by human cytosolic enzyme-dependent reactions in vitro. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:1344-1352. [PMID: 29788543 DOI: 10.1002/rcm.8173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 05/06/2018] [Accepted: 05/11/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE The toxic metabolites of pyrrolizidine alkaloids (PAs) are initially formed by cytochrome P450-mediated oxidation reactions and primarily eliminated as glutathione (GSH) conjugates. Although the reaction between the reactive metabolites and GSH can occur spontaneously, the role of the cytosolic enzymes in the process has not been studied. METHODS The toxic metabolites of selected PAs (retrorsine, monocrotaline, senecionine, lasiocarpine, heliotrine or senkirkine) were generated by incubating them in 100 mM phosphate buffer (pH 7.4) containing liver microsomes of human, pig, rat or sheep, NADPH and reduced GSH in the absence or presence of human, pig, rat or sheep liver cytosolic fraction. The supernatants were analyzed using liquid chromatography connected to Finnigan LTQ ion-trap, Agilent QTOF or Thermo Scientific Q Exactive Focus quadrupole-orbitrap mass spectrometers. RESULTS Retrorsine, senecionine and lasiocarpine yielded three GSH conjugates producing [M - H]- ions at m/z 439 (7-GSH-DHP (CHO)), m/z 441 (7-GSH-DHP (OH)) and m/z 730 (7,9-diGSH-DHP) in the presence of human liver cytosolic fraction. 7-GSH-DHP (CHO) was a novel metabolite. Monocrotaline, heliotrine and senkirkine did not produce this novel 7-GSH-DHP (CHO) conjugate. 7-GSH-DHP (CHO) disappeared when incubated with hydroxylamine, and a new oxime derivative was formed. This metabolite was formed only by the human liver cytosolic enzymes but not in the presence of rat or sheep liver cytosolic fractions under otherwise identical reaction conditions. CONCLUSIONS 7-GSH-DHP (CHO) has not been reported before, and thus it was considered as a novel metabolite of PAs. This may clarify the mechanisms involved in PA detoxification and widely observed but less understood species differences in response to PA exposure.
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Affiliation(s)
- Fashe Muluneh
- University of Eastern Finland, School of Pharmacy, Faculty of Health Sciences, Box 1627, 70211, Kuopio, Finland
- National Institute of Environmental Health Sciences, Reproductive & Developmental Biology Laboratory/Pharmacogenetics Group, NIH, Research Triangle Park, NC, 27709, USA
| | - Merja R Häkkinen
- University of Eastern Finland, School of Pharmacy, Faculty of Health Sciences, Box 1627, 70211, Kuopio, Finland
| | - Rami El-Dairi
- University of Eastern Finland, School of Pharmacy, Faculty of Health Sciences, Box 1627, 70211, Kuopio, Finland
| | - Markku Pasanen
- University of Eastern Finland, School of Pharmacy, Faculty of Health Sciences, Box 1627, 70211, Kuopio, Finland
| | - Risto O Juvonen
- University of Eastern Finland, School of Pharmacy, Faculty of Health Sciences, Box 1627, 70211, Kuopio, Finland
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Chen L, Ning J, Louisse J, Wesseling S, Rietjens IMCM. Use of physiologically based kinetic modelling-facilitated reverse dosimetry to convert in vitro cytotoxicity data to predicted in vivo liver toxicity of lasiocarpine and riddelliine in rat. Food Chem Toxicol 2018; 116:216-226. [PMID: 29634986 DOI: 10.1016/j.fct.2018.04.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/15/2018] [Accepted: 04/05/2018] [Indexed: 01/10/2023]
Abstract
Lasiocarpine and riddelliine are pyrrolizidine alkaloids (PAs) present in food and able to cause liver toxicity. The aim of this study was to investigate whether physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry can adequately translate in vitro concentration-response curves for toxicity of lasiocarpine and riddelliine to in vivo liver toxicity data for the rat. To this purpose, PBK models were developed for lasiocarpine and riddelliine, and predicted blood concentrations were compared to available literature data to evaluate the models. Concentration-response curves obtained from in vitro cytotoxicity assays in primary rat hepatocytes were converted to in vivo dose-response curves from which points of departure (PODs) were derived and that were compared to available literature data on in vivo liver toxicity. The results showed that the predicted PODs fall well within the range of PODs derived from available in vivo toxicity data. To conclude, this study shows the proof-of-principle for a method to predict in vivo liver toxicity for PAs by an alternative testing strategy integrating in vitro cytotoxicity assays with in silico PBK modelling-facilitated reverse dosimetry. The approach may facilitate prediction of acute liver toxicity for the large number of PAs for which in vivo toxicity data are lacking.
