Luminol-enhanced chemiluminescence after reaction of hydroperoxides with opsonized zymosan.

Luminol-enhanced chemiluminescence (LEC) is very sensitive in detecting free radicals but relatively insensitive for hydroperoxides (hydrogen peroxide, tert-butyl hydroperoxide). However, in the presence of opsonized zymosan (often used for stimulation of phagocytic cells) hydroperoxides also induce LEC, suggesting that free radicals are produced under these conditions. Therefore careful interpretation with respect to the nature of the reactive species is necessary when LEC is used for characterization of zymosan-induced phagocytosis. We studied the properties of zymosan-induced LEC under different test conditions and with various inhibitors. Typical radical scavengers, e.g. nordihydroguaiaretic acid and superoxide dismutase, are strong inhibitors, indicating the importance of the superoxide anion. This system is useful for drug testing with respect to antioxidative or radical scavenging activity.