CAT and Alzheimer disease: CAT enzyme activity (Figure 3D) was also increased in the AD group compared to HC (p ≤ 0.01) and Q50-treated groups (p ≤ 0.01), while the GSH concentration (Figure 3E) was lower compared to the HC, Q50, and AD + Qu25 groups (p ≤ 0.05; p ≤ 0.05; and p ≤ 0.001, respectively).