Se-dependent glutathione peroxidase 1 activity in erythrocytes, total glutathione peroxidase 1 and Se-dependent glutathione peroxidase 4 activities in platelets: mean values at 0, 6, 10 and 12 weeks of supplementati

1All values are means ± SDs; ranges in parentheses. Se-dependent activities in erythrocyte samples were determined using tert-butyl hydroperoxide as the substrate in the enzyme assay. Total GPx activities in platelet samples were determined using cumene hydroperoxide as the substrate in the enzyme assay [27], [29]. 2numbers (n) for the GPx4 data are as detailed in the text; placebo (n = 11), 50, 100 and 200 µg/day (n = 12, 14 and 19 respectively), unenriched (n = 14) and Se-enriched (n = 9) due to undetectable GPx4 activity in the platelet enzyme extract compared with the control enzyme extraction buffer. * P<0.05 for the comparison of Time = 12 to Time = 0; ** P<0.005 for the comparison of Time = 12 to Time = 0; # P<0.005 for the comparison with unenriched onion.