1
|
He X, Xia Q, Zhu L, He Y, Bryant MS, Lin G, Fu PP. Formation of DHP-DNA Adducts from Rat Liver Microsomal Metabolism of 1,2-Unsaturated Pyrrolizidine Alkaloid-Containing Plant Extracts and Dietary Supplements. Chem Res Toxicol 2023; 36:243-250. [PMID: 36705520 DOI: 10.1021/acs.chemrestox.2c00321] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
1,2-Unsaturated pyrrolizidine alkaloids (PAs) are carcinogenic phytochemicals. We previously determined that carcinogenic PAs and PA N-oxides commonly form a set of four (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-DNA adducts, namely, DHP-dG-3, DHP-dG-4, DHP-dA-3, and DHP-dA-4. This set of DHP-DNA adducts has been implicated as a potential biomarker of PA-induced liver tumor initiation from metabolism of individual carcinogenic PAs. To date, it is not known whether this generality occurs from metabolism of PA-containing plant extracts. In this study, we investigate the rat liver microsomal metabolism of nine PA-containing plant extracts and two PA-containing dietary supplements in the presence of calf thymus DNA. The presence of carcinogenic PAs and PA N-oxides in plant extracts was first confirmed by LC-MS/MS analysis with selected reaction monitoring mode. Upon rat liver microsomal metabolism of these PA-containing plant extracts and dietary supplements, the formation of this set of DHP-DNA adducts was confirmed. Thus, these results indicate that metabolism of PA-containing plant extracts and dietary supplements can generate DHP-dG-3, DHP-dG-4, DHP-dA-3, and DHP-dA-4 adducts, thereby potentially initiating liver tumor formation.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Qingsu Xia
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Lin Zhu
- School of Biomedical Science, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, The People's Republic of China
| | - Yisheng He
- School of Biomedical Science, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, The People's Republic of China
| | - Matthew S Bryant
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Ge Lin
- School of Biomedical Science, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, The People's Republic of China
| | - Peter P Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| |
Collapse
|
2
|
Xiao Y, Yi H, Wang G, Chen S, Li X, Wu Q, Zhang S, Deng K, He Y, Yang X. Electrochemiluminescence sensor for point-of-care detection of pyrrolizidine alkaloids. Talanta 2022; 249:123645. [PMID: 35700647 DOI: 10.1016/j.talanta.2022.123645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 05/28/2022] [Accepted: 05/31/2022] [Indexed: 10/31/2022]
Abstract
Pyrrolizidine alkaloids (PAs) and PA N-oxides are hepatotoxic natural products, produced by over 6000 plant species worldwide. However, an unmet need remains for confirmative measurement of PAs in routine clinical tests. Here, we develop a visual, easy-to-use, and economic mesoporous silica-electrochemiluminescence (MPS-ECL) sensor for point-of-care (POC) testing of PAs, utilizing MPS's amplification effect on positive ions. The relationship between PAs' different structures and corresponding Ru(bpy)32+ ECL activity shows that reaction mechanism, stability of intermediate, molecular geometry and alternative anodic reactivity significantly affect the ECL activity. The ECL intensity varies among different PAs: monocrotaline ˃ senecionine N-oxide ˃ retrorsine ˃ senkirkine. The POC sensors possess excellent linearity (0.9993 > R2 > 0.9944), low detection limits (0.02 μM-0.07 μM), and good recoveries (90.12%-105.93%), indicating good accuracy and practicability. The portable and low-cost sensor is user-friendly, which holds promise to be applied to POC testing of PAs in drugs, food products, and clinical samples, which is promising for initial assessments of PA-induced health risk.
Collapse
Affiliation(s)
- Yi Xiao
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China; John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - Haomin Yi
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Guofang Wang
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Suhua Chen
- Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China
| | - Xiang Li
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Qinyu Wu
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Siyi Zhang
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Kexin Deng
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Yisheng He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
| | - Xiaoping Yang
- Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China.
