Scheme of the different reactions that take place in the mitochondria to cope with the oxidative stress derived from the presence of superoxide anion, hydrogen peroxide, and hydroxyl radical. A, Removal of H2O2, and B, elimination of hydroxyl radical generated through the Fenton reaction. GSH peroxidase (Gpx), GSSG-reductase (GR); GSSG, glutaredoxin (Grx), Mn-dependent superoxide dismutase (MnSOD), thioredoxin-2 (Trx2), Trx-Reductase (TrxR), peroxiredoxin III (PrxIII).