New results on saponins and saponin-rich plant-extracts enabling synergistic cytotoxicity with type-I-RIPs/lectins

The synergistic cytotoxicity between saponins and lectins, especially the naturally very low cytotoxic activity showing type-I-RIPs (ribosome-inactivating protein type I)/lectins is known for years by now [1]. It has become a promising strategy in anti-cancer research [2]. While the pre-appliance of certain saponins can drastically amplify the cytotoxicity of the type-I-RIPs [3, 4], it may also minimize the required effective dose of these very expensive (especially when linked to human antibodies) and time-consuming to purify/to create substances [5].

In our work we searched for new saponins and saponin-rich plant-extracts capable of increasing the cytotoxicity of the naturally very low cytotoxic activity showing lectin saporin, considered as a standard type-I-RIP. The spotlight of our research was put on the plant-family of Caryophyllaceae, but saponins and saponin-rich plant-extracts from other plant-families were also tested when fulfilling certain structural conditions. All tests were performed in a cell culture model using ECV-304 cells. The cytotoxicity was measured by MTT assay and DNA quantification.

References: 1. Hebestreit P, Melzig MF (2003) Planta Med 69: 921–925. 2. Bachran C et al. (2009)J Immunother 32: 713–725. 3. Hebestreit P et al. (2006) Toxicon 47: 330–335. 4. Weng A et al. (2008) Chem Bio. Int 176: 204–211. 5. Bachran C et al. (2010) Brit J Pharmacol 159: 345–352.