Saponin from Tupistra chinensis Bak Inhibits NF-κB Signaling in Sarcoma S-180 Cell Mouse Xenografts.

This study examined the effect of saponins from Tupistra chinensis Bak (STCB) on the growth of sarcoma S-180 cells in vitro and in mouse xenografts as well as the underlying mechanisms. Cell proliferation was assessed by MTT assay. Cell cycle distribution was determined by flow cytometry. Sarcoma S-180 tumor-bearing mice were treated with different doses of STCB with 10 μg/mL 5-fluorouracil (5-Fu) as a positive control. The activity of nuclear factor (NF)-κB was detected by gel mobility shift assay. The mRNA level of NF-κB was determined by real-time quantitative RT-PCR. The results showed that in vitro STCB inhibited the growth of S-180 cells in a concentration-dependent manner, which was accompanied by cell cycle arrest at S-phase. In vivo STCB significantly inhibited the growth of S-180 tumor mouse xenografts in a dose-dependent manner with apparent induction of cell apoptosis. Moreover, STCB inhibited the activity of NF-κB p65 and reduced the expression of NF-κB p65 mRNA in mouse xenografts. It was concluded that STCB inhibits the proliferation and cell cycle progression of S-180 cells by suppressing NF-κB signaling in mouse xenografts. Our findings suggest STCB is a promising agent for the treatment of sarcoma.