Furostanol Saponins from Trillium tschonoskii Promote the Expansion of Human Cord Blood Hematopoietic Stem and Progenitor Cells

Trillium tschonoskii is a medicinal plant known to biosynthesize steroidal saponins. A phytochemical investigation of the rhizomes of T. tschonoskii led to the isolation of nine new furostanol saponins (1–9) and 11 known analogues (10–20). Five of these new compounds were shown to have hydroxy groups at the C-5 and C-6 positions, while two possess a rare aglycone containing carbonyl groups at the C-16 and C-22 positions as well as a Δ¹⁷⁽²⁰⁾ double bond, and the others have conjugated double bonds in the E-ring or have different sugar chains at the C-3 position. All the isolates were tested for their effect on the expansion of human cord blood (CB) CD34⁺ hematopoietic stem and progenitor cells. It was found that CB CD34⁺ cells treated with compounds 6, 7, 9, 10, 14, 15, and 19 showed increased numbers of rigorously phenotype-defined hematopoietic stem cells. Notably, compounds 9, 10, 13, and 14 demonstrated an enhanced ability to increase the percentages and numbers of CB CD34⁺CD38^– cells and multipotential progenitors. The present study is the first to report that furostanol saponins from T. tschonoskii rhizomes can promote hematopoietic stem/progenitor cell (HSPC) expansion.