, 2009). Iron is capable of stimulating see more free radical formation,

increased protein and DNA oxidation in the Alzheimer‘s brain, enhanced lipid peroxidation, decreased level of cytochrome c oxidase and advanced glycation end products, carbonyls, malondialdehyde (MDA), peroxynitrite and HO-1 (Dröge, 2002). Excess of iron in brain tissue may activate the iron-dependent HIF-1 prolyl-4-hydroxylase, resulting in the proteasomal-mediated degradation of HIF. Iron-chelating drugs have been shown to stabilize HIF-1, which, in turn, would transactivate the expression of established protective genes, including vascular endothelial growth factor (VEGF), erythropoietin, aldolase and p21. In conclusion, considering the multiple iron-operating sites in Alzheimer’s disease, iron chelators, possessing several active neuroprotective moieties

can suppress the wide spectrum of oxidative stress-associated neuropathologies, as well as amyloid precursor protein (APP) translation, Aβ generation, and amyloid plaque and neurofibrillary tangle (NFT) formation (Amit et al., 2008). Rheumatoid arthritis is another find more disorder linked with the effect of ROS (Dröge, 2002). This disorder is characterized by an overall low level of body iron (anemia), however elevated iron is found in the synovial fluid of arthritic joints (Gutteridge, 1987). This suggests a marked disorder in iron metabolism and points to a mechanism in which elevated superoxide radical liberates free (catalytic) iron from ferritin in synovial fluid catalysing thus the formation of damaging hydroxyl radicals via the Fenton reaction. Some studies evidenced that effective iron chelators can improve symptoms of rheumatoid arthritis. The most oxidation numbers

of copper in living organisms are Cu(II) and Cu(I). The essential trace element copper is a cofactor of many enzymes involved in redox reactions, such as cytochrome c oxidase, ascorbate oxidase, or superoxide dismutase. In addition to its enzymatic roles, copper is used in biological systems for electron transport (Valko et al., 2005). The blue copper proteins that participate in electron transport include Protein kinase N1 azurin and plastocyanin. Copper is readily absorbed from the diet across the small intestine (∼2 mg/day) and stored in the liver. The major excretory route of copper stored in liver is via the biliary pathway (∼80%) (Linder and Hazegh-Azam, 1996). Copper is bound to either serum albumin or histidine and trafficked through the bloodstream for delivery to tissues or storage in the liver. Copper is imported into the hepatocytes via the high-affinity human copper transporter, hCtr1 (Zhou and Gitschier, 1997), localized on the plasma membrane. hCtr1 also participates in the intracellular compartmentalization of this metal.