| |
Collapse
|
3
|
Ma J, Li M, Li N, Chan WY, Lin G. Pyrrolizidine Alkaloid-Induced Hepatotoxicity Associated with the Formation of Reactive Metabolite-Derived Pyrrole-Protein Adducts. Toxins (Basel) 2021; 13:723. [PMID: 34679016 PMCID: PMC8540779 DOI: 10.3390/toxins13100723] [Citation(s) in RCA: 6] [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: 09/28/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 12/19/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) with 1,2-unsaturated necine base are hepatotoxic phytotoxins. Acute PA intoxication is initiated by the formation of adducts between PA-derived reactive pyrrolic metabolites with cellular proteins. The present study aimed to investigate the correlation between the formation of hepatic pyrrole-protein adducts and occurrence of PA-induced liver injury (PA-ILI), and to further explore the use of such adducts for rapidly screening the hepatotoxic potency of natural products which contain PAs. Aqueous extracts of Crotalaria sessiliflora (containing one PA: monocrotaline) and Gynura japonica (containing two PAs: senecionine and seneciphylline) were orally administered to rats at different doses for 24 h to investigate PA-ILI. Serum alanine aminotransferase (ALT) activity, hepatic glutathione (GSH) level, and liver histological changes of the treated rats were evaluated to assess the severity of PA-ILI. The levels of pyrrole-protein adducts formed in the rats' livers were determined by a well-established spectrophotometric method. The biological and histological results showed a dose-dependent hepatotoxicity with significantly different toxic severity among groups of rats treated with herbal extracts containing different PAs. Both serum ALT activity and the amount of hepatic pyrrole-protein adducts increased in a dose-dependent manner. Moreover, the elevation of ALT activity correlated well with the formation of hepatic pyrrole-protein adducts, regardless of the structures of different PAs. The findings revealed that the formation of hepatic pyrrole-protein adducts-which directly correlated with the elevation of serum ALT activity-was a common insult leading to PA-ILI, suggesting a potential for using pyrrole-protein adducts to screen hepatotoxicity and rank PA-containing natural products, which generally contain multiple PAs with different structures.
Collapse
Affiliation(s)
- Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 4054577, China; (J.M.); (M.L.); (N.L.); (W.Y.C.)
- School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou 510000, China
| | - Mi Li
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 4054577, China; (J.M.); (M.L.); (N.L.); (W.Y.C.)
| | - Na Li
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 4054577, China; (J.M.); (M.L.); (N.L.); (W.Y.C.)
| | - Wood Yee Chan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 4054577, China; (J.M.); (M.L.); (N.L.); (W.Y.C.)
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 4054577, China; (J.M.); (M.L.); (N.L.); (W.Y.C.)
| |
Collapse
|
4
|
He X, Xia Q, Shi Q, Fu PP. Metabolism of carcinogenic pyrrolizidine alkaloids and pyrrolizidine alkaloid N-oxides by rat primary hepatocytes generate the same characteristic DHP-DNA adducts. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, TOXICOLOGY AND CARCINOGENESIS 2021; 39:357-372. [PMID: 35895950 DOI: 10.1080/26896583.2021.1954460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We recently established a genotoxic mechanism mediated by a set of (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-DNA adducts, which lead to pyrrolizidine alkaloid (PA)-induced liver tumor initiation. This mechanism is involved in the metabolism of a series of carcinogenic PAs and PA N-oxides in rats in vivo and in vitro. There is a correlation between the order of liver tumor potency and the level of DHP-DNA adduct formation. Thus, these DHP-DNA adducts can be potential biomarkers of PA and PA N-oxide exposure and liver tumor initiation. To establish the generality of this mechanism, in the present study, we examined the metabolism of 13 potential carcinogenic PAs, 1 non-carcinogenic PA, and 5 PA N-oxides by male rat primary hepatocytes. With the exception of the nontoxic PA and vehicle control, all treated groups produced identical set of DHP-DNA adducts. These results support a general genotoxic mechanism mediated by the formation of characteristic DHP-DNA adducts leading to PA-induced liver tumor initiation.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research, Jefferson, AR, USA
| | - Qingsu Xia
- National Center for Toxicological Research, Jefferson, AR, USA
| | - Qiang Shi
- National Center for Toxicological Research, Jefferson, AR, USA
| | - Peter P Fu
- National Center for Toxicological Research, Jefferson, AR, USA
| |
Collapse
|
5
|
He Y, Zhu L, Ma J, Lin G. Metabolism-mediated cytotoxicity and genotoxicity of pyrrolizidine alkaloids. Arch Toxicol 2021; 95:1917-1942. [PMID: 34003343 DOI: 10.1007/s00204-021-03060-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/21/2021] [Indexed: 02/06/2023]
Abstract
Pyrrolizidine alkaloids (PAs) and PA N-oxides are common phytotoxins produced by over 6000 plant species. Humans are frequently exposed to PAs via ingestion of PA-containing herbal products or PA-contaminated foods. PAs require metabolic activation to form pyrrole-protein adducts and pyrrole-DNA adducts which lead to cytotoxicity and genotoxicity. Individual PAs differ in their metabolic activation patterns, which may cause significant difference in toxic potency of different PAs. This review discusses the current knowledge and recent advances of metabolic pathways of different PAs, especially the metabolic activation and metabolism-mediated cytotoxicity and genotoxicity, and the risk evaluation methods of PA exposure. In addition, this review provides perspectives of precision toxicity assessment strategies and biomarker development for the risk control and translational investigations of human intoxication by PAs.
