1
|
Lis-Cieplak A, Trześniowska K, Stolarczyk K, Stolarczyk EU. Pyrrolizidine Alkaloids as Hazardous Toxins in Natural Products: Current Analytical Methods and Latest Legal Regulations. Molecules 2024; 29:3269. [PMID: 39064851 PMCID: PMC11279032 DOI: 10.3390/molecules29143269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 06/28/2024] [Accepted: 07/04/2024] [Indexed: 07/28/2024] Open
Abstract
Pyrrolizidine alkaloids (PAs) are toxic compounds that occur naturally in certain plants, however, there are many secondary pathways causing PA contamination of other plants, including medicinal herbs and plant-based food products, which pose a risk of human intoxication. It is proven that chronic exposure to PAs causes serious adverse health consequences resulting from their cytotoxicity and genotoxicity. This review briefly presents PA occurrence, structures, chemistry, and toxicity, as well as a set of analytical methods. Recently developed sensitive electrochemical and chromatographic methods for the determination of PAs in honey, teas, herbs, and spices were summarized. The main strategies for improving the analytical efficiency of PA determination are related to the use of mass spectrometric (MS) detection; therefore, this review focuses on advances in MS-based methods. Raising awareness of the potential health risks associated with the presence of PAs in food and herbal medicines requires ongoing research in this area, including the development of sensitive methods for PA determination and rigorous legal regulations of PA intake from herbal products. The maximum levels of PAs in certain products are regulated by the European Commission; however, the precise knowledge about which products contain trace but significant amounts of these alkaloids is still insufficient.
Collapse
Affiliation(s)
- Agnieszka Lis-Cieplak
- Spectrometric Methods Department, National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (A.L.-C.); (K.T.)
| | - Katarzyna Trześniowska
- Spectrometric Methods Department, National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (A.L.-C.); (K.T.)
| | | | - Elżbieta U. Stolarczyk
- Spectrometric Methods Department, National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; (A.L.-C.); (K.T.)
| |
Collapse
|
2
|
Zagorski JW, Kaminski NE. Utilization of a novel human hepatocyte-endothelial cell coculture model to determine differential toxicities of pyrrolizidine alkaloid food contaminants. Food Chem Toxicol 2024; 187:114584. [PMID: 38490353 DOI: 10.1016/j.fct.2024.114584] [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: 01/26/2024] [Revised: 03/04/2024] [Accepted: 03/07/2024] [Indexed: 03/17/2024]
Abstract
Pyrrolizidine alkaloids (PA) are comprised of a family of hundreds of metabolites, produced by plants as a mechanism to protect against herbivory. Upon ingestion and metabolism, dehydropyrrolizidine alkaloids are formed, which are known to generate DNA adducts and subsequently double-strand DNA breaks. Within the liver, the most sensitive cell type to PA exposure is the sinusoidal endothelial cell, as evidenced by the generation of veno-occlusive disease in the human population. PAs are a common crop contaminant and have been regulated by some agencies, using the precautionary principle; each equally potent and genotoxic. Therefore, as a proof of principle we have established a human in vitro coculture model system, utilizing the metabolically active HepaRG hepatocyte and the SK-Hep-1 endothelial cell, to determine differential potencies of different PAs commonly found in crops and food products, notably cell death, targeting of endothelial cells, and genotoxicity comparing the micronucleus assay versus γH2AX assay. Our results demonstrate differential potencies of the PAs used, which encompass three esterification states (monoester, cyclic diester, and open-chain diester). The results suggest that a more nuanced approach to the regulation of PAs may be more appropriate in the regulatory decision-making process.
Collapse
Affiliation(s)
- Joseph W Zagorski
- Center for Research on Ingredient Safety, Michigan State University, East Lansing, MI, 48824, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA
| | - Norbert E Kaminski
- Center for Research on Ingredient Safety, Michigan State University, East Lansing, MI, 48824, USA; Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, 48824, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA.
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Lu YS, Qiu J, Mu XY, Qian YZ, Chen L. Levels, Toxic Effects, and Risk Assessment of Pyrrolizidine Alkaloids in Foods: A Review. Foods 2024; 13:536. [PMID: 38397512 PMCID: PMC10888194 DOI: 10.3390/foods13040536] [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: 12/28/2023] [Revised: 01/30/2024] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
Pyrrolizidine alkaloids (PAs) are naturally occurring secondary metabolites of plants. To date, more than 660 types of PAs have been identified from an estimated 6000 plants, and approximately 120 of these PAs are hepatotoxic. As a result of PAs being found in spices, herbal teas, honey, and milk, PAs are considered contaminants in foods, posing a potential risk to human health. Here, we summarize the chemical structure, toxic effects, levels, and regulation of PAs in different countries to provide a better understanding of their toxicity and risk assessment. With recent research on the risk assessment of PAs, this review also discusses the challenges facing this field, aiming to provide a scientific basis for PA toxicity research and safety assessment.
Collapse
Affiliation(s)
- Yu-Shun Lu
- Key Laboratory of Agro-Product Quality and Safety, Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.-S.L.); (Y.-Z.Q.)
- Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun 130112, China
| | - Jing Qiu
- Key Laboratory of Agro-Product Quality and Safety, Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.-S.L.); (Y.-Z.Q.)
| | - Xi-Yan Mu
- Key Laboratory of Agro-Product Quality and Safety, Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.-S.L.); (Y.-Z.Q.)
| | - Yong-Zhong Qian
- Key Laboratory of Agro-Product Quality and Safety, Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.-S.L.); (Y.-Z.Q.)
| | - Lu Chen
- Key Laboratory of Agro-Product Quality and Safety, Institute of Quality Standards and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.-S.L.); (Y.-Z.Q.)
| |
Collapse
|
5
|
Akuamoa F, Mulder PPJ, Bovee TFH, Rietjens IMCM, Hoogenboom RLAP. Occurrence and associated health risks of pyrrolizidine alkaloids in supplements marketed in Ghana for improved sexual performance. FOOD ADDITIVES & CONTAMINANTS. PART B, SURVEILLANCE 2023; 16:301-309. [PMID: 37448098 DOI: 10.1080/19393210.2023.2227961] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 06/18/2023] [Indexed: 07/15/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are noted for their hepatotoxic, genotoxic, and carcinogenic effects in animals and humans following metabolic activation in the liver. In this study, herbal supplements sold in Ghana for sexual improvement were analysed for the presence of 64 PAs using LC-MS/MS analysis. Up to 17 different PAs were identified in 19 out of the 37 samples analysed. The sum of PAs in samples ranged from 5 to 3204 μg kg-1. Since the PA content in the herbal medicinal preparations was generally lower than in honey samples, their presence was mainly attributed to cross-contamination. The observed levels would result in estimated daily intakes from 0.01 to 12 μg per day or 0.0002 to 0.2 μg kg-1 bw day-1 for a person weighing 70 kg. The margins of exposure ranged from 1200 to 1,400,000 with eight samples showing values below 10,000, thus indicating a health concern.
Collapse
Affiliation(s)
- Felicia Akuamoa
- Wageningen Food Safety Research, Wageningen, The Netherlands
- Division of Toxicology, Wageningen University and Research, Wageningen, The Netherlands
- Applied Radiation Biology Centre, Ghana Atomic Energy Commission, Accra, Ghana
| | | | - Toine F H Bovee
- Wageningen Food Safety Research, Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, Wageningen, The Netherlands
| | | |
Collapse
|
6
|
Pan Y, Ma J, Zhao H, Fu PP, Lin G. Hepatotoxicity screening and ranking of structurally different pyrrolizidine alkaloids in zebrafish. Food Chem Toxicol 2023:113903. [PMID: 37390955 DOI: 10.1016/j.fct.2023.113903] [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: 01/13/2023] [Revised: 06/09/2023] [Accepted: 06/15/2023] [Indexed: 07/02/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are phytotoxins distributed in ∼6000 plant species. PA-contaminated/containing foodstuffs/herbs/supplements pose a potential threat to human health. Various regulatory authorities established different PA margins of exposure assuming an equal hepatotoxic potency of structurally diverse PAs, although they exhibit different toxic potencies. Therefore, understanding hepatotoxic potencies of different PAs would facilitate a more appropriate risk assessment of PA exposure. In this study, a zebrafish model, which mimics physiological processes of absorption, distribution, metabolism, and excretion, was selected to evaluate acute hepatotoxic potency of different PAs (7 PAs and 2 PA N-oxides) and explore possible physiological pathways involved in PA-induced hepatotoxicity. After 6 h oral administration, PAs caused distinct structure-dependent hepatotoxicity with a series of biochemical and histological changes in zebrafish. Based on the measured toxicological endpoints, the relative toxic potency order of different PAs was derived as lasiocarpine ∼ retrorsine > monocrotaline > riddelliine > clivorine > heliotrine > retrorsine N-oxide ∼ riddelliine N-oxide≫>platyphyline. Further, compared to control group, different upregulation/downregulation of mRNA expression in PA-treated groups indicated that inflammation, apoptosis, and steatosis were involved in PA-induced hepatotoxicity in zebrafish. These findings demonstrate that zebrafish model is useful for screening and ranking hepatotoxicity of PAs with diverse structures, which would facilitate the more accurate risk assessment of PA exposure.
Collapse
Affiliation(s)
- Yueyang Pan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
| | - Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; School of Chinese Materia Medica, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Hui Zhao
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | - Peter P Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.
| |
Collapse
|
7
|
Widjaja F, Alhejji Y, Yangchen J, Wesseling S, Rietjens IMCM. Physiologically-Based Kinetic Modeling Predicts Similar In Vivo Relative Potency of Senecionine N-Oxide for Rat and Human at Realistic Low Exposure Levels. Mol Nutr Food Res 2023; 67:e2200293. [PMID: 36478522 DOI: 10.1002/mnfr.202200293] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 10/30/2022] [Indexed: 12/12/2022]
Abstract
SCOPE This study aims to determine if previously developed physiologically-based kinetic (PBK) model in rat can be modified for senecionine (SEN) and its N-oxide (SENO), and be used to investigate potential species differences between rat and human in relative potency (REP) of the N-oxide relative to the parent pyrrolizidine alkaloid (PA). METHODS AND RESULTS In vitro derived kinetic parameters including the apparent maximum velocities (Vmax ) and Michaelis-Menten constants (Km ) for SENO reduction and SEN clearance are used to define the PBK models. The rat model is validated with published animal data, and the toxicokinetic profiles of SEN from either orally-administered SENO or SEN are simulated. REP values of SENO relative to SEN amount to 0.84 and 0.89 in rat and human, respectively. CONCLUSION The REP value can be dose- and species-dependent, with the values for rat and human being comparable at low realistic exposure scenarios. In summary, PBK modeling serves as a valuable New Approach Methodology (NAM) tool for predicting REP values of PA-N-oxides and may actually result in more accurate REP values for human risk assessment than what would be defined using in vivo animal experiments.
