p38 MAPK and ERK1/2 pathways are involved in the pro-apoptotic effect. of notoginsenoside Ft1 on human neuroblastoma SH-SY5Y cells

Aims: This study aims to investigate the effect and the mechanisms of notoginsenoside Ftl, a natural compound exclusively found in P. notoginseng, on the proliferation and apoptosis of human neuroblastoma SH-SY5Y cells. Main methods: CCK-8 assay was used to assess the cell proliferation. Flow cytometry was performed to measure the cell cycle distribution and cell apoptosis. Hoechst 33258 staining was conducted to confirm the morphological changes of apoptotic cells. Protein expression was detected by western blot analysis and caspase 3 activity was measured by colorimetric assay kit. Key findings: Among the saponins examined, Ft1 showed the best inhibitory effect on cell proliferation of SH-SY5Y cells with IC50 of 45 mu M. Ftl not only arrested the cell cycle at S. G(2)/M stages, but also promoted cell apoptosis, which was confirmed by Hoechst 33258 staining. Further studies demonstrated that Ft1 up-regulated the protein expressions of cleaved caspase 3, phospho-p53, p21, and cyclin BI, but down-regulated that of Bd-2. Moreover, Ft1 enhanced the phosphoiylation of ERK1/2, JNK and p38 MAPK. However, the phosphorylation ofJak2 and p85 PI3K was reduced by Ftlinhibitors of p38 MAPK and ERK1/2 but not JNK abrogated the up-regulated protein expressions of cleaved caspase 3, p21 and down-regulated protein expression of Bc1-2 as well as elevated caspase 3 activity induced by Ftl. Significance: EU arrested the proliferation and elicited the apoptosis of SH-SY5Y cells possibly via p38 MAPK and ERK1/2 pathways, which indicates the potential therapeutic effect of it on human neuroblastoma. (C) 2014 Elsevier Inc. All rights reserved.