Effects of oleanane-type triterpenoids from fabaceous plants on the expression of ICAM-1

We examined the inhibitory effects of oleanane-type triterpenoids from fabaceous plants on the TNF-alpha-induced expression of cell adhesion molecules on THP-1 human monocytic leukemia cells and compared them with a glucocorticoid dexamethasone. In a cell-based ELISA, abrisapogenol E, soyasapogenols B and C, soyasapogenol B, kuzusapogenol B-methyl ester, and oleanolic acid significantly inhibited intercellular adhesion molecule (ICAM-1) expression. Moreover, these triterpenoids showed the same activity as dexamethasone. On the other hand, the absence of hydroxyl group at C-24 position of sapogenin rather to increase ICAM-1 expression compared with the untreated control. We concluded that the activity of oleanane saponins and sapogenins against ICAM-1 expression are dependent upon the position of the hydroxyl group, and in particular upon the status of the C-21 and C-24 positions and of the glycosyl group at C-3 position.