Antineoplastic effects of deoxyelephantopin, a sesquiterpene lactone from Elephantopus scaber, on lung adenocarcinoma (A549) cells

Autor: Remani Prathapan, Mangalam S. Nair, Latha Panickaparambil Gopalakrishnan, Farha Arakkaveettil Kabeer, Dhanya S. Rajalekshmi, Geetha Balakrishnan Sreedevi, Sujathan Kunjuraman
Rok vydání: 2013
Předmět:
Zdroj: Journal of Integrative Medicine. 11:269-277
ISSN: 2095-4964
DOI: 10.3736/jintegrmed2013040
Popis: Objective Deoxyelephantopin, a sesquiterpene lactone from Elephantopus scaber , showed inhibition of the growth of various tumor cells in vitro. In the present study, we investigated the cytotoxicity and apoptosis-inducing capacity of deoxyelephantopin on lung adenocarcinoma (A549) cells. Methods The cytotoxic effect of deoxyelephantopin on A549 cells and normal lymphocytes was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 50% inhibitory concentration (IC 50 ) value was determined. The self-renewal and proliferating potential of A549 cells after treatment with deoxyelephantopin were examined by colony formation assay. Cellular morphology of deoxyelephantopin-treated cells was observed using phase-contrast microscopy. The induction of apoptosis was evaluated using acridine orange and ethidium bromide staining, Hoechst 33342 staining, terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end-labeling (TUNEL) assay, DNA fragmentation analysis and Annexin V-fluorescein isothiocyanate staining by flow cytometry. Activation of caspases was detected using fluorogenic substrate specific to caspases 2, 3, 8 and 9 and flow cytometric analysis. The total cellular DNA content and expression of cleaved poly (ADP-ribose) polymerase was also analyzed. Results Deoxyelephantopin exhibited cytotoxicity to A549 cells (IC 50 = 12.287 μg/mL), however, there was no toxicity towards normal human lymphocytes. Deoxyelephantopin suppressed the colony-forming ability of A549 cells in a dose-dependent manner. Acridine orange, ethidium bromide and Hoechst 33342 staining showed cell shrinkage, chromosomal condensation and nuclear fragmentation, indicating induction of apoptosis. Deoxyelephantopin increased apoptosis of A549 cells, as evidenced by more TUNEL-positive cells. DNA fragmentation and Annexin V staining revealed late-stage apoptotic cell population. Deoxyelephantopin inhibited A549 cell growth by cell cycle arrest at G 2 /M phase and induced apoptosis through both extrinsic and intrinsic pathways. Conclusion These results suggest that deoxyelephantopin has great potential as a new chemotherapeutic agent to be developed further for the treatment of lung cancer.
Databáze: OpenAIRE
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