Sialic acid associated with oxidative stress and total antioxidant capacity (TAC) expression level as a predictive indicator in moderate to severe Alzheimer's disease.

Abstract

Several studies have shown many risk factors associated with disease onset, but the sialic acid association with oxidative stress biomarkers may a key factor in the pathogenesis of Alzheimer's disease (AD). We aim to find out the most specific biomarker from the peripheral blood samples in moderate to severe Alzheimer's patients. This study examined the level of sialic acid associated with oxidative stress biomarkers and total antioxidant capacity level (TAC) in the plasma samples. Different parameters of Oxidative stress and Total antioxidant capacity by the immunoassay method have been examined in AD patients as compared to controls. The Catalase (CAT), Superoxide dismutase (SOD), Lipid peroxidation (LPO), Glutathione peroxidase (GPx), Total Glutathione (GSH), and Protein carbonyl group levels were estimated in this study. Increased level of sialic acid is found associated with a higher level of reactive oxygen species parameters in the patients. The antioxidant parameter levels have been found significantly lower in AD, while Protein carbonyl group and lipid peroxidation were increased in cases as compared to controls with the area under the curve (AUC) 0.816, p<0.0001 and 0.754, p<0.0001. The Protein carbonyl group, Total antioxidant capacity (TAC), and Sigma-Aldrich TAC levels were higher in females as compared to males in AD patients. During AD pathology, sialic acid, protein carbonyl, and lipid peroxidation were found as the more sensitive marker that may be used as a diagnostic and prognostic biomarker.