Modulation of the Circadian Rhythm and Oxidative Stress as Molecular Targets to Improve Vascular Dementia: A Pharmacological Perspective.

The circadian rhythms generated by the master biological clock located in the brain's hypothalamus influence central physiological processes. At the molecular level, a core set of clock genes interact to form transcription-translation feedback loops that provide the molecular basis of the circadian rhythm. In animal models of disease, a desynchronization of clock genes in peripheral tissues with the central master clock has been detected. Interestingly, patients with vascular dementia have sleep disorders and irregular sleep patterns. These alterations in circadian rhythms impact hormonal levels, cardiovascular health (including blood pressure regulation and blood vessel function), and the pattern of expression and activity of antioxidant enzymes. Additionally, oxidative stress in vascular dementia can arise from ischemia-reperfusion injury, amyloid-beta production, the abnormal phosphorylation of tau protein, and alterations in neurotransmitters, among others. Several signaling pathways are involved in the pathogenesis of vascular dementia. While the precise mechanisms linking circadian rhythms and vascular dementia are still being studied, there is evidence to suggest that maintaining healthy sleep patterns and supporting proper circadian rhythm function may be important for reducing the risk of vascular dementia. Here, we reviewed the main mechanisms of action of molecular targets related to the circadian cycle and oxidative stress in vascular dementia.

Neuromyelitis optica spectrum disorder: pathophysiological approach.

Aim: To review the main pathological findings of Neuromyelitis Optica Spectrum Disorder (NMOSD) associated with the presence of autoantibodies to aquaporin-4 (AQP4) as well as the mechanisms of astrocyte dysfunction and demyelination. Methods: An comprehensive search of the literature in the field was carried out using the database of The National Center for Biotechnology Information from . Systematic searches were performed until July 2022. Results: NMOSD is an inflammatory and demyelinating disease of the central nervous system mainly in the areas of the optic nerves and spinal cord, thus explaining mostly the clinical findings. Other areas affected in NMOSD are the brainstem, hypothalamus, and periventricular regions. Relapses in NMOSD are generally severe and patients only partially recover. NMOSD includes clinical conditions where autoantibodies to aquaporin-4 (AQP4-IgG) of astrocytes are detected as well as similar clinical conditions where such antibodies are not detected. AQP4 are channel-forming integral membrane proteins of which AQ4 isoforms are able to aggregate in supramolecular assemblies termed orthogonal arrays of particles (OAP) and are essential in the regulation of water homeostasis and the adequate modulation of neuronal activity and circuitry. AQP4 assembly in orthogonal arrays of particles is essential for AQP4-IgG pathogenicity since AQP4 autoantibodies bind to OAPs with higher affinity than for AQP4 tetramers. NMOSD has a complex background with prominent roles for genes encoding cytokines and cytokine receptors. AQP4 autoantibodies activate the complement-mediated inflammatory demyelination and the ensuing damage to AQP4 water channels, leading to water influx, necrosis and axonal loss. Conclusions: NMOSD as an astrocytopathy is a nosological entity different from multiple sclerosis with its own serological marker: immunoglobulin G-type autoantibodies against the AQP4 protein which elicits a complement-dependent cytotoxicity and neuroinflammation. Some patients with typical manifestations of NMSOD are AQP4 seronegative and myelin oligodendrocyte glycoprotein positive. Thus, the detection of autoantibodies against AQP4 or other autoantibodies is crucial for the correct treatment of the disease and immunosuppressant therapy is the first choice.

Are electrophysiological and oligodendrocyte alterations an element in the development of multiple sclerosis at the same time as or before the immune response?

