title: In vitro modulation of telomerase activity, telomere length and cell cycle in MKN45 cells by verbascoside.
abstract: Screening of natural products with anti-tumor activity as telomerase inhibitor is a new subject in the field of tumor therapy. Using telomerase PCR ELISA, telomere DNA hybridization and flow cytometry analysis, the effects of verbascoside, a phenylpropanoid glucoside extracted from Pedicularis striata Pall, on telomerase activity, telomere length and cell cycle of human gastric carcinoma cells MKN45 was examined in vitro. After being treated with a 50 % inhibition concentration of verbascoside (17.8 microg/ml), telomerase activity in the cells was significantly inhibited but not in the cellular supernatant, the average telomere length became remarkably short, and the sub-G0 /G1 peak and G2/M arrest were also displayed when compared to the control cells. These results suggest that verbascoside mediated-cell differentiation and apoptosis may be affected by telomere-telomerase-cell cycle dependent modulation. Thus, the antitumor mechanism of verbascoside is demonstrated once more by its inhibiting effect on telomerase activity in tumor cells, and the telomerase assay may provide a valuable screening method for antitumor activity of natural products.
authors.affiliation: Department of Chemistry, Lanzhou University, People's Republic of China.
authors.forename: Fangxin
authors.initials: F
authors.lastname: Zhang
authors.forename: Zhongjian
authors.initials: Z
authors.lastname: Jia
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Deng
authors.forename: Yaming
authors.initials: Y
authors.lastname: Wei
authors.forename: Rongliang
authors.initials: R
authors.lastname: Zheng
authors.forename: Lijing
authors.initials: L
authors.lastname: Yu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005960:Glucosides / Q000494:pharmacology*; D006801:Humans; D010636:Phenols / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D028083:Scrophulariaceae; D019098:Telomerase / Q000187:drug effects* / Q000378:metabolism; D016615:Telomere / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D059808:Polyphenols
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005960:Glucosides; D010636:Phenols; D010936:Plant Extracts; D019098:Telomerase; C058956:acteoside; D059808:Polyphenols