molecules Review A Review on Coordination Properties of Thiol-Containing Chelating Agents Towards Mercury, Cadmium, and Lead Geir Bjørklund 1,* , Guido Crisponi 2 , Valeria Marina Nurchi 3 , Rosita Cappai 3, Aleksandra Buha Djordjevic 4 and Jan Aaseth 5,6,7,* 1 Council for Nutritional and Environmental Medicine, N-8610 Mo i Rana, Norway 2 Cittadella Universitaria, University of Cagliari, 09042 Cagliari, Italy 3 Department of Life and Environmental Sciences, University of Cagliari, 09042 Cagliari, Italy 4 Department of Toxicology “Akademik Danilo Soldatovi´c”,Faculty of Pharmacy, University of Belgrade, 11000 Belgrade, Serbia 5 Research Department, Innlandet Hospital, N-2380 Brumunddal, Norway 6 Inland Norway University of Applied Sciences, N-2411 Elverum, Norway 7 IM Sechenov First Moscow State Medical University (Sechenov University), 119146 Moscow, Russia * Correspondence:
[email protected] (G.B.);
[email protected] (J.A.) Academic Editor: Erika Ferrari Received: 24 July 2019; Accepted: 31 August 2019; Published: 6 September 2019 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.