Figure 5.

Effect of oxidative stress on cellular viability. (A) HT-29 and (B) HCT-116 cells were treated with varying concentrations of H₂O₂ for 24 h, and viability was measured using trypan blue staining. The relative fold changes in the viability was calculated considering control as 1 and compared with viability of cells at different H₂O₂ concentrations. Representative bright field images are provided for non-treated and 0.5 mM H₂O₂ treated cells. Similarity, the effect of antioxidant (NAC: 5 mM) on (C) HT-29 and (D) HCT-116 cell survival, with or without the H₂O₂ at given concentrations, was measured and compared with their non-treated control. Representative images indicate the recovery of cells after NAC treatment. Scale bar, 50 µm. **P<0.01 and ***P<0.001 vs. 0 mM H₂O₂/at indicated H₂O₂ concentrations without NAC. NAC, N-acetyl cysteine.