Influence of natural and synthetic compounds on cell surface expression ofcell adhesion molecules, ICAM-1 and VCAM-1

Various natural and synthetic compounds including alkaloids, terpenoids and phenolics were tested for inhibition of the cell surface expression of int ercellular adhesion molecule-1 (ICAM-1) and Vascular cell adhesion molecule -1 (VCAM-1), both of which are crucial in the regulation of immune response and inflammation. Of 40 compounds tested, two compounds significantly down regulated the expression of VCAM-1 on murine endothelial cells (F-2) and te n compounds that of ICAM-1 on mouse myeloid leukemia cells (M1). Sanguinari ne chloride (5) and isoliquiritigenin (13) were capable of lowering the lev els of both ICAM-1 and VCAM-1. The structure-activity relationships study o n chalcone and flavone derivatives related to 13 suggested that the inhibit ory activity of the chalcone derivatives is attributable to the 4-hydroxy g roup as well as the possible coplanarity between the phenyl ring and the ad jacent conjugated ketone.