Collapse
Affiliation(s)
- Yisheng He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Lin Zhu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China.
| |
Collapse
|
6
|
He X, Xia Q, Zhao Y, Fu PP. 1-Formyl-7-hydroxy-6,7-dihydro-5 H-pyrrolizine (1-CHO-DHP)-Cysteine Conjugates: Metabolic Formation and Binding to Cellular DNA. Chem Res Toxicol 2020; 33:2139-2146. [PMID: 32588618 DOI: 10.1021/acs.chemrestox.0c00143] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
1-Formyl-7-hydroxy-6,7-dihydro-5H-pyrrolizine (1-CHO-DHP) is a potential proximate carcinogenic metabolite of pyrrolizidine alkaloids. In the present study, we determined that the reaction of 1-CHO-DHP with cysteine generated four identified products. By mass and 1H NMR spectral analyses, these products are cysteinyl-[2'-S-7]-1-CHO-DHP (P2), cysteinyl-[3'-N-7]-1-CHO-DHP (P3), 7-keto-DHP (P4), and 1-cysteinylimino-DHP (P5). These four compounds were also formed from the incubation of 1-CHO-DHP in HepG2 cells. Compounds P3 and P5 were interconvertible in acetonitrile and water. Incubation of P2 in HepG2 cells generated the four DHP-dG and -dA adducts that we propose to be potential common biomarkers of pyrrolizidine alkaloids exposure and pyrrolizidine alkaloids-induced liver tumor initiation. These four DHP-DNA adducts were also formed from the incubation of a mixture of P3 and P5 in HepG2 cells but not from the incubation with 7-keto-DHP. From the reaction of 1-CHO-DHP with glutathione, only trace amounts of the glutathione-1-CHO-DHP adduct were detected, with the structure unable to be characterized.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Qingsu Xia
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Yuewei Zhao
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| | - Peter P Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, United States
| |
Collapse
|
7
|
He X, Xia Q, Shi Q, Fu PP. Effects of glutathione and cysteine on pyrrolizidine alkaloid-induced hepatotoxicity and DNA adduct formation in rat primary hepatocytes. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, TOXICOLOGY AND CARCINOGENESIS 2020; 38:109-123. [PMID: 32500832 DOI: 10.1080/26896583.2020.1738161] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are hepatotoxic, genotoxic, and carcinogenic phytochemicals. Upon metabolic activation, PAs produce dehydropyrrolizidine alkaloids (dehydro-PAs) as reactive primary pyrrolic metabolites. Dehydro-PAs are unstable, facilely hydrolyzed to (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP). Both dehydro-PAs and DHP are capable of binding to cellular DNA and proteins to form DHP-DNA and DHP-protein adducts leading to tumorigenicity and cytotoxicity. We recently determined that the reaction of dehydro-PAs with glutathione and cysteine generated 7-glutathione-DHP (7-GS-DHP) and 7-cysteine-DHP, respectively which can also bind to DNA to produce DHP-DNA adducts. In this study, we determined the effects of glutathione and cysteine on the induction of hepatocytotoxicity and the formation of DHP-DNA adducts in primary hepatocytes cultured with riddelliine and monocrotaline. We found that both glutathione and cysteine can drastically reduce hepatotoxicity while the levels of DHP-DNA adduct formation are slightly affected.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, USA
| | - Qingsu Xia
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, USA
| | - Qiang Shi
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, USA
| | - Peter P Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, USA
| |
Collapse
|
8
|
Xia Q, He X, Shi Q, Lin G, Fu PP. Quantitation of DNA reactive pyrrolic metabolites of senecionine – A carcinogenic pyrrolizidine alkaloid by LC/MS/MS analysis. J Food Drug Anal 2020; 28:167-174. [DOI: 10.1016/j.jfda.2019.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
