Immunosuppressive nitrogen-containing triterpenoid saponins from Mussaenda erosa and the therapeutic efficacy of heinsiagenin A in a murine lupus erythematosus model.

Eight novel nitrogen-containing triterpenoid saponins, designated mussaerosides A-H (1-8), and ten known ones (9-18) were obtained from the aerial parts of Mussaenda erosa Champ (Rubiaceae). Structural characterization was achieved through spectroscopic techniques and chemical derivatization. Immunosuppressive screening of the saponins and sapogenin heinsiagenin A revealed potent inhibition of T- and B-lymphocytes proliferation, and the latter exhibited potent inhibitory activities against the proliferation of ConA-induced T lymphocyte (CC50 = 22.16 μM, IC50 = 2.33 μM, SI = 9.51) and LPS-induced B lymphocyte (CC50 = 22.16 μM, IC50 = 0.71 μM, SI = 31.21). Therapeutic efficacy of heinsiagenin A was further corroborated in vivo in the MRL/lpr lupus model, with notable mitigation of disease phenotypes.