Collapse
Affiliation(s)
- Frances Widjaja
- Division of Toxicology, Wageningen University, PO Box 8000, Wageningen, 6700 EA, The Netherlands
| | - Yasser Alhejji
- Division of Toxicology, Wageningen University, PO Box 8000, Wageningen, 6700 EA, The Netherlands.,Department of Food Science and Human Nutrition, College of Agriculture and Veterinary Medicine, Qassim University, Buraydah, 51452, Saudi Arabia
| | - Jamyang Yangchen
- Division of Toxicology, Wageningen University, PO Box 8000, Wageningen, 6700 EA, The Netherlands.,Bhutan Agriculture and Food Regulatory Authority, Ministry of Agriculture and Forests, Thimphu, 11002, Bhutan
| | - Sebastiaan Wesseling
- Division of Toxicology, Wageningen University, PO Box 8000, Wageningen, 6700 EA, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, PO Box 8000, Wageningen, 6700 EA, The Netherlands
| |
Collapse
|
8
|
Risk Assessment of (Herbal) Teas Containing Pyrrolizidine Alkaloids (PAs) Based on Margin of Exposure Approach and Relative Potency (REP) Factors. Foods 2022; 11:foods11192946. [PMID: 36230022 PMCID: PMC9564199 DOI: 10.3390/foods11192946] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/13/2022] [Accepted: 09/15/2022] [Indexed: 12/03/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) present distinct toxicity potencies depending on their metabolites and in vivo toxicokinetics. To represent the potency differences of various PAs, the interim relative potency (REP) factors have been derived. However, little is known about the risk assessment for (herbal) teas when taking REP factors into account. In this study, a set of 68 individual 1,2-unsaturated PA in 21 types of (herbal) teas was analyzed using LC-MS/MS. The REP factors for these PAs were applied on the PA levels. The margin of exposure (MOE) approach was employed to assess the risks of the exposure to PAs due to consumption of (herbal) teas. The results show that the total PA levels ranged from 13.4 to 286,682.2 μg/kg d.m., which were decreased by REP correction in most of the teas. The MOE values for tephroseris, borage and lemon balm (melissa) tea based on REP-corrected PA levels were below 10,000, assuming daily consumption of one cup of tea during a lifetime, indicating that consuming these teas may raise a concern. Our study also indicates a priority for risk management for tephroseris tea, as having nephrosis tea for more than 11.2 weeks during a 75-year lifetime would result in an MOE of 10,000.
Collapse
|
9
|
Combined Hepatotoxicity and Toxicity Mechanism of Intermedine and Lycopsamine. Toxins (Basel) 2022; 14:toxins14090633. [PMID: 36136571 PMCID: PMC9501075 DOI: 10.3390/toxins14090633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/17/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) are common constituents of plants and have serious hepatotoxicity. Intermedine (Im) and lycopsamine (La) are two monoesters of PAs that frequently coexist in the PA-containing plants (e.g., comfrey and tea). The present study aimed to explore the combined hepatotoxicity and toxicity mechanism of the Im and La mixture. In vitro, the combined cytotoxicity of the Im and La mixture on human hepatocytes (HepD) was examined by CCK-8, colony formation, wound healing, and Annexin V/PI staining assays. The combination of Im and La inhibited the ability of HepD cells to proliferate, colonize, and migrate and induced hepatocytes apoptosis in a dose-dependent manner. In addition to significantly causing a burst of intracellular reactive oxygen species (ROS), mitochondrial apoptosis, and endoplasmic reticulum (ER) stress, the Im and La mixture can also cause an increase in intracellular Ca2+, triggering the PERK/eIF2α/ATF4/CHOP apoptosis pathway. This study provided the first direct evidence that the combined PAs induced hepatotoxicity through ER-mediated apoptosis. These results supplemented the basic toxicity data for the combined PAs and provided a new perspective for the risk assessment of combined PA toxicity.
Collapse
|
10
|
Isolation of Echimidine and Its C-7 Isomers from Echium plantagineum L. and Their Hepatotoxic Effect on Rat Hepatocytes. Molecules 2022; 27:molecules27092869. [PMID: 35566223 PMCID: PMC9102911 DOI: 10.3390/molecules27092869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 12/10/2022] Open
Abstract
Echimidine is the main pyrrolizidine alkaloid of Echium plantagineum L., a plant domesticated in many countries. Because of echimidine’s toxicity, this alkaloid has become a target of the European Food Safety Authority regulations, especially in regard to honey contamination. In this study, we determined by NMR spectroscopy that the main HPLC peak purified from zinc reduced plant extract with an MS [M + H]+ signal at m/z 398 corresponding to echimidine (1), and in fact also represents an isomeric echihumiline (2). A third isomer present in the smallest amount and barely resolved by HPLC from co-eluting (1) and (2) was identified as hydroxymyoscorpine (3). Before the zinc reduction, alkaloids (1) and (2) were present mostly (90%) in the form of an N-oxide, which formed a single peak in HPLC. This is the first report of finding echihumiline and hydroxymyoscorpine in E. plantagineum. Retroanalysis of our samples of E. plantagineum collected in New Zealand, Argentina and the USA confirmed similar co-occurrence of the three isomeric alkaloids. In rat hepatocyte primary culture cells, the alkaloids at 3 to 300 µg/mL caused concentration-dependent inhibition of hepatocyte viability with mean IC50 values ranging from 9.26 to 14.14 µg/mL. Our discovery revealed that under standard HPLC acidic conditions, echimidine co-elutes with its isomers, echihumiline and to a lesser degree with hydroxymyoscorpine, obscuring real alkaloidal composition, which may have implications for human toxicity.
Collapse
|
11
|
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] [Grants] [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.
Collapse
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
| | | |
Collapse
|
12
|
Hepatotoxicity of Pyrrolizidine Alkaloid Compound Intermedine: Comparison with Other Pyrrolizidine Alkaloids and Its Toxicological Mechanism. Toxins (Basel) 2021; 13:toxins13120849. [PMID: 34941687 PMCID: PMC8709407 DOI: 10.3390/toxins13120849] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/18/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) are common secondary plant compounds with hepatotoxicity. The consumption of herbal medicines and herbal teas containing PAs is one of the main causes of hepatic sinusoidal obstruction syndrome (HSOS), a potentially life-threatening condition. The present study aimed to reveal the mechanism underlying the cytotoxicity of intermedine (Im), the main PA in Comfrey. We evaluated the toxicity of the retronecine-type PAs with different structures to cell lines derived from mammalian tissues, including primary mouse hepatocytes, human hepatocytes (HepD), mouse hepatoma-22 (H22) and human hepatocellular carcinoma (HepG2) cells. The cytotoxicity of Im to hepatocyte was evaluated by using cell counting kit-8 assay, colony formation experiment, wound healing assay and dead/live fluorescence imaging. In vitro characterization showed that these PAs were cytotoxic and induced cell apoptosis in a dose-dependent manner. We also demonstrated that Im induced cell apoptosis by generating excessive reactive oxygen species (ROS), changing the mitochondrial membrane potential and releasing cytochrome c (Cyt c) before activating the caspase-3 pathway. Importantly, we directly observed the destruction of the cell mitochondrial structure after Im treatment through transmission electron microscopy (TEM). This study provided the first direct evidence of Im inducing hepatotoxicity through mitochondria-mediated apoptosis. These results supplemented the basic toxicity data of PAs and facilitated the comprehensive and systematic evaluation of the toxicity caused by PA compounds.
Collapse
|
13
|
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.
Collapse
|
14
|
Mrkajic NS, Hama JR, Strobel BW, Hansen HCB, Rasmussen LH, Pedersen AK, Christensen SCB, Hedegaard MJ. Removal of phytotoxins in filter sand used for drinking water treatment. WATER RESEARCH 2021; 205:117610. [PMID: 34649082 PMCID: PMC8556162 DOI: 10.1016/j.watres.2021.117610] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 06/06/2023]
Abstract
Phytotoxins - toxins produced by plants - are contaminants with the potential to impair drinking water quality. They encompass a large group of toxic, partially persistent compounds that have been detected in seepage waters and in shallow wells used for drinking water production. If phytotoxins enter wells used for drinking water production, it is essential to know if the drinking water treatment processes will remove them from the water phase. However, it is currently unknown whether phytotoxins remain stable during traditional groundwater treatment using sand filters as the main treatment process. The objective of this study is to investigate removal potential of phytotoxins in biological sand filters and to asses if the removal potential is similar at different waterworks. Microcosms were set up with filter sand and drinking water collected at different groundwater-based waterworks. To be able to monitor phytotoxin removal ptaquiloside, caudatoside, gramine, sparteine, jacobine N-oxide, senecionine N-oxide and caffeine were applied at initial concentrations of 300 µg L-1, which is approx. two orders of magnitude higher than currently detected in environment, but expected to cover extreme environmental conditions. Removal was monitored over a period of 14 days. Despite the high initial concentration, all filter sands removed ptaquiloside and caudatoside completely from the water phase and at waterworks where pellet softening was implemented (pH 8.4) prior to rapid sand filtration, complete removal occurred within the first 30 min. All filter sands removed gramine and sparteine, primarily by a biological process, while jacobine N-oxide, senecionine N-oxide and caffeine were recalcitrant in the filter sands. During degradation of ptaquiloside and caudatoside we observed formation and subsequent removal of degradation products pterosin B and A. Filter sands with the highest removal potential were characterised by high contents of deposited iron and manganese oxides and hence large specific surface areas. Difference between bacterial communities investigated by 16S rRNA gene analyses did not explain different removal in the filter sands. All five investigated filter sands showed similar degradation patterns regardless of water chemistry and waterworks of origin. In drinking water treatment systems biological sand filters might therefore remove phytotoxin contaminants such as ptaquiloside, caudatoside, gramine, sparteine, while for other compounds e.g. jacobine N-oxide, senecionine N-oxide further investigations involving more advanced treatment options are needed.
