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Fan Y, Wang M, Zhang Q, Ouyang S, Mao W, Xu C, Wang M, Long C. Traditional uses, phytochemistry, pharmacology, toxicity and clinical application of traditional Chinese medicine Cynoglossum amabile: a review. Front Pharmacol 2024; 15:1325283. [PMID: 38655180 PMCID: PMC11035817 DOI: 10.3389/fphar.2024.1325283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
Cynoglossum amabile, a member of the Boraginaceae family, is a well-known traditional Chinese medicine and ethnomedicine known as Daotihu. Despite several studies confirming the presence of bioactive pyrrolizidine alkaloids such as amabiline, ambelline, echinatine, europine, and others in C. amabile, there has been no comprehensive review of its traditional uses, phytochemistry, and pharmacology thus far. This review was conducted by thoroughly examining the literature and analyzing network databases. It covers various aspects of C. amabile, including botanical characteristics, geographical distribution, traditional applications, phytochemistry, pharmacological activities, toxicology, and clinical applications. The results have shown that C. amabile has been traditionally used for medicinal, edible, and ornamental purposes in China for many centuries. The whole plant, root, and leaf of C. amabile are used by different ethnic groups, such as Lisu, Bai, Naxi, Yi, Jinuo, and Han, to treat malaria, hepatitis, dysentery, leucorrhea, tuberculosis cough, fracture, joint dislocation, trauma bleeding, and skin carbuncle abscess. A total of 47 chemical components, including alkaloids (pyrrolizidine alkaloids, PAs), sterols, organic acids, and saccharides, were isolated from C. amabile. Pharmacological studies show that the chemical extracts of C. amabile possess various biological activities, such as anti-inflammatory, anti-tumor, anti-microbial, cardiovascular effects, ganglionic action, and acetylcholinesterase inhibition. However, it is important to note that C. amabile exhibits hepatotoxicity, with its toxicity being linked to its primary PAs components. Although preliminary studies suggest potential applications in the treatment of prostate diseases and alopecia, further research is needed to validate these clinical uses. Our review highlights the traditional uses, phytochemistry, biological activity, toxicity, and clinical applications of C. amabile. It emphasizes the essential guiding role of the indigenous medicinal knowledge system in developing new drugs. Previous studies have shown that the phytochemical and pharmacological characteristics of C. amabile are significantly related to its traditional medicinal practices. Cynoglossum amabile has excellent market potential and can be further analyzed in terms of phytochemistry, pharmacology, and toxicology, which are critical for its clinical drug safety, quality evaluation, and resource development.
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Affiliation(s)
- Yanxiao Fan
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Miaomiao Wang
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Qing Zhang
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Shuqi Ouyang
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
| | - Wenhui Mao
- Xianggelila Bureau of Forestry and Grassland, Beijing, China
| | - Congli Xu
- Baoshan Administrative of Gaoligongshan National Nature Reserve, Baoshan, China
| | - Min Wang
- College of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing, China
- BTBU-TANGYI Innovation Center for the Evaluation of the Safety and Efficacy of Bioengineering Raw Materials, Beijing, China
| | - Chunlin Long
- Key Laboratory of Ecology and Environment in Minority Areas (Minzu University of China), National Ethnic Affairs Commission, Beijing, China
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
- Key Laboratory of Ethnomedicine (Minzu University of China), Ministry of Education, Beijing, China
- Institute of National Security Studies, Minzu University of China, Beijing, China
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Tábuas B, Cruz Barros S, Diogo C, Cavaleiro C, Sanches Silva A. Pyrrolizidine Alkaloids in Foods, Herbal Drugs, and Food Supplements: Chemistry, Metabolism, Toxicological Significance, Analytical Methods, Occurrence, and Challenges for Future. Toxins (Basel) 2024; 16:79. [PMID: 38393157 PMCID: PMC10892171 DOI: 10.3390/toxins16020079] [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: 11/16/2023] [Revised: 12/20/2023] [Accepted: 01/23/2024] [Indexed: 02/25/2024] Open
Abstract
Consumers are increasingly seeking natural alternatives to chemical compounds, including the use of dried aromatic plants as seasonings instead of salt. However, the presence of pyrrolizidine alkaloids (PAs) in food supplements and dried plants has become a concern because of their link to liver diseases and their classification as carcinogenic by the International Agency for Research on Cancer (IARC). Despite European Union (EU) Regulation (EU) 2023/915, non-compliance issues persist, as indicated by alerts on the Rapid Alert System for Food and Feed (RASFF) portal. Analyzing PAs poses a challenge because of their diverse chemical structures and low concentrations in these products, necessitating highly sensitive analytical methods. Despite these challenges, ongoing advancements in analytical techniques coupled with effective sampling and extraction strategies offer the potential to enhance safety measures. These developments aim to minimize consumer exposure to PAs and safeguard their health while addressing the growing demand for natural alternatives in the marketplace.
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Affiliation(s)
- Bruna Tábuas
- Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal (C.C.)
| | - Sílvia Cruz Barros
- National Institute for Agricultural and Veterinary Research (INIAV), I.P, 4485-655 Vila do Conde, Portugal
| | - Catarina Diogo
- Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal (C.C.)
| | - Carlos Cavaleiro
- Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal (C.C.)
- Chemical Process Engineering and Forest Products Research Centre (CIEPQPF), University of Coimbra, Rua Sílvio Lima, 3030-790 Coimbra, Portugal
| | - Ana Sanches Silva
- Faculty of Pharmacy, University of Coimbra, Polo III, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal (C.C.)
- Center for Study in Animal Science (CECA), Institute of Sciences, Technologies and Agro-Environment of the University of Porto (ICETA), University of Porto, 4501-401 Porto, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 1300-477 Lisbon, Portugal
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Liu S, Costa M. The role of NUPR1 in response to stress and cancer development. Toxicol Appl Pharmacol 2022; 454:116244. [PMID: 36116561 DOI: 10.1016/j.taap.2022.116244] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/26/2022] [Accepted: 09/09/2022] [Indexed: 10/31/2022]
Abstract
Stress contributes to the development of many human diseases, including cancer. Based on the source of stress, it can be divided into external stress, such as environmental carcinogens, chemicals, and radiation, and internal stress, like endoplasmic reticulum (ER) stress, hypoxia, and oxidative stress. Nuclear Protein 1 (NUPR1, p8 or Com-1) is a small, highly basic transcriptional regulator that participates in regulating a variety of cellular processes including DNA repair, ER stress, oxidative stress response, cell cycle, autophagy, apoptosis, ferroptosis and chromatin remodeling. A large number of studies have reported that NUPR1 expression can be stimulated rapidly in response to various stresses. Thus, NUPR1 is also known as a stress-response gene. Since the role of NUPR1 in breast cancer was identified in 1999, an increasing number of studies sought to reveal its function in cancer. High expression of NUPR1 has been identified in oral squamous cell carcinoma, breast cancer, lung cancer, multiple myeloma, liver cancer and renal cancer. In this review, we summarize current studies of NUPR1 in response to multiple external stressors and internal stressors, and its role in mediating stressors to cause different cell signaling responses. In addition, this review discusses the function of NUPR1 in carcinogenesis, tumorigenesis, metastasis, and cancer therapy. Thus, this review gives a comprehensive insight into the role of NUPR1 in mediating signals from stress to different cell responses, and this process plays a role in the development of cancer.
