The protective role of hydrogen-rich saline in experimental liver injury in mice

Background & Aims: Reactive oxygen species (ROS) are considered to play a prominent causative role in the development of various hepatic disorders. Antioxidants have been effectively demonstrated to protect against hepatic damage. Hydrogen (H-2), a new antioxidant, was reported to selectively reduce the strongest oxidants, such as hydroxyl radicals ((OH)-O-center dot) and peroxynitrite (ONOO-), without disturbing metabolic oxidation-reduction reactions or disrupting ROS involved in cell signaling. In place of H-2 gas, hydrogen-rich saline (HS) may be more suitable for clinical application. We herein aim to verify its protective effects in experimental models of liver injury. Methods: H-2 concentration in vivo was detected by hydrogen microelectrode for the first time. Liver damage, ROS accumulation, cytokine levels, and apoptotic protein expression were, respectively, evaluated after GalN/LPS, CCl4, and DEN challenge. Simultaneously, CCl4-induced hepatic cirrhosis and DEN-induced hepatocyte proliferation were measured. Results: HS significantly increased hydrogen concentration in liver and kidney tissues. As a result, acute liver injury, hepatic cirrhosis, and hepatocyte proliferation were reduced through the quenching of detrimental ROS. Activity of pro-apoptotic players, such as JNK and caspase-3, were also inhibited. Conclusions: HS could protect against liver injury and also inhibit the processes leading to liver cirrhosis and hepatocyte compensatory proliferation. (c) 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.