Hydrogen produced in rat colon improves in vivo redox balance due to induced regeneration of α-tocopherol.

We investigated whether non-digestible saccharide fermentation-derived hydrogen molecules (H2) in rat colon could improve the in vivo reduction-oxidation balance via regeneration of α-tocopherol, by assessing their effect on hydroxyl radicals, the α-tocopherol concentration and the reduction-oxidation balance. In experiment 1, a Fenton reaction with phenylalanine (0 or 1.37 mmol/L of H2) was conducted. In experiment 2, rats received intraperitoneally 400 mg/kg of corn oil containing phorone, 7 days after drinking ad libitum water containing 0 or 4% fructooligosaccharides (groups CP and FP, respectively). In experiment 3, rats unable to synthesise ascorbic acid, drank ad libitum for 14 days, water with 240 mg/L (group AC), 20 mg of ascorbic acid/L (group DC) or 20 mg of ascorbic acid/L and 4% fructooligosaccharides (group DCF). In the Fenton reaction, H2 reduced tyrosine produced from phenylalanine to 72% when platinum was added and to 92% when platinum was excluded. In experiment 2, liver glutathione was depleted by administration of phorone to rats. However, compared with CP, no change in the m-tyrosine concentration in the liver of FP was detected. In experiment 3, net H2 excretion was higher in DCF than in the other rats, 3 days after the experiment ended. Furthermore, the concentrations of H2 and α-tocopherol and the reduction-oxidation glutathione ratio in perirenal adipose tissue of rats were significantly higher and lower, respectively, in DCF than in DC. To summarise, in rat colon, fermentation-derived H2 further reduced the reduction-oxidation balance in perirenal adipose tissue through increased regeneration of α-tocopherol.