Contents lists available at ScienceDirect Toxicology and Applied Pharmacology journal homepage: www.elsevier.com/locate/taap Iron chelation by deferasirox confers protection against concanavalin A- induced liver fibrosis: A mechanistic approach Nada Adel, Eman M. Mantawy, Doaa A. El-Sherbiny, Ebtehal El-Demerdash ⁎ Department of Pharmacology & Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt ARTICLE INFO Keywords: Liver fibrosis Iron overload Concanavalin A Deferasirox Hepcidin ABSTRACT Hepatic iron overload is one of the causative factors for chronic liver injury and fibrosis. The present study aimed to investigate the potential antifibrotic effect of the iron chelator; deferasirox (DFX) in experimentally-induced liver fibrosis in rats. Male Sprague-Dawley rats were administered concanavalin A (Con A) and/or DFX for 6 consecutive weeks. Con A injection induced significant hepatotoxicity as was evident by the elevated transa- minases activity, and decreased albumin level. Also, it disturbed the iron homeostasis through increasing C/EBP homologous protein (CHOP), decreasing phosphorylated cAMP responsive element binding protein(P-CREB) and hepcidin levels leading to significant serum and hepatic iron overload. In addition, it induced an imbalance in the oxidative status of the liver via upregulating NADPH oxidase 4 (NOX4), together with a marked decrease in anti-oxidant enzymes' activities. As a consequence, upregulation of nuclear factor-kappa b (NF-κB) and the downstream inflammatory mediators was observed. Those events all together precipitated in initiation of liver fibrosis as confirmed by the elevation of alpha-smooth muscle actin (α-SMA) and liver collagen content. Co- treatment with DFX protected against experimentally-induced liver fibrosis in rats via its iron chelating, anti- oxidant, and anti-inflammatory properties. These findings imply that DFX can attenuate the progression of liver fibrosis. 1. Introduction Liver fibrosis and its end-stage, cirrhosis, represent the final common pathway of virtually all chronic liver diseases (Rockey, 2008). Liver fibrosis is a wound healing process characterized by the excessive deposition of extracellular matrix (ECM) proteins (Bataller and Brenner, 2005). The pivotal hepatic cell population responsible for ECM pro- duction is hepatic stellate cells (HSCs) (Hernandez-Gea and Friedman, 2011). Among the multiple pathogenic features in the fibrogenesis process, hepatic iron overload was observed in patients chronically infected with HCV, and it correlated with the progression of the disease to cir- rhosis and HCC (Isom et al., 2009). Additionally, patients with iron overload diseases as thalassemia and patients receiving numerous blood transfusions often present with hepatic fibrosis (Kew, 2014). Iron overload causes tissue damage via production of tremendous amount of free radicals (Galaris and Pantopoulos, 2008). Those free radicals target important cellular structures, ultimately leading to hepatic lipid per- oxidation, oxidation of amino acids, protein fragmentation, and DNA damage (Dalle-Donne et al., 2006). Oxidative damage to different liver organelles triggers a focal inflammatory reaction and induces the re- lease of cytokines from activated kupffer cells (Jaeschke, 2011). Re- leased cytokines further activate HSCs stimulating them to produce ECM (Elsharkawy and Mann, 2007). In this context, both oxidative stress and inflammatory signaling pathways are considered the main culprit triggering factors for activation of HSCs, and hence pathogenesis of liver fibrosis (Poli, 2000). Being a dynamic process, fibrosis can be reversed, and normal he- patic architecture and function can be restored (Povero et al., 2010). In this regard, iron reduction by phlebotomy or a low-iron diet has been shown to improve serum aminotransferases in patients with hepatitis C (Hayashi et al., 1994). Consequently, iron chelators represent pro- mising candidates for halting the progression of liver fibrosis (Kalinowski and Richardson, 2005). In our lab, deferoxamine has been https://doi.org/10.1016/j.taap.2019.114748 Received 13 July 2019; Received in revised form 4 September 2019; Accepted 5 September 2019 Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; CAT, catalase; Con A, concanavalin A; CHOP, C/EBP homologous protein; DFX, deferasirox; ECM, extracellular matrix; HCV, hepatitis C virus; HSCs, hepatic stellate cells; IFN-γ, interferon gamma; iNOS, inducible nitric oxide synthase; MDA, malondialdehyde; NOX-4, NADPH oxidase-4; NF-κB, nuclear factor kappa B; P-CREB, phosphorylated cAMP responsive element binding protein; α-SMA, alpha- smooth muscle actin; TIBC, total iron binding capacity; TNF-α, tumor necrosis factor alpha; TSAT, transferrin saturation. ⁎ Corresponding author at: Pharmacology & Toxicology Department, Faculty of Pharmacy, Ain Shams University, Abbasia, Cairo, Egypt. E-mail address: ebtehal_dm@pharma.asu.edu.eg (E. El-Demerdash). Toxicology and Applied Pharmacology 382 (2019) 114748 Available online 06 September 2019 0041-008X/ © 2019 Published by Elsevier Inc. T