Influence of selenium and zinc biofortificated wheat on deposition in tissue, expression of antioxidative genes in Sprague-Dawley rats

AIMS: The aim of this study was to determine deposition of selenium (Se) and zinc (Zn) in liver and blood after changes in their content in food ; and whether this affects gene expression of catalase, superoxide dismutase (SOD) and glutathione peroxidases (GPx). METHODS: 4-weeks old male Sprague-Dawley rats were divided into 3 groups: control group fed with low- Se/low-Zn wheat ; rats fed with high-Se/low-Zn wheat ; and group fed with high-Zn/low-Se. After 10 weeks rats were sacrificed to analyze deposition of Se and Zn in liver and blood, and to determine liver gene expression of antioxidative enzymes by q-rtPCR. RESULTS: There is a significant up-regulation of GPx1 and GPx8 in high-Zn/low-Sn group, and GPx7 in high-Se/low-Zn, both compared to control group. In addition, expression of GPx8 in high-Zn/low-Se group was significantly higher compared to high- Se/low-Zn group. Rats fed with high-Se/low-Zn wheat had significantly higher deposition of Se in blood and liver compared to the other groups. There was no significant difference in gene expression of catalase and SOD. CONCLUSION: These results suggest that high food Zn content increases transcription of GPx isoforms in the liver, hypothetically by zinc finger transcription factor ZNF143. Even though there was significant Se deposition in rat tissue, this affected only transcription of GPx7 gene.