Collapse
Affiliation(s)
- Natasa Skrbic Mrkajic
- Greater Copenhagen Utility HOFOR, Parkstien 10, 2450, Copenhagen, Denmark; Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Jawameer R Hama
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Bjarne W Strobel
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Hans Chr B Hansen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark
| | - Lars Holm Rasmussen
- Department of Technology, University College Copenhagen, Sigurdsgade 26, 2200 Copenhagen, Denmark
| | | | | | | |
Collapse
|
15
|
He X, Xia Q, Shi Q, Fu PP. Metabolism of carcinogenic pyrrolizidine alkaloids and pyrrolizidine alkaloid N-oxides by rat primary hepatocytes generate the same characteristic DHP-DNA adducts. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, TOXICOLOGY AND CARCINOGENESIS 2021; 39:357-372. [PMID: 35895950 DOI: 10.1080/26896583.2021.1954460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We recently established a genotoxic mechanism mediated by a set of (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-DNA adducts, which lead to pyrrolizidine alkaloid (PA)-induced liver tumor initiation. This mechanism is involved in the metabolism of a series of carcinogenic PAs and PA N-oxides in rats in vivo and in vitro. There is a correlation between the order of liver tumor potency and the level of DHP-DNA adduct formation. Thus, these DHP-DNA adducts can be potential biomarkers of PA and PA N-oxide exposure and liver tumor initiation. To establish the generality of this mechanism, in the present study, we examined the metabolism of 13 potential carcinogenic PAs, 1 non-carcinogenic PA, and 5 PA N-oxides by male rat primary hepatocytes. With the exception of the nontoxic PA and vehicle control, all treated groups produced identical set of DHP-DNA adducts. These results support a general genotoxic mechanism mediated by the formation of characteristic DHP-DNA adducts leading to PA-induced liver tumor initiation.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research, Jefferson, AR, USA
| | - Qingsu Xia
- National Center for Toxicological Research, Jefferson, AR, USA
| | - Qiang Shi
- National Center for Toxicological Research, Jefferson, AR, USA
| | - Peter P Fu
- National Center for Toxicological Research, Jefferson, AR, USA
| |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
Long F, Ji J, Wang X, Wang L, Chen T. LC-MS/MS method for determination of seneciphylline and its metabolite, seneciphylline N-oxide in rat plasma, and its application to a rat pharmacokinetic study. Biomed Chromatogr 2021; 35:e5145. [PMID: 33886121 DOI: 10.1002/bmc.5145] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/02/2021] [Accepted: 04/19/2021] [Indexed: 01/16/2023]
Abstract
A rapid and sensitive ultra-performance liquid chromatography-tandem electrospray ionization mass spectrometry (UPLC-ESI/MS) method was established and validated for simultaneous determination of seneciphylline and its main metabolite in rat plasma. The plasma sample was prepared by simple methanol-mediated precipitation. Chromatographic separation was achieved within 3 min by gradient elution using acetonitrile and water containing 0.1% formic acid as mobile phase on a Waters ACQUITY BEH C18 column (100 × 2.1 mm, i.d. 1.7 μm). Quantitation was conducted in a positive multiple reaction monitoring mode. The linearity of the method was over the range of 1-1,000 ng/mL, with the lower limit of quantification of 1 ng/mL. The intra- and inter-day precision and accuracy, extraction recovery, and matrix effect of analytes were within the acceptable limit. The analytes were stable during the process of sample collection, preparation, and analysis. The validated method was further applied to a pharmacokinetic study of seneciphylline in rats after oral and intravenous administration. The results revealed that seneciphylline was quickly absorbed into plasma (Tmax , 0.23-0.32 h) and reached the maximum concentration of 0.82-1.75 μg/mL after oral administration. Both seneciphylline and seneciphylline N-oxide were eliminated from plasma quickly. The low system exposure (oral bioavailability, 5.43-10.31%) was related to the extensive metabolism in the liver and microflora.
Collapse
Affiliation(s)
- Feng Long
- Department of Pharmacy, Maternal and Child Health Care Hospital of Zaozhuang, Zaozhuang, China
| | - Jie Ji
- Department of Pharmacy, Maternal and Child Health Center of Dezhou, Dezhou, China
| | - Xin Wang
- Department of Pharmacy, Maternal and Child Health Care Hospital of Zaozhuang, Zaozhuang, China
| | - Lili Wang
- Department of Pharmacy, Maternal and Child Health Care Hospital of Zaozhuang, Zaozhuang, China
| | - Ting Chen
- Department of Pharmacy, Maternal and Child Health Care Hospital of Zaozhuang, Zaozhuang, China
| |
Collapse
|
18
|
Kisielius V, Hama JR, Skrbic N, Hansen HCB, Strobel BW, Rasmussen LH. The invasive butterbur contaminates stream and seepage water in groundwater wells with toxic pyrrolizidine alkaloids. Sci Rep 2020; 10:19784. [PMID: 33188248 PMCID: PMC7666219 DOI: 10.1038/s41598-020-76586-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 10/30/2020] [Indexed: 12/21/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) are persistent mutagenic and carcinogenic compounds produced by many common plant species. Health authorities recommend minimising human exposure via food and medicinal products to ensure consumer health and safety. However, there is little awareness that PAs can contaminate water resources. Therefore, no regulations exist to limit PAs in drinking water. This study measured a PA base concentration of ~ 70 ng/L in stream water adjacent to an invasive PA-producing plant Petasites hybridus (Asteraceae). After intense rain the PA concentration increased tenfold. In addition, PAs measured up to 230 ng/L in seepage water from groundwater wells. The dominant PAs in both water types corresponded to the most abundant PAs in the plants (senkirkine, senecionine, senecionine N-oxide). The study presents the first discovery of persistent plant toxins in well water and their associated risks. In addition, it for the first time reports monocrotaline and monocrotaline N-oxide in Petasites sp.
Collapse
Affiliation(s)
- Vaidotas Kisielius
- Department of Technology, University College Copenhagen, Sigurdsgade 26, 2200, Copenhagen, Denmark.
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark.
| | - Jawameer R Hama
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Natasa Skrbic
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
- Greater Copenhagen Utility HOFOR, Ørestads Blvd. 35, 2300, Copenhagen, Denmark
| | - Hans Christian Bruun Hansen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Bjarne W Strobel
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Lars Holm Rasmussen
- Department of Technology, University College Copenhagen, Sigurdsgade 26, 2200, Copenhagen, Denmark
| |
Collapse
|
19
|
Xiong F, Jiang K, Chen Y, Ju Z, Yang L, Xiong A, Wang Z. Protein cross-linking in primary cultured mouse hepatocytes by dehydropyrrolizidine alkaloids: Structure-toxicity relationship. Toxicon 2020; 186:4-11. [PMID: 32687888 DOI: 10.1016/j.toxicon.2020.07.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/13/2020] [Accepted: 07/15/2020] [Indexed: 02/07/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are natural toxins found in about 3%-5% of flowering plants. Dehydropyrrolizidine alkaloids contain a double bond in 1, 2-position of the necine bases, including retronecine type PAs (RET-PAs) and their N-oxides (RET N-oxide-PAs), and otonecine type PAs (OTO-PAs), and are known for their significant hepatotoxicity. Most dehydropyrrolizidine alkaloids are metabolically activated by cytochrome P450 (CYP450) enzymes to generate active pyrroles, which further bind to proteins to form pyrrole-protein adducts (PPAs). Methods for predicting PA-induced liver injury are generally performed on in vitro models with extremely low activities of CYP450 enzymes, which is different from the situation in vivo. In this regard, primary cultured mouse hepatocytes, which showed comparable CYP450 activity with the in vivo models, were applied to illustrate the structure-toxicity relationship of 13 dehydropyrrolizidine alkaloids, namely, eight RET-PAs, three RET N-oxide-PAs, and two OTO-PAs. PA-induced cytotoxicity and PA-generated PPAs were analyzed in primary mouse hepatocytes treated with different PAs. Results showed that PA-induced toxicity was correlated with the amount of PA-generated PPAs. RET-PAs and OTO-PAs were generally more toxic than RET N-oxide-PAs and generated higher amount of PPAs. PPAs were utilized to evaluate the efficiency of metabolic activation and predict the toxic potencies of dehydropyrrolizidine alkaloids. The proposed model could be a new approach for toxicity evaluation and risk control of exposure to PAs.
