Investigation of the anti-inflammatory and membrane-stabilizing potential of spiramycin in vitro.

The effects of the 16-member macrolide spiramycin (2.5-80 mg/L) and the 14-member agent clarithromycin on the production of superoxide by activated human neutrophils were compared in vitro and related to membrane-stabilizing activity. Superoxide production was measured by lucigenin-enhanced chemiluminescence with N-formyl-L-methionyl-L-leucyl-L-phenylalanine (1 microM) as the stimulus, and membrane-stabilizing activity was measured by a haemolytic procedure. Clarithromycin, but not spiramycin, caused dose-related inhibition of superoxide production by activated neutrophils and also protected erythrocytes against haemolysis, while spiramycin possessed only weak membrane-stabilizing activity. These observations underscore the apparent association between the anti-inflammatory and membrane-stabilizing properties of macrolides.