Acute oxidative stress induced by ischemia-reperfusion or inflammation causes serious damage to tissues, and persistent oxidative stress is accepted as one of the causes of many common diseases including cancer. We show here that hydrogen (H(2)) has potential as an antioxidant in preventive and therapeutic applications. We induced acute oxidative stress in cultured cells by three independent methods. H(2) selectively reduced the hydroxyl radical, the most cytotoxic of reactive oxygen species (ROS), and effectively protected cells; however, H(2) did not react with other ROS, which possess physiological roles. We used an acute rat model in which oxidative stress damage was induced in the brain by focal ischemia and reperfusion. The inhalation of H(2) gas markedly suppressed brain injury by buffering the effects of oxidative stress. Thus H(2) can be used as an effective antioxidant therapy; owing to its ability to rapidly diffuse across membranes, it can reach and react with cytotoxic ROS and thus protect against oxidative damage.
The analysis using the DBNBS reduction method and the DCFH-DA intracellular reactive oxygen species (ROS) determination method revealed that ERW and diseases-improvable natural waters such as Nordenau water in Germany and Hita water in Japan were all reduced waters (RWs) which could function as active hydrogen donors and intracellular ROS scavengers. RWs suppressed the activity of protein tyrosine phosphatase (PTP), which inactivates insulin receptor, suggesting their anti-type 2 diabetes effects via redox regulation. The clinical test of 356 diabetes patients drinking Nordenau water in Germany resulted in the improvement of the relevant tests parameters after 6 days, suggesting the correlation of these changes with the fluctuation of ROS levels in their blood.
Oxidative stress is produced under diabetic conditions and involved in progression of pancreatic beta-cell dysfunction. Both an increase in reactive oxygen free radical species (ROS) and a decrease in the antioxidant defense mechanism lead to the increase in oxidative stress in diabetes. Electrolyzed reduced water (ERW) with ROS scavenging ability may have a potential effect on diabetic animals, a model for high oxidative stress. Therefore, the present study examined the possible anti-diabetic effect of ERW in genetically diabetic mouse strain C57BL/6J-db/db (db/db). ERW with ROS scavenging ability reduced the blood glucose concentration, increased blood insulin level, improved glucose tolerance and preserved beta-cell mass in db/db mice. The present data suggest that ERW may protects beta-cell damage and would be useful for antidiabetic agent.
Electrolyzed water (EW) generated on the cathode side reportedly displays anti-oxidative properties, and application of EW to hemodialysis (HD) systems supposedly suppresses oxidative markers in patients on HD. However, most of the chemical properties and biological effects of such solutions remain unclear. This study aimed to examine those issues to clarify the scientific background for the clinical use of EW solution. Reverse osmosis water comprising EW from the cathode side (e-RO) was prepared and used to process a test HD solution (e-HD). Chemical and biological properties of these solutions were compared with controls. Redox properties were examined by chemiluminescence (CL) of the luminol-H(2)O(2) system. Biological effects of e-RO on human polymorphonuclear leukocytes (PMNs) were tested with respect to the cellular protection against methylglyoxal, and with respect to the preservation of cellular function as to radical generation. Control HD solution presented the highest CL, followed by e-HD, control RO, suggesting a lower oxidative capacity for EW-based solutions. Increased levels of dissolved hydrogen were characteristic of e-RO and e-HD. Application of e-RO tended to be associated with less injury of PMNs by methylglyoxal, and with significantly higher levels of radical generation compared with the control. Compared with control HD, e-RO-based HD solution displays less-oxidative capacity in chemical terms, and may at least partly facilitate preservation of PMN viability. These results appear to offer a scientific basis for supporting the clinical challenge of applying this technology to HD treatment.
We have recently showed that molecular hydrogen has great potential for selectively reducing cytotoxic reactive oxygen species, such as hydroxyl radicals, and that inhalation of hydrogen gas decreases cerebral infarction volume by reducing oxidative stress [I. Ohsawa, M. Ishikawa, K. Takahashi, M. Watanabe, K. Nishimaki, K. Yamagata, K.-I. Katsura, Y. Katayama, S. Asoh, S. Ohta, Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals, Nat. Med., 13 (2007) 688-694]. Here we show that the inhalation of hydrogen gas is applicable for hepatic injury caused by ischemia/reperfusion, using mice. The portal triad to the left lobe and the left middle lobe of the liver were completely occluded for 90min, followed by reperfusion for 180min. Inhalation of hydrogen gas (1-4%) during the last 190min suppressed hepatic cell death, and reduced levels of serum alanine aminotransferase and hepatic malondialdehyde. In contrast, helium gas showed no protective effect, suggesting that the protective effect by hydrogen gas is specific. Thus, we propose that inhalation of hydrogen gas is a widely applicable method to reduce oxidative stress.