scispace - formally typeset

Journal Article

Dimercaptosuccinic Acid (DMSA), A Non-Toxic, Water-Soluble Treatment For Heavy Metal Toxicity

01 Jun 1998-Alternative medicine review : a journal of clinical therapeutic (Altern Med Rev)-Vol. 3, Iss: 3, pp 199-207

TL;DR: DMSA is a sulfhydryl-containing, water-soluble, non-toxic, orally-administered metal chelator which has been in use as an antidote to heavy metal toxicity since the 1950s and is established as the premier metal chelation compound, based on oral dosing, urinary excretion, and its safety characteristics compared to other chelating substances.

AbstractHeavy metals are, unfortunately, present in the air, water, and food supply. Cases of severe acute lead, mercury, arsenic, and cadmium poisoning are rare; however, when they do occur an effective, non-toxic treatment is essential. In addition, chronic, low-level exposure to lead in the soil and in residues of lead-based paint; to mercury in the atmosphere, in dental amalgams and in seafood; and to cadmium and arsenic in the environment and in cigarette smoke is much more common than acute exposure. Meso-2,3-dimercaptosuccinic acid (DMSA) is a sulfhydryl-containing, water-soluble, non-toxic, orally-administered metal chelator which has been in use as an antidote to heavy metal toxicity since the 1950s. More recent clinical use and research substantiates this compound’s efficacy and safety, and establishes it as the premier metal chelation compound, based on oral dosing, urinary excretion, and its safety characteristics compared to other chelating substances. (Altern Med Rev 1998;3(3):199-207)

Topics: Metal toxicity (62%), Dimercaptosuccinic acid (54%), Cadmium poisoning (53%), Cadmium (52%), Mercury (element) (51%)

...read more

Content maybe subject to copyright    Report

Citations
More filters

Journal ArticleDOI

[...]

01 Apr 2011-BMJ

729 citations


Journal ArticleDOI
TL;DR: This review provides an update of the existing chelating agents and the various strategies available for the treatment of heavy metals and metalloid intoxications.
Abstract: Chelation therapy is the preferred medical treatment for reducing the toxic effects of metals. Chelating agents are capable of binding to toxic metal ions to form complex structures which are easily excreted from the body removing them from intracellular or extracellular spaces. 2,3-Dimercaprol has long been the mainstay of chelation therapy for lead or arsenic poisoning, however its serious side effects have led researchers to develop less toxic analogues. Hydrophilic chelators like meso-2,3-dimercaptosuccinic acid effectively promote renal metal excretion, but their ability to access intracellular metals is weak. Newer strategies to address these drawbacks like combination therapy (use of structurally different chelating agents) or co-administration of antioxidants have been reported recently. In this review we provide an update of the existing chelating agents and the various strategies available for the treatment of heavy metals and metalloid intoxications.

638 citations


Cites background from "Dimercaptosuccinic Acid (DMSA), A N..."

  • ...The drug is 95 % plasma protein bound, most likely by virtue of binding on one of its sulfhydryl groups to a cysteine residue on albumin, leaving the other –SH available to chelate metals [39]....

    [...]


Journal ArticleDOI
TL;DR: Superparamagnetic iron oxide (Fe3O4) nanoparticles with a surface functionalization of dimercaptosuccinic acid (DMSA) are an effective sorbent material for toxic soft metals such as Hg, Ag, Pb, Cd, and Tl, which effectively bind to the DMSA ligands and for As, which binds to the iron oxide lattices.
Abstract: We have shown that superparamagnetic iron oxide (Fe3O4) nanoparticles with a surface functionalization of dimercaptosuccinic acid (DMSA) are an effective sorbent material for toxic soft metals such as Hg, Ag, Pb, Cd, and Tl, which effectively bind to the DMSA ligands and for As, which binds to the iron oxide lattices. The nanoparticles are highly dispersible and stable in solutions, have a large surface area (114 m2/g), and have a high functional group content (1.8 mmol thiols/g). They are attracted to a magnetic field and can be separated from solution within a minute with a 1.2 T magnet. The chemical affinity, capacity, kinetics, and stability of the magnetic nanoparticles were compared to those of conventional resin based sorbents (GT-73), activated carbon, and nanoporous silica (SAMMS) of similar surface chemistries in river water, groundwater, seawater, and human blood and plasma. DMSA-Fe3O4 had a capacity of 227 mg of Hg/g, a 30-fold larger value than GT-73. The nanoparticles removed 99 wt % of 1 mg...

