The displaced redox metal can then leave the cell, reducing thus its ability to catalyze decomposition

of Fenton reaction (hydroxyl radical formation). An example of the zinc antagonism mechanism is documented by iron-mediated xanthine/xanthine oxidase-induced peroxidation of erythrocyte membranes. Antagonism of radical formation by zinc was reported in copper–iron ascorbate-induced DNA strand breaks, superoxide and hydroxyl radical from xanthine oxidase and NADPH oxidase, Fe(III)-ascorbate-induced methemoglobin formation in red blood cells and other systems. Zinc deficiency has been associated with increased levels of oxidative damage including increased lipid, protein and DNA oxidation (Prasad, 2009). Animal studies confirmed that chronic or long-term absence of zinc makes an organism more to oxidative stress-induced Selleck ABT199 injury. Zinc deficiency effects, combined with ROS formation has been documented by carbon centered free radical production and lipid peroxidation in lung damage, formation of conjugated dienes and malondialdehyde in liver microsomes and lipoprotein oxidation and galactosamine-induced hepatitis in rats (reviewed in Valko et al., 2005). The metallothioneins are metal-binding proteins (6000–7000 kDa) containing 60–68 amino acid residues. The beneficial effects of long-term administration of zinc can be linked to the induction of some other species that serves as the ultimate

antioxidants, among which one of the most effective seems to be metallothioneins (Powell, 2000). About 25–30% of all aminoacids in metallothioneins are cysteine, Selleck Volasertib containing no aromatic amino acids or disulphide bonds and therefore can effectively bind 5–7 g zinc (mol/protein). Recent

studies have reported that ifenprodil the metallothioneins represent a connection between cellular zinc and the redox state of the cell (Maret, 2008). Under conditions of high oxidative stress, changes in the cellular redox state result in release of zinc from metallothionein as a result of sulphide/disulphide exchange. Zinc as an antioxidant, reduces formation of free radicals by several ways (Prasad, 2009) (Fig. 5). Zinc acts as an inhibitor of NADPH oxidase, inducer of metallothionein (effective scavenger of radicals) and is an integral metal of Cu, Zn-SOD. ROS are known to activate NF-kappaB which in turn activates growth factors, antiapoptotic molecules resulting in cell proliferation (cancer), inflammatory cytokines and adhesion molecules (Prasad, 2009). Zinc reduces inflammatory cytokine production by upregulation of a zinc-finger protein, A20, which inhibits NF-kB activation via TRAF pathway (Prasad, 2008). Thus zinc functions not only as an antioxidant but also as an anti-inflammatory agent. A beneficial effect of intake of the zinc on oxidative stress markers in elderly people has been reported (Prasad et al., 2007). Interleukin (IL-2) is a molecule of cytokine immune system responding to microbial infection.