In the biological system iron and iron-mediated generation of reactive oxygen species (ROS) is one of the most important issues in the area of infection and immunity. Inhibition of iron-mediated generation of ROS by some molecules might give some clues for treatment of many diseases in humans and animals. Deferoxamine (DFO), as a strong iron chelator, would be one of the drugs of choices for this approach. In economically important animals, especially in bovine, environmentally originated pathogens are big problem, and neutrophils are key players in protecting of bovine from infection. These non-specific immune cells have enormous potentials to eventually kill engulfed microbes via mainly intracellular ROS. Our preliminary results from the inhibitory effect of DFO on some ROS show that DFO application in immunobiological system could be a promising pharmacological approach to improve innate immunity in immunecompromised cows. To investigate the influence of DFO on neutrophil bactericidal activity, the neutrophils were isolated from eight healthy dairy cows; the effect of DFO at concentrations of 0 and 1 mM on neutrophil ROS production was measured both by a phorbol 12-myristate 13-acetate (PMA)-induced luminol enhanced chemiluminescence (CL) and by a superoxide dismutase-inhibitale reduction of ferric cytochrome c assay as well as by the horseradish peroxidase-catalysed oxidation of fluorescent scopoletin to a nonfluorescent product for hydrogen peroxide production assay. The CL response of neutrophils pre-incubated with DFO remarkably increased compared with control values. Neutrophil superoxide anion production and hydrogen peroxide prodauction in DFO traeted groups were also significally higher than non-treated group. The values of luminol-dependent CL, superoxide anion production and hydrogen peroxide production of neutrophils pre-exposed to DFO confirm the intracellular ROS production of neutrophils, suporting an increased bactericidal efficiency of bovine neutrophils by DFO application in vivo. Further studies are in progress to explain this finding in bovine.

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