Polyphyllin D, a steroidal saponin from Paris polyphylla, inhibits endothelial cell functions in vitro and angiogenesis in zebrafish embryos in vivo

Abstract

Ethnopharmacological relevance: Angiogenesis, the process of blood vessel formation, is critical to tumour growth. The importance of angiogenesis in tumour development has lead to the development of anti-angiogenic strategies to inhibit tumour growth. In this study, polyphyllin D (PD), an active component in Chinese herb, Paris polyphylla, was evaluated for its potential anti-angiogenic effects.

Materials and methods: The inhibitory effects of PD on three important processes involved in angiogenesis, i.e. proliferation, migration and differentiation were examined using human microvascular endothelial cell line HMEC-1 by MTT assay, scratch assay and tube formation assay, respectively. Using zebrafish embryos as an animal model of angiogenesis, the anti-angiogenic effect of PD was further verified in vivo.

Results: PD suppressed the growth of HMEC-1 cells at 0.1-0.4 μM without toxic effects. At 0.3 μM and 0.4 μM, PD significantly inhibited endothelial cell migration and capillary tube formation. About 70% of the zebrafish embryos showed defects in intersegmental vessel formation upon treatment with PD at concentrations of 0.156 μM and 0.313 μM.

Conclusion: The anti-angiogenic effects of PD have been explored in the study which implied a potential therapeutic development of PD in cancer treatment.