|
9
|
In vitro metabolism of pyrrolizidine alkaloids - Metabolic degradation and GSH conjugate formation of different structure types. Food Chem Toxicol 2019; 135:110868. [PMID: 31586656 DOI: 10.1016/j.fct.2019.110868] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 09/30/2019] [Accepted: 10/02/2019] [Indexed: 01/27/2023]
Abstract
Pyrrolizidine alkaloid (PA) forming plants are found worldwide and may contaminate food products at levels being of concern for human health. Due to the high biodiversity of PA producing plants many different types of PA structures are formed. PAs themselves are not toxic but require metabolic activation to exert toxicity. To investigate if the structure of the PAs affects their in vitro metabolism, we incubated a set of 22 PAs and compared the degradation rates and the amount of formed glutathione (GSH) conjugates. With human liver microsomes, no metabolic degradation of monoesters was found. Degradation rates of diester PAs tended to correlate with their hydrophilicity, whereby the more polar and branched-chained PAs exhibited lower degradation. There was a trend towards higher degradation rates in the presence of rat liver microsomes, but the GSH conjugate levels were similar. Although an effective degradation seems to be related with high GSH conjugate levels, no clear correlation between both parameters could be deduced. For both species no GSH conjugates, or only trace amounts, were formed from monoesters. However, for both open-chained as well as cyclic diesters GSH conjugates were detected and determined levels were comparable for both ester types without major structure-dependent differences.
Collapse
|
10
|
Khojasteh SC, Bumpus NN, Driscoll JP, Miller GP, Mitra K, Rietjens IMCM, Zhang D. Biotransformation and bioactivation reactions - 2018 literature highlights. Drug Metab Rev 2019; 51:121-161. [PMID: 31170851 DOI: 10.1080/03602532.2019.1615937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In the past three decades, ADME sciences have become an integral component of the drug discovery and development process. At the same time, the field has continued to evolve, thus, requiring ADME scientists to be knowledgeable of and engage with diverse aspects of drug assessment: from pharmacology to toxicology, and from in silico modeling to in vitro models and finally in vivo models. Progress in this field requires deliberate exposure to different aspects of ADME; however, this task can seem daunting in the current age of mass information. We hope this review provides a focused and brief summary of a wide array of critical advances over the past year and explains the relevance of this research ( Table 1 ). We divided the articles into categories of (1) drug optimization, (2) metabolites and drug metabolizing enzymes, and (3) bioactivation. This annual review is the fourth of its kind (Baillie et al. 2016 ; Khojasteh et al. 2017 , 2018 ). We have followed the same format we used in previous years in terms of the selection of articles and the authoring of each section. This effort in itself also continues to evolve. I am pleased that Rietjens, Miller, and Mitra have again contributed to this annual review. We would like to welcome Namandjé N. Bumpus, James P. Driscoll, and Donglu Zhang as authors for this year's issue. We strive to maintain a balance of authors from academic and industry settings. We would be pleased to hear your opinions of our commentary, and we extend an invitation to anyone who would like to contribute to a future edition of this review. Cyrus Khojasteh, on behalf of the authors.
