title: [Reversal effect and its mechanism of ampelopsin on multidrug resistance in K562/ADR cells].
abstract: OBJECTIVE
  To investigate the inhibitory effect of ampelopsin (AMP) combined with adriamycin (ADR) on growth of human leukemia multidrug resistant cell line K562/ADR.
  
  
  METHODS
  MTT assay was used to detect the effect of AMP on the cytotoxicity of ADR. Jin's formula was used to analyze the effect of combined drug therapy. The expression of P-glycoprotein (P-gp) on cell membrane of K562/ADR was detected using PE-labeled antibody. Flow cytometry was used to determine the influence of AMP on the intracellular accumulation of ADR.
  
  
  RESULTS
  AMP at the concentration of 1.25 to 5 mg x L(-1) could significantly reverse the multidrug resistance (MDR) to ADR in K562/ADR cells. Co-administration of 1.25 mg x L(-1) AMP and low concentrations of ADR showed an antagonistic effect, while there was an additional to synergistic effect when the concentration of AMP was above 2.5 mg x L(-1). AMP could decrease the expression of P-gp in a concentration-dependent manner and increase the intracellular accumulation of ADR in K562/ADR cells.
  
  
  CONCLUSIONS
  AMP could increased the cytotoxicity and the intracellular accumulation of chemotherapeutic drugs in MDR associated tumor cells through inhibiting the efflux of drugs by P-gp. AMP may be a promising MDR modulator.
authors.affiliation: School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510089, China.
authors.forename: Jiantao
authors.initials: J
authors.lastname: Ye
authors.forename: Yilei
authors.initials: Y
authors.lastname: Zheng
authors.forename: Deyu
authors.initials: D
authors.lastname: Liu
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004317:Doxorubicin / Q000378:metabolism / Q000494:pharmacology; D018432:Drug Resistance, Multiple / Q000187:drug effects*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D005419:Flavonoids; C106407:ampelopsin; D004317:Doxorubicin