583 citations


Journal ArticleDOI
TL;DR: Considerable attention was given in this review to pediatric methylmercury exposure and neurodevelopment because it is the most thoroughly investigated Hg species.
Abstract: Exposure to toxic mercury (Hg) is a growing health hazard throughout the world today. Recent studies show that mercury exposure may occur in the environment, and increasingly in occupational and domestic settings. Children are particularly vulnerable to Hg intoxication, which may lead to impairment of the developing central nervous system, as well as pulmonary and nephrotic damage. Several sources of toxic Hg exposure in children have been reported in biomedical literature: (1) methylmercury, the most widespread source of Hg exposure, is most commonly the result of consumption of contaminated foods, primarily fish; (2) ethylmercury, which has been the subject of recent scientific inquiry in relation to the controversial pediatric vaccine preservative thimerosal; (3) elemental Hg vapor exposure through accidents and occupational and ritualistic practices; (4) inorganic Hg through the use of topical Hg-based skin creams and in infant teething powders; (5) metallic Hg in dental amalgams, which release Hg vapors, and Hg 2+ in tissues. This review examines recent epidemiological studies of methylmercury exposure in children. Reports of elemental Hg vapor exposure in children through accidents and occupational practices, and the more recent observations of the increasing use of elemental Hg for magico-religious purposes in urban communities are also discussed. Studies of inorganic Hg exposure from the widespread use of topical beauty creams and teething powders, and fetal/neonatal Hg exposure from maternal dental amalgam fillings are reviewed. Considerable attention was given in this review to pediatric methylmercury exposure and neurodevelopment because it is the most thoroughly investigated Hg species. Each source of Hg exposure is reviewed in relation to specific pediatric health effects, particularly subtle neurodevelopmental disorders.

447 citations


Cites background from "Dimercaptosuccinic Acid (DMSA), A N..."

  • ...They found highly elevated pretreatment Hg levels in urine, which they reduced therapeutically with a succimer (DMSA) treatment regimen (Forman et al., 2000; Miller, 1998)....

    [...]


Journal Article
TL;DR: Basic research pertaining to the transport of toxic metals into the brain is summarized, and a case is made for the use of hydrolyzed whey protein to support metal detoxification and neurological function.
Abstract: Chronic, low level exposure to toxic metals is an increasing global problem. The symptoms associated with the slow accumulation of toxic metals are multiple and rather nondescript, and overt expression of toxic effects may not appear until later in life. The sulfhydryl-reactive metals (mercury, cadmium, lead, arsenic) are particularly insidious and can affect a vast array of biochemical and nutritional processes. The primary mechanisms by which the sulfhydryl-reactive metals elicit their toxic effects are summarized. The pro-oxidative effects of the metals are compounded by the fact that the metals also inhibit antioxidative enzymes and deplete intracellular glutathione. The metals also have the potential to disrupt the metabolism and biological activities of many proteins due to their high affinity for free sulfhydryl groups. Cysteine has a pivotal role in inducible, endogenous detoxication mechanisms in the body, and metal exposure taxes cysteine status. The protective effects of glutathione and the metallothioneins are discussed in detail. Basic research pertaining to the transport of toxic metals into the brain is summarized, and a case is made for the use of hydrolyzed whey protein to support metal detoxification and neurological function. Metal exposure also affects essential element status, which can further decrease antioxidation and detoxification processes. Early detection and treatment of metal burden is important for successful detoxification, and optimization of nutritional status is paramount to the prevention and treatment of metal toxicity.

