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Mashayekhi-Sardoo H, Rezaee R, Riahi-Zanjani B, Karimi G. Alleviation of microcystin-leucine arginine -induced hepatotoxicity: An updated overview. Toxicon 2024; 243:107715. [PMID: 38636613 DOI: 10.1016/j.toxicon.2024.107715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 04/04/2024] [Accepted: 04/09/2024] [Indexed: 04/20/2024]
Abstract
OBJECTIVES Contamination of surface waters is a major health threat for all living creatures. Some types of blue-green algae that naturally occur in fresh water, are able to produce various toxins, like Microcystins (MCs). Microcystin-leucine arginine (MC-LR) produced by Microcystis aeruginosa is the most toxic and abundant isoforms of MCs, and it causes hepatotoxicity. The present article reviews preclinical experiments examined different treatments, including herbal derivatives, dietary supplements and drugs against MC-LR hepatotoxicity. METHODS We searched scientific databases Web of Science, Embase, Medline (PubMed), Scopus, and Google Scholar using relevant keywords to find suitable studies until November 2023. RESULTS MC-LR through Organic anion transporting polypeptide superfamily transporters (OATPs) penetrates and accumulates in hepatocytes, and it inhibits protein phosphatases (PP1 and PP2A). Consequently, MC-LR disturbs many signaling pathways and induces oxidative stress thus damages cellular macromolecules. Some protective agents, especially plants rich in flavonoids, and natural supplements, as well as chemoprotectants were shown to diminish MC-LR hepatotoxicity. CONCLUSION The reviewed agents through blocking the OATP transporters (nontoxic nostocyclopeptide-M1, captopril, and naringin), then inhibition of MC-LR uptake (naringin, rifampin, cyclosporin-A, silymarin and captopril), and finally at restoration of PPAse activity (silybin, quercetin, morin, naringin, rifampin, captopril, azo dyes) exert hepatoprotective effect against MC-LR.
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Affiliation(s)
- Habibeh Mashayekhi-Sardoo
- Bio Environmental Health Hazard Research Center, Jiroft University of Medical Sciences, Jiroft, Iran; Jiroft University of Medical Sciences, Jiroft, Iran.
| | - Ramin Rezaee
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Bamdad Riahi-Zanjani
- Medical Toxicology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Gholamreza Karimi
- Pharmaceutical Research Center, Institute of Pharmaceutical Technology, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
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Liu YL, Liu JY, Zhu XX, Wei JH, Mi SL, Liu SY, Li XL, Zhang WW, Zhao LL, Wang H, Xu DX, Gao L. Pubertal exposure to Microcystin-LR arrests spermatogonia proliferation by inducing DSB and inhibiting SIRT6 dependent DNA repair in vivo and in vitro. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 274:116191. [PMID: 38460408 DOI: 10.1016/j.ecoenv.2024.116191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 02/28/2024] [Accepted: 03/06/2024] [Indexed: 03/11/2024]
Abstract
The reproduction toxicity of pubertal exposure to Microcystin-LR (MC-LR) and the underlying mechanism needs to be further investigated. In the current study, pubertal male ICR mice were intraperitoneally injected with 2 μg/kg MC-LR for four weeks. Pubertal exposure to MC-LR decreased epididymal sperm concentration and blocked spermatogonia proliferation. In-vitro studies found MC-LR inhibited cell proliferation of GC-1 cells and arrested cell cycle in G2/M phase. Mechanistically, MC-LR exposure evoked excessive reactive oxygen species (ROS) and induced DNA double-strand break in GC-1 cells. Besides, MC-LR inhibited DNA repair by reducing PolyADP-ribosylation (PARylation) activity of PARP1. Further study found MC-LR caused proteasomal degradation of SIRT6, a monoADP-ribosylation enzyme which is essential for PARP1 PARylation activity, due to destruction of SIRT6-USP10 interaction. Additionally, MG132 pretreatment alleviated MC-LR-induced SIRT6 degradation and promoted DNA repair, leading to the restoration of cell proliferation inhibition. Correspondingly, N-Acetylcysteine (NAC) pre-treatment mitigated the disturbed SIRT6-USP10 interaction and SIRT6 degradation, causing recovered DNA repair and subsequently restoration of cell proliferation inhibition in MC-LR treated GC-1 cells. Together, pubertal exposure to MC-LR induced spermatogonia cell cycle arrest and sperm count reduction by oxidative DNA damage and simultaneous SIRT6-mediated DNA repair failing. This study reports the effect of pubertal exposure to MC-LR on spermatogenesis and complex mechanism how MC-LR induces spermatogonia cell proliferation inhibition.
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Affiliation(s)
- Yu-Lin Liu
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Jia-Yu Liu
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Xin-Xin Zhu
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Jian-Hua Wei
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Shuang-Ling Mi
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Su-Ya Liu
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Xiu-Liang Li
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Wei-Wei Zhang
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Ling-Li Zhao
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Hua Wang
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China
| | - De-Xiang Xu
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China.
| | - Lan Gao
- Key Laboratory of Environmental Toxicology of Anhui Higher Education Institutes & Department of Toxicology, School of Public Health, Anhui Medical University, Hefei 230032, China; Research Center for Translational Medicine, the Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230601, China.
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3
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Du X, Fu Y, Tian Z, Liu H, Xin H, Fu X, Wang F, Zhang H, Zeng X. Microcystin-LR accelerates follicular atresia in mice via JNK-mediated adherent junction damage of ovarian granulosa cells. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 252:114592. [PMID: 36731181 DOI: 10.1016/j.ecoenv.2023.114592] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 01/25/2023] [Accepted: 01/29/2023] [Indexed: 06/18/2023]
Abstract
Microcystin-LR (MC-LR), one of aquatic environmental contaminants with reproductive toxicity produced by cyanobacterial blooms, but its toxic effects and mechanisms on the ovary are not fully understood. Here, proteomic techniques and molecular biology experiments were performed to study the potential mechanism of MC-LR-caused ovarian toxicity. Results showed that protein expression profile of ovarian granulosa cells (KK-1) was changed by 17 μg/mL MC-LR exposure. Comparing with the control group, 118 upregulated proteins as well as 97 downregulated proteins were identified in MC-LR group. Function of differentially expressed proteins was found to be enriched in pathways related to adherent junction, such as cadherin binding, cell-cell junction, cell adhesion and focal adherens. Furthermore, in vitro experiments, MC-LR significantly downregulated the expression levels of proteins associated with adherent junction (β-catenin, N-cadherin, and α-catenin) as well as caused cytoskeletal disruption in KK-1 cells (P < 0.05), indicating that the adherent junction was damaged. Results of in vivo experiments have shown that after 14 days of acute MC-LR exposure (40 μg/kg), damaged adherent junction and an increased number of atretic follicles were observed in mouse ovaries. Moreover, MC-LR activated JNK, an upstream regulator of adherent junction proteins, in KK-1 cells and mouse ovarian tissues. In contrast, JNK inhibition alleviated MC-LR-induced adherent junction damage in vivo and in vitro, as well as the number of atretic follicles. Taken together, findings from the present study indicated that JNK is involved in MC-LR-induced granulosa cell adherent junction damage, which accelerated follicular atresia. Our study clarified a novel mechanism of MC-LR-caused ovarian toxicity, providing a theoretical foundation for protecting female reproductive health from environmental pollutants.
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Affiliation(s)
- Xingde Du
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China
| | - Yu Fu
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China
| | - Zhihui Tian
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China
| | - Haohao Liu
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China
| | - Hongxia Xin
- Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital, Zhengzhou 450003, China
| | - Xiaoli Fu
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China
| | - Fufang Wang
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China.
| | - Xin Zeng
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China.
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Ait Abderrahim L, Taibi K, Boussaid M, Al-Shara B, Ait Abderrahim N, Ait Abderrahim S. Allium sativum mitigates oxidative damages induced by Microcystin-LR in heart and liver tissues of mice. Toxicon 2021; 200:30-37. [PMID: 34217748 DOI: 10.1016/j.toxicon.2021.06.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 06/27/2021] [Accepted: 06/30/2021] [Indexed: 10/20/2022]
Abstract
Microcystins (MCs) are hepatotoxic cyanotoxins implicated in several incidents of human and animal toxicity. Microcystin-(Lysine, Arginine) or MC-LR is the most toxic and encountered variant of MCs where oxidative stress plays a key role in its toxicity. This study investigated the oxidative damages induced in the liver and heart of Balb/C mice by an intraperitoneal injected acute dose of MC-LR. Thereafter, the potential protective effect of garlic (Allium sativum) extract supplementation against such damages was assessed through the evaluation of oxidative stress and cytotoxicity markers. Lipid peroxidation (LPO), carbonyl content (CC), glutathione content (GSH), alkaline phosphatase activity (ALP), lactate dehydrogenase (LDH) and sorbitol dehydrogenase (SDH) activities were measured. Results showed important oxidative damages in hepatic and cardiac cells of mice injected with the toxin. However, these damages have been significantly reduced in mice supplemented with garlic extract. Thus, this study demonstrated for the first time the effective use of garlic as an antioxidant agent against oxidative damages induced by MC-LR. As well, this study supports the use of garlic as a potential remedy against pathologies related to toxic agents.