Collapse
Affiliation(s)
- S Cyrus Khojasteh
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc , South San Francisco , CA , USA
| | - Namandjé N Bumpus
- Department of Medicine - Division of Clinical Pharmacology, The Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - James P Driscoll
- Department of Drug Metabolism and Pharmacokinetics, MyoKardia Inc. , South San Francisco , CA , USA
| | - Grover P Miller
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Kaushik Mitra
- Department of Safety Assessment and Laboratory Animal Resources, Merck Research Laboratories (MRL), Merck & Co., Inc , West Point , PA , USA
| | | | - Donglu Zhang
- Department of Drug Metabolism and Pharmacokinetics, Genentech Inc , South San Francisco , CA , USA
| |
Collapse
|
11
|
He X, Xia Q, Gamboa da Costa G, Lin G, Fu PP. 1-Formyl-7-hydroxy-6,7-dihydro-5 H-pyrrolizine (1-CHO-DHP): A Potential Proximate Carcinogenic Metabolite of Pyrrolizidine Alkaloids. Chem Res Toxicol 2019; 32:1193-1203. [PMID: 31120748 DOI: 10.1021/acs.chemrestox.9b00038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyrrolizidine alkaloids (PAs) are phytochemicals present in more than 6000 plant species worldwide; about half of the PAs are hepatotoxic, genotoxic, and carcinogenic. Because of their wide exposure and carcinogenicity, the International Programme on Chemical Safety (IPCS) concluded that PAs are a threat to human health and safety. We recently determined that PA-induced liver tumor initiation is mediated by a set of four (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5 H-pyrrolizine (DHP)-DNA adducts and proposed that these DHP-DNA adducts are biomarkers of PA exposure and liver tumor initiation. To validate the generality of this metabolic activation pathway and DHP-DNA adducts as biomarkers, it is significant to identify reactive metabolites associated with this metabolic activation pathway. Segall et al. ( Segall et al. ( 1984 ) Drug Metab. Dispos. 12 , 68 - 71 ) previously reported that 1-formyl-7-hydroxy-6,7-dihydro-5 H-pyrrolizine (1-CHO-DHP) is generated from the metabolism of senecionine by mouse liver microsomes. In the present study, we examined the metabolism of seven hepatocarcinogenic PAs (senecionine, intermedine, retrorsine, riddelliine, DHR, heliotrine, and senkirkine) and one noncarcinogenic PA (platyphylline) by human, rat, and mouse liver microsomes. 1-CHO-DHP was identified as a common metabolite from the metabolism of these hepatotoxic PAs, but not from platyphylline. Incubation of 1-CHO-DHP with HepG2 and A549 cells produced the same set of DHP-DNA adducts, which were identified by both LC/MS MRM mode and selected ion monitoring analyses through comparison to synthetic standards. In the incubation medium of 1-CHO-DHP treated HepG2 cells, both DHP and 7-cysteine-DHP were formed, which were capable of binding to cellular DNA to produce DHP-DNA adducts. These results suggest that 1-CHO-DHP is a proximate DNA metabolite of genotoxic and carcinogenic PAs.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research , U.S. Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Qingsu Xia
- National Center for Toxicological Research , U.S. Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Gonçalo Gamboa da Costa
- National Center for Toxicological Research , U.S. Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine , The Chinese University of Hong Kong , Hong Kong
| | - Peter P Fu
- National Center for Toxicological Research , U.S. Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| |
Collapse
|
12
|
Ebmeyer J, Braeuning A, Glatt H, These A, Hessel-Pras S, Lampen A. Human CYP3A4-mediated toxification of the pyrrolizidine alkaloid lasiocarpine. Food Chem Toxicol 2019; 130:79-88. [PMID: 31103741 DOI: 10.1016/j.fct.2019.05.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 05/08/2019] [Accepted: 05/13/2019] [Indexed: 01/05/2023]
Abstract
Pyrrolizidine alkaloids (PA) are widely distributed phytotoxins contaminating food and feed. Hepatic enzymes are considered to bioactivate PA. Previous studies showed differences in the metabolism rate in liver homogenates of different species. Thus, uncertainty remains with respect to the relevance of human metabolism. Our study aimed to analyze whether the PA representative lasiocarpine is toxified by human cytochrome P450 (CYP) enzymes. We compared the metabolic elimination of lasiocarpine in the presence of rat and human S9 fractions and liver microsomes. Experiments with the potent CYP3A/Cyp3a inhibitor ketoconazole and supersomes containing individual human and rat CYPs revealed that enzymes of the CYP3A/Cyp3a family of both species are of major relevance for lasiocarpine metabolism. To assess if metabolism by human CYP3A4 results in a toxification of lasiocarpine we performed experiments with V79 cells. γH2AX and micronucleus formation were analyzed as endpoints for genotoxicity. No effects were observed in the wildtype cells, which lack CYP activity. By contrast, a V79 clone engineered for expression of human CYP3A4 showed concentration-dependent γH2AX and micronucleus formation. Concluding, our results showed the CYP3A4-dependent formation of genotoxic metabolites of lasiocarpine. The results confirm previous data indicating the need to include metabolism of PA for human risk assessment.
