TABLE 4

 Combination index (CI) analysis of the cytotoxicity of noscapine derivatives coadministered with vinblastine with in drug-sensitive and -resistant breast cancer cell lines

CI values were determined for the effects of coadministration of vinblastine and noscapine derivatives on cell proliferation. Complete dose-response relationships were determined for vinblastine in the absence or presence of the indicated concentrations of noscapine, (6) and (8). All values (mean ± S.E.M.) were obtained from three independent observations.

CompoundConcCombination Index
MCF7NCI/AdrRES
μM
Noscapine100.69 ± 0.02**1.13 ± 0.362
200.26 ± 0.05**0.11 ± 0.02*
300.33 ± 0.08**0.19 ± 0.06*
(6)0.11.64 ± 0.331.10 ± 0.35
0.31.04 ± 0.460.49 ± 0.25
11.11 ± 0.350.33 ± 0.15*
30.59 ± 0.02**0.24 ± 0.04**
(8)0.12.57 ± 1.012.11 ± 0.89
0.30.62 ± 0.360.75 ± 0.22
1n.d.0.52 ± 0.27*
3n.d.n.d.
  • Conc., concentration; MCF, human breast adenocarcinoma cell line; n.d., no values were determined.

  • * P < 0.05; **P < 0.01 indicate a statistically significant difference from the isobole, which is defined with CI = 1.