Neuroprotective and antioxidant effects of docosahexaenoic acid (DHA) in an experimental model of multiple sclerosis.

Multiple sclerosis (MS) is a chronic demyelinating disease, whose etiology is not yet fully understood, although there are several factors that can increase the chances of suffering from it. These factors include nutrition, which may be involved in the pathogenesis of the disease. In relation to nutrition, docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (n-3 PUFA), has emerged as an important player in the regulation of neuroinflammation, being considered a pleiotropic molecule. This study aimed to evaluate the effect of DHA supplementation on clinical state and oxidative stress produced by experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Twenty-five Dark Agouti rats which were used divided into Control Group, Control+Vehicle Group, Control+DHA Group, EAE Group, and EAE+DHA Group. DHA was administered for 51 days by intraperitoneal (i.p.) injection at a dose of 40 mg/kg, once a day, 5 days a week. DHA supplementation produced a decrease in oxidative stress, as well as an improvement in the clinical score of the disease. DHA could exert a beneficial effect on the clinic of MS, through the activation of the antioxidant factor Nrf2.

Sodium chloride-induced changes in oxidative stress, inflammation, and dysbiosis in experimental multiple sclerosis.

Objectives: The high-salt diet (HSD) has been associated with cognitive dysfunction by attacking the cerebral microvasculature, through an adaptive response, initiated in the intestine and mediated by Th17 cells. In the animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE), it has been described that NaCl causes an increase in T cell infiltration in the central nervous system. NaCl also promotes macrophage response and Th17 cell differentiation, worsening the course of the disease. HSD may trigger an activation of the immune system and enhance inflammation. However, certain studies not only do not support this possibility, but support the opposite, as the effect of salt on immune cells may not necessarily be pathogenic. Therefore, this study aimed to evaluate the effect of an over intake of salt in rats with EAE, based on the clinical course, oxidative stress, markers of inflammation and the gut dysbiosis.Methods: 15 Dark Agouti rats were used, which were divided into control group, EAE group and EAE + NaCl group. Daily 0.027 g of NaCl dissolved in 300 µl of H2O was administered through a nasogastric tube for 51 days.Results: NaCl administration produced an improvement in clinical status and a decrease in biomarkers of oxidative stress, inflammation, and dysbiosis.Conclusion: The underlying mechanism by which NaCl causes these effects could involve the renin-angiotensin-aldosterone system (RAAS), which is blocked by high doses of salt.

Effect of the Combination of Different Therapies on Oxidative Stress in the Experimental Model of Multiple Sclerosis.

Oxidative stress is heavily involved in several pathological features of Multiple Sclerosis (MS), such as myelin destruction, axonal degeneration, and inflammation. Different therapies have been shown to reduce the oxidative stress that occurs in the animal model of MS, experimental autoimmune encephalomyelitis (EAE). Some of these therapies are transcranial magnetic stimulation (TMS), extra virgin olive oil (EVOO) and S-allyl cysteine (SAC). This study aims to test the antioxidant effect of these three therapies, to compare the efficacy of SAC versus TMS and EVOO, and to analyze the effect of combining SAC + TMS and SAC and EVOO. Seventy Dark Agouti rats were used, which were divided into Control group; Vehicle group; Mock group; SAC; EVOO; TMS; SAC + EVOO; SAC + TMS; EAE; EAE + SAC; EAE + EVOO; EAE + TMS; EAE + SAC + EVOO; EAE + SAC + TMS. The TMS consisted of an oscillatory magnetic field in the form of a sine wave with a frequency of 60 Hz and an amplitude of 0.7mT (EL-EMF) applied for two hours in the morning, once a day, five days a week. SAC was administered at a dose of 50 mg/kg body weight, orally daily, five days a week. EVOO represented 10% of their calorie intake in the total standard daily diet of rats AIN-93G. All treatments were maintained for 51 days. TMS, EVOO and SAC, alone or in combination, reduce oxidative stress, increasing antioxidant defenses and also lowering the clinical score. Combination therapies do not appear to be more potent than individual therapies against the oxidative stress of EAE or its clinical symptoms.