Collapse
Affiliation(s)
- Johanna Ebmeyer
- German Federal Institute for Risk Assessment, Department Food Safety, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Albert Braeuning
- German Federal Institute for Risk Assessment, Department Food Safety, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Hansruedi Glatt
- German Federal Institute for Risk Assessment, Department Food Safety, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Anja These
- German Federal Institute for Risk Assessment, Department Safety in the Food Chain, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| | - Stefanie Hessel-Pras
- German Federal Institute for Risk Assessment, Department Food Safety, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany.
| | - Alfonso Lampen
- German Federal Institute for Risk Assessment, Department Food Safety, Max-Dohrn-Straße 8-10, 10589, Berlin, Germany
| |
Collapse
|
13
|
Budhani S, Egboluche NP, Arslan Z, Yu H, Deng H. Phytotoxic effect of silver nanoparticles on seed germination and growth of terrestrial plants. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2019; 37:330-355. [PMID: 31661365 PMCID: PMC7773158 DOI: 10.1080/10590501.2019.1676600] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Silver nanoparticles (AgNP) exhibit size and concentration dependent toxicity to terrestrial plants, especially crops. AgNP exposure could decrease seed germination, inhibit seedling growth, affect mass and length of roots and shoots. The phytotoxic pathway has been partly understood. Silver (as element, ion or AgNP) accumulates in roots/leaves and triggers the defense mechanism at cellular and tissue levels, which alters metabolism, antioxidant activities and related proteomic expression. Botanical changes (either increase or decrease) in response to AgNP exposure include reactive oxygen species generation, superoxide dismutase activities, H2O2 level, total chlorophyll, proline, carotenoid, ascorbate and glutathione contents, etc. Such processes lead to abnormal morphological changes, suppression of photosynthesis and/or transpiration, and other symptoms. Although neutral or beneficial effects are also reported depending on plant species, adverse effects dominate in majority of the studies. More in depth research is needed to confidently draw any conclusions and to guide legislation and regulations.
Collapse
Affiliation(s)
- Shruti Budhani
- Department of Chemistry, School of Computer, Mathematical and Natural Sciences, Morgan State University, Baltimore, MD, USA
| | - Nzube Prisca Egboluche
- Department of Chemistry, School of Computer, Mathematical and Natural Sciences, Morgan State University, Baltimore, MD, USA
| | - Zikri Arslan
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS, USA
| | - Hongtao Yu
- Department of Chemistry, School of Computer, Mathematical and Natural Sciences, Morgan State University, Baltimore, MD, USA
| | - Hua Deng
- Department of Chemistry, School of Computer, Mathematical and Natural Sciences, Morgan State University, Baltimore, MD, USA
| |
Collapse
|
14
|
He X, Xia Q, Wu Q, Tolleson WH, Lin G, Fu PP. Primary and secondary pyrrolic metabolites of pyrrolizidine alkaloids form DNA adducts in human A549 cells. Toxicol In Vitro 2018; 54:286-294. [PMID: 30366057 DOI: 10.1016/j.tiv.2018.10.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 09/14/2018] [Accepted: 10/19/2018] [Indexed: 10/28/2022]
Abstract
Humans and animals can be exposed to carcinogenic pyrrolizidine alkaloids (PAs) through consumption of plants commonly found in many parts of the world. Although the liver is the primary target organ for carcinogenic PAs, they have also induced lung tumors in rodents. Hepatic cytochrome P450 activity converts PAs into dehydro-PAs that can be hydrolyzed to dehydropyrrolizidine (DHP); these reactive pyrrolic metabolites can produce four characteristic DNA adducts associated with PA-induced liver tumor initiation in laboratory animals. We reported recently that these four DNA adducts are also formed when 7-glutathione-DHP (7-GS-DHP) or 7-cysteine-DHP is incubated with calf thymus DNA. Here we showed that the four characteristic DNA adducts were formed when human A549 brochoalveolar carcinoma cells were treated with three dehydro-PAs (dehydroriddelliine, dehydromonocrotaline, or dehydroretronecine) or with 7-GS-DHP or 7-cysteine-DHP. For comparison, two parent PAs (riddelliine and monocrotaline) and 7,9-di-glutathionine-DHP were studied. No DHP-DNA adducts were detected with these incubations, confirming that A549 lung carcinoma cells do not express cytochrome P450 enzymes required for metabolic activation of PAs. Our results show that primary and secondary pyrrolic metabolites of carcinogenic PAs produce characteristic DHP-containing DNA adducts in A549 lung cancer cells, suggesting that they are DNA reactive metabolites.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Qingsu Xia
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Qiangen Wu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - William H Tolleson
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
| | - Peter P Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, USA.
