Study: Oral Glutathione  Bioavailable

NEW YORK CITYAn oral dose of glutathione increased blood, tissue and extracellular glutathione levels, and the absorption of glutathione was dependent on the cystic fibrosis transmembrane conductance regulator, according to a new study that used Setria® Glutathione from Kyowa Hakko USA. Brian J. Day, Ph.D., vice chair of Research and the Department of Medicine Professor at National Jewish Health, examined whether oral glutathione (GSH) or glutathione disulfide (GSSG) treatment could increase lung epithelial lining fluid (ELF) GSH levels, and whether the cystic fibrosis transmembrane conductance regulator (CFTR) plays a role in this process.

"Many lung diseases are associated with low glutathione levels, including cystic fibrosis, chronic obstructive pulmonary disease and acute respiratory distress syndrome," Day noted. Day will present his paper, "Elevation of Glutathione Levels in the Lung by Oral Glutathione Administration in Mice," at the 51st annual meeting of the American College of Nutrition on Saturday, Oct. 9.

Setria Glutathione is a tripeptide of three amino acids and found in every cell in the body. Glutathione fights free-radical damage, helps to support the liver so it can detoxify the body, as well as promotes a healthy immune system.

In the study, the pharmacokinetic profile of an oral bolus dose of GSH (300 mg/kg) was determined in mice. Plasma, ELF, bronchoalveolar lavage (BAL) cells and lung tissue were then analyzed for GSH content. Day found a rapid elevation in the GSH levels that peaked at 30 minutes in the plasma and 60 minutes in the lung, ELF and BAL cells after oral GSH dosing. Oral GSH treatment produced a selective increase in the reduced and active form of GSH in all lung compartments examined. The oral GSSG treatment (also 300mg/kg) resulted in a smaller increase of GSH levels.

To evaluate the role of CFTR in this process, Cftr KO mice and gut corrected Cftr KO-Tg mice were given an oral bolus dose of GSH (300 mg/kg) and compared to wild type mice for changes in GSH levels in plasma, lung, ELF and BAL cells. There was a two-fold increase in plasma, a two-fold increase in lung, a five-fold increase in ELF, and a three- fold increase in BAL cell GSH levels at 60 minutes in wild type mice, however GSH levels only increased by 40 percent in the plasma, 60 percent in the lung, 50 percent in the ELF, and two-fold in the BAL cells within the gut corrected Cftr KO-Tg mice.  No change in GSH levels was observed in the uncorrected Cftr KO mice.

Kyowa Hakko is an international health-ingredients manufacturer and also manufactures and markets pharmaceuticals, nutraceuticals and food products. Kyowa is the maker of branded ingredients including Cognizin® Citicoline, Hydrafend Hyaluronic Acid, Lumistor® L-Hydroxyproline, Setria® Glutathione, Pantein® Pantothenic Acid, Kyowa CoQ10 as well as Sustamine L-Alanyl-L-Glutamine.