Objective: To study the effects of Siwu Mixture on reversing the multidrug resistance (MDR) of human erythrocyte leukemic cell line K562/ADM.
Method: With verapamil set as a positive control, MTT assay was applied to evaluate the resistant factor of cell line K562/ADM to anticancer drugs and the reversal index of Siwu Mixture on MDR of the cells. The concentration of adriamycin(ADM) in the cells was measured by reversal-phase high performance liquid chromatography. The immunofluorescence method was used to determine the expression of P-glucoprotein(Pgp) on cell membrane.
Result: When ADM was combined with Siwu Mixture, its concentration in the cells and the reversal index of MDR were significantly higher than those of blank control (P < 0.01). However, the expression of Pgp on cell membrane showed little difference ( P > 0.05).
Conclusion: In case of noncytotoxic dose, Siwu Mixture showed significant effect on reversing MDR of cell line K562/ADM. The effect might be related to decreasing efflux of anticancer drugs in the cells and increasing their concentration in the cells. Nevertheless, it had no influence on the expression of Pgp on cell membrane.