A coelenterazine-based luminescence assay to quantify high-molecular-weight superoxide anion scavenger activities.

In all living cells, levels of reactive oxygen species are kept in check by antioxidative activities. Superoxide radicals are dismutated by superoxide dismutases, by other enzymes and by nonenzymatic compounds. This protocol describes the quantification of superoxide scavenging activities (SOSA). It is based on the inhibition of chemiluminescence emitted by coelenterazine when oxidized by superoxide. SOSA is a summary parameter comprising all high-molecular-weight superoxide scavengers in a biological sample. Enzymes and nonenzymatic scavengers can also be distinguished. The SOSA assay is quick, reproducible and applicable to fields as diverse as medical diagnostics, food sciences, or agriculture. The protocol presented here requires about 2 working days to complete.