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Affiliation(s)
- Leila Ait Abderrahim
- Faculty of Life and Natural Sciences, Ibn Khaldoun University, Karman Campus, 14000, Tiaret, Algeria.
| | - Khaled Taibi
- Faculty of Life and Natural Sciences, Ibn Khaldoun University, Karman Campus, 14000, Tiaret, Algeria
| | - Mohamed Boussaid
- Faculty of Life and Natural Sciences, Ibn Khaldoun University, Karman Campus, 14000, Tiaret, Algeria
| | - Baker Al-Shara
- Institute of Biological Sciences, Faculty of Science, University Malaya, Kuala Lumpur, 50603, Malaysia
| | | | - Sabrina Ait Abderrahim
- Faculty of Life and Natural Sciences, Ibn Khaldoun University, Karman Campus, 14000, Tiaret, Algeria
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Gu L, Li S, Bai J, Zhang Q, Han Z. α-Lipoic acid protects against microcystin-LR induced hepatotoxicity through regeneration of glutathione via activation of Nrf2. ENVIRONMENTAL TOXICOLOGY 2020; 35:738-746. [PMID: 32061150 DOI: 10.1002/tox.22908] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/10/2020] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Microcystins (MCs), as the most dominant bloom-forming strains in eutrophic surface water, can induce hepatotoxicity by oxidative stress. Alpha-lipoic acid (α-LA) is a super antioxidant that can induce the synthesis of antioxidants, such as glutathione (GSH), by nuclear factor erythroid 2-related factor 2 (Nrf2). However, the potential molecular mechanism of α-LA regeneration of GSH remains unclear. The present study aimed to investigate whether α-LA could reduce the toxicity of MCs induced in human hepatoma (HepG2), Bel7420 cells, and BALB/c mice by activating Nrf2 to regenerate GSH. Results showed that exposure to 10 μM microcystin-leucine arginine (MC-LR) reduced viability of HepG2 and Bel7402 cells and promoted the formation of reactive oxygen species (ROS) compared with untreated cells. Moreover, the protection of α-LA included reducing the level of ROS, increasing superoxide dismutase activity, and decreasing malondialdehyde. Levels of reduced glutathione (rGSH) and rGSH/oxidized glutathione were significantly increased in cells cotreated with α-LA and MC-LR compared to those treated with MC-LR alone, indicating an ability of α-LA to attenuate oxidative stress and MC-LR-induced cytotoxicity by increasing the amount of rGSH. α-LA can mediate GSH regeneration through the Nrf2 pathway under the action of glutathione reductase in MC-LR cell lines. Furthermore, the data also showed that α-LA-induced cytoprotection against MC-LR is associated with Nrf2 mediate pathway in vivo. These findings demonstrated the potential of α-LA to resist MC-LR-induced oxidative damage of liver.
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Affiliation(s)
- Lihong Gu
- Department of labor hygiene and environmental hygiene, School of Public Health, Southwest Medical University, Luzhou, Sichuan, China
| | - Shangchun Li
- Department of labor hygiene and environmental hygiene, School of Public Health, Southwest Medical University, Luzhou, Sichuan, China
| | - Jun Bai
- Department of labor hygiene and environmental hygiene, School of Public Health, Southwest Medical University, Luzhou, Sichuan, China
| | - Qingbi Zhang
- Department of labor hygiene and environmental hygiene, School of Public Health, Southwest Medical University, Luzhou, Sichuan, China
| | - Zhixia Han
- Department of labor hygiene and environmental hygiene, School of Public Health, Southwest Medical University, Luzhou, Sichuan, China
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6
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Tamele IJ, Vasconcelos V. Microcystin Incidence in the Drinking Water of Mozambique: Challenges for Public Health Protection. Toxins (Basel) 2020; 12:E368. [PMID: 32498435 PMCID: PMC7354522 DOI: 10.3390/toxins12060368] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 05/29/2020] [Accepted: 05/31/2020] [Indexed: 11/28/2022] Open
Abstract
Microcystins (MCs) are cyanotoxins produced mainly by freshwater cyanobacteria, which constitute a threat to public health due to their negative effects on humans, such as gastroenteritis and related diseases, including death. In Mozambique, where only 50% of the people have access to safe drinking water, this hepatotoxin is not monitored, and consequently, the population may be exposed to MCs. The few studies done in Maputo and Gaza provinces indicated the occurrence of MC-LR, -YR, and -RR at a concentration ranging from 6.83 to 7.78 µg·L-1, which are very high, around 7 times above than the maximum limit (1 µg·L-1) recommended by WHO. The potential MCs-producing in the studied sites are mainly Microcystis species. These data from Mozambique and from surrounding countries (South Africa, Lesotho, Botswana, Malawi, Zambia, and Tanzania) evidence the need to implement an operational monitoring program of MCs in order to reduce or avoid the possible cases of intoxications since the drinking water quality control tests recommended by the Ministry of Health do not include an MC test. To date, no data of water poisoning episodes recorded were associated with MCs presence in the water. However, this might be underestimated due to a lack of monitoring facilities and/or a lack of public health staff trained for recognizing symptoms of MCs intoxication since the presence of high MCs concentration was reported in Maputo and Gaza provinces.
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Affiliation(s)
- Isidro José Tamele
- CIIMAR/CIMAR—Interdisciplinary Center of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto, Avenida General Norton de Matos, 4450-238 Matosinhos, Portugal;
- Institute of Biomedical Science Abel Salazar, University of Porto, R. Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal
- Department of Chemistry, Faculty of Sciences, Eduardo Mondlane University, Av. Julius Nyerere, n 3453, Campus Principal, Maputo 257, Mozambique
| | - Vitor Vasconcelos
- CIIMAR/CIMAR—Interdisciplinary Center of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto, Avenida General Norton de Matos, 4450-238 Matosinhos, Portugal;
- Faculty of Science, University of Porto, Rua do Campo Alegre, 4069-007 Porto, Portugal
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Pan D, Pavagadhi S, Umashankar S, Rai A, Benke PI, Rai M, Saxena G, Gangu V, Swarup S. Resource partitioning strategies during toxin production in Microcystis aeruginosa revealed by integrative omics analysis. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Cao L, Massey IY, Feng H, Yang F. A Review of Cardiovascular Toxicity of Microcystins. Toxins (Basel) 2019; 11:toxins11090507. [PMID: 31480273 PMCID: PMC6783932 DOI: 10.3390/toxins11090507] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 12/30/2022] Open
Abstract
The mortality rate of cardiovascular diseases (CVD) in China is on the rise. The increasing burden of CVD in China has become a major public health problem. Cyanobacterial blooms have been recently considered a global environmental concern. Microcystins (MCs) are the secondary products of cyanobacteria metabolism and the most harmful cyanotoxin found in water bodies. Recent studies provide strong evidence of positive associations between MC exposure and cardiotoxicity, representing a threat to human cardiovascular health. This review focuses on the effects of MCs on the cardiovascular system and provides some evidence that CVD could be induced by MCs. We summarized the current knowledge of the cardiovascular toxicity of MCs, with regard to direct cardiovascular toxicity and indirect cardiovascular toxicity. Toxicity of MCs is mainly governed by the increasing level of reactive oxygen species (ROS), oxidative stress in mitochondria and endoplasmic reticulum, the inhibition activities of serine/threonine protein phosphatase 1 (PP1) and 2A (PP2A) and the destruction of cytoskeletons, which finally induce the occurrence of CVD. To protect human health from the threat of MCs, this paper also puts forward some directions for further research.
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Affiliation(s)
- Linghui Cao
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha 410078, Hunan, China
| | - Isaac Yaw Massey
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha 410078, Hunan, China
| | - Hai Feng
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha 410078, Hunan, China
| | - Fei Yang
- Department of Occupational and Environmental Health, Xiangya School of Public Health, Central South University, Changsha 410078, Hunan, China.
