Figure 8. The effect of 3,4,5-tricaffeoylquinic acid (TCQA) on gene expressions related to bone morphogenetic protein (BMP) signaling pathway. Human neural stem cells (hNSCs) were treated with differentiation medium with or without 10 μM TCQA for 24 h. Genes expressing BMP ligand BMP5, BMP receptor 2 and SMAD5 downstream BMP signaling pathway as well as the neuronal differentiation transcription factor NEUROD1 were increased by TCQA (A). Genes related to p38–p53 signaling pathway regulating G0/G1 cell cycle arrest of hNSCs activated by the BMP signaling pathway were increased by TCQA (B). Genes related to the Cdc42 signaling pathway regulating neurite extension and activated by the BMP signaling pathway were increased by TCQA (C). Data was set as % of undifferentiated control. Data were presented as mean ± SD. ** P < 0.01 Compared with undifferentiated control.