Oral glutathione increases tissue glutathione in vivo.

Mice were given an oral dose of glutathione (GSH) (100 mg/kg) and concentrations of GSH were measured at 30, 45 and 60 min in blood plasma and after 1 h in liver, kidney, heart, lung, brain, small intestine and skin. In control mice, GSH concentrations in plasma increased from 30 microM to 75 microM within 30 min of oral GSH administration, consistent with a rapid flux of GSH from the intestinal lumen to plasma. Under these GSH-sufficient conditions, no increases over control values were obtained in GSH concentrations in most tissues except lung over the same time course.

Fate of dietary glutathione: disposition in the gastrointestinal tract.

Studies were performed in rats that had been fasted 24 h, fed a glutathione (GSH)-free semisynthetic diet (AIN-76), and fed the same diet supplemented with GSH. The results from the fasted rats and those fed GSH-free diet showed that the duodenum and jejunum contained 0.2-0.

Bioavailability of dietary glutathione: effect on plasma concentration.

Plasma glutathione (GSH) concentration in rats increased from approximately 15 to 30 microM after administration of GSH either as a liquid bolus (30 mumol) or mixed (2.5-50 mg/g) in AIN-76 semisynthetic diet. GSH concentration was maximal at 90-120 min after GSH administration and remained high for over 3 h.