Stress In Alzheimer's Disease Research Articles

Hippocampal microvasculature changes in association with oxidative stress in Alzheimer's disease.

Vascular endothelial dysfunction is a primary phenotype of aging, and microvascular (MV) lesion is mainly associated with Alzheimer's disease (AD). Here we have studied the correlation of MV wall thickness and CA1 pyramidal neuronal pathology in autopsy-confirmed AD brains. Both hyaline (h-MV) and increased cell number (c-MV) associated MV wall thickening was found in age-matched control (AC) hippocampus without significant change in Aβ level (Braak stages 0-III). AC neurons neighboring the h-MV showed lower levels of oxidative DNA/RNA damage and Aβ precursor protein (APP), while the neurons around c-MV showed higher oxidative DNA/RNA damage with increased APP expression. Neurons in AC hippocampus without MV wall thickening (thin wall) showed increased DNA/RNA damage and APP levels compared to AC cases with h-MV and c-MV walls. In the AD hippocampus neurons neighboring h-MV walls showed increased levels of Aβ and decreased number of dendritic spines (at Braak stages IV-VI). C-MV neighboring neurons in the AD cases showed higher levels of DNA/RNA damage with increased APP at stages II - III, followed by lower levels of oxidative DNA/RNA damage, decreased APP and increased Aβ levels with loss of dendritic spines at stages IV-VI. Prolonged treatment of primary human fetal hippocampal neurons with tert-butyl hydroperoxide (TBHP) induced oxidative DNA damage with a sustained increase in APP. Aβ increased rapidly and then decreased overtime. Short-term TBHP treated neurons showed lower levels of superoxide (O2• -) without significant DNA damage. Short-term TBHP treatment induced a gradual decrease in APP but an increase in Aβ levels over time. In conclusion this study indicates that AD hippocampus at Braak stages II-III are characterized by strong oxidative DNA/RNA damage with increased APP in neurons associated with c-MV, while stages IV-VI are characterized by a slow increase in Aβ in neurons neighboring both h-MV and c-MV.

Salvianolic acid B attenuates mitochondrial stress against Aβ toxicity in primary cultured mouse neurons

Mitochondrial dysfunction is a featured pathology underlying synaptic injury and neuronal stress in Alzheimer's disease (AD). In recent years, the vicious cycle between mitochondrial deficits and intra-neuronal Redox state imbalance has received considerable attention. In this regard, it is of great interest to determine whether antioxidants could alleviate mitochondrial dysfunction in AD-related conditions. Salvianolic acid B (SalB), a bioactive component of alvia miltiorrhiza Bge, is a potent antioxidant. Here we have determined the protective effect of SalB against Aβ-induced mitochondrial abnormalities. Our results showed that the application of SalB substantially alleviated intra-neuronal glutathione (GSH) and lipid oxidation and suppressed excess mitochondrial superoxide generation in Aβ-insulted neurons. Moreover, SalB has demonstrated strong protection on mitochondrial bioenergetics against Aβ toxicity evidenced by preserved mitochondrial membrane potential and ATP production, as well as rescued enzymatic activities of cytochrome C oxidase and F1Fo ATP synthase. In addition, Aβ-induced axonal mitochondrial fragmentation and increased dynamin-like protein 1 phosphorylation at Ser 616 were substantially mitigated by SalB. Lastly, the application of SalB restored synaptic density in Aβ-exposed neurons. The most parsimonious interpretation of the results is that intra-neuronal oxidative stress promotes mitochondrial dysfunction in AD-relevant pathological settings, and SalB has the potential to be a promising agent for AD therapy.

Oxidative stress in Alzheimer disease as a target for therapy.

In the recent time, neurodegenerative disorders like Alzheimer disease were recognized for their significant role in the current healthcare because of their growing incidence and costs for health insurance systems. Effective therapy is missing and even etiology of the diseases like Alzheimer disease is not deeply known. In the case of Alzheimer disease, it is probable that oxidative stress is at least a factor involved in the disease. Nevertheless, the current literature is controversial and ambiguous in this matter. This review is focused on mapping the role of oxidative stress as well as on a consideration that oxidative stress represents the pathway at which a therapeutic strategy can be aimed. This paper provides a survey of contemporary literature on oxidative stress in Alzheimer disease and discusses the opportunities for establishing a therapy based on interfering the stress (Fig. 5, Ref. 117).

Minor Structural Variations of Small Molecules Tune Regulatory Activities toward Pathological Factors in Alzheimer's Disease.

