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In vitro interaction between spiramycin and polymorphonuclear neutrophils oxidative metabolism
I Moutard1, B Gressier, C Brunet
1Laboratoire de Pharmacologie, Pharmacocinétique et Pharmacie Clinique, Faculté des Sciences Pharmaceutiques et Biologiques, Lille, France.
Pharmacological Research
|May 29, 1998
Summary
Spiramycin at therapeutic doses enhances polymorphonuclear leukocytes (PMNs) superoxide anion production, boosting their antimicrobial activity. This pro-oxidant effect, observed with bacterial and fMLP stimulation, suggests potential therapeutic benefits in combating infections.
Area of Science:
- Immunology
- Pharmacology
- Microbiology
Background:
- Polymorphonuclear leukocytes (PMNs) are crucial for host defense against microbial invasion, utilizing reactive oxygen species (ROS).
- Antibiotic effects on phagocyte functions, including ROS production, are an area of ongoing research.
- Understanding how antibiotics modulate PMN oxidative burst is vital for optimizing antimicrobial therapy.
Purpose of the Study:
- To evaluate the in vitro activity of the macrolide spiramycin on PMN respiratory burst functions.
- To assess spiramycin's effect on superoxide anion (O2.-) generation stimulated by various agents.
- To explore the potential therapeutic implications of spiramycin's influence on PMN bactericidal activity.
Main Methods:
- In vitro assessment of superoxide anion (O2.-) generation in PMNs.
- Stimulation of PMNs using N-formyl Met-Leu-Phe (fMLP), phorbol 12-myristate 13-acetate (PMA), calcium ionophore (A23187), and Staphylococcus aureus.
- Measurement of O2.- production at different spiramycin concentrations.
Main Results:
- Therapeutic concentrations of spiramycin increased O2.- generation in bacteria and fMLP-stimulated PMNs (26-34%).
- A weaker pro-oxidant effect was noted with PMA stimulation, and a weak antioxidant effect with A23187.
- Higher spiramycin concentrations inhibited O2.- production, with IC50 values varying by stimulus.
Conclusions:
- Spiramycin's effect appears to involve intracellular mechanisms, likely NADPH-oxidase activation, rather than simple chemical interaction.
- The observed enhancement of O2.- production at therapeutic concentrations suggests a potential to augment PMN bactericidal activity.
- This pro-oxidant effect of spiramycin could be therapeutically beneficial in managing microbial infections.