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Affiliation(s)
- Lu Chen
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands.
| | - Jia Ning
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands
| | - Jochem Louisse
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands
| | - Sebas Wesseling
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands
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14
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Stegelmeier BL, Colegate SM, Brown AW. Dehydropyrrolizidine Alkaloid Toxicity, Cytotoxicity, and Carcinogenicity. Toxins (Basel) 2016; 8:E356. [PMID: 27916846 PMCID: PMC5198550 DOI: 10.3390/toxins8120356] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 11/22/2016] [Accepted: 11/24/2016] [Indexed: 11/17/2022] Open
Abstract
Dehydropyrrolizidine alkaloid (DHPA)-producing plants have a worldwide distribution amongst flowering plants and commonly cause poisoning of livestock, wildlife, and humans. Previous work has produced considerable understanding of DHPA metabolism, toxicity, species susceptibility, conditions, and routes of exposure, and pathogenesis of acute poisoning. Intoxication is generally caused by contaminated grains, feed, flour, and breads that result in acute, high-dose, short-duration poisoning. Acute poisoning produces hepatic necrosis that is usually confirmed histologically, epidemiologically, and chemically. Less is known about chronic poisoning that may result when plant populations are sporadic, used as tisanes or herbal preparations, or when DHPAs contaminate milk, honey, pollen, or other animal-derived products. Such subclinical exposures may contribute to the development of chronic disease in humans or may be cumulative and probably slowly progress until liver failure. Recent work using rodent models suggest increased neoplastic incidence even with very low DHPA doses of short durations. These concerns have moved some governments to prohibit or limit human exposure to DHPAs. The purpose of this review is to summarize some recent DHPA research, including in vitro and in vivo DHPA toxicity and carcinogenicity reports, and the implications of these findings with respect to diagnosis and prognosis for human and animal health.
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Affiliation(s)
- Bryan L Stegelmeier
- United States Department of Agriculture, Agriculture Research Service, Poisonous Plant Research Laboratory, 1150 East 1400 North, Logan, UT 84341, USA.
| | - Steven M Colegate
- United States Department of Agriculture, Agriculture Research Service, Poisonous Plant Research Laboratory, 1150 East 1400 North, Logan, UT 84341, USA.
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA.
| | - Ammon W Brown
- United States Army Institute of Surgical Research, Ft Sam Houston, TX 78234, USA.
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15
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Fashe MM, Juvonen RO, Petsalo A, Vepsäläinen J, Pasanen M, Rahnasto-Rilla M. In Silico Prediction of the Site of Oxidation by Cytochrome P450 3A4 That Leads to the Formation of the Toxic Metabolites of Pyrrolizidine Alkaloids. Chem Res Toxicol 2015; 28:702-10. [DOI: 10.1021/tx500478q] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Muluneh M. Fashe
- School of Pharmacy, Faculty
of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Risto O. Juvonen
- School of Pharmacy, Faculty
of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Aleksanteri Petsalo
- School of Pharmacy, Faculty
of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Jouko Vepsäläinen
- School of Pharmacy, Faculty
of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Markku Pasanen
- School of Pharmacy, Faculty
of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Minna Rahnasto-Rilla
- School of Pharmacy, Faculty
of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
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Abstract
This review covers pyrrolizidine alkaloids isolated from natural sources. Topics include: aspects of structure, isolation, and biological/pharmacological studies; total syntheses of necic acids, necine bases and closely-related non-natural analogues.