Collapse
Affiliation(s)
- Fen Xiong
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Kaiyuan Jiang
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Yan Chen
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Zhengcai Ju
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China
| | - Li Yang
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China; Shanghai R & D Center for Standardization of Traditional Chinese Medicines, Shanghai, 201203, China.
| | - Aizhen Xiong
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China; Shanghai R & D Center for Standardization of Traditional Chinese Medicines, Shanghai, 201203, China.
| | - Zhengtao Wang
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, China; Shanghai R & D Center for Standardization of Traditional Chinese Medicines, Shanghai, 201203, China
| |
Collapse
|
20
|
Wang W, Yang X, Chen Y, Ye X, Jiang K, Xiong A, Yang L, Wang Z. Seneciphylline, a main pyrrolizidine alkaloid in Gynura japonica, induces hepatotoxicity in mice and primary hepatocytes via activating mitochondria-mediated apoptosis. J Appl Toxicol 2020; 40:1534-1544. [PMID: 32618019 DOI: 10.1002/jat.4004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/28/2020] [Accepted: 05/13/2020] [Indexed: 01/07/2023]
Abstract
Herbal drug-induced liver injury has been reported worldwide and gained global attention. Thousands of hepatic sinusoidal obstruction syndrome (HSOS) cases have been reported after consumption of herbal medicines and preparations containing pyrrolizidine alkaloids (PAs), which are natural phytotoxins globally distributed. And herbal medicines, such as Gynura japonica, are the current leading cause of PA-induced HSOS. The present study aimed to reveal the mechanism underlying the hepatotoxicity of seneciphylline (Seph), a main PA in G. japonica. Results showed that Seph induced severe liver injury through apoptosis in mice (70 mg/kg Seph, orally) and primary mouse and human hepatocytes (5-50 μM Seph). Further research uncovered that Seph induced apoptosis by disrupting mitochondrial homeostasis, inducing mitochondrial depolarization, mitochondrial membrane potential (MMP) loss, and cytochrome c (Cyt c) release and activating c-Jun N-terminal kinase (JNK). The Seph-induced apoptosis in hepatocytes could be alleviated by Mdivi-1 (50 μM, a dynamin-related protein 1 inhibitor), as well as SP600125 (25 μM, a specific JNK inhibitor) and ZVAD-fmk (50 μM, a general caspase inhibitor). Moreover, the Seph-induced MMP loss in hepatocytes was also rescued by Mdivi-1. In conclusion, Seph induced liver toxicity via activating mitochondrial-mediated apoptosis in mice and primary hepatocytes. Our results provide further information on Seph detoxification and herbal medicines containing Seph such as G. japonica.
Collapse
Affiliation(s)
- Weiqian Wang
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiao Yang
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yan Chen
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xuanling Ye
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Kaiyuan Jiang
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Aizhen Xiong
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Li Yang
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zhengtao Wang
- The MOE Key Laboratory for Standardization of Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| |
Collapse
|
21
|
Yang M, Ma J, Ruan J, Zhang C, Ye Y, Pi-Cheng Fu P, Lin G. Absorption difference between hepatotoxic pyrrolizidine alkaloids and their N-oxides - Mechanism and its potential toxic impact. JOURNAL OF ETHNOPHARMACOLOGY 2020; 249:112421. [PMID: 31759111 DOI: 10.1016/j.jep.2019.112421] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/22/2019] [Accepted: 11/19/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Pyrrolizidine alkaloids (PAs) are a group of phytotoxins widely present in about 3% of flowering plants. Many PA-containing herbal plants can cause liver injury. Our previous studies demonstrated that PA N-oxides are also hepatotoxic, with toxic potency much lower than the corresponding PAs, due to significant differences in their toxicokinetic fates. AIM OF STUDY This study aimed to investigate the oral absorption of PAs and PA N-oxides for better understanding of their significant differences in toxicokinetics and toxic potency. MATERIALS AND METHODS The oral absorption of PAs and PA N-oxides in rats and in rat in situ single pass intestine perfusion model was investigated. The intestinal permeability and absorption mechanisms of five pairs of PAs and PA N-oxides were evaluated by using Caco-2 monolayer model. RESULTS The plasma concentrations of total PAs and PA N-oxides within 0-60 min were significantly lower in rats orally treated with a PA N-oxide-containing herbal alkaloid extract than with a PA-containing herbal alkaloid extract at the same dose, indicating that the absorption of PA N-oxides was lower than that of PAs. Using the rat in situ single pass intestine perfusion model, less cumulative amounts of retrorsine N-oxide in mesenteric blood were observed compared to that of retrorsine. In Caco-2 monolayer model, all five PAs showed absorption with Papp AtoB values [(1.43-16.26) × 10-6 cm/s] higher than those of corresponding N-oxides with Papp AtoB values lower than 1.35 × 10-6 cm/s. A further mechanistic study demonstrated that except for senecionine N-oxide, retrorsine N-oxide, and lycopsamine N-oxide, all PAs and PA N-oxides investigated were absorbed via passive diffusion. While, for these 3 PA N-oxides, in addition to passive diffusion as their primary transportation, efflux transporter-mediated active transportation was also involved but to a less extent with the efflux ratio of 2.31-3.41. Furthermore, a good correlation between lipophilicity and permeability of retronecine-type PAs and their N-oxides with absorption via passive diffusion was observed, demonstrating that PAs have a better oral absorbability than that of the corresponding PA N-oxides. CONCLUSION We discovered that among many contributors, the lower intestinal absorption of PA N-oxides was the initiating contributor that caused differences in toxicokinetics and toxic potency between PAs and PA N-oxides.
Collapse
Affiliation(s)
- Mengbi Yang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines between the Chinese University of Hong Kong and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China
| | - Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines between the Chinese University of Hong Kong and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China
| | - Jianqing Ruan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines between the Chinese University of Hong Kong and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China
| | - Chunyuan Zhang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines between the Chinese University of Hong Kong and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China
| | - Yang Ye
- Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines between the Chinese University of Hong Kong and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China
| | - Peter Pi-Cheng Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, USA
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong; Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines between the Chinese University of Hong Kong and Shanghai Institute of Materia Medica, Chinese Academy of Sciences, China.
| |
Collapse
|
22
|
Suparmi S, Mulder PPJ, Rietjens IMCM. Detection of pyrrolizidine alkaloids in jamu available on the Indonesian market and accompanying safety assessment for human consumption. Food Chem Toxicol 2020; 138:111230. [PMID: 32113951 DOI: 10.1016/j.fct.2020.111230] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 02/22/2020] [Accepted: 02/24/2020] [Indexed: 12/26/2022]
Abstract
The occurrence and accompanying risks of pyrrolizidine alkaloids (PAs) in Indonesian jamu were evaluated. PAs were detected in 34 out of 35 jamu containing PA-producing botanicals, in the range of 12.3-235,376 μg/kg. A total PA level of 5.9-3,421 μg/kg was found in 17 out of 23 jamu made of non-PA-producing botanicals pointing to contamination with PA-producing plants. Short-time consumption of jamu is unlikely to result in acute toxic effects, although one sample would exceed an intake of 10 μg PA/kg bw/day which may cause hepatic veno-occlusive disease (HVOD) in humans. The risk assessment for the genotoxic and carcinogenic potential of PAs revealed Margin of Exposure (MOE) values below 10,000 for 27 out of all samples analysed (46.6%), indicating a priority for risk management when assuming daily lifelong consumption. Assuming consumption for two weeks every year during a lifetime, and using Haber's rule, 13 out of 35 jamu samples containing PA-producing botanicals (37%) still pose a priority, while the jamu consisting of non-PA-producing botanicals would be of low priority (MOE>10,000). This study provides data that can support risk management actions in Indonesia to minimize the potential health risk for jamu consumers due to the occurrence of toxic PAs in these products.
Collapse
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.
| | - Patrick P J Mulder
- Wageningen Food Safety Research, Akkermaalsbos 2, 6708 WB, Wageningen, the Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University and Research, Stippeneng 4, 6708 WE, Wageningen, the Netherlands
| |
Collapse
|
23
|
Xu J, Wang W, Yang X, Xiong A, Yang L, Wang Z. Pyrrolizidine alkaloids: An update on their metabolism and hepatotoxicity mechanism. LIVER RESEARCH 2019. [DOI: 10.1016/j.livres.2019.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
|
24
|
Prediction of in vivo genotoxicity of lasiocarpine and riddelliine in rat liver using a combined in vitro-physiologically based kinetic modelling-facilitated reverse dosimetry approach. Arch Toxicol 2019; 93:2385-2395. [PMID: 31289892 DOI: 10.1007/s00204-019-02515-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 07/04/2019] [Indexed: 12/16/2022]
Abstract
Pyrrolizidine alkaloids (PAs) are naturally occurring genotoxic compounds, and PA-containing plants can pose a risk to humans through contaminated food sources and herbal products. Upon metabolic activation, PAs can form DNA adducts, DNA and protein cross links, chromosomal aberrations, micronuclei, and DNA double-strand breaks. These genotoxic effects may induce gene mutations and play a role in the carcinogenesis of PAs. This study aims to predict in vivo genotoxicity for two well-studied PAs, lasiocarpine and riddelliine, in rat using in vitro genotoxicity data and physiologically based kinetic (PBK) modelling-based reverse dosimetry. The phosphorylation of histone protein H2AX was used as a quantitative surrogate endpoint for in vitro genotoxicity of lasiocarpine and riddelliine in primary rat hepatocytes and human HepaRG cells. The in vitro concentration-response curves obtained from primary rat hepatocytes were subsequently converted to in vivo dose-response curves from which points of departure (PoDs) were derived that were compared to available in vivo genotoxicity data. The results showed that the predicted PoDs for lasiocarpine and riddelliine were comparable to in vivo genotoxicity data. It is concluded that this quantitative in vitro-in silico approach provides a method to predict in vivo genotoxicity for the large number of PAs for which in vivo genotoxicity data are lacking by integrating in vitro genotoxicity assays with PBK modelling-facilitated reverse dosimetry.
Collapse
|
25
|
Intestinal and hepatic biotransformation of pyrrolizidine alkaloid N-oxides to toxic pyrrolizidine alkaloids. Arch Toxicol 2019; 93:2197-2209. [PMID: 31222523 DOI: 10.1007/s00204-019-02499-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 06/17/2019] [Indexed: 10/26/2022]
Abstract
Pyrrolizidine alkaloids (PAs) are among the most significant groups of phytotoxins present in more than 6000 plants in the world. Hepatotoxic retronecine-type PAs and their corresponding N-oxides usually co-exist in plants. Although PA-induced hepatotoxicity is known for a long time and has been extensively studied, the toxicity of PA N-oxide is rarely investigated. Recently, we reported PA N-oxide-induced hepatotoxicity in humans and rodents and also suggested the association of such toxicity with metabolic conversion of PA N-oxides to the corresponding toxic PAs. However, the detailed biochemical mechanism of PA N-oxide-induced hepatotoxicity is largely unknown. The present study investigated biotransformation of four representative cyclic retronecine-type PA N-oxides to their corresponding PAs in both gastrointestinal tract and liver. The results demonstrated that biotransformation of PA N-oxides to PAs was mediated by both intestinal microbiota and hepatic cytochrome P450 monooxygenases (CYPs), in particular CYP1A2 and CYP2D6. Subsequently, the formed PAs were metabolically activated predominantly by hepatic CYPs to form reactive metabolites exerting hepatotoxicity. Our findings delineated, for the first time, that the metabolism-mediated mechanism of PA N-oxide intoxication involved metabolic reduction of PA N-oxides to their corresponding PAs in both intestine and liver followed by oxidative bioactivation of the resultant PAs in the liver to generate reactive metabolites which interact with cellular proteins leading to hepatotoxicity. In addition, our results raised a public concern and also encouraged further investigations on potentially remarkable variations in PA N-oxide-induced hepatotoxicity caused by significantly altered intestinal microbiota due to individual differences in diets, life styles, and medications.
