Antioxidant therapy in multiple sclerosis

Relationship between inflammation and oxidative stress and its effect on multiple sclerosis

INTRODUCTION

This paper highlights the relationship of inflammation and oxidative stress as damage mechanisms of Multiple Sclerosis (MS), considered an inflammatory and autoimmune disease.

DEVELOPMENT

The oxidative stress concept has been defined by an imbalance between oxidants and antioxidants in favor of the oxidants. There is necessary to do physiological functions, like the respiration chain, but in certain conditions, the production of reactive species overpassed the antioxidant systems, which could cause tissue damage. On the other hand, it is well established that inflammation is a complex reaction in the vascularized connective tissue in response to diverse stimuli. However, an unregulated prolonged inflammatory process also can induce tissue damage.

CONCLUSION

Both inflammation and oxidative stress are interrelated since one could promote the other, leading to a toxic feedback system, which contributes to the inflammatory and demyelination process in MS.

Neuroprotection by acrolein sequestration through exogenously applied scavengers and endogenous enzymatic enabling strategies in mouse EAE model

We have previously shown that the pro-oxidative aldehyde acrolein is a critical factor in MS pathology. In this study, we found that the acrolein scavenger hydralazine (HZ), when applied from the day of induction, can suppress acrolein and alleviate motor and sensory deficits in a mouse experimental autoimmune encephalomyelitis (EAE) model. Furthermore, we also demonstrated that HZ can alleviate motor deficits when applied after the emergence of MS symptoms, making potential anti-acrolein treatment a more clinically relevant strategy. In addition, HZ can reduce both acrolein and MPO, suggesting a connection between acrolein and inflammation. We also found that in addition to HZ, phenelzine (PZ), a structurally distinct acrolein scavenger, can mitigate motor deficits in EAE when applied from the day of induction. This suggests that the likely chief factor of neuroprotection offered by these two structurally distinct acrolein scavengers in EAE is their common feature of acrolein neutralization. Finally, up-and-down regulation of the function of aldehyde dehydrogenase 2 (ALDH2) in EAE mice using either a pharmacological or genetic strategy led to correspondent motor and sensory changes. This data indicates a potential key role of ALDH2 in influencing acrolein levels, oxidative stress, inflammation, and behavior in EAE. These findings further consolidate the critical role of aldehydes in the pathology of EAE and its mechanisms of regulation. This is expected to reinforce and expand the possible therapeutic targets of anti-aldehyde treatment to achieve neuroprotection through both endogenous and exogenous manners.

Factors influencing the degree of disability in patients with neuromyelitis optica spectrum disorders

OBJECTIVE

To investigate the factors influencing the degree of disability in patients with neuromyelitis optica spectrum disorder (NMOSD) and provide evidence for disease monitoring and clinical intervention.

METHODS

Eighty-four patients with NMOSD at Xuanwu Hospital Capital Medical University were enrolled in this retrospective study. Before treatment, blood was collected from all patients, and their expanded disability status scores were assessed.

RESULTS

Of the 84 patients assessed, 66 (78.57%) had an expanded disability status scale score < 7, and 18 (21.43%) had scores ≥ 7. The univariate analysis showed that the total bilirubin (TBil), cerebrospinal fluid albumin (CSF ALB), cerebrospinal fluid immunoglobulin G (CSF IgG), QALB, and QIgG levels in the group with scores ≥ 7 were significantly different from those with scores < 7 (P < 0.05). In addition, Spearman's correlation analysis showed a significant correlation between ALB and expanded disability status scores in patients with NMOSD (P < 0.05), and the multivariate logistic regression analysis showed that TBil was an independent factor influencing the degree of disability in patients with NMOSD (P < 0.05). The receiver operating characteristic curve was constructed using TBil values; the area under the curve of TBil was 0.729 (P < 0.01), and the best cut-off value was 11.015 g/L. Its sensitivity in predicting the severity of disability in NMOSD patients was 51.5% while its specificity was 88.9%.

CONCLUSION

TBil is an independent factor that influences the severity of disability in patients with NMOSD. In addition, ALB is closely related to NMOSD severity, and some factors associated with the BBB are significantly increased in severely disabled NMOSD patients.

