Comparative study of superoxide dismutase activity assays in Crocus sativus L. corms

Superoxide dismutase catalyzes the breakdown of the superoxide radical anion and provides the first line of defense against oxygen toxicity. Its vital importance has made it the subject of numerous investigations. Several assays have been proposed for the detection and quantitation of superoxide dismutase activity, but their use has remained controversial and no comparative studies have been reported. In this investigation, three commonly used methods were compared for the measurement of superoxide dismutase activity in Crocus sativus L. corm extract. The methods, based on a competition between the enzyme itself and another superoxide scavenger, involved respectively cytochrome c reduction, nitro blue tetrazolium reduction, and pyrogallol autoxidation. Because of its accuracy, reproducibility, simplicity and cost benefit, the latter method was the most appropriate.