Antagonism of licorice on selectin-mediated eodinophil and neutrophil adhesion

Kim, Mi Kyeong

Abstract

BACKGROUND AND OBJECTIVE: Early in inflammation, adhesion occurs between leukocytes and endothelium where selectins bind to sialyl Lewis x(Sle,) and related oligosaccharides. We tested glycerrhetinic acid(GA), msjor anti-inflammmatory component of licorice, for its ability to inhibit selectin-mediated adhesion of human eosinophils and neutrophils in vitro. MATERIAL AND METHOD: Neutrophils and eosinophils were isolated by density grsdient centrifugation and eosinophils were further purified by immunomagnetic negative selection. Adhesion to unstimulated or IL-1 p-stimulated(5ug/ml, 4-6hr, 37C) umbilical vein endothelial monolayers was tested under static or rotating conditions, where adhesion is E- or L-selectin dependent, respectively. P-selectin-dependent adhesion was tested on immobilized platelets treated with or without TPA(10-7M, 10mins, RT). Stimulus-induced adhesion was always at least four-fold higher than without stimulus, and selectin dependence was confirmed with specific blocking monoclonsl antibody RESULT: All three kinds of selectin-mediated eosinophil and neutrophil adhesion were inhibited by GA and they were reversible without affecting viability.
CONCLUSION
The ability of GA to interfere with the selectin mediated adhesion may contribute the one of the mechanism of the anti-inflammatory effects by licorice.