[Reversal of multidrug resistance of MCF-7/ADR in nude mice by grape seed polyphenol].

Objective: To study the reversing effect of Grape seed polyphenol (GSP) on multidrug resistance of MCF-7/ADR cell in vivo.

Methods: The transplantable breast carcinoma cell line MCF-7/ADR model was established in BALB/C-nu/nu mice by subcutaneous implantation. Flow cytometry (FCM) was used to investigate the changes of Pgp expression and apoptosis rate after different drug treatment.

Results: GSP has some effect on inhibition of tumor growth (the rate of inhibition was 18.35%), and combined with adriamycin can significantly inhibit tumor growth in nude mice, 20 mg/kg GSP can effectively reverse the resistance of MCF-7/ADR cells to ADR in vivo, and the rate of inhibition was 54.64%. FCM results showed that the expression of Pgp was significantly decreased (32.03 +/- 2.09) After administration of GSP and ADR, there was distinct difference between it and control (55.13 +/- 2.12). The mean rate of apoptosis was 15.12% +/- 1.04%, and was significantly increased compared with control (9.07% +/- 0.43%), P < 0.05.

Conclusion: GSP can effectively reversed the resistance of MCF-7/ADR cells in nude mice, the mechanism may be correlated with inhibition of Pgp expression and apoptosis.