Lactose and Casein Cause Changes on Biomarkers of Oxidative Damage and Dysbiosis in an Experimental Model of Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Experimental Autoimmune Encephalomyelitis (EAE) in rats closely reproduces Multiple Sclerosis (MS), a disease characterized by neuroinflammation and oxidative stress that also appears to extend to other organs and their compartments. The origin of MS is a matter for discussion, but it would seem that altering certain bacterial populations present in the gut may lead to a proinflammatory condition due to the bacterial Lipopolysaccharides (LPS) in the so-called brain-gut axis. The casein and lactose in milk confer anti-inflammatory properties and immunomodulatory effects. The objectives of this study were to evaluate the effects of administration of casein and lactose on the oxidative damage and the clinical status caused by EAE and to verify whether both casein and lactose had any effect on the LPS and its transport protein -LBP-. METHODS: Twenty male Dark Agouti rats were divided into control rats (control), EAE rats, and EAE rats, to which casein and lactose, EAE+casein, and EAE+lactose, respectively, were administered. Fifty-one days after casein and lactose administration, the rats were sacrificed, and different organs were studied (brain, spinal cord, blood, heart, liver, kidney, small, and large intestine). In the latter, products derived from oxidative stress were studied (lipid peroxides and carbonylated proteins) as well as the glutathione redox system, various inflammation factors (total nitrite, Nuclear Factor-kappa B p65, the Rat Tumour Necrosis Factor-α), and the LPS and LBP values. RESULTS AND CONCLUSION: Casein and lactose administration improved the clinical aspect of the disease at the same time as reducing inflammation and oxidative stress, exerting its action on the glutathione redox system, or increasing GPx levels.

Clinical and Neurochemical Effects of Transcranial Magnetic Stimulation (TMS) in Multiple Sclerosis: A Study Protocol for a Randomized Clinical Trial.

Background: Transcranial Magnetic Stimulation (TMS) is a technique based on the principles of electromagnetic induction. It applies pulses of magnetic radiation that penetrate the brain tissue, and it is a non-invasive, painless, and practically innocuous procedure. Previous studies advocate the therapeutic capacity of TMS in several neurodegenerative and psychiatric processes, both in animal models and in human studies. Its uses in Parkinson's disease, Alzheimer's disease and in Huntington's chorea have shown improvement in the symptomatology and in the molecular profile, and even in the cellular density of the brain. Consequently, the extrapolation of these TMS results in the aforementioned neurodegenerative disease to other entities with etiopathogenic and clinical analogy would raise the relevance and feasibility of its use in multiple sclerosis (MS). The overall objective will be to demonstrate the effectiveness of the TMS in terms of safety and clinical improvement, as well as to observe the molecular changes in relation to the treatment. Methods and Design: Phase II clinical trial, unicentric, controlled, randomized, single blind. A total of 90 patients diagnosed with relapsing-remitting multiple sclerosis (RRMS) who meet all the inclusion criteria and do not present any of the exclusion criteria that are established and from which clinically evaluable results can be obtained. The patients included will be assigned under the 1:1:1 randomization formula, constituting three groups for the present study: 30 patients treated with natalizumab + white (placebo) + 30 patients treated with natalizumab + TMS (1 Hz) + 30 patients treated with natalizumab + TMS (5 Hz). Discussion: Results of this study will inform on the efficiency of the TMS for the treatment of MS. The expected results are that TMS is a useful therapeutic resource to improve clinical status (main parameters) and neurochemical profile (surrogate parameters); both types of parameters will be checked. Ethics and Dissemination: The study is approved by the Local Ethics Committee and registered in https://clinicaltrials.gov (NCT04062331). Dissemination will include submission to a peer-reviewed journal, patients, associations of sick people and family members, healthcare magazines and congress presentations. Trial Registration: ClinicalTrials.gov ID: NCT04062331 (registration date: 19th/ August/2019). Version Identifier: EMTr-EMRR, ver-3, 21/11/2017.

