In vitro activity: A-205804 selectively inhibits the surface expression of the cell adhesion molecules ICAM-1 and E-selectin in human endothelial cells. A-205804 inhibites the IL-1β-induced expression of E-selectin (IC50 = 20 nM) and ICAM-1 (IC50 = 10 nM) with essentially the same level of potency as that for TNFα-induced expression. For reasons which are unclear, the ability of A-205804 to inhibit PMA-induced E-selectin expression is significantly reduced (IC50> 1000 nM), but A-205804 is a potent inhibitor of ICAM-1 expression (IC50 = 40 nM) using this protein-kinase C-activating agent.

Cell Assay: In human vascular endothelial cells using whole-cell high-throughput assay, it was shown that A-205804 exhibited potent and selective inhibition to E-selectin and ICAM-1 with low concentrations. Further, it was revealed that A-205804 inhibited E-selectin and ICAM-1 expressions by translocating to cell nucleus and noncovalently associated with macromolecules of molecular weight greater than 650 kDa when tested with human umbilical vein endothelial cells (HUVECs).

J Med Chem. 2001 Oct 11;44(21):3469-87; J Med Chem. 2001 Mar 15;44(6):988-1002.