Abstract: Objective To observe the effects of total saponins of Astragalus (TSA) on neural stem cells (NSCs) differentiating to neuron in vitro and the best concentration, as well as the role of Wnt/β-catenin signaling pathway in it. Methods NSCs from the cerebral cortex of a neonatal rat were cultured and identified. The possible effective concentration of TSA was screened with Cell Counting Kit-8 (CCK-8). The third generation of NSCs was induced as normal group (without TSA) and various concentration of TSA groups for seven days. The expression of microtubule-associated proteins (MAP-2) and glial fibrillary acidic protein (GFAP) was detected with indirect immunofluorescence and Western blotting to detect the ratio of neuron and astrocyte. Then, the third generation of NSCs was induced as normal group (without TSA), the best concentration of TSA group, TSA group and inhibitor ICG-001 group, and ICG-001 group, for seven days, and the expression of Wnt3/3a, β-catenin and neurogenin 1 (Ngn1) was detected with Western blotting. Results TSA promoted the NSCs proliferation in the concentration of 1×10^-4 mol/L, 1×10^-5 mol/L and 1×10^-6 mol/L (P < 0.001), and increased the proportion of neurons, especially in the concentration of 1×10^-5 mol/L (P < 0.05). TSA increased the expression of Wnt3/3a, β-catenin and Ngn1. Conclusion TSA could promote NSCs differentiating into neurons in vitro, which may associate with the activation of the Wnt/β-catenin signaling pathway and the expression of differentiation-promoting target protein Ngn1. TSA can do it best in the concentration about 1×10^-5 mol/L..

Key words: total saponins of Astragalus, neural stem cells, differentiation, Wnt/β-catenin signaling pathway;, rats