Chelation Therapy Associated with Antioxidant Supplementation Can Decrease Oxidative Stress and Inflammation in Multiple Sclerosis: Preliminary Results

An imbalance of oxy-inflammation status has been involved in axonal damage and demyelination in multiple sclerosis (MS). The aim of this study was to investigate the efficacy of an antioxidant treatment (calcium disodium ethylenediaminetetracetic acid-EDTA) chelation therapy associated with a micronutrient complex in MS patients. A total of 20 MS patients and 20 healthy subjects, enrolled as a control group (CTR), were recruited. We measured the plasma ROS production and total antioxidant capacity (TAC) by a direct assessment using Electron Paramagnetic Resonance; activities of the antioxidant system (thiols' redox status and enzymes); and the urinary presence of biomarkers of oxidative stress by immunoenzymatic assays. We also evaluated the levels of inflammation by plasmatic cytokines (TNFα, IL-1β, and IL-6) and assessed the sICAM levels, as well as the nitric oxide (NO) catabolism and transthyretin (TTR) concentration. Comparing CTR and MS, in the latter ROS production, oxidative damage, inflammatory biomarkers, and NO metabolite concentrations results were significantly higher, while TAC was significantly lower. Treatment in MS induced significant (p < 0.05) down-regulating of pro-inflammatory sICAM1, TNF-α, IL6, as well as biomarkers of lipid peroxidation and DNA damage production. The protective effect exhibited may occur by decreasing ROS production and increasing antioxidant capacity, turning into a more reduced thiols' status.

Exogenous Antioxidants in Remyelination and Skeletal Muscle Recovery

Inflammatory, oxidative, and autoimmune responses cause severe damage to the nervous system inducing loss of myelin layers or demyelination. Even though demyelination is not considered a direct cause of skeletal muscle disease there is extensive damage in skeletal muscles following demyelination and impaired innervation. In vitro and in vivo evidence using exogenous antioxidants in models of demyelination is showing improvements in myelin formation alongside skeletal muscle recovery. For instance, exogenous antioxidants such as EGCG stimulate nerve structure maintenance, activation of glial cells, and reduction of oxidative stress. Consequently, this evidence is also showing structural and functional recovery of impaired skeletal muscles due to demyelination. Exogenous antioxidants mostly target inflammatory pathways and stimulate remyelinating mechanisms that seem to induce skeletal muscle regeneration. Therefore, the aim of this review is to describe recent evidence related to the molecular mechanisms in nerve and skeletal muscle regeneration induced by exogenous antioxidants. This will be relevant to identifying further targets to improve treatments of neuromuscular demyelinating diseases.

Decreased Cerebrospinal Fluid Antioxidative Capacity Is Related to Disease Severity and Progression in Early Multiple Sclerosis

Background: Oxidative stress-induced neuronal damage in multiple sclerosis (MS) results from an imbalance between toxic free radicals and counteracting antioxidants, i.e., antioxidative capacity (AOC). The relation of AOC to outcome measures in MS still remains inconclusive. We aimed to compare AOC in cerebrospinal fluid (CSF) and serum between early MS and controls and assess its correlation with clinical/radiological measures. Methods: We determined AOC (ability of CSF and serum of patients to inhibit 2,2′-azobis(2-amidinopropane) dihydrochloride-induced oxidation of dihydrorhodamine) in clinically isolated syndrome (CIS)/early relapsing-remitting MS (RRMS) (n = 55/11) and non-inflammatory neurological controls (n = 67). MS patients underwent clinical follow-up (median, 4.5; IQR, 5.2 years) and brain MRI at 3 T (baseline/follow-up n = 47/34; median time interval, 3.5; IQR, 2.1 years) to determine subclinical disease activity. Results: CSF AOC was differently regulated among CIS, RRMS and controls (p = 0.031) and lower in RRMS vs. CIS (p = 0.020). Lower CSF AOC correlated with physical disability (r = −0.365, p = 0.004) and risk for future relapses (exp(β) = 0.929, p = 0.033). No correlations with MRI metrics were found. Conclusion: Decreased CSF AOC was associated with increased disability and clinical disease activity in MS. While our finding cannot prove causation, they should prompt further investigations into the role of AOC in the evolution of MS.

Beneficial effects of a nano formulation of pomegranate seed oil, GranaGard, on the cognitive function of multiple sclerosis patients

BACKGROUND

Though often neglected, cognitive impairment is a common feature of multiple sclerosis in 43-70% of patients. None of the novel MS treatment seems to substantially affect or restore cognitive disability in MS. GranaGard (Granalix Bio Technologies LTD) is a food supplement shown to prevent neuronal death in several animal models of neurological diseases. Capsules of GranaGard comprise a self-emulsion nano formulation of pomegranate seed oil (PSO). This oil contains 80-90% of Punicic Acid (PA), one of the strongest natural antioxidants. In animal experiments, administration of GranaGard results in conjugation with linoleic acid (CLA), the main metabolite of PA, which is a well-known neuroprotective agent.

AIMS

To investigate whether GranaGard administration has an effect on the cognitive state of MS patients.