Efficient communication between the glial cells and neurons is a bi-directional process that is essential for conserving normal functioning in the central nervous system (CNS). Neurons dynamically regulate other brain cells in the healthy brain, yet little is known about the first pathways involving oligodendrocytes and neurons. Oligodendrocytes are the myelin-forming cells in the CNS that are needed for the propagation of action potentials along axons and additionally serve to support neurons by neurotrophic factors (NFTs). In demyelinating diseases, like multiple sclerosis (MS), oligodendrocytes are thought to be the victims. Axonal damage begins early and remains silent for years, and neurological disability develops when a threshold of axonal loss is reached, and the compensatory mechanisms are depleted. Three hypotheses have been proposed to explain axonal damage: 1) the damage is caused by an inflammatory process; 2) there is an excessive accumulation of intra-axonal calcium levels; and, 3) demyelinated axons evolve to a degenerative process resulting from the lack of trophic support provided by myelin or myelin-forming cells. Although MS was traditionally considered to be a white matter disease, the demyelination process also occurs in the cerebral cortex. Recent data supports the notion that initial response is triggered by CNS injury. Thus, the understanding of the role of neuron-glial neurophysiology would help provide us with further explanations. We should take in account the suggestion that MS is in part an autoimmune disease that involves genetic and environmental factors, and the pathological response leads to demyelination, axonal loss and inflammatory infiltrates.

Mitochondrial ATPase activity and membrane fluidity changes in rat liver in response to intoxication with buckthorn (Karwinskia humboldtiana).

BACKGROUND: Karwinskia humboldtiana (Kh) is a poisonous plant of the rhamnacea family. To elucidate some of the subcellular effects of Kh toxicity, membrane fluidity and ATPase activities as hydrolytic and as proton-pumping activity were assessed in rat liver submitochondrial particles. Rats were randomly assigned into control non-treated group and groups that received 1, 1.5 and 2 g/Kg body weight of dry powder of Kh fruit, respectively. Rats were euthanized at day 1 and 7 after treatment. RESULTS: Rats under Kh treatment at all dose levels tested, does not developed any neurologic symptoms. However, we detected alterations in membrane fluidity and ATPase activity. Lower dose of Kh on day 1 after treatment induced higher mitochondrial membrane fluidity than control group. This change was strongly correlated with increased ATPase activity and pH gradient driven by ATP hydrolysis. On the other hand, membrane fluidity was hardly affected on day 7 after treatment with Kh. Surprisingly, the pH gradient driven by ATPase activity was significantly higher than controls despite an diminution of the hydrolytic activity of ATPase. CONCLUSIONS: The changes in ATPase activity and pH gradient driven by ATPase activity suggest an adaptive condition whereby the fluidity of the membrane is altered.

Dietary fat and antioxidant vitamin intake in patients of neurodegenerative disease in a rural region of Jalisco, Mexico.

OBJECTIVE: To evaluate and compare the intake of lipids and (A, E, and C) vitamins in patients with and without possible neurodegenerative diseases. METHODS: Twenty adults with possible Alzheimer's disease or Parkinson's disease and 41 control subjects (50-89 years old) from a rural region were studied. Dietary intake was evaluated with the analysis of macronutrients and micronutrients conducted by a food frequency questionnaire and 24 hours dietary record. Analyses were adjusted for age, sex, body mass index, and energy intake. Through interrogation and use of medical record form of health secretary we obtained information about the sociodemographic characteristics. Multivariate analysis of variance to allow for covariated adjustment was used. RESULTS: Patients had a lower energy intake, vitamin C (P = 0.016), fruits (P < 0.001), vegetables (P = 0.037), and oils and fat (P = 0.002), than the controls. Interestingly, the C vitamin intake in patients was still higher than the recommended. Patients had a higher consumption of cereals (P = 0.017), high-animal fat diet (P = 0.024), and whole milk (P < 0.001); 2.4% of the controls smoke and 5% are alcohol consumers. Eighty-five percent of patients and 78% of the controls do not have physical activity. Family history of subjects in this study indicated chronic diseases. CONCLUSION: The subjects included in this study had a high intake of C vitamin, this is due to the consumption of fruits and vegetables. However, patients with possible Alzheimer's or Parkinson's disease had a lower intake of fruits and vegetables, which could be due to type of food to which they have access.

Immunology and oxidative stress in multiple sclerosis: clinical and basic approach.

