Buthionine-[S,R]-sulfoximine (BSO) and auranofin (AUR) affected glutathione and thioredoxin metabolism.

<p>A: NADPH is a source of reducing equivalents for the glutathione system consisting of reduced glutathione (GSH), glutathione disulfide (GSSG), glutathione peroxidase (GPx), and glutathione reductase (GR) and the thioredoxin system consisting of reduced thioredoxin [Trx(SH)₂], thioredoxin disulfide [Trx(S₂)], peroxiredoxin (Prx), and thioredoxin reductase (TR). BSO inhibits γ-glutamylcysteine ligase (GCL), which catalyzes the reaction between cysteine and L-glutamate to form γ-glutamyl-cysteine. Glutathione synthetase (GS) converts γ-GCS into GSH. AUR inhibits TR activity. FaDu, Cal-27 and SCC-25 cells were treated with 0.5 µM AUR and/or 1 mM BSO for 24 h and analyzed for total GSH (B) and TR activity (C). Error bars represent the standard error of the mean (SEM) of N = 3 experiments *, p<0.05 versus control.