Figure 4. The effect of 3,4,5-triCaffeoylquinic acid (TCQA) on cell viability of human neural stem cells (hNSCs). hNSCs in undifferentiated state (A), induced differentiation for 96 h (B) and induced differentiation and treated with TCQA for 96 h (C). Time after differentiation, hNSCs were treated with TCQA (1, 5, 10, 20 μM) for 24, 48, 72, and 96 h (D). After the treatment, cell viability was measured by MTT assay. Data was set as % of control. Data were presented as mean ± SD. ** P < 0.01 Compared with control group.