Despite NAC pretreatment had improved some markers of antioxidant and anti-inflammatory, negative effects were observed such as: (1) shortening of the colon, similar to that found by Kim et al. [31], studying GPx1−/− × Cat−/− mice fed with 400 μL of NAC (40 nM) before (3 days) and during (4 days) colitis induction by DSS (3% w/v); (2) membrane damage in all organs studied (identified by MDA levels); (3) hyperglycemia; and (4) a decreased in anti-inflammatory power, discouraging the long-term use of this supplement. Here, CAT is linked to colitis.