Table 3. Multidrug resistance of Malformin C and reversal effects of Verapamil.
| IC50 (μM) | Folds of KB | ||||
|---|---|---|---|---|---|
| Drug/Compound | KB | KB-MDR | KB-MDR (+VRP) | KB-MDR | (+VRP) |
| Malformin C | 0.18±0.05 | 42±5 | 0.76±0.053 | 233 | 4 |
| Taxol | 0.048±0.007 | 3.0±0.3 | 0.20±0.013 | 63 | 4 |
| Doxarubicin | 0.012±0.002 | 0.56±0.1 | 0.033±0.012 | 47 | 3 |
Note: Values were means ± SD from more than three independent experiments, with each data point done in duplicate, and all the cells were exposed to different drugs for 72 hours. Verapamil (VRP) was added to the media at a concentration of 5 μM. VRP’s IC50 of KB cells were 34±1 μM, and no toxicity was observed at 5 μM.