Collapse
|
26
|
Kast C, Kilchenmann V, Reinhard H, Bieri K, Zoller O. Pyrrolizidine Alkaloids: The Botanical Origin of Pollen Collected during the Flowering Period of Echium vulgare and the Stability of Pyrrolizidine Alkaloids in Bee Bread. Molecules 2019; 24:E2214. [PMID: 31200507 PMCID: PMC6631664 DOI: 10.3390/molecules24122214] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/07/2019] [Accepted: 06/09/2019] [Indexed: 01/15/2023] Open
Abstract
Previous studies have shown that pollen products sold as nutritional supplements and used in apitherapy may contain toxic pyrrolizidine alkaloids (PAs) if bees collect pollen from PA-containing plants, such as Echium vulgare. In this study, the botanical origin of pollen from two observation sites was studied. Despite a high PA content in pollen samples that bees collected during E. vulgare's flowering period, bees were found to collect relatively few Echium pollen loads. Thus, the monitoring of pollen loads collected at the apiaries is unviable to estimate the risk of PA contamination in pollen or bee bread. In a second step, the stability of PAs in bee bread samples containing PAs at concentrations of 2538 ng/g and 98 ng/g was assessed over a period of five or six months, respectively. No significant PA reduction was observed in bee bread stored at 15 °C, but there were overall PA reductions of 39% and 33% in bee bread stored at 30 °C, reflecting hive conditions. While PA N-oxides decreased over time, other types of PAs remained relatively stable. Monitoring PAs in pollen products remains important to ensure consumer safety and should include echivulgarine (and its N-oxide), the major PA type found in pollen from E. vulgare.
Collapse
Affiliation(s)
- Christina Kast
- Agroscope, Swiss Bee Research Centre, Schwarzenburgstrasse 161, 3003 Bern, Switzerland.
| | - Verena Kilchenmann
- Agroscope, Swiss Bee Research Centre, Schwarzenburgstrasse 161, 3003 Bern, Switzerland.
| | - Hans Reinhard
- Federal Food Safety and Veterinary Office (FSVO), Risk Assessment Division, 3003 Bern, Switzerland.
| | - Katharina Bieri
- Biologisches Institut für Pollenanalyse K. Bieri GmbH, Talstrasse 23, 3122 Kehrsatz, Switzerland.
| | - Otmar Zoller
- Federal Food Safety and Veterinary Office (FSVO), Risk Assessment Division, 3003 Bern, Switzerland.
| |
Collapse
|
27
|
Chen L, Mulder PPJ, Peijnenburg A, Rietjens IMCM. Risk assessment of intake of pyrrolizidine alkaloids from herbal teas and medicines following realistic exposure scenarios. Food Chem Toxicol 2019; 130:142-153. [PMID: 31112705 DOI: 10.1016/j.fct.2019.05.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 05/13/2019] [Accepted: 05/15/2019] [Indexed: 12/17/2022]
Abstract
In this study five types of herbal teas were used to quantify the effect of comminution of the leaves on resulting PA exposure. Results show that PA levels extracted from intact leaves were consistently lower than from comminuted tea leaves. The Margin of Exposure (MOE) approach was applied to evaluate the consequences of this difference for the associated risks in the scenario of lifetime exposure. Furthermore, we considered medicinal use of these teas for shorter-than-lifetime exposure scenarios, and also analysed the risks of shorter-than-lifetime use of eight herbal medicines and 19 previously analysed plant food supplements. This analysis revealed that shorter-than-lifetime use resulted in MOE values < 10,000 upon use for 40-3450 weeks during a lifetime, with for only a limited number of herbal teas and medicines use of two weeks a year (150 weeks during a 75 year lifetime) would still raise a concern. It is concluded that taking more realistic conditions into account markedly reduces the concerns raised for these herbal preparations. These results also illustrate the need for development of a generally accepted method for taking short term exposure into account in risk assessment of compounds that are genotoxic and carcinogenic.
Collapse
Affiliation(s)
- Lu Chen
- Division of Toxicology, Wageningen University, PO Box 8000, 6700, EA Wageningen, the Netherlands.
| | - Patrick P J Mulder
- RIKILT Wageningen University & Research, PO Box 230, 6700, AE, Wageningen, the Netherlands
| | - Ad Peijnenburg
- RIKILT Wageningen University & Research, PO Box 230, 6700, AE, Wageningen, the Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, PO Box 8000, 6700, EA Wageningen, the Netherlands
| |
Collapse
|
28
|
Schramm S, Köhler N, Rozhon W. Pyrrolizidine Alkaloids: Biosynthesis, Biological Activities and Occurrence in Crop Plants. Molecules 2019; 24:E498. [PMID: 30704105 PMCID: PMC6385001 DOI: 10.3390/molecules24030498] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 12/13/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) are heterocyclic secondary metabolites with a typical pyrrolizidine motif predominantly produced by plants as defense chemicals against herbivores. They display a wide structural diversity and occur in a vast number of species with novel structures and occurrences continuously being discovered. These alkaloids exhibit strong hepatotoxic, genotoxic, cytotoxic, tumorigenic, and neurotoxic activities, and thereby pose a serious threat to the health of humans since they are known contaminants of foods including grain, milk, honey, and eggs, as well as plant derived pharmaceuticals and food supplements. Livestock and fodder can be affected due to PA-containing plants on pastures and fields. Despite their importance as toxic contaminants of agricultural products, there is limited knowledge about their biosynthesis. While the intermediates were well defined by feeding experiments, only one enzyme involved in PA biosynthesis has been characterized so far, the homospermidine synthase catalyzing the first committed step in PA biosynthesis. This review gives an overview about structural diversity of PAs, biosynthetic pathways of necine base, and necic acid formation and how PA accumulation is regulated. Furthermore, we discuss their role in plant ecology and their modes of toxicity towards humans and animals. Finally, several examples of PA-producing crop plants are discussed.
Collapse
Affiliation(s)
- Sebastian Schramm
- Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Liesel-Beckmann-Straße 1, 85354 Freising, Germany.
| | - Nikolai Köhler
- Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Liesel-Beckmann-Straße 1, 85354 Freising, Germany.
| | - Wilfried Rozhon
- Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Liesel-Beckmann-Straße 1, 85354 Freising, Germany.
| |
Collapse
|
29
|
Ahmad L, He Y, Hao JC, Semotiuk A, Liu QR, Mazari P. Toxic pyrrolizidine alkaloids provide a warning sign to overuse of the ethnomedicine Arnebia benthamii. JOURNAL OF ETHNOPHARMACOLOGY 2018; 210:88-94. [PMID: 28807851 DOI: 10.1016/j.jep.2017.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/09/2017] [Indexed: 06/07/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE From early times man has used medicinal plants for the treatment of various ailments and basic health care needs. The use of herbal medicines has increased day by day and with this, so do reports of adverse events, poisoning, and suspected toxicity. Similarly, the indigenous communities of Neelum Valley in Azad Kashmir commonly use Arnebia benthamii (Wall. ex G.Don) I.M.Johnst. for medicinal purposes to treat various human aliments. Besides their medicinal uses, it also contains hepatotoxic pyrrolizidine alkaloids (PAs). AIM OF THE STUDY This explorative study underscores two major aspects about this herbal medicine. Firstly we aimed to document the traditional therapeutic uses of Arnebia benthamii in Neelum Valley, Azad Kashmir. Secondly, to determine the presence or absence of hepatotoxic pyrrolizidine alkaloids and if they are within the suggested limit for the use of herbs in excess. MATERIALS AND METHODS Interviews, group discussions, and inquiries were carried out from July to September 2016 with local indigenous and elder people. In the laboratory, the plant was investigated for pyrrolizidine alkaloids by using high performance liquid chromatography (HPLC). RESULTS A total of 30 respondents were interviewed. They explained the preferred preparation, parts used, and treatment indications. Treatment of fever along with kidney and liver problems are the three principle uses. Among the different parts of Arnebia benthamii, 43% respondents preferred aerial parts for the herbal formulation, followed by whole plants, and leaves. Decoction was the major mode of preparation and all herbal preparations were administrated orally. This study reports, for the first time according to our literature review, a study of Arnebia benthamii with regard to PA determination. By using column Zorbax SB-Aq and acetonitrile-water gradient as the mobile phase, HPLC results showed that the aerial parts of the plant were PA positive, and (1) Europine, Heliotrine (2), Lycopsamine (3), and Echimidine (4) were identified. CONCLUSIONS This study has revealed two new findings of significance to herbal medicine producers, practitioners, and consumers of Arnebia benthamii First, local knowledge regarding the medicinal uses of Arnebia benthamii were documented in five sites of Neelum Valley, Azad Kashmir. The use of this plant by a large part of the population in the study area shows the importance for their therapeutic benefits. Unfortunately, the second finding of this study shows that Arnebia benthamii contains hepatotoxic PAs. Hence, we advised to the government regulatory authorities and non-governmental organizations that use of this plant as herbal medicine should be excluded before more accurate quality control tests.
