Modified Diet Supplementation With Group B Vitamins Changes Antioxidant Defense Activity Of Brain

The research aimed at effect of modified diet and supplementation with synthetic B vitamins on brain antioxidant status evaluation. Forty male Wistar rats were divided into 4 groups (n = 10); group I - fed Basic Diet (BD), groups II-IV - Modified Diet (MD), where wheat flour replaced 83.5 % wheat and sucrose replaced 50 % maize. Groups I-II received only water, while group III (MD + AS) was given an aqueous vitamins solution supplementing deficiency from diet modification (MD + Adequate Supplementation: B₁-0.94, B₂-0.48, B₆-0.5, niacin-1.9 mg); group IV (MD + ES) received a solution in order to supplement deficiency resulting from the change in diet and recommended prophylactic dose of vitamins (MD + Excessive Supplementation: B₁-3.1, B₂-2.3, B₆-2.4, niacin-6.65 mg). The experimental phase lasted 6 weeks. Blood serum was examined, to determine glucose and iron concentration; determination of FRAP in plasma, in brain tissue the activities of GST, GPx, CAT, SOD, SH content, and FRAP. It was found that MD and MD + AS did not influence cereal antioxidant status. In brain tissue, MD + ES group exhibited an increased glycaemia (7.49 mmol×l^-1 p = 0.038) and increased activity of antioxidant enzymes activity (GST 0,099 U/mg protein p = 0.005; GPx 0,039 U/mg protein p = 0.007). Brain tissue of rats also exhibited larger content of protein bond SH in comparison to BD, MD and MD + AS groups (SH 414.6 mmol/g wet weight p < 0.001; p < 0.005). These findings suggest that, an excessive supplementation with vitamins B and niacin, in sucrose rich diet, may lead to enhancing activity of cellular antioxidant defense in brain tissue of rats.