A hederagenin-type triterpene saponin, sumbulianoside a from Cephalaria sumbuliana and its potent immunomodulatory activity against seasonal flu virus H3N2

Abstract

A new hederagenin-type triterpene saponin; hederagenin 28-O-β-D-galactopyranosyl-(1→6)-β-D-glucopyranosyl ester named sumbulianoside A (1), together with twelve known saponins were isolated from the n-butanol extract of Cephalaria sumbuliana (Caprifoliaceae) from which, one known saponin, dipsacus saponin A (2) was isolated, for the first time from Cephalaria species. The structures of the isolated compounds were elucidated by 1 D and 2 D NMR and HRESIMS analyses. Cytotoxic activities were investigated on A549, Hela, PANC1, SHSY5Y cells and non-cancerous cell HEK293 by MTT method and immunomodulatory activities were evaluated against activated H3N2 seasonal virus in whole blood by measuring IL-4, IFN-γ, IL-1β cytokine level with ELISA. According to the cytotoxicity results, compounds 1 and 2 did not possess significant cytotoxicity, while only compound 2 induced significant IL-4 production (** p<.001) against H3N2 showing a possible Th2 response and antibody production. All compounds had no effect on cytokine release (p > 0.5).

Graphical Abstract

Keywords:

• Cephalaria sumbuliana
• Caprifoliaceae
• sumbulianoside A
• saponin
• cytotoxic activity
• immunomodulatory activity
• H3N2

Acknowledgements

The authors would like to thank Research Grant Office of Ege University (FYL-2019-20471) for financial support, acknowledge to Prof. Dr. H. Sumbul and Assoc. Prof. Dr. R. S. Gokturk for collection and identification of the plant. Thanks are also due to TUBITAK (Marmara Research Center, Gebze, Kocaeli, Turkey) for NMR and HR-ESI/MS analysis. And finally, we thank Ege University Science and Technology Centre for running NMR (400 MHz) spectra and Ege University, Central Research Test and Analysis Laboratory Application and Research Center for GC-MS analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.