Chemical tools have been valuable for establishing a better understanding of the relationships between metal ion dyshomeostasis, the abnormal aggregation and accumulation of amyloid-β (Aβ), and oxidative stress in Alzheimer's disease (AD). Still, very little information is available to correlate the structures of chemical tools with specific reactivities used to uncover such relationships. Recently, slight structural variations to the framework of a chemical tool were found to drastically determine the tool's reactivities toward multiple pathological facets to various extents. Herein, we report our rational design and characterization of a structural series to illustrate the extent to which the reactivities of small molecules vary toward different targets as a result of minor structural modifications. These compounds were rationally and systematically modified based on consideration of properties, including ionization potentials and metal binding, to afford their desired reactivities with metal-free or metal-bound Aβ, reactive oxygen species (ROS), and free organic radicals. Our results show that although small molecules are structurally similar, they can interact with multiple factors associated with AD pathogenesis and alleviate their reactivities to different degrees. Together, our studies demonstrate the rational structure-directed design that can be used to develop chemical tools capable of regulating individual or interrelated pathological features in AD.

Transplantation of rat bone marrow-derived mesenchymal stem cells regulates oxidative stress in Alzheimer’s disease transgenic mouse model

Background: It is widely recognized that increased oxidative damage on neurons is an early event in Alzheimer’s disease (AD). It has been reported that mesenchymal stem cells (MSC) can reduce oxidative stress on many kinds of disease. Our group have shown that the changes in redox status of the AD model mouse brain can be visualized noninvasively using three-dimensional electron paramagnetic resonance (EPR) imaging (Free Radic Biol Med. 2015).

Dietary Modulation of Oxidative Stress in Alzheimer's Disease.

Cells generate unpaired electrons, typically via oxygen- or nitrogen-based by-products during normal cellular respiration and under stressed situations. These pro-oxidant molecules are highly unstable and may oxidize surrounding cellular macromolecules. Under normal conditions, the reactive oxygen or nitrogen species can be beneficial to cell survival and function by destroying and degrading pathogens or antigens. However, excessive generation and accumulation of the reactive pro-oxidant species over time can damage proteins, lipids, carbohydrates, and nucleic acids. Over time, this oxidative stress can contribute to a range of aging-related degenerative diseases such as cancer, diabetes, macular degeneration, and Alzheimer’s, and Parkinson’s diseases. It is well accepted that natural compounds, including vitamins A, C, and E, β-carotene, and minerals found in fruits and vegetables are powerful anti-oxidants that offer health benefits against several different oxidative stress induced degenerative diseases, including Alzheimer’s disease (AD). There is increasing interest in developing anti-oxidative therapeutics to prevent AD. There are contradictory and inconsistent reports on the possible benefits of anti-oxidative supplements; however, fruits and vegetables enriched with multiple anti-oxidants (e.g., flavonoids and polyphenols) and minerals may be highly effective in attenuating the harmful effects of oxidative stress. As the physiological activation of either protective or destructive pro-oxidant behavior remains relatively unclear, it is not straightforward to relate the efficacy of dietary anti-oxidants in disease prevention. Here, we review oxidative stress mediated toxicity associated with AD and highlight the modulatory roles of natural dietary anti-oxidants in preventing AD.

Covalent modifications of the amyloid beta peptide by hydroxynonenal: Effects on metal ion binding by monomers and insights into the fibril topology

Amyloid β peptides (Aβ) and metal ions are associated with oxidative stress in Alzheimer's disease (AD). Oxidative stress, acting on ω-6 polyunsaturated fatty acyl chains, produces diverse products, including 4-hydroxy-2-nonenal (HNE), which can covalently modify the Aβ that helped to produce it. To examine possible feedback mechanisms involving Aβ, metal ions and HNE production, the effects of HNE modification and fibril formation on metal ion binding was investigated. Results indicate that copper(II) generally inhibits the modification of His side chains in Aβ by HNE, but that once modified, copper(II) still binds to Aβ with high affinity. Fibril formation protects only one of the three His residues in Aβ from HNE modification, and this protection is consistent with proposed models of fibril structure. These results provide insight into a network of biochemical reactions that may be operating as a consequence of oxidative stress in AD, or as part of the pathogenic process.

Initial bonding of ferric ion (Fe3+) and amyloid beta (Aß) peptide as the precondition for oxidative stress in Alzheimer's disease

Initial bonding of ferric ion (Fe3+) and amyloid beta (Aß) peptide as the precondition for oxidative stress in Alzheimer's disease

The Proteasome and Oxidative Stress in Alzheimer's Disease.