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Affiliation(s)
- Shan Liu
- Division of Environmental Medicine, Dept of Medicine, New York University School of Medicine, NY, USA.
| | - Max Costa
- Division of Environmental Medicine, Dept of Medicine, New York University School of Medicine, NY, USA.
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Enge AM, Sprenger H, Braeuning A, Hessel-Pras S. Identification of microRNAs Implicated in Modulating Senecionine-Induced Liver Toxicity in HepaRG Cells. Foods 2022; 11:foods11040532. [PMID: 35206009 PMCID: PMC8871147 DOI: 10.3390/foods11040532] [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: 01/18/2022] [Revised: 02/04/2022] [Accepted: 02/08/2022] [Indexed: 12/14/2022] Open
Abstract
1,2-unsaturated Pyrrolizidine Alkaloids (PAs) are secondary plant metabolites that occur as food contaminants. Upon consumption, they can cause severe liver damage. PAs have been shown to induce apoptosis, to have cytotoxic and genotoxic effects, and to impair bile acid homeostasis in the human hepatoma cell line HepaRG. The major mode of action of PAs is DNA- and protein-adduct formation. Beyond that, nuclear receptor activation has only been observed for one receptor and two PAs, yielding the possibility that other cellular mediators are involved in PA-mediated toxicity. Here, the mode of action of Senecionine (Sc), a prominent and ubiquitous representative of hepatotoxic PAs, was investigated by analyzing 7 hepatic microRNAs (miRNAs) in HepaRG cells. Ultimately, 11 target genes that were predicted with Ingenuity Pathway Analysis software (IPA) were found to be significantly downregulated, while their assigned miRNAs showed significant upregulation of gene expression. According to IPA, these targets are positively correlated with apoptosis and cellular death and are involved in diseases such as hepatocellular carcinoma. Subsequent antagomiR-inhibition analysis revealed a significant correlation between PA-induced miRNA-4434 induction and P21-Activated Kinase-1 (PAK1) downregulation. PAK1 downregulation is usually associated with cell cycle arrest, suggesting a new function of Sc-mediated toxicity in human liver cells.
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Song J, Qiu H, Du P, Mou F, Nie Z, Zheng Y, Wang M. Polyphenols extracted from Shanxi-aged vinegar exert hypolipidemic effects on OA-induced HepG2 cells via the PPARα-LXRα-ABCA1 pathway. J Food Biochem 2022; 46:e14029. [PMID: 35023169 DOI: 10.1111/jfbc.14029] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/11/2021] [Accepted: 11/09/2021] [Indexed: 11/29/2022]
Abstract
Hyperlipidemia is one of the key risk factors causing many chronic diseases, and lowering blood lipid levels can prevent many diseases. In this paper, a hyperlipidemic cell model of oleic acid (OA) induced hepatocellular carcinoma cells (HepG2) was established using polyphenols extracted from Shanxi-aged vinegar (SAVEP). The effects of SAVEP on nuclear damage, mitochondrial membrane potential, apoptosis, cellular lipid deposition, and lipid metabolism protein expression in HepG2 hyperlipidemic cells were examined to investigate the lipid-lowering mechanism of SAVEP at the cellular level. The results showed that SAVEP could reduce the content of TC/TG index, repair the nuclear damage, reduce lipid accumulation and finally decrease the rate of apoptosis by up-regulating the expression of key proteins such as PPARα, LXRα, and ABCA1 in the process of lipid metabolism. PRACTICAL APPLICATIONS: In this thesis, the hypolipidemic activity of polyphenol extracts from Shanxi-aged vinegar was analyzed on the level of HepG2 cells. The hypolipidemic mechanism of oxidative stress, lipid metabolism and inflammatory stress was also elucidated. It provided a theoretical basis for the in-depth understanding of the hypolipidemic health effects of Shanxi-aged vinegar.
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Affiliation(s)
- Jia Song
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Huirui Qiu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Peng Du
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Fangming Mou
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Zhiqiang Nie
- Key Laboratory of Chemical Biology and Molecular Engineering, Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, China
| | - Yu Zheng
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
| | - Min Wang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, State Key Laboratory of Food Nutrition and Safety, College of Biotechnology, Tianjin University of Science & Technology, Tianjin, China
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Wang J, Wei B, Thakur K, Wang CY, Li KX, Wei ZJ. Transcriptome Analysis Reveals the Anti-cancerous Mechanism of Licochalcone A on Human Hepatoma Cell HepG2. Front Nutr 2022; 8:807574. [PMID: 34988109 PMCID: PMC8720858 DOI: 10.3389/fnut.2021.807574] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 11/30/2021] [Indexed: 12/11/2022] Open
Abstract
Hepatocellular carcinoma is a malignancy with a low survival rate globally, and there is imperative to unearth novel natural phytochemicals as effective therapeutic strategies. Licochalcone A is a chalcone from Glycyrrhiza that displayed various pharmacological efficacy. A globally transcriptome analysis was carried out to reveal the gene expression profiling to explore Licochalcone A's function as an anti-cancer phytochemical on HepG2 cells and investigate its potential mechanisms. Altogether, 6,061 dysregulated genes were detected (3,414 up-regulated and 2,647 down-regulated). SP1 was expected as the transcription factor that regulates the functions of most screened genes. GO and KEGG analysis was conducted, and the MAPK signaling pathway and the FoxO signaling pathway were two critical signal pathways. Protein-protein interaction (PPI) network analysis based on STRING platform to discover the hub genes (MAPK1, ATF4, BDNF, CASP3, etc.) in the MAPK signaling pathway and (AKT3, GADD45A, IL6, CDK2, CDKN1A, etc.) the FoxO signaling pathway. The protein level of essential genes that participated in significant pathways was consistent with the transcriptome data. This study will provide an inclusive understanding of the potential anti-cancer mechanism of Licochalcone A on hepatocellular, signifying Licochalcone A as a promising candidate for cancer therapy.
