Cognitive impairment and Alzheimer’s disease: Links with oxidative stress and cholesterol metabolism

Abstract

Abstract:Oxidative stress has been implicated in the progression of a number of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease and amyotrophic lateral sclerosis. We carried out an in-depth study of cognitive impairment and its relationships with oxidative stress markers such as ferric-reducing ability of plasma (FRAP), plasma malondialdehyde and total antioxidative capacity (TAC), as well as cholesterol parameters, in two subsets of subjects, AD patients (n = 59) and a control group of neurologically normal subjects (n = 29), attending the University Hospital Salvador in Santiago, Chile. Cognitive impairment was assessed by a set of neuropsychological tests (Mini-Mental State Examination, Boston Naming Test, Ideomotor Praxia by imitation, Semantic Verbal Fluency of animals or words with initial A, Test of Memory Alteration, Frontal Assessment Battery), while the levels of those oxidative stress markers and cholesterol metabolism parameters were determined according with standard bioassays in fresh plasma samples of the two subgroups of patients. No signifi cant differences were observed when the cholesterol parameters (low-, high-density lipoprotein, total cholesterol) of the AD group were compared with normal controls. Interestingly, a correlation was evidenced when the levels of cognitive impairment were analyzed with respect to the plasma antioxidant capacity (AOC) of patients. In this context, the subset of subjects exhibiting cognitive impairment were divided into two subgroups according with their Global Dementia Scale performance: a subgroup with mild AD and a subgroup with moderate to severe AD. Signifi cant differences in AOC were found between subgroups. The different correlations between cognitive impairment of subgroups of subjects with the oxidative stress profi le are discussed in the context of AD pathogenesis.

The Roles of Biomarkers of Oxidative Stress and Antioxidant in Alzheimer’s Disease: A Systematic Review

“…Several studies demonstrate that serum or plasma TBARS level in AD subjects is significantly higher than in controls [ 7 , 13 , 15 , 20 – 28 ], while others observe no significant difference between AD subjects and controls [ 29 – 35 ] ( Table 1 ). Results regarding erythrocyte TBARS level in AD are also controversial.…”

Protective Effects of Mangosteen Extract on H2O2-Induced Cytotoxicity in SK-N-SH Cells and Scopolamine-Induced Memory Impairment in Mice

“…High correlations between oxidative stress and cognitive impairment have been reported suggesting that oxidative stress should be considered as one of the risk factors in the development of cognitive disorders [ 24 ]. Since oxidative stress seems to be involved in the earliest phases of AD, the administration of antioxidants may be useful in the prevention and treatment of AD and other neurodegenerative disorders [ 25 ].…”

Telomere length and 8-hydroxy-2-deoxyguanosine as markers for early prediction of Alzheimer disease

“…Sekler et al . [ 26 ] assessed the plasma level of TAC in AD patients (mild, intermediate, and advanced disease) versus control groups. They found significantly lower TAC in AD patients (all stages) as compared to the control group.…”