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Silva AL, Oliveira JL, do Nascimento RP, Santos LO, de Araújo FM, Dos Santos BL, Santana RC, Moreira ELT, Batatinha MJM, Alves IM, Velozo ES, Victor MM, Assis AM, Almeida RF, de Souza DOG, Silva VDA, Costa SL. Monocrotaline induces acutely cerebrovascular lesions, astrogliosis and neuronal degeneration associated with behavior changes in rats: A model of vascular damage in perspective. Neurotoxicology 2023; 94:59-70. [PMID: 36336098 DOI: 10.1016/j.neuro.2022.10.017] [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: 01/19/2022] [Revised: 08/15/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022]
Abstract
Pyrrolizidine alkaloids (PAs) are secondary plant metabolites playing an important role as phytotoxins in the plant defense mechanisms and can be present as contaminant in the food of humans and animals. The PA monocrotaline (MCT), one of the major plant derived toxin that affect humans and animals, is present in a high concentration in Crotalaria spp. (Leguminosae) seeds and can induce toxicity after consumption, characterized mainly by hepatotoxicity and pneumotoxicity. However, the effects of the ingestion of MCT in the central nervous system (CNS) are still poorly elucidated. Here we investigated the effects of MCT oral acute administration on the behavior and CNS toxicity in rats. Male adult Wistar were treated with MCT (109 mg/Kg, oral gavage) and three days later the Elevated Pluz Maze test demonstrated that MCT induced an anxiolytic-like effect, without changes in novelty habituation and in operational and spatial memory profiles. Histopathology revealed that the brain of MCT-intoxicated animals presented hyperemic vascular structures in the hippocampus, parahippocampal cortex and neocortex, mild perivascular edema in the neocortex, hemorrhagic focal area in the brain stem, hemorrhage and edema in the thalamus. MCT also induced neurotoxicity in the cortex and hippocampus, as revealed by Fluoro Jade-B and Cresyl Violet staining, as well astrocyte reactivity, revealed by immunocytochemistry for glial fibrillary acidic protein. Additionally, it was demonstrated by RT-qPCR that MCT induced up-regulation on mRNA expression of neuroinflammatory mediator, especially IL1β and CCL2 in the hippocampus and cortex, and down-regulation on mRNA expression of neurotrophins HGDF and BDNF in the cortex. Together, these results demonstrate that the ingestion of MCT induces cerebrovascular lesions and toxicity to neurons that are associated to astroglial cell response and neuroinflammation in the cortex and hippocampus of rats, highlighting CNS damages after acute intoxication, also putting in perspective it uses as a model for cerebrovascular damage.
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Affiliation(s)
- Adriana L Silva
- Laboratory of Neurochemistry and Cellular Biology, Institute of Health Sciences, Federal University of Bahia, Brazil
| | - Joana L Oliveira
- Laboratory of Neurochemistry and Cellular Biology, Institute of Health Sciences, Federal University of Bahia, Brazil
| | - Ravena P do Nascimento
- Laboratory of Neurochemistry and Cellular Biology, Institute of Health Sciences, Federal University of Bahia, Brazil
| | - Letícia O Santos
- Laboratory of Neurochemistry and Cellular Biology, Institute of Health Sciences, Federal University of Bahia, Brazil
| | - Fillipe M de Araújo
- Laboratory of Neurochemistry and Cellular Biology, Institute of Health Sciences, Federal University of Bahia, Brazil
| | - Balbino L Dos Santos
- Laboratory of Neurochemistry and Cellular Biology, Institute of Health Sciences, Federal University of Bahia, Brazil; Federal University of Vale do São Francisco, Brazil
| | - Rejane C Santana
- Laboratory of Neuroscience, Federal University of Bahia, Institute of Health Sciences, Federal University of Bahia, Brazil
| | - Eduardo Luiz T Moreira
- School of Veterinary Medicine and Animal Science, Hospital of Veterinary Medicine, Department of Anatomy, Pathology and Veterinary Clinics, Federal University of Bahia, Brazil
| | - Maria José M Batatinha
- Laboratory of Toxicology, School of Veterinary Medicine and Animal Science, Hospital of Veterinary Medicine, Federal University of Bahia, Brazil
| | - Iura M Alves
- Faculty of Pharmacy, Department of Medication, Federal University of Bahia, Brazil
| | - Eudes S Velozo
- Faculty of Pharmacy, Department of Medication, Federal University of Bahia, Brazil
| | - Mauricio M Victor
- Organic Chemistry Department, Chemistry Institute, Federal University of Bahia, Brazil
| | - Adriano M Assis
- Institute of Basic Health Sciences Department of Biochemistry, Federal University of Rio Grande do Sul, Brazil; Catholic University of Pelotas, Brazil
| | - Roberto F Almeida
- Institute of Basic Health Sciences Department of Biochemistry, Federal University of Rio Grande do Sul, Brazil; Federal University of Ouro Preto, Brazil
| | - Diogo O G de Souza
- Institute of Basic Health Sciences Department of Biochemistry, Federal University of Rio Grande do Sul, Brazil; INCT for Excitotoxicity and Neuroprotection - CNPq (INCT-EN, BR), Brazil
| | - Victor Diógenes A Silva
- Laboratory of Neurochemistry and Cellular Biology, Institute of Health Sciences, Federal University of Bahia, Brazil; INCT for Excitotoxicity and Neuroprotection - CNPq (INCT-EN, BR), Brazil.
| | - Silvia L Costa
- Laboratory of Neurochemistry and Cellular Biology, Institute of Health Sciences, Federal University of Bahia, Brazil; INCT for Excitotoxicity and Neuroprotection - CNPq (INCT-EN, BR), Brazil.