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Shin EJ, Hwang YG, Pham DT, Lee JW, Lee YJ, Pyo D, Jeong JH, Lei XG, Kim HC. Glutathione peroxidase-1 overexpressing transgenic mice are protected from neurotoxicity induced by microcystin-leucine-arginine. ENVIRONMENTAL TOXICOLOGY 2018; 33:1019-1028. [PMID: 30076769 DOI: 10.1002/tox.22580] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/15/2018] [Accepted: 05/20/2018] [Indexed: 06/08/2023]
Abstract
Although it has been well-recognized that microcystin-leucine-arginine (MCLR), the most common form of microcystins, induces neurotoxicity, little is currently known about the underlying mechanism for this neurotoxicity. Here, we found that MCLR (10 ng/μL/mouse, i.c.v.) induces significant neuronal loss in the hippocampus of mice. MCLR-induced neurotoxicity was accompanied by oxidative stress, as shown by a significant increase in the level of 4-hydroxynonenal, protein carbonyl, and reactive oxygen species (ROS). Superoxide dismutase-1 (SOD-1) activity was significantly increased, but glutathione peroxidase (GPx) level was significantly decreased following MCLR insult. In addition, MCLR significantly inhibited GSH/GSSG ratio, and significantly induced NFκB DNA binding activity. Because reduced activity of GPx appeared to be critical for the imbalance between activities of SODs and GPx, we utilized GPx-1 overexpressing transgenic mice to ascertain the role of GPx-1 in this neurotoxicity. Genetic overexpression of GPx-1 or NFκB inhibitor pyrrolidine dithiocarbamate (PDTC) significantly attenuated MCLR-induced hippocampal neuronal loss in mice. However, PDTC did not exert any additive effect on neuroprotection mediated by GPx-1 overexpression, indicating that NFκB is a neurotoxic target of MCLR. Combined, these results suggest that MCLR-induced neurotoxicity requires oxidative stress associated with failure in compensatory induction of GPx, possibly through activation of the transcription factor NFκB.
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Affiliation(s)
- Eun-Joo Shin
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Yeong Gwang Hwang
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Duc Toan Pham
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Ji Won Lee
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Yu Jeung Lee
- Clinical Pharmacy, College of Pharmacy, Kangwon National University, Republic of Korea
| | - Dongjin Pyo
- Department of Chemistry, College of Natural Sciences, Kangwon National University, Republic of Korea
| | - Ji Hoon Jeong
- Department of Pharmacology, College of Medicine, Chung-Ang University, Seoul, Republic of Korea
| | - Xin Gen Lei
- Department of Animal Science, Cornell University, New York
| | - Hyoung-Chun Kim
- Neuropsychopharmacology and Toxicology Program, College of Pharmacy, Kangwon National University, Republic of Korea
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Scoglio S. Microcystins in water and in microalgae: Do microcystins as microalgae contaminants warrant the current public alarm? Toxicol Rep 2018; 5:785-792. [PMID: 30105209 PMCID: PMC6086208 DOI: 10.1016/j.toxrep.2018.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 07/08/2018] [Accepted: 07/24/2018] [Indexed: 12/31/2022] Open
Abstract
Microcystins have been the subject of increasingly alarming popular and scientific articles, which have taken as their unquestionable foundation the provisional Guideline of 1 μg/L established by the WHO Panel on microcystins levels in water, and mechanically translated by the Oregon government as 1 μg/g of Klamath Aphanizomenon flos aquae microalgae. This article underlines the significant limitations and ultimately scientific untenability of the WHO Guideline on microcystins in water, for being based on testing methodologies which may lead to a significant overestimation of the toxicity of microcystins. I propose criteria for the realization of new experimental studies on the toxicity of microcystins, based on the essential understanding that drinking water is contaminated by whole cyanobacterial microalgae rather than purified microcystins, while it is important to differentiate between water and cyanobacterial supplements. It is indeed a mistake to automatically apply standards that are proper for water to cyanobacterial supplements, as they have different concentrations of the antioxidant substances that inactivate or significantly reduce the toxicity of microcystins, a fact that also require that each cyanobacterial supplement be tested individually and through realistic testing methodologies.
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Myhre O, Eide DM, Kleiven S, Utkilen HC, Hofer T. Repeated five-day administration of L-BMAA, microcystin-LR, or as mixture, in adult C57BL/6 mice - lack of adverse cognitive effects. Sci Rep 2018; 8:2308. [PMID: 29396538 PMCID: PMC5797144 DOI: 10.1038/s41598-018-20327-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 01/17/2018] [Indexed: 12/23/2022] Open
Abstract
The cyanobacterial toxins β-methylamino-L-alanine (L-BMAA) and microcystin-LR (MC-LR; a potent liver toxin) are suspected to cause neurological disorders. Adult male C57BL/6JOlaHsd mice aged approximately 11 months were subcutaneously injected for five consecutive days with L-BMAA and microcystin-LR alone, or as a mixture. A dose-range study determined a tolerable daily dose to be ~31 µg MC-LR/kg BW/day based on survival, serum liver status enzymes, and relative liver and kidney weight. Mice tolerating the first one-two doses also tolerated the subsequent three-four doses indicating adaptation. The LD50 was 43-50 μg MC-LR/kg BW. Long-term effects (up to 10 weeks) on spatial learning and memory performance was investigated using a Barnes maze, were mice were given 30 µg MC-LR/kg BW and/or 30 mg L-BMAA/kg BW either alone or in mixture for five consecutive days. Anxiety, general locomotor activity, willingness to explore, hippocampal and peri-postrhinal cortex dependent memory was investigated after eight weeks using Open field combined with Novel location/Novel object recognition tests. Toxin exposed animals did not perform worse than controls, and MC-LR exposed animals performed somewhat better during the first Barnes maze re-test session. MC-LR exposed mice rapidly lost up to ~5% body weight, but regained weight from day eight.
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Affiliation(s)
- Oddvar Myhre
- Department of Toxicology and Risk Assessment, Norwegian Institute of Public Health (NIPH), Oslo, Norway
| | - Dag Marcus Eide
- Department of Toxicology and Risk Assessment, Norwegian Institute of Public Health (NIPH), Oslo, Norway
| | - Synne Kleiven
- Department of Natural Sciences and Environmental Health, University College of Southeast Norway, Bø, Norway
| | - Hans Christian Utkilen
- Department of Natural Sciences and Environmental Health, University College of Southeast Norway, Bø, Norway
| | - Tim Hofer
- Department of Toxicology and Risk Assessment, Norwegian Institute of Public Health (NIPH), Oslo, Norway.
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Augusti PR, Brasil AVS, Souto C, Göethel G, de Oliveira Rios A, Emanuelli T, Bürger ME, Garcia SC. Microcystin-LR exposure induces oxidative damage in Caenorhabditis elegans: Protective effect of lutein extracted from marigold flowers. Food Chem Toxicol 2017; 109:60-67. [PMID: 28866331 DOI: 10.1016/j.fct.2017.08.045] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/28/2017] [Accepted: 08/29/2017] [Indexed: 12/31/2022]
Abstract
Microcystin-LR (MIC-LR) is a hepatotoxin, with toxicity mechanisms linked to oxidative stress. Besides, neurotoxic effects of MIC-LR have recently been described. Herein, we evaluated the effects of environmentally important concentrations of MIC-LR (1, 10, 100, 250, and 500 μg/L) on oxidative stress markers and the survival rate of the nematode Caenorhabditis elegans (C. elegans). In addition, a possible protective effect of the carotenoid lutein (LUT) extracted from marigold flowers against MIC-LR toxicity was investigated. Higher concentrations (250 and 500 μg/L) of MIC-LR induced the generation of reactive oxygen species (ROS) and resulted in a survival loss in C elegans. Meanwhile, all MIC-LR concentrations caused an increase in the superoxide dismutase (SOD) expression, while catalase (CAT) expression was only affected at 500 μg/L. The carotenoid LUT prevented the ROS generation, impairment in the CAT expression, and the survival loss induced by MIC-LR in C. elegans. Our results confirm the toxicity of MIC-LR even in a liver-lacking invertebrate and the involvement of oxidative events in this response. Additionally, LUT appears to be able to mitigate the MIC-LR toxic effects.
