Saponinum album, a mixture of saponins with an aldehyde function bound at C4 from Gypsophila species, increased the cytotoxicity of lectins like agrostin and saporin by enhancing its penetration through the cell membrane. The effect was attenuated by latrunculin, an inhibitor of endocytosis, and by bafilomycin, an inhibitor of transport from early to late endosomes and lysosomes. In contrast, the effect was not influenced by brefeldin A that causes dissolution of the Golgi stacks and by the addition of different monosaccharides. The toxicity of other peptidic toxins was only slightly enhanced by the saponins indicating a specific interaction between lectins and saponins present in Caryophyllaceae.