Abstract: Objective: To explore the inhibitory effect of scutellarin(SCU) on the proliferation of human glioma U87 cells,and to clarify its mechanism. Methods: The U87 cells were cultured and divided into blank control group and 20,40,80 mg·L^-1 SCU groups,the surival rates of U87 cells in various groups were examined by MTT assay; the morphology of U87 cells in various groups were observed by inverted microscope;the apoptotic rates of U87 cells were examined by Annexin Ⅴ/PI staining; the expression levels of bax and bcl-2 proteins in the U87 cells in various groups were detected by Western blotting method. Results: The MTT results showed that compared with blank control group,the survival rates of U87 cells in 20,40,and 80 mg·L^-1 SCU groups were decreased(P<0.01).The inverted microscope observation results showed that compared with blank control group,the number of U87 cells in 80 mg·L^-1 SCU group was significantly decreased,and the cell volume was smaller;the U87 cells were shrinkage,shedding,and the outline of adherent cells was fuzzy.The results of AnnexinⅤ/PI staining showed that the late and total apoptotic rates of U87 cells in 80 mg·L^-1 SCU group were increased compared with blank control group (P<0.01).The Western blotting results showed that compared with blank control group,the expression levels of bcl-2 protein in the U87 cells in 20,40 and 80 mg·L^-1 SCU groups were decreased,especially in 80 mg·L^-1 SCU group(P<0.01).Compared with blank control group,the ratio of bax/bcl-2 in the U87 cells in 80 mg·L^-1 SCU group was significantly increased(P<0.01). Conclusion: SCU can induce the apoptosis and suppress the tumor growth by upregulating the bax/bcl-2 ratio in the U87 cells.

Key words: bcl-2, cell proliferation, apoptosis, scutellarin, glioma, bax