Flavonoid-enriched extracts from Nelumbo nucifera leaves inhibits proliferation of breast cancer in vitro and in vivo

Aim of the studyThis study was aimed to investigate the antitumor effect of Nelumbo nucifera Leaf extract (NLE) on human MCF-7 cell line in vitro and in vivo.Materials and methodsQualitative analysis showed that NLE contained several compounds, including polyphenols, based on high-performance liquid chromatography (HPLC) analysis. We utilized flow cytometry, Western blot analysis, and immunoprecipitation assays to explore the inhibitory effect of NLE on MCF-7 human breast cancer cells. Furthermore, the tumoricidal effect of NLE was further measured using a xenograft nude mouse model.ResultsThe polyphenols identified in NLE consisted primarily of gallic acid, rutin, and quercetin. Cell-cycle analysis revealed that MCF-7 cells treated with NLE were arrested at the G0/G1 phase (approximately 86.54%). With western blotting, we found that treatment with NLE particularly induced p53 phosphorylation and p21 expression, and down-regulated expression of cyclins and cdks, which was responsible for the high protein expression of RB/E2F. Inactivation of fatty acid synthase (FAS) implied that FAS was a potent regulator as well of NLE-mediated anti-carcinogenesis. In our in vivo analysis, treatment with NLE (0.5 and 1%) effectively reduced tumor volume and tumor weight in mice inoculated with MCF-7 cells compared to the control samples.ConclusionsThese results confirmed that cell-cycle arrest was sufficient to elicit tumor regression following NLE treatment. Overall, our studies indicated that NLE has an antitumor activity and significant potential as a chemotherapeutic agent.