Effect of bleomycin on the generation of active oxygen species in human neutrophilis

Bleomycin (BLM) has been frequently used for the treatment of oral cancer. BLM is thought to produce active oxygen species such as superoxide anion, which have been shown to bring on tissue damage. It is therefore suggested that active oxygen species may have an antitumor effect. This study was undertaken to clarify the effect of BLM on active oxygen species generation in human peripheral blood neutrophils.For this purpose, peripheral blood neutrophils were obtained from normal volunteers and then luminol dependent chemiluminescence (LDCL) was measured to estimate the generation of active oxygen species. Phorbol myristate acetate (PMA), N-formyl-methionyl-leucyl-phenylalanine (FMLP) or serum opsonized zymosan (OPZ) was used as stimulants of LDCL generation.As a result, at concentrations over 5 μg/ml BLM, LDCL without those stimulants was slightly increased. LDCL stimulated by PMA or FMLP is obviously increased by the addition of O.1 μg/ml BLM or 0.01 μg/ml, respectively. While LDCL induced by OPZ was not increased by BLM. 5-fluorouracil (5-Fu) an antitumor agent, had also no effect on LDCL generation.These results suggest that BLM may promote or enhance the generation of active oxygen species in human neutrophils. Through this function, BLM may exhibit an antitumor activity.