FIG. 1.

The schematic of the glutathione system. GSH is synthesized from amino acids by the action of γ-glutamylcysteine synthetase and glutamyl synthase. GSH undergoes the GSH-PX coupled reaction, thereby detoxifying ROS such as H₂O₂. During this reaction, GSH is oxidized and generates GSSG, which is recycled back to GSH by the action of GR at the expense of reduced nicotinamide (NADPH/H⁺), thus forming the redox cycle. GSH, glutathione; GSH-PX, glutathione-peroxidase; GR, glutathione reductase; H₂O₂, hydrogen peroxide; ROS, reactive oxygen species. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars