Neuroprotective effects of triterpenoid saponins from Medicago sativa L. against H2O2-induced oxidative stress in SH-SY5Y cells.

Medicago sativa L. is a forage legume plant widely distributed in all continents. Six new triterpenoid saponins, Medicagosides A-F (1-6) and five known ones (7-11) were isolated from M. sativa. Their structures were determined via HRESIMS, 1D and 2D NMR analysis. Biologically, all the isolates displayed neuroprotective activities against H2O2-induced damage in SH-SY5Y cells. Among them, compounds 1, 3-5 and 10 exhibited striking neuroprotective activities at 100 µM, restoring cell viability range from 79.66% to 89.03%, relative to 79.46% (100 µM) of Trolox used as the positive control.