Abstract:

Objective: To investigate the protective effects of schizandra B (Sch B)on the injury of human neuroblastoma SH-SY5Y cells induced by glutamic acid (Glu), and to clarify its influence in ATR signaling pathway.Methods: The SH-SY5Y cells were divided into control group,dimethyl sulfoxide(DMSO)group,model group,Sch B1 group,Sch B2 group,and Sch B3 group.The SH-SY5Y cells in control group were untreated; the SH-SY5Y cells in DMSO group were treated with DMSO (17 mmol·L^-1)for 24 h;the SH-SY5Y cells in model group were treated with Glu (20 mmol·L^-1)for 24 h. The SH-SY5Y cells in Sch B1 group,Sch B2 group,and Sch B3 group were firstly pretreated with Sch B (0.1 μmol·L^-1)for 24 h,and exposed to 20 mmol·L^-1 Glu for 24 h at the same time.The survival rate of SH-SY5Y cells was detected by MTT assay,and the changes of cell cycle of SH-SY5Y cells were determined by flow cytometry.Western blotting method was used to detect the protein expressions.Results: The MTT detection results showed that compared with model group,the survival rates of SH-SY5Y cells in Sch B1 group, Sch B2 group,and Sch B3 group were increased (P<0.05 or P<0.01),and the survival rate in Sch B2 group was the highest (P<0.01),the Sch B2 group was selected as Sch B group for the following experiment.The cell cycle detection results showed that the percentage of SH-SY5Y cells in model group at G₀/G₁ phage was decreased(P<0.05); compared with control group,the percentages of SH-SY5Y cells in model group at S phage and G₂/M phage were increased (P<0.05);compared with model group, the percentage of SH-SY5Y cells in Sch B group at G₀/G₁ phage was increased (P<0.05),and the percentages of SH-SY5Y cells in Sch B group at S phage and G₂/M phage were decreased (P<0.05). The Western blotting detection results showed that compared with control group,the expression levels of ATR,p-CHK1,p-Cdc25c and P53 proteins in the SH-SY5Y cells in model group were increased (P<0.05);compared with model group,the expression levels of ATR,p-CHK1,p-Cdc25c and P53 proteins in the SH-SY5Y cell in Sch B group were decreased (P<0.05). Conclusion: Sch B could protect the damage of SH-SY5Y cells by GLu,and its mechanism may be related to inhibiting the ATR signaling pathway and reducing the cell cycle arrest.

Key words: schizandra B, ATR signaling pathway, SH-SY5Y cell, glutamic