Abstract
The effects of potassium iodide, colchicine and dapsone on the in vitro generation of polymorphonudear leukocyte (PMN)-derived oxygen intermediates were investigated. These three drugs have beneficial effects on those conditions in which PMNs play an important pathogenetic role. Three oxygen intermediates, superoxide anion (O2), hydrogen peroxide (H2 O2), hydroxyl radical (OH·) and chemiluminescence were included in assay studies. Dose response studies were performed with therapeutic doses of the drugs (10 μM–1 mM). We found that both potassium iodide and dapsone significantly suppressed the generation of oxygen intermediates, except for O2. Colchicine decreased OH · production. Our results show that these agents to some extent exert their anti-inflammatory effects by interfering with the PMN-dependent production of oxygen intermediates, thus conferring protection from auto-oxidative tissue injury. This may account for their clinical efficacy in many PMN-mediated dermatological diseases.