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Affiliation(s)
- Jeremy Robertson
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
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18
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Wang C, Li Y, Gao J, He Y, Xiong A, Yang L, Cheng X, Ma Y, Wang Z. The comparative pharmacokinetics of two pyrrolizidine alkaloids, senecionine and adonifoline, and their main metabolites in rats after intravenous and oral administration by UPLC/ESIMS. Anal Bioanal Chem 2011; 401:275-87. [DOI: 10.1007/s00216-011-5075-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 04/29/2011] [Accepted: 04/29/2011] [Indexed: 11/24/2022]
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19
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Gomes MFPL, de Oliveira Massoco C, Xavier JG, Bonamin LV. Comfrey (Symphytum Officinale. l.) and Experimental Hepatic Carcinogenesis: A Short-term Carcinogenesis Model Study. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2010; 7:197-202. [PMID: 18955295 PMCID: PMC2862927 DOI: 10.1093/ecam/nem172] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Accepted: 09/25/2007] [Indexed: 02/05/2023]
Abstract
Comfrey or Symphytum officinale (L.) (Boraginaceae) is a very popular plant used for therapeutic purposes. Since the 1980s, its effects have been studied in long-term carcinogenesis studies, in which Comfrey extract is administered at high doses during several months and the neoplastic hepatic lesions are evaluated. However, the literature on this topic is very poor considering the studies performed under short-term carcinogenesis protocols, such as the 'resistant hepatocyte model' (RHM). In these studies, it is possible to observe easily the phenomena related to the early phases of tumor development, since pre-neoplastic lesions (PNLs) rise in about 1-2 months of chemical induction. Herein, the effects of chronic oral treatment of rats with 10% Comfrey ethanolic extract were evaluated in a RHM. Wistar rats were sequentially treated with N-nitrosodiethylamine (ip) and 2-acetilaminofluorene (po), and submitted to hepatectomy to induce carcinogenesis promotion. Macroscopic/microscopic quantitative analysis of PNL was performed. Non-parametric statistical tests (Mann-Whitney and χ(2)) were used, and the level of significance was set at P ≤ 0.05. Comfrey treatment reduced the number of pre-neoplastic macroscopic lesions up to 1 mm (P ≤ 0.05), the percentage of oval cells (P = 0.0001) and mitotic figures (P = 0.007), as well as the number of Proliferating Cell Nuclear Antigen (PCNA) positive cells (P = 0.0001) and acidophilic pre-neoplastic nodules (P = 0.05). On the other hand, the percentage of cells presenting megalocytosis (P = 0.0001) and vacuolar degeneration (P = 0.0001) was increased. Scores of fibrosis, glycogen stores and the number of nucleolus organizing regions were not altered. The study indicated that oral treatment of rats with 10% Comfrey alcoholic extract reduced cell proliferation in this model.
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Affiliation(s)
- Maria Fernanda Pereira Lavieri Gomes
- Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, University of Santo Amaro, Oncocell biotecnologia LTDA and Laboratory of Pathology, Health Sciences Institute, University Paulista, São Paulo, Brazil
| | - Cristina de Oliveira Massoco
- Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, University of Santo Amaro, Oncocell biotecnologia LTDA and Laboratory of Pathology, Health Sciences Institute, University Paulista, São Paulo, Brazil
| | - José Guilherme Xavier
- Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, University of Santo Amaro, Oncocell biotecnologia LTDA and Laboratory of Pathology, Health Sciences Institute, University Paulista, São Paulo, Brazil
| | - Leoni Villano Bonamin
- Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, University of Santo Amaro, Oncocell biotecnologia LTDA and Laboratory of Pathology, Health Sciences Institute, University Paulista, São Paulo, Brazil
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20
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Shakeel M, Trinidade A, Ah-See KW. Complementary and alternative medicine use by otolaryngology patients: a paradigm for practitioners in all surgical specialties. Eur Arch Otorhinolaryngol 2009; 267:961-71. [PMID: 19771443 DOI: 10.1007/s00405-009-1098-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Accepted: 09/03/2009] [Indexed: 12/18/2022]
Abstract
There is growing interest in complementary and alternative medicine (CAM) amongst the general population. Little information is available on CAM use in otolaryngology patients in the UK. Despite concerns over safety, efficacy and cost-effectiveness, CAM use is common amongst ENT patients. Patients perceive these medications as possible boosters to their immune system. It is becoming increasingly important that health care providers in all specialties ask their patients about CAM use and are aware of the implications it carries. The objective is to study the prevalence and pattern of CAM use among adult and paediatric ENT patients in a UK teaching hospital. A cross-sectional study was done by sending anonymous questionnaire to all outpatient and elective inpatients over a 3-month period. Response rate was 73% (1,789/2,440). Prominent demographics: female, married, over-50 s. Sixty percent had used CAM, 35% in last year. Most common herbs: cod liver oil (n = 481), garlic (n = 255), cranberry (n = 224); non-herbal: massage (n = 287), acupuncture (n = 233), aromatherapy (n = 170). Most commonly cited reasons for using CAM: general health, enhanced immunity and prevention/treatment of common illnesses like the common cold, asthma and bodily aches and pains.