281 citations


References
More filters

Journal ArticleDOI
TL;DR: This article reviews the pharmacological properties and the uses of two important antidotes for heavy metal poisoning, DMSA and DMPS, water soluble chemical analogs of dimercaprol, which have less toxicity, greater water solubility, and lim­ ited lipid solubilities, and are effective when given orally.
Abstract: This article reviews the pharmacological properties and the uses of two important antidotes for heavy metal poisoning. Meso-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-l-propanesulfonic acid, Na salt (DMPS) are relatively new antidotes-new, that is, to the western world. Although DMSA was introduced originally by Friedheim et al (1) to increase uptake of antimony during schistosomiasis therapy, Liang et al (77) at Shanghai in 1957 were the first to report its effectiveness as an antidote for heavy metal poisoning. The synthesis and some of the metal binding properties of DMPS were reported in 1956 by Petrunkin from Kiev (3). Shortly thereaf­ ter, DMPS became an official drug in the Soviet Union, where it is known as Unithiol (4). Between 1956 and 1975, DMSA and DMPS were studied extensively, at both the basic science and clinical levels, in the People's Republic of China, the Soviet Union, and Japan. Some of these investigations have been cited and can be found in an earlier review (5). In the USA and western Europe, however, these two compounds received very little attention until recently. A paper by Friedheim & Corvi (6) in 1975, dealing with DMSA for the treatment of mercury poisoning, and the recent production and availability of DMPS from Heyl & Co., Berlin, stimulated investigators to "rediscover" and study these two metal-binding agents. DMSA and DMPS are water soluble chemical analogs of dimercaprol (British Anti-Lewisite, BAL). In contrast to BAL, they have less toxicity, greater water solubility, and lim­ ited lipid solubility, and are effective when given orally.

301 citations


"Dimercaptosuccinic Acid (DMSA), A N..." refers background in this paper

  • ...DMSA has been shown in recent studies to be a safe and effective chelator of lead, reducing blood levels significantly.(1,34,35) At a dose of 10 mg/kg for five days in adult males, DMSA lowered blood lead levels 35....

    [...]

  • ...DMSA was subsequently studied for twenty years in the People’s Republic of China, Japan, and Russia before scientists in Europe and the United States “discovered” the substance and its potential usefulness in the mid-1970s.(1) DMSA is a dithiol (containing two sulfhydryl, or S-H, groups) and an analogue of dimercaprol (BAL, British Anti-Lewisite), a lipid-soluble compound also used for metal chelation (see Figure 1)....

    [...]


Journal ArticleDOI
TL;DR: Analysis of the data from the questionnaires indicated that little or no exogenous exposure to mercury occurred among the two groups.
Abstract: Mercury levels in blood and in mouth air before and after chewing were measured in 47 persons with ana 14 persons without dental amalgam restorations. Questionnaires relating to exogenous sources of mercury exposure were administered to both groups. Differences in the mouth air mercury levels before and after chewing were statistically significant in the group with amalgams, but not in the group without amalgams. Analysis of the data from the questionnaires indicated that little or no exogenous exposure to mercury occurred among the two groups. Blood mercury concentrations were positively correlated with the number and surface area of amalgam restorations and were significantly lower in the group without dental amalgams.

190 citations


Journal ArticleDOI
TL;DR: It has been discovered that microtubules are destroyed by this form of mercury and this effect may explain the inhibition of cell division and cell migration, processes that occur only in the developmental stages, and other hypotheses will stimulate considerable experimental challenges in the future.
Abstract: The nervous system is the principal target for a number of metals. Inorganic compounds of aluminum, arsenic, lead, lithium, manganese, mercury, and thallium are well known for their neurological and behavioral effects in humans. The alkyl derivatives of certain metals--lead, mercury and tin--are specially neurotoxic. Concern over human exposure and in some cases, outbreaks of poisoning, have stimulated research into the toxic action of these metals. A number of interesting hypotheses have been proposed for the mechanism of lead toxicity on the nervous system. Lead is known to be a potent inhibitor of heme synthesis. A reduction in heme-containing enzymes could compromise energy metabolism. Lead may affect brain function by interference with neurotransmitters such as gamma-amino-isobutyric acid. There is mounting evidence that lead interferes with membrane transport and binding of calcium ions. Methylmercury produces focal damage to specific areas in the adult brain. One hypothesis proposes that certain cells are susceptible because they cannot repair the initial damage to the protein sythesis machinery. The developing nervous system is especially susceptible to damage by methylmercury. It has been discovered that microtubules are destroyed by this form of mercury and this effect may explain the inhibition of cell division and cell migration, processes that occur only in the developmental stages. These and other hypotheses will stimulate considerable experimental challenges in the future.

