Effects of roxithromycin on adhesion molecules expressed on endothelial cells of the dermal microvasculature

The objective of the study was to investigate the pharmacological action of roxithromycin, an oral macrolide antibiotic. The effects of roxithromycin on the cytokine-induced expression of endothelial leukocyte adhesion molecule (E-selectin) and intracellular adhesion molecule (ICAM)-1 on endothelial cells of the dermal microvasculature were investigated in vitro using flow cytometry. Roxithromycin at a concentration of 0.5 μg/ml, which is lower than the therapeutic plasma concentration (ordinary daily dose, 150 - 300 mg), significantly inhibited the expression of E-selectin and ICAM-1 on endothelial cells of the dermal microvasculature induced by tumour necrosis factor-α. We conclude that roxithromycin may exert its antiinflammatory action by inhibition of the in vivo expression of adhesion molecules on dermal microvascular endothelial cells.