| |
Collapse
|
15
|
Ma C, Liu Y, Zhu L, Ji H, Song X, Guo H, Yi T. Determination and regulation of hepatotoxic pyrrolizidine alkaloids in food: A critical review of recent research. Food Chem Toxicol 2018; 119:50-60. [DOI: 10.1016/j.fct.2018.05.037] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/11/2018] [Accepted: 05/13/2018] [Indexed: 11/26/2022]
|
16
|
Ma J, Xia Q, Fu PP, Lin G. Pyrrole-protein adducts - A biomarker of pyrrolizidine alkaloid-induced hepatotoxicity. J Food Drug Anal 2018; 26:965-972. [PMID: 29976414 PMCID: PMC9303027 DOI: 10.1016/j.jfda.2018.05.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 05/30/2018] [Indexed: 12/11/2022] Open
Abstract
Pyrrolizidine alkaloids (PAs) are phytotoxins identified in over 6000 plant species worldwide. Approximately 600 toxic PAs and PA N-oxides have been identified in about 3% flowering plants. PAs can cause toxicities in different organs particularly in the liver. The metabolic activation of PAs is catalyzed by hepatic cytochrome P450 and generates reactive pyrrolic metabolites that bind to cellular proteins to form pyrrole-protein adducts leading to PA-induced hepatotoxicity. The mechanisms that pyrrole-protein adducts induce toxicities have not been fully characterized. Methods for qualitative and quantitative detection of pyrrole-protein adducts have been developed and applied for the clinical diagnosis of PA exposure and PA-induced liver injury. This mini-review addresses the mechanisms of PA-induced hepatotoxicity mediated by pyrrole-protein adducts, the analytical methods for the detection of pyrrole-protein adducts, and the development of pyrrole-protein adducts as the mechanism-based biomarker of PA exposure and PA-induced hepatotoxicity.
Collapse
Affiliation(s)
- Jiang Ma
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China; Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines Between the Chinese University of Hong Kong and Shanghai Institute of Materia Medica, China Academy of Sciences, China
| | - Qingsu Xia
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA
| | - Peter P Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR, 72079, USA.
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China; Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines Between the Chinese University of Hong Kong and Shanghai Institute of Materia Medica, China Academy of Sciences, China.
| |
Collapse
|
17
|
Xia Q, He X, Ma L, Chen S, Fu PP. Pyrrolizidine Alkaloid Secondary Pyrrolic Metabolites Construct Multiple Activation Pathways Leading to DNA Adduct Formation and Potential Liver Tumor Initiation. Chem Res Toxicol 2018; 31:619-628. [PMID: 29855181 DOI: 10.1021/acs.chemrestox.8b00096] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Pyrrolizidine alkaloids (PAs) and their N-oxide derivatives are hepatotoxic, genotoxic, and carcinogenic phytochemicals. PAs induce liver tumors through a general genotoxic mechanism mediated by a set of four (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5 H-pyrrolizine (DHP)-derived DNA adducts. To date, the primary pyrrolic metabolites dehydro-PAs, their hydrolyzed metabolite DHP, and two secondary pyrrolic metabolites 7-glutathione-DHP (7-GS-DHP) and 7-cysteine-DHP are the known metabolites that can generate these DHP-DNA adducts in vivo and/or in PA-treated cells. Secondary pyrrolic metabolites are formed from the reaction of dehydro-PAs with glutathione, amino acids, and proteins. In this investigation, we determined whether or not more secondary pyrrolic metabolites can bind to calf thymus DNA and to cellular DNA in HepG2 cells resulting in the formation of DHP-DNA adducts using a series of secondary pyrrolic metabolites (including 7-methoxy-DHP, 9-ethoxy-DHP, 9-valine-DHP, 7-GS-DHP, 7-cysteine-DHP, and 7,9-diglutathione-DHP) and synthetic pyrroles for study. We found that (i) many secondary pyrrolic metabolites are DNA reactive and can form DHP-DNA adducts and (ii) multiple activation pathways are involved in producing DHP-DNA adducts associated with PA-induced liver tumor initiation. These results suggest that secondary pyrrolic metabolites play a vital role in the initiation of PA-induced liver tumors.
