Effect of roxithromycin on eotaxin-primed reactive oxygen species from eosinophils

Background: The CC chemokine eotaxin not only attracts eosinophils to infla med sites but also promotes adhesion, degranulation and reactive oxygen spe cies production of eosinophils. Reactive oxygen species released from eosin ophils are believed to injure epithelial cells at inflamed sites, resulting in airway hyperresponsiveness. Roxithromycin has been reported to have ant iasthmatic effects, although its mechanism of action is not thoroughly unde rstood. Therefore, the effect of roxithromycin on eotaxin-primed reactive o xygen species production from eosinophils was studied. Methods: Reactive ox ygen species production by eosinophils cultured with or without roxithromyc in was evaluted using luminol-dependnet chemiluminescence. Results: Roxithr omycin inhibited the release of reactive oxygen species from eosinophils ev oked with the calcium ionophore A23187, regardless of pretreatment with or without eotaxin. Conclusion: Roxithromycin may protect epithelial cells at inflamed sites, at least partly by inhibiting the release of reactive oxyge n species from eosinophils. Copyright (C) 2001 S. Karger AG, Basel.