Effects of Saikosaponin D on apoptosis in human U87 glioblastoma cells.

Saikosaponin D (SSd) is a type of Saponin derivative, which is a component extracted from Bupleurum falactum. SSd has been reported to exert anticancer activities. However, the effects of SSd on gliomas have not been elucidated. The aim of the present study was to investigate the pharmacological functions and potential molecular mechanisms of SSd in human U87 glioblastoma cells. The cells were treated with SSd at various concentrations for 48 h, the cell viability was assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assay, and the activation of Akt, extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK) and caspase-3 was assessed by western blotting. In addition, apoptosis levels were analyzed with Hoechst 33258 and Annexin V staining. The results demonstrated that treatment of the U87 glioma cells with SSd markedly suppressed cell proliferation in a dose-dependent manner. Meanwhile, SSd treatment enhanced apoptosis in the U87 cells. Furthermore, SSd significantly inhibited the phosphorylation of Akt and ERK, and promoted phosphorylated-JNK and cleaved caspase-3 expression. The present study revealed the potential therapeutic effects of SSd in the treatment of gliomas, and the cytotoxic effects of SSd in U87 cells were at least partly attributed to the depression of phosphatidylinositol 3-kinase/Akt and ERK protein expression levels, and activation of JNK and caspase-3 expression.