Abstract: [Abstract]  Objective  To observe the role of baicalin on the expression of phosphorylated protein of signal transducers and activators of transcription signaling proteins (STATs) during the process that neural stem cells (NSCs) differentiating into neurons. Methods  NSCs were isolated from the embryonic cerebral cortex of the 14-15-day pregnant SD rats, which were cultured and passaged in vitro. The 3rd generation of NSCs was used in the experiment. NSCs were randomized into natural differentiation control group, three different doses of baicalin groups (7.5 μmol/L, 15 μmol/L and 30 μmol/L), leukemia inhibitory factor (LIF) + basic fibroblast growth factor (bFGF) group and baicalin + LIF + bFGF group. After 6 d culture in vitro, the immunohistochemical method was used to observe the expressions of microtubule-associated protein 2(MAP-2) and glial fibrillary acidic protein (GFAP) in different groups. The expression levels of phosphorylation protein of STAT3 in NSCs were detected by Western blotting method after 2 h and 6 d of culture. Results The expression of MAP-2 in NSCs was increased by baicalin, but the expression of GFAP in NSCs decreased. The expression of GFAP in NSCs was enhanced in LIF+bFGF group, which was inhibited by baicalin + LIF + bFGF. The phosphorylation level of STAT3 in NSCs was downregulated by baicalin, but the phosphorylation level of STAT3 was upregulated in LIF+ bFGF group. The upregulated phosphorylation level of STAT3 was inhibited in baicalin + LIF + bFGF group(P＜0.05). Conclusion   Baicalin can induce NSCs to differentiate into neurons, which may be caused by the downregulation of the phosphorylation level of STAT3 in NSCs.

Key words: Baicalin, signal transduction, transcription, genetic, transcription factors, leukemia, stem cell, 神经系统