Collapse
Affiliation(s)
- Latif Ahmad
- College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Yi He
- College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Jia-Chen Hao
- College of Life Science, Beijing Normal University, Beijing 100875, China
| | - Andrew Semotiuk
- Department of Botany and Plant Sciences, University of California, Riverside, CA 92507 USA
| | - Quan-Ru Liu
- College of Life Science, Beijing Normal University, Beijing 100875, China.
| | - Paras Mazari
- College of Life Science, Beijing Normal University, Beijing 100875, China
| |
Collapse
|
30
|
|
31
|
Kast C, Kilchenmann V, Reinhard H, Droz B, Lucchetti MA, Dübecke A, Beckh G, Zoller O. Chemical fingerprinting identifies Echium vulgare, Eupatorium cannabinum and Senecio spp. as plant species mainly responsible for pyrrolizidine alkaloids in bee-collected pollen. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2017; 35:316-327. [DOI: 10.1080/19440049.2017.1378443] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | | | - Hans Reinhard
- Federal Food Safety and Veterinary Office (FSVO), Risk Assessment Division, Bern, Switzerland
| | - Benoit Droz
- Agroscope, Swiss Bee Research Centre, Bern, Switzerland
| | - Matteo Angelo Lucchetti
- Agroscope, Swiss Bee Research Centre, Bern, Switzerland
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Arne Dübecke
- Quality Services International GmbH (QSI), Bremen, Germany
| | - Gudrun Beckh
- Quality Services International GmbH (QSI), Bremen, Germany
| | - Otmar Zoller
- Federal Food Safety and Veterinary Office (FSVO), Risk Assessment Division, Bern, Switzerland
| |
Collapse
|
32
|
He X, Xia Q, Woodling K, Lin G, Fu PP. Pyrrolizidine alkaloid-derived DNA adducts are common toxicological biomarkers of pyrrolizidine alkaloid N-oxides. J Food Drug Anal 2017; 25:984-991. [PMID: 28987376 PMCID: PMC9328871 DOI: 10.1016/j.jfda.2017.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
There are 660 pyrrolizidine alkaloids (PAs) and PA N-oxides present in the plants, with approximately half being possible carcinogens. We previously reported that a set of four PA-derived DNA adducts is formed in the liver of rats administered a series of hepatocarcinogenic PAs and a PA N-oxide. Based on our findings, we hypothesized that this set of DNA adducts is a common biological biomarker of PA-induced liver tumor formation. In this study, we determined that rat liver microsomal metabolism of five hepatocarcinogenic PAs (lasiocarpine, retrorsine, riddelliine, monocrotaline, and heliotrine) and their corresponding PA N-oxides produced the same set of DNA adducts. Among these compounds, lasiocarpine N-oxide, retrorsine N-oxide, monocrotaline N-oxide, and heliotrine N-oxide are for first time shown to be able to produce these DNA adducts. These results further support the role of these DNA adducts as potential common biomarkers of PA-induced liver tumor initiation.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079,
United States
| | - Qingsu Xia
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079,
United States
| | - Kellie Woodling
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079,
United States
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong,
Hong Kong
| | - Peter P. Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079,
United States
- Corresponding author. Fax: +1 870 543 7136. E-mail address: (P.P. Fu)
| |
Collapse
|
33
|
Yang M, Ruan J, Gao H, Li N, Ma J, Xue J, Ye Y, Fu PPC, Wang J, Lin G. First evidence of pyrrolizidine alkaloid N-oxide-induced hepatic sinusoidal obstruction syndrome in humans. Arch Toxicol 2017; 91:3913-3925. [PMID: 28620673 DOI: 10.1007/s00204-017-2013-y] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 06/08/2017] [Indexed: 02/06/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are among the most potent phytotoxins widely distributed in plant species around the world. PA is one of the major causes responsible for the development of hepatic sinusoidal obstruction syndrome (HSOS) and exerts hepatotoxicity via metabolic activation to form the reactive metabolites, which bind with cellular proteins to generate pyrrole-protein adducts, leading to hepatotoxicity. PA N-oxides coexist with their corresponding PAs in plants with varied quantities, sometimes even higher than that of PAs, but the toxicity of PA N-oxides remains unclear. The current study unequivocally identified PA N-oxides as the sole or predominant form of PAs in 18 Gynura segetum herbal samples ingested by patients with liver damage. For the first time, PA N-oxides were recorded to induce HSOS in human. PA N-oxide-induced hepatotoxicity was further confirmed on mice orally dosed of herbal extract containing 170 μmol PA N-oxides/kg/day, with its hepatotoxicity similar to but potency much lower than the corresponding PAs. Furthermore, toxicokinetic study after a single oral dose of senecionine N-oxide (55 μmol/kg) on rats revealed the toxic mechanism that PA N-oxides induced hepatotoxicity via their biotransformation to the corresponding PAs followed by the metabolic activation to form pyrrole-protein adducts. The remarkable differences in toxicokinetic profiles of PAs and PA N-oxides were found and attributed to their significantly different hepatotoxic potency. The findings of PA N-oxide-induced hepatotoxicity in humans and rodents suggested that the contents of both PAs and PA N-oxides present in herbs and foods should be regulated and controlled in use.
Collapse
Affiliation(s)
- Mengbi Yang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, Hong Kong
- Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines Between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Jianqing Ruan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, Hong Kong
- Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines Between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Hong Gao
- Division of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China
| | - Na Li
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, Hong Kong
| | - Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, Hong Kong
- Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines Between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Junyi Xue
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, Hong Kong
- Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines Between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Yang Ye
- Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines Between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, Hong Kong, People's Republic of China
- State Key Laboratory of Drug Research and Natural Products Chemistry Department, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, People's Republic of China
| | | | - Jiyao Wang
- Division of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, Hong Kong.
- Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines Between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
| |
Collapse
|
34
|
He X, Xia Q, Fu PP. 7-Glutathione-pyrrole and 7-cysteine-pyrrole are potential carcinogenic metabolites of pyrrolizidine alkaloids. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2017; 35:69-83. [PMID: 28418776 DOI: 10.1080/10590501.2017.1298358] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Many pyrrolizidine alkaloids (PAs) are hepatotoxic, genotoxic, and carcinogenic phytochemicals. Metabolism of PAs in vivo generates four (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-DNA adducts that have been proposed to be responsible for PA-induced liver tumor formation in rats. In this present study, we determined that the same set of DHP-DNA adducts was formed upon the incubation of 7-glutathione-DHP and 7-cysteine-DHP with cultured human hepatocarcinoma HepG2 cells. These results suggest that 7-glutathione-DHP and 7-cysteine-DHP are reactive metabolites of PAs that can bind to cellular DNA to form DHP-DNA adducts in HepG2 cells, and can potentially initiate liver tumor formation.
Collapse
Affiliation(s)
- Xiaobo He
- a National Center for Toxicological Research , US Food and Drug Administration , Jefferson , Arkansas , USA
| | - Qingsu Xia
- a National Center for Toxicological Research , US Food and Drug Administration , Jefferson , Arkansas , USA
| | - Peter P Fu
- a National Center for Toxicological Research , US Food and Drug Administration , Jefferson , Arkansas , USA
| |
Collapse
|
35
|
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.
Collapse
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.
| |
Collapse
|
36
|
Fu PP. Pyrrolizidine Alkaloids: Metabolic Activation Pathways Leading to Liver Tumor Initiation. Chem Res Toxicol 2016; 30:81-93. [DOI: 10.1021/acs.chemrestox.6b00297] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Peter P. Fu
- National Center for Toxicological
Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| |
Collapse
|
37
|
Xia Q, Zhao Y, Lin G, Beland FA, Cai L, Fu PP. Pyrrolizidine Alkaloid-Protein Adducts: Potential Non-invasive Biomarkers of Pyrrolizidine Alkaloid-Induced Liver Toxicity and Exposure. Chem Res Toxicol 2016; 29:1282-92. [DOI: 10.1021/acs.chemrestox.6b00120] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Qingsu Xia
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| | - Yuewei Zhao
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| | - Ge Lin
- School
of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR
| | - Frederick A. Beland
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| | - Lining Cai
- Biotranex LLC, Monmouth Junction, New Jersey 08852, United States
| | - Peter P. Fu
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| |
Collapse
|
38
|
Lucchetti MA, Glauser G, Kilchenmann V, Dübecke A, Beckh G, Praz C, Kast C. Pyrrolizidine Alkaloids from Echium vulgare in Honey Originate Primarily from Floral Nectar. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:5267-73. [PMID: 27244472 DOI: 10.1021/acs.jafc.6b02320] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Pyrrolizidine alkaloids (PAs) in honey can be a potential human health risk. So far, it has remained unclear whether PAs in honey originate from pollen or floral nectar. We obtained honey, nectar, and plant pollen from two observation sites where Echium vulgare L. was naturally abundant. The PA concentration of honey was determined by targeted analysis using a high pressure liquid chromatography-mass spectrometry system (HPLC-MS/MS), allowing the quantification of six different PAs and PA-N-oxides present in E. vulgare. Echium-type PAs were detected up to 0.153 μg/g in honey. Nectar and plant pollen were analyzed by nontargeted analysis using ultrahigh pressure liquid chromatography-high resolution-mass spectrometry (UHPLC-HR-MS), allowing the detection of 10 alkaloids in small size samples. Echium-type PAs were detected between 0.3-95.1 μg/g in nectar and 500-35000 μg/g in plant pollen. The PA composition in nectar and plant pollen was compared to the composition in honey. Echimidine (+N-oxide) was the main alkaloid detected in honey and nectar samples, while echivulgarine (+N-oxide) was the main PA found in plant pollen. These results suggest that nectar contributes more significantly to PA contamination in honey than plant pollen.