Multiple sclerosis (MS) exhibits many of the hallmarks of an inflammatory autoimmune disorder including breakdown of the blood-brain barrier (BBB), the recruitment of lymphocytes, microglia, and macrophages to lesion sites, the presence of multiple lesions, generally being more pronounced in the brain stem and spinal cord, the predominantly perivascular location of lesions, the temporal maturation of lesions from inflammation through demyelination, to gliosis and partial remyelination, and the presence of immunoglobulin in the central nervous system and cerebrospinal fluid. Lymphocytes activated in the periphery infiltrate the central nervous system to trigger a local immune response that ultimately damages myelin and axons. Pro-inflammatory cytokines amplify the inflammatory cascade by compromising the BBB, recruiting immune cells from the periphery, and activating resident microglia. inflammation-associated oxidative burst in activated microglia and macrophages plays an important role in the demyelination and free radical-mediated tissue injury in the pathogenesis of MS. The inflammatory environment in demyelinating lesions leads to the generation of oxygen- and nitrogen-free radicals as well as proinflammatory cytokines which contribute to the development and progression of the disease. Inflammation can lead to oxidative stress and vice versa. Thus, oxidative stress and inflammation are involved in a self-perpetuating cycle.

Fish oil, melatonin and vitamin E attenuates midbrain cyclooxygenase-2 activity and oxidative stress after the administration of 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine.

Parkinson's disease is a neurodegenerative disease whose hallmark pathological features include a selective loss of dopaminergic neurons in the midbrain. Ciclooxygenase-2 activity induction and oxidative stress have been implicated in the aetiology of Parkinson's disease and in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) animal model of Parkinson disease. Upon administration of fish oil, melatonin and vitamin E, neuroprotective effects on MPTP-induced neurotoxicity have been indicated. The aim of this study was to investigate the time course and compare the potency of these agents alone, on several parameters such as COX-2 and lipid peroxides (LPO) products associated with MPTP neurotoxicity in midbrain homogenates of C57BL/6 mice. Using fish oil (0.0368 g EPA and 0.0184 g DHA, per day), melatonin (10 mg/kg/day), and vitamin E (50 mg/Kg/day) we have now shown that COX-2 activity, LPO and nitrite/nitrate levels were significantly increased in MPTP treated mice (p < 0.001) while fish oil, melatonin and vitamin E treatment were capable of decreasing significantly the outcome of all above noted parameters (p < 0.05). The effect of fish oil on COX-2 activity and nitrite/nitrate levels was more profound than that of vitamin E or melatonin while the latter was more effective on reducing the LPO levels compared to fish oil and vitamin E. In conclusion, the outcome of the neuroprotective effects of these agents is long lasting and of variable potency indicating a different anti-inflammatory mode of action.

[Aging and metabolism: changes and regulation]. / Envejecimiento y metabolismo: cambios y regulación.

Studies about the effects of aging in the physiology and metabolism are increasingly, one of its objectives is to help implement programs to improve the quality of life and prevent disability in elderly. It is relevant to mention that, during aging, there is a natural metabolic deceleration, a series of changes in the regulation of energy are produced, which contributes to loss of weight and fat; the changes in the regulation of caloric intake contribute to increase the susceptibility to energy imbalance both positive and negative, which is associated with a deterioration in health. However, to grow old, is not a death sentence for metabolism, on the other hand, it can be controlled by maintaining an active lifestyle, coupled with this, research has shown that the metabolism'can be regulated by a synchronized clock (circadian rhythms), which is mediated by regulatory proteins, this relationship ensures the proper functioning of the cells and therefore good health. The aim of this review is to provide updated information on the energy- metabolism-regulation and its relationship with the great variety of components involved in energy expenditure that accompany aging, to analyze the regulation of this system to improve the quality of life and maintenance of health in old age.

Lamotrigine Extraction and Quantification by UPLC-DAD in Plasma from Patients with Bipolar Disorder.

