Abstract
Vernonia zeylanica, is a shrub endemic to Sri Lanka. V. zeylanica has been used in Sri Lankan traditional medicine for the treatment of various diseases and conditions. The present study was designed to determine antiproliferative, apoptotic, autophagic, and antioxidant effects of vernolactone, isolated from V. zeylanica, in human embryonal carcinoma cells (NTERA-2, a cancer stem cell model). Antiproliferative effects of vernolactone in NTERA-2 cells and human peripheral blood mononuclear cells (control cells) were evaluated using the Sulforhodamine B (SRB) assay and WST-1 antiproliferative assays, respectively. The antiproliferative effect of vernolactone was further investigated using the colony formation assay. Effects of vernolactone on apoptosis were investigated by phase contrast light microscopic and fluorescence microscopic analysis, caspase 3/7 expression, and real-time PCR of apoptosis-associated genes p53 and Survivin. The effect of vernolactone on NTERA-2 cell migration was monitored using the wound healing assay. Effects of vernolactone on the expression of autophagy-related genes (LC3, Beclin 1, PI3K, Akt, and mTOR) were evaluated using real-time PCR. 2,2-Diphenyl-1-2,2-diphenyl-picrylhydrazyl (DPPH) radical scavenging assay, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays were also carried out to evaluate the antioxidant activity of vernolactone. Overall results confirm that vernolactone can exert antiproliferative effects, induce apoptosis and autophagy, and decrease NTERA-2 cell migration in a dose- and time-dependent manner with a very small antioxidant property.
Highlights
Despite the advances in cancer therapeutics, millions of people around the world are diagnosed with various types of cancer each year and half of the patients fail to survive [1]
Powdered Dulbecco’s modified Eagle medium, fetal bovine serum (FBS), streptomycin/penicillin, dimethyl sulfoxide (DMSO), agarose and trypsin/EDTA, DPPH (2,2-diphenyl-1-picryl hydrazyl), paclitaxel, ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6sulfonic acid) diammonium salt), aluminum chloride, trolox (6-hydroxy-2-5-7-8-tetramethylchroman-2-carboxylic acid), and Histopaque®-1077 were purchased from the SigmaAldrich Chemical Company, St
Human embryonal carcinoma (NTERA-2) cells were purchased from the American Type Culture Collection (ATCC), Manassas, VA, USA
Summary
Despite the advances in cancer therapeutics, millions of people around the world are diagnosed with various types of cancer each year and half of the patients fail to survive [1]. Irregularities in signaling pathways such as Wnt/β-catenin, Notch, and Hedgehog are common in CSCs, and these irregularities in signaling pathways provide a strong rationale to investigate new cancer stem cell therapeutics [6]. A recent study conducted in our laboratory demonstrated that combined chloroform and ethyl acetate extracts of V. zeylanica can induce antiproliferative effects in three breast cancer cell lines. This work leads to the isolation of vernolactone, a new sesquiterpene lactone, from V. zeylanica that has shown cytotoxic and apoptotic effects in three different breast cancer phenotypes through modulating heat shock proteins [12]. The undifferentiated, pluripotent embryonal carcinoma cells have been reported as the most convenient tool to investigate the fundamental molecular mechanisms of embryonic stem cells in vitro [14, 15]. NTERA-2 cl.D1 is a completely characterized highly pluripotent cancer stem cell line that has a close resemblance to human embryonic stem cells [16]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
