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Arsenic Toxicity: Molecular Targets and Therapeutic Agents. Biomolecules 2020; 10:biom10020235. [PMID: 32033229 PMCID: PMC7072575 DOI: 10.3390/biom10020235] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/30/2020] [Accepted: 01/30/2020] [Indexed: 12/13/2022] Open
Abstract
High arsenic (As) levels in food and drinking water, or under some occupational conditions, can precipitate chronic toxicity and in some cases cancer. Millions of people are exposed to unacceptable amounts of As through drinking water and food. Highly exposed individuals may develop acute, subacute, or chronic signs of poisoning, characterized by skin lesions, cardiovascular symptoms, and in some cases, multi-organ failure. Inorganic arsenite(III) and organic arsenicals with the general formula R-As2+ are bound tightly to thiol groups, particularly to vicinal dithiols such as dihydrolipoic acid (DHLA), which together with some seleno-enzymes constitute vulnerable targets for the toxic action of As. In addition, R-As2+-compounds have even higher affinity to selenol groups, e.g., in thioredoxin reductase that also possesses a thiol group vicinal to the selenol. Inhibition of this and other ROS scavenging seleno-enzymes explain the oxidative stress associated with arsenic poisoning. The development of chelating agents, such as the dithiols BAL (dimercaptopropanol), DMPS (dimercapto-propanesulfonate) and DMSA (dimercaptosuccinic acid), took advantage of the fact that As had high affinity towards vicinal dithiols. Primary prevention by reducing exposure of the millions of people exposed to unacceptable As levels should be the prioritized strategy. However, in acute and subacute and even some cases with chronic As poisonings chelation treatment with therapeutic dithiols, in particular DMPS appears promising as regards alleviation of symptoms. In acute cases, initial treatment with BAL combined with DMPS should be considered.
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Bjørklund G, Crisponi G, Nurchi VM, Cappai R, Buha Djordjevic A, Aaseth J. A Review on Coordination Properties of Thiol-Containing Chelating Agents Towards Mercury, Cadmium, and Lead. Molecules 2019; 24:E3247. [PMID: 31489907 PMCID: PMC6767255 DOI: 10.3390/molecules24183247] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 08/26/2019] [Accepted: 08/31/2019] [Indexed: 11/17/2022] Open
Abstract
The present article reviews the clinical use of thiol-based metal chelators in intoxications and overexposure with mercury (Hg), cadmium (Cd), and lead (Pb). Currently, very few commercially available pharmaceuticals can successfully reduce or prevent the toxicity of these metals. The metal chelator meso-2,3-dimercaptosuccinic acid (DMSA) is considerably less toxic than the classical agent British anti-Lewisite (BAL, 2,3-dimercaptopropanol) and is the recommended agent in poisonings with Pb and organic Hg. Its toxicity is also lower than that of DMPS (dimercaptopropane sulfonate), although DMPS is the recommended agent in acute poisonings with Hg salts. It is suggested that intracellular Cd deposits and cerebral deposits of inorganic Hg, to some extent, can be mobilized by a combination of antidotes, but clinical experience with such combinations are lacking. Alpha-lipoic acid (α-LA) has been suggested for toxic metal detoxification but is not considered a drug of choice in clinical practice. The molecular mechanisms and chemical equilibria of complex formation of the chelators with the metal ions Hg2+, Cd2+, and Pb2+ are reviewed since insight into these reactions can provide a basis for further development of therapeutics.
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Affiliation(s)
- Geir Bjørklund
- Council for Nutritional and Environmental Medicine, N-8610 Mo i Rana, Norway.
| | - Guido Crisponi
- Cittadella Universitaria, University of Cagliari, 09042 Cagliari, Italy.
| | - Valeria Marina Nurchi
- Department of Life and Environmental Sciences, University of Cagliari, 09042 Cagliari, Italy.
| | - Rosita Cappai
- Department of Life and Environmental Sciences, University of Cagliari, 09042 Cagliari, Italy.
| | - Aleksandra Buha Djordjevic
- Department of Toxicology "Akademik Danilo Soldatović", Faculty of Pharmacy, University of Belgrade, 11000 Belgrade, Serbia.
| | - Jan Aaseth
- Research Department, Innlandet Hospital, N-2380 Brumunddal, Norway.
- Inland Norway University of Applied Sciences, N-2411 Elverum, Norway.
- IM Sechenov First Moscow State Medical University (Sechenov University), 119146 Moscow, Russia.
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Bjørklund G, Mutter J, Aaseth J. Metal chelators and neurotoxicity: lead, mercury, and arsenic. Arch Toxicol 2017; 91:3787-3797. [DOI: 10.1007/s00204-017-2100-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 10/19/2017] [Indexed: 01/07/2023]
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Andersen O, Aaseth J. A review of pitfalls and progress in chelation treatment of metal poisonings. J Trace Elem Med Biol 2016; 38:74-80. [PMID: 27150911 DOI: 10.1016/j.jtemb.2016.03.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 03/14/2016] [Accepted: 03/17/2016] [Indexed: 01/31/2023]
Abstract
Most acute and chronic human metal poisonings are due to oral or inhalation exposure. Almost 80% of published animal experiments on chelation in metal poisoning used single or repeated intraperitoneal, intramuscular or intravenous administration of metal and chelator, impeding extrapolation to clinical settings. Intramuscular administration of dimercaptopropanol (BAL) has until now been used in acute arsenic, lead, and mercury poisonings, but repeated BAL administration increased the brain uptake of As, Pb and Hg in experimental animals. Also, diethyl dithiocarbamate (DDC) has been used as antidote in acute experimental animal parenteral Cd poisoning, and both DDC and tetraethylthiuram disulfide (TTD, disulfiram, Antabuse) have been used in nickel allergic patients. However, even one dose of DDC given immediately after oral Cd or Ni increased their brain uptake considerably. The calcium salt of ethylenediamminetetraacetic acid (CaEDTA) but not dimercaptosuccinic acid (DMSA) increased the brain uptake of Pb. In oral Cd or Hg poisoning, early oral administration of DMSA or dimercaptopropane sulfonate (DMPS) increased survival and reduced intestinal metal uptake. Oral administration of Prussian Blue or resins with fixed chelating groups that are not absorbed offer chelation approaches for decorporation after oral exposure to various metals. Diethylenetriaminepentaacetic acid (DTPA) nebulizers for pulmonary chelation after inhalation exposure need further development. Also, combined chelation with more than one compound may offer extensive advances. Solid knowledge on the chemistry of metal chelates together with relevant animal experiments should guide development of chelation procedures to alleviate and not aggravate the clinical status of poisoned patients.