A sensitive and efficient analytical process for detecting lamotrigine in acidic solution based in ultra-high-performance liquid chromatography-diode array detector (UPLC-DAD) was developed; the stationary phase used was a C8, 150 × 4.6 mm, 2.6 µm. The mobile phase consisted of acetonitrile/acidified water (0.01% H3PO4 and 0.005% triethylamine, pH 2.4) (25 : 75 v/v). Limits of detection and quantification were 0.02 µg/mL and 0.05 µg/mL, respectively. The working interval for the evaluation of the method ranged from 0.05 to 12 µg/mL, and the linear fit of the experimental data has a value of r2≥0.98. Before quantifying lamotrigine in plasma of patients with bipolar disorder, lamotrigine was released from plasma proteins with a 0.2 M sodium hydroxide solution, and then proteins were removed by precipitation with acetonitrile. Afterward, the lamotrigine base was dissolved in ethyl acetate. This extract was reconstituted in potassium phosphate solution (pH 2.4) to obtain more than 98% of lamotrigine protonated in N2, which was detected and quantified as indicated above. The absolute percentage of lamotrigine recovery is ≥80% for all tested concentration levels. The accuracy and precision of the method have %CV values <4% for the lamotrigine levels of 3, 6, and 9 µg/mL. The correlation coefficient for the used concentration range is 0.99. The analytical method is precise and sensitive to measure lamotrigine levels expected in plasma of BD patients and these levels were in the therapeutic dose range.

Cognitive disorder and dementia in type 2 diabetes mellitus.

Insulin, a key pleiotropic hormone, regulates metabolism through several signaling pathways in target tissues including skeletal muscle, liver, and brain. In the brain, insulin modulates learning and memory, and impaired insulin signaling is associated with metabolic dysregulation and neurodegenerative diseases. At the receptor level, in aging and Alzheimer's disease (AD) models, the amount of insulin receptors and their functions are decreased. Clinical and animal model studies suggest that memory improvements are due to changes in insulin levels. Furthermore, diabetes mellitus (DM) and insulin resistance are associated with age-related cognitive decline, increased levels of ß-amyloid peptide, phosphorylation of tau protein; oxidative stress, pro-inflammatory cytokine production, and dyslipidemia. Recent evidence shows that deleting brain insulin receptors leads to mild obesity and insulin resistance without influencing brain size and apoptosis development. Conversely, deleting insulin-like growth factor 1 receptor (IGF-1R) affects brain size and development, and contributes to behavior changes. Insulin is synthesized locally in the brain and is released from the neurons. Here, we reviewed proposed pathophysiological hypotheses to explain increased risk of dementia in the presence of DM. Regardless of the exact sequence of events leading to neurodegeneration, there is strong evidence that mitochondrial dysfunction plays a key role in AD and DM. A triple transgenic mouse model of AD showed mitochondrial dysfunction, oxidative stress, and loss of synaptic integrity. These alterations are comparable to those induced in wild-type mice treated with sucrose, which is consistent with the proposal that mitochondrial alterations are associated with DM and contribute to AD development. Alterations in insulin/IGF-1 signaling in DM could lead to mitochondrial dysfunction and low antioxidant capacity of the cell. Thus, insulin/IGF-1 signaling is important for increased neural processing and systemic metabolism, and could be a specific target for therapeutic strategies to decrease alterations associated with age-related cognitive decline.

Occupational exposure to organophosphorus and carbamates in farmers in La Cienega, Jalisco, Mexico: oxidative stress and membrane fluidity markers.

