title: Ethyl acetate extract of Chinese medicinal herb Sarcandra glabra induces growth inhibition on human leukemic HL-60 cells, associated with cell cycle arrest and up-regulation of pro-apoptotic Bax/Bcl-2 ratio.
abstract: Sarcandra glabra (Thunb.) Nakai, colloquially known as Caoshanhu, is a Chinese medicinal herb with reported anti-tumor, anti-inflammatory, anti-viral and non-specific immunoenhancing properties. Although the plant has been clinically used for treating a variety of diseases, its bioactive ingredients are largely unknown and its mode of action has never been investigated. In this study, the anti-tumor property of ethyl acetate (EA) extract of S. glabra was investigated by determining its in vitro growth-inhibitory effects on a panel of human cancer cell lines of different histotypes. Growth inhibition of the EA extract on the cancer cells seemed to be selective, and the leukemic HL-60 was found to be the most responsive after 48 h of treatment (IC50=58 microg/ml). Flow cytometric studies further illustrated that the extract might interfere with DNA replication and thus arrested the cell cycle at S phase in the leukemic cells, followed by DNA fragmentation and loss of phospholipid asymmetry in the plasma membrane after 72 h of treatment. Concurrently, the pro-apoptotic Bax/Bcl-2 ratio was also up-regulated by more than 178% of the control level. All these findings suggested that the extract had initiated apoptosis to kill the leukemic cells. Results from this pioneer study help to establish a scientific foundation for future research and development of the bioactive ingredients in EA extract of S. glabra as efficacious anti-cancer agents.
authors.affiliation: Department of Biology, The Chinese University of Hong Kong, Hong Kong, P.R. China.
authors.forename: W Y
authors.initials: WY
authors.lastname: Li
authors.forename: Lawrence C M
authors.initials: LC
authors.lastname: Chiu
authors.forename: W S
authors.initials: WS
authors.lastname: Lam
authors.forename: W Y
authors.initials: WY
authors.lastname: Wong
authors.forename: Y T
authors.initials: YT
authors.lastname: Chan
authors.forename: Y P
authors.initials: YP
authors.lastname: Ho
authors.forename: Elaine Y L
authors.initials: EY
authors.lastname: Wong
authors.forename: Y S
authors.initials: YS
authors.lastname: Wong
authors.forename: Vincent E C
authors.initials: VE
authors.lastname: Ooi
mesh_terms: D000085:Acetates / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D015820:Cadherins / Q000378:metabolism; D002453:Cell Cycle; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D018922:HL-60 Cells; D006801:Humans; D019684:Magnoliopsida / Q000378:metabolism*; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000188:drug therapy*; D010936:Plant Extracts / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D013997:Time Factors; D015854:Up-Regulation; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D000085:Acetates; D000970:Antineoplastic Agents; D015820:Cadherins; D010936:Plant Extracts; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C007650:ethyl acetate