Alzheimer's disease is a neurodegenerative disorder that is projected to exceed more than 100 million cases worldwide by 2050. Aging is considered the primary risk factor for some 90% of Alzheimer's cases but a significant 10% of patients suffer from aggressive, early-onset forms of the disease. There is currently no effective Alzheimer's treatment and this, coupled with a growing aging population, highlights the necessity to understand the mechanism(s) of disease initiation and propagation. A major hallmark of Alzheimer's disease pathology is the accumulation of amyloid-β (Aβ) aggregates (an early marker of Alzheimer's disease), and neurofibrillary tangles, comprising the hyper-phosphorylated microtubule-associated protein Tau. Recent Advances: Protein oxidation is frequently invoked as a potential factor in the progression of Alzheimer's disease; however, whether it is a cause or a consequence of the pathology is still being debated. The Proteasome complex is a major regulator of intracellular protein quality control and an essential proteolytic enzyme for the processing of both Aβ and Tau. Recent studies have indicated that both protein oxidation and excessive phosphorylation may limit Proteasomal processing of Aβ and Tau in Alzheimer's disease. Thus, the Proteasome may be a key factor in understanding the development of Alzheimer's disease pathology; however, its significance is still very much under investigation. Discovering how the proteasome is affected, regulated, or dysregulated in Alzheimer's disease could be a valuable tool in the efforts to understand and, ultimately, eradicate the disease. Antioxid. Redox Signal. 25, 886-901.

Synthesis of Strophasterol A Guided by a Proposed Biosynthesis and Innate Reactivity.

The synthesis of strophasterol A, a moderator of endoplasmatic reticulum (ER) stress in Alzheimer's disease, and the first member of a structurally unprecedented class of secosterols, was achieved through the implementation of a key step of its proposed biosynthesis and two C-H oxidations. Analysis of the innate reactivity of the intermediates enabled the identification of a novel way to prepare an α-chloro-γ-hydroxy-δ-keto enone, as well as its vinylogous α-ketol rearrangement to a δ-keto carboxylic acid.

Copper complexes bearing 2-aminobenzothiazole derivatives as potential antioxidant: Synthesis, characterization

Novel copper complexes of Schiff base ligands of 2-aminobenzothiazole derivatives were synthesized by the condensation of Knoevenagel condensate of acetoacetanilide (obtained from substituted benzaldehydes and acetoacetanilide) and 2-aminobenzothiazole. They were characterized by elemental analysis, IR, 1H NMR, UV–Vis., molar conductance, magnetic susceptibility measurements and electrochemical studies. Based on the magnetic moment and electronic spectral data, square planar geometry has been suggested for all the complexes. Antibacterial and antifungal screening of the ligands and their complexes reveal that all the complexes show higher activities than the ligands. The binding behaviour of the complexes with calf thymus DNA has been investigated by electronic absorption spectra, viscosity measurements and cyclic voltammetry. The DNA binding constants reveal that all these complexes interact with DNA through intercalation binding mode. Superoxide dismutase and antioxidant activities of the copper complexes have also been studied. The antioxidant activities of the complexes showed higher activities. Thermal denaturation studies suggested the nature binding affinity of copper complexes with CT-DNA. All complexes exhibit suitable Cu(II)/Cu(I) redox potential to act as antioxidant enzymes mimic. Further, the copper complexes also showed catalase activity. It is hope that copper complexes were capable of decrease ROS levels or reduce oxidative stress in Alzheimer's patients.

Physiological Roles of Ubiquitin Ligases Related to the Endoplasmic Reticulum.