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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: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/21/2021] [Indexed: 02/06/2023]
Abstract
Pyrrolizidine alkaloids (PAs) and PA N-oxides are common phytotoxins produced by over 6000 plant species. Humans are frequently exposed to PAs via ingestion of PA-containing herbal products or PA-contaminated foods. PAs require metabolic activation to form pyrrole-protein adducts and pyrrole-DNA adducts which lead to cytotoxicity and genotoxicity. Individual PAs differ in their metabolic activation patterns, which may cause significant difference in toxic potency of different PAs. This review discusses the current knowledge and recent advances of metabolic pathways of different PAs, especially the metabolic activation and metabolism-mediated cytotoxicity and genotoxicity, and the risk evaluation methods of PA exposure. In addition, this review provides perspectives of precision toxicity assessment strategies and biomarker development for the risk control and translational investigations of human intoxication by PAs.
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Affiliation(s)
- Yisheng He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Lin Zhu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China.
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Zhang Y, Yang FF, Chen H, Qi YD, Si JY, Wu Q, Liao YH. Analysis of pyrrolizidine alkaloids in Eupatorium fortunei Turcz. and their in vitro neurotoxicity. Food Chem Toxicol 2021; 151:112151. [PMID: 33774095 DOI: 10.1016/j.fct.2021.112151] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 12/11/2022]
Abstract
This study was to analyze the pyrrolizidine alkaloids (PAs) in Eupatorium fortunei herbs and its derived finished products with a view to evaluating their effects on the proliferation and oligodendrogenesis of neural progenitor cells (NPCs). Using a LC-MS/MS method with 32 PAs reference standards, 8 PAs including intermedine, intermedine N-oxide, lycopsamine, lycopsamine N-oxide, retronecine, seneciphylline and senkirkine and 7-acetylintermedine N-oxide were identified with intermedine N-oxide and lycopsamine N-oxide being most abundant. The total PA amounts were found to vary from 0.18 to 61.81 μg/g in 30 batches of herbs and from 0.86 to 36.96 μg/g in 4 commercial finished products, respectively. Risk assessments indicated that the short-term intake seemed unlikely lead to acute toxic effects but the chronic use warranted cautions. Using NPCs derived from mouse induced pluripotent stem cells as an in vitro testing model, intermedine, intermedine N-oxide and lycopsamine N-oxide appeared to decrease cell viability at 30 μM whereas intermedine N-oxide inhibited oligodendrogenesis of NPCs at 10 μM. The present results suggested that the PAs in the majority of E. fortunei herbs and the derived products not only resulted in their exposure far exceeding the acceptable intake limit (i. e. 1.0 μg PA per day for adults) in herbal medicinal products recommended by the European Medicines Agency but also induced neurotoxicity to NPCs in vitro.
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Affiliation(s)
- Yan Zhang
- Beijing University of Chinese Medicine, Yangguang South Street, Fangshan District, Beijing, 102488, PR China; Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Fei-Fei Yang
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Huan Chen
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Yao-Dong Qi
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Jian-Yong Si
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China
| | - Qing Wu
- Beijing University of Chinese Medicine, Yangguang South Street, Fangshan District, Beijing, 102488, PR China.
| | - Yong-Hong Liao
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151 Malianwa North Road, Haidian District, Beijing, 100193, PR China.
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Chen L, Ning J, Louisse J, Wesseling S, Rietjens IMCM. Use of physiologically based kinetic modelling-facilitated reverse dosimetry to convert in vitro cytotoxicity data to predicted in vivo liver toxicity of lasiocarpine and riddelliine in rat. Food Chem Toxicol 2018; 116:216-226. [PMID: 29634986 DOI: 10.1016/j.fct.2018.04.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/15/2018] [Accepted: 04/05/2018] [Indexed: 01/10/2023]
Abstract
Lasiocarpine and riddelliine are pyrrolizidine alkaloids (PAs) present in food and able to cause liver toxicity. The aim of this study was to investigate whether physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry can adequately translate in vitro concentration-response curves for toxicity of lasiocarpine and riddelliine to in vivo liver toxicity data for the rat. To this purpose, PBK models were developed for lasiocarpine and riddelliine, and predicted blood concentrations were compared to available literature data to evaluate the models. Concentration-response curves obtained from in vitro cytotoxicity assays in primary rat hepatocytes were converted to in vivo dose-response curves from which points of departure (PODs) were derived and that were compared to available literature data on in vivo liver toxicity. The results showed that the predicted PODs fall well within the range of PODs derived from available in vivo toxicity data. To conclude, this study shows the proof-of-principle for a method to predict in vivo liver toxicity for PAs by an alternative testing strategy integrating in vitro cytotoxicity assays with in silico PBK modelling-facilitated reverse dosimetry. The approach may facilitate prediction of acute liver toxicity for the large number of PAs for which in vivo toxicity data are lacking.
