Flavonoid Glucosides from Ziziphus jujuba Seeds Improve Learning and Memory in Mice

The effect of flavonoid glucosides from seeds of Ziziphus jujuba var. spinosa (Bunge) Hu ex H.F. Chow, Rhamnaceae, on learning and memory was investigated in mice with scopolamine-induced dysmnesia. In Y-maze and passive avoidance test, the results showed that the flavonoid-rich extract could decrease the number of errors and increase the latency time significantly, indicating remarkable activities of the content of flavonoids in ameliorating the learning and memory function. A new high-performance liquid chromatography coupled to electrospray mass spectrometry method was developed to identify and quantify the main flavonoids in the analyzed plant material. Five major flavonoid C -glucosides were qualitatively and quantitatively identified as spinosyn, isovitexin, swertisin, 6”'-feruloylspinosin, and 6”'- p -coumaroylspinosin. In addition, the flavonoid-rich extract also increased the learning ability of the nematode Caenorhabditis elegans strain GMC101, a model of amyloid-β protein expression. Spinosin accounts for this ameliorating performance, and this is associated with its significant effect in reducing Aβ-induced toxicity. Graphical abstract