Active components from Siberian ginseng (Eleutherococcus senticosus) for protection of amyloid β(25-35)-induced neuritic atrophy in cultured rat cortical neurons

Not only neuronal death but also neuritic atrophy and synaptic loss underlie the pathogenesis of Alzheimer's disease as direct causes of the memory deficit. Extracts of Siberian ginseng (the rhizome of Eleutherococcus senticosus) were shown to have protective effects on the regeneration of neurites and the reconstruction of synapses in rat cultured cortical neurons damaged by amyloid beta (A beta)(25-35), and eleutheroside B was one of the active constituents. In this study, a comprehensive evaluation of constituents was conducted to explore active components from Siberian ginseng which can protect against neuritic atrophy induced by A beta(25-35) in cultured rat cortical neurons. The ethyl acetate, n-butanol and water fractions from the methanol extract of Siberian ginseng showed protective effects against A beta-induced neuritic atrophy. Twelve compounds were isolated from the active fractions and identified. Among them, eleutheroside B, eleutheroside E and isofraxidin showed obvious protective effects against A beta(25-35)-induced atrophies of axons and dendrites at 1 and 10 mu M.