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Affiliation(s)
- Lu Chen
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands.
| | - Jia Ning
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands
| | - Jochem Louisse
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands
| | - Sebas Wesseling
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands
| | - Ivonne M C M Rietjens
- Division of Toxicology, Wageningen University, PO Box 8000, 6700 EA Wageningen, The Netherlands
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5
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Nascimento RP, Oliveira JL, Carvalho JLC, Santos WA, Pires TRC, Batatinha MJM, El-Bachá RS, Silva VDA, Costa SL. Involvement of astrocytic CYP1A1 isoform in the metabolism and toxicity of the alkaloid pyrrolizidine monocrotaline. Toxicon 2017; 134:41-49. [DOI: 10.1016/j.toxicon.2017.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 04/06/2017] [Accepted: 04/07/2017] [Indexed: 11/27/2022]
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6
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Sakamoto S, Nagamitsu R, Yusakul G, Miyamoto T, Tanaka H, Morimoto S. Ultrasensitive immunoassay for monocrotaline using monoclonal antibody produced by N, N’ -carbonyldiimidazole mediated hapten-carrier protein conjugates. Talanta 2017; 168:67-72. [DOI: 10.1016/j.talanta.2017.03.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 03/08/2017] [Accepted: 03/09/2017] [Indexed: 11/16/2022]
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7
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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.
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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
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8
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Luckert C, Hessel S, Lenze D, Lampen A. Disturbance of gene expression in primary human hepatocytes by hepatotoxic pyrrolizidine alkaloids: A whole genome transcriptome analysis. Toxicol In Vitro 2015; 29:1669-82. [PMID: 26100227 DOI: 10.1016/j.tiv.2015.06.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/29/2015] [Accepted: 06/19/2015] [Indexed: 11/30/2022]
Abstract
1,2-unsaturated pyrrolizidine alkaloids (PA) are plant metabolites predominantly occurring in the plant families Asteraceae and Boraginaceae. Acute and chronic PA poisoning causes severe hepatotoxicity. So far, the molecular mechanisms of PA toxicity are not well understood. To analyze its mode of action, primary human hepatocytes were exposed to a non-cytotoxic dose of 100 μM of four structurally different PA: echimidine, heliotrine, senecionine, senkirkine. Changes in mRNA expression were analyzed by a whole genome microarray. Employing cut-off values with a |fold change| of 2 and a q-value of 0.01, data analysis revealed numerous changes in gene expression. In total, 4556, 1806, 3406 and 8623 genes were regulated by echimidine, heliotrine, senecione and senkirkine, respectively. 1304 genes were identified as commonly regulated. PA affected pathways related to cell cycle regulation, cell death and cancer development. The transcription factors TP53, MYC, NFκB and NUPR1 were predicted to be activated upon PA treatment. Furthermore, gene expression data showed a considerable interference with lipid metabolism and bile acid flow. The associated transcription factors FXR, LXR, SREBF1/2, and PPARα/γ/δ were predicted to be inhibited. In conclusion, though structurally different, all four PA significantly regulated a great number of genes in common. This proposes similar molecular mechanisms, although the extent seems to differ between the analyzed PA as reflected by the potential hepatotoxicity and individual PA structure.
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Affiliation(s)
- Claudia Luckert
- Department of Food Safety, Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany; Department of Nutritional Toxicology, Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Stefanie Hessel
- Department of Food Safety, Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany.
| | - Dido Lenze
- Institute of Pathology, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12200 Berlin, Germany
| | - Alfonso Lampen
- Department of Food Safety, Federal Institute for Risk Assessment, Max-Dohrn-Straße 8-10, 10589 Berlin, Germany
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Xia Q, Ma L, He X, Cai L, Fu PP. 7-glutathione pyrrole adduct: a potential DNA reactive metabolite of pyrrolizidine alkaloids. Chem Res Toxicol 2015; 28:615-20. [PMID: 25768656 DOI: 10.1021/tx500417q] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyrrolizidine alkaloid (PA)-containing plants are the most common poisonous plants affecting livestock, wildlife, and humans. PAs require metabolic activation to form pyrrolic metabolites to exert cytotoxicity and tumorigenicity. We previously determined that metabolism of tumorigenic PAs produced four DNA adducts, designated as DHP-dG-3, DHP-dG-4, DHP-dA-3, and DHP-dA-4, that are responsible for liver tumor initiation. 7-Glutathione-(±)-6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine (7-GS-DHP), formed in vivo and in vitro, and 7,9-di-GS-DHP, formed in vitro, are both considered detoxified metabolites. However, in this study we determined that incubation of 7-GS-DHP with 2'-deoxyguanosine (dG) and 2'-deoxyadenosine (dA) yields DHP-dG-3, DHP-dG-4, DHP-dA-3, and DHP-dA-4 adducts as well as the reactive metabolite DHP. Furthermore, reaction of 7-GS-DHP with calf thymus DNA in aqueous solution at 37 °C for 4, 8, 16, 24, 48, or 72 h, followed by enzymatic hydrolysis yielded DHP-dG-3, DHP-dG-4, DHP-dA-3, and DHP-dA-4 adducts. Under our current experimental conditions, DHP-dA-3 and DHP-dA-4 adducts were formed in a trace amount from the reaction of 7,9-di-GS-DHP with dA. No DHP-dG-3 or DHP-dG-4 adducts were detected from the reaction of 7,9-di-GS-DHP with dG. This study represents the first report that the 7-GS-DHP adduct can be a potential reactive metabolite of PAs leading to DNA adduct formation.