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Affiliation(s)
- Ole Andersen
- Roskilde University, Roskilde, Denmark, Denmark.
| | - Jan Aaseth
- Innlandet Hospital Trust and Hedmark University College, Elverum, Norway, Norway
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Remelli M, Nurchi VM, Lachowicz JI, Medici S, Zoroddu MA, Peana M. Competition between Cd(II) and other divalent transition metal ions during complex formation with amino acids, peptides, and chelating agents. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.07.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Dathe K, Beck E, Schaefer C. Pregnancy outcome after chelation therapy in Wilson disease. Evaluation of the German Embryotox Database. Reprod Toxicol 2016; 65:39-45. [DOI: 10.1016/j.reprotox.2016.06.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/06/2016] [Accepted: 06/22/2016] [Indexed: 02/04/2023]
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Cao Y, Skaug MA, Andersen O, Aaseth J. Chelation therapy in intoxications with mercury, lead and copper. J Trace Elem Med Biol 2015; 31:188-92. [PMID: 24894443 DOI: 10.1016/j.jtemb.2014.04.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/22/2014] [Accepted: 04/23/2014] [Indexed: 11/15/2022]
Abstract
In the present review we provide an update of the appropriate use of chelating agents in the treatment of intoxications with compounds of mercury, lead and copper. The relatively new chelators meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-propanesulphonate (DMPS) can effectively mobilize deposits of mercury as well as of lead into the urine. These drugs can be administered orally and have relatively low toxicity compared to the classical antidote dimercaptopropanol (BAL). d-Penicillamine has been widely used in copper overload, although 2,3-dimercaptosuccinic acid or tetrathiomolybdate may be more suitable alternatives today. In copper-toxicity, a free radical scavenger might be recommended as adjuvant to the chelator therapy.
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Affiliation(s)
- Yang Cao
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Marit Aralt Skaug
- Faculty of Public Health, Hedmark University College, Elverum, Norway.
| | - Ole Andersen
- Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark
| | - Jan Aaseth
- Innlandet Hospital Trust, Kongsvinger Hospital Division, Kongsvinger, Norway
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Aaseth J, Skaug MA, Cao Y, Andersen O. Chelation in metal intoxication--Principles and paradigms. J Trace Elem Med Biol 2015; 31:260-6. [PMID: 25457281 DOI: 10.1016/j.jtemb.2014.10.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 08/14/2014] [Accepted: 10/06/2014] [Indexed: 01/19/2023]
Abstract
The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due to the inconvenience of parenteral administration, their own toxicity and tendency to increase the neurotoxicity of several metals. The hydrophilic dithiol chelators DMSA (meso-2,3-dimercaptosuccinic acid) and DMPS (2,3-dimercapto-propanesulphonate) are less toxic and more efficient than BAL in the clinical treatment of heavy metal poisoning, and available as capsules for oral use. In copper overload, DMSA appears to be a potent antidote, although d-penicillamine is still widely used. In the chelation of iron, the thiols are inefficient, since iron has higher affinity for ligands with nitrogen and oxygen, but the new oral iron antidotes deferiprone and desferasirox have entered into the clinical arena. Comparisons of these agents and deferoxamine infusions are in progress. General principles for research and development of new chelators are briefly outlined in this review.
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Affiliation(s)
- Jan Aaseth
- Innlandet Hospital Trust, Kongsvinger Hospital Division, Kongsvinger, Norway
| | - Marit Aralt Skaug
- Faculty of Public Health, Hedmark University College, 2418 Elverum, Norway.
| | - Yang Cao
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Ole Andersen
- Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark
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Biochemical and Immunotoxicological Evaluation of Metal Chelating Drugs in Rats. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/bf03259591] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Macías Konstantopoulos W, Burns Ewald M, Pratt DS. Case records of the Massachusetts General Hospital. Case 22-2012. A 34-year-old man with intractable vomiting after ingestion of an unknown substance. N Engl J Med 2012; 367:259-68. [PMID: 22808962 DOI: 10.1056/nejmcpc1111580] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Flora SJS. Arsenic-induced oxidative stress and its reversibility. Free Radic Biol Med 2011; 51:257-81. [PMID: 21554949 DOI: 10.1016/j.freeradbiomed.2011.04.008] [Citation(s) in RCA: 536] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2010] [Revised: 03/18/2011] [Accepted: 04/04/2011] [Indexed: 12/12/2022]
Abstract
This review summarizes the literature describing the molecular mechanisms of arsenic-induced oxidative stress, its relevant biomarkers, and its relation to various diseases, including preventive and therapeutic strategies. Arsenic alters multiple cellular pathways including expression of growth factors, suppression of cell cycle checkpoint proteins, promotion of and resistance to apoptosis, inhibition of DNA repair, alterations in DNA methylation, decreased immunosurveillance, and increased oxidative stress, by disturbing the pro/antioxidant balance. These alterations play prominent roles in disease manifestation, such as carcinogenicity, genotoxicity, diabetes, cardiovascular and nervous systems disorders. The exact molecular and cellular mechanisms involved in arsenic toxicity are rather unrevealed. Arsenic alters cellular glutathione levels either by utilizing this electron donor for the conversion of pentavalent to trivalent arsenicals or directly binding with it or by oxidizing glutathione via arsenic-induced free radical generation. Arsenic forms oxygen-based radicals (OH(•), O(2)(•-)) under physiological conditions by directly binding with critical thiols. As a carcinogen, it acts through epigenetic mechanisms rather than as a classical mutagen. The carcinogenic potential of arsenic may be attributed to activation of redox-sensitive transcription factors and other signaling pathways involving nuclear factor κB, activator protein-1, and p53. Modulation of cellular thiols for protection against reactive oxygen species has been used as a therapeutic strategy against arsenic. N-acetylcysteine, α-lipoic acid, vitamin E, quercetin, and a few herbal extracts show prophylactic activity against the majority of arsenic-mediated injuries in both in vitro and in vivo models. This review also updates the reader on recent advances in chelation therapy and newer therapeutic strategies suggested to treat arsenic-induced oxidative damage.
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Affiliation(s)
- Swaran J S Flora
- Division of Pharmacology & Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.