Studies on endoplasmic reticulum (ER)-associated degradation (ERAD), in which unfolded proteins accumulated in the ER are selectively transported to the cytosol for degradation by the ubiquitin-proteasome system, have been focused on molecular mechanisms in yeast. In human, disruption of the ER quality control system causes various diseases, such as neurodegenerative disease, lifestyle disease, and cancer. However, there are many ERAD genes with unknown physiological and pathological functions. We identified the novel ubiquitin ligase HRD1 involved in ERAD. HRD1 is expressed in brain neurons and protects against ER stress-induced apoptosis. In familial Parkinson's disease, accumulation of Parkin-associated endothelin receptor-like receptor (Pael-R), a substrate of ubiquitin ligase Parkin involved in ERAD, causes ER stress and apoptosis. We demonstrated that HRD1 promotes ubiquitination and degradation of Pael-R and suppresses ER stress and apoptosis induced by Pael-R. Amyloid precursor protein (APP) is processed into amyloid β (Aβ) in Alzheimer's disease. We found that HRD1 promotes APP ubiquitination and degradation, resulting in decreased generation of Aβ. Furthermore, suppression of HRD1 expression causes APP accumulation and Aβ generation associated with ER stress and apoptosis. Interestingly, HRD1 protein levels significantly decreased in the cerebral cortex of Alzheimer's disease patients, possibly because of its insolubilization. We demonstrated that HRD1 protein was insolubilized by oxidative stress, resulting in the accumulation of HRD1 into the aggresome. In conclusion, oxidative stress-induced HRD1 insolubilization might be involved in a vicious cycle of increased Aβ production and Aβ-induced oxidative stress in Alzheimer's disease pathogenesis.

Importance of the Dimethylamino Functionality on a Multifunctional Framework for Regulating Metals, Amyloid-β, and Oxidative Stress in Alzheimer's Disease.

The complex and multifaceted pathology of Alzheimer's disease (AD) continues to present a formidable challenge to the establishment of long-term treatment strategies. Multifunctional compounds able to modulate the reactivities of various pathological features, such as amyloid-β (Aβ) aggregation, metal ion dyshomeostasis, and oxidative stress, have emerged as a useful tactic. Recently, an incorporation approach to the rational design of multipurpose small molecules has been validated through the production of a multifunctional ligand (ML) as a potential chemical tool for AD. In order to further the development of more diverse and improved multifunctional reagents, essential pharmacophores must be identified. Herein, we report a series of aminoquinoline derivatives (AQ1-4, AQP1-4, and AQDA1-3) based on ML's framework, prepared to gain a structure-reactivity understanding of ML's multifunctionality in addition to tuning its metal binding affinity. Our structure-reactivity investigations have implicated the dimethylamino group as a key component for supplying the antiamyloidogenic characteristics of ML in both the absence and presence of metal ions. Two-dimensional NMR studies indicate that structural variations of ML could tune its interaction sites along the Aβ sequence. In addition, mass spectrometric analyses suggest that the ability of our aminoquinoline derivatives to regulate metal-induced Aβ aggregation may be influenced by their metal binding properties. Moreover, structural modifications to ML were also observed to noticeably change its metal binding affinities and metal-to-ligand stoichiometries that were shown to be linked to their antiamyloidogenic and antioxidant activities. Overall, our studies provide new insights into rational design strategies for multifunctional ligands directed at regulating metal ions, Aβ, and oxidative stress in AD and could advance the development of improved next-generation multifunctional reagents.

Role of oxidative stress in Alzheimer's disease.

Alzheimer's disease (AD) is the most common cause of disability in individuals aged >65 years worldwide. AD is characterized by the abnormal deposition of amyloid β (Aβ) peptide, and intracellular accumulation of neurofibrillary tangles of hyperphosphorylated τ protein and dementia. The neurotoxic oligomer Aβ peptide, which is the neuropathological diagnostic criterion of the disease, together with τ protein, are mediators of the neurodegeneration that is among the main causative factors. However, these phenomena are mainly initiated and enhanced by oxidative stress, a process referring to an imbalance between antioxidants and oxidants in favour of oxidants. This imbalance can occur as a result of increased free radicals or a decrease in antioxidant defense, free radicals being a species that contains one or more unpaired electrons in its outer shell. The major source of potent free radicals is the reduction of molecular oxygen in water, that initially yields the superoxide radical, which produces hydrogen peroxide by the addition of an electron. The reduction of hydrogen peroxide produces highly reactive hydroxyl radicals, termed reactive oxygen species (ROS) that can react with lipids, proteins, nucleic acids, and other molecules and may also alter their structures and functions. Thus, tissues and organs, particularly the brain, a vulnerable organ, are affected by ROS due to its composition. The brain is largely composed of easily oxidizable lipids while featuring a high oxygen consumption rate. The current review examined the role of oxidative stress in AD.

Mitochondria-Targeting Ceria Nanoparticles as Antioxidants for Alzheimer's Disease.