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Affiliation(s)
- Qingsu Xia
- †National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Liang Ma
- †National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Xiaobo He
- †National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Lining Cai
- ‡Biotranex LLC, Monmouth Junction, New Jersey 08852, United States
| | - Peter P Fu
- †National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
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Amara AAAF. An overview of the molecular and cellular interactions of some bioactive compounds. BIOTECHNOLOGY OF BIOACTIVE COMPOUNDS 2015:525-554. [DOI: 10.1002/9781118733103.ch21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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11
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Japanese Butterbur (Petasites japonicus) Leaves Increase Hepatic Oxidative Stress in Male Rats. Biosci Biotechnol Biochem 2014; 76:2026-31. [DOI: 10.1271/bbb.120294] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Tu M, Sun S, Wang K, Peng X, Wang R, Li L, Zeng S, Zhou H, Jiang H. Organic cation transporter 1 mediates the uptake of monocrotaline and plays an important role in its hepatotoxicity. Toxicology 2013; 311:225-30. [PMID: 23831208 DOI: 10.1016/j.tox.2013.06.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/02/2013] [Accepted: 06/26/2013] [Indexed: 12/14/2022]
Abstract
Monocrotaline (MCT) is a kind of toxic retronecine-type pyrrolizidine alkaloids (PAs) from plants of Crotalaria, which can be bio-activated by cytochrome P450 (CYP) enzymes in liver and then induce hepatotoxicity. Since CYPs are localized in the endoplasmic reticulum, the influx of MCT to the liver is the key step for its hepatotoxicity. The objective of the present study was to investigate the role of organic cation transporter 1 (OCT1), a transporter mainly expressed in liver, in the uptake of MCT and in hepatotoxicity induced by MCT. The results revealed that MCT markedly inhibited the uptake of 1-methyl-4-phenylpyridinium (MPP(+)), an OCT1 substrate, in Madin-Darby canine kidney (MDCK) cells stably expressing human OCT1 (MDCK-hOCT1) with the IC50 of 5.52±0.56μM. The uptake of MCT was significantly higher in MDCK-hOCT1 cells than in MDCK-mock cells, and MCT uptake in MDCK-hOCT1 cells followed Michaelis-Menten kinetics with the Km and Vmax values of 25.0±6.7μM and 266±64pmol/mg protein/min, respectively. Moreover, the OCT1 inhibitors, such as quinidine, d-tetrahydropalmatine (d-THP), obviously inhibited the uptake of MCT in MDCK-hOCT1 cells and isolated rat primary hepatocytes, and attenuated the viability reduction and LDH release of the primary cultured rat hepatocytes caused by MCT. In conclusion, OCT1 mediates the hepatic uptake of MCT and may play an important role in MCT induced-hepatotoxicity.
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Affiliation(s)
- Meijuan Tu
- Department of Pharmaceutical Analysis and Drug Metabolism, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, PR China
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Barbehenn RV, Kochmanski J. Searching for synergism: effects of combinations of phenolic compounds and other toxins on oxidative stress in Lymantria dispar caterpillars. CHEMOECOLOGY 2013. [DOI: 10.1007/s00049-013-0136-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Pitanga BPS, Nascimento RP, Silva VDA, Costa SL. The Role of Astrocytes in Metabolism and Neurotoxicity of the Pyrrolizidine Alkaloid Monocrotaline, the Main Toxin of Crotalaria retusa. Front Pharmacol 2012; 3:144. [PMID: 22876233 PMCID: PMC3411086 DOI: 10.3389/fphar.2012.00144] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 07/05/2012] [Indexed: 01/19/2023] Open
Abstract
The metabolic interactions and signaling between neurons and glial cells are necessary for the development and maintenance of brain functions and structures and for neuroprotection, which includes protection from chemical attack. Astrocytes are essential for cerebral detoxification and present an efficient and specific cytochrome P450 enzymatic system. Whilst Crotalaria (Fabaceae, Leguminosae) plants are used in popular medicine, they are considered toxic and can cause damage to livestock and human health problems. Studies in animals have shown cases of poisoning by plants from the genus Crotalaria, which induced damage to the central nervous system. This finding has been attributed to the toxic effects of the pyrrolizidine alkaloid (PA) monocrotaline (MCT). The involvement of P450 enzymatic systems in MCT hepatic and pulmonary metabolism and toxicity has been elucidated, but little is known about the pathways implicated in the bioactivation of these systems and the direct contribution of these systems to brain toxicity. This review will present the main toxicological aspects of the Crotalaria genus that are established in the literature and recent findings describing the mechanisms involved in the neurotoxic effects of MCT, which was extracted from Crotalaria retusa, and its interaction with neurons in isolated astrocytes.
