Table 1.
Cytotoxicity of oridonin and doxorubicin toward sensitive and drug-resistant cancer cell lines and normal cells as determined by the resazurin reduction assay.
| Cell lines | Compounds, IC50 values in μM, and degree of resistancea (in bracket) |
||
|---|---|---|---|
| Oridonin | Doxorubicin | Resistance mechanism | |
| CCRF-CEM | 1.65 ± 0.14 | 0.24 ± 0.02 | |
| CEM/ADR5000 | 8.53 ± 0.77 (5.17) | 195.12 ± 14.30 (975.60) | P-gp |
| MDA-MB231 | 6.06 ± 0.71 | 1.10 ± 0.01 | |
| MDA-MB231/BCRP | 9.74 ± 1.04 (1.61) | 7.83 ± 0.01 (7.11) | BCRP |
| HCT116 (p53+/+) | 18.03 ± 1.61 | 1.43 ± 0.02 | |
| HCT116 (p53-/-) | 34.68 ± 2.98 (1.92) | 4.06 ± 0.04 (2.84) | p53 |
| U87MG | 17.37 ± 1.16 | 1.06 ± 0.03 | |
| U87MG.ΔEGFR | 15.34 ± 1.67 (0.88) | 6.11 ± 0.04 (5.76) | EGFR |
| AML12 | >109.76 | >73.59 | |
| HepG2 | 25.71 ± 2.11 (<0.23) | 1.41 ± 0.12 (<0.04) | Tumor versus normal cells |
Mean values ± SD of each three independent experiments with each six parallel measurements are shown. aThe degree of resistance was determined as the ratio of IC50 value of the resistant/IC50-sensitive cell line. N.a., not applicable.