BACKGROUND: The region of La Cienega in Jalisco Mexico, is an important agricultural reference for the production of corn, sorghum and wheat, among other grains, so the use of pesticides for pest control is high. However, in this rural area there are no toxicological studies that assess the occupational risk of pesticide use. Therefore, this study is the first to determine the oxidative stress levels markers (GSH, GSSG, carbonyl groups, nitric oxide metabolites and lipid peroxides) as well as alteration of the mitochondrial membrane fluidity caused by occupational exposure to organophosphorus and carbamates in farmers of this region. This occupational risk can increase cellular oxidation, which explains the high prevalence of neurodegenerative diseases and cancer in Cienega settlers to be analyzed in future studies. METHODS: Comparative cross-sectional study was performed using two groups: one not exposed group (n = 93) and another one with occupational exposure (n = 113). The latter group was sub-divided into 4 groups based on duration of use/exposure to pesticides. Oxidative stress levels and membrane fluidity were assessed using spectrophotometric methods. Statistical analyses were performed using SPSS software ver. 19.0 for windows. RESULTS: The most commonly used pesticides were organophosphorus, carbamates, herbicide-type glyphosate and paraquat, with an average occupational exposure time of 35.3 years. There were statistically significant differences in markers of oxidative stress between exposed farmers and not exposed group (p = 0.000). However, in most cases, no significant differences were found in markers of oxidative stress among the 4 exposure sub-groups (p > 0.05). CONCLUSION: In the Cienega region, despite the indiscriminate use of organophosphorus and carbamates, there are no previous studies of levels oxidative stress. The results show increased levels of oxidative stress in occupationally exposed farmers, particularly membrane fluidity levels increased three times in contrast to not exposed group.

Oxidative stress is increased in serum from Mexican patients with relapsing-remitting multiple sclerosis.

OBJECTIVE: To determine the oxidative stress markers in serum from patients with relapsing-remitting multiple sclerosis. METHODS: Blood samples from healthy controls and 22 patients 15 women (7 aged from 20 to 30 and 8 were > 40 years old) and 7 men (5 aged from 20 to 30 and 2 were > 40 years old) fulfilling the McDonald Criteria and classified as having Relapsing-Remitting Multiple Sclerosis accordingly with Lublin were collected for oxidative stress markers quantification. RESULTS: Nitric oxide metabolites (nitrates/nitrites), lipid peroxidation products (malondialdehyde plus 4-hidroxialkenals), and glutathione peroxidase activity were significantly increased in serum of subjects with relapsing-remitting multiple sclerosis in comparison with that of healthy controls. These data support the hypothesis that multiple sclerosis is a component closely linked to oxidative stress.

Cellular and biochemical actions of melatonin which protect against free radicals: role in neurodegenerative disorders.

Molecular oxygen is toxic for anaerobic organisms but it is also obvious that oxygen is poisonous to aerobic organisms as well, since oxygen plays an essential role for inducing molecular damage. Molecular oxygen is a triplet radical in its ground-stage (.O-O.) and has two unpaired electrons that can undergoes consecutive reductions of one electron and generates other more reactive forms of oxygen known as free radicals and reactive oxygen species. These reactants (including superoxide radicals, hydroxyl radicals) possess variable degrees of toxicity. Nitric oxide (NO*) contains one unpaired electron and is, therefore, a radical. NO* is generated in biological tissues by specific nitric oxide synthases and acts as an important biological signal. Excessive nitric oxide production, under pathological conditions, leads to detrimental effects of this molecule on tissues, which can be attributed to its diffusion-limited reaction with superoxide to form the powerful and toxic oxidant, peroxynitrite.Reactive oxygen and nitrogen species are molecular "renegades"; these highly unstable products tend to react rapidly with adjacent molecules, donating, abstracting, or even sharing their outer orbital electron(s). This reaction not only changes the target molecule, but often passes the unpaired electron along to the target, generating a second free radical, which can then go on to react with a new target amplifying their effects.This review describes the mechanisms of oxidative damage and its relationship with the most highly studied neurodegenerative diseases and the roles of melatonin as free radical scavenger and neurocytoskeletal protector.

