Polyphyllin D (PD), an active component from a traditional medicinal herb Paris polyphylla, which has long been used for the treatment of
cancer in Asian countries, has been found to hold significant antitumor activity in vivo or in vitro. However, there were few reports on the effects and underlying mechanism of PD on apoptosis in U87 human
glioma cells. The present study was conducted to evaluate apoptotic induction of PD in U87 human
glioma cells, and explore its underlying pathway. U87
glioma cells were cultured and treated with varied concentrations of PD (from 10(-8) to 10(-4) M). The inhibition of U87
glioma cell proliferation by PD was assessed by MTT assay. The apoptosis of U87
glioma cells was detected by flow cytometry, and western blot analysis was used to examine human
B-cell leukemia/
lymphoma 2 (Bcl-2), human Bcl-2 associated X
protein (Bax),
caspase-3, total-c-jun NH2-terminal
kinase (t-JNK), and phosphorylation-JNK (p-JNK)
protein expression in U87 human
glioma cells. The treatment with PD for 24 h significantly inhibited the proliferation of U87 human
glioma cells in a concentration-dependent manner. PD increased apoptosis and significantly upregulated the expression of Bax,
caspase-3, and p-JNK associated with apoptosis, but downregulated antiapoptotic Bcl-2 expression in U87 human
glioma cells. Our data provided evidences that PD induces apoptosis in U87 human
glioma cells. This effect might be associated with the JNK pathway.