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Affiliation(s)
- Jun Wang
- School of Biological Food and Environment, Hefei University, Hefei, China
| | - Bo Wei
- School of Biological Food and Environment, Hefei University, Hefei, China
| | - Kiran Thakur
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, China.,School of Biological Science and Engineering, North Minzu University, Yinchuan, China
| | - Chu-Yan Wang
- School of Biological Food and Environment, Hefei University, Hefei, China
| | - Ke-Xin Li
- School of Biological Food and Environment, Hefei University, Hefei, China
| | - Zhao-Jun Wei
- School of Food and Biological Engineering, Hefei University of Technology, Hefei, China.,School of Biological Science and Engineering, North Minzu University, Yinchuan, China
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The Food Contaminants Pyrrolizidine Alkaloids Disturb Bile Acid Homeostasis Structure-Dependently in the Human Hepatoma Cell Line HepaRG. Foods 2021; 10:foods10051114. [PMID: 34069968 PMCID: PMC8157858 DOI: 10.3390/foods10051114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 11/18/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) are a group of secondary plant metabolites being contained in various plant species. The consumption of contaminated food can lead to acute intoxications in humans and exert severe hepatotoxicity. The development of jaundice and elevated bile acid concentrations in blood have been reported in acute human PA intoxication, indicating a connection between PA exposure and the induction of cholestasis. Additionally, it is considered that differences in toxicity of individual PAs is based on their individual chemical structures. Therefore, we aimed to elucidate the structure-dependent disturbance of bile acid homeostasis by PAs in the human hepatoma cell line HepaRG. A set of 14 different PAs, including representatives of all major structural characteristics, namely, the four different necine bases retronecine, heliotridine, otonecine and platynecine and different grades of esterification, was analyzed in regard to the expression of genes involved in bile acid synthesis, metabolism and transport. Additionally, intra- and extracellular bile acid levels were analyzed after PA treatment. In summary, our data show significant structure-dependent effects of PAs on bile acid homeostasis. Especially PAs of diester type caused the strongest dysregulation of expression of genes associated with cholestasis and led to a strong decrease of intra- and extracellular bile acid concentrations.
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He Y, Zhu L, Ma J, Lin G. Metabolism-mediated cytotoxicity and genotoxicity of pyrrolizidine alkaloids. Arch Toxicol 2021; 95:1917-1942. [PMID: 34003343 DOI: 10.1007/s00204-021-03060-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/21/2021] [Indexed: 02/06/2023]
Abstract
Pyrrolizidine alkaloids (PAs) and PA N-oxides are common phytotoxins produced by over 6000 plant species. Humans are frequently exposed to PAs via ingestion of PA-containing herbal products or PA-contaminated foods. PAs require metabolic activation to form pyrrole-protein adducts and pyrrole-DNA adducts which lead to cytotoxicity and genotoxicity. Individual PAs differ in their metabolic activation patterns, which may cause significant difference in toxic potency of different PAs. This review discusses the current knowledge and recent advances of metabolic pathways of different PAs, especially the metabolic activation and metabolism-mediated cytotoxicity and genotoxicity, and the risk evaluation methods of PA exposure. In addition, this review provides perspectives of precision toxicity assessment strategies and biomarker development for the risk control and translational investigations of human intoxication by PAs.
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Affiliation(s)
- Yisheng He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Lin Zhu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China.
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Pyrrolizidine alkaloids cause cell cycle and DNA damage repair defects as analyzed by transcriptomics in cytochrome P450 3A4-overexpressing HepG2 clone 9 cells. Cell Biol Toxicol 2021; 38:325-345. [PMID: 33884520 PMCID: PMC8986750 DOI: 10.1007/s10565-021-09599-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/02/2021] [Indexed: 10/26/2022]
Abstract
Pyrrolizidine alkaloids (PAs) are a large group of highly toxic chemical compounds, which are found as cross-contaminants in numerous food products (e.g., honey), dietary supplements, herbal teas, and pharmaceutical herbal medicines. PA contaminations are responsible for serious hepatotoxicity and hepatocarcinogenesis. Health authorities have to set legal limit values to guarantee the safe consumption of plant-based nutritional and medical products without harmful health. Toxicological and chemical analytical methods are conventionally applied to determine legally permitted limit values for PAs. In the present investigation, we applied a highly sensitive transcriptomic approach to investigate the effect of low concentrations of five PAs (lasiocarpine, riddelliine, lycopsamine, echimidine, and monocrotaline) on human cytochrome P450 3A4-overexpressing HepG2 clone 9 hepatocytes. The transcriptomic profiling of deregulated gene expression indicated that the PAs disrupted important signaling pathways related to cell cycle regulation and DNA damage repair in the transfected hepatocytes, which may explain the carcinogenic PA effects. As PAs affected the expression of genes that involved in cell cycle regulation, we applied flow cytometric cell cycle analyses to verify the transcriptomic data. Interestingly, PA treatment led to an arrest in the S phase of the cell cycle, and this effect was more pronounced with more toxic PAs (i.e., lasiocarpine and riddelliine) than with the less toxic monocrotaline. Using immunofluorescence, high fractions of cells were detected with chromosome congression defects upon PA treatment, indicating mitotic failure. In conclusion, the tested PAs revealed threshold concentrations, above which crucial signaling pathways were deregulated resulting in cell damage and carcinogenesis. Cell cycle arrest and DNA damage repair point to the mutagenicity of PAs. The disturbance of chromosome congression is a novel mechanism of Pas, which may also contribute to PA-mediated carcinogenesis. Transcriptomic, cell cycle, and immunofluorescence analyses should supplement the standard techniques in toxicology to unravel the biological effects of PA exposure in liver cells as the primary target during metabolization of PAs.
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Hama JR, Strobel BW. Occurrence of pyrrolizidine alkaloids in ragwort plants, soils and surface waters at the field scale in grassland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:142822. [PMID: 33348479 DOI: 10.1016/j.scitotenv.2020.142822] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/29/2020] [Accepted: 09/30/2020] [Indexed: 06/12/2023]
Abstract
Pyrrolizidine alkaloids (PA)s are natural toxins produced by a variety of plants including ragwort. The PAs present a serious health risk to human and livestock. Although these compounds have been extensively studied in food and feed, little is known regarding their environmental fate. To fill this data gap, we investigated the occurrence of PAs in ragwort plants, soils and surface waters at three locations where ragwort was the dominant plant species to better understand their environmental distribution. The concentrations of PAs were quantified during the full growing season (April-November) and assessed in relation to rain events. PA concentrations ranged from 3.2-6.6 g/kg dry weight (dw) in plants, 0.8-4.0 mg/kg dw in soils, and 6.0-529 μg/L in surface waters. Maximum PA concentrations in the soil (4 mg/kg) and water (529 μg/L) were in mid-May just before flowering. The average distribution of PAs in water was approximately 5 g/10,000 L, compared to the average amounts present in ragwort (506 kg/ha), and soil (1.7 kg/ha). In general, concentrations of PAs increase in the soil and surface water following rain events.