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Affiliation(s)
- Paula Rossini Augusti
- Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43.212, Campus do Vale, Porto Alegre, CEP 91501-970, RS, Brazil.
| | - Allana Von Sulzback Brasil
- Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43.212, Campus do Vale, Porto Alegre, CEP 91501-970, RS, Brazil
| | - Caroline Souto
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752, Porto Alegre, CEP 90610-000, RS, Brazil
| | - Gabriela Göethel
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752, Porto Alegre, CEP 90610-000, RS, Brazil
| | - Alessandro de Oliveira Rios
- Instituto de Ciência e Tecnologia de Alimentos, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Prédio 43.212, Campus do Vale, Porto Alegre, CEP 91501-970, RS, Brazil
| | - Tatiana Emanuelli
- Núcleo Integrado de Desenvolvimento em Análises Laboratoriais (NIDAL), Departamento de Tecnologia e Ciência dos Alimentos, Centro de Ciências Rurais, Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Santa Maria, CEP 97105-900, RS, Brazil
| | - Marilise Escobar Bürger
- Laboratório de Farmacologia e Toxicologia (FARMATOX), Departamento de Fisiologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria (UFSM), Av. Roraima, 1000, Santa Maria, CEP 97105-900, RS, Brazil
| | - Solange Cristina Garcia
- Laboratório de Toxicologia (LATOX), Departamento de Análises, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Ipiranga, 2752, Porto Alegre, CEP 90610-000, RS, Brazil
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Potential Use of Chemoprotectants against the Toxic Effects of Cyanotoxins: A Review. Toxins (Basel) 2017; 9:toxins9060175. [PMID: 28545227 PMCID: PMC5488025 DOI: 10.3390/toxins9060175] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/21/2017] [Accepted: 05/17/2017] [Indexed: 12/16/2022] Open
Abstract
Cyanobacterial toxins, particularly microcystins (MCs) and cylindrospermopsin (CYN), are responsible for toxic effects in humans and wildlife. In order to counteract or prevent their toxicity, various strategies have been followed, such as the potential application of chemoprotectants. A review of the main substances evaluated for this aim, as well as the doses and their influence on cyanotoxin-induced toxicity, has been performed. A search of the literature shows that research on MCs is much more abundant than research on CYN. Among chemoprotectants, antioxidant compounds are the most extensively studied, probably because it is well known that oxidative stress is one of the toxic mechanisms common to both toxins. In this group, vitamin E seems to have the strongest protectant effect for both cyanotoxins. Transport inhibitors have also been studied in the case of MCs, as CYN cellular uptake is not yet fully elucidated. Further research is needed because systematic studies are lacking. Moreover, more realistic exposure scenarios, including cyanotoxin mixtures and the concomitant use of chemoprotectants, should be considered.
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Lone Y, Bhide M, Koiri RK. Amelioratory effect of coenzyme Q10 on potential human carcinogen Microcystin-LR induced toxicity in mice. Food Chem Toxicol 2017; 102:176-185. [PMID: 28219701 DOI: 10.1016/j.fct.2017.02.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 12/28/2016] [Accepted: 02/14/2017] [Indexed: 10/20/2022]
Abstract
Microcystins are a group of cyclic heptapeptide toxins produced by cyanobacteria. More than 100 microcystin analogues have been detected, among which microcystin-LR is the most abundant and toxic variant. Present study was designed to reveal whether potential human carcinogen microcystin-LR could imbalance the glycolytic-oxidative-nitrosative status of heart, kidney and spleen of mice and also to explore the amelioratory effect of coenzyme Q10 on microcystin-LR induced toxicity. Microcystin-LR was administered at a dose of 10 μg/kg bw/day, ip for 14 days in male mice. In microcystin-LR treated mice as compared to control, significant increase in the level of lipid peroxidation, hydrogen peroxide, lactate dehydrogenase, nitric oxide with a concomitant decrease in the level of glutathione was observed, suggesting microcystin-LR induced toxicity via induction of oxidative-nitrosative-glycolytic pathway. Although several studies have evaluated numerous antioxidants but still there is no effective chemoprotectant against microcystin-LR induced toxicity. When microcystin-LR treated mice were co-administered coenzyme Q10 (10 mg/kg bw/day, im) for 14 days, it was observed that coenzyme Q10 ameliorates microcystin-LR induced toxicity via modulation of glycolytic-oxidative-nitrosative stress pathway. Thus, the results suggest that coenzyme Q10 has a potential to be developed as preventive agent against microcystin-LR induced toxicity.
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Affiliation(s)
- Yaqoob Lone
- Department of Zoology, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India
| | - Mangla Bhide
- Department of Zoology, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India
| | - Raj Kumar Koiri
- Department of Zoology, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India.
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Clark SP, Davis MA, Ryan TP, Searfoss GH, Hooser SB. Hepatic Gene Expression Changes in Mice Associated with Prolonged Sublethal Microcystin Exposure. Toxicol Pathol 2016; 35:594-605. [PMID: 17654400 DOI: 10.1080/01926230701383210] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Microcystin-LR (MCLR) is an acute hepatotoxicant and suspected carcinogen. Previous chronic studies have individually described hepatic morphologic changes, or alterations in the cytoskeleton, cell signaling or redox pathways. The objective of this study was to characterize chronic effects of MCLR in wild-type mice utilizing gene array analysis, morphology, and plasma chemistries. MCLR was given daily for up to 28 days. RNA from the 28-day study was hybridized onto mouse genechip arrays. RNA from 4 hours, 24 hours, 4 days, 1 day, and 28 days for selected genes was processed for quantitative-PCR. Increases in plasma hepatic enzyme activities and decreases in total protein, albumin and glucose concentrations were identified in MCLR-treated groups at 14 and 28 days. Histologically, marked hepatokaryomegaly was identified in the 14-day MCLR group with the addition of giant cells at 28 days. Major gene transcript changes were identified in the actin organization, cell cycle, apoptotic, cellular redox, cell signaling, albumin metabolism, and glucose homeostasis pathways, and the organic anion transport polypeptide system. Using toxicogenomics, we have identified key molecular pathways involved in chronic sublethal MCLR exposure in wild-type mice, genes participating in those critical pathways and related them to cellular and morphologic alterations seen in this and other studies.
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Affiliation(s)
- Shawn P Clark
- Department of Veterinary Pathobiology, Purdue University, Indiana 47907, USA.
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Wu Q, Yan W, Liu C, Li L, Yu L, Zhao S, Li G. Microcystin-LR exposure induces developmental neurotoxicity in zebrafish embryo. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 213:793-800. [PMID: 27038211 DOI: 10.1016/j.envpol.2016.03.048] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/18/2016] [Accepted: 03/18/2016] [Indexed: 06/05/2023]
Abstract
Microcystin-LR (MCLR) is a commonly acting potent hepatotoxin and has been pointed out of potentially causing developmental neurotoxicity, but the exact mechanism is little known. In this study, zebrafish embryos were exposed to 0, 0.8, 1.6 or 3.2 mg/L MCLR for 120 h. MCLR exposure through submersion caused serious hatching delay and body length decrease. The content of MCLR in zebrafish larvae was analyzed and the results demonstrated that MCLR can accumulate in zebrafish larvae. The locomotor speed of zebrafish larvae was decreased. Furthermore, the dopamine and acetylcholine (ACh) content were detected to be significantly decreased in MCLR exposure groups. And the acetylcholinesterase (AChE) activity was significantly increased after exposure to 1.6 and 3.2 mg/L MCLR. The transcription pattern of manf, chrnα7 and ache gene was consistent with the change of the dopamine content, ACh content and AChE activity. Gene expression involved in the development of neurons was also measured. ɑ1-tubulin and shha gene expression were down-regulated, whereas mbp and gap43 gene expression were observed to be significantly up-regulated upon exposure to MCLR. The above results indicated that MCLR-induced developmental toxicity might attribute to the disorder of cholinergic system, dopaminergic signaling, and the development of neurons.
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Affiliation(s)
- Qin Wu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070, PR China
| | - Wei Yan
- Institute of Agricultural Quality Standards & Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064, China
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Li Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070, PR China
| | - Liqin Yu
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Sujuan Zhao
- School of Public Health, Anhui Medical University, Hefei 230032, China
| | - Guangyu Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070, PR China.
