Ginsenosides Rb1, Rb2, Rc and Rg1 inhibited steroidogenesis induced by a maximally active dose of corticotropin in isolated rat adrenal cells. The galactose-binding lectins from Momordica charantia seeds and Trichosanthes kirilowii tubers and mannose-binding concanavalin A did not affect basal corticosterone production. The lectins potentiated steroidogenesis induced by a submaximal dose of corticotropin but were without effect on steroidogenesis induced by a maximally active dose of corticotropin. Momordica charantia insulin-like peptide did not affect steroidogenesis.