Efficacy of Melatonin on Serum Pro-inflammatory Cytokines and Oxidative Stress Markers in Relapsing Remitting Multiple Sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory disease, which leads to focal plaques of demyelination and tissue injury in the central nervous system (CNS). Neuroinflammation and oxidative stress are involved in the pathogenesis of MS, promoting tissue damage and demielinization. Current research findings suggest that melatonin has antioxidant and neuroprotective effects. The aim of this study was to evaluate the efficacy of melatonin on serum pro-inflammatory cytokines and oxidative stress markers in relapsing-remitting multiple sclerosis (RRMS). 36 patients diagnose with RRMS treated with Interferon ß-1b (IFNß-1b) were enrolled in a double bind, randomized, placebo controlled trial. The experimental group received orally 25 mg/d of melatonin for 6 months. After melatonin administration, we observed a significant decrease in serum concentration of pro-inflammatory cytokines and oxidative stress markers; 18% for TNF-α (p <0.05), 34.8% for IL-1ß (p <0.05), 34.7% for IL-6 (p <0.05), 39.9% for lipoperoxides (LPO) (p <0.05) and 24% for nitric oxide catabolites (NOC) levels (p <0.05), compared with placebo group. No significant difference in clinical efficacy outcomes were found between groups. Melatonin treatment was well tolerated and we did not observe significant differences in rates of side effects between the two groups. We concluded that melatonin administration during 6 months period is effective in reducing levels of serum pro-inflammatory cytokines and oxidative stress markers in patients with RRMS. These data support future studies evaluating the safety and effectiveness of melatonin supplementation in RRMS patients.

Effect of fish and olive oil on mitochondrial ATPase activity and membrane fluidity in patients with relapsing-remitting multiple sclerosis treated with interferon beta 1-b.

BACKGROUND: Multiple sclerosis (MS) is an inflammatory disease of the central nervous system associated with increased oxidative stress (OS) and mitochondrial alterations. Fish oil consumption has neuroprotective, antioxidant and anti-inflammatory effects in patients with relapsing-recurrent MS (RR-MS). OBJECTIVE: To evaluate changes in the hydrolytic activity of ATP synthase and mitochondrial membrane fluidity in patients with RR-MS who receive fish oil or olive oil as a dietary supplement. METHODS: Clinical, controlled, randomized, double-blind trial. Patients consumed fish oil or olive oil for one year. The hydrolytic activity of ATPase and the fluidity of the mitochondrial membrane of platelets were quantified. RESULTS: In patients with RR-MS, a decrease in the fluidity of mitochondrial membranes and an increase in the hydrolytic activity of ATP synthase was observed in comparison with healthy controls. After 6 or 9 months of treatment with fish oil or olive oil, respectively, these values were normalized. CONCLUSION: The consumption of fish oil and olive oil increases the fluidity of the mitochondrial membranes and decreases the catabolic activity of ATP synthase in platelets from patients with RR-MS.

Dietary fish oil increases catalase activity in patients with probable Alzheimer's disease / El aceite de pescado en la dieta aumenta la actividad de la catalasa en pacientes con probable enfermedad de Alzheimer

Background: Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the presence of neuritic plaques and neurofibrillary tangles that finally result in synaptic and neuronal loss. Oxidative stress accompanies pathological changes in AD. Objective: to assess the efficacy of dietary omega 3 polyunsaturated fatty acids supplementation on the levels of proteins oxidation, hydroperoxides and enzymatic activities of catalase and superoxide dismutase in AD patients. Methods: clinical, controlled, randomized, double-blind trial. Patients consumed fish oil or placebo for one year. Oxidative stress markers were assessed in plasma using spectrophotometric methods. Results: carbonyl groups in proteins and hydroperoxides in plasma have similar values in both treatment groups at the beginning of the study. At six and 12 months of treatment, these values decreased significantly in the fish oil group, while in the placebo group no changes were observed in both oxidative stress markers. Catalase activity increased significantly at six and twelve months after treatment in patients treated with fish oil. While the superoxide dismutase activity was not modified in both study groups. Conclusions: patients who consume omega 3 polyunsaturated fatty acids at a stable dose of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) show decreased oxidation of proteins and lipids in plasma. In addition, an increase in catalase activity was detected. Thus, the presented data warrants further studies evaluating the antioxidant effect of omega 3 polyunsaturated fatty acids. (AU)

