Iron chelator deferasirox rescued mice from Fas-induced fulminant hepatitis

Fulminant hepatitis is a disease characterized by development of hepatic failure due to severe liver cell injury. Orthotopic liver transplantation is the therapy proven to improve patient survival; however, less burdensome and safer strategies are required. In a previous study, we showed that iron was intimately involved in hepatocyte apoptosis by demonstrating that spontaneous development of fulminant hepatitis in Long-Evans cinnamon rats was prevented by feeding an iron-deficient diet. Recently, a new iron chelator, deferasirox, has become widely available for the treatment of transfusional hemosiderosis. Deferasirox demonstrated good efficacy and improved compliance due to convenient, once-daily p.o. administration. Our aim was to investigate the efficacy of deferasirox as a therapeutic drug against fulminant hepatitis.

Human primary hepatocytes undergoing Fas-stimulated apoptosis were challenged with deferoxamine (DFO) in vitro. In further in vivo experiments, we tested DFO in a mice model of fulminant hepatitis induced by Fas-stimulation.

The apoptosis-inducing activity of anti-Fas antibody on human primary hepatocytes was inhibited by the chelation of iron with DFO. DFO suppressed the Fas-induced production of reactive oxygen species (ROS) and the activation of caspase-3, both of which were also suppressed by antioxidant, N-acetyl-L-cystein. In the in vivo experiments, deferasirox effectively reduced hepatic iron concentrations and rescued mice from Fas-induced fulminant hepatitis.

These findings indicated that the iron chelation exerted a hepatoprotective effect by scavenging ROS upstream of caspase-3 and that iron chelation with deferasirox is a potential treatment for patients with fulminant hepatitis.