, 2004). In the present work, as rats were not submitted to exercise protocols, they were not excessively active under CR diet and did not assume anorexic features, also observed by blood parameters, including normal proteinemia and glycemia (anorexia

this website nervosa normally induces hypoglycemia). Regarding glial function, our laboratory recently reported that CR was able to modulate astrocyte functions by increasing glutamate uptake and GS activity, all together suggesting a possible CR-induced neuroprotective effects via modulation of astrocytic functions ( Ribeiro et al., 2009). Now, we wondered if GSH levels may differ upon CR, depending on the particular area of the brain. Our data showed that hippocampal and cerebral cortical GSH content was significantly higher in the CR scenario than in the control groups. Since, GSH is an extremely important non-enzymatic antioxidant for CNS; these data may provide some evidence for delineating the mechanisms by which CR may exert protective actions in the brain. Basal values of CAT activity, TBARS levels and NO production were not different between groups except for ROS production where CR diet-fed rats gave values Alpelisib concentration significantly lower than the control groups, especially in

the cerebral cortex where values differed from 26% in the Hc to 14% in the Cx itself. High levels of ROS can trigger lipid, protein and DNA damage in cells. Though hydrogen peroxide is not a free radical, it can generate hydroxyl as well as similar reactive radicals, extending oxidative damage (Halliwell, 2006). In this context, one could speculate during that a significant decrease in basal ROS production could become an important strategy for the maintenance of a healthy brain.

Besides, the glutathione peroxidase is capable of eliminating peroxides by reducing them to H2O or alcohols, with GSH as reducing substrate (Dringen, 2000). In this particular case, our data showed that the CR diet was also able to significantly reduce (about 18%) GPx activity in both Hc and Cx brain structures. Based on our past and current results we hypothesized (Fig. 8) CR-mediated modulation of neural cells may be a result of lower metabolic and mitochondrial activity (Bordone and Guarente, 2005) with a subsequent decrease of mitochondrial ROS production as we have demonstrated in this study. A decreased CR-induced production of ROS could negatively modulate GPx activity and consequently, it would justify why the detected levels of GSH were actually increased. Finally, we have demonstrated that the CR group had 30% less of hippocampal DNA damage than the control group. Such data is in agreement with recent works showing that CR was able to reverse age-related alterations in DNA damage by enhancing its repair and reducing mutations (Heydari et al., 2007).