Impact of antibiotics on the microcirculation in local and systemic inflammation

Abstract. The main function of antibiotics is related to their capacity to eliminate a microorganism. In addition to the anti-microbial function of antibiotics, they are known to have anti-inflammatory and vasomodulatory effects on the microcirculation.The ability of non-antimicrobial derivatives of antibiotics to control inflammation illustrates the distinct anti-microbial and anti-inflammatory roles of antibiotics. In this review, we discuss the impact of antibiotics on leukocyte recruitment and the state ofthe microcirculation. Literature reporting the effect of antibiotics in non-infectious inflammatory conditions is reviewed as wellas the studies demonstrating the anti-inflammatory effects of antibiotics in animal models of infection. In addition, the effect ofthe antibiotics on the immune system is summarized in this review, in order to postulate some mechanisms of action for the pro-and anti-inflammatory contribution of antibiotics. Literature reported the effect of antibiotics on the production of cytokines,chemotaxis and recruitment of leukocytes, production of reactive oxygen species, process of phagocytosis and autophagy, andapoptosis of leukocytes. Yet, all antibiotics may not necessarily exert an anti-inflammatory effect on the microcirculation. Thus,we suggest a model for spectrum of anti-inflammatory and vasomodulatory effects of antibiotics in the microcirculation ofanimals in local and systemic inflammation. Although the literature suggests the ability of antibiotics to modulate leukocyterecruitment and microperfusion, the process and the mechanism of action are not fully characterized. Studying this process willexpand the knowledge base that is required for the selection of antibiotic treatment based on its anti-inflammatory functions,which might be particularly important for critically ill patients.Keywords: Antibiotics, microcirculation, leukocyte recruitment, inflammation, immune system