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Affiliation(s)
- Muhammad Shakeel
- Department of Otolaryngology-Head and Neck Surgery, Aberdeen Royal Infirmary, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZN, Scotland, UK.
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21
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Kempf M, Beuerle T, Bühringer M, Denner M, Trost D, von der Ohe K, Bhavanam VBR, Schreier P. Pyrrolizidine alkaloids in honey: risk analysis by gas chromatography-mass spectrometry. Mol Nutr Food Res 2008; 52:1193-200. [PMID: 18792927 DOI: 10.1002/mnfr.200800051] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Recently, contamination of honey with pyrrolizidine alkaloids (PA) has been reported as potential health risk. Therefore, it was of interest to develop a reliable tool for selective and quantitative determination of PA in honey. Sample preparation of the novel method comprises strong cation exchange SPE (SCX-SPE), followed by two reduction steps using zinc and LiAlH(4), as well as subsequent silylation. During this procedure the separated PA are converted into the necin backbone, the common structural feature of PA toxicity, which is analyzed by GC-MS in the SIM mode. The procedure was validated using PA from extracts of Senecio vernalis as well as authentic PA standards including their corresponding N-oxides. The PA content of honey samples was quantified with heliotrine as internal standard. The method was applied to generate a dataset in order to evaluate the potential risk of PA contamination especially for retail honeys available on the German/European market. No selection criteria in terms of floral or geographical origin were applied on the samples before analysis. In total, 216 commercially available floral honey samples were analyzed. Among them 19 samples contained PA, in the range of 0.019-0.120 microg/g, calculated as retronecine equivalents. The reported method facilitates the selective determination of PA without the need to identify each individual PA independently. The PA contamination of honey is expressed in terms of a single sum parameter and no background information such as foraged plants and pollen analysis is necessary. The LOQ is 0.01 ppm with a S/N of 7:1.