METHODS

This is a single center, randomized double blind clinical trial that started in May 2018. The study included 30 MS patients; half of them (Group-A) were given GranaGard for the first three months and then placebo pills containing soybean oil for additional three months. Patients in Group-B received placebo for the first three months, and GranaGard for the following three months. GranaGard was administrated in addition to their immunomodulatory MS-treatments. Subsequently, all patients received GranaGard for additional six months. Patients were required to visit the neurologist at baseline (inclusion, visit 1) and at 3 months after treatment-initiation at each cycle of the trial (visits 2 and 3). During the follow up visits, clinical and cognitive examinations were performed, including Expanded Disability Status Scale (EDSS), Multiple Sclerosis Functional Composite (MSFC: 25 ft walking test, 9 PEG hole test & PASAT). Cognitive tests included The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) battery: 1) Symbol Digit Modalities Test (SDMT); 2) California Verbal Learning Test - Second Edition (CVLT-II); 3) and Brief Visuospatial Memory Test - Revised (BVMT-R). Cognitive outcomes were normalized to the healthy population and expressed as z-scores, depended on age, gender and education. Short quality of life and fatigue questionnaires (SF-12, MFIS-5) were also provided by the participants.

RESULTS

No serious adverse effects, related to the product, were observed during the study period. All patients receiving GranaGard reported a ''positive'' effect in their ADL while using the product. While there were no significant differences in the clinical parameters of disability (EDSS scores) between the treatment groups, there was a trend of beneficial effect of GranaGard, on the verbal testing during the first 3-month period of treatment. The z score for CVLT-II, significantly increased (from 0.891 to 1.415, p = 0.012, Wilcoxon rank test) at 3-months in the group of patients who were treated with GranaGard, as compared to baseline. A similar (but not statistically significant) trend was seen also in the BVMTr testing during the same 3 months-period, whereas there was no change in the SDMT. The overall average z-score of all three cognitive functions was significantly improved in the three months of Granagard treatment (-0.0077 at 3 months vs 0.462 at baseline, p = 0.034, Wilcoxon rank test). During the same 3-months period there were no significant changes in the placebo-treated group. For the patients receiving GranaGard in the initial 3 months, the value of z score of CVLT-II remained high (z = 1.415) also at the following three months (while they received placebo), suggesting a longer lasting effect for at least 3 months after discontinuation of the drug.

CONCLUSION

This is the first study in which GranaGard, a brain targeted nano-formulation of PSO, was tested in humans. Our results in this small pilot, controlled trial provide indications that GranaGard administration to MS patients might improve/stabilize cognitive disability. Larger studies with longer duration, are needed to confirm these initial observations.

Forearm muscle mitochondrial capacity and resting oxygen uptake: Relationship to symptomatic fatigue in persons with multiple sclerosis

Background

Mitochondrial dysfunction has been implicated in the pathogenesis of multiple sclerosis (MS). Whether mitochondrial alterations are a function of ambulatory dysfunction or are of a non-ambulatory systemic nature is unclear.

Objective

To compare oxidative capacity, and rest muscle oxygen consumption (mVO₂) in the upper limb of persons with multiple sclerosis (PwMS) to a control group (CON), whereby an upper limb would be comparatively independent of ambulation or deconditioning.

Methods

Near infra-red spectroscopy was used to measure oxidative capacity of the wrist flexors in PwMS (n = 16) and CON (n = 13). Oxidative capacity was indicated by the time constant (TC) of mVO₂ recovery following brief wrist flexion contractions. Measurements included well-being, depression, symptomatic fatigue, disability, handgrip strength, cognition, and functional endurance. Analysis was by T-tests and Pearson correlations with p ≤ 0.05. Data are mean (SD).

Results

TC of mVO₂ recovery was slower in PwMS (MS = 47(14) sec, CON = 36(11) sec; p = 0.03). No significant correlations were found between oxidative capacity and any other measures. Rest mVO₂ was not different between groups, but correlated with symptomatic fatigue (r = 0.694, p = 0.003) and strength (0.585, p = 0.017) in PwMS.

Conclusion

Oxidative capacity was lower in the wrist flexors of PwMS, possibly indicating a systemic component of the disease. Within PwMS, rest mVO₂ was associated with symptomatic fatigue.