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Guzmán-Guillén R, Prieto Ortega AI, Martín-Caméan A, Cameán AM. Beneficial effects of vitamin E supplementation against the oxidative stress on Cylindrospermopsin-exposed tilapia (Oreochromis niloticus). Toxicon 2015; 104:34-42. [DOI: 10.1016/j.toxicon.2015.07.336] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/21/2015] [Accepted: 07/23/2015] [Indexed: 11/15/2022]
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18
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Mechanisms of microcystin-LR-induced cytoskeletal disruption in animal cells. Toxicon 2015; 101:92-100. [DOI: 10.1016/j.toxicon.2015.05.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 05/06/2015] [Accepted: 05/12/2015] [Indexed: 12/31/2022]
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19
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Zhang H, Fang W, Xiao W, Lu L, Jia X. Protective role of oligomeric proanthocyanidin complex against hazardous nodularin-induced oxidative toxicity in Carassius auratus lymphocytes. JOURNAL OF HAZARDOUS MATERIALS 2014; 274:247-257. [PMID: 24794815 DOI: 10.1016/j.jhazmat.2014.04.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 04/09/2014] [Accepted: 04/14/2014] [Indexed: 06/03/2023]
Abstract
Nodularin (NOD) is a hazardous material widely detected in water blooms. Fish immune cells are extremely vulnerable to NOD-induced oxidative stress. Oligomeric proanthocyanidin complex (OPC), extracted from grapeseed, was used as an antioxidant to eliminate reactive oxygen species and prevent apoptotic effects. Carassius auratus lymphocytes were treated with different concentrations (0, 10, 100, and 1,000 μg/L) of OPC and a constant dose (100 μg/L) of NOD for 12h in vitro. OPC inhibited mitosis by decreasing intracellular levels of oxidative stress, regulating antioxidant enzymes (CAT, SOD, GPx, GR, and GST), mediating bcl-2 family proteins, and deactivating caspase-3. Glutathione (GSH) levels in group V (NOD 100 μg/L; OPC 1,000 μg/L) showed a twofold increase compared with corresponding levels in group II (NOD 100 μg/L). Structure parameters of NOD and NOD-GSH were calculated using SYBYL 7.1 software. ClogP and HINK logP values of NOD-GSH decreased by 10.4- and 2.3-fold, respectively, compared with corresponding values of NOD. OPC-stimulated GSH can lower the lipophilicity and polarity of NOD. OPC, as a protective agent, can alleviate NOD-induced toxicity in C. auratus lymphocytes by regulating oxidative stress and inducing NOD-GSH detoxification.
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Affiliation(s)
- Hangjun Zhang
- Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16#, Xiasha Gaojiao Dongqu, Hangzhou 310036, Zhejiang Province, China.
| | - Wendi Fang
- Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16#, Xiasha Gaojiao Dongqu, Hangzhou 310036, Zhejiang Province, China
| | - Wenfeng Xiao
- Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16#, Xiasha Gaojiao Dongqu, Hangzhou 310036, Zhejiang Province, China
| | - Liping Lu
- Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16#, Xiasha Gaojiao Dongqu, Hangzhou 310036, Zhejiang Province, China
| | - Xiuying Jia
- Department of Environmental Sciences, Hangzhou Normal University, Xuelin Road 16#, Xiasha Gaojiao Dongqu, Hangzhou 310036, Zhejiang Province, China
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20
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Zeng C, Sun H, Xie P, Wang J, Zhang G, Chen N, Yan W, Li G. The role of apoptosis in MCLR-induced developmental toxicity in zebrafish embryos. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 149:25-32. [PMID: 24555956 DOI: 10.1016/j.aquatox.2014.01.021] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/23/2014] [Accepted: 01/27/2014] [Indexed: 06/03/2023]
Abstract
We previously demonstrated that cyanobacteria-derived microcystin-leucine-arginine (MCLR) is able to induce developing toxicity, such as malformation, growth delay and also decreased heart rates in zebrafish embryos. However, the molecular mechanisms by which MCLR induces its toxicity during the development of zebrafish remain largely unknown. Here, we evaluate the role of apoptosis in MCLR-induced developmental toxicity. Zebrafish embryos were exposed to various concentrations of MCLR (0, 0.2, 0.5, 2, and 5.0 mg L(-1)) for 96 h, at which time reactive oxygen species (ROS) was significantly induced in the 2 and 5.0 mg L(-1) MCLR exposure groups. Acridine orange (AO) staining and terminal deoxynucleotide transferase-mediated deoxy-UTP nick end labelling (TUNEL) assay showed that MCLR exposure resulted in cell apoptosis. To test the apoptotic pathway, the expression pattern of several apoptotic-related genes was examined for the level of enzyme activity, gene and protein expression, respectively. The overall results demonstrate that MCLR induced ROS which consequently triggered apoptosis in the heart of developing zebrafish embryos. Our results also indicate that the p53-Bax-Bcl-2 pathway and the caspase-dependent apoptotic pathway play major roles in MCLR-induced apoptosis in the developing embryos.
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Affiliation(s)
- Cheng Zeng
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Hong Sun
- Hubei Maternal and Child Health Hospital, Wuhan 430070, China
| | - Ping Xie
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China
| | - Jianghua Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Guirong Zhang
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Nan Chen
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Wei Yan
- Institute of Agricultural Quality Standards & Testing Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064, China.
| | - Guangyu Li
- College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070, China.
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Sebbag L, Smee N, van der Merwe D, Schmid D. Liver failure in a dog following suspected ingestion of blue-green algae (Microcystis spp.): a case report and review of the toxin. J Am Anim Hosp Assoc 2013; 49:342-6. [PMID: 23861261 DOI: 10.5326/jaaha-ms-5913] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 2.5 yr old spayed female Weimaraner presented after ingestion of blue-green algae (Microcystis spp.). One day prior to presentation, the patient was swimming at a local lake known to be contaminated with high levels of blue-green algae that was responsible for deaths of several other dogs the same summer. The patient presented 24 hr after exposure with vomiting, inappetence, weakness, and lethargy. Blood work at the time of admission was consistent with acute hepatic failure, characteristic findings of intoxication by Microcystis spp. Diagnosis was suspected by analyzing a water sample from the location where the patient was swimming. Supportive care including fluids, fresh frozen plasma, whole blood, vitamin K, B complex vitamins, S-adenosyl methionine, and Silybum marianum were started. The patient was discharged on supportive medications, and follow-up blood work showed continued improvement. Ingestion is typically fatal for most patients. This is the first canine to be reported in the literature to survive treatment after known exposure.
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Affiliation(s)
- Lionel Sebbag
- Veterinary Health Center, Kansas State University, Manhattan, KS, USA.
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Sulforaphane prevents microcystin-LR-induced oxidative damage and apoptosis in BALB/c mice. Toxicol Appl Pharmacol 2011; 255:9-17. [PMID: 21684301 DOI: 10.1016/j.taap.2011.05.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 05/11/2011] [Accepted: 05/12/2011] [Indexed: 02/07/2023]
Abstract
Microcystins (MCs), the products of blooming algae Microcystis, are waterborne environmental toxins that have been implicated in the development of liver cancer, necrosis, and even fatal intrahepatic bleeding. Alternative protective approaches in addition to complete removal of MCs in drinking water are urgently needed. In our previous work, we found that sulforaphane (SFN) protects against microcystin-LR (MC-LR)-induced cytotoxicity by activating the NF-E2-related factor 2 (Nrf2)-mediated defensive response in human hepatoma (HepG2) and NIH 3T3 cells. The purpose of this study was to investigate and confirm efficacy the SFN-induced multi-mechanistic defense system against MC-induced hepatotoxicity in an animal model. We report that SFN protected against MC-LR-induced liver damage and animal death at a nontoxic and physiologically relevant dose in BALB/c mice. The protection by SFN included activities of anti-cytochrome P450 induction, anti-oxidation, anti-inflammation, and anti-apoptosis. Our results suggest that SFN may protect mice against MC-induced hepatotoxicity. This raises the possibility of a similar protective effect in human populations, particularly in developing countries where freshwaters are polluted by blooming algae.
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Li GY, Xie P, Li HY, Hao L, Xiong Q, Qiu T. Involment of p53, Bax, and Bcl-2 pathway in microcystins-induced apoptosis in rat testis. ENVIRONMENTAL TOXICOLOGY 2011; 26:111-117. [PMID: 19760617 DOI: 10.1002/tox.20532] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
It has been reported that microcystins (MCs) could accumulate in the gonads of mammals and MCs exposure exerts obvious toxic effects on male reproductive system of mammals. We have comfirmedthat MCs could accumulate and induce apoptosis in rat testis. The p53, Bax, and Bcl-2 protein play important roles in mitochondria-dependent apoptotic pathway, and this study aimed to investigate whether the p53, Bax, and Bcl-2 pathway is involved in microcystins-induced apoptosis in rat testis and discussed the possible mechanisms. Our results show that MCs led to persistent increase of transcriptional and protein level of P53 and Bax expression but led to decrease of Bcl-2 expression, resulting in an increased ratio of Bax to Bcl-2, which might contribute to apoptotic cell death of rat testis following MCs treatment. The increased ratio of expression of Bax to that of Bcl-2 induced by MCs suggests their important role in MCs-induced apoptosis in rat testis tissue.