Lipopolysaccharide Binding Protein and Oxidative Stress in a Multiple Sclerosis Model.

Recent findings in experimental autoimmune encephalomyelitis (EAE) suggest that altering certain bacterial populations present in the gut may lead to a proinflammatory condition, that could result in the development of multiple sclerosis (MS). Also, Reactive Oxygen Species seem to be involved in the course of MS. In this study, it has been aimed to relate all these variables starting from an analysis of the lipopolysaccharide (LPS) and LPS-binding protein (LBP) with the determination of parameters related to oxidative stress in the blood, brain and spinal cord. For this purpose, samples obtained from EAE rats and relapsing-remitting (RRMS) MS patients were used. In addition, EAE rats were treated with Natalizumab, N-acetyl-cysteine and dimethyl fumarate. Natalizumab was also employed in RRMS. The results of this study revealed an improvement in the clinical symptoms of the EAE and MS with the treatments, as well as a reduction in the oxidative stress parameters and in LBP. Correlations between the clinical variables of the disease, i.e. oxidative damage and LBP, were established. Although the conclusions of this research are indeed relevant, further investigation would be necessary to establish the intrinsic mechanisms of the MS-oxidative stress-microbiota relationship.

Natalizumab Modifies Catecholamines Levels Present in Patients with Relapsing- Remitting Multiple Sclerosis.

AIMS: The main aim of this study was to verify the effect of natalizumab on the levels of circulating catecholamines and indolamine and their possible relation with MS. METHODS: For this purpose, 12 healthy individuals (control group) and 12 relapsing-remitting multiple sclerosis patients (RR-MS) were selected. The patients were treated with 300 mg of natalizumab during 56 weeks (1 dose/4 weeks) (MS-56). This selection was based on the McDonalds revision criterion and scheduled to star treatment with natalizumab. Blood samples were taken before treatment (basal level) and after 56 weeks of using natalizumab. Melatonin was measured in serum and in plasma, catecholamines (dopamine, epinephrine, and norepinephrine), carbonylated proteins, 8-hydroxy-2'deoxyguanosine (8OH-dG) and the ratio reduced glutathione/oxidised glutathione (GSH/GSSG). RESULTS: The epinephrine and dopamine levels diminished in the basal group with respect to the control and did not recover normal levels with the treatment. The melatonin was decreased in RR-MS patients and went back to its normal levels with natalizumab. Norepinephrine was increased in RR-MS and decreased in MS-56 until it equalled the control group. CONCLUSION: Natalizumab normalizes altered melatonin and norepinephrine levels in MS.

Effect of natalizumab on oxidative damage biomarkers in relapsing-remitting multiple sclerosis.

BACKGROUND: Natalizumab is a monoclonal antibody used to treat multiple sclerosis. This study sought to determine whether the protective action of natalizumab involved a reduction in oxidative damage. METHODS: Twenty-two multiple sclerosis patients fulfilling the revised McDonald criteria were assigned to treatment with 300 mg natalizumab intravenously once monthly (infusion every 4 weeks) in accordance with Spanish guidelines. Carbonylated proteins, 8-hydroxy-2'-deoxyguanosine, total glutathione, reduced glutathione, superoxide dismutase, glutathione peroxidase, and myeloperoxidase levels were measured at baseline and after 14 months' treatment, and the antioxidant gap was calculated. RESULTS: Natalizumab prompted a drop in oxidative-damage biomarker levels, together with a reduction both in myeloperoxidase levels and in the myeloperoxidase/neutrophil granulocyte ratio. Interestingly, natalizumab induced nuclear translocation of Nrf2 and a fall in serum vascular cell adhesion molecule-1 levels. CONCLUSION: These findings suggest that natalizumab has a beneficial effect on oxidative damage found in MS patients.