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Affiliation(s)
- 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
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Waizenegger J, Glück J, Henricsson M, Luckert C, Braeuning A, Hessel-Pras S. Pyrrolizidine Alkaloids Disturb Bile Acid Homeostasis in the Human Hepatoma Cell Line HepaRG. Foods 2021; 10:foods10010161. [PMID: 33466663 PMCID: PMC7828834 DOI: 10.3390/foods10010161] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/06/2021] [Accepted: 01/11/2021] [Indexed: 12/28/2022] Open
Abstract
1,2-unsaturated pyrrolizidine alkaloids (PAs) belong to a group of secondary plant metabolites. Exposure to PA-contaminated feed and food may cause severe hepatotoxicity. A pathway possibly involved in PA toxicity is the disturbance of bile acid homeostasis. Therefore, in this study, the influence of four structurally different PAs on bile acid homeostasis was investigated after single (24 h) and repeated (14 days) exposure using the human hepatoma cell line HepaRG. PAs induce a downregulation of gene expression of various hepatobiliary transporters, enzymes involved in bile acid synthesis, and conjugation, as well as several transcription regulators in HepaRG cells. This repression may lead to a progressive impairment of bile acid homeostasis, having the potential to accumulate toxic bile acids. However, a significant intracellular and extracellular decrease in bile acids was determined, pointing to an overall inhibition of bile acid synthesis and transport. In summary, our data clearly show that PAs structure-dependently impair bile acid homeostasis and secretion by inhibiting the expression of relevant genes involved in bile acid homeostasis. Furthermore, important biliary efflux mechanisms seem to be disturbed due to PA exposure. These mole-cular mechanisms may play an important role in the development of severe liver damage in PA-intoxicated humans.
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Affiliation(s)
- Julia Waizenegger
- Department of Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany; (J.W.); (J.G.); (C.L.); (A.B.)
- German Nutrition Society, Godesberger Allee 18, 53175 Bonn, Germany
| | - Josephin Glück
- Department of Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany; (J.W.); (J.G.); (C.L.); (A.B.)
| | - Marcus Henricsson
- Wallenberg Laboratory and Sahlgrenska Center for Cardiovascular and Metabolic Research, Institute of Medicine, University of Gothenburg, 413 45 Gothenburg, Sweden;
| | - Claudia Luckert
- Department of Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany; (J.W.); (J.G.); (C.L.); (A.B.)
| | - Albert Braeuning
- Department of Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany; (J.W.); (J.G.); (C.L.); (A.B.)
| | - Stefanie Hessel-Pras
- Department of Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany; (J.W.); (J.G.); (C.L.); (A.B.)
- Correspondence: ; Tel.: +49-30-18412-25203
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Pyrrolizidine Alkaloids Induce Cell Death in Human HepaRG Cells in a Structure-Dependent Manner. Int J Mol Sci 2020; 22:ijms22010202. [PMID: 33379168 PMCID: PMC7795836 DOI: 10.3390/ijms22010202] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 12/22/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) are a group of secondary metabolites produced in various plant species as a defense mechanism against herbivores. PAs consist of a necine base, which is esterified with one or two necine acids. Humans are exposed to PAs by consumption of contaminated food. PA intoxication in humans causes acute and chronic hepatotoxicity. It is considered that enzymatic PA toxification in hepatocytes is structure-dependent. In this study, we aimed to elucidate the induction of PA-induced cell death associated with apoptosis activation. Therefore, 22 structurally different PAs were analyzed concerning the disturbance of cell viability in the metabolically competent human hepatoma cell line HepaRG. The chosen PAs represent the main necine base structures and the different esterification types. Open-chained and cyclic heliotridine- and retronecine-type diesters induced strong cytotoxic effects, while treatment of HepaRG with monoesters did not affect cell viability. For more detailed investigation of apoptosis induction, comprising caspase activation and gene expression analysis, 14 PA representatives were selected. The proapoptotic effects were in line with the potency observed in cell viability studies. In vitro data point towards a strong structure–activity relationship whose effectiveness needs to be investigated in vivo and can then be the basis for a structure-associated risk assessment.
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Manthorpe EM, Jerrett IV, Rawlin GT, Woolford L. Plant and Fungal Hepatotoxicities of Cattle in Australia, with a Focus on Minimally Understood Toxins. Toxins (Basel) 2020; 12:E707. [PMID: 33171661 PMCID: PMC7695254 DOI: 10.3390/toxins12110707] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 01/27/2023] Open
Abstract
Plant- and fungus-derived hepatotoxins are a major cause of disease and production losses in ruminants in Australia and around the world. Many are well studied and described in the literature; however, this is not the case for a number of hepatotoxicities with economic and animal welfare impacts, such as acute bovine liver disease (ABLD), brassica-associated liver disease (BALD) and Trema tomentosa, Argentipallium blandowskianum and Lythrum hyssopifolia toxicity. Additionally, significant overlap in the clinical presentation and pathology of these conditions can present a diagnostic challenge for veterinarians. This review summarizes the current and most recently published knowledge of common plant- and fungus-associated hepatotoxins affecting cattle in Australia, with a focus on the mechanisms of toxicity and distinguishing diagnostic features. Consolidation of the current understanding of hepatotoxic mechanisms in cattle provides insight into the potential mechanisms of lesser-known toxins, including cellular and subcellular targets and potential metabolic pathways. In the absence of specific etiological investigations, the study of epidemiological, clinical and pathological features of hepatotoxicity provides valuable insights into potential toxic mechanisms and is integral for the successful diagnosis and management of these conditions.