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Affiliation(s)
- Guang-Yu Li
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory for Freshwater Ecology and Biotechnology of China, The Chinese Academy of Sciences, Wuhan, People's Republic of China
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Gan N, Mi L, Sun X, Dai G, Chung FL, Song L. Sulforaphane protects Microcystin-LR-induced toxicity through activation of the Nrf2-mediated defensive response. Toxicol Appl Pharmacol 2010; 247:129-37. [PMID: 20600217 PMCID: PMC3577422 DOI: 10.1016/j.taap.2010.06.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 06/07/2010] [Accepted: 06/09/2010] [Indexed: 01/07/2023]
Abstract
Microcystins (MCs), a cyclic heptapeptide hepatotoxins, are mainly produced by the bloom-forming cyanobacerium Microcystis, which has become an environmental hazard worldwide. Long term consumption of MC-contaminated water may induce liver damage, liver cancer, and even human death. Therefore, in addition to removal of MCs in drinking water, novel strategies that prevent health damages are urgently needed. Sulforaphane (SFN), a natural-occurring isothiocyanate from cruciferous vegetables, has been reported to reduce and eliminate toxicities from xenobiotics and carcinogens. The purpose of the present study was to provide mechanistic insights into the SFN-induced antioxidative defense system against MC-LR-induced cytotoxicity. We performed cell viability assays, including MTS assay, colony formation assay and apoptotic cell sorting, to study MC-LR-induced cellular damage and the protective effects by SFN. The results showed that SFN protected MC-LR-induced damages at a nontoxic and physiological relevant dose in HepG2, BRL-3A and NIH 3T3 cells. The protection was Nrf2-mediated as evident by transactivation of Nrf2 and activation of its downstream genes, including NQO1 and HO-1, and elevated intracellular GSH level. Results of our studies indicate that pretreatment of cells with 10muM SFN for 12h significantly protected cells from MC-LR-induced damage. SFN-induced protective response was mediated through Nrf2 pathway.
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Affiliation(s)
- Nanqin Gan
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, CAS, People’s Republic of China
| | - Lixin Mi
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057
| | - Xiaoyun Sun
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, CAS, People’s Republic of China
| | - Guofei Dai
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, CAS, People’s Republic of China
| | - Fung-Lung Chung
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057
| | - Lirong Song
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, CAS, People’s Republic of China
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ZHANG BJ, LI XY. PROTECTIVE EFFECTS OF SELENIUM NANOPARTICLES ON OXIDATIVE STRESS AND ANTIOXIDANT ENZYMES ACTIVITIES INDUCED BY MICROCYSTINS IN THE LIVER OF MICE. ACTA ACUST UNITED AC 2010. [DOI: 10.3724/sp.j.1035.2010.00679] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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26
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Prieto AI, Jos A, Pichardo S, Moreno I, de Sotomayor MA, Moyano R, Blanco A, Cameán AM. Time-dependent protective efficacy of Trolox (vitamin E analog) against microcystin-induced toxicity in tilapia (Oreochromis niloticus). ENVIRONMENTAL TOXICOLOGY 2009; 24:563-579. [PMID: 19051281 DOI: 10.1002/tox.20458] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Microcystins (MCs), hepatotoxins from cyanobacteria, induce oxidative stress and pathological changes in fish that can be ameliorated with chemoprotectants such as vitamin E (vit E). This study investigated the time period after MCs exposure in which Trolox, a vitamin E analog, is effective against oxidative and histological damage in different organs of tilapia (Oreochromis niloticus). Fish were fed Trolox supplement (700 mg/kg diet) for 7 days, or received only commercial fish food, and then were exposed to a single oral dose of 120 microg/fish microcystin-LR, and sacrificed in 24, 48, or 72 h. The Trolox protective efficacy was evaluated based on lipid peroxidation (LPO), protein oxidation, enzymatic and non-enzymatic antioxidants, and a morphologic study. Regarding the oxidative stress biomarkers altered by MCs, the higher protective action of Trolox was observed 24 h post toxin exposure, although it extends also until 48 h in gills (superoxide dismutase (SOD), catalase (CAT)), and liver, where glutathione reductase (GR) backed to control values 48 and 72 h after the toxin application. Glutathione-S- transferase (GST) activity in the liver was ameliorated by the chemoprotectant after 24 and 48 h, although control values were not recovered. Trolox modulation of these biomarkers and its ability to quench free radicals explain the recovery of LPO values in all organs at 24 h and also in gills at 48 h. Histopathologically, Trolox efficacy was more evident after 72 h.
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Affiliation(s)
- Ana Isabel Prieto
- Area of Toxicology, Faculty of Pharmacy, University of Seville, Spain
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Oxidative stress induced by microcystin-LR on PLHC-1 fish cell line. Toxicol In Vitro 2009; 23:1445-9. [PMID: 19720136 DOI: 10.1016/j.tiv.2009.08.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 07/23/2009] [Accepted: 08/25/2009] [Indexed: 11/22/2022]
Abstract
Increasing evidences suggest that oxidative stress may play a significant role in microcystins (MCs) toxicity not only in mammals, but also in fish. In this regard, many in vivo studies have been performed but little is still known about the alteration of oxidative stress biomarkers on fish cell lines so far. In this study, the toxic effects of MC-LR were investigated in the fish cell line PLHC-1, derived from a hepatocellular carninoma of the topminnow Poeciliosis lucida, after 48 h of exposure. The different response of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST), as well as lipid peroxidation (LPO) as a biomarker of oxygen-mediated toxicity, were assessed in PLHC-1 cells. The increases in the antioxidant enzymatic activities (SOD, GPx, and GST) as well as in LPO values observed evidenced the oxidative stress induced by MC-LR exposure. Moreover, the enhancements of these enzymes could suggest an adaptative response to combat oxidative injure induced by MC-LR, confirming that this mechanism is involved in the damage induced by MCs on fish cells.
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Brzuzan P, Woźny M, Ciesielski S, Łuczyński MK, Góra M, Kuźmiński H, Dobosz S. Microcystin-LR induced apoptosis and mRNA expression of p53 and cdkn1a in liver of whitefish (Coregonus lavaretus L.). Toxicon 2009; 54:170-83. [PMID: 19374916 DOI: 10.1016/j.toxicon.2009.03.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Revised: 03/10/2009] [Accepted: 03/31/2009] [Indexed: 12/28/2022]
Abstract
There is growing evidence that adverse effects of microcystin-LR (MC-LR) are closely related to oxidative stress processes, free radicals and DNA damage, and involve major gene transcript changes. This study, utilizing gene expression analysis and plasma chemistries was the first to measure the effects of MC-LR in whitefish (Coregonus lavaretus L.), a feasible organism for pollution monitoring in aquatic systems. Fish were injected with different concentrations of MC-LR (0, 10 and 100 microg/kg of body weight) and then sacrificed at either 0, 8, 24, 48 or 72 h later, and their liver tissue were harvested for detailed investigation. Specifically, we were interested whether MC-LR is capable of: (i) modulating expression of two genes, tumor suppressor gene p53 and cdkn1a, p53 direct transcription target, and (ii) inducing apoptosis in whitefish liver. To study these effects, we developed a real-time qPCR assays useful for measuring both p53 and cdkn1a gene transcript levels in liver. To obtain necessary information for the study, either full-length p53 cDNA of whitefish (Wf-p53) was determined, using molecular cloning and rapid amplification of cDNA ends (RACE), or as for Wf-cdkn1a, specific primers were designed based on highly conserved regions of cdkn1a in fish. The Wf-p53 was found to share the same characteristics with a known p53 mRNA sequence of other vertebrates. Whitefish p53 amino acid sequence showed a high degree of homology with the sequences from fishes, amphibians, and mammals. The injection study showed that MC-LR at a higher dose, i.e. 100 microg/kg body weight, up-regulated expression of p53 and cdkn1a genes in whitefish liver, as reflected by the continuous increase in their mRNA levels through the whole experiment. Furthermore, DNA fragmentation was observed in liver cells of whitefish after 24h of exposure to MC-LR (100 microg/kg) that suggests the possibility of apoptosis. Finally, the study confirmed previous observations of severe injury of the liver and loss of normal organ functions as revealed by elevated levels of blood AspAT, AlaAT, and hepatosomatic index (HSI).
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Affiliation(s)
- Paweł Brzuzan
- Department of Environmental Biotechnology, University of Warmia and Mazury, Słoneczna 45G, 10-718 Olsztyn, Poland.