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Affiliation(s)
- Bruno Penas Seara Pitanga
- Laboratório de Neuroquímica e Biologia Celular, Instituto de Ciências da Saúde, Universidade Federal da Bahia Salvador, Brazil
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Pitanga BPS, Silva VDA, Souza CS, Junqueira HA, Fragomeni BON, Nascimento RP, Silva AR, Costa MDFD, El-Bachá RS, Costa SL. Assessment of neurotoxicity of monocrotaline, an alkaloid extracted from Crotalaria retusa in astrocyte/neuron co-culture system. Neurotoxicology 2011; 32:776-84. [PMID: 21781985 DOI: 10.1016/j.neuro.2011.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 06/09/2011] [Accepted: 07/04/2011] [Indexed: 10/18/2022]
Abstract
Studies have shown cases of poisoning with plants from the genus Crotalaria (Leguminosae) mainly in animals. They induce damages in the central nervous system (CNS), which has been attributed to toxic effects of the pyrrolizidine alkaloid (PA) monocrotaline (MCT). Previously we demonstrated that both MCT and dehydromonocrotaline (DHMC), its main active metabolite, induce changes in the levels and patterns of expression of the main protein from astrocyte cytoskeleton, glial fibrillary acidic protein (GFAP). In this study we investigated the effect of MCT on rat cortical astrocyte/neuron primary co-cultures. Primary cultures were exposed to 10 or 100 μM MCT. The MTT test and the measurement of LDH activity on the culture medium revealed that after 24h exposure MCT was not cytotoxic to neuron/astrocyte cells. However, the cell viability after 72 h treatment decreased in 10-20%, and the LDH levels in the culture medium increased at a rate of 12% and 23%, in cultures exposed to 10 or 100 μM MCT. Rosenfeld staining showed vacuolization and increase in cell body in astrocytes after MCT exposure. Immunocytochemistry and Western blot analyses revealed changes on pattern of GFAP and βIII-tubulin expression and steady state levels after MCT treatment, with a dose and time dependent intense down regulation and depolarization of neuronal βIII-tubulin. Moreover, treatment with 100 μM MCT for 12h induced GSH depletion, which was not seen when cytochrome P450 enzyme system was inhibited indicating that it is involved in MCT induced cytotoxicity in CNS cells.
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Affiliation(s)
- Bruno P S Pitanga
- Laboratório de Neuroquímica e Biologia Celular, Departamento de Biofunção/Bioquímica, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Av. Reitor Miguel Calmon s/n, Salvador, BA, 40.110-902, Brazil
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Maioli MA, Alves LC, Perandin D, Garcia AF, Pereira FTV, Mingatto FE. Cytotoxicity of monocrotaline in isolated rat hepatocytes: effects of dithiothreitol and fructose. Toxicon 2011; 57:1057-64. [PMID: 21530570 DOI: 10.1016/j.toxicon.2011.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 04/07/2011] [Accepted: 04/12/2011] [Indexed: 12/18/2022]
Abstract
Monocrotaline (MCT) is a pyrrolizidine alkaloid present in plants of the Crotalaria species that causes cytotoxicity and genotoxicity, including hepatotoxicity in animals and humans. It is metabolized by cytochrome P-450 in the liver to the alkylating agent dehydromonocrotaline (DHM). In previous studies using isolated rat liver mitochondria, we observed that DHM, but not MCT, inhibited the activity of respiratory chain complex I and stimulated the mitochondrial permeability transition with the consequent release of cytochrome c. In this study, we evaluated the effects of MCT and DHM on isolated rat hepatocytes. DHM, but not MCT, caused inhibition of the NADH-linked mitochondrial respiration. When hepatocytes of rats pre-treated with dexamethasone were incubated with MCT (5 mM), they showed ALT leakage, impaired ATP production and decreased levels of intracellular reduced glutathione and protein thiols. In addition, MCT caused cellular death by apoptosis. The addition of fructose or dithiotreitol to the isolated rat hepatocyte suspension containing MCT prevented the ATP depletion and/or glutathione or thiol oxidation and decreased the ALT leakage and apoptosis. These results suggest that the toxic effect of MCT on hepatocytes may be caused by metabolite-induced mitochondrial energetic impairment, together with a decrease of cellular glutathione and protein thiols.
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Affiliation(s)
- Marcos A Maioli
- Laboratório de Bioquímica Metabólica e Toxicológica, UNESP-Univ Estadual Paulista, Campus de Dracena, 17900-000 Dracena, SP, Brazil
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17
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Amin KA, Hassan MS, Awad EST, Hashem KS. The protective effects of cerium oxide nanoparticles against hepatic oxidative damage induced by monocrotaline. Int J Nanomedicine 2011; 6:143-9. [PMID: 21289991 PMCID: PMC3026579 DOI: 10.2147/ijn.s15308] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Objective The objective of the present study was to determine the ability of cerium oxide (CeO2) nanoparticles to protect against monocrotaline (MCT)-induced hepatotoxicity in a rat model. Method Twenty male Sprague Dawley rats were arbitrarily assigned to four groups: control (received saline), CeO2 (given 0.0001 nmol/kg intraperitoneally [IP]), MCT (given 10 mg/kg body weight IP as a single dose), and MCT + CeO2 (received CeO2 both before and after MCT). Electron microscopic imaging of the rat livers was carried out, and hepatic total glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPX), glutathione S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) enzymatic activities were quantified. Results Results showed a significant MCT-induced decrease in total hepatic GSH, GPX, GR, and GST normalized to control values with concurrent CeO2 administration. In addition, MCT produced significant increases in hepatic CAT and SOD activities, which also ameliorated with CeO2. Conclusions These results indicate that CeO2 acts as a putative novel and effective hepatoprotective agent against MCT-induced hepatotoxicity.
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Affiliation(s)
- Kamal A Amin
- Department of Biochemistry, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt.
