title: Macromolecular interactions of triterpenoids and targeted toxins: role of saponins charge.
abstract: Macromolecular interaction of protein toxins with certain plant triterpenoids holds potential for application in tumor therapy. The ability of only certain saponins to enhance the endosomal escape of toxins specifically in tumor cells was evaluated and set into correlation with the electrophoretic mobility. Saponins from Saponaria officinalis Linn, were selected as a lead to understand this evolutionarily conserved principle in detail. Agarose gel electrophoresis was utilized to procure pure saponin fractions with different electrophoretic mobility, which were tested for their ability to enhance the toxicity by live cell monitoring. Five fractions (SOG1-SOG5) were isolated with a relative electrophoretic mobility of (-0.05, 0.41, 0.59, 0.75 and 1.00) and evaluated using thin layer chromatography, HPLC, and mass spectroscopic analysis. Cytotoxicity experiments revealed highest effectiveness with SOG3. Live cell imaging experiments with SOG3 revealed that this saponin with a specific REM of 0.59 could assist in the lyso/endosomal release of the toxic payload without affecting the integrity of plasma membrane and could lead to the induction of apoptosis. This charge dependent enhancement was also found to be highly specific to type I ribosome inactivating proteins compared to bacterial toxins. Charge interaction of plant toxins and saponins with tumor cells, plays a major role in toxin specific modulation of response. The finding opens up newer ways of finding protein saponin interaction conserved evolutionarily and to test their role in endosomal escape of therapeutic molecules.
authors.affiliation: Institute for Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany. Electronic address: mayank.thakur@charite.de.
authors.forename: Mayank
authors.initials: M
authors.lastname: Thakur
authors.forename: Alexander
authors.initials: A
authors.lastname: Weng
authors.forename: Alexandra
authors.initials: A
authors.lastname: Pieper
authors.forename: Katharina
authors.initials: K
authors.lastname: Mergel
authors.forename: Benedicta
authors.initials: B
authors.lastname: von Mallinckrodt
authors.forename: Roger
authors.initials: R
authors.lastname: Gilabert-Oriol
authors.forename: Cornelia
authors.initials: C
authors.lastname: Görick
authors.forename: Burkhard
authors.initials: B
authors.lastname: Wiesner
authors.forename: Jenny
authors.initials: J
authors.lastname: Eichhorst
authors.forename: Matthias F
authors.initials: MF
authors.lastname: Melzig
authors.forename: Hendrik
authors.initials: H
authors.lastname: Fuchs
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects; D008247:Lysosomes / Q000187:drug effects; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry; D029750:Saponaria / Q000737:chemistry; D012503:Saponins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization; D014118:Toxins, Biological / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D012503:Saponins; D014118:Toxins, Biological
keywords: Endosomal escape; Real time evaluation; Saponaria saponins; Tumor targeted toxins