Natalizumab y reducción de los niveles de proteínas carboniladas en pacientes con esclerosis múltiple / Natalizumab and reduction of carbonylated proteins in patients with multiple sclerosis

Introducción. Es conocida la especial sensibilidad del sistema nervioso central al daño oxidativo, así como la relación entre éste y la respuesta inflamatoria. Recientes estudios han mostrado que el estrés oxidativo está presente en la instauración y evolución de la esclerosis múltiple (EM). Uno de los más recientes tratamientos en este proceso es el natalizumab,un anticuerpo monoclonal. Objetivo. Evaluar si el efecto terapéutico del natalizumab se asocia con la gravedad de la enfermedad y el daño oxidativo. Pacientes y métodos. Se reclutó para el estudio a 20 pacientes con EM remitente recurrente (EMRR) incluidos en terapia con natalizumab y distribuidos según la Expanded Disability Status Scale (EDSS) en dos grupos: EMRR-1 (EDSS < 5) yEMRR-2 (EDSS ≥ 5). Se obtuvieron muestras sanguíneas para un estudio del perfil oxidativo.Resultados. Los datos mostraron un descenso en las proteínas carboniladas tras el tratamiento con natalizumab. La reducciónde daño oxidativo valorada como oxidación de proteínas es significativa entre la situación previa del paciente (basal) y tras 14 meses de tratamiento. El decremento más significativo coincidió con los pacientes de mayor gravedad en el proceso. Si bien no ha sido posible establecer una correlación, la significación estadística es mayor para pacientes del grupo EMRR-2 tratados con natalizumab. Por su parte, los sistemas antioxidantes no mostraron cambios estadísticamentesignificativos. Conclusión. El natalizumab induce una reducción en los niveles de proteínas carboniladas (AU)

Introduction. The sensitivity of the central nervous system to oxidative damage and its relationship with inflammatory response are well known. Recent studies have shown that oxidative stress is present in the establishment and developmentof multiple sclerosis (MS). One of the most recent treatments in this process is natalizumab, a monoclonal antibody. Aim. To evaluate whether the therapeutic effect of natalizumab is associated with the severity of the disease and the oxidative damage. Patients and methods. Researchers recruited twenty patients with relapsing-remitting MS (RRMS) undergoing therapy with natalizumab and distributed, according to the Expanded Disability Status Scale (EDSS), in two groups: RRMS-1 (EDSS< 5) and RRMS-2 (EDSS ≥ 5). Blood samples were taken for an oxidative profile study. Results. Data showed a decrease in carbonylated proteins following treatment with natalizumab. The reduction in oxidative damage rated as protein oxidation is significant between the previous (baseline) situation of the patient and after 14 months’ treatment. The most significant decrease coincided with the patients with the highest levels of severity in the process.Although it has not been possible to establish a correlation, the statistical significance is higher for patients in the RRMS-2 group treated with natalizumab. The antioxidant systems, on the other hand, did not display any tatistically significant changes.Conclusions. Natalizumab brings about a reduction in carbonylated protein levels (AU)

Peripheral oxidative stress in relapsing-remitting multiple sclerosis.

OBJECTIVES: To evaluate levels of oxidative stress in blood samples in patients with relapsing-remitting MS (RR-MS). DESIGN AND METHODS: Peripheral blood samples were collected from 24 RR-MS patients and 15 healthy controls. Levels of the following were measured: carbonylated proteins, 8-hydroxy-2'deoxyguanosine (8OHdG), total glutathione, reduced glutathione (GSH), oxidized glutathione (GSSG), GSH/GSSG ratio, superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRd), glutathione-S-transferase (GST), myeloperoxidase (MPO), antioxidant gap, total antioxidant capacity (PAO), global oxidative stress (GOS), serum vascular cell adhesion molecule-1 (sVCAM-1) and serum inter-cellular adhesion molecule 1 (sICAM-1). RESULTS: Values for carbonylated proteins, 8OHdG, total glutathione, GSH, GSH/GSSG ratio, SOD, GRd and GOS were significantly higher in RR-MS patients than in healthy controls. By contrast, PAO, GSSG, GPx and GST were lower in RR-MS patients. CONCLUSION: Oxidative stress plays a major role in MS, and is observed prior to relapse.