The experimental periodontitis caused significant reduction of the GSH (Figure 6A), SOD (Figure 6B) and CAT (Figure 6C), as well as an increase on MDA (Figure 6D) gingival levels (P < 0.05) when compared to the Naïve group, suggesting that oxidative stress is observed in gingival tissue subjected to periodontitis. Here, CAT is linked to periodontitis.