Calotropis gigantea extract induces apoptosis through extrinsic/intrinsic pathways and reactive oxygen species generation in A549 and NCI-H1299 non-small cell lung cancer cells

Jiyon Lee,Hyung Won Ryu,Do-Young Yoon,Hui-Ju Jang,Hang Jin,Jong-Woon Shin,Yesol Bak,Hyunwoo Chun,Sei Ryang Oh,Thu-Huyen Pham,Yong-In Kim

doi:10.1186/s12906-019-2561-1

Abstract

BackgroundCalotropis gigantea (CG) is a tall and waxy flower that is used as a traditional remedy for fever, indigestion, rheumatism, leprosy, and leukoderma. However, the precise mechanisms of its anticancer effects have not yet been examined in human non-small cell lung cancer (NSCLC) cells. In this study, we investigated whether CG extract exerted an apoptotic effect in A549 and NCI-H1299 NSCLC cells.MethodsThe ethanol extract of CG was prepared, and its apoptotic effects on A549 and NCI-H1299 NSCLC cells were assessed by using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining, cell cycle analysis, real-time polymerase chain reaction (RT-PCR), western blotting, JC-1 staining, and ROS detection assay.ResultsThe CG extract induced apoptosis through the stimulation of intrinsic and extrinsic signaling pathways in A549 and NCI-H1299 lung cancer cells. Cell cycle arrest was induced by the CG extract in both cell lines. Reactive oxygen species (ROS), which can induce cell death, were also generated in the CG-treated A549 and NCI-H1299 cells.ConclusionsThese data confirmed that CG caused apoptosis through the activation of extrinsic and intrinsic pathways, cell cycle arrest, and ROS generation in A549 and NCI-H1299 lung cancer cells. Thus, CG can be suggested as a potential agent for lung cancer therapy.

Highlights

Calotropis gigantea (CG) is a tall and waxy flower that is used as a traditional remedy for fever, indigestion, rheumatism, leprosy, and leukoderma
Various rutinosides were found in CG extract and isorhamnetin-3-O-rutinoside, one of the phytochemicals found in this experiment, has been reported to have anti-cancer effects [23]
The viability of A549 and NCI-H1299 cells decreased in a dose-dependent manner after CG treatment (Fig. 2b and c), but that of HaCaT human normal keratinocytes was not affected by CG (Fig. 2a), confirming that CG extract exerted cytotoxic effects in A549 and NCI-H1299 human non-small cell lung cancer (NSCLC) cells only

Summary

Introduction

Calotropis gigantea (CG) is a tall and waxy flower that is used as a traditional remedy for fever, indigestion, rheumatism, leprosy, and leukoderma. The precise mechanisms of its anticancer effects have not yet been examined in human non-small cell lung cancer (NSCLC) cells. Lee et al BMC Complementary and Alternative Medicine (2019) 19:134 major cause of apoptosis in lung cancer cells [7], as many factors, including p53, p27, p21, and cyclins, control the phases of the cell cycle. The extrinsic apoptotic pathway is triggered by the death receptor and ligand following the caspase-8 dependent signaling cascade. Both apoptotic pathways induce the inactivation of poly (ADP-ribose) polymerase (PARP), whose function is DNA damage repair [10], to destroy the cells [11]

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