Amifostine ameliorates induction of experimental autoimmune encephalomyelitis: Effect on reactive oxygen species/NLRP3 pathway

Multiple sclerosis (MS) is an autoimmune disease for which conventional treatments have limited efficacy or side effects. Free radicals are primarily involved in blood-brain barrier disruption and induce neuronal and axonal damage, thus promoting the development of MS. Amifostine, a radioprotective drug used as a cytoprotective agent, attenuates oxidative stress and improves radiation damage by acting as a direct scavenger of reactive oxygen and nitrogen species. The aim of this study was to evaluate the effects of amifostine on MS in a mouse model of experimental autoimmune encephalomyelitis (EAE), which was developed by immunizing C57BL/6 mice with myelin oligodendrocyte glycoprotein and pertussis toxin. EAE mice received intraperitoneal injections of amifostine prior to onset of clinical symptoms and were monitored up to day 15 post induction. We observed abnormal clinical behavioral scores and a decrease in body weight. Histological analysis showed severe inflammatory infiltration and demyelination in the brain and spinal cord lumbar enlargements where significant upregulation of the mRNA expression of the pro-inflammatory cytokines interleukin-6 and interleukin-8, downregulation of the anti-inflammatory cytokine interleukin-10, and obvious microgliosis were also observed. Amifostine treatment potently reversed these abnormal changes. The anti-inflammatory effect of amifostine was associated with the inhibition of reactive oxygen species generation. Furthermore, the expression of proteins involved in the NLRP3 signaling pathway and pyroptosis was decreased. In conclusion, our study showed that amifostine ameliorates induction of experimental autoimmune encephalomyelitis via anti-inflammatory and anti-pyroptosis effects, providing further insights into the use of amifostine for the treatment of MS.

A review of the effects of the anesthetic gas nitrous oxide on the immune system; a starting point for future experiences

Nitrous oxide is a common gas used as an anesthetic agent and analgesic medication in operating rooms. The gas inhibits vitamin B₁₂ dependent-methionine synthase, which converts L-homocysteine and 5-methyltetrahydrofolate to L-methionine and tetrahydrofolate, respectively, via a methylation process. The immune system has been frequently reported to be suppressed in anesthetized subjects during the postoperative period. Although previous reviews have focused on the pathophysiologic role of nitrous oxide, none of them has considered the harmful effects of nitrous oxide on the Defense system of the host. In this article, the authors review current studies on the effects of nitrous oxide on the immune system of both patients undergoing surgery and occupational exposure, as well as preclinical studies. Moreover, this paper opens a new horizon for future studies in the context of underlying mechanisms of nitrous oxide actions on the immune system.

New insights in the mechanisms of impaired redox signaling and its interplay with inflammation and immunity in multiple sclerosis

Multiple sclerosis (MS) is an autoimmune neurological disease characterized by chronic inflammation of the central nervous system (CNS), leading to demyelination and axonal damage and resulting in a range of physical, mental or even psychiatric symptoms. Key role of oxidative stress (OS) in the pathogenesis of MS has been suggested, as indicated by the biochemical analysis of cerebrospinal fluid and blood samples, tissue homogenates, and animal models of multiple sclerosis. OS causes demyelination and neurodegeneration directly, by oxidation of lipids, proteins and DNA but also indirectly, by inducing a dysregulation of the immunity and favoring the state of pro-inflammatory response. In this review, we discuss the interrelated mechanisms of the impaired redox signaling, of which the most important are inflammation-induced production of free radicals by activated immune cells and growth factors, release of iron from myelin sheath during demyelination and mitochondrial dysfunction and consequent energy failure and impaired oxidative phosphorylation. Review also provides an overview of the interplay between inflammation, immunity and OS in MS. Finally, this review also points out new potential targets in MS regarding attenuation of OS and inflammatory response in MS.

Lipoic Acid and Other Antioxidants as Therapies for Multiple Sclerosis

Oxidative stress (OS), when oxidative forces outweigh endogenous and nutritional antioxidant defenses, contributes to the pathophysiology of multiple sclerosis (MS). Evidence of OS is found during acute relapses, in active inflammatory lesions, and in chronic, longstanding plaques. OS results in both ongoing inflammation and neurodegeneration. Antioxidant therapies are a rational strategy for people with MS with all phenotypes and disease durations. PURPOSE OF REVIEW: To understand the function of OS in health and disease, to examine the contributions of OS to MS pathophysiology, and to review current evidence for the effects of selected antioxidant therapies in people with MS (PwMS) with a focus on lipoic acid (LA). RECENT FINDINGS: Studies of antioxidant interventions in both animal and in vivo models result in reductions in serum markers of OS and increases in levels and activity of antioxidant enzymes. Antioxidant trials in PwMS, while generally underpowered, detect short-term improvements in markers of OS and antioxidant defenses, and to a lesser extent, in clinical symptoms (fatigue, depression). The best evidence to date is a 2-year trial of LA in secondary progressive MS which demonstrated a significant reduction of whole-brain atrophy and trend toward improvement in walking speed. Antioxidant therapy is a promising approach to treat MS across the spectrum and duration of disease. Rigorous and well-powered trials are needed to determine their therapeutic benefits.

