RESUMEN
Objective: To investigate the reversal effect of astragaloside IV on multidrug resistance of MDA-MB-231/DOX in breast cancer cells. Methods: The cytotoxicity of astragaloside IV and sensitivity or drug resistance of breast cancer cells to doxorubicin (DOX) before and after treatment were determined by MTT assay. Liposome co-delivery system containing doxorubicin and astragaloside IV (LPs-DOX/AS) was constructed by ethanol injection-ammonium sulfate gradient method. The reversal effect of LPs-DOX/AS on multidrug resistance of breast cancer cells was determined by MTT method. The effect of LPs-DOX/AS on apoptosis was determined by flow cytometry. Results: Astragaloside IV had no significant cytotoxicity to breast cancer cells in the experimental concentration range. After combined with astragaloside IV, the IC50 values of DOX on MDA-MB-231 and MDA-MB-231/DOX cells decreased (P < 0.05), and the intervention effect on drug-resistant cells was more significant (P < 0.01). Compared with free DOX/AS-IV, the IC50 values of LPs-DOX/AS-IV on both breast cancer cells decreased (P < 0.05), and the effect on drug-resistant strains was more significant (P < 0.01). The apoptosis rate of drug-resistant strains treated with LPs-DOX/AS-IV was also significantly higher than that of free drug group (P < 0.05). Conclusion: Astragaloside IV has reversal effect on multidrug resistance of human breast cancer cell MDA-MB-231 to doxorubicin. The combination of astragaloside IV and doxorubicin and its liposome co-delivery system can effectively reverse or sensitize multidrug resistance in breast cancer.