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Affiliation(s)
- Eve M. Manthorpe
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia 5371, Australia;
| | - Ian V. Jerrett
- Department of Jobs, Precincts and Regions, Agribio, the Centre for AgriBioscience, Melbourne, Victoria 3083, Australia; (I.V.J.); (G.T.R.)
| | - Grant T. Rawlin
- Department of Jobs, Precincts and Regions, Agribio, the Centre for AgriBioscience, Melbourne, Victoria 3083, Australia; (I.V.J.); (G.T.R.)
| | - Lucy Woolford
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia 5371, Australia;
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14
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Brugnerotto P, Seraglio SKT, Schulz M, Gonzaga LV, Fett R, Costa ACO. Pyrrolizidine alkaloids and beehive products: A review. Food Chem 2020; 342:128384. [PMID: 33214040 DOI: 10.1016/j.foodchem.2020.128384] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 09/25/2020] [Accepted: 10/10/2020] [Indexed: 12/31/2022]
Abstract
Pyrrolizidine alkaloids (PA) are secondary metabolites of plants, which are mostly found in the genus Senecio, Echium, Crotalaria, and Eupatorium. The presence of 1,2-unsaturated PA in foods is a concern to food regulators around the world because these compounds have been associated to acute and chronic toxicity, mainly in the liver. The intake foods with PA/PANO usually occur through accidental ingestion of plants and their derivatives, besides to products of vegetal-animal origin, such as honey. PA/PANO are transferred to honey by their presence in nectar, honeydew, and pollen, which are collected from the flora by bees. In addition to honey, other beekeeping products, such as pollen, royal jelly, propolis, and beeswax, are also vulnerable to PA contamination. In this context, this review provides information about chemical characteristics, regulation, and toxicity, as well as summarizes and critically discusses scientific publications that evaluated PA in honeys, pollens, royal jelly, and propolis.
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Affiliation(s)
- Patricia Brugnerotto
- Department of Food Science and Technology, Federal University of Santa Catarina, Florianopolis, SC, Brazil.
| | | | - Mayara Schulz
- Department of Food Science and Technology, Federal University of Santa Catarina, Florianopolis, SC, Brazil
| | - Luciano Valdemiro Gonzaga
- Department of Food Science and Technology, Federal University of Santa Catarina, Florianopolis, SC, Brazil
| | - Roseane Fett
- Department of Food Science and Technology, Federal University of Santa Catarina, Florianopolis, SC, Brazil
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15
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Ebmeyer J, Rasinger JD, Hengstler JG, Schaudien D, Creutzenberg O, Lampen A, Braeuning A, Hessel-Pras S. Hepatotoxic pyrrolizidine alkaloids induce DNA damage response in rat liver in a 28-day feeding study. Arch Toxicol 2020; 94:1739-1751. [PMID: 32419051 PMCID: PMC7261731 DOI: 10.1007/s00204-020-02779-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/05/2020] [Indexed: 11/29/2022]
Abstract
Pyrrolizidine alkaloids (PA) are secondary plant metabolites that occur as food and feed contaminants. Acute and subacute PA poisoning can lead to severe liver damage in humans and animals, comprising liver pain, hepatomegaly and the development of ascites due to occlusion of the hepatic sinusoids (veno-occlusive disease). Chronic exposure to low levels of PA can induce liver cirrhosis and liver cancer. However, it is not well understood which transcriptional changes are induced by PA and whether all hepatotoxic PA, regardless of their structure, induce similar responses. Therefore, a 28-day subacute rat feeding study was performed with six structurally different PA heliotrine, echimidine, lasiocarpine, senecionine, senkirkine, and platyphylline, administered at not acutely toxic doses from 0.1 to 3.3 mg/kg body weight. This dose range is relevant for humans, since consumption of contaminated tea may result in doses of ~ 8 µg/kg in adults and cases of PA ingestion by contaminated food was reported for infants with doses up to 3 mg/kg body weight. ALT and AST were not increased in all treatment groups. Whole-genome microarray analyses revealed pronounced effects on gene expression in the high-dose treatment groups resulting in a set of 36 commonly regulated genes. However, platyphylline, the only 1,2-saturated and, therefore, presumably non-hepatotoxic PA, did not induce significant expression changes. Biological functions identified to be affected by high-dose treatments (3.3 mg/kg body weight) comprise cell-cycle regulation associated with DNA damage response. These functions were found to be affected by all analyzed 1,2-unsaturated PA. In conclusion, 1,2-unsaturated hepatotoxic PA induced cell cycle regulation processes associated with DNA damage response. Similar effects were observed for all hepatotoxic PA. Effects were observed in a dose range inducing no histopathological alterations and no increase in liver enzymes. Therefore, transcriptomics studies identified changes in expression of genes known to be involved in response to genotoxic compounds at PA doses relevant to humans under worst case exposure scenarios.
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Affiliation(s)
- Johanna Ebmeyer
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | | | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Dirk Schaudien
- Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, Nikolai-Fuchs-Straße 1, 30625, Hanover, Germany
| | - Otto Creutzenberg
- Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, Nikolai-Fuchs-Straße 1, 30625, Hanover, Germany
| | - Alfonso Lampen
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Albert Braeuning
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Stefanie Hessel-Pras
- German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany.
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16
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Hessel-Pras S, Braeuning A, Guenther G, Adawy A, Enge AM, Ebmeyer J, Henderson CJ, Hengstler JG, Lampen A, Reif R. The pyrrolizidine alkaloid senecionine induces CYP-dependent destruction of sinusoidal endothelial cells and cholestasis in mice. Arch Toxicol 2020; 94:219-229. [PMID: 31606820 DOI: 10.1007/s00204-019-02582-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/18/2019] [Indexed: 02/07/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are widely occurring phytotoxins which can induce severe liver damage in humans and other mammalian species by mechanisms that are not fully understood. Therefore, we investigated the development of PA hepatotoxicity in vivo, using an acutely toxic dose of the PA senecionine in mice, in combination with intravital two-photon microscopy, histology, clinical chemistry, and in vitro experiments with primary mouse hepatocytes and liver sinusoidal endothelial cells (LSECs). We observed pericentral LSEC necrosis together with elevated sinusoidal marker proteins in the serum of senecionine-treated mice and increased sinusoidal platelet aggregation in the damaged tissue regions. In vitro experiments showed no cytotoxicity to freshly isolated LSECs up to 500 µM senecionine. However, metabolic activation of senecionine by preincubation with primary mouse hepatocytes increased the cytotoxicity to cultivated LSECs with an EC50 of approximately 22 µM. The cytochrome P450 (CYP)-dependency of senecionine bioactivation was confirmed in CYP reductase-deficient mice where no PA-induced hepatotoxicity was observed. Therefore, toxic metabolites of senecionine are generated by hepatic CYPs, and may be partially released from hepatocytes leading to destruction of LSECs in the pericentral region of the liver lobules. Analysis of hepatic bile salt transport by intravital two-photon imaging revealed a delayed uptake of a fluorescent bile salt analogue from the hepatic sinusoids into hepatocytes and delayed elimination. This was accompanied by transcriptional deregulation of hepatic bile salt transporters like Abcb11 or Abcc1. In conclusion, senecionine destroys LSECs although the toxic metabolite is formed in a CYP-dependent manner in the adjacent pericentral hepatocytes.
