Superoxide Dismutase Activity Assay

According to the ability of SOD to inhibit the reduction of nitroblue tetrazolium (NBT; Sigma, Germany) by superoxide, the activity of SOD was determined. “For assay, 0.067 M potassium phosphate buffer, pH 7.8 was added to 0.1 M EDTA containing 0.3 mM sodium cyanide, 1.5 mM NBT and 0.1 mL of sample. Then, 0.12 mM riboflavin (Sigma, Germany) was added to each sample to initiate the reaction and was incubated for 12 min. The absorbance of samples was read on a Genesys 10 UV spectrophotometer (CECIL-2501, England) at 560 nm for 5 min. The amount of enzyme required to produce 50% inhibition was taken as 1 U and results were expressed as U/mg protein”.^{24 (link)}