Antecedentes: la enfermedad de Alzheimer (EA) es un trastorno neurodegenerativo caracterizado por la presencia de placas neuríticas y ovillos neurofibrilares que finalmente resultan en pérdida sináptica y neuronal. El estrés oxidativo acompaña los cambios patológicos en la EA. Objetivo: evaluar la eficacia de la suplementación dietética con ácidos grasos poliinsaturados omega 3 sobre los niveles de oxidación de proteínas, hidroperóxidos y actividades enzimáticas de catalasa y superóxido dismutasa en pacientes con EA. Métodos: ensayo clínico, controlado, aleatorizado, doble ciego. Los pacientes consumieron aceite de pescado o placebo durante un año. Los marcadores de estrés oxidativo se evaluaron en plasma mediante métodos espectrofotométricos. Resultados: los grupos carbonilo en proteínas e hidroperóxidos en plasma tuvieron valores similares en ambos grupos de tratamiento al inicio del estudio. A los seis y 12 meses de tratamiento estos valores disminuyeron significativamente en el grupo de aceite de pescado, mientras que en el grupo placebo no se observaron cambios en ambos marcadores. La actividad de catalasa aumentó significativamente a los seis y doce meses después del tratamiento en pacientes tratados con aceite de pescado; sin embargo, la actividad superóxido dismutasa no se modificó en ambos grupos de estudio. Conclusiones: los pacientes que consumieron los ácidos grasos poliinsaturados omega 3 a una dosis estable de ácido docosahexaenoico (DHA) y ácido eicosapentaenoico (EPA) muestran una oxidación reducida de proteínas y lípidos en plasma. Además, se detectó un aumento en la actividad de la catalasa. Por tanto, los datos presentados justifican más estudios que evalúen el efecto antioxidante de dichos ácidos grasos. (AU)

Oxidative Stress: Love and Hate History in Central Nervous System.

Molecular oxygen is essential for aerobic organisms in order to synthesize large amounts of energy during the process of oxidative phosphorylation and it is harnessed in the form of adenosine triphosphate, the chemical energy of the cell. Oxygen is toxic for anaerobic organisms but it is also less obvious that oxygen is poisonous to aerobic organisms at higher concentrations of oxygen. For instance, oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen at increased partial pressures. Reactive oxygen species (ROS) are chemically reactive molecules containing oxygen that are formed as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis. However, in pathological conditions ROS levels can increase dramatically. This may result in significant damage to cell structures. Living organisms have been adapted to the ROS in two ways: they can mitigate the unwanted effects through removal by the antioxidant systems and can advantageously use them as messengers in cell signaling and regulation of body functions. Some other physiological functions of ROS include the regulation of vascular tone, detection, and adaptation to hypoxia. In this review, we describe the mechanisms of oxidative damage and its relationship with the most highly studied neurodegenerative diseases.

Effect of fish oil on glutathione redox system in multiple sclerosis.

UNLABELLED: Multiple sclerosis (MS) is a chronic, inflammatory and autoimmune disease of the central nervous system. Dysregulation of glutathione homeostasis and alterations in glutathione-dependent enzyme activities are implicated in the induction and progression of MS. Evidence suggests that Omega-3 polyunsaturated fatty acids (PUFAs) have anti-inflammatory, antioxidant and neuroprotective effects. The aim of the present work was to evaluate the effect of fish oil on the activity of glutathione reductase (GR), content of reduced and oxidized glutathione, and GSH/GSSG ratio in MS. 50 patients with relapsing-remitting MS were enrolled. The experimental group received orally 4 g/day of fish oil for 12 months. Fish oil supplementation resulted in a significant increase in n-3 fatty acids and a decrease n-6 fatty acids. No differences in glutathione reductase activity, content of reduced and oxidized glutathione, and GSH/GSSG ratio were found. CONCLUSION: Glutathione reductase activity was not significantly different between the groups; however, fish oil supplementation resulted in smaller increase in GR compared with control group, suggesting a possible effect on antioxidant defence mechanisms.

Omega 3 Fatty Acids Supplementation and Oxidative Stress in HIV-Seropositive Patients. A Clinical Trial.