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Affiliation(s)
- Michael Kempf
- Lehrstuhl für Lebensmittelchemie, Universität Würzburg, Würzburg, Germany
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22
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Mei N, Guo L, Liu R, Fuscoe JC, Chen T. Gene expression changes induced by the tumorigenic pyrrolizidine alkaloid riddelliine in liver of Big Blue rats. BMC Bioinformatics 2007; 8 Suppl 7:S4. [PMID: 18047727 PMCID: PMC2099496 DOI: 10.1186/1471-2105-8-s7-s4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Pyrrolizidine alkaloids (PAs) are probably the most common plant constituents that poison livestock, wildlife, and humans worldwide. Riddelliine is isolated from plants grown in the western United States and is a prototype of genotoxic PAs. Riddelliine was used to investigate the genotoxic effects of PAs via analysis of gene expression in the target tissue of rats in this study. Previously we observed that the mutant frequency in the liver of rats gavaged with riddelliine was 3-fold higher than that in the control group. Molecular analysis of the mutants indicated that there was a statistically significant difference between the mutational spectra from riddelliine-treated and control rats. Results Riddelliine-induced gene expression profiles in livers of Big Blue transgenic rats were determined. The female rats were gavaged with riddelliine at a dose of 1 mg/kg body weight 5 days a week for 12 weeks. Rat whole genome microarray was used to perform genome-wide gene expression studies. When a cutoff value of a two-fold change and a P-value less than 0.01 were used as gene selection criteria, 919 genes were identified as differentially expressed in riddelliine-treated rats compared to the control animals. By analysis with the Ingenuity Pathway Analysis Network, we found that these significantly changed genes were mainly involved in cancer, cell death, tissue development, cellular movement, tissue morphology, cell-to-cell signaling and interaction, and cellular growth and proliferation. We further analyzed the genes involved in metabolism, injury of endothelial cells, liver abnormalities, and cancer development in detail. Conclusion The alterations in gene expression were directly related to the pathological outcomes reported previously. These results provided further insight into the mechanisms involved in toxicity and carcinogenesis after exposure to riddelliine, and permitted us to investigate the interaction of gene products inside the signaling networks.
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Affiliation(s)
- Nan Mei
- Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079, USA.
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23
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Opinion of the Panel on contaminants in the food chain [CONTAM] related to pyrrolizidine alkaloids as undesirable substances in animal feed. EFSA J 2007. [DOI: 10.2903/j.efsa.2007.447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Solntsev KM, Clower CE, Tolbert LM, Huppert D. 6-Hydroxyquinoline-N-oxides: A New Class of “Super” Photoacids1. J Am Chem Soc 2005; 127:8534-44. [PMID: 15941289 DOI: 10.1021/ja0514545] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
N-Oxidation of hydroxyquinolines leads to a dramatic increase in their excited-state acidity. Time-resolved and steady-state emission characterization of 6-hydroxyquinoline-N-oxide and 2-methyl-6-hydroxyquinoline-N-oxide reveals a rich but less complex proton-transfer behavior than that of its parent hydroxyquinoline. The electronic effect of the oxidized heterocyclic nitrogen atom makes the excited state both less basic and more acidic than the parent and adds hydroxyquinoline N-oxides to the class of high-acidity excited-state proton donors in photochemistry and photobiology. Adiabatic photoinduced proton transfer is accompanied by the efficient nonreversible deoxygenation and 1-2 oxygen migration.
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Affiliation(s)
- Kyril M Solntsev
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA.
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25
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Mei N, Heflich RH, Chou MW, Chen T. Mutations induced by the carcinogenic pyrrolizidine alkaloid riddelliine in the liver cII gene of transgenic big blue rats. Chem Res Toxicol 2005; 17:814-8. [PMID: 15206902 PMCID: PMC6375673 DOI: 10.1021/tx049955b] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Riddelliine is a naturally occurring pyrrolizidine alkaloid that forms a number of different mononucleotide and dinucleotide adducts in DNA. It is a rodent carcinogen and a potential human hazard via food contamination. To examine the mutagenicity of riddelliine, groups of six female transgenic Big Blue rats were gavaged with 0.1, 0.3, and 1.0 mg riddelliine per kg body weight. The middle and high doses resulted in liver tumors in a previous carcinogenesis bioassay. The animals were treated 5 days a week for 12 weeks and sacrificed 1 day after the last treatment. The liver DNA was isolated for analysis of the mutant frequency (MF) in the transgenic cII gene, and the types of mutations were characterized by sequencing the mutants. A significant dose-dependent increase in MF was found, increasing from 30 x 10(-)(6) in the control animals to 47, 55, and 103 x 10(-)(6) in the low, middle, and high dose groups, respectively. Molecular analysis of the mutants indicated that there was a statistically significant difference between the mutational spectra from the riddelliine-treated and the control rats. A G:C --> T:A transversion (35%) was the major type of mutation in rats treated with riddelliine, whereas a G:C --> A:T transition (55%) was the predominant mutation in the controls. In addition, mutations from the riddelliine-treated rats included an unusually high frequency (8%) of tandem base substitutions of GG --> TT and GG --> AT. These results indicate that riddelliine is a genotoxic carcinogen in rat liver and that the types of mutations induced by riddelliine are consistent with riddelliine adducts involving G:C base pairs.
