Résumé
<p><b>OBJECTIVE</b>To investigate the inhibitory effect of ampelopsin (AMP) combined with adriamycin (ADR) on growth of human leukemia multidrug resistant cell line K562/ADR.</p><p><b>METHOD</b>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.</p><p><b>RESULT</b>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.</p><p><b>CONCLUSION</b>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.</p>