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Al Abdel Hamid A, Tripp CP, Bruce AE, Bruce MR. Preferential adsorption of mercury(II) ions in water: chelation of mercury, cadmium, and lead ions to silica derivatized with meso-2,3-dimercaptosuccinic acid. J COORD CHEM 2010. [DOI: 10.1080/00958971003663493] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Amer Al Abdel Hamid
- a Department of Chemistry , University of Maine , Orono, ME 04469, USA
- b Laboratory for Surface Science and Technology (LASST) , University of Maine , Orono, ME 04469, USA
| | - Carl P. Tripp
- a Department of Chemistry , University of Maine , Orono, ME 04469, USA
- b Laboratory for Surface Science and Technology (LASST) , University of Maine , Orono, ME 04469, USA
| | - Alice E. Bruce
- a Department of Chemistry , University of Maine , Orono, ME 04469, USA
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Sharma A, Sharma V, Kansal L. Amelioration of lead-induced hepatotoxicity by Allium sativum extracts in Swiss albino mice. Libyan J Med 2010; 5:4621. [PMID: 28156294 PMCID: PMC3066784 DOI: 10.3402/ljm.v5i0.4621] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Lead is a blue-gray and highly toxic divalent metal that occurs naturally in the earth's crust and is spread throughout the environment by various human activities. The efficacy of garlic (Allium sativum) to reduce hepatotoxicity induced by lead nitrate was evaluated experimentally in male mice. Oral treatment with lead nitrate at a dose of 50 mg/kg body weight daily for 40 days (1/45 of LD50) induced a significant increase in the levels of hepatic aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, acid phosphatase, cholesterol, lipid peroxidation, and lead nitrate. In parallel, hepatic protein levels in lead-exposed mice were significantly depleted. Lead nitrate exposure also produced detrimental effects on the redox status of the liver indicated by a significant decline in the levels of liver antioxidants such as superoxide dismutase, catalase, and glutathione. After exposure to lead nitrate (50 mg/kg body weight for 10 days), the animals received aqueous garlic extract (250 mg/kg body weight and 500 mg/kg body weight) and ethanolic garlic extract (100 mg/kg body weight and 250 mg/kg body weight), and partially restored the deranged parameters significantly. Histological examination of the liver also revealed pathophysiological changes in lead nitrate-exposed group and treatment with garlic improved liver histology. Our data suggest that garlic is a phytoantioxidant that can counteract the deleterious effects of lead nitrate.
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Affiliation(s)
- Arti Sharma
- Arti Sharma, Department of Bioscience and Biotechnology, Banasthali University, Banasthali, Rajasthan, India.
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Sharma A, Sharma V, Kansal L. Amelioration of lead-induced hepatotoxicity by Allium sativum extracts in Swiss albino mice. Libyan J Med 2010; 5:10.4176/091107. [PMID: 21483544 PMCID: PMC3066784 DOI: 10.4176/091107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 09/30/2009] [Indexed: 01/28/2023] Open
Abstract
Lead is a blue-gray and highly toxic divalent metal that occurs naturally in the earth's crust and is spread throughout the environment by various human activities. The efficacy of garlic (Allium sativum) to reduce hepatotoxicity induced by lead nitrate was evaluated experimentally in male mice. Oral treatment with lead nitrate at a dose of 50 mg/kg body weight daily for 40 days (1/45 of LD(50)) induced a significant increase in the levels of hepatic aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, acid phosphatase, cholesterol, lipid peroxidation, and lead nitrate. In parallel, hepatic protein levels in lead-exposed mice were significantly depleted. Lead nitrate exposure also produced detrimental effects on the redox status of the liver indicated by a significant decline in the levels of liver antioxidants such as superoxide dismutase, catalase, and glutathione. After exposure to lead nitrate (50 mg/kg body weight for 10 days), the animals received aqueous garlic extract (250 mg/kg body weight and 500 mg/kg body weight) and ethanolic garlic extract (100 mg/kg body weight and 250 mg/kg body weight), and partially restored the deranged parameters significantly. Histological examination of the liver also revealed pathophysiological changes in lead nitrate-exposed group and treatment with garlic improved liver histology. Our data suggest that garlic is a phytoantioxidant that can counteract the deleterious effects of lead nitrate.
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Affiliation(s)
- Arti Sharma
- Arti Sharma, Department of Bioscience and Biotechnology, Banasthali University, Banasthali, Rajasthan, India.
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Scott LE, Orvig C. Medicinal Inorganic Chemistry Approaches to Passivation and Removal of Aberrant Metal Ions in Disease. Chem Rev 2009; 109:4885-910. [DOI: 10.1021/cr9000176] [Citation(s) in RCA: 266] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Lauren E. Scott
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, Vancouver, Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, Vancouver, Canada
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Mishra D, Flora SJS. Quercetin administration during chelation therapy protects arsenic-induced oxidative stress in mice. Biol Trace Elem Res 2008; 122:137-47. [PMID: 18183357 DOI: 10.1007/s12011-007-8064-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 10/25/2007] [Accepted: 11/27/2007] [Indexed: 01/12/2023]
Abstract
We studied the efficacy of quercetin and a thiol chelating agent, monoisoamyl 2, 3-dimercaptosuccinic acid (MiADMSA) either individually or in combination against arsenic-induced oxidative stress and mobilization of metal in mouse. Animals were chronically exposed to 25 ppm arsenite as sodium arsenite in drinking water for 12 months followed by treatment with MiADMSA (0.2 mmol/kg, orally), quercetin (0.2 mmol, orally) either alone or in combination, once daily for 5 consecutive days. Arsenic exposure led to a significant depletion of blood delta-aminolevulinic acid dehydratase (ALAD) activity, glutathione, white (WBC) and red blood cell (RBC) counts, and an increase in platelet levels while significantly increasing the level of reactive oxygen species (in RBCs). Hepatic reduced catalase (CAT) and glutathione peroxidase activities showed a depletion, whereas thiobarbituric acid reactive substances (TBARS) levels increased on arsenic exposure indicating arsenite-induced oxidative stress in blood and liver. Kidney CAT activity showed a depletion, whereas TBARS levels increased on arsenic exposure. These biochemical changes were accompanied by an increase in blood, liver, and kidney arsenic concentration. Treatment with MiADMSA was effective in increasing ALAD activity, whereas quercetin was ineffective when given alone. Quercetin when co-administered with MiADMSA also provided no additional beneficial effect on blood ALAD activity but significantly brought altered platelet counts nearer to the normal value. In contrast, administration of quercetin alone provided significant beneficial effects on hepatic oxidative stress and kidney TBARS levels. Renal biochemical variables remained insensitive to arsenic and any of the treatments. Interestingly, combined administration of quercetin with MiADMSA had a remarkable effect in depleting total arsenic concentration from blood and soft tissues. These results lead us to conclude that quercetin administration during chelation treatment had some beneficial effects particularly on the protection of inhibited blood ALAD activity and depletion of arsenic level from target organs. The study supports our earlier conclusion that a co-administration of an antioxidant particularly flavonoids more beneficial than monotherapy with the chelating agents to achieve optimal effects of chelation in arsenite toxicity.