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Effects of dietary selenium on the oxidative stress and pathological changes in tilapia (Oreochromis niloticus) exposed to a microcystin-producing cyanobacterial water bloom. Toxicon 2009; 53:269-82. [DOI: 10.1016/j.toxicon.2008.11.011] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 11/25/2008] [Accepted: 11/26/2008] [Indexed: 11/24/2022]
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Ruebhart DR, Wickramasinghe W, Cock IE. Protective efficacy of the antioxidants vitamin E and Trolox against Microcystis aeruginosa and microcystin-LR in Artemia franciscana nauplii. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2009; 72:1567-1575. [PMID: 20077231 DOI: 10.1080/15287390903232459] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This study was undertaken to evaluate the protective efficacy of the antioxidants vitamin E and Trolox (a water-soluble vitamin E derivative) against the toxicity of microcystin-LR (MC-LR), Microcystis aeruginosa aqueous extract (CE), and a reference toxin, menadione sodium bisulfite (MSB), in Artemia franciscana nauplii. This was achieved by using the well-established brine shrimp bioassay. The experiment was conducted in 2 stages, with (1) 12-h mortality time course and (2) LC50 determination for 12- and 24-h exposures. Treatments consisted of MC-LR, CE, and MSB alone and with 4-h pretreatments of either vitamin E or Trolox. Sensitivity of A. franciscana nauplii with 24-h LC50 values of 11 (10.1-12.1) microg/ml for MSB and 9.5 (8.8-10.4) microg/ml for MC-LR were in general agreement with values reported for Artemia sp. Both antioxidant pretreatments resulted in significant reductions in mortality of approximately 50% at 9 h postexposure when challenged by either 40 microg/ml MC-LR or 20 microg/ml MSB. In contrast, the antioxidant pretreatments offered little to no protection from CE, suggesting that other uncharacterized bioactive compounds contributed to overall toxicity. The described bioassay is easily accessible, inexpensive, rapid, and complies with animal ethics guidelines of many countries, and thus provides a potential alternative to the mouse bioassay for the initial screening for chemoprotectants against MC-LR toxicity.
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31
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Zhao Y, Xie P, Tang R, Zhang X, Li L, Li D. In vivo studies on the toxic effects of microcystins on mitochondrial electron transport chain and ion regulation in liver and heart of rabbit. Comp Biochem Physiol C Toxicol Pharmacol 2008; 148:204-10. [PMID: 18590982 DOI: 10.1016/j.cbpc.2008.05.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2008] [Revised: 05/19/2008] [Accepted: 05/20/2008] [Indexed: 11/24/2022]
Abstract
This study examined the toxic effects of microcystins on mitochondria of liver and heart of rabbit in vivo. Rabbits were injected i.p. with extracted microcystins (mainly MC-RR and -LR) at two doses, 12.5 and 50 MC-LReq. microg/kg bw, and the changes in mitochondria of liver and heart were studied at 1, 3, 12, 24 and 48 h after injection. MCs induced damage of mitochondrial morphology and lipid peroxidation in both liver and heart. MCs influenced respiratory activity through inhibiting NADH dehydrogenase and enhancing succinate dehydrogenase (SDH). MCs altered Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities of mitochondria and consequently disrupted ionic homeostasis, which might be partly responsible for the loss of mitochondrial membrane potential (MMP). MCs were highly toxic to mitochondria with more serious damage in liver than in heart. Damage of mitochondria showed reduction at 48 h in the low dose group, suggesting that the low dose of MCs might have stimulated a compensatory response in the rabbits.
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Affiliation(s)
- Yanyan Zhao
- Fisheries College of Huazhong Agricultural University; Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Wuhan 430070, People's Republic of China
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Hudder A, Song W, O'Shea KE, Walsh PJ. Toxicogenomic evaluation of microcystin-LR treated with ultrasonic irradiation. Toxicol Appl Pharmacol 2007; 220:357-64. [PMID: 17383702 PMCID: PMC1971717 DOI: 10.1016/j.taap.2007.02.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2006] [Revised: 02/08/2007] [Accepted: 02/11/2007] [Indexed: 11/29/2022]
Abstract
Microcystins are a family of toxins produced by cyanobacteria found throughout the world in marine and freshwater environments. The most commonly encountered form of microcystin is microcystin-LR (MC-LR). Humans are exposed to MC-LR by drinking contaminated water. The toxin accumulates rapidly in the liver where it exerts most of its damage. Treatment of water containing MC-LR by ultrasonic irradiation leads to the breakdown of the toxin. Both the parent toxin and the treated toxin reaction products (TTRP) were evaluated for toxic effects in mice. Animals were exposed to purified MC-LR or an equivalent dose of the TTRP and sacrificed after 4 h or 24 h. Serum was collected and assayed for lactate dehydrogenase (LDH) activity as an indicator of hepatotoxicity. LDH activity was detected in the serum of MC-LR exposed mice indicative of liver damage, but not in control mice. Only a fraction of that activity was detectable in mice exposed to TTRP. Liver RNA was used for microarray analysis and real-time PCR. Individual animals varied in their overall genomic response to the toxin; however, only 20 genes showed consistent changes in expression. These include chaperones which may be part of a generalized stress response; cytochrome P450 which may be involved in metabolizing the toxin; and lipid dystrophy genes such as lipin-2, uridine phosphorylase and a homolog to tribbles, a stress-inducible gene involved in cell death. Of the genes that responded to the MC-LR, none showed significant changes in expression profile in response to TTRP. Taken together, the data indicate that ultrasonic irradiation of MC-LR effectively reduces hepatotoxicity in mice and therefore may be a useful method for detoxification of drinking water.
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Affiliation(s)
- Alice Hudder
- Division of Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Virginia Key, FL 33149, USA
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Weng D, Lu Y, Wei Y, Liu Y, Shen P. The role of ROS in microcystin-LR-induced hepatocyte apoptosis and liver injury in mice. Toxicology 2006; 232:15-23. [PMID: 17223243 DOI: 10.1016/j.tox.2006.12.010] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2006] [Revised: 12/04/2006] [Accepted: 12/05/2006] [Indexed: 11/16/2022]
Abstract
Microcystin-LR (MC-LR) produced by cyanobacteria in diverse water systems is a potent specific hepatotoxin and has been documented to induce hepatocyte apoptosis and liver injury; however, the mechanisms have not been fully elucidated. In the present study, we investigated whether MC-LR stimulated ROS generation in the liver of mice and the role of ROS in the pathogenesis of MC-LR-induced liver injury in vivo. MC-LR treatment (60 microg/kg of body weight) for 12h prompted large amount of ROS generation in mice liver, upregulated the expression of Bax and Bid, caused the mitochondrial membrane potential (MMP) loss and hepatocyte apoptosis as well as liver injury. While pretreatment with antioxidants, oral administration of vitamin C (250mg/kg of body weight, dissolved in double distill water) and vitamin E (200mg/kg of body weight, dissolved in corn oil) per day for 3 days continually, significantly reduced the generation of ROS and effectively inhibited the MC-LR-induced hepatocyte apoptosis and liver injury, suggesting that ROS played a critical role in MC-LR-induced hepatocyte apoptosis and liver injury. The protective effect of vitamin C and E also suggested the potential interest in the clinical treatment of MC-LR-induced liver injury and hepatotoxicity.
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Affiliation(s)
- Dan Weng
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China
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Sicińska P, Bukowska B, Michałowicz J, Duda W. Damage of cell membrane and antioxidative system in human erythrocytes incubated with microcystin-LR in vitro. Toxicon 2006; 47:387-97. [PMID: 16457864 DOI: 10.1016/j.toxicon.2005.12.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2005] [Revised: 11/28/2005] [Accepted: 12/06/2005] [Indexed: 11/28/2022]
Abstract
The effect of the exposure of human erythrocytes to different concentrations of microcystin-LR were studied. Lipid peroxidation, membrane fluidity, cell morphology, haemoglobin oxidation and changes in the activity of antioxidant enzymes were investigated. Human erythrocytes were incubated with microcystin-LR at concentrations of 1-1000 nM for 1, 6, 12 and 24 h. We observed that microcystin-LR induces a significant increase of the level of thiobarbituric acid reactive substances (TBARS), formation of echinocytes, haemolysis, conversion of oxyhaemoglobin to methaemoglobin, decrease of membrane fluidity on the level of 16 carbon atom fat acids. The compound also changed antioxidative enzymes activities: catalase, superoxide dismutase and glutathione reductase and formation of reactive oxygen species (ROS). All of the observed changes point out that 100 nM of Microcistin LR is the liminal (threshold) toxic dose for human erythrocytes. This dose caused most of the described changes. Observed damages of erythrocytes membrane and antioxidative enzymes may be the result of direct covalent binding of microcystin-LR with -SH residues of proteins and indirectly be related with reactive oxygen species formation.
