Table 1.
Antiproliferative activity (IC50) of colchicine (1) and its derivatives (2–8) compared with antiproliferative activity of standard anticancer drugs doxorubicin and cisplatin and the calculated values of the resistance index (RI) and selectivity index (SI) of tested compounds [19,39].
| Compound | A549 | MCF-7 | LoVo | LoVo/DX | BALB/3T3 | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| IC50 (μM) | SI | IC50 (μM) | SI | IC50 (μM) | SI | IC50 (μM) | SI | RI | IC50 (μM) | |
| 1 | 0.149 ± 0.009 | 1.4 | 0.128 ± 0.135 | 1.6 | 0.108 ± 0.025 | 1.9 | 2.65 ± 0.96 | 0.1 | 24.5 | 0.208 ± 0.042 |
| 2 | 0.011 ± 0.001 | 10.1 | 0.010 ± 0.002 | 11.9 | 0.021 ± 0.006 | 5.5 | 0.398 ± 0.075 | 0.3 | 19.0 | 0.114 ± 0.072 |
| 3 | 0.046 ± 0.035 | 3.0 | 0.023 ± 0.005 | 6.0 | 0.069 ± 0.012 | 2.0 | 0.784 ± 0.28 | 0.2 | 11.4 | 0.138 ± 0.069 |
| 4 | 0.022 ± 0.002 | 1.0 | 0.022 ± 0.002 | 1.0 | 0.022 ± 0.002 | 1.0 | 0.111 ± 0.044 | 0.2 | 5.1 | 0.022 ± 0.002 |
| 5 | 0.105 ± 0.008 | 1.4 | 0.027 ± 0.008 | 5.3 | 0.084 ± 0.021 | 1.7 | 1.55 ± 0.17 | 0.1 | 18.5 | 0.142 ± 0.073 |
| 6 | 0.010 ± 0.0001 | 10.3 | 0.015 ± 0.002 | 6.9 | 0.014 ± 0.004 | 7.4 | 0.135 ± 0.012 | 0.8 | 9.6 | 0.103 ± 0.089 |
| 7 | 0.094 ± 0.006 | 1.4 | 0.098 ± 0.029 | 1.4 | 0.010 ± 0.002 | 13.5 | 2.78 ± 0.45 | 0.1 | 278.0 | 0.135 ± 0.056 |
| 8 | 0.011 ± 0.002 | 10.5 | 0.017 ± 0.006 | 6.8 | 0.007 ± 0.002 | 16.4 | 0.642 ± 0.084 | 0.2 | 91.7 | 0.115 ± 0.044 |
| Doxorubicin | 0.258 ± 0.044 | 0.6 | 0.386 ± 0.118 | 0.4 | 0.092 ± 0.018 | 1.8 | 4.75 ± 0.99 | <0.1 | 51.6 | 0.166 ± 0.074 |
| Cisplatin | 6.367 ± 1.413 | 0.6 | 10.70 ± 0.753 | 0.4 | 4.37 ± 0.73 | 0.9 | 5.70 ± 0.63 | 0.7 | 1.3 | 3.90 ± 1.50 |
The IC50 value is defined as the concentration of a compound at which 50% growth inhibition is observed. Human lung adenocarcinoma (A549), human breast adenocarcinoma (MCF-7), human colon adenocarcinoma cell line (LoVo) and doxorubicin-resistant subline (LoVo/DX), normal murine embryonic fibroblast cell line (BALB/3T3). The SI (Selectivity Index) was calculated for each compound using the formula: SI = IC50 for normal cell line BALB/3T3/IC50 for respective cancerous cell line. A beneficial SI > 1.0 indicates a drug with efficacy against tumor cells greater than the toxicity against normal cells. The RI (Resistance Index) indicates how many times a resistant subline is chemoresistant relative to its parental cell line. The RI was calculated for each compound using the formula: RI = IC50 for LoVo/DX/IC50 for LoVo cell line. When RI is 0–2, the cells are sensitive to the compound tested, RI in the range 2–10 means that the cell shows moderate sensitivity to the drug tested, RI above 10 indicates strong drug resistance.