Molecular hydrogen as a new selective anti-oxidation therapeutic medical gas for clinical research

Hydrogen (H₂) is a colorless, odorless gas that can act as a reducing agent under certain circumstances. Previously considered physiologically an inert and nonfunctional molecule in mammalian cells, H₂ largely went ignored until Nature Medicine revealed the antioxidant and cytoprotective effects of hydrogen gas in a focal stroke model. Reactive oxygen species (ROS）is generated inside the body throughout our daily lives as a by-product of the energy metabolism by oxidative phosphorylation, which can cause biofilm system damage and intracellular oxidative phosphorylation disorders. H₂ reacts with highly reactive oxidants such as hydroxyl radical (·OH) and peroxynitrite (ONOO^-) inside cells to improve ischemia reperfusion injury. In addition, hydrogen is a potent antiapoptotic and anti-inflammatory agent and can be used for potential medical applications in cells, tissues and organs. As a new antioxidant, hydrogen has the advantages of non-toxicity, easy diffusion and selective neutralization. This review makes a case for supporting hydrogen as a new antioxidant medicine for clinical applications. We also hope to provide a reference for the further study of hydrogen to preserve blood cells in transfusion medicine.