Modulation of P-glycoprotein Activity by Flavonoids and Organic Isothiocyanates in Human Uterine Cells.

One of the possible mechanisms of multi-drug resistance found in cancer cells is the over-expression of P-glycoprotein (P-gp). Studies have shown that compounds found in plants including vegetables and fruits not only have anticancer activities but may also modulate P-gp activity. The effect of flavonoids and organic isothiocyanates on P-gp activity was studied in human uterine sarcoma cell lines, MES-Sa (sensitive) and MES-SD/DX5 (resistant). The accumulation of daunomycin (DNM), a P-gp substrate, was approximately 10 times greater in the sensitive cell as compared to the resistant cells over the entire time course (up to 2 hrs). (omitted)