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Affiliation(s)
- Deepshikha Mishra
- Division of Pharmacology and Toxicology, Defense Research and Development Establishment, Jhansi Road, Gwalior, 474 002, India
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In vitro and in vivo reduction of sodium arsenite induced toxicity by aqueous garlic extract. Food Chem Toxicol 2007; 46:740-51. [PMID: 17983699 DOI: 10.1016/j.fct.2007.09.108] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 08/30/2007] [Accepted: 09/25/2007] [Indexed: 01/12/2023]
Abstract
BACKGROUND Arsenic is ubiquitous in the environment, and chronic or acute exposure through food and water as well as occupational sources can contribute to a well-defined spectrum of disease. Despite arsenic being a health hazard and a well-documented human carcinogen, a safe, effective and specific preventive or therapeutic measure for treating arsenic induced toxicity still eludes us. OBJECTIVE This study was undertaken to evaluate the therapeutic efficacy of aqueous garlic (Allium sativum L.) extract (AGE) in terms of normalization of altered biochemical parameters particularly indicative of oxidative stress following sodium arsenite (NaAsO(2)) exposure and depletion of inorganic arsenic burden, in vitro and in vivo. RESULTS AGE (2mg/ml) co-administered with 10 microM NaAsO(2) attenuated arsenite induced cytotoxicity, reduced intracellular reactive oxygen species (ROS) level in human malignant melanoma cells (A375), human keratinocyte cells (HaCaT) and in cultured human normal dermal fibroblast cells. Moreover, AGE application in NaAsO(2) intoxicated Sprague-Dawley rats resulted in a marked inhibition of tissue lipid peroxide generation; enhanced level of total tissue sulfhydryl groups and glutathione; and also increased the activities of antioxidant enzymes, superoxide dismutase and catalase to near normal. An increase in blood ROS level and myeloperoxidase activity in arsenic-intoxicated rats was effectively prevented by AGE administration. AGE was also able to counter arsenic mediated incongruity in blood hematological variables and glucose level. CONCLUSIONS The restorative property of AGE was attributed to its antioxidant activity, chelating efficacy, and/or oxidizing capability of trivalent arsenic to its less toxic pentavalent form. Taken together, evidences indicate that AGE can be a potential protective regimen for arsenic mediated toxicity.
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Modi M, Flora SJS. Combined administration of iron and monoisoamyl-DMSA in the treatment of chronic arsenic intoxication in mice. Cell Biol Toxicol 2007; 23:429-43. [PMID: 17453351 DOI: 10.1007/s10565-007-9005-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Accepted: 02/06/2007] [Indexed: 10/23/2022]
Abstract
Co-administration of iron in combination with monoisoamyl dimercaptosuccinic acid (MiADMSA) against chronic arsenic poisoning in mice was studied. Mice preexposed to arsenic (25 ppm in drinking water for 6 months) mice were treated with MiADMSA (50 mg/kg, intraperitoneally) either alone or in combination with iron (75 or 150 mg/kg, orally) once daily for 5 days. Arsenic exposure led to a significant depletion of blood delta-aminolevulinic acid dehydratase (ALAD) activity, hematocrit, and white blood cell (WBC) counts accompanied by small decline in blood hemoglobin level. Hepatic reduced glutathione (GSH) level, catalase and superoxide dismutase (SOD) activities showed a significant decrease while, oxidized glutathione (GSSG) and thiobarbituric acid-reactive substances (TBARS) levels increased on arsenic exposure, indicating arsenic-induced hepatic oxidative stress. Liver aspartate and alanine transaminases (AST and ALT) activities also decreased significantly on arsenic exposure. Kidney GSH, GSSG, catalase level and SOD activities remained unchanged, while, TBARS level increased significantly following arsenic exposure. Brain GSH, glutathione peroxidase (GPx), and SOD activities decreased, accompanied by a significant elevation of TBARS level after chronic arsenic exposure. Treatment with MiADMSA was marginally effective in reducing ALAD activity, while administration of iron was ineffective when given alone. Iron when co-administered with MiADMSA restored blood ALAD activity. Administration of iron alone had no beneficial effects on hepatic oxidative stress, while in combination with MiADMSA it produced significant decline in hepatic TBARS level compared to the individual effect of MiADMSA. Renal biochemical variables were insensitive to any of the treatments. Combined administration of iron with MiADMSA also had no additional beneficial effect over the individual protective effect of MiADMSA on brain oxidative stress. Interestingly, combined administration of iron with MiADMSA provided more pronounced depletion of blood arsenic, while no additional beneficial effects on tissue arsenic level over the individual effect of MiADMSA were noted. The results lead us to conclude that iron supplementation during chelation has some beneficial effects particularly on heme synthesis pathway and blood arsenic concentration.
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Affiliation(s)
- M Modi
- Division of Pharmacology and Toxicology, Defense Research and Development Establishment, Jhansi Road, Gwalior 474002, India
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Flora S, Pant B, Tripathi N, Kannan G, Jaiswal D. Therapeutic Efficacy of a Few Diesters of Meso 2,3‐Dimercaptosuccinic Acid during Sub‐Chronic Arsenic Intoxication in Rats. J Occup Health 2006. [DOI: 10.1539/joh.39.119] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
| | - B.P. Pant
- Division of ChemistryDefence Research and Development Establishment
| | | | | | - D.K. Jaiswal
- Division of ChemistryDefence Research and Development Establishment
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Hoet P, Buchet JP, Decerf L, Lavalleye B, Haufroid V, Lison D. Clinical evaluation of a lead mobilization test using the chelating agent dimercaptosuccinic acid. Clin Chem 2005; 52:88-96. [PMID: 16239340 DOI: 10.1373/clinchem.2005.051128] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The lead mobilization test reflects the mobilizable and likely toxicologically active fraction of the lead body burden. We propose a safe and convenient protocol for this test, to assess concomitant copper and zinc excretion and to determine the size of the chelatable lead pool in nonoccupationally exposed adults. METHODS The study population included 80 white adults: 40 controls [median blood lead concentration (PbB), 25 microg/L] and 40 lead-exposed individuals (315 microg/L). After collection of 4- and 24-h baseline urine specimens and a blood sample, dimercaptosuccinic acid (DMSA) was administered orally (1 g), and additional 4- and 24-h urine specimens were obtained. Determinants of the chelatable urinary lead (DMSA-PbU) were traced by linear regression analysis. RESULTS Urinary DMSA and lead excretion peaked within 2-3 h after DMSA administration. The amounts of DMSA, lead, copper, and zinc recovered in the 4-h urinary collections were highly correlated with those in 24-h collections (r = 0.857, 0.859, 0.958, and 0.757, respectively). At PbB concentrations >300 microg/L, the relationship between DMSA-PbU and PbB showed a steep increase and a widespread dispersion of DMSA-PbU around the regression line. After DMSA, copper and zinc excretion rates were increased up to 91- and 33-fold, respectively. No side effects were reported after DMSA. CONCLUSIONS Determination of DMSA-PbU in a 4-h collection after DMSA is convenient, apparently safe, and inexpensive. An upper reference limit value of 22 microg/4 h is proposed for Belgian reference individuals. The diagnostic value of DMSA-PbU is likely to be contributive for PbB >300 microg/L.
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Affiliation(s)
- Perrine Hoet
- Unit of Industrial Toxicology and Occupational Medicine, Faculty of Medicine, Catholic University of Louvain, Brussels, Belgium.
