Glutathione (a-glutamyl-cysteinyl-glycine; GSH) is the most abundant low-molecular-weight thiol found in both prokaryotic and eukaryotic organisms. GSH has potent electron-donating capacity that renders GSH both a potent antioxidant and a conventional cofactor for enzymatic reactions. GSH participates in many cellular functions such as redox control, stress defense, drug detoxification and cell signaling including regulation of DNA and protein synthesis, gene expression, apoptosis and cell proliferation. GSH concentration in the cell is homeostatically controlled, being continually...