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Affiliation(s)
- Stefanie Hessel-Pras
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, Berlin, Germany.
| | - Albert Braeuning
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, Berlin, Germany
| | - Georgia Guenther
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystraße 67, Dortmund, Germany
| | - Alshaimaa Adawy
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystraße 67, Dortmund, Germany
| | - Anne-Margarethe Enge
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, Berlin, Germany
| | - Johanna Ebmeyer
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, Berlin, Germany
| | - Colin J Henderson
- Systems Medicine, Jacqui Wood Cancer Centre, University of Dundee, School of Medicine, James Arrott Drive, Ninewells Hospital, Dundee, UK
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystraße 67, Dortmund, Germany
| | - Alfonso Lampen
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, Berlin, Germany
| | - Raymond Reif
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystraße 67, Dortmund, Germany
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17
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Kreuzer K, Frenzel F, Lampen A, Braeuning A, Böhmert L. Transcriptomic effect marker patterns of genotoxins - a comparative study with literature data. J Appl Toxicol 2019; 40:448-457. [PMID: 31845381 DOI: 10.1002/jat.3928] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 10/29/2019] [Accepted: 11/03/2019] [Indexed: 01/19/2023]
Abstract
Microarray approaches are frequently used experimental tools which have proven their value for example in the characterization of the molecular mode of action of toxicologically relevant compounds. In a regulatory context, omics techniques are still not routinely used, amongst others due to lacking standardization in experimental setup and data processing, and also due to issues with the definition of adversity. In order to exemplarily determine whether consensus transcript biomarker signatures for a certain toxicological endpoint can be derived from published microarray datasets, we here compared transcriptome data from human HepaRG hepatocarcinoma cells treated with different genotoxins, based on re-analyzed datasets extracted from the literature. Comparison of the resulting data show that even with similarly-acting compounds in the same cell line, considerable variation was observed with respect to the numbers and identities of differentially expressed genes. Greater concordance was observed when considering the whole data sets and biological functions associated with the genes affected. The present results highlight difficulties and possibilities in inter-experiment comparisons of omics data and underpin the need for future efforts towards improved standardization to facilitate the use of omics data in risk assessment. Existing omics datasets may nonetheless prove valuable in establishing biological context information essential for the development of adverse outcome pathways.
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Affiliation(s)
- Katrin Kreuzer
- Dept. Food Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Falko Frenzel
- Dept. Food Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Alfonso Lampen
- Dept. Food Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Albert Braeuning
- Dept. Food Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Linda Böhmert
- Dept. Food Safety, German Federal Institute for Risk Assessment, Berlin, Germany
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18
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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]
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19
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An important mechanism of herb-induced hepatotoxicity: To produce RMs based on active functional groups-containing ingredients from phytomedicine by binding CYP450s. CHINESE HERBAL MEDICINES 2019. [DOI: 10.1016/j.chmed.2019.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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20
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Ebmeyer J, Franz L, Lim R, Niemann B, Glatt H, Braeuning A, Lampen A, Hessel-Pras S. Sensitization of Human Liver Cells Toward Fas-Mediated Apoptosis by the Metabolically Activated Pyrrolizidine Alkaloid Lasiocarpine. Mol Nutr Food Res 2019; 63:e1801206. [PMID: 30900802 DOI: 10.1002/mnfr.201801206] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 03/18/2019] [Indexed: 12/16/2022]
Abstract
SCOPE Pyrrolizidine alkaloids (PAs) are common phytotoxins. Intoxication can lead to liver damage. Previous studies showed PA-induced apoptosis in liver cells. However, the exact role of the extrinsic apoptotic pathway has not been investigated yet. This study aims to analyze whether the PA representative lasiocarpine sensitizes human liver cells toward extrinsic Fas-mediated apoptosis. METHODS AND RESULTS HepG2 cells with limited xenobiotic metabolic activity are used to analyze metabolism-dependent effects. External in vitro metabolism is simulated using rat or human liver enzymes. Additionally, metabolically competent HepaRG cells are used to confirm the observed effects in a human liver cell system with internal xenobiotic metabolism. Metabolized lasiocarpine decreases cell viability and induces Fas receptor gene expression in both cell lines. Increased Fas receptor protein expression on the cell surface is demonstrated by flow cytometry. The addition of a Fas ligand-simulating antibody induces apoptosis. Induction of extrinsic Fas-mediated apoptosis is verified by Western blotting for cleaved caspase 8, the initiator caspase of extrinsic apoptosis. All effects are dependent on lasiocarpine metabolism. CONCLUSION The results demonstrate that metabolically metabolized lasiocarpine sensitizes human liver cells toward Fas-mediated apoptosis. They broaden our knowledge on the hepatotoxic molecular mechanisms of PA as widely distributed food contaminants.
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Affiliation(s)
- Johanna Ebmeyer
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Luise Franz
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Ramonique Lim
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Birgit Niemann
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Hansruedi Glatt
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Albert Braeuning
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Alfonso Lampen
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Stefanie Hessel-Pras
- Department Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
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21
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Macáková K, Afonso R, Saso L, Mladěnka P. The influence of alkaloids on oxidative stress and related signaling pathways. Free Radic Biol Med 2019; 134:429-444. [PMID: 30703480 DOI: 10.1016/j.freeradbiomed.2019.01.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/16/2019] [Accepted: 01/21/2019] [Indexed: 12/19/2022]
Abstract
Alkaloids have always attracted scientific interest due to either their positive or negative effects on human beings. This review aims to summarize their antioxidant effects by both classical in vitro scavenging assay and at the cellular level. Since most in vitro studies used the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay, the results from those studies are summed up in the first part of the article. In the second part, available data on the effect of alkaloids on NADPH-oxidase, the key enzyme for reactive oxygen species production, at the cellular level, are summarized. More than 130 alkaloids were tested by DPPH assay. However, due to methodological differences, a direct comparison is hardly possible. It can be at least concluded that some of them were either similar to or even more active than standard antioxidants and the number of aromatic hydroxyl groups seems to be the major determinant for the activity. The data on inhibition of NADPH-oxidase activity by alkaloids demonstrated that there is little relationship to the DPPH assay. The mechanism seems to be based on inhibition of synthesis, activation or translocation of NADPH-oxidase subunits. In some alkaloids, activation of the nuclear factor Nrf2 pathway was documented to be the grounds for inhibition of NADPH-oxidase. Interestingly, many alkaloids can behave both as anti-oxidants and pro-oxidants depending on conditions and pro-oxidation might be the reason for activation of Nrf2. Available data on other "antioxidant" transcription factors FOXOs and PPARs are also mentioned.
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Affiliation(s)
- Kateřina Macáková
- Department of Pharmaceutical Botany, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
| | - Rita Afonso
- Department of Pharmacology and Toxicology, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
| | - Luciano Saso
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Piazzale Aldo Moro 5, Rome, Italy.
| | - Přemysl Mladěnka
- Department of Pharmacology and Toxicology, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic.
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22
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Ebmeyer J, Behrend J, Lorenz M, Günther G, Reif R, Hengstler JG, Braeuning A, Lampen A, Hessel-Pras S. Pyrrolizidine alkaloid-induced alterations of prostanoid synthesis in human endothelial cells. Chem Biol Interact 2018; 298:104-111. [PMID: 30465738 DOI: 10.1016/j.cbi.2018.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/08/2018] [Accepted: 11/13/2018] [Indexed: 11/16/2022]
Abstract
Pyrrolizidine alkaloids (PA) are a group of secondary plant metabolites belonging to the most widely distributed natural toxins. PA intoxication of humans leads to severe liver damage, such as hepatomegaly, hepatic necrosis, fibrosis and cirrhosis. An acute consequence observed after ingestion of high amounts of PA is veno-occlusive disease (VOD) where the hepatic sinusoidal endothelial cells are affected. However, the mechanisms leading to VOD after PA intoxication remain predominantly unknown. Thus, we investigated PA-induced molecular effects on human umbilical vein endothelial cells (HUVEC). We compared the effects of PA with the effects of PA metabolites obtained by in vitro metabolism using liver homogenate (S9 fraction). In vitro-metabolized lasiocarpine and senecionine resulted in significant cytotoxic effects in HUVEC starting at 300 μM. Initial molecular effect screening using a PCR array with genes associated with endothelial cell biology showed PA-induced upregulation of the Fas receptor, which is involved in extrinsic apoptosis, and regulation of a number of interleukins, as well as of different enzymes relevant for prostanoid synthesis. Modulation of prostanoid synthesis was subsequently studied at the mRNA and protein levels and verified by increased release of prostaglandin I2 as the main prostanoid of endothelial cells. All effects occurred only with in vitro-metabolically activated PA lasiocarpine and senecionine. By contrast, no effect was observed for the PA echimidine, heliotrine, lasiocarpine, senecionine, senkirkine and platyphylline in the absence of an external metabolizing system up to the highest tested concentration of 500 μM. Overall, our results confirm the metabolism-dependent toxification of PA and elucidate the involved pathways. These include induction of inflammatory cytokines and deregulation of the prostanoid synthesis pathway in endothelial cells, linking for the first time PA-dependent changes in prostanoid release to distinct alterations at the mRNA and protein levels of enzymes of prostanoid synthesis.
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Affiliation(s)
- Johanna Ebmeyer
- German Federal Institute for Risk Assessment, Department Food Safety, Berlin, Germany
| | - Jessica Behrend
- German Federal Institute for Risk Assessment, Department Food Safety, Berlin, Germany
| | - Mario Lorenz
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Medizinische Klinik für Kardiologie und Angiologie, Campus Mitte, Berlin, Germany
| | - Georgia Günther
- Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
| | - Raymond Reif
- Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany
| | - Albert Braeuning
- German Federal Institute for Risk Assessment, Department Food Safety, Berlin, Germany
| | - Alfonso Lampen
- German Federal Institute for Risk Assessment, Department Food Safety, Berlin, Germany
| | - Stefanie Hessel-Pras
- German Federal Institute for Risk Assessment, Department Food Safety, Berlin, Germany.
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23
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Liu Y. Incorporation of absorption and metabolism into liver toxicity prediction for phytochemicals: A tiered in silico QSAR approach. Food Chem Toxicol 2018; 118:409-415. [DOI: 10.1016/j.fct.2018.05.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 04/05/2018] [Accepted: 05/16/2018] [Indexed: 02/06/2023]
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24
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Moreira R, Pereira DM, Valentão P, Andrade PB. Pyrrolizidine Alkaloids: Chemistry, Pharmacology, Toxicology and Food Safety. Int J Mol Sci 2018; 19:E1668. [PMID: 29874826 PMCID: PMC6032134 DOI: 10.3390/ijms19061668] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/23/2018] [Accepted: 05/23/2018] [Indexed: 12/25/2022] Open
Abstract
Pyrrolizidine alkaloids (PA) are widely distributed in plants throughout the world, frequently in species relevant for human consumption. Apart from the toxicity that these molecules can cause in humans and livestock, PA are also known for their wide range of pharmacological properties, which can be exploited in drug discovery programs. In this work we review the current body of knowledge regarding the chemistry, toxicology, pharmacology and food safety of PA.
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Affiliation(s)
- Rute Moreira
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
| | - David M Pereira
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
| | - Patrícia Valentão
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
| | - Paula B Andrade
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, nº 228, 4050-313 Porto, Portugal.
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25
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PXR: Structure-specific activation by hepatotoxic pyrrolizidine alkaloids. Chem Biol Interact 2018; 288:38-48. [DOI: 10.1016/j.cbi.2018.04.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/11/2018] [Accepted: 04/13/2018] [Indexed: 01/03/2023]
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26
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Glück J, Buhrke T, Frenzel F, Braeuning A, Lampen A. In silico genotoxicity and carcinogenicity prediction for food-relevant secondary plant metabolites. Food Chem Toxicol 2018; 116:298-306. [PMID: 29660365 DOI: 10.1016/j.fct.2018.04.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/05/2018] [Accepted: 04/09/2018] [Indexed: 01/24/2023]
Abstract
Humans are exposed to thousands of different secondary plant metabolites which may have beneficial health effects, but numerous compounds may also have toxic potential. In the present study we have examined the genotoxic and carcinogenic potential of 609 food-relevant phytochemicals by using computer models for toxicity prediction. We developed a scoring method and combined the results of different models to increase the predictive power. A combination of the VEGA models SARpy, KNN, ISS, and CAESAR, and of the LAZAR model "Salmonella typhimurium" for genotoxicity prediction performed better than the single models regarding specificity and accuracy. Statistical evaluation of the combined model for carcinogenicity prediction was not possible due to the low number of substances suitable for model validation. The in silico results of the present exercise will be useful for priority setting purposes regarding future risk assessment of secondary plant metabolites. Based on our analysis, (-)-asimilobine, aloin, annoretine, chrysothrone, coptisine, elymoclavine, and thalicminine were predicted to be genotoxic with high probability and may therefore be selected for subsequent experimental genotoxicity testing. Moreover, the class of pyrrolizidine alkaloids is suggested to be a high priority subject for further studies as these substances have been predicted to be carcinogenic with high probability.