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Affiliation(s)
- Nan Mei
- Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas 72079, USA.
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26
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Fu PP, Xia Q, Lin G, Chou MW. Pyrrolizidine Alkaloids—Genotoxicity, Metabolism Enzymes, Metabolic Activation, and Mechanisms. Drug Metab Rev 2004; 36:1-55. [PMID: 15072438 DOI: 10.1081/dmr-120028426] [Citation(s) in RCA: 364] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Pyrrolizidine alkaloid-containing plants are widely distributed in the world and are probably the most common poisonous plants affecting livestock, wildlife, and humans. Because of their abundance and potent toxicities, the mechanisms by which pyrrolizidine alkaloids induce genotoxicities, particularly carcinogenicity, were extensively studied for several decades but not exclusively elucidated until recently. To date, the pyrrolizidine alkaloid-induced genotoxicities were revealed to be elicited by the hepatic metabolism of these naturally occurring toxins. In this review, we present updated information on the metabolism, metabolizing enzymes, and the mechanisms by which pyrrolizidine alkaloids exert genotoxicity and tumorigenicity.
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Affiliation(s)
- Peter P Fu
- National Center for Toxicological Research, Jefferson, Arkansas 72079, USA.
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27
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Chou MW, Wang YP, Yan J, Yang YC, Beger RD, Williams LD, Doerge DR, Fu PP. Riddelliine N-oxide is a phytochemical and mammalian metabolite with genotoxic activity that is comparable to the parent pyrrolizidine alkaloid riddelliine. Toxicol Lett 2004; 145:239-47. [PMID: 14580895 DOI: 10.1016/s0378-4274(03)00293-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pyrrolizidine alkaloids (PAs) and their N-oxide derivatives are naturally-formed genotoxic phytochemicals that are widely distributed throughout the world. Although, the quantities of PAs and PA N-oxides in plants are nearly equal, the biological and genotoxic activities of PA N-oxides have not been studied extensively. PA N-oxides are major metabolites of PAs and are generally regarded as detoxification products. However, in this study, we report that rat liver microsomes converted riddelliine N-oxide to the genotoxic 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP) metabolite. Metabolism of riddelliine N-oxide by rat liver microsomes under hypoxic conditions (argon) generated predominantly the parent PA, riddelliine. The reduction of riddelliine N-oxide to riddelliine was diminished, when the metabolism of riddelliine N-oxide with rat liver microsomes was conducted aerobically. Rat liver microsomal incubations of riddelliine N-oxide in the presence of calf thymus DNA produced a set of DHP-derived DNA adducts as detected and quantified by 32P-postlabeling/HPLC. The same DHP-derived DNA adducts were also found in liver DNA of F344 rats fed riddelliine N-oxide or riddelliine. When rats received doses of 1.0 mg/kg riddelliine N-oxide for three consecutive days, the level of DNA adducts was 39.9 +/- 0.6 adducts/10(7) nucleotides, which was 2.6-fold less than that measured in rats treated with riddelliine at the same dose. We have previously shown that these DHP-derived DNA adducts are produced by chronic feeding of riddelliine and that the adduct levels correlated with liver tumor formation. Results presented in this paper indicate that riddelliine N-oxide, through its conversion to riddelliine, is also a potential genotoxic hepatocarcinogen.
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Affiliation(s)
- Ming W Chou
- Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA.
