Abstract: Objective:To investigate the effect of Schisandra chinensis polysaccharide (SCP) on the growth of brain tumor stem cells (BTSCs), and to clarify the mechanism of inhibiting the growth of BTSCs of SCP. Methods: The primary human glioma cells were cultured, then the BTSCs were isolated by CD133 immunomagnetic sorting. The neural stem cell surface markers CD133 and Nestin were detected by immunofluorescence assay. The proliferation rate of BTSCs was examined by MTT assay. Annexin Ⅴ-PI analysis was used to analyze the apoptotic rate of BTSCs. The expression levels of Bax, Bcl-2 and Caspase-3 proteins in BTSCs in various groups were detected by ELISA assay. Results: The results of immunofluorescence staining showed that the expressions of CD133 and Nestin were positive in BTSCs. Compared with control group, the proliferation rates of BTSCs in 200, 400 and 800 mg·L^-1 SCP groups were decreased, especially in 400 and 800 mg·L^-1 SCP groups (P<0.05). The results of Annexin Ⅴ-PI analysis showed that the apoptotic rate of BTSCs in 800 mg·L^-1 SCP group was increased compared with control group (P<0.05). The ELISA results showed that the expression levels of Bax in 200, 400 and 800 mg·L^-1 SCP groups were significantly increased (P<0.05), and the values of Bax/Bcl-2 were significantly increased (P<0.05); compared with control group, the Bcl-2 expression level in the BTSCs in 800 mg·L^-1 SCP group was decreased (P<0.05). The expression level of Caspase-3 protein in 800 mg·L^-1 SCP group was also significantly increased compared with control group (P<0.01). Conclusion: SCP could inhibit the growth of BTSCs,and the induction of apoptosis may be one of mechanisms.

Key words: Schisandra chinensis polysaccharides, apoptosis-related proteins, brain tumor stem cells, apoptosis