Determination of the effect of berberine on epirubicin concentration in MCF-7 cells by LC-MS/MS: The mechanism of synergism explained by intracellular pharmacokinetics

This study investigated the inhibitory effect of epirubicin combined with berberine on MCF-7 cell proliferation and explored intracellular pharmacokinetics. A CCK-8 assay was used to detect the inhibitory effect of epirubicin alone and in combination with berberine on MCF-7 cell proliferation in vitro. A rapid and sensitive LC-MS/MS method was developed and validated to detect epirubicin in MCF-7 cells. After incubation with epirubicin and berberine at different time points, MCF-7 cells were lysed and precipitated by acetonitrile to extract the analyte. Chromatographic separation was performed on a C18 column. Daunorubicin was selected as the internal standard. The analytical method was applied to determine the epirubicin concentration in MCF-7 cells. Berberine was found to enhance the inhibitory effect of epirubicin (1 μg/mL and 2 μg/mL) on the proliferation of MCF-7 cells (P