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28
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Moyer C, Allen D, Basabe A, Maronpot RR, Nyska A. Analysis of Vascular Endothelial Growth Factor (VEGF) and a receptor subtype (KDR/flk-1) in the liver of rats exposed to riddelliine: a potential role in the development of hemangiosarcoma. ACTA ACUST UNITED AC 2004; 55:455-65. [PMID: 15384251 DOI: 10.1078/0940-2993-00344] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Riddelliine alters hepatocellular and endothelial cell kinetics and function including stimulating an increase in hepatocytic vascular endothelial growth factor (VEGF) in the absence of increased serological levels of VEGF (NYSKA et al. 2002). The objective of this study was to further assess hepatic VEGF and KDR/flk-1 synthesis and expression by hepatic cells under riddelliine treatment conditions. Forty-two male F344/N rats were dosed by gavage with riddelliine (0, 1.0, and 2.5 mg/kg/day) for 6 weeks. Seven animals/group were sacrificed after 8 consecutive daily doses; remaining rats were terminated after 30 daily doses, excluding weekends. Hepatic tissues were evaluated by immunohistochemistry and in situ hybridization. The results showed that VEGF mRNA expression was observed in control and treated animals; however, qualitative differences were noted. Treated animals exhibited VEGF mRNA in clustered, focal hepatocytes and bile duct epithelium, whereas VEGF mRNA in hepatocytes from vehicle control rats was distributed evenly across all hepatocytes. Results evaluating the distribution of the VEGF cognate receptor, KDR/flk-1 showed that randomly distributed, rare sinusoidal endothelium, including those demonstrating karyomegaly and cytomegaly expressed KDR/flk-1. Phosphorylation of KDR/flk-1 at pTyr996 and pTyr1054/1059, but not pTyr951, was also detected, evidence that endothelial cell KDR/flk-1 was activated. These results suggest that both hepatocytes and endothelial cells are targets of riddelliine-induced injury. We speculate that damage to both populations of cells may lead to dysregulated VEGF synthesis by hepatocytes and activation of KDR/flk-1 by endothelium leading to the induction of sustained endothelial cell proliferation, culminating in the development of hepatic hemangiosarcoma.
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MESH Headings
- Administration, Oral
- Animals
- Bile Ducts, Intrahepatic/drug effects
- Bile Ducts, Intrahepatic/metabolism
- Bile Ducts, Intrahepatic/pathology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/pathology
- Epithelial Cells/drug effects
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Hemangiosarcoma/etiology
- Hemangiosarcoma/pathology
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Hepatocytes/pathology
- Immunoenzyme Techniques
- In Situ Hybridization
- Liver/drug effects
- Liver/metabolism
- Liver Neoplasms/etiology
- Liver Neoplasms/pathology
- Male
- Pyrrolizidine Alkaloids/administration & dosage
- Pyrrolizidine Alkaloids/toxicity
- RNA Probes/chemistry
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred F344
- Vascular Endothelial Growth Factor A/biosynthesis
- Vascular Endothelial Growth Factor A/genetics
- Vascular Endothelial Growth Factor Receptor-2/biosynthesis
- Vascular Endothelial Growth Factor Receptor-2/genetics
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Affiliation(s)
- C Moyer
- Pathology Associates--A Charles River Company, Raleigh, North Carolina, USA
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29
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Hong HL, Ton TV, Devereux TR, Moomaw C, Clayton N, Chan P, Dunnick JK, Sills RC. Chemical-specific alterations in ras, p53, and beta-catenin genes in hemangiosarcomas from B6C3F1 mice exposed to o-nitrotoluene or riddelliine for 2 years. Toxicol Appl Pharmacol 2003; 191:227-34. [PMID: 13678655 DOI: 10.1016/s0041-008x(03)00165-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The most prominent neoplastic lesions in mice in the 2-year studies of o-nitrotoluene and riddelliine were hemangiosarcomas. Fifteen o-nitrotoluene-induced hemangiosarcomas of the skeletal muscle, subcutaneous tissue, and mesentery; 12 riddelliine-induced hemangiosarcomas of the liver; and 15 spontaneous subcutaneous hemangiosarcomas were examined for genetic alterations in ras, p53, and beta-catenin genes. Mutations in at least one of these genes were identified in 13 of 15 (87%) of the o-nitrotoluene-induced hemangiosarcomas with missense mutations in p53 exons 5-8 detected in 11 of 15 (73%) of these neoplasms. Seven of 15 (47%) hemangiosarcomas from mice exposed to o-nitrotoluene had deletions at exon 2 splice sites or smaller deletions in the beta-catenin gene. K-ras mutation was detected in only 1 of the 15 (7%) o-nitrotoluene-induced hemangiosarcomas. In contrast to the o-nitrotoluene study, 7/12 (58%) riddelliine-induced hemangiosarcomas had K-ras codon 12 GTT mutations and, when screened by immunohistochemistry, 9/12 (75%) had strong staining for the p53 protein in malignant endothelial cells, the cells of origin of hemangiosarcomas. Riddelliine-induced hemangiosarcomas were negative for the beta-catenin protein. Spontaneous hemangiosarcomas from control mice lacked both p53 and beta-catenin protein expression and ras mutations. Our data indicated that p53 and beta-catenin mutations in the o-nitrotoluene-induced hemangiosarcomas and K-ras mutations and p53 protein expression in riddelliine-induced hemangiosarcomas most likely occurred as a result of the genotoxic effects of these chemicals. It also suggests that these mutations play a role in the pathogenesis of the respective hemangiosarcomas in B6C3F1(1) mice.
