Plant derived triterpenes from Gypsophila elegans M.Bieb. enable non-toxic delivery of gene loaded nanoplexes.

Highlights • The scarcely investigated plant Gypsophila elegans M.Bieb. was screened for triterpenes as novel transfection enhancer. • With a bioassay guided isolation strategy an highly active triterpenoid saponin (gypsophilosid A) was isolated and characterized. • gypsophilosid A enabled an efficient gene delivery of nucleic acids into the cytosol of Neuro-2A-cells. • The combination of suicide gene carrying nanoplexes together with gypsophilosid A imply the potential significance in future gene therapies. • The isolation of the potent gypsophilosid A contributes to the establishment of the recently described sapofection as a transfection method. Abstract To this date, a number of different Gypsophila species from the family of Caryophyllaceae were phytochemically characterized and tested for diverse pharmacological effects. With Gypsophila elegans M. Bieb., we investigated a scarcely explored Gypsophila species, providing a number of potential transfection enhancing triterpene saponins, and so-called sapofection agents. So far triterpene saponins have not been isolated in Gypsophila elegans M.Bieb. Crude extracts from roots and seeds, as well as each purification step were tested for delivery modulation of gene-loaded nanoplexes into neuroblastoma cells. The application of the bioassay guided isolation strategy enabled the assessment of the most active Gypsophila compound, the bisdesmosidic triterpene saponin gypsophilosid A. Gypsophilosid A was isolated by chromatographic techniques, and characterized by electrospray mass spectrometry and intense NMR-spectroscopy, using a variety of 1D and 2D-NMR experiments such as HSQC, HMBC, HQQC, TOCSY and NOESY. In neuroblastoma cells, gypsophilosid A increased the transfection efficiency of gene-nanoplexes up to 80% compared to 2% in the control group without saponin. Our results proved the successful applicability of the implemented methods to detect, isolate and identify saponins, which are biochemically active in terms of transfection. [ABSTRACT FROM AUTHOR]