Title:Protective Effects of Hydrogen against Irradiation
Volume: 27
Issue: 5
Author(s): Yasuhiro Terasaki*, Mika Terasaki and Akira Shimizu
Affiliation:
- Department of Analytic Human Pathology, Nippon Medical School, Tokyo,Japan
Keywords:
Apoptosis, reactive oxygen species, hydroxyl radical, peroxynitrite, free radical scavengers, radioprotective.
Abstract: Radiation-induced lung injury is characterized by an acute pneumonia phase followed by a fibrotic
phase. At the time of irradiation, a rapid, short-lived burst of reactive oxygen species (ROS) such as hydroxyl
radicals (•OH) occurs, but chronic radiation-induced lung injury may occur due to excess ROS such as H2O2,
O2•−, ONOO−, and •OH. Molecular hydrogen (H2) is an efficient antioxidant that quickly diffuses cell membranes,
reduces ROS such as •OH and ONOO−, and suppresses damage caused by oxidative stress in various
organs. In 2011, through the evaluation of electron-spin resonance and fluorescent indicator signals, we had reported
that H2 can eliminate •OH and can protect against oxidative stress-related apoptotic damage induced by
irradiation of cultured lung epithelial cells. We had explored for the first time the radioprotective effects of H2
treatment on acute and chronic radiation-induced lung damage in mice by inhaled H2 gas (for acute) and imbibed
H2-enriched water (for chronic). Thus, we had proposed that H2 be considered a potential radioprotective
agent. Recent publications have shown that H2 directly neutralizes highly reactive oxidants and indirectly reduces
oxidative stress by regulating the expression of various genes. By regulating gene expression, H2 functions
as an anti-inflammatory and anti-apoptotic molecule and promotes energy metabolism. The increased evidence
obtained from cultured cells or animal experiments reveal a putative place for H2 treatment and its radioprotective
effect clinically. This review focuses on major scientific advances in the treatment of H2 as a new
class of radioprotective agents.
