Nuciferine, extracted from Nelumbo nucifera Gaertn, inhibits tumor-promoting effect of nicotine involving Wnt/β-catenin signaling in non-small cell lung cancer.
J Ethnopharmacol. 2015 May 13 ;165:83-93. Epub 2015 Feb 16. PMID: 25698245
ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Nelumbo nucifera Gaertn are recorded in the earliest written documentation of traditional Chinese medicinal as"Ben Cao Gang Mu", a medicinal herb for blood clotting, dysentery and dizziness. Recently, nuciferine (NF), one of N. nucifera Gaertn leaf extracts has been shown to possess several pharmacological properties, including anti-viral and anti-cancer. The aim of this study is to investigate the underlying molecular mechanism of the anti-cancer activity of NF in NSCLC progression induced by nicotine
MATERIALS AND METHODS: The effect of NF on proliferation of A549 (human lung adenocarcinoma epithelial cell line) pretreated with or without nicotine was detected by tumor cell proliferation assay. TOP-Flash reporter assay was applied to investigate the activity of Wnt/β-catenin signaling in tumor cells in the presence of NF and/or nicotine. Apoptosis was measured using a FITC-Annexin V and PI detection kit by flow cytometry. In addition, mRNA or protein expression levels were respectively tested by quantitative RT-PCR or western blot. In vivo experiments, tumorsamples were fixed in formalin and embedded in paraffin for additional analyses by immunohistochemistry and TUNEL staining.
RESULTS: NF significantly inhibited the proliferation of NSCLC cells in the presence of nicotine, suppressed the activity of Wnt/β-catenin signaling, enhanced the stabilization of Axin, and induced apoptosis. NF down-regulated the expression levels of β-catenin and its downstream targets including c-myc, cyclin D and VEGF-A. NF also decreased the ratio of Bcl-2/Bax, which may explain the pro-apoptosis effect of NF. In tumorxenograft nude mice, NF not only inhibited the growth of non-small cell lung cancer (NSCLC) cells, but also remarkably alleviated the injury induced by nicotine in liver function.
CONCLUSIONS: NF has the remarkable effect to inhibit nicotine-induced NSCLC progression, which was due to its ability to reduce the activity of Wnt/β-catenin signaling. Thus, the work stated here emphasizes the importance of this traditional medicine and presents a potential novel alternative to NSCLC prevention and therapy.