Fig. 3.

Positional isomers of NOSH-aspirin inhibit proliferation and increase cell death. (A) For proliferation, HT-29 cells were treated with o-NOSH-ASA, m-NOSH-ASA and p-NOSH-ASA at the concentration corresponding to their IC₅₀s and 2×IC₅₀s for cell growth inhibition, for 24 h, compared to control. PCNA expression was determined by flow cytometry and expressed as percentage positive cells. Results are mean±SEM of three different experiments. *P<0.05, ^†P<0.01 compared with untreated cells. (B) Cells were treated with the positional isomers of NOSH-ASA at their respective IC₅₀ for cell growth inhibition and analyzed at different times for apoptosis by Annexin V- PI staining and flow cytometry. All the positional isomers of NOSH-aspirin induce apoptosis in a time-dependent manner. *P<0.05, ^†P<0.01 compared with untreated control cells.