Mitochondrial oxidative stress is a key pathologic factor in neurodegenerative diseases, including Alzheimer's disease. Abnormal generation of reactive oxygen species (ROS), resulting from mitochondrial dysfunction, can lead to neuronal cell death. Ceria (CeO2) nanoparticles are known to function as strong and recyclable ROS scavengers by shuttling between Ce(3+) and Ce(4+) oxidation states. Consequently, targeting ceria nanoparticles selectively to mitochondria might be a promising therapeutic approach for neurodegenerative diseases. Here, we report the design and synthesis of triphenylphosphonium-conjugated ceria nanoparticles that localize to mitochondria and suppress neuronal death in a 5XFAD transgenic Alzheimer's disease mouse model. The triphenylphosphonium-conjugated ceria nanoparticles mitigate reactive gliosis and morphological mitochondria damage observed in these mice. Altogether, our data indicate that the triphenylphosphonium-conjugated ceria nanoparticles are a potential therapeutic candidate for mitochondrial oxidative stress in Alzheimer's disease.

Perceived caregiver stress in Alzheimer's disease and mild cognitive impairment: A case control study.

Objectives:Cross sectional studies have reported a tremendous amount of stress in caregivers of patients with Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). The present study aimed at evaluating the perceived stress in caregivers of patients with AD and MCI compared to controls.Materials and Methods:Caregivers of patients diagnosed with Alzheimer's disease/Mild Cognitive Impairment were recruited at the Memory Clinic of Neurology Department of a Tertiary Care Hospital in Northern India. The controls included caregivers of patients with chronic medical and psychiatric disorders. Caregivers were interviewed using Perceived Stress Scale (PSS) and the patients were assessed using The Blessed Activity of Daily Living (ADL), Mini Mental State Examination (MMSE) and Clinical Dementia Rating scale. The perceived stress of caregivers was compared amongst both groups and correlated with the severity of illness and activities of daily living of the patients.Results:Caregivers of a total of 31 patients of AD/MCI (Males = 24, Females = 7), and 30 controls (Males = 18, Females = 12) were interviewed. PSS Score was 23.29 ± 7.17 in cases and 7.5 ± 3.12 in controls. ADL Score was 7.97±5.53 in cases and 0.00 in controls. There was a significant difference between the PSS and ADL scores between those with AD and controls (P < 0.0001). Caregivers of patients with MCI had lower PSS scores compared to AD caregivers but significantly higher scores compared to caregivers of other chronic disorders. Similarly, correlation between Perceived Stress and ADL was significant (P < 0.001).Conclusions:Present study shows that caregivers of patients with AD/MCI have a high perceived stress compared to caregivers of patients with other chronic illness.

In vitro screening on amyloid beta modulation of aqueous extracts from plant seeds.

Introduction:Glycation process might contribute to both extensive protein cross-linking and oxidative stress in Alzheimer's disease (AD). The amyloid-like aggregation of glycated bovine serum albumin induces apoptosis in the neuronal cell. Dietary supplementation of antioxidants, vitamins, and polyphenols are beneficial to AD, and consumption of fruits and vegetables reduce the risk of AD. We conducted a screening of 14 aqueous extracts from plant seeds (PSAE) for inhibitory activity on amyloid beta (Aβ).Materials and Methods:To examine the effects of PSAE on the Aβ (1–42) concentration, PSAE were analyzed by Aβ (1–42) enzyme-linked immunosorbent assay. Furthermore, we carried out an antiglycation experiment of PSAE and an antiaggregation experiment of PSAE to confirm the modification mechanism of PSAE. PSAE were added to buffer containing D-ribose and albumins. The solutions were incubated at 37°C for 10 days. After incubation, the products were assayed on a fluorophotometer.Results:PSAE associated differential reduction in the levels of Aβ (1–42) (lettuce; 98.7% ± 2.4%, bitter melon; 95.9% ± 2.6%, and corn; 93.9% ± 2.1%), demonstrating that treatment with lettuce seeds extracts (LSE) effectively decreases Aβ (1–42) concentration. Among the 14 PSAE, LSE exhibited the second greatest potential for antiglycation. Inhibition of aggregates was not recognized in LSE.Conclusion:These results suggest that LSE reduces the toxicity of Aβ by modifying Aβ.

Killing Me Softly: Connotations to Unfolded Protein Response and Oxidative Stress in Alzheimer's Disease.

