Table 1.
IC50 values at 24 h for cell growth inhibition in HT-29 and HCT 15 human colon cancer cell lines.
| Origin/Cell line, IC50 (nM) |
||
|---|---|---|
| Compound | Colon, HT-29 | Colon, HCT 15 |
| Aspirin | >5,000,000 | >5,000,000 |
| o-NOSH-aspirin | 40±11 | 62±6 |
| Enhanced potency | >125,000 | >80,000 |
| m-NOSH-aspirin | 240±110 | 92±4 |
| Enhanced potency | >20,000 | >50,000 |
| p-NOSH-aspirin | 460±170 | 370±40 |
| Enhanced potency | >10,000 | >13,000 |
HT-29 (COX-1/ -2 positive) and HCT 15 (COX null) human colon cancer cell lines were treated with various concentrations of the positional isomers of NOSH-ASA as described under Section 2.3. Cell numbers were determined at 24 h from which IC50 values were calculated. Results are mean±S.E.M. of five different experiments done in triplicate. For HT-29 cells, significance between the treatment groups were: o vs m, P>0.05; o vs p, P<0.05; m vs p, P>0.05. For HCT 15 cells, significance between the treatment groups were: o vs m, P<0.01; o vs p, P<0.001; m vs p, P<0.001.