184 citations


"Dimercaptosuccinic Acid (DMSA), A N..." refers background in this paper

  • ...Methyl mercury also easily crosses the blood-brain barrier and the placenta.(7) Inorganic and methyl mercury have a high affinity for sulfhydryls, reacting intracellularly with the sulfhydryl group on glutathione and cysteine, and histidine residues in proteins, and allowing transport out of the cell....

    [...]

  • ...After lead is absorbed in the human body, it reacts with thiol (sulfhydryl) groups on peptides and proteins, inhibiting enzymes involved in heme synthesis and interfering with normal neurotransmitter functions.(7) This natural reaction with thiols is also the body’s method of eliminating lead, especially from the liver....

    [...]


Journal ArticleDOI
TL;DR: Animal and human experiments demonstrate that the uptake, tissue distribution, and excretion of amalgam Hg is significant, and that dental amalgam is the major contributing source to Hg body burden in humans.
Abstract: For more than 160 years dentistry has used silver amalgam, which contains approximately 50% Hg metal, as the preferred tooth filling material. During the past decade medical research has demonstrated that this Hg is continuously released as vapor into mouth air; then it is inhaled, absorbed into body tissues, oxidized to ionic Hg, and finally covalently bound to cell proteins. Animal and human experiments demonstrate that the uptake, tissue distribution, and excretion of amalgam Hg is significant, and that dental amalgam is the major contributing source to Hg body burden in humans. Current research on the pathophysiological effects of amalgam Hg has focused upon the immune system, renal system, oral and intestinal bacteria, reproductive system, and the central nervous system. Research evidence does not support the notion of amalgam safety.

169 citations


Journal ArticleDOI
TL;DR: Results suggest that lead-induced oxidative stress in vivo can be mitigated by pharmacologic interventions, which encompass both chelating as well as thiol-mediated antioxidant functions.
Abstract: Knowledge of lead's capacity to disrupt the prooxidant/antioxidant balance within mammalian tissues suggests that definitive therapy for chronic lead poisoning should encompass both chelating and antioxidant actions. The dithiol meso-2,3-Dimercaptosuccinic Acid (DMSA) is the first orally administered metal chelating agent to receive U.S. Food and Drug Administration (FDA) approval for the treatment of childhood plumbism and possesses the potential to function as an antioxidant by removing lead from the site of deleterious oxidation reactions. Five weeks of lead exposure was found to deplete glutathione (GSH) levels, increase oxidized glutathione (GSSG), and promote malondialdehyde (MDA) production in both liver and brain samples taken from C57BL/6 mice. GSH levels increased and GSSG and MDA levels decreased in groups of lead-exposed mice that received 1 mmol/kg DMSA or 5.5 mmol/kg N-acetylcysteine (NAC) for 7 d prior to sacrifice. Treatment with DMSA caused a reduction in blood, liver, and brain lead levels consistent with its function as a chelating agent, while treatment with NAC did not reduce these lead levels. However, NAC did cause a reduction in indices of oxidative stress in both brain and liver samples, which implies that this synthetic thiol-containing antioxidant is capable of abrogating lead-induced oxidative stress in vivo. Overall, these results suggest that lead-induced oxidative stress in vivo can be mitigated by pharmacologic interventions, which encompass both chelating as well as thiol-mediated antioxidant functions.

168 citations