Collapse
Affiliation(s)
- Matteo A Lucchetti
- Agroscope, Swiss Bee Research Centre, Schwarzenburgstrasse 161, 3003 Bern, Switzerland
- Institute of Biology, Laboratory of Fundamental and Applied Research in Chemical Ecology (FARCE), University of Neuchâtel , Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Gaetan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of Neuchâtel , Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Verena Kilchenmann
- Agroscope, Swiss Bee Research Centre, Schwarzenburgstrasse 161, 3003 Bern, Switzerland
| | - Arne Dübecke
- Quality Services International GmbH (QSI), Flughafendamm 9a, 28199 Bremen, Germany
| | - Gudrun Beckh
- Quality Services International GmbH (QSI), Flughafendamm 9a, 28199 Bremen, Germany
| | - Christophe Praz
- Institute of Biology, Laboratory of Fundamental and Applied Research in Chemical Ecology (FARCE), University of Neuchâtel , Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Christina Kast
- Agroscope, Swiss Bee Research Centre, Schwarzenburgstrasse 161, 3003 Bern, Switzerland
| |
Collapse
|
39
|
Fu P, La S, MacMillan JB. 1,3-Oxazin-6-one Derivatives and Bohemamine-Type Pyrrolizidine Alkaloids from a Marine-Derived Streptomyces spinoverrucosus. JOURNAL OF NATURAL PRODUCTS 2016; 79:455-462. [PMID: 26489038 PMCID: PMC5435457 DOI: 10.1021/acs.jnatprod.5b00604] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Indexed: 06/05/2023]
Abstract
Two new 1,3-oxazin-6-one derivatives (1 and 2) and six new bohemamine-type pyrrolizidine alkaloids (3-8) were isolated from the marine-derived Streptomyces spinoverrucosus strain SNB-048. Their structures including the absolute configurations were fully elucidated on the basis of spectroscopic analysis, ECD spectra, quantum chemical calculations, and chemical methods. Compounds 1 and 2 possess a γ-lactam moiety and a 1,3-oxazin-6-one system.
Collapse
|
40
|
Cairns E, Hashmi MA, Singh AJ, Eakins G, Lein M, Keyzers R. Structure of Echivulgarine, a Pyrrolizidine Alkaloid Isolated from the Pollen of Echium vulgare. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:7421-7427. [PMID: 26273795 DOI: 10.1021/acs.jafc.5b02402] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
1,2-Dehydropyrrolizidine alkaloids are common toxic metabolites isolated from plants within the Boraginaceae, in particular from the genera Heliotropium and Echium. Previous studies have deduced the structures of these often potent bioactives based upon mass spectrometric evidence, but these identifications have not established conclusive connectivity and configurational data. Herein, we describe the isolation and full structural characterization of echivulgarine, occurring in the pollen of Echium vulgare and correct the structure previously ascribed to the compound, using a comprehensive combination of both experimental and calculated nuclear magnetic resonance and electronic circular dichroism spectroscopic data.
Collapse
Affiliation(s)
- Eric Cairns
- AsureQuality Ltd. , P.O. Box 31242, Lower Hutt 5040, New Zealand
| | - Muhammad Ali Hashmi
- School of Chemical & Physical Sciences, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand
| | - A Jonathan Singh
- School of Chemical & Physical Sciences, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand
| | - Galen Eakins
- School of Chemical & Physical Sciences, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand
| | - Matthias Lein
- School of Chemical & Physical Sciences, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand
- Centre for Theoretical Chemistry and Physics (CTCP), New Zealand Institute for Advanced Study, Massey University Auckland , Auckland, New Zealand
| | - Robert Keyzers
- School of Chemical & Physical Sciences, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand
- Centre for Biodiscovery, Victoria University of Wellington , P.O. Box 600, Wellington 6140, New Zealand
| |
Collapse
|
41
|
Lyu C, Zhou W, Zhang Y, Zhang S, Kou F, Wei H, Zhang N, Zuo Z. Identification and characterization of in vitro and in vivo metabolites of steroidal alkaloid veratramine. Biopharm Drug Dispos 2015; 36:308-24. [PMID: 25765359 DOI: 10.1002/bdd.1942] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 02/11/2015] [Accepted: 02/25/2015] [Indexed: 12/22/2022]
Abstract
Veratramine, a steroidal alkaloid originating from Veratrum nigrum L., has demonstrated distinct anti-tumor and anti-hypertension effects, however, its metabolism has rarely been explored. The objective of the current study was to provide a comprehensive investigation of its metabolic pathways. The in vitro metabolic profiles of veratramine were evaluated by incubating it with liver microsomes and cytosols. The in vivo metabolic profiles in plasma, bile, urine and feces were monitored by UPLC-MS/MS after oral (20 mg/kg) and i.v. (50 µg/kg) administration in rats. Meanwhile, related P450s inhibitors and recombinant P450s and SULTs were used to identify the isozymes responsible for its metabolism. Eleven metabolites of veratramine, including seven hydroxylated, two sulfated and two glucuronidated metabolites, were characterized. Unlike most alkaloids, the major reactive sites of veratramine were on ring A and B instead of on the amine moiety. CYP2D6 was the major isozyme mediating hydroxylation, and substrate inhibition was observed with a Vmax , Ki and Clint of 2.05 ± 0.53 nmol/min/mg, 33.08 ± 10.13 µ m and 13.58 ± 1.27 µL/min/mg. SULT2A1, with Km , Vmax and Clint values of 19.37 ± 0.87 µ m, 1.51 ± 0.02 nmol/min/mg and 78.19 ± 8.57 µL/min/mg, was identified as the major isozyme contributing to its sulfation. In conclusion, CYP2D6 and SULT2A1 mediating hydroxylation and sulfation were identified as the major biotransformation for veratramine.
Collapse
Affiliation(s)
- Chunming Lyu
- Technology Laboratory Center, Shanghai University of Traditional Chinese Medicine, Shanghai, PR China.,School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
| | - Wenbin Zhou
- Center for Chinese Medical Therapy and Systems Biology, Shanghai University of Traditional Chinese Medicine, Shanghai, PR China
| | - Yufeng Zhang
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
| | - Shen Zhang
- Department of Rehabilitation, Changzheng Hospital Affiliated to Second Military Medicine University, Shanghai, 200003, PR China
| | - Fang Kou
- Center for Chinese Medical Therapy and Systems Biology, Shanghai University of Traditional Chinese Medicine, Shanghai, PR China
| | - Hai Wei
- Center for Chinese Medical Therapy and Systems Biology, Shanghai University of Traditional Chinese Medicine, Shanghai, PR China
| | - Ning Zhang
- Technology Laboratory Center, Shanghai University of Traditional Chinese Medicine, Shanghai, PR China
| | - Zhong Zuo
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR
| |
Collapse
|
42
|
An in vitro comparison of the cytotoxic potential of selected dehydropyrrolizidine alkaloids and some N-oxides. Toxicon 2015; 97:36-45. [PMID: 25666399 DOI: 10.1016/j.toxicon.2015.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/29/2015] [Accepted: 02/05/2015] [Indexed: 11/20/2022]
Abstract
Plants producing dehydropyrrolizidine alkaloids (DHPAs) are found throughout the world and they are dangerous to human and animal health. Several DHPAs are carcinogenic but only riddelliine has been classified as a potential human carcinogen by the National Toxicology Program. As DHPA-related carcinogenicity is probably linked to cytotoxicity, a model of CRL-2118 chicken hepatocyte cytotoxicity was developed to compare equimolar DHPA exposures between 19 and 300 μM. Alkaloid-related cytotoxicity was estimated using cytomorphology, cell viability reflected by mitochondrial function and cellular degeneration reflected by media lactate dehydrogenase activity. Lasiocarpine induced cytotoxicity and decreased cell viability in a concentration dependent manner at 24 h. At similar concentrations and exposures of 48 and 72 h, seneciphylline, senecionine, monocrotaline and riddelliine were cytotoxic. None of the DHPA-N-oxides were significantly cytotoxic at these concentrations. Using graphic analyses the median cytotoxic concentration (DHPA concentration that produced ½ the maximum response) were estimated. The estimated descending order of cytotoxicity was lasiocarpine, seneciphylline, senecionine, heliotrine, riddelliine, monocrotaline, riddelliine-N-oxide, lycopsamine, intermedine, lasiocarpine-N-oxide and senecionine-N-oxide. This comparison identifies DHPAs that were more cytotoxic than carcinogenic riddelliine. Additional studies to better characterize the carcinogenic potential of these alkaloids are essential to better determine the risk they each may pose for human and animal health.
Collapse
|
43
|
Edgar JA, Molyneux RJ, Colegate SM. Pyrrolizidine Alkaloids: Potential Role in the Etiology of Cancers, Pulmonary Hypertension, Congenital Anomalies, and Liver Disease. Chem Res Toxicol 2014; 28:4-20. [PMID: 25483859 DOI: 10.1021/tx500403t] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Large outbreaks of acute food-related poisoning, characterized by hepatic sinusoidal obstruction syndrome, hemorrhagic necrosis, and rapid liver failure, occur on a regular basis in some countries. They are caused by 1,2-dehydropyrrolizidine alkaloids contaminating locally grown grain. Similar acute poisoning can also result from deliberate or accidental consumption of 1,2-dehydropyrrolizidine alkaloid-containing herbal medicines, teas, and spices. In recent years, it has been confirmed that there is also significant, low-level dietary exposure to 1,2-dehydropyrrolizidine alkaloids in many countries due to consumption of common foods such as honey, milk, eggs, salads, and meat. The level of 1,2-dehydropyrrolizidine alkaloids in these foods is generally too low and too intermittent to cause acute toxicity. However, these alkaloids are genotoxic and can cause slowly developing chronic diseases such as pulmonary arterial hypertension, cancers, cirrhosis, and congenital anomalies, conditions unlikely to be easily linked with dietary exposure to 1,2-dehydropyrrolizidine alkaloids, especially if clinicians are unaware that such dietary exposure is occurring. This Perspective provides a comprehensive review of the acute and chronic toxicity of 1,2-dehydropyrrolizidine alkaloids and their potential to initiate certain chronic diseases, and suggests some associative considerations or indicators to assist in recognizing specific cases of diseases that may have resulted from dietary exposure to these hazardous natural substances. If it can be established that low-level dietary exposure to 1,2-dehydropyrrolizidine alkaloids is a significant cause of some of these costly and debilitating diseases, then this should lead to initiatives to reduce the level of these alkaloids in the food chain.
Collapse
Affiliation(s)
- John A Edgar
- CSIRO Food and Nutrition , 11 Julius Avenue, North Ryde, NSW 2113, Australia
| | - Russell J Molyneux
- Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo , 34 Rainbow Drive, Hilo, Hawaii 96720, United States
| | - Steven M Colegate
- Poisonous Plant Research Laboratory, ARS/USDA , 1150 East 1400 North, Logan, Utah 84341, United States
| |
Collapse
|
44
|
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.