Collapse
Affiliation(s)
- Qingsu Xia
- National Center for Toxicological Research , Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Xiaobo He
- National Center for Toxicological Research , Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Liang Ma
- National Center for Toxicological Research , Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Shoujun Chen
- National Center for Toxicological Research , Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Peter P Fu
- National Center for Toxicological Research , Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| |
Collapse
|
18
|
Prinsloo G, Nogemane N, Street R. The use of plants containing genotoxic carcinogens as foods and medicine. Food Chem Toxicol 2018; 116:27-39. [DOI: 10.1016/j.fct.2018.04.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 03/28/2018] [Accepted: 04/03/2018] [Indexed: 01/20/2023]
|
19
|
Li YH, Tai WCS, Khan I, Lu C, Lu Y, Wong WY, Chan WY, Wendy Hsiao WL, Lin G. Toxicoproteomic assessment of liver responses to acute pyrrolizidine alkaloid intoxication in rats. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2018; 36:65-83. [PMID: 29667502 DOI: 10.1080/10590501.2018.1450186] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A toxicoproteomic study was performed on liver of rats treated with retrorsine (RTS), a representative hepatotoxic pyrrolizidine alkaloid at a toxic dose (140 mg/kg) known to cause severe acute hepatotoxicity. By comparing current data with our previous findings in mild liver lesions of rats treated with a lower dose of RTS, seven proteins and three toxicity pathways of vascular endothelial cell death, which was further verified by observed sinusoidal endothelial cell losses, were found uniquely associated with retrorsine-induced hepatotoxicity. This toxicoproteomic study of acute pyrrolizidine alkaloid intoxication lays a foundation for future investigation to delineate molecular mechanisms of pyrrolizidine alkaloid-induced hepatotoxicity.
Collapse
Affiliation(s)
- Yan-Hong Li
- a School of Biomedical Sciences, Faculty of Medicine , The Chinese University of Hong Kong , Hong Kong SAR, China
- b School of Medicine , South China University of Technology , Guangzhou , China
| | - William Chi-Shing Tai
- c Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hong Kong SAR, China
| | - Imran Khan
- d State Key Laboratory of Quality Research in Chinese Medicines , Macau University of Science and Technology , Macau SAR, China
| | - Cheng Lu
- e Institute of Basic Research in Clinical Medicine , China Academic of Chinese Medical Sciences , Beijing , China
| | - Yao Lu
- a School of Biomedical Sciences, Faculty of Medicine , The Chinese University of Hong Kong , Hong Kong SAR, China
| | - Wing-Yan Wong
- c Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hong Kong SAR, China
| | - Wood-Yee Chan
- a School of Biomedical Sciences, Faculty of Medicine , The Chinese University of Hong Kong , Hong Kong SAR, China
| | - Wen-Luan Wendy Hsiao
- d State Key Laboratory of Quality Research in Chinese Medicines , Macau University of Science and Technology , Macau SAR, China
| | - Ge Lin
- a School of Biomedical Sciences, Faculty of Medicine , The Chinese University of Hong Kong , Hong Kong SAR, China
| |
Collapse
|
20
|
He X, Xia Q, Woodling K, Lin G, Fu PP. Pyrrolizidine alkaloid-derived DNA adducts are common toxicological biomarkers of pyrrolizidine alkaloid N-oxides. J Food Drug Anal 2017; 25:984-991. [PMID: 28987376 PMCID: PMC9328871 DOI: 10.1016/j.jfda.2017.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
There are 660 pyrrolizidine alkaloids (PAs) and PA N-oxides present in the plants, with approximately half being possible carcinogens. We previously reported that a set of four PA-derived DNA adducts is formed in the liver of rats administered a series of hepatocarcinogenic PAs and a PA N-oxide. Based on our findings, we hypothesized that this set of DNA adducts is a common biological biomarker of PA-induced liver tumor formation. In this study, we determined that rat liver microsomal metabolism of five hepatocarcinogenic PAs (lasiocarpine, retrorsine, riddelliine, monocrotaline, and heliotrine) and their corresponding PA N-oxides produced the same set of DNA adducts. Among these compounds, lasiocarpine N-oxide, retrorsine N-oxide, monocrotaline N-oxide, and heliotrine N-oxide are for first time shown to be able to produce these DNA adducts. These results further support the role of these DNA adducts as potential common biomarkers of PA-induced liver tumor initiation.
Collapse
Affiliation(s)
- Xiaobo He
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079,
United States
| | - Qingsu Xia
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079,
United States
| | - Kellie Woodling
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079,
United States
| | - Ge Lin
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong,
Hong Kong
| | - Peter P. Fu
- National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079,
United States
- Corresponding author. Fax: +1 870 543 7136. E-mail address: (P.P. Fu)
| |
Collapse
|