New dammarane-type triterpene saponins from Gynostemma pentaphyllum and their anti-hepatic fibrosis activities in vitro

Jiaogulan (Gynostemma pentaphyllum) tea as one functional food has been commercially available over the world. In this study, the chemical constituents and health properties of Gynostemma pentaphyllum (G. pentaphyllum) has been investigated. Three new dammarane-type triterpenes Gypenoside C, Gypenoside D, Gypenoside E as well as twenty-four known compounds were isolated from the total G. pentaphyllum saponins. The structural determination was accomplished with spectroscopic analysis, in particularly 1D, 2D-NMR and HRESIMS. All the isolated compounds were evaluated for inhibition activities of the growth of human Hepatic Stellate Cells (t-HSC/Cl-6) and compounds 2, 9, 10, 17, 24, 25, 26, 27 showed significant cytotoxic activities. Among them, compound 27 exhibited more excellent inhibitory activities whose IC50 value (24.4 mu M) was 10 fold lower than positive control silymarin. The discovery of new t-HSC/C1-6 inhibitors from G. pentaphyllum expands its usage as a functional food.