The effects of some triterpenoid saponins on glucose transport in Ehrlich ascites tumor (EAT) cells were examined by measuring 2-deoxy-D-glucose (2-DG) uptake. The correlation of the effects with those on the growth of a human T-cell line (MT-4) and the replication of human immunodeficiency virus in MT-4 cells was also studied. Chikusetsusaponin Ia isolated from rhizomes of Panax japonicus C. A. Meyer (Araliaceae) inhibited the 2-DG uptake (IC50 = 76.3 microM) in a competitive fashion with respect to 2-DG (Ki = 0.32 mM) and the growth of MT-4 cells with CC50 of 84.4 microM, whereas it did not show any significant anti-HIV-1 activity. In contrast, zingibroside R1 isolated from rhizomes of Panax zingiberensis Wu et Feng (Araliaceae) showed some anti-HIV-1 activity, which was found to be superior to that of glycyrrhizin, as well as the inhibitory effects on the 2-DG uptake by EAT cells (IC50 = 91.3 microM) and the growth of MT-4 cells (CC50 = 46.2 microM).