β-escin enhanced the sensitivity of cholangiocarcinoma cells to chemotherapeutic drugs. A: MDR cell line QBC939/5-FU cells were treated with different concentrations of 5-FU, CDDP, VCR, and MMC for 24 h. Cell viability measured by MTT assays; B-C: Effects of β-escin (20 μmol/L) in combination with chemotherapeutics (40 μmol/L) on QBC939 cells and QBC939/5-FU cells. Cell viability measured by MTT assays after treatment for 24 h. aP < 0.05 vs control. MDR: Multidrug resistance; MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide; 5-FU: 5-fluorouracil; VCR: Vincristine sulfate; MMC: Mitomycin C; CDDP: Cisplatin.