HIV-seropositive patients show high incidence of coronary heart disease and oxidative stress has been described as relevant key in atherosclerosis development. The aim of this study was to assess the effect of omega 3 fatty acids on different markers of oxidative stress in HIV-seropositive patients. We performed a randomized parallel controlled clinical trial in The Instituto Mexicano del Seguro Social, a public health hospital. 70 HIV-seropositive patients aged 20 to 55 on clinical score A1, A2, B1 or B2 receiving highly active antiretroviral therapy (HAART) were studied. They were randomly assigned to receive omega 3 fatty acids 2.4 g (Zonelabs, Marblehead MA) or placebo for 6 months. At baseline and at the end of the study, anthropometric measurements, lipid profile, glucose and stress oxidative levels [nitric oxide catabolites, lipoperoxides (malondialdehyde plus 4-hydroxialkenals), and glutathione] were evaluated. Principal HAART therapy was EFV/TDF/FTC (55%) and AZT/3TC/EFV (15%) without difference between groups. Treatment with omega 3 fatty acids as compared with placebo decreased triglycerides (-0.32 vs. 0.54 mmol/L; p = 0.04), but oxidative stress markers were not different between groups.

Effect of fish oil on oxidative stress markers in patients with probable Alzheimer´s disease

High intake of omega-3 fatty acids has been associated with synaptic plasticity, neurogenesis and memory in several experimental models. To assess the efficacy of fish oil supplementation on oxidative stress markers in patients diagnosed with probable Alzheimer´s disease (AD) we conducted a double blind, randomized, placebo controlled clinical trial. AD patients who met the inclusive criteria were given fish oil (containing 0.45 g eicosapentaenoic acid and 1 g docosahexaenoic acid) or placebo daily for 12 months. Oxidative stress markers [lipoperoxides, nitric oxide catabolites levels, oxidized/reduced glutathione ratio, and membrane fluidity] and fatty acid profile in erythrocytes were assessed at enrollment, and 6 and 12 months after the start of the testing period. At the end of the trial, in patients who received fish oil, we detected a decrease in the omega 6/omega 3 ratio in erythrocyte membrane phospholipids. This change was parallel with decreases in plasma levels of lipoperoxides and nitric oxide catabolites. Conversely, the ratio of reduced to oxidized glutathione was significantly increased. In addition, membrane fluidity was increased significantly in plasma membrane samples. In conclusion fish oil administration has a beneficial effect in decreasing the levels of oxidative stress markers and improving the membrane fluidity in plasma(AU)

El alto consumo de ácidos grasos omega-3 se asocia con la plasticidad sináptica, neurogénesis y memoria en varios modelos experimentales. Para evaluar la eficacia de la suplementación con aceite de pescado en los marcadores de estrés oxidativo en pacientes con diagnóstico de la enfermedad de Alzheimer (EA) probable realizamos un ensayo clínico doble ciego, aleatorizado, controlado con placebo. A los pacientes con la EA que cumplían los criterios de inclusión se les administró aceite de pescado (que contenía 0,45 g de ácido eicosapentaenoico y 1 g de ácido docosahexaenoico) o placebo diariamente durante 12 meses. Los marcadores de estrés oxidativo plasmático [niveles de lipoperóxidos y catabolitos del óxido nítrico, cociente de glutatión reducido a glutatiónoxidado) y fluidez de la membrana] y el perfil de ácidos grasos en los eritrocitos se evaluaron al inicio, 6 meses y alos 12 meses. Al final del ensayo, en pacientes que recibieron aceite de pescado detectamos una disminución en el cociente de ácidos grasos omega 6/omega 3 en los fosfolípidos de la membrana eritrocitaria. Este cambio ocurrió en paralelo a la disminución de los niveles plasmáticos de lipoperóxidos y catabolitos del óxido nítrico. Por el contrario, el cociente de glutatión reducido a glutatión oxidado se incrementó significativamente. Además, la fluidez de la membrana aumentó significativamente en las muestras analizadas. En conclusión, la administración de aceite de pescado tiene un efecto beneficioso al disminuir los niveles de marcadores de estrés oxidativo plasmático y mejorar la fluidez de la membrana plasmática(AU)