P-glycoprotein (P-gp) and glutathione-S-transferase (GST) are key players in multidrug resistance (MDR).Inhibition of the expression of P-gp and/or GST has emerged as a promising therapeutic strategy for the reversal of MDR.Coniferyl ferulate (CF),isolated from Radix Angelicae sinensis (RAS),strongly inhibited human placental GST.Its 50% inhibition concentration (IC50) was 0.3 μM,which is greater than an known GST pl-1 inhibitor,ethacrynic acid (EA),using the established HTS model.