Curr Pharm Des 12:4601–4611PubMedCrossRef”
“Introduction Reactive oxygen species (ROS) such as O2 −, H2O2 and •OH are generated in cells through aerobic metabolic processes or as a result of interaction with exogenous agents. Low levels are essential for proper cell function, but excess

levels of ROS are responsible for ‘oxidative stress’ which has been linked with the progression of ageing and many human diseases, e.g. neurogenerative, cardiovascular VX-809 order and cancer. Superoxide dismutases (SODs), catalase (CAT) and glutathione peroxidase (GPx) are enzymes which act as a primary cellular defence system against oxidative damage in living organisms. Copper(II) has an important biological role in all living systems as an essential trace element (Linder and Hazegh-Azam, 1996). The Cu(II) complexes with organic ligands have been used as analgesic, antipyretic, antiinflammatory and a platelet anti-aggregating agents. Due to the redox behaviour of the Cu(II)/Cu(I) system and the interaction of copper complexes with O2 biomimetic complexes

of copper ions with biologically interesting ligand have been investigated in detail. They have antioxidant, antitumor activity and protect against some injuries being consequences of UV exposure (Zheng et al., 2006). Recently, several reports have appeared in the literature describing Rapamycin order the anticancer activity of Cu(II) derivatives of many classes of nitrogen donors including thiosemicarbazone, imidazole (Huang et al., 2005). Among them, pyrazole-containing complexes have been reported to possess antitumor activity which is comparable to that of cisplatin (Sakai et al., 2000; Wheate et

al., 2001; Al-Allaf and Rashan, 2001). In addition, considerable interest in the pyrazole moiety has been stimulated by promising pharmacological, agrochemical and analytical applications of pyrazole-containing derivatives (Eicher and Hauptmann, 1995; Eliguero et al., Olopatadine 1997; Onoa et al., 1999, 2002; Duivenvoorden et al., 2005). Recently, substituted pyrazoles have been used as analytical reagents in the complexation of transition metal ions (Wisniewski et al., 1994; Majsterek et al., 2011). In our previous articles, we have investigated the synthesis, X-ray structures, physicochemical properties and preliminary cytotoxic effect for Cu(II) complexes with pyrazole derivatives as ligands (Miernicka et al., 2008; Budzisz et al., 2009, 2010). Here, we present evaluation of the antioxidant activity of six Cu(II) complexes with three ligands: 5-substituted-3-methyl/phenyl-1-(2-pyridinyl)-1H-pyrazol-4-carboxylic acid methyl ester (1a) or phosphonic acid dimethyl ester (1b) and 1-benzothiazol-2-yl-5-(2-hydroxyphenyl)-3-methyl-1H-pyrazole-4-carboxylic acid methyl ester (1c). We assessed the ability to act these complexes as SOD, CAT and GPx enzyme mimics and to scavenge ROS.