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Mehta A, Pant SC, Flora SJS. Monoisoamyl dimercaptosuccinic acid induced changes in pregnant female rats during late gestation and lactation. Reprod Toxicol 2005; 21:94-103. [PMID: 16040228 DOI: 10.1016/j.reprotox.2005.05.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2005] [Revised: 05/17/2005] [Accepted: 05/24/2005] [Indexed: 10/25/2022]
Abstract
Monoisoamyl dimercaptosuccinic acid (MiADMSA), a vicinal thiol chelating agent and an analogue of a conventional metal chelating agent, meso-2,3-dimercaptosuccinic acid (DMSA) has recently been gaining recognition to be more effective chelating agent than DMSA in mobilizing lead, mercury and arsenic. However, very little information is available on the toxicological properties of this chelator. In the present study, MiADMSA was administered to pregnant female rats from day 14 of gestation to day 21 of lactation at different doses through oral (p.o.) and intraperitoneal (i.p.) routes to examine the toxicity in the pups and dams. Results suggested that MiADMSA had no effect on period of gestation, litter-size, sex ratio, and viability and lactation. No skeletal defects were observed following the administration of the chelator. However, MiADMSA administration produced few signs of oxidative stress in dams particularly at the higher doses (100 and 200mg/kg) as evident from increased thiobarbituric acid reactive substances (TBARS) in RBCs and decrease in the delta-aminolevulinic acid dehydratase (ALAD) activity. Administration of MiADMSA also caused some alterations in the essential metal concentration in the soft tissues especially tissue copper loss in lactating mothers and pups, which would be of some concern. Apart from copper, changes were also observed in the tissue zinc concentrations in mothers and pups following MiADMSA administration. The study thus suggests that the chelator is relatively safe during late gestation and it does not cause any major alteration in the mothers and the developing pups. However, detailed studies with MiADMSA, post-toxic metal exposure in pregnant animals may provide useful information.
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Affiliation(s)
- Ashish Mehta
- Department of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474 002, India
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Flora SJS, Mehta A, Rao PVL, Kannan GM, Bhaskar ASB, Dube SN, Pant BP. Therapeutic potential of monoisoamyl and monomethyl esters of meso 2,3-dimercaptosuccinic acid in gallium arsenide intoxicated rats. Toxicology 2004; 195:127-46. [PMID: 14751669 DOI: 10.1016/j.tox.2003.09.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The dose dependent effects of monoisoamyl and monomethyl esters of meso 2,3-dimercaptosuccinic acid (DMSA) (0.1, 0.3 and 0.5 mmol kg(-1), intraperitoneally (i.p.) once daily for 5 days) to offset the characteristic biochemical, immunological, oxidative stress consequences and DNA damage (based on DNA fragmentation and comet assay) following sub-chronic administration of gallium arsenide and the mobilization of gallium and arsenic were examined. The effects of these chelators alone in normal animals too were examined on above-mentioned variables. Male Wistar rats were exposed to 10 mg kg(-1), GaAs, orally once daily for 12 weeks and were administered DMSA or two of its monoesters (monoisoamyl or monomethyl) for 5 consecutive days. DMSA was used as a positive control. DMSA and its derivatives, when given alone, generally have no adverse effects on various parameters. After 5 days of chelation therapy in GaAs pre-exposed rats, MiADMSA was most effective in the reduction of inhibited blood delta-aminolevulinic acid dehydratase (ALAD) activity and zinc protoporphyrin level while, all three chelators effectively reduced urinary ALA excretion, compared to GaAs alone exposed rats. MiADMSA was also effective, particularly at a dose of 0.3 mmol kg(-1), in enhancing the inhibited hepatic transaminase activities. Parameters indicative of oxidative stress responded less favorably to the chelation therapy, however, three chelators significantly restored the altered immunological variables. MiADMSA was relatively more effective than the other two chelators. GaAs produced significant DNA damage in the liver and kidneys and the chelation treatment had moderate but significant influence in reducing DNA damage. All three chelators significantly reduced arsenic concentration and, however, MiADMSA was more effective than the other two chelators in depleting arsenic concentration from blood and other soft tissues. A dose of 0.3 mmol kg(-1) was found to be relatively better than the other two doses examined. Gallium contents of blood and soft tissues remained uninfluenced by the chelation therapy. Significant loss of copper after MiADMSA administration, however, is of concern and requires further exploration. Additionally, further studies are required for the choice of appropriate dose, duration of treatment and possible toxic/side effects. Keeping in view the promising role of MiADMSA in the treatment of GaAs poisoning, these data will be needed for the registration of this chelating agent as licensed drug for the treatment of gallium arsenide intoxication.
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Affiliation(s)
- Swaran J S Flora
- Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Jhansi Road, Gwalior 474002, India.
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Aposhian HV, Morgan DL, Queen HLS, Maiorino RM, Aposhian MM. Vitamin C, glutathione, or lipoic acid did not decrease brain or kidney mercury in rats exposed to mercury vapor. JOURNAL OF TOXICOLOGY. CLINICAL TOXICOLOGY 2003; 41:339-47. [PMID: 12870874 DOI: 10.1081/clt-120022000] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
UNLABELLED Some medical practitioners prescribe GSH and vitamin C alone or in combination with DMPS or DMSA for patients with mercury exposure that is primarily due to the mercury vapor emitted by dental amalgams. HYPOTHESIS This study tested the hypothesis that GSH, vitamin C, or lipoic acid alone or in combination with DMPS or DMSA would decrease brain mercury. METHODS Young rats were exposed to elemental mercury by individual nose cone, at the rate of 4.0 mg mercury per m3 air for 2 h per day for 7 consecutive days. After a 7-day equilibrium period, DMPS, DMSA, GSH, vitamin C, lipoic acid alone, or in combination was administered for 7 days and the brain and kidneys of the animals removed and analyzed for mercury by cold vapor atomic absorption. RESULTS None of these regimens reduced the mercury content of the brain. Although DMPS or DMSA was effective in reducing kidney mercury concentrations, GSH, vitamin C, lipoic acid alone, or in combination were not. CONCLUSION One must conclude that the palliative effect, if any, of GSH, vitamin C, or lipoic acid for treatment of mercury toxicity due to mercury vapor exposure does not involve mercury mobilization from the brain and kidney.
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Affiliation(s)
- H Vasken Aposhian
- Department of Molecular and Cellular Biology, The University of Arizona, Tucson, Arizona 85721-0106, USA.
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26
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Kostial K, Restek-Samar?ija N, Piasek M, Varnai VM, Blanu?a M, Jones MM, Singh PK. Combined treatment withracemic-DMSA and EDTA for lead mobilization in rats. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/1520-670x(2000)13:3<277::aid-jtra5>3.0.co;2-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
This review is Part I of a two-part series focusing on heavy metal toxicity. Part I will cover arsenic and mercury toxicity. Acute and chronic arsenic toxicity, as well as arsine gas toxicity, will be reviewed. The clinical presentation, with focus on the nervous, cardiovascular, pulmonary, gastrointestinal, hepatic, renal, hematopoietic, and dermatologic systems, is delineated. Mercury exposure, including exposure to short chain alkyl mercury, elemental mercury, and acute inorganic salt, is reviewed. The discussion of clinical toxicity focuses on the nervous, cardiovascular, pulmonary, gastrointestinal, and renal systems, as well as on the teratogenic effects of mercury. Recommendations for diagnostic tests and management plans are discussed, including chelation regimens.
