Antioxidant and Neuroprotective Effect of Organic and Conventional White Grape Juices on Oxidative Stress Induced by Sodium Azide in Cerebral Cortex of Rats

Aims: Diet plays an important role in the prevention of some diseases related to oxidative stress. Although the beneficial effects of a moderate intake of wine are well known, information about the antioxidant properties of grape juice is still limited. Therefore, the objective of this study was to investigate the In vitroneuroprotective effect of conventional and organic white grape juices (Vitis labrusca) on oxidative stress induced by sodium azide in cerebral cortex of 10-day-old-rats.
Study Design: Experimental study using an animal model.
Place and Duration of Study: Biochemistry Laboratory, Methodist University Center – IPA, Porto Alegre, RS, Brazil, between January and December 2012.
Methodology: Cerebral cortex was homogenized and preincubated for 30 minutes with 40% (w/v) conventional or organic white grape juices, furthermore the homogenates were incubated for 1 hour with 5 mM sodium azide in the presence or absence of the juices. The assays of thiobarbituric acid reactive substances (TBARS), carbonyl, sulfhydryl, the activity of the antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) and the production of nitric oxide (NO) were performed in the homogenates.
Results: Sodium azide was able to enhance lipid peroxidation (TBARS) and carbonyl content and also to reduce the non-enzymatic antioxidants defenses (sulfhydryl) in cerebral cortex homogenates. Moreover, sodium azide inhibited the activity of CAT and SOD and enhanced NO levels. Conventional and organic white grape juices were able to prevent the effects caused by sodium azide in TBARS, carbonyl, sulfhydryl and CAT assays.
Conclusion: These results indicated that sodium azide induces oxidative stress in cerebral cortex of young rats and that conventional and organic white grape juices exhibit antioxidant properties capable to ameliorate the oxidative damage caused by this compound.