OBJECTIVETo study the mechanism of reversal effect of Curcuma Wenyujin n-Butyl alcohol extract (CWNAE) on multiple drugs resistance (MDR) of SGC7901/VCR cells.

METHODSSGC7901/VCR cells were co-culured with different concentrations CWNAE (80, 40, and 20 μg/mL) and Verapamil (VP, 10 μg/mL) for 24 h, and then acted with Adriamycin (ADM) for 1, 2, and 4 h, respec- tively. SGC7901/VCR cells with no intervention were taken as the vehicle control group. SGC7901/VCR cells treated with ADM alone were taken as the control group. The effect of CWNAE on intracellular ADM concentration was detected by flow cytometry (FCM). Cells were treated as mentioned before without any intervention of ADM. SGC7901/VCR with no ADM intervention were taken as the control group. The effect of CWNAE on the expression of P-glycoprotein (P-gp), lung resistance protein (LRP), and glu- cosylceramide synthase (GCS) was studied by Western blot. The effect of CWNAE on the location and expression quantity of P-gp was further illustrated by immunohistochemistry (IHC).

RESULTSCompared with the ADM group, the expression ratio obviously increased in the W80, W40, W20, and VP10 groups with statistical difference (all P < 0.05). The comparative expression quantity of P-gp, GCS, and LRP in SGC7901/VCR cells was obviously higher than that of non-MDR with statistical difference (all P < 0.05). The expression quantity of P-gp and GCS could be obviously down-regulated by 80 and 40 μg/mL CWN- AE, and 10 μg/mL VP, with no effect on the expression of LRP. Results of IHC proved that P-gp was mainly expressed on the cytomembrane or in the plasma, and it was also expressed on the nuclear membrane. P-gp in different locations could all be down-regulated by CWNAE.

CONCLUSIONSCWNAE could reverse the MDR of SGC7901/VCR cell line probably by inhibiting the expression of P-gp and GCS. CWNAE had no effect on LRP that also highly expressed on SGC7901/VCR. So we supposed that CWNAE could become a potential drug to reverse MDR of highly expressed P-gp and GCS.