The effect of dichloromethylene bisphosphonate on human gingival crevicular neutrophil myeloperoxidase activity.

Neutrophil myeloperoxidase is an important component of the oxygen-dependent microbicidal system and is enzymatically activated in crevicular cells. The purpose of this study was to investigate the effect of dichloromethylene bisphosphonate, a drug used to modify bone resorption, on extracted neutrophil myeloperoxidase activity directly, and indirectly, by means of a luminol-dependent chemiluminescence assay. Enzyme activity was increased, up to a drug concentration of 1 x 10(2) micrograms/ml: 1 x 10(5) neutrophils. Inhibition occurred only at high concentrations, supporting the evidence for low toxicity. This cellular model warrants further investigation with respect both to possible modulation of inflammatory mechanisms relevant to the pathogenesis of periodontitis and other diseases, and to a better understanding of the pharmacological activity of bisphosphonates.