Neurogenesis is crucial during the human lifespan for
the maintenance
of synaptic plasticity and normal function. The impairment of hippocampal
neurogenesis in adults may lead to neurodegenerative disease, such
as Alzheimer’s disease. Miquelianin (quercetin-3-O-β-d-glucuronide, Q3GA) is a constituent of the nuciferine
leaf polyphenol extract (NLPE), and it has protective effects against
neurodegeneration. In this study, we examined the effect of the NLPE
on neurogenesis and the mechanisms underlying Q3GA on neurogenesis.
We fed 24-week-old male C57BL/6 mice with 0.1 or 0.25% NLPE for 2
weeks. NLPE treatment increased small spindle-shaped stem cell numbers
in the subgranular zone and the number of doublecortin (DCX)- and
neuron-specific nuclear protein (NeuN)-expressing neurons. HT22, a
hippocampal cell line, treated with Q3GA revealed significant neurite
growth and upregulated TrkR and PI3K/Akt levels. The evidence from
a model of retinoic acid-induced SH-SY5Y cell differentiation showed
that Q3GA or NLPE increases neurite growth significantly. Taken together,
the NLPE containing Q3GA to promote neurogenesis involving the upregulation
of TrkR and the PI3K/Akt signaling pathway might be potentiated as
an alternative strategy for the treatment of neurodegeneration.