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Affiliation(s)
- K A Graeme
- Department of Emergency Medicine, Maricopa Medical Center, Phoenix, Arizona, USA
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28
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Grandjean P, Guldager B, Larsen IB, Jørgensen PJ, Holmstrup P. Placebo response in environmental disease. Chelation therapy of patients with symptoms attributed to amalgam fillings. J Occup Environ Med 1997; 39:707-14. [PMID: 9273873 DOI: 10.1097/00043764-199708000-00004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Treatment of patients who attribute their environmental illness to mercury from amalgam fillings is largely experimental. On the Symptom Check List, overall distress, and somatization, obsessive-compulsive, depression, and anxiety symptom dimensions, were increased in 50 consecutive patients examined, and Eysenck Personality Questionnaire scores suggested less extroversion and increased degree of emotional liability. Succimer (meso-2, 3-dimercaptosuccinic acid) was given at a daily dose of 30 mg/kg for five days in a double-blind, randomized placebo-controlled trial. Urinary excretion of mercury and lead was considerably increased in the patients who received the chelator. Immediately after the treatment and 5 to 6 weeks later, most distress dimensions had improved considerably, but there was no difference between the succimer and placebo groups. These findings suggest that some patients with environmental illness may substantially benefit from placebo.
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Affiliation(s)
- P Grandjean
- Department of Environmental Medicine, Odense University, Denmark
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29
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Keith RL, Setiarahardjo I, Fernando Q, Aposhian HV, Gandolfi AJ. Utilization of renal slices to evaluate the efficacy of chelating agents for removing mercury from the kidney. Toxicology 1997; 116:67-75. [PMID: 9020508 DOI: 10.1016/s0300-483x(96)03531-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Mercury is an environmental contaminant that preferentially accumulates in the kidney. It has been previously shown using proton-induced X-ray emission analysis that mercury (HgCl2) accumulated in precision-cut rabbit renal cortical slices. In this study, the efficacy of seven chelating agents for the removal of Hg from renal slices has been examined. Rabbits were injected with HgCl2 (10 mg/kg) and 3 h later kidneys were sliced, or renal slices were exposed in vitro to a mildly toxic concentration of HgCl2 (5 x 10(-5)M, 4 h). The slices were then treated in vitro with 10 mM concentrations of EDTA, lipoic acid (LA), penicillamine (PA), glutathione (GSH), 1,4-dithiothreitol (DTT), DMSA, or DMPS. DMPS proved to be the most effective in mobilizing Hg from in vivo or in vitro HgCl2-exposed renal tissue ( > 85% of control after 3 h incubation). Relative efficacies for the seven agents were DMPS > DMSA, PA > DTT, GSH > LA, EDTA. The use of renal slices appears to be a useful in vitro tool for assessing the efficacy of chelating agents on mobilizing accumulated Hg from renal tissue.
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Affiliation(s)
- R L Keith
- Center for Toxicology, The University of Arizona, Tucson 85721, USA
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30
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Aposhian MM, Maiorino RM, Xu Z, Aposhian HV. Sodium 2,3-dimercapto-1-propanesulfonate (DMPS) treatment does not redistribute lead or mercury to the brain of rat. Toxicology 1996; 109:49-55. [PMID: 8619252 DOI: 10.1016/0300-483x(96)03308-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Since there has been concern about whether any of the chelating agents used therapeutically might cause an initial redistribution of heavy metals to the brain and since the sodium salt of 2,3-dimercapto-1-propanesulfonic acid (Dimaval, DMPS) has been used to treat heavy metal intoxication in humans, the hypothesis that DMPS does not redistribute and increase lead or mercuric ions in the brains of rats was tested. Lead acetate at a concentration of 50 mg/l was made available in the drinking water of rats for 86 days. Other rats received intraperitoneal injections of 0.50 mg Hg/kg (as mercuric chloride) each day for 5 days a week for a total of 32 or 41 days. Animals were divided into groups and given, i.p., either 0.27 mmol DMPS/kg body weight or saline, each day for 1, 2, 3 or 4 days. Lead or mercury concentrations of the brain were determined after each group received DMPS for the different number of days. DMPS treatment did not result in any initial increase of lead or mercuric ions in the brain. The mercury content of the kidney decreased. The results of these experiments demonstrated that lead or mercuric ions were not redistributed to or increased in the brains of rats during the initial days of DMPS treatment.
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Affiliation(s)
- M M Aposhian
- Department of Molecular and Cellular Biology, University of Arizona, Tuscon, AZ 85721, USA
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31
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Bellés M, Sánchez DJ, Gómez M, Domingo JL, Jones MM, Singh PK. Assessment of the protective activity of monisoamyl meso-2,3-dimercaptosuccinate against methylmercury-induced maternal and embryo/fetal toxicity in mice. Toxicology 1996; 106:93-7. [PMID: 8571406 DOI: 10.1016/0300-483x(95)03167-e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The protective activity of monoisoamyl meso-2,3-dimercaptosuccinate (Mi-ADMS), a new monoester of 2,3-dimercaptosuccinic acid (DMSA), on methylmercury-induced maternal and developmental toxicity was assessed in mice. A series of four Mi-ADMS injections was given s.c. at 0.25, 6, 24, and 48 h after oral administration of 25 mg/kg of methylmercury chloride (MMC) given on day 10 of gestation. Mi-ADMS effectiveness was tested at 0, 23.8, 47.6 and 95 mg/kg. Cesarean sections were performed on gestation day 18. All live fetuses were examined for external, internal, and skeletal abnormalities. Oral MMC administration resulted in an increase in the number of resorptions, and a decrease in fetal body weight, whereas the incidence of cleft palate, micrognathia, and skeletal variations was also increased in the fetuses of the MMC-treated groups. Although significant amelioration of MMC-induced embryolethality by Mi-ADMS was not noted at any dose, MMC-induced fetotoxicity was reduced by administration of this agent at 23.8, 47.6, and 95 mg/kg. However, the intrinsic toxicity of Mi-ADMS would be a restrictive factor for the possible therapeutic use of this chelator in pregnant women exposed to organic mercury.
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Affiliation(s)
- M Bellés
- Laboratory of Toxicology and Biochemistry, School of Medicine, Rovira i Virgili University, Reus, Spain
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32
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Aposhian HV, Maiorino RM, Gonzalez-Ramirez D, Zuniga-Charles M, Xu Z, Hurlbut KM, Junco-Munoz P, Dart RC, Aposhian MM. Mobilization of heavy metals by newer, therapeutically useful chelating agents. Toxicology 1995; 97:23-38. [PMID: 7716789 DOI: 10.1016/0300-483x(95)02965-b] [Citation(s) in RCA: 190] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Four chelating agents that have been used most commonly for the treatment of humans intoxicated with lead, mercury, arsenic or other heavy metals and metalloids are reviewed as to their advantages, disadvantages, metabolism and specificity. Of these, CaNa2EDTA and dimercaprol (British anti-lewisite, BAL) are becoming outmoded and can be expected to be replaced by meso-2,3-dimercaptosuccinic acid (DMSA, succimer) for treatment of lead intoxication and by the sodium salt of 2,3-dimercapto-1-propanesulfonic acid (DMPS, Dimaval) for treating lead, mercury or arsenic intoxication. Meso-2,3-DMSA and DMPS are biotransformed differently in humans. More than 90% of the DMSA excreted in the urine is found in the form of a mixed disulfide in which each of the sulfur atoms of DMSA is in disulfide linkage with an L-cysteine molecule. After DMPS administration, however, acyclic and cyclic disulfides of DMPS are found in the urine. The Dimaval-mercury challenge test holds great promise as a diagnostic test for mercury exposure, especially for low level mercurialism. Urinary mercury after Dimaval challenge may be a better biomarker of low level mercurialism than unchallenged urinary mercury excretion.
