Natural reduced water suppressed anxiety and protected the heightened oxidative stress in rats

Koji Masuda, Yoshihiro Tanaka, Masayuki Kanehisa, Taiga Ninomiya, Ayako Inoue, Haruka Higuma, Chiwa Kawashima, Mari Nakanishi, Kana Okamoto, Jotaro Akiyoshi Department of Neuropsychiatry, Oita University Faculty of Medicine, Hasama-Machi, Oita, Japan Background: In Japan, the effects of reduced water, such as hydrogen-rich electrolyzed reduced water and natural reduced water, like Hita Tenryosui water®, have been examined. The purpose of the present study was to identify the role of natural reduced water in anxiety and blood biochemical analysis.Materials and methods: Natural reduced water and distilled water were administered to rats for 180 consecutive days, and their effect on anxiety-like behavior and depression was examined by using elevated plus maze, light/dark, forced swimming, and conditioned fear tests. Before and after administration of natural reduced or distilled water, we performed blood and urine analyses.Results: Natural reduced water exhibited anxiolytic-like effects in the conditioned fear and elevated plus maze tests. The mean levels of urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) in the natural reduced water were significantly lower than the distilled water group. Natural reduced water group also showed decrease in blood–urea nitrogen levels compared with the distilled water group.Conclusion: These results indicate that natural reduced water may decrease anxiety-related behaviors and prevent heightened oxidative stress. Keywords: urea nitrogen, depression, Hita Tenryosui, conditioned fear, elevated plus maze, 8-OHdG