Table 2. IC50a Values (μM) of Representative Compounds 16a–c in the Drug-Resistant and Parental Sensitive Cellsb.
| compd | SW620 | SW620/AD300 | NCI-H460 | NCI-H460/MX20 |
|---|---|---|---|---|
| oridonin | 6.26 ± 0.33 | 4.67 ± 0.17 | 17.14 ± 1.06 | 21.71 ± 0.98 |
| 16a | 13.95 ± 0.16 | 14.92 ± 1.28 | 28.41 ± 0.76 | >100 |
| 16b | 1.96 ± 0.11 | 1.86 ± 0.06 | 2.35 ± 0.14 | 2.91 ± 0.12 |
| 16c | 2.70 ± 0.07 | 2.28 ± 0.09 | 4.81 ± 0.11 | 7.26 ± 0.28 |
a
IC50: concentration that inhibits 50% of cell growth.
b
MTT cytotoxicity assay was assessed in pairs of parental and transporter-overexpressing cell lines: SW620 and ABCB1-overexpressing SW620/AD300 cells; NCI-H460 and ABCG2-overexpressing NCI-H460/MX20 cells.