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Affiliation(s)
- Paulina Sicińska
- Department of Biophysics Environmental Pollution, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland
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Dittmann E, Wiegand C. Cyanobacterial toxins - occurrence, biosynthesis and impact on human affairs. Mol Nutr Food Res 2006; 50:7-17. [PMID: 16304634 DOI: 10.1002/mnfr.200500162] [Citation(s) in RCA: 283] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mass developments of cyanobacteria ("blue-green algae") in lakes and brackish waters have repeatedly led to serious concerns due to their frequent association with toxins. Among these are the widespread hepatotoxins microcystin (MC) and nodularin (NOD). Here, we give an overview about the ecostrategies of the diverse toxin-producing species and about the genes and enzymes that are involved in the biosynthesis of the cyclic peptides. We further summarize current knowledge about toxicological mechanisms of MC and NOD, including protein phosphatase inhibition, oxidative stress and their tumor-promoting capabilities. One biotransformation pathway for MC is described. Mechanisms of cyanobacterial neurotoxins (anatoxin-a, homanatoxin-a, and anatoxin-a(s)) are briefly explained. We highlight selected cases of human fatalities related to the toxins. A special focus is given to evident cases of contamination of food supplements with cyanobacterial toxins, and to the necessary precautions.
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Affiliation(s)
- Elke Dittmann
- Humboldt University, Institute of Biology, Berlin, Germany.
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36
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Pinho GLL, da Rosa CM, Maciel FE, Bianchini A, Yunes JS, Proença LAO, Monserrat JM. Antioxidant responses after microcystin exposure in gills of an estuarine crab species pre-treated with vitamin E. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2005; 61:361-5. [PMID: 15922802 DOI: 10.1016/j.ecoenv.2004.12.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Accepted: 12/02/2004] [Indexed: 05/02/2023]
Abstract
Microcystins are hepatotoxins suspected to generate oxidative stress. This mechanism was evaluated in gills of the estuarine crab Chasmagnathus granulatus (Decapoda, Brachyura). Adult male crabs were fed ground beef with or without vitamin E (600 mg/kg). Microcystin (1.21 microg/kg) was daily administered through forced ingestion, for 7 days. After exposure, catalase activity was reduced in posterior gills of crabs supplemented with vitamin E. A lower increment in glutathione S-transferase activity (GST) was observed in organisms pretreated with vitamin E and then exposed to microcystin with respect to those exposed to the toxin but not pretreated with the vitamin. Pretreatment with vitamin E also increased nonproteic sulfhyrdil groups and this effect was not observed after microcystin exposure. The fact that supplementation with antioxidants such as vitamin E modulates GST activity indicates the direct or indirect involvement of microcystin in oxidative stress generation.
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Affiliation(s)
- G L L Pinho
- Departamento de Ciências Fisiológicas, Fundação Universidade Federal do Rio Grande, 96201-900 Rio Grande, RS, Brazil
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Chen T, Wang Q, Cui J, Yang W, Shi Q, Hua Z, Ji J, Shen P. Induction of Apoptosis in Mouse Liver by Microcystin-LR. Mol Cell Proteomics 2005; 4:958-74. [PMID: 15863401 DOI: 10.1074/mcp.m400185-mcp200] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Microcystins (MCs) are a family of cyclic heptapeptide hepatotoxins produced by freshwater species of cyanobacteria that have been implicated in the development of liver cancer, necrosis, and even deadly intrahepatic bleeding. MC-LR, the most toxic MC variant, is also the most commonly encountered in a contaminated aquatic system. This study presents the first data in the toxicological research of MCs that combines the use of standard apoptotic assays with transcriptomics, proteomic technologies, and computer simulations. By using histochemistry, DNA fragmentation assays, and flow cytometry analysis, we determined that MC-LR causes rapid, dose-dependent apoptosis in mouse liver when BALB/c mice are treated with MC-LR for 24 h at doses of either 50, 60, or 70 microg/kg of body weight. We then used gene expression profiling to demonstrate differential expressions (>2-fold) of 61 apoptosis-related genes in cells treated with MC-LR. Further proteomic analysis identified a total of 383 proteins of which 35 proteins were up-regulated and 30 proteins were down-regulated more than 2.5-fold when compared with controls. Combining computer simulations with the transcriptomic and proteomic data, we found that low doses (50 microg/kg) of MC-LR lead to apoptosis primarily through the BID-BAX-BCL-2 pathway, whereas high doses of MC-LR (70 microg/kg) caused apoptosis via a reactive oxygen species pathway. These results indicated that MC-LR exposure can cause apoptosis in mouse liver and revealed two independent pathways playing a major regulatory role in MC-LR-induced apoptosis, thereby contributing to a better understanding of the hepatotoxicity and the tumor-promoting mechanisms of MCs.
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Affiliation(s)
- Ting Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, Nanjing University, Nanjing 210093, China
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38
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Wiegand C, Pflugmacher S. Ecotoxicological effects of selected cyanobacterial secondary metabolites: a short review. Toxicol Appl Pharmacol 2005; 203:201-18. [PMID: 15737675 DOI: 10.1016/j.taap.2004.11.002] [Citation(s) in RCA: 337] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2004] [Accepted: 11/02/2004] [Indexed: 11/27/2022]
Abstract
Cyanobacteria are one of the most diverse groups of gram-negative photosynthetic prokaryotes. Many of them are able to produce a wide range of toxic secondary metabolites. These cyanobacterial toxins can be classified in five different groups: hepatotoxins, neurotoxins, cytotoxins, dermatotoxins, and irritant toxins (lipopolysaccharides). Cyanobacterial blooms are hazardous due to this production of secondary metabolites and endotoxins, which could be toxic to animals and plants. Many of the freshwater cyanobacterial blooms include species of the toxigenic genera Microcystis, Anabaena, or Plankthotrix. These compounds differ in mechanisms of uptake, affected organs, and molecular mode of action. In this review, the main focus is the aquatic environment and the effects of these toxins to the organisms living there. Some basic toxic mechanisms will be discussed in comparison to the mammalian system.
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Affiliation(s)
- C Wiegand
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany.
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39
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de Figueiredo DR, Azeiteiro UM, Esteves SM, Gonçalves FJM, Pereira MJ. Microcystin-producing blooms--a serious global public health issue. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2004; 59:151-63. [PMID: 15327870 DOI: 10.1016/j.ecoenv.2004.04.006] [Citation(s) in RCA: 309] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2003] [Revised: 04/14/2004] [Accepted: 04/20/2004] [Indexed: 05/22/2023]
Abstract
The investigation on microcystin topics is increasing due to the related ecological and public health risks. Recent investigation confirms a gap in establishing global patterns relating a particular environment to the bloom occurrence of a species and the production of certain microcystin variants. All the results concerning the environmental effects on the microcystin synthesis of one species must be checked in the light of genome diversity. Thus, the poisoning risks of a bloom depend on the strain causing toxicity. To be more effective, specific water treatment methods are required for blooms of different microcystin producing species (such as colonial and filamentous cyanobacteria found in stratified and unstratified water bodies, respectively). With the increasing number of new microcystin variants discovered, the development of new rapid, inexpensive and sensitive enough monitoring methods to promptly screen simultaneously a great diversity of toxins and also check their toxic effects is becoming necessary.
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40
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Gehringer MM, Shephard EG, Downing TG, Wiegand C, Neilan BA. An investigation into the detoxification of microcystin-LR by the glutathione pathway in Balb/c mice. Int J Biochem Cell Biol 2004; 36:931-41. [PMID: 15006645 DOI: 10.1016/j.biocel.2003.10.012] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2003] [Revised: 09/30/2003] [Accepted: 10/13/2003] [Indexed: 11/23/2022]
Abstract
Toxin-producing cyanobacteria pose a world-wide health threat to humans and animals due to their increasing presence in both drinking and recreational waters. The predominant cyanotoxin, microcystin-LR (MCLR), targets the liver and its toxicity depends on the uptake and removal rates in the liver. The role of the glutathione detoxification pathway in protecting the liver from the effects of MCLR was investigated. Mice exposed to a single 75% LD(50) dose of pure MCLR were sacrificed at 8, 16, 24 and 32 h post-exposure (pe). Toxin induced liver damage was observed 8 and 16 h pe as evidenced by raised serum ALT and LDH levels, reduced glycogen levels and liver histology. A significant increase in lipid peroxidation was seen at 16 h pe that decreased after 24 and 32 h pe, the time-points which showed significant increases in GPX activity. An increase in soluble GST activity was noted between 8 and 16 h pe, levels of total GSH increased at 24 h while oxidised glutathione increased throughout the investigation. The increase in activity of both GPX and GST corresponded with increased transcription of these enzymes, as well as the rate-limiting enzyme in GSH synthesis, gamma-glutamyl transferase. In conclusion, this study confirms that an increase in GST activity is critical for the detoxification of MCLR, that this is regulated at the transcriptional level, and that exposure to MCLR induces the de novo synthesis of GSH. Finally, we report the involvement of GPX in the removal of MCLR-induced lipid hydroperoxides.
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Affiliation(s)
- Michelle M Gehringer
- MRC/UCT Liver Research Centre, Groote Schuur Hospital, University of Cape Town, Old Main Building, Rondebosch, Cape Town, South Africa.
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