2.5.6. Superoxide dismutase assay
Serum superoxide dismutase (SOD) activitywas determined with
an enzymatic assay method using a reagent kit (Randox, Crumlin,
U.K.), as described by Sun et al. [20]. One unit of SOD activity was
defined as the amount of enzyme necessary to produce a 50% inhibition
of the NBT reduction rate measured at 550 nm.