title: Apigenin induces caspase-dependent apoptosis in human lung cancer A549 cells through Bax- and Bcl-2-triggered mitochondrial pathway.
abstract: The molecular mechanism and possible signaling pathway of apigenin-induced cytotoxicity and apoptosis in human lung cancer cells has not been reported. We investigated the role of ROS, Ca2+, caspases and Bax proteins and mitochondria membrane potential in apigenin-induced apoptosis in A549 cells. Cells were incubated with different concentrations of apigenin then cell morphological changes, DNA damage, cell viability and apoptosis were determined by Comet assay, and flow cytometric analysis. Sub-G1 phase was also examined. Western blot analysis was used to determined the levels of Bax and Bcl-2 and apoptosis associated proteins, and confocal laser microscope for examining the translocation of associated protein after exposed to apigenin. The results indicated that apigenin induced morphological changes, decreased percentage of viable cells and induced apoptosis dose- and time-dependently. DAPI staining and Comet assay also confirmed that apigenin-induced DNA condensation and damage. The levels of caspase-3, -8 and -9 involved in apigenin-induced apoptosis indicating caspase-dependent pathway was induced by apigenin. Western blotting showed that apigenin promoted cytochrome c levels and also induced dysfunction of mitochondria leading to the release of cytochrome c, AIF and Endo G, causing the activation of caspase-9 and -3, then apoptosis in A549 cells.
authors.affiliation: Department of Clinical Pathology, Cheng Hsin General Hospital, Taipei 112, Taiwan, R.O.C.
authors.forename: Hsu-Feng
authors.initials: HF
authors.lastname: Lu
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Chie
authors.forename: Ming-Sung
authors.initials: MS
authors.lastname: Yang
authors.forename: Ching-Sung
authors.initials: CS
authors.lastname: Lee
authors.forename: Jene-John
authors.initials: JJ
authors.lastname: Fu
authors.forename: Jai-Sing
authors.initials: JS
authors.lastname: Yang
authors.forename: Tzu-Wei
authors.initials: TW
authors.lastname: Tan
authors.forename: Shin-Hwar
authors.initials: SH
authors.lastname: Wu
authors.forename: Yi-Shih
authors.initials: YS
authors.lastname: Ma
authors.forename: Siu-Wan
authors.initials: SW
authors.lastname: Ip
authors.forename: Jing-Gung
authors.initials: JG
authors.lastname: Chung
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D047310:Apigenin / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D020169:Caspases / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002469:Cell Separation; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects; D005434:Flow Cytometry; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects*; D051028:bcl-2-Associated X Protein / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D047310:Apigenin; D020169:Caspases