Contents lists available at ScienceDirect Toxicology in Vitro journal homepage: www.elsevier.com/locate/toxinvit Protective effects of isatin and its synthetic derivatives against iron, copper and lead toxicity Hamid Moghimi Benhangi a , Sheida Ahmadi b , Mohammad Hakimi b , Azam Molafilabi c , Habibollah Faraji d , Baratali Mashkani e,f, ⁎ a Department of Medical Toxicology, Islamic Azad University, Shahreza, Iran b Department of Chemistry, Payame Noor University, Tehran 19395-4697, Iran c Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran d Department of Laboratory Sciences, Faculty of Para-Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran e Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran f Department of Clinical Biochemistry, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran ARTICLE INFO Keywords: Isatin Derivatives Cytotoxicity HEK293 Copper Iron Lead ABSTRACT Introduction: While some metals are required for physiological functions in the form of essential trace elements, they can cause toxicity in the excessive concentrations. Chelation therapy was used to reduce the adverse effects of acute and chronic poisoning by metals. Isatin derivatives form complexes with copper ions indicating that they may have protective activity against metal overload. Method: In this study, four compounds (isatin and three isatin-derivatives Mj1, TR and Mk1) were evaluated for drug-likeliness. Then their potency inhibiting cell proliferation was determined in HEK293 cell culture assay. Finally, IC 50 values for lead, copper, and iron was evaluated in the absence and also the presence of isatin and its derivatives. Results: Isatin and its derivatives used in this study complied with the Lipinski criteria for drug-likeliness. The greatest difference between the IC 50 values and the non-toxic dose was obtained for TR and Mj1, respectively. Pretreatment with the Mj1 increased the IC 50 values for lead, iron, and copper, by 2.1, 1.7 and 1.7 times, respectively. At non-toxic dose, TR has only increased the IC 50 values for lead and copper by 1.4 and 1.3 times without affecting iron cytotoxicity. Mk1 increased the IC 50 values for lead, copper, and iron by 1.3, 1.8 and 1.7 times, respectively. Conclusions: Mj1 is suggested as a lead compound for developing therapeutic agents for lead (Pb) toxicity and Mk1 for copper and iron. 1. Introduction Some metals are essential trace elements for proper function of the biological systems. However, excessive intake of metal ions can perturb various biochemical and physiological functions in living organisms (Waalkes et al., 2004). Metal toxicity increases oxidative stress; which causes DNA mutation (Kasprzak, 2002), lipid peroxidation, and protein denaturation and may have a role in the carcinogenicity of metals (Waisberg et al., 2003; Valko et al., 2006). Small quantities of iron and copper are essential for hematopoiesis and other physiologic processes (Collins et al., 2010). However, iron excess leads to ischemic heart disease, arthrosclerosis, suppression of antitumor actions of macrophages and facilitation of cancer growth (Alpert, 2004; Grazuleviciene et al., 2009; Gujja et al., 2010). Additionally, several neurodegenerative abnormalities are associated with inappropriate metabolism of iron in the brain, such as neuro- ferritinopathy and aceruloplasminemia (Papanikolaou & Pantopoulos, 2005). Large amounts of copper intake cause hepatic necrosis and sometimes death (Stern, 2010). Unlike iron and copper, lead is a highly toxic metal without any known biological functions. It disrupts various metabolic pathways by substituting other bivalent cations in the cell causing cell malfunctions and interfere in the intra- and inter-cellular signaling, protein folding, apoptosis, enzyme regulation, the release of neurotransmitters and other important procecces (Lawson et al., 2016). Chelating agents can bind metal ions and remove them from in- tracellular or extracellular spaces (Bouvard et al., 2009). 2, 3-Di- mercaprol has been used for many years for lead and arsenic chelation (Flora & Pachauri, 2010). Desferoxamine (DFO) is an intracellular iron https://doi.org/10.1016/j.tiv.2018.10.004 Received 25 May 2018; Received in revised form 27 September 2018; Accepted 2 October 2018 ⁎ Corresponding author at: Surgical Oncology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran E-mail address: mashkaniba@mums.ac.ir (B. Mashkani). Toxicology in Vitro 54 (2019) 232–236 Available online 05 October 2018 0887-2333/ © 2018 Elsevier Ltd. All rights reserved. T