Honey modulates oxidative burst of professional phagocytes

The effects of natural honey and its major sugar constituents (i.e. D-fructose, D-glucose, maltose and sucrose) on phagocytic respiratory burst have been studied. Pre-incubated whole blood and isolated leukocytes with honey samples and sugars were induced for phagocytosis and the level of reactive oxygen species (ROS) was monitored by using chemiluminescence assays. Honey samples were found to decrease the luminol-enhanced chemiluminescence in opsonized zymosan-stimulated whole blood and isolated leukocytes with statistically significant differences; indicating inhibition of ROS production including hydrogen peroxide, hydroxyl free radical and hypochlorous acid. Thus honey appears to modify the oxidative burst process by inhibiting phagocytic myeloperoxidase activity. Chemiluminescence assays further showed that among the major sugar constituents of honey, D-fructose in high concentration exerted an inhibitory effect on exocytosis-associated myeloperoxidase catalyzed ROS formation. These results pointed out an immuno-modulatory potential of honey in the course of phagocytosis.