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Affiliation(s)
- H L Hong
- Laboratory of Experimental Pathology, National Institute of Environmental Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709, USA.
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30
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Chou MW, Jian Y, Williams LD, Xia Q, Churchwell M, Doerge DR, Fu PP. Identification of DNA adducts derived from riddelliine, a carcinogenic pyrrolizidine alkaloid. Chem Res Toxicol 2003; 16:1130-7. [PMID: 12971801 DOI: 10.1021/tx030018y] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Riddelliine is a naturally occurring carcinogenic pyrrolizidine alkaloid that produces liver tumors in experimental animals. Riddelliine requires metabolic activation to dehydroriddelliine and 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP) to exert its toxicity. Previously, (32)P-postlabeling HPLC was used to detect a set of eight DHP-derived adduct peaks from DNA modified both in vitro and in vivo. Among these DHP-derived DNA adducts, two were identified as epimers of DHP-2'-deoxyguanosine 3'-monophosphate. In this study, the remaining adducts have been characterized as DHP-modified dinucleotides. A series of dinucleotides, TpGp, ApGp, TpCp, ApCp, TpAp, ApAp, TpTp, and ApTp, were obtained by enzymatic digestion of calf thymus DNA with micrococcal nuclease (MN) and spleen phosphodiesterase (SPD) followed by HPLC separation and structural identification by negative ion electrospray tandem mass spectrometry (ES/MS/MS). Incubation of individual dinucleotides with DHP produced DHP-modified dinucleotide adducts that were also characterized using LC-ES/MS/MS. A parallel analysis of the isolated DHP-modified dinucleotides using (32)P-postlabeling recapitulated the series of unidentified adduct peaks that we previously reported from DHP-modified calf thymus DNA in vitro and rat liver DNA in vivo. Intact calf thymus DNA was also reacted with DHP and then digested by MN/SPD under the same conditions. The adduct profile obtained from LC-ES/MS/MS analysis was similar to that observed from the isolated dinucleotides. Structural analysis using LC-ES/MS/MS showed that DHP bound covalently to both 3'- and 5'-guanine, -adenine, and -thymine bases (but not cytosine) of dinucleotides to produce two or more isomers of each DHP-dinucleotide adduct. By comparing adduct formation at dissimilar bases within individual dinucleotides, the relative reactivity of DHP with individual bases was determined to be guanine > adenine approximately thymine. Identification of the entire set of DHP-derived DNA adducts further validates the conclusion that riddelliine is a genotoxic carcinogen and enhances the applicability of these biomarkers for assessing carcinogenic risks from exposure to pyrrolizidine alkaloids.
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Affiliation(s)
- Ming W Chou
- National Center for Toxicological Research, Jefferson, Arkansas 72079, USA
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31
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Detection of Riddelliine-Derived DNA Adducts in Blood of Rats Fed Riddelliine. Int J Mol Sci 2002. [DOI: 10.3390/i3091019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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