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Affiliation(s)
- H V Aposhian
- Department of Molecular and Cellular Biology, University of Arizona, Tucson 85721, USA
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Aaseth J, Jacobsen D, Andersen O, Wickstrøm E. Treatment of mercury and lead poisonings with dimercaptosuccinic acid and sodium dimercaptopropanesulfonate. A review. Analyst 1995; 120:853-4. [PMID: 7741240 DOI: 10.1039/an9952000853] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- J Aaseth
- Medical Department, Kongsvinger Hospital, Norway
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Endo T, Sakata M. Effects of sulfhydryl compounds on the accumulation, removal and cytotoxicity of inorganic mercury by primary cultures of rat renal cortical epithelial cells. PHARMACOLOGY & TOXICOLOGY 1995; 76:190-5. [PMID: 7617544 DOI: 10.1111/j.1600-0773.1995.tb00128.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effects of sulfhydryl compounds on the accumulation, removal and cytotoxicity of inorganic mercury (Hg) were investigated in primary cultures of rat renal cortical epithelial cells. The compounds investigated were 2,3-dimercaptosuccinic acid, 2,3-dimercapto-1-propanol, D-penicillamine, glutathione (GSH) and L-cysteine. In the accumulation experiment, the cells were co-incubated with Hg and the above compounds for 30 min. (short-term) or 18 hr (long-term). In the removal experiment, cells incubated with Hg were further incubated with the above compounds for 30 min. In both experiments, the alleviative effect of the compounds on the cytotoxicity was estimated by the uptake of neutral red or by cell growth. 2,3-Dimercaptosuccinic acid had the highest antidotal effects except for Hg removal. 2,3-Dimercapto-1-propanol exerted the least antidotal effects in the short-term, as well as in the long-term experiments, 2,3-dimercapto-1-propanol increased the Hg accumulation and the cytotoxicity despite its removal of most of the Hg. Although D-penicillamine, L-cysteine and GSH did not increase the Hg removal in the long-term experiment other antidotal effects were seen.
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Affiliation(s)
- T Endo
- Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Japan
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35
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Flora SJ, Mathur S, Mathur R. Effects of meso-2,3-dimercaptosuccinic acid or 2,3-dimercaptopropane 1-sulfonate on beryllium-induced biochemical alterations and metal concentration in male rats. Toxicology 1995; 95:167-75. [PMID: 7825183 DOI: 10.1016/0300-483x(94)02903-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The effects of two chelating agents, meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercaptopropane 1-sulfonate (DMPS) on the mobilization, distribution, hepatic and hematopoietic toxicity of beryllium were compared in male rats exposed to beryllium. Animals were exposed to beryllium nitrate (0.5 mg/kg, orally, daily 5 days/week) for 21 days. Twenty-four hours after the last dose they were injected with a chelating agent (DMSA or DMPS) (25 or 50 mg/kg, twice daily for 5 days). The administration of DMSA and DMPS at a dose of 50 mg/kg marginally elevated the fecal excretion of beryllium. DMPS was effective in depleting beryllium from the liver, spleen and kidneys. However, DMPS (50 mg/kg) results in the redistribution of beryllium to blood. Beryllium-induced inhibition of hepatic alkaline phosphatase and hepatic adenosine triphosphatase (ATPase) were restored considerably with the chelating agents. Also, hepatic and renal histopathological lesions were less marked in rats treated with DMPS (50 mg/kg) compared with those treated with beryllium per se and DMSA. These effects were more prominent at the 50-mg/kg dose of chelating agents than at 25 mg/kg. These results suggest that treatment with DMPS has some beneficial effects in experimental beryllium intoxication.
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Affiliation(s)
- S J Flora
- Division of Pharmacology and Toxicology, Defence Research and Development Establishment, Gwalior, India
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36
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Bosque MA, Domingo JL, Corbella J, Jones MM, Singh PK. Developmental toxicity evaluation of monoisoamyl meso-2,3-dimercaptosuccinate in mice. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1994; 42:443-50. [PMID: 8051718 DOI: 10.1080/15287399409531894] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Monoisoamyl meso-2,3-dimercaptosuccinate (Mi-ADMS), a new dimercaptosuccinic acid (DMSA) analog with enhanced lipophilic properties, was evaluated for potential developmental toxicity. Intraperitoneal injections of Mi-ADMS were given to female Swiss mice (0, 47.5, 95, and 190 mg/kg) on gestational d 6-15. The maternal clinical status was monitored daily during treatment. At termination (gestational d 18), dams were evaluated for clinical status and gestational outcome. Each live fetus was weighed and examined for external, visceral, and skeletal abnormalities. Although no maternal mortality was observed, treatment with 95 and 190 mg/kg resulted in maternal toxicity, manifested as reduced body weight gain during treatment and increased relative liver weight. Embryo/fetal toxicity, consisting of a significant increase in the number of late resorptions as well as in the percentage of postimplantation loss, reduced (nonsignificant) fetal body weight, and an increase in the incidence of skeletal defects, was also observed at 190 mg/kg/d. However, no treatment-related external or soft-tissue malformations or developmental variations were found in any group. The no-observed-adverse-effect level (NOAEL) for maternal toxicity was 47.5 mg/kg/d, whereas the NOAEL for developmental toxicity was 95 mg/kg/d. These results indicate that Mi-ADMS did not produce developmental toxicity in mice in the absence of maternal toxicity.
