The extract of Rhizoma Acori tatarinowii promotes proliferation of neural progenitor cells (NPCs) in vitro. (A–C) Monolayer adult hippocampal NPC cultures were treated with AT of different concentrations for 24 h in the reduced growth factor medium (1 ng mL−1 EGF and 1 ng mL−1 bFGF). EdU was added 2 h prior to fixation. Representative images of EdU (red) and DAPI (blue) stainings in the culture treated with DMSO (Ctrl, A) or 0.1 mg mL−1 AT (B) were shown. The percentage of EdU+ cells among total cells in the culture (C) was determined. (D–F) Monolayer adult hippocampal NPC cultures were treated with AT of different concentrations for 14 h in the absence of EGF or bFGF. EdU was added 2 h prior to fixation. Representative images of EdU (red) and DAPI (blue) stainings in the culture treated with DMSO (Ctrl, D) or 1 mg mL−1 AT (E) were shown. (F) Quantification of EdU+ cells (as a percentage of total cells) in the culture. (G–I) Monolayer embryonic neural precursors were treated with AT for 24 h in the reduced growth factor medium. EdU was added 2 h prior to fixation. Representative images of EdU (red) and DAPI (blue) stainings in the culture treated with DMSO (Ctrl, G) or 1 mg mL−1 AT (H) were shown, and the percentage of EdU+ cells among total cells in the culture (I) was determined. (J–L) Embryonic neural precursors were treated with AT of different concentrations for 14 h in the absence of EGF or bFGF. EdU was added 2 h prior to fixation. Representative images of EdU (red) and DAPI (blue) stainings in the culture treated with DMSO (Ctrl, J) or 1 mg mL−1 AT (K) were shown. (L) Quantification of EdU+ embryonic neural precursors (as a percentage of total cells) in the culture. Quantifications are presented as mean ± SEM of eight independent experiments; *P < 0.05, **P < 0.01, ***P < 0.001, analyzed by one-way ANOVA followed by Fisher’s protected least significant difference test; scale bars, 100 μm.