, 2010 and Marin et al., 2011). The mechanism by which the antioxidant astaxanthin improves phagocytic capacity of neutrophils remains to be elucidated in future studies. Although it is well known that phagocytosis in neutrophil cells is a process which involves intracellular calcium mobilization, in the present study we did not observe any changes in intracellular calcium concentration among all groups. By means of Maillard reaction, MGO is able to cross-link with cellular proteins on targeted amino acids (arginine,

lysine), leading to the formation of advanced glycation end-products (AGEs), and thus contributing to aging and complications in chronic GSK-3 cancer diseases (Fleming et al., 2011 and Thornalley, 2005). Similarly to our results, some authors showed which MGO inactivate the enzyme glutathione reductase (Paget et al., 1998, Park et al., 2003 and Wu and Juurlink, LY2835219 solubility dmso 2002). Glutathione reductase recycles GSSG using NADPH

as a cofactor, reestablishing the intracellular content of reduced glutathione (GSH) (Juurlink, 1999 and Wu and Juurlink, 2002). Other studies have shown that MGO reduced GSH content making cells more sensitive to oxidative stress (Kikuchi et al., 1999, Meister, 1988 and Shinpo et al., 2000). The inactivation of MGO is a process catalyzed by the glyoxalase system that uses glutathione (GSH) as a cofactor. MGO inactivated bovine glutathione peroxidase in a time and dose-dependent manner, forming a connection with glutathione to sites of arginine 184 and 185 (Park et al., 2003). High concentration of MGO in plasma and aorta are associated with increased levels of superoxide, significantly reduced levels of GSH, decreased activity of glutathione peroxidase

and glutathione reductase in SHR MRIP rats with high blood pressure (Wang et al., 2005). Contrasting with these studies, we did not observe any change in the content of GSH, GSSG and in the rate GSH/GSSG (Table 2). Studies by Chang and colleagues (Chang et al., 2005) demonstrated that MGO caused mitochondrial oxidative stress by increasing the mitochondrial production of superoxide, nitric oxide and peroxynitrite. MGO can inhibit complex III and thereby disrupt the electron transport chain, leading to leakage of electrons to form superoxide anion (Wang et al., 2009). The direct effect of MGO on mitochondria was investigated by Desai and colleagues (Desai and Wu, 2007) using MitoSOX, a mitochondrial specific probe used to detect mitochondrial superoxide production. Incubation of vessel smooth muscle cells with MGO 30 μmol/L significantly induced mitochondrial superoxide production as compared with the group of untreated cells.