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Affiliation(s)
- M A Bosque
- Laboratory of Toxicology and Biochemistry, School of Medicine, Rovira i Virgili University, Reus, Spain
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Sandborgh Englund G, Dahlqvist R, Lindelöf B, Söderman E, Jonzon B, Vesterberg O, Larsson KS. DMSA administration to patients with alleged mercury poisoning from dental amalgams: a placebo-controlled study. J Dent Res 1994; 73:620-8. [PMID: 8163732 DOI: 10.1177/00220345940730030701] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The present investigation was performed to determine the effect of 14-day oral administration of meso-2.3-dimercaptosuccinic acid (DMSA) on the urinary mercury excretion and the potential reduction of blood and plasma mercury concentrations, and also to relate these effects to possible decrease of symptoms, allegedly associated with amalgam fillings. Twenty subjects, relating their symptoms to mercury from amalgam fillings, received 20 mg/kg DMSA or placebo for 14 days. Their symptoms and mood states were recorded during the study and at a check-up 3 months later. Interpretation was based on intra-individual differences. DMSA-treatment resulted in an average increase in urinary mercury excretion by 65% and a decrease in blood mercury levels of 0.04 microgram/L/day. At the check-up after 3 months, urinary mercury excretion had returned to the pre-treatment level. No treatment effect of DMSA was apparent on subjective symptoms and mood state. One statistically significant treatment effect was noted-a decrease in fatigue-inertia in the DMSA-group-but there was no demonstrable correlation with increased urinary excretion or decreased blood concentration of mercury. Three subjects showed hypersensitive reactions, probably DMSA-specific, at the end of the treatment period. This placebo-controlled study provides no scientific support for diagnostic or therapeutic administration of DMSA for symptoms allegedly associated with chronic mercury exposition from dental amalgam fillings.
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Affiliation(s)
- G Sandborgh Englund
- Department of Odontological Toxicology, Karolinska Institute, Huddinge, Sweden
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Yokel RA. Aluminum chelation: chemistry, clinical, and experimental studies and the search for alternatives to desferrioxamine. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1994; 41:131-74. [PMID: 8301696 DOI: 10.1080/15287399409531834] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This review focuses on aluminum (Al) chelation, its chemistry and biology. The toxicology and biology of Al in mammalian organisms are briefly reviewed to introduce the problems associated with excessive Al exposure and accumulation and the challenges facing an effective Al chelator. The basics of Al chelation chemistry are considered to help the reader understand the Al chelation chemical literature. The chemical properties of Al enable prediction of effective functional groups for Al chelation. A compilation of distribution coefficients between octanol and aqueous phases (Do/a) for chelators and their complexes with Al shows the effect of complexation on lipophilicity. A compilation of stability constants for Al.chelator complexes illustrates the role of oxygen in ligands that form stable complexes. The history of clinical Al chelation therapy is reviewed, with emphasis on desferrioxamine (DFO), which has been extensively used since 1980. The beneficial and adverse effects and limitations of DFO use in end-stage renal-diseased patients, in patients with neurodegenerative disorders, including Alzheimer's disease, and in animal models of Al intoxication are presented. The methods to evaluate potential Al chelators in vitro, in vivo, and using computer modeling are discussed. The Al chelation literature is reviewed by the chemical class of chelators, including fluoride, carboxylic acids, amino acids, catechols, polyamino carboxylic acids, phenyl carboxylic acids, the hydroxypyridinones, and hydroxamic acids.
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Affiliation(s)
- R A Yokel
- Division of Pharmacology and Experimental Therapeutics, College of Pharmacy, University of Kentucky, Lexington
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Walker EM, Stone A, Milligan LB, Gale GR, Atkins LM, Smith AB, Jones MM, Singh PK, Basinger MA. Mobilization of lead in mice by administration of monoalkyl esters of meso-2,3-dimercaptosuccinic acid. Toxicology 1992; 76:79-87. [PMID: 1335621 DOI: 10.1016/0300-483x(92)90020-f] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The following six monoalkyl esters of meso-2,3-dimercaptosuccinic acid (DMSA) were synthesized and evaluated for relative activities in mobilizing lead from kidneys and brains of lead-bearing mice: n-propyl (Mn-PDMS), i-propyl (Mi-PDMS), n-butyl (Mn-BDMS), i-butyl (Mi-BDMS), n-amyl (Mn-ADMS) and i-amyl meso-2,3-dimercaptosuccinate (Mi-ADMS). DMSA was used as a positive control. When each was administered intraperitoneally (i.p.) as a single dose of 2.0 mmol/kg, DMSA lowered the kidney lead concentration 52%, while the monoesters effected reductions of 54-75%. Mn-ADMS was toxic at this dose. DMSA lowered the brain lead level 20% when given as a single dose, while the monoesters conferred reductions of 64-87%. When given as 5 daily i.p. injections at 0.5 mmol/kg, DMSA reduced the kidney lead concentration 45%, while the monoesters caused reductions of 56-73%. DMSA lowered the brain lead concentration 35% on the 5-day treatment regimen, while the monoesters evoked reductions of 59-75%. Mi-ADMS was equally effective when given orally or i.p. The i.p. LD50 value of this analog in mice is 3.0 mmol/kg, a value which lies between the reported LD50 doses of DMSA (16.0 mmol/kg) and dimercaprol (1.1 mmol/kg). It is suggested that the ability of these monoesters to cross cell membranes may account for their superiority to DMSA in mobilizing brain lead in this animal model.
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Affiliation(s)
- E M Walker
- John L. McClellan Memorial Department of Veterans Affairs Medical Center, Little Rock, AR
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Graziano JH, Lolacono NJ, Moulton T, Mitchell ME, Slavkovich V, Zarate C. Controlled study of meso-2,3-dimercaptosuccinic acid for the management of childhood lead intoxication. J Pediatr 1992; 120:133-9. [PMID: 1309865 DOI: 10.1016/s0022-3476(05)80618-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We examined the efficacy and safety of meso-2,3-dimercaptosuccinic acid (DMSA) in children with markedly elevated blood lead (BPb) concentrations. Among 19 children with BPb concentrations of 50 to 69 micrograms/dl (2.41 to 3.33 mumol/L) who received a 5-day inpatient oral course of DMSA (1050 mg/m2 per day), the mean BPb concentration decreased by 61%; in four who received calcium disodium ethylenediaminetetraacetic acid (CaNa2EDTA) (1000 mg/m2 per day intravenously), it decreased by 45% (p less than 0.0007). Urinary lead excretion was comparable in both groups. Treatment with DMSA was more effective than treatment with CaNa2EDTA in restoring metabolic activity to the heme pathway and was well tolerated even among nine patients who received concomitant iron supplementation and two who had homozygous deficiency of glucose-6-phosphate dehydrogenase. On discharge, these 19 children received either no chelation therapy or DMSA, 350 or 700 mg/m2 per day for 14 days on an outpatient basis. After 14 days the mean BPb values for the no-chelation, low-DMSA, and high-DMSA groups were 73%, 66%, and 50% of the pretreatment values, respectively. We conclude that a 5-day oral course of DMSA is effective in the treatment of children with severe lead poisoning. In addition, on an outpatient basis the administration of DMSA, 700 mg/m2 per day, is capable of delaying the typical rebound in BPb values and should ultimately reduce the need for repeated hospitalizations.
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Affiliation(s)
- J H Graziano
- Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, New York
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Jacobsen D. Research aspects in clinical toxicology. ARCHIVES OF TOXICOLOGY. SUPPLEMENT. = ARCHIV FUR TOXIKOLOGIE. SUPPLEMENT 1992; 15:20-5. [PMID: 1510589 DOI: 10.1007/978-3-642-77260-3_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- D Jacobsen
- Department of Medicine, Ullevål University Hospital
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