, 2009). The activation of excitatory amino-acid receptors by glutamate or N-methyl-D-aspartic acid has been
known to accompany the generation of ROS and reactive nitrogen species, such as superoxide anion radicals, hydrogen peroxide, nitric oxide and peroxide anions, that lead to neuronal damage (Mori et al., 2004). Studies have shown that polyphenols, such as 6-methylflavanone (Hall et al., 2005), (−)-epigallocatechin gallate (Vignes et al., 2006), flavan-3-ol derivatives (Fernandez et al., 2008) and resveratrol (Li et al., 2010), are selleck chemical positive modulators of GABA receptors. Grape juices are rich in polyphenols, which have important antioxidant effects (Dani et al., 2007). In this study, we evaluated the neuroprotective and anticonvulsant effects of organic and conventional grape juices in an experimental model in which epilepsy was induced in Wistar rats by PTZ. Furthermore, we also evaluated possible behavioral changes and the phenolic profiles of rats treated with the juices. Although both grape juices contain flavan-3-ol
derivatives and resveratrol, neither were able to inhibit the seizures induced by PTZ (as measured by tonic-clonic seizure time, total seizure time, number of seizure and number of seizures reaching stage five on Racine’s scale) (Fig. 2). This result could be explained by the fact that the amounts of polyphenols present in grape juices are lower than those reported to be effective in binding to GABA receptors (Fernandez et al., 2008 and Li et al., 2010). PTZ may trigger a variety of biochemical processes, FG-4592 including the activation of membrane phospholipases, proteases and nucleases, causing the degradation of membrane phospholipid metabolism and proteolysis and protein phosphorylation; thus, PTZ could lead to a release of lipid peroxides and free radicals (Naziroglu et al., 2009, Obay et al., 2008 and Silva et al., 2009). The present study shows that PTZ induces an increase in oxidative damage Org 27569 through lipid and protein oxidation in the hippocampus, cerebellum and cortical tissues assayed. The rats treated with organic and
conventional grape juices showed an attenuation in the PTZ-induced increase in lipid and protein oxidation in all brain tissues (Table 3, Table 4 and Table 5). Similar results were found with α-tocopheryl-L-ascorbate-2-O-phosphate diester (Yamamoto et al., 2002), lipoic acid (Militão et al., 2010), erdostein (Ilhan et al., 2005) and isopulegol (Silva et al., 2009) in different experimental models of induced epilepsy in rats. The inactivation of ROS can be accomplished by antioxidant enzymes. The enzyme SOD plays a key role in detoxifying the superoxide anions from hydrogen peroxide and oxygen (Fridovich, 1998). The hydrogen peroxide that is formed may be decomposed by CAT in water and oxygen (Naziroglu et al., 2009).