Ethyl acetate extract from Selaginella doederleinii Hieron inhibits the growth of human lung cancer cells A549 via caspase-dependent apoptosis pathway.
BACKGROUND
Selaginella doederleinii Hieron has been used as a folk medicine for the treatment of different cancers, especially for nasopharyngeal carcinoma, lung cancer and trophoblastic tumor in China. Previously, the ethyl acetate extract from S. doederleinii (SDEA extract) showed favorable anti-cancer potentials. However, the main chemical composition and anticancer mechanism of the SDEA extract were still not very clear. Until now, there are no reports available about the oral toxicity of the extract.


OBJECTIVE
The present study was to further elucidate the chemical composition and anti-lung cancer mechanism of the SDEA extract, and evaluate the acute oral toxicity of the extract.


METHODS
The SDEA extract was separated and analysed by HPLC to disclose its main chemicals. The effects of the extract were then investigated in vitro on cell viability, apoptosis and cell cycle using fluorescence microscopy and flow cytometry, and the molecular mechanism against human lung cancer cells A549 was further studied by western blot assays. The in vivo anti-cancer effect of the extract was evaluated in A549 xenograft mice model by histochemical assay, and tumor growth, microvascular density (MVD) and Ki67 expression were also measured. In addition, acute oral toxicity test of the extract was executed in mice.


RESULTS
SDEA extract mainly contained eight biflavonoids. The extract caused the loss of mitochondrial membrane potential and induced cell apoptosis by upregulating Bax, downregulating Bcl-2, activating caspase-9 and caspase-3 and blocked the cell cycle in S phase. The extract reduced expression of antigen Ki67, decreased MVD, and significantly inhibited the tumor growth. The extract did not show apparent oral acute toxicity in healthy mice.


CONCLUSIONS
The SDEA extract exerted anti-tumor effect through activating mitochondrial pathways and reducing Ki67 expression and MVD. Low oral acute toxicity suggested it a promising chemotherapy agent.
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China; Provincial Clinical College of Fujian Medical University, Department of Pharmacy, Fuzhou 350001, China.
Yuxia
Y
Sui
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China.
Shaoguang
S
Li
Department of TCM resource and Apitherapy, Bee Science College, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Peiying
P
Shi
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China.
Youjia
Y
Wu
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China; Fujian Center For Disease Control & Prevention, Fuzhou 350001, China.
Yuxiang
Y
Li
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China.
Weiying
W
Chen
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China.
Liying
L
Huang
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China. Electronic address: yauhung@126.com.
Hong
H
Yao
Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350108, China. Electronic address: xhl1963@sina.com.
XinHua
X
Lin
D000072283:A549 Cells; D000085:Acetates / Q000737:chemistry*; D000284:Administration, Oral; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008175:Lung Neoplasms / Q000098:blood supply / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D008297:Male; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008856:Microscopy, Fluorescence; D055806:Microvessels / Q000187:drug effects / Q000473:pathology; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009389:Neovascularization, Pathologic; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D010946:Plants, Medicinal; D059807:S Phase Cell Cycle Checkpoints / Q000187:drug effects; D032503:Selaginellaceae / Q000737:chemistry*; D015398:Signal Transduction / Q000187:drug effects; D012997:Solvents / Q000737:chemistry*; D013997:Time Factors; D047368:Tumor Burden / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
D000085:Acetates; D000972:Antineoplastic Agents, Phytogenic; D019394:Ki-67 Antigen; D010936:Plant Extracts; D012997:Solvents; C007650:ethyl acetate; D020169:Caspases
A549; Apoptosis; Lung cancer; Mitochondrial apoptotic pathways; Selaginella doederleinii Hieron