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Affiliation(s)
- Josephin Glück
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Thorsten Buhrke
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
| | - Falko Frenzel
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Albert Braeuning
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Alfonso Lampen
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
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Waizenegger J, Braeuning A, Templin M, Lampen A, Hessel-Pras S. Structure-dependent induction of apoptosis by hepatotoxic pyrrolizidine alkaloids in the human hepatoma cell line HepaRG: Single versus repeated exposure. Food Chem Toxicol 2018; 114:215-226. [PMID: 29458164 DOI: 10.1016/j.fct.2018.02.036] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/12/2018] [Accepted: 02/15/2018] [Indexed: 11/28/2022]
Abstract
Pyrrolizidine alkaloids (PA) are secondary plant compounds. PA intoxication in humans causes severe acute and chronic hepatotoxicity. However, the molecular mechanisms of PA hepatotoxicity in humans are not well understood yet. Therefore, we investigated cell death parameters in human HepaRG cells following either single (24 h) or repeated dose treatment (14 d) with structurally different PA of the retronecine (echimidine, senecionine), heliotridine (heliotrine), and otonecine type (senkirkine). After 24 h of exposure only retronecine-type PA were cytotoxic in HepaRG cells and induced apoptosis indicated by a loss of membrane asymmetry, disruption of the mitochondrial membrane potential, and increased pro-caspase and PARP cleavage. In contrast, after 14 d all four PA exerted the aforementioned effects. Furthermore, the apoptotic events caspase 3, 8 and 9 activation as well as nuclear condensation and DNA fragmentation were only detected for the retronecine-type PA after single exposure (6 h). Overall, our studies revealed a time- and structure-dependent apoptosis after PA exposure, suggesting that retronecine-type PA seem to be more potent apoptosis inducers than heliotridine- or otonecine-type PA. Furthermore, our results suggest that PA-induced apoptosis in HepaRG cells occur most probably by involving both, the extrinsic death receptor pathway as well as the intrinsic mitochondrial pathway.
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Affiliation(s)
- Julia Waizenegger
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany
| | - Albert Braeuning
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany
| | - Markus Templin
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Markwiesenstraße 55, 72770 Reutlingen, Germany
| | - Alfonso Lampen
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany
| | - Stefanie Hessel-Pras
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany.
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28
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Habs M, Binder K, Krauss S, Müller K, Ernst B, Valentini L, Koller M. A Balanced Risk-Benefit Analysis to Determine Human Risks Associated with Pyrrolizidine Alkaloids (PA)-The Case of Tea and Herbal Infusions. Nutrients 2017; 9:E717. [PMID: 28686224 PMCID: PMC5537832 DOI: 10.3390/nu9070717] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 06/28/2017] [Accepted: 07/03/2017] [Indexed: 12/23/2022] Open
Abstract
Humans are exposed to pyrrolizidine alkaloids (PA) through different sources, mainly from contaminated foodstuff. Teas and herbal infusions (T&HI) can be contaminated by PA producing weed. PA can possess toxic, mutagenic, genotoxic, and carcinogenic properties. Thus, possible health risks for the general population are under debate. There is a strong safety record for T&HI and additionally epidemiological evidence for the preventive effects of regular tea consumption on cardiovascular events and certain types of cancer. There is no epidemiological evidence, however, for human risks of regular low dose PA exposure. Recommended regulatory PA-threshold values are based on experimental data only, accepting big uncertainties. If a general risk exists through PA contaminated T&HI, it must be small compared to other frequently accepted risks of daily living and the proven health effects of T&HI. Decision making should be based on a balanced riskbenefit analysis. Based on analyses of the scientific data currently available, it is concluded that the benefits of drinking T&HI clearly outweigh the negligible health risk of possible PA contamination. At the same time, manufacturers must continue their efforts to secure good product quality and to be transparent on their measures of quality control and risk communication.
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Affiliation(s)
- Michael Habs
- Faculty of Medicine, LMU-University of Munich, 80333 Munich, Germany.
| | - Karin Binder
- Didactics of Mathematics, University of Regensburg, 93053 Regensburg, Germany.
| | - Stefan Krauss
- Didactics of Mathematics, University of Regensburg, 93053 Regensburg, Germany.
| | - Karolina Müller
- Centre for Clinical Studies, University Hospital Regensburg, 93042 Regensburg, Germany.
| | - Brigitte Ernst
- General Medicine Unit, University Hospital Regensburg, 93053 Regensburg, Germany.
| | - Luzia Valentini
- Institute of Evidence-based Dietetics, University of Applied Sciences Neubrandenburg, 17033 Neubrandenburg, Germany.
| | - Michael Koller
- Centre for Clinical Studies, University Hospital Regensburg, 93042 Regensburg, Germany.
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29
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Interim relative potency factors for the toxicological risk assessment of pyrrolizidine alkaloids in food and herbal medicines. Toxicol Lett 2016; 263:44-57. [PMID: 27157086 DOI: 10.1016/j.toxlet.2016.05.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/29/2016] [Accepted: 05/02/2016] [Indexed: 11/21/2022]
Abstract
Pyrrolizidine alkaloids (PAs) are among the most potent natural toxins occurring in a broad spectrum of plant species from various families. Recently, findings of considerable contamination of teas/herbal infusions prepared from non-PA plants have been reported. These are obviously due to cross-contamination with minor amounts of PA plants and can affect both food and herbal medicines. Another source of human exposure is honey collected from PA plants. These findings illustrate the requirement for a comprehensive risk assessment of PAs, hampered by the enormous number of different PA congeners occurring in nature. Up to now, risk assessment is based on the carcinogenicity of certain PAs after chronic application to rats using the sum of detected PAs as dose metric. Because of the well-documented large structure-dependent differences between sub-groups of PA congeners with respect to their genotoxicity and (cyto)toxicity, however, this procedure is inadequate. Here we provide an overview of recent attempts to assess the risk of PA exposure and the available literature on the toxic effects and potencies of different congeners. Based on these considerations, we have derived interim Relative Potency (REP) factors for a number of abundant PAs suggesting a factor of 1.0 for cyclic di-esters and open-chain di-esters with 7S configuration, of 0.3 for mono-esters with 7S configuration, of 0.1 for open-chain di-esters with 7R configuration and of 0.01 for mono-esters with 7R configuration. For N-oxides we suggest to apply the REP factor of the corresponding PA. We are confident that the use of these values can provide a more scientific basis for PA risk assessment until a more detailed experimental analysis of the potencies of all relevant congeners can be carried out.
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