title: Saxifragifolin B from Androsace umbellata induced apoptosis on human hepatoma cells.
abstract: Bioassay-guided phytochemical study of Androsace umbellata led to the successful isolation of saxifragifolin B (SB) for the first time. The anti-tumor effect of SB was firstly reported that it was shown to have potent cytotoxicity on human hepatoma HepG2 cells with IC50 value of 11.9 microM at 24 h. Mechanistic studies were conducted, the accumulation of sub-G1 population and the externalization of phosphatidylserine suggested that SB exerted its cytotoxic effect by induction of programmed cell death, which was confirmed by activation of PARP and caspase-3. Furthermore, SB-induced apoptosis on HepG2 cells was mediated by activation of caspase-8 and -9, mitochondrial membrane potential (Deltapsim) collapse and the leakage of cytochrome c. In summary, this study provided evidence that SB isolated from A. umbellata could induce apoptosis on human hepatoma HepG2 cells and described the molecular mechanism. Our finding revealed the potential of SB as new chemotherapeutic agent for human hepatoma.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Room 603, Mong Man Wai Building, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Ming-Kuen
authors.initials: MK
authors.lastname: Tang
authors.forename: Yuet-Wa
authors.initials: YW
authors.lastname: Chan
authors.forename: Hung-Ming
authors.initials: HM
authors.lastname: Lam
authors.forename: Wen-Cai
authors.initials: WC
authors.lastname: Ye
authors.forename: Kwok-Pui
authors.initials: KP
authors.lastname: Fung
mesh_terms: D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004305:Dose-Response Relationship, Drug; D006801:Humans; D020128:Inhibitory Concentration 50; D053078:Membrane Potential, Mitochondrial; D008564:Membrane Potentials; D008968:Molecular Conformation; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010944:Plants / Q000378:metabolism*; D012503:Saponins / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D012503:Saponins; C523878:saxifragifolin B; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9