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18
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Silva-Neto J, Barreto R, Pitanga B, Souza C, Silva V, Silva A, Velozo E, Cunha S, Batatinha M, Tardy M, Ribeiro C, Costa M, El-Bachá R, Costa S. Genotoxicity and morphological changes induced by the alkaloid monocrotaline, extracted from Crotalaria retusa, in a model of glial cells. Toxicon 2010; 55:105-17. [DOI: 10.1016/j.toxicon.2009.07.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 07/08/2009] [Accepted: 07/09/2009] [Indexed: 11/27/2022]
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Xiong A, Yang L, He Y, Zhang F, Wang J, Han H, Wang C, Bligh SWA, Wang Z. Identification of metabolites of adonifoline, a hepatotoxic pyrrolizidine alkaloid, by liquid chromatography/tandem and high-resolution mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:3907-3916. [PMID: 19918941 DOI: 10.1002/rcm.4329] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Hepatotoxic pyrrolizidine alkaloid (HPA)-containing plants have always been a threat to human and livestock health worldwide. Adonifoline, a main HPA in Senecio scandens Buch.-Ham. ex D. Don (Qianli guang), was used officially as an infusion in cases of oral and pharyngeal infections in China. In this study in vivo metabolism of adonifoline was studied for the first time by identifying the metabolites of adonifoline present in bile, urine and feces of rats using liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS(n)) (ion trap) as well as liquid chromatography/electrospray ionization high-resolution mass spectrometry (LC/ESI-HRMS) (quadrupole-time of flight). In total 19 metabolites were identified and, among them, retronecine-N-oxides were confirmed by matching their fragmentation patterns with their fully characterized synthetic compounds. These metabolites are all involved in both phase I and phase II metabolic processes and the principal in vivo metabolism pathways of adonifoline were proposed.
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Affiliation(s)
- 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 201210, China
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20
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Chen Y, Ji L, Wang H, Wang Z. Intracellular glutathione plays important roles in pyrrolizidine alkaloids-induced growth inhibition on hepatocytes. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2009; 28:357-362. [PMID: 21784027 DOI: 10.1016/j.etap.2009.06.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 05/31/2009] [Accepted: 06/13/2009] [Indexed: 05/31/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are well-known natural hepatotoxins distributed widely in thousands of plants in the world. Adonifoline (Adon), senecionine (Sene) and monocrotaline (Mono) are retronecine-type PAs, and the present study is designed to observe the effects of intracellular glutathione on toxicity of these three PAs in human normal liver L-02 cells. The ratio of cellular reduced glutathione (GSH) and oxidized glutathione (GSSG) was assayed after L-02 cells were incubated with these three PAs for various times. Results showed that Adon, Sene and Mono all significantly decreased the ratio of GSH/GSSG in L-02 cells in the time- and concentration-dependent manner. The results of 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) and trypan blue staining assay showed that these three PAs all significantly decreased cell viability in L-02 cells when pretreated with 10μM BSO (L-Buthionine-S-R-Sulfoximine) for 24h to deplete intracellular GSH. Further results showed that anti-oxidant compounds such as NAC (N-Acetyl-Cysteine) and GSH could rescue the cytotoxicity caused by these three PAs with BSO pretreatment. Taken together, those results suggest that intracellular GSH plays important roles in regulating the cytotoxicity induced by PAs.
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Affiliation(s)
- Ying Chen
- Department of Pharmacognosy, China Pharmaceutical University, Nanjing, 210038, PR China; Key Laboratory of Standardization of Chinese Medicines of Ministry of Education, Shanghai Key Laboratory of Complex Prescription, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China
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dos Santos AB, Dorta DJ, Pestana CR, Maioli MA, Curti C, Mingatto FE. Dehydromonocrotaline induces cyclosporine A-insensitive mitochondrial permeability transition/cytochrome c release. Toxicon 2009; 54:16-22. [PMID: 19285518 DOI: 10.1016/j.toxicon.2009.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 02/17/2009] [Accepted: 03/02/2009] [Indexed: 12/29/2022]
Abstract
Monocrotaline (MCT) is a pyrrolizidine alkaloid present in plants of the genus Crotalaria that causes cytotoxicity and genotoxicity in animals and humans. It is well established that the toxicity of MCT results from its hepatic bioactivation to dehydromonocrotaline (DHM), an alkylating agent, but the exact mechanism of action remains unknown. In a previous study, we demonstrated DHM's inhibition of mitochondrial NADH-dehydrogenase activity at micromolar concentrations, which is an effect associated with a significant reduction in ATP synthesis. As a follow-up study, we have evaluated the ability of DHM to induce mitochondrial permeability transition (MPT) and its associated processes in isolated rat liver mitochondria. In the presence of 10 microM Ca(2+), DHM (50-250 microM) elicited MPT in a concentration-dependent, but cyclosporine A-independent manner, as assessed by mitochondrial swelling, which is associated with mitochondrial Ca(2+) efflux and cytochrome c release. DHM (50-250 microM) did not cause hydrogen peroxide accumulation but did deplete endogenous glutathione and NAD(P)H, while oxidizing protein thiol groups. These results potentially indicate the involvement of mitochondria, via apoptosis, in the well-documented cytotoxicity of monocrotaline.