Collapse
Affiliation(s)
- Jeremy Robertson
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
| | | |
Collapse
|
45
|
Fang L, Xiong A, Yang X, Cheng W, Yang L, Wang Z. Mass-spectrometry-directed analysis and purification of pyrrolizidine alkaloid cis/trans isomers in Gynura japonica. J Sep Sci 2014; 37:2032-8. [PMID: 24840731 DOI: 10.1002/jssc.201400314] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 05/02/2014] [Accepted: 05/06/2014] [Indexed: 11/10/2022]
Abstract
Pyrrolizidine alkaloids are highly hepatotoxic natural chemicals that produce irreversible chronic and acute hepatotoxic effects on human beings. Purification of large amounts of pyrrolizidine alkaloids is necessary for toxicity studies. In this study, an efficient method for targeted analysis and purification of pyrrolizidine alkaloid cis/trans isomers from herbal materials was developed for the first time. Targeted analysis of the hepatotoxic pyrrolizidine alkaloids was performed by liquid chromatography with tandem mass spectrometry (precursor ion scan and daughter ion scan), and the purification of pyrrolizidine alkaloids was achieved with a mass-directed auto purification system. The extraction and preparative liquid chromatography conditions were optimized. The developed method was applied to analysis of Gynura japonica (Thunb.) Juel., a herbal medicine traditionally used for detumescence and relieving pain but is potentially hepatotoxic as it contains pyrrolizidine alkaloids. Twelve pyrrolizidine alkaloids (six cis/trans isomer pairs) were identified with reference compounds or characterized by liquid chromatography with tandem mass spectrometry, and five individual pyrrolizidine alkaloids, including (E)-seneciphylline, seneciphylline, integerrimine, senecionine, and seneciphyllinine, were prepared from G. japonica roots with high efficiency. The results of this work provide a new technique for the preparation of large amounts of pyrrolizidine alkaloid reference substances, which will also benefit toxicological studies of pyrrolizidine alkaloids and treatments for pyrrolizidine alkaloid-induced toxicity.
Collapse
Affiliation(s)
- Lianxiang Fang
- The Ministry of Education (MOE) Key Laboratory for Standardization of Chinese Medicines and the State Administration of TCM (SATCM) Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | | | | | | | | | | |
Collapse
|
46
|
Yao J, Li CG, Gong LK, Feng CC, Li CZ, Gao M, Luan Y, Qi XM, Ren J. Hepatic cytochrome P450s play a major role in monocrotaline-induced renal toxicity in mice. Acta Pharmacol Sin 2014; 35:292-300. [PMID: 24362331 DOI: 10.1038/aps.2013.145] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 09/09/2013] [Indexed: 12/13/2022] Open
Abstract
AIM Monocrotaline (MCT) in plants of the genus Crotalaria induces significant toxicity in multiple organs including the liver, lung and kidney. Metabolic activation of MCT is required for MCT-induced toxicity. In this study, we attempted to determine whether the toxicity of MCT in kidney was a consequence of the metabolic activation of MCT in the liver. METHODS Liver-specific cytochrome P450 reductase-null (Null) mice, wild-type (WT) mice and CYP3A inhibitor ketoconazole-pretreated WT (KET-WT) mice were examined. The mice were injected with MCT (300, 400, or 500 mg/kg, ip), and hepatotoxicity and nephrotoxicity were examined 24 h after MCT treatment. The levels of MCT and its metabolites in the blood, liver, lung, kidney and bile were determined using LC-MS analysis. RESULTS Treatment of WT mice with MCT increased the serum levels of alanine aminotransferase, hyaluronic acid, urea nitrogen and creatinine in a dose-dependent manner. Histological examination revealed that MCT (500 mg/kg) caused severe liver injury and moderate kidney injury. In contrast, these pathological abnormalities were absent in Null and KET-WT mice. After injection of MCT (400 and 500 mg/kg), the plasma, liver, kidney and lung of WT mice had significantly lower MCT levels and much higher N-oxide metabolites contents in compared with those of Null and KET-WT mice. Furthermore, WT mice had considerably higher levels of tissue-bound pyrroles and bile GSH-conjugated MCT metabolites compared with Null and KET-WT mice. CONCLUSION Cytochrome P450s in mouse liver play a major role in the metabolic activation of MCT and thus contribute to MCT-induced renal toxicity.
Collapse
|
47
|
Wang CC, Xia Q, Li M, Wang S, Zhao Y, Tolleson WH, Yin JJ, Fu PP. Metabolic activation of pyrrolizidine alkaloids leading to phototoxicity and photogenotoxicity in human HaCaT keratinocytes. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2014; 32:362-384. [PMID: 25436474 DOI: 10.1080/10590501.2014.969980] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Pyrrolizidine alkaloids, produced by a large number of poisonous plants with wide global distribution, are associated with genotoxicity, tumorigenicity, and hepatotoxicity in animals and humans. Mammalian metabolism converts pyrrolizidine alkaloids to reactive pyrrolic metabolites (dehydropyrrolizidine alkaloids) that form covalent protein and DNA adducts. Although a mechanistic understanding is currently unclear, pyrrolizidine alkaloids can cause secondary (hepatogenous) photosensitization and induce skin cancer. In this study, the phototoxicity of monocrotaline, riddelliine, dehydromonocrotaline, dehydroriddelliine, and dehydroretronecine (DHR) in human HaCaT keratinocytes under ultraviolet A (UVA) irradiation was determined. UVA irradiation of HaCaT cells treated with dehydromonocrotaline, dehydroriddelline, and DHR resulted in increased release of lactate dehydrogenase and enhanced photocytotoxicity proportional to the UVA doses. UVA-induced photochemical DNA damage also increased proportionally with dehydromonocrotaline and dehydroriddelline. UVA treatment potentiated the formation of 8-hydroxy-2'-deoxyguanosine DNA adducts induced by dehydromonocrotaline in HaCaT skin keratinocytes. Using electron spin resistance trapping, we found that UVA irradiation of dehydromonocrotaline and dehydroriddelliine generates reactive oxygen species (ROS), including hydroxyl radical, singlet oxygen, and superoxide, and electron transfer reactions, indicating that cytotoxicity and genotoxicity of these compounds could be mediated by ROS. Our results suggest that dehydropyrrolizidine alkaloids formed or delivered to the skin cause pyrrolizidine alkaloid-induced secondary photosensitization and possible skin cancer.
Collapse
Affiliation(s)
- Chia-Chi Wang
- a National Center for Toxicological Research , US Food and Drug Administration , Jefferson , Arkansas , USA
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Xia Q, Zhao Y, Von Tungeln LS, Doerge DR, Lin G, Cai L, Fu PP. Pyrrolizidine Alkaloid-Derived DNA Adducts as a Common Biological Biomarker of Pyrrolizidine Alkaloid-Induced Tumorigenicity. Chem Res Toxicol 2013; 26:1384-96. [DOI: 10.1021/tx400241c] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qingsu Xia
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| | - Yuewei Zhao
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| | - Linda S. Von Tungeln
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| | - Daniel R. Doerge
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| | - Ge Lin
- School
of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR
| | - Lining Cai
- Biotranex LLC, Monmouth Junction, New Jersey 08852, United States
| | - Peter P. Fu
- National Center for Toxicological Research, Jefferson, Arkansas 72079, United States
| |
Collapse
|
49
|
Fu PP, Xia Q, Zhao Y, Wang S, Yu H, Chiang HM. Phototoxicity of herbal plants and herbal products. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2013; 31:213-255. [PMID: 24024520 DOI: 10.1080/10590501.2013.824206] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Plants are used by humans in daily life in many different ways, including as food, herbal medicines, and cosmetics. Unfortunately, many natural plants and their chemical constituents are photocytotoxic and photogenotoxic, and these phototoxic phytochemicals are widely present in many different plant families. To date, information concerning the phototoxicity and photogenotoxicity of many plants and their chemical constituents is limited. In this review, we discuss phototoxic plants and their major phototoxic constituents; routes of human exposure; phototoxicity of these plants and their constituents; general mechanisms of phototoxicity of plants and phototoxic components; and several representative phototoxic plants and their photoactive chemical constituents.
Collapse
Affiliation(s)
- Peter P Fu
- a National Center for Toxicological Research , Jefferson , Arkansas , USA
| | | | | | | | | | | |
Collapse
|
50
|
Ruan J, Li N, Xia Q, Fu PP, Peng S, Ye Y, Lin G. Characteristic ion clusters as determinants for the identification of pyrrolizidine alkaloid N-oxides in pyrrolizidine alkaloid-containing natural products using HPLC-MS analysis. JOURNAL OF MASS SPECTROMETRY : JMS 2012; 47:331-337. [PMID: 22431459 DOI: 10.1002/jms.2969] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Pyrrolizidine alkaloid (PA)-containing plants are widely distributed in the world. PAs are hepatotoxic, affecting livestock and humans. PA N-oxides are often present together with PAs in plants and also exhibit hepatotoxicity but with less potency. HPLC-MS is generally used to analyze PA-containing herbs, although PA references are unavailable in most cases. However, to date, without reference standards, HPLC-MS methodology cannot distinguish PA N-oxides from PAs because they both produce the same characteristic ions in mass spectra. In the present study, the mass spectra of 10 PA N-oxides and the corresponding PAs were systemically investigated using HPLC-MS to define the characteristic mass fragment ions specific to PAs and PA N-oxides. Mass spectra of toxic retronecine-type PA N-oxides exhibited two characteristic ion clusters at m/z 118-120 and 136-138. These ion clusters were produced by three unique fragmentation pathways of PA N-oxides and were not found in their corresponding PAs. Similarly, the nontoxic platynecine-type PA N-oxides also fragmented via three similar pathways to form two characteristic ion clusters at m/z 120-122 and 138-140. Further application of using these characteristic ion clusters allowed successful and rapid identification of PAs and PA N-oxides in two PA-containing herbal plants. Our results demonstrated, for the first time, that these characteristic ion clusters are unique determinants to discriminate PA N-oxides from PAs even without the availability of reference samples. Our findings provide a novel and specific method to differentiate PA N-oxides from PAs in PA-containing natural products, which is crucial for the assessment of their intoxication.
Collapse
Affiliation(s)
- Jianqing Ruan
- School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | | | | | | | | | | | | |
Collapse
|