CAT and Alzheimer disease: Additionally, the increased MDA levels in AD rats were accompanied by decreased levels of all antioxidant markers: glutathione (GSH) (p < 0.0001), superoxide dismutase (SOD) (p < 0.0001), glutathione peroxidase (GPx) (p < 0.0001), and catalase (p < 0.0001) compared to the control group (G1).