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Affiliation(s)
- Aline Buda dos Santos
- Laboratório de Bioquímica, Faculdade de Zootecnia, Universidade Estadual Paulista Júlio de Mesquita Filho, Campus de Dracena, 17900-000 Dracena, SP, Brazil
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Monocrotaline pyrrol is cytotoxic and alters the patterns of GFAP expression on astrocyte primary cultures. Toxicol In Vitro 2008; 22:1191-7. [DOI: 10.1016/j.tiv.2008.03.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Revised: 02/21/2008] [Accepted: 03/23/2008] [Indexed: 11/18/2022]
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Hess JB, Mosjidis JA. Effect of Sunn Hemp Seed Inclusion in Broiler Starter Diets on Live Performance Attributes. JOURNAL OF APPLIED ANIMAL RESEARCH 2008. [DOI: 10.1080/09712119.2008.9706908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Mingatto FE, Dorta DJ, dos Santos AB, Carvalho I, da Silva CHTP, da Silva VB, Uyemura SA, dos Santos AC, Curti C. Dehydromonocrotaline inhibits mitochondrial complex I. A potential mechanism accounting for hepatotoxicity of monocrotaline. Toxicon 2007; 50:724-30. [PMID: 17669457 DOI: 10.1016/j.toxicon.2007.06.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 06/05/2007] [Accepted: 06/06/2007] [Indexed: 11/21/2022]
Abstract
Monocrotaline is a pyrrolizidine alkaloid present in plants of the Crotalaria species, which causes cytotoxicity and genotoxicity, including hepatotoxicity in animals and humans. It is metabolized by cytochrome P-450 in the liver to the alkylating agent dehydromonocrotaline. We evaluated the effects of monocrotaline and its metabolite on respiration, membrane potential and ATP levels in isolated rat liver mitochondria, and on respiratory chain complex I NADH oxidase activity in submitochondrial particles. Dehydromonocrotaline, but not the parent compound, showed a concentration-dependent inhibition of glutamate/malate-supported state 3 respiration (respiratory chain complex I), but did not affect succinate-supported respiration (complex II). Only dehydromonocrotaline dissipated mitochondrial membrane potential, depleted ATP, and inhibited complex I NADH oxidase activity (IC50=62.06 microM) through a non-competitive type of inhibition (K(I)=8.1 microM). Therefore, dehydromonocrotaline is an inhibitor of the activity of respiratory chain complex I NADH oxidase, an action potentially accounting for the well-documented monocrotaline's hepatotoxicity to animals and humans. The mechanism probably involves change of the complex I conformation resulting from modification of cysteine thiol groups by the metabolite.
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Affiliation(s)
- Fábio E Mingatto
- Laboratório de Bioquímica, Faculdade de Zootecnia, Universidade Estadual Paulista Júlio de Mesquita Filho, Campus de Dracena, 17900-000 Dracena, SP, Brazil.
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Fu PP, Xia Q, Lin G, Chou MW. Pyrrolizidine Alkaloids—Genotoxicity, Metabolism Enzymes, Metabolic Activation, and Mechanisms. Drug Metab Rev 2004; 36:1-55. [PMID: 15072438 DOI: 10.1081/dmr-120028426] [Citation(s) in RCA: 368] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Pyrrolizidine alkaloid-containing plants are widely distributed in the world and are probably the most common poisonous plants affecting livestock, wildlife, and humans. Because of their abundance and potent toxicities, the mechanisms by which pyrrolizidine alkaloids induce genotoxicities, particularly carcinogenicity, were extensively studied for several decades but not exclusively elucidated until recently. To date, the pyrrolizidine alkaloid-induced genotoxicities were revealed to be elicited by the hepatic metabolism of these naturally occurring toxins. In this review, we present updated information on the metabolism, metabolizing enzymes, and the mechanisms by which pyrrolizidine alkaloids exert genotoxicity and tumorigenicity.
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Affiliation(s)
- Peter P Fu
- National Center for Toxicological Research, Jefferson, Arkansas 72079, USA.
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26
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Genotoxic Pyrrolizidine Alkaloids — Mechanisms Leading to DNA Adduct Formation and Tumorigenicity. Int J Mol Sci 2002. [DOI: 10.3390/i3090948] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Lin G, Nnane IP, Cheng TY. The effects of pretreatment with glycyrrhizin and glycyrrhetinic acid on the retrorsine-induced hepatotoxicity in rats. Toxicon 1999; 37:1259-70. [PMID: 10400287 DOI: 10.1016/s0041-0101(98)00263-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A wide variety of medicinal herbs contain hepatotoxic pyrrolizidine alkaloids (PAs), and often cause acute and chronic liver damages in man. Liquorice, a known antihepatitis, is commonly used with PA-containing herbs concurrently, and hepatotoxicity induced by such combined uses was not pronounced. The present study is to investigate effects of glycyrrhizin (GL) and 18beta-glycyrrhetinic acid (GA), the major biologically active ingredients of liquorice, against PA-induced hepatotoxicity in rats. Single dose (35 mg/kg, i.p.) of retrorsine (RET), a typical potent hepatotoxic PA, was given to rats to induce liver injury. A single dose pretreatment with GL or GA prior to retrorsine challenge did not show hepatoprotection. However, when rats were pretreated with either GL (200 mg/kg/day, i.p.) or GA (10 mg/kg/day, i.p.) for three consecutive days prior to retrorsine exposure, the elevated serum GOT and GPT levels induced by retrorsine were significantly reduced. Serum levels of transaminases almost returned to normal (GOT: 56+/-2 (control), 104+/-5 (RET), 64+/-3 (GL + RET) and 59+/-3 (GA + RET). GPT: 40+/-2 (control), 90+/-7 (RET), 45+/-2 (GL + RET) and 45+/-4 (GA + RET) SF units/ml). Furthermore, no extensive hepatocellular damages were observed. The results demonstrated that a three-day pretreatment with either GL or GA exhibited protective effect on retrorsine-induced liver damage in rats.
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Affiliation(s)
- G Lin
- Department of Pharmacology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, NT.