This review is focused on the possible causes of mitochondrial dysfunction in AD, underlying molecular mechanisms of this malfunction, possible causes and known consequences of APP, Aβ, and hyperphosphorylated tau presence in mitochondria, and the contribution of altered lipid metabolism (nonsterol isoprenoids) to pathological processes leading to increased formation and accumulation of the aforementioned hallmarks of AD. Abnormal protein folding and unfolded protein response seem to be the outcomes of impaired glycosylation due to metabolic disturbances in geranylgeraniol intermediary metabolism. The origin and consecutive fate of APP, Aβ, and tau are emphasized on intracellular trafficking apparently influenced by inaccurate posttranslational modifications. We hypothesize that incorrect intracellular processing of APP determines protein translocation to mitochondria in AD. Similarly, without obvious reasons, the passage of Aβ and tau to mitochondria is observed. APP targeted to mitochondria blocks the activity of protein translocase complex resulting in poor import of proteins central to oxidative phosphorylation. Besides, APP, Aβ, and neurofibrillary tangles of tau directly or indirectly impair mitochondrial biochemistry and bioenergetics, with concomitant generation of oxidative/nitrosative stress. Limited protective mechanisms are inadequate to prevent the free radical-mediated lesions. Finally, neuronal loss is observed in AD-affected brains typically by pathologic apoptosis.

Perceived caregiver stress in Alzheimer's disease and mild cognitive impairment: A case control study.

Objectives: Cross sectional studies have reported a tremendous amount of stress in caregivers of patients with Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). The present study aimed at evaluating the perceived stress in caregivers of patients with AD and MCI compared to controls. Materials and Methods: Caregivers of patients diagnosed with Alzheimer's disease/Mild Cognitive Impairment were recruited at the Memory Clinic of Neurology Department of a Tertiary Care Hospital in Northern India. The controls included caregivers of patients with chronic medical and psychiatric disorders. Caregivers were interviewed using Perceived Stress Scale (PSS) and the patients were assessed using The Blessed Activity of Daily Living (ADL), Mini Mental State Examination (MMSE) and Clinical Dementia Rating scale. The perceived stress of caregivers was compared amongst both groups and correlated with the severity of illness and activities of daily living of the patients. Results: Caregivers of a total of 31 patients of AD/MCI (Males = 24, Females = 7), and 30 controls (Males = 18, Females = 12) were interviewed. PSS Score was 23.29 ± 7.17 in cases and 7.5 ± 3.12 in controls. ADL Score was 7.97±5.53 in cases and 0.00 in controls. There was a significant difference between the PSS and ADL scores between those with AD and controls (P < 0.0001). Caregivers of patients with MCI had lower PSS scores compared to AD caregivers but significantly higher scores compared to caregivers of other chronic disorders. Similarly, correlation between Perceived Stress and ADL was significant (P < 0.001). Conclusions: Present study shows that caregivers of patients with AD/MCI have a high perceived stress compared to caregivers of patients with other chronic illness.

Effects of an antioxidant beverage on biomarkers of oxidative stress in Alzheimer's patients.

The purpose of the study was to test whether daily consumption of a beverage with high antioxidant power, combining extracts of green tea and apple over a period of 8months, would affect blood and urinary concentrations of biomarkers of oxidative stress in Alzheimer's patients. The study included 100 subjects, 48 of them were Alzheimer's patients, aged 76.5±3.5years, and 52 were control subjects, aged 79±4years, without dementia. Three blood and urine samples were taken from each participant, the first (T i) before starting the antioxidant or placebo beverage intake, the second (T m) 4months after the antioxidant or placebo beverage intake and the third (T f) 8months after the antioxidant or placebo beverage intake, and concentrations of biomarkers of oxidative stress were measured on serum, lysed erythrocytes or urine by UV-Vis spectrophotometry or by competitive in vitro enzyme-linked immunosorbent assay, according to the parameter analyzed. The administration of the antioxidant beverage to the Alzheimer's patients prevented the decrease in total antioxidant status in the moderate phase of the disease (T i=1.40±0.10mmol/L vs T f=1.20±0.08mmol/L), increased values of glutathione peroxidase and superoxide dismutase in initial (165 and 24% respectively) and moderate phase (75 and 85% respectively), and prevented the increase in protein carbonyls in moderate phase (T i=0.17±0.07nmol/mg protein vs T f=0.21±0.06nmol/mg protein), with a significant decrease in protein carbonyls since the fourth month of the intake in initial phase (T m=0.21±0.06nmol/mg protein vs T f=0.11±0.05nmol/mg protein). Our results suggest that antioxidant beverage could be used as a natural complementary therapy for alleviate or decrease the oxidative stress effects in the stages of Alzheimer's disease.