Table 4.
Effect of BSO, MK-571 and verapamil on the antiproliferative activities of bestatin and actinonina
| Drug efflux modifier (M) | % of inhibition of cell proliferation |
|||
|---|---|---|---|---|
| MK-571 (10 μM) | MK-571 (30 μM) | BSO (25 μM) | Verapamil (30 μM) | |
| U937+bestatin | 71.0±8.6 | n.d. | 39.8±5.0 | n.d. |
| U937+bestatin+M | 87.4±4.1 | 53.4±4.8 | ||
| P<0.001 | P<0.05 | |||
| U937+actinonin | 69.3±5.1 | n.d. | 32.3±24.3 | n.d. |
| U937+actinonin+M | 82.1±3.4 | 48.4±25.7 | ||
| P<0.0005 | P<0.005 | |||
| K562+bestatin | 47.0±5.4 | 47.0±5.4 | 19.6±16.0 | 44.3±13.5 |
| K562+bestatin+M | 66.0±3.7 | 73.6±3.4 | 41.5±17.0 | 70.5±5.7 |
| P<0.0001 | P<0.0001 | P<0.05 | P<0.005 | |
| K562+actinonin | 76.5±4.2 | 76.5±4.2 | 55.4±7.8 | 71.0±4.2 |
| K562+actinonin+M | 76.7±2.5 | 86.9±3.3 | 77.9±17.5 | 78.0±6.6 |
| P<0.0005 | P<0.05 | P>0.1 | ||
a
The final concentrations of inhibitors in cell cultures were 145 μM bestatin and 13 μM actinonin in the experiment with U937 cells, and 580 μM bestatin and 26 μM actinonin in the experiment with K562 cells. The antiproliferative effect of BSO, MK-571 and verapamil at the concentrations used were not statistically significant (P>0.05). The measurements were made on the 4th day after the addition of drug efflux modifier. Results are the average of two experiments each performed in quadruplicate. Results were analyzed by paired t-test.