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Sun Y, Hasal SJ, Yan CC, Brendel K, Huxtable RJ. Pyrrolizidine alkaloid-induced depletion of taurine from rat liver in vivo and in vitro. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 442:71-7. [PMID: 9635016 DOI: 10.1007/978-1-4899-0117-0_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Y Sun
- Department of Pharmacology, University of Arizona, College of Medicine, Tucson 85724, USA
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Yan CC, Huxtable RJ. Effects of monocrotaline, a pyrrolizidine alkaloid, on glutathione metabolism in the rat. Biochem Pharmacol 1996; 51:375-9. [PMID: 8573205 DOI: 10.1016/0006-2952(95)02189-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Monocrotaline (MONO), a pyrrolizidine alkaloid, causes veno-occlusive disease of the liver, pulmonary arterial hypertension, and right ventricular hypertrophy. Toxicity is due to the hepatic formation of a pyrolic metabolite that can be detoxified by conjugation with glutathione (GSH). We have shown that the GSH content of the liver affects the quantity of the pyrrolic metabolite that is released from the liver. We have now examined whether MONO, in turn, affects GSH metabolism. Twenty-four hours after administration of MONO to rats (65 mg/kg, i.p.), the highest concentration of bound pyrrolic metabolites was found in the liver, followed by the lung and kidney. Heart and brain contained lower concentrations of these metabolites. Significantly higher levels of GSH were found in liver and lungs of MONO-treated rats than in saline-injected control animals. In the liver, activities of the following enzymes were elevated: gamma-glutamylcysteine synthetase, GSH synthetase, gamma-glutamyl transpeptidase, dipeptidase, and microsomal GSH transferase. The same changes were seen in the lung. In the heart, gamma-glutamyl transpeptidase activity was decreased markedly, and cytosolic GSH transferase activity was elevated. In the kidney, the activities of GSH synthetase, gamma-glutamyl transpeptidase, and cytosolic GSH transferase were increased. Our results establish a mutual interaction of MONO and sulfur metabolism. It appears that an early metabolic action of MONO is to modify sulfur amino acid metabolism, diverting cysteine metabolism from oxidation to taurine towards synthesis of GSH.
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Affiliation(s)
- C C Yan
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson 85724, USA
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Yan CC, Huxtable RJ. Effects of taurine and guanidinoethane sulfonate on toxicity of the pyrrolizidine alkaloid monocrotaline. Biochem Pharmacol 1996; 51:321-9. [PMID: 8573199 DOI: 10.1016/0006-2952(95)02185-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Monocrotaline (MONO), a pyrrolizidine alkaloid, causes pulmonary arterial hypertension and right ventricular hypertrophy due to hepatic metabolism to the alkylating pyrrole dehydromonocrotaline. Taurine a sulfonic amino acid, is hepato- and cardioprotective in a variety of conditions. We have examined the effects of taurine and its amidino analog, guanidinoethane sulfonate (GES), in rats injected i.p. with MONO (65 mg/kg). Taurine and GES were given as 1% solutions in drinking water beginning 14 days before administration of MONO and continuing for 14 days therafter, when the rats were killed. The MONO group had right ventricular hypertrophy and pulmonary hyperplasia. Compared with control, no significant changes in the right ventricle/left ventricle weight ratio, or the right ventricle/body weight ratio occurred in rats also given taurine of GES. Lung weights in these two groups were higher than in the control group, but below that of the MONO-alone group. The lethality of MONO over 14 days was decreased by taurine (LD50 for MONO alone 80 mg/kg; for MONO + taurine 121 mg/kg). Rats given only MONO had lower hepatic concentrations of GSH and cysteine (Cys), and higher activities of microsomal GSH transferase activity were no different from control. Gamma-Glutamylcysteine (Glu-Cys) synthetase and gamma-glutamyl transpeptidase activities were elevated. In MONO-injected rats given GES, hepatic GSH levels were higher and Cys levels were lower than in either the MONO alone or MONO + taurine groups. Gamma-Glu-Cys synthetase activity was depressed. Microsomal GSH transferase, GSH peroxidase and gamma-glutamyl transpeptidase activities were elevated. Livers of MONO-injected animals showed higher levels of serine (reversed by both taurine and GES) and glycine (Gly; reversed by GES) and lower levels of glutamine. Compared with control rats, the following changes occurred in serum amino acids: MONO alone: increased aspartate, taurine and lysine; taurine-supplemented: increased taurine, methionine (Met) and lysine, and decreased Gly; GES-supplemented: decreased asparagine, serine, Gly, arginine, taurine, and valine. Compared with the MONO-alone group, the taurine-supplemented group had higher glutamate (Glu), Met and alanine, and the GES-supplemented group higher alanine and lower serine, Gly, arginine and valine. We conclude that taurine protects against MONO-induced lethality and right ventricular hypertrophy. GES also protects against right ventricular hypertrophy. However, these agents act by different mechanisms, taurine preventing many of the biochemical changes induced by MONO, with GES inducing additional changes.
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Affiliation(s)
- C C Yan
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson 85724, USA
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Yan CC, Huxtable RJ. Effect of the pyrrolizidine alkaloid monocrotaline on taurine and sulfur amino acid metabolism in the rat liver. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 403:135-45. [PMID: 8915351 DOI: 10.1007/978-1-4899-0182-8_16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- C C Yan
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson 85724, USA
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Yan CC, Huxtable RJ. Effect of taurine on toxicity of the pyrrolizidine alkaloid monocrotaline in rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1996; 403:315-25. [PMID: 8915367 DOI: 10.1007/978-1-4899-0182-8_33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- C C Yan
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson 85724, USA
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