Insights in pathogenesis of multiple sclerosis: nitric oxide may induce mitochondrial dysfunction of oligodendrocytes

Demyelinating diseases, such as multiple sclerosis (MS), are kinds of common diseases in the central nervous system (CNS), and originated from myelin loss and axonal damage. Oligodendrocyte dysfunction is the direct reason of demyelinating lesions in the CNS. Nitric oxide (NO) plays an important role in the pathological process of demyelinating diseases. Although the neurotoxicity of NO is more likely mediated by peroxynitrite rather than NO itself, NO can impair oligodendrocyte energy metabolism through mediating the damaging of mitochondrial DNA, mitochondrial membrane and mitochondrial respiratory chain complexes. In the progression of MS, NO can mainly mediate demyelination, axonal degeneration and cell death. Hence, in this review, we extensively discuss endangerments of NO in oligodendrocytes (OLs), which is suggested to be the main mediator in demyelinating diseases, e.g. MS. We hypothesize that NO takes part in MS through impairing the function of monocarboxylate transporter 1, especially causing axonal degeneration. Then, it further provides a new insight that NO for OLs may be a reliable therapeutic target to ameliorate the course of demyelinating diseases.

Spasticity Treatment Ameliorates the Efficacy of Melatonin Therapy in Experimental Autoimmune Encephalomyelitis (EAE) Mouse Model of Multiple Sclerosis

Multiple sclerosis (MS) is a progressive inflammatory demyelinating disease in the central nervous system (CNS). Melatonin is an effective treatment in MS patients and experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Melatonin secretion peaks at 2 AM, concomitant with the time at which the muscles are resting and the body is exerting its antioxidant activity. The current study was designed to investigate combination treatment of baclofen, a muscle relaxant drug, and melatonin in EAE mice. Results showed that melatonin (Mel) alone or in combination with baclofen (Bac + Mel) reduced clinical scores and demyelination by significantly increasing myelin oligodendrocyte glycoprotein (MOG) levels, a marker for mature oligodendrocytes, compared to EAE mice. Moreover, Mel or Bac + Mel therapy caused a significant increase in IL-4 serum levels, an anti-inflammatory cytokine, whereas IFN-γ serum levels, a pro-inflammatory cytokine, were significantly reduced. On the other hand, Mel or Bac + Mel caused a significant reduction in malondialdehyde (MDA) levels, a marker of oxidative stress, in comparison to EAE mice. In contrast, the activity of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD) was significantly increased in Mel and Bac + Mel groups. In summary, combination therapy improved clinical scores and tend to enhance the efficiency of melatonin treatment by further promoting remyelination, decreasing inflammation, and stimulating the activity of antioxidant enzymes, which suggests that prior spasticity treatment increases the efficacy of melatonin therapy in EAE mouse model of MS. Further experimental and clinical studies are needed to ensure the beneficial role of this combination strategy.

The putative interplay between DJ-1/NRF2 and Dimethyl Fumarate: A potentially important pharmacological target

Recent research has outlined that Dimethyl Fumarate (DMF) functions as a gene regulator via multiple pathways, critical among which is the NRF2 cytoprotective cascade. PARK7/DJ-1 is a multifunctional protein that acts as a redox sensor and effector of multiple cytoprotective pathways, including NRF2. Specifically, it prevents the association of NRF2 with its inhibitor KEAP1, allowing NRF2 to enter the nucleus and mediate cytoprotective and antioxidant cascades. It is our hypothesis that while the NRF2-KEAP1 inhibitory complex is reported the main pharmacological target for DMF's NRF dependent functions, no study to date has explored the effects of DMF on DJ-1's expression, and vice-versa, the possibility of a regulatory inadequacy in the upstream, oxidant-responsive DJ-1 activator of the NRF2 cascade.

Alpha-lipoic acid mitigates toxic-induced demyelination in the corpus callosum by lessening of oxidative stress and stimulation of polydendrocytes proliferation

Multiple Sclerosis (MS), is a disease that degenerates myelin in central nervous system (CNS). Reactive oxygen species (ROSs) are toxic metabolites, and accumulating data indicate that ROSs-mediated apoptosis of oligodendrocytes (OLGs) plays a major role in the pathogenesis of MS under oxidative stress conditions. In this study, we investigated the role of endogenous antioxidant alpha-lipoic acid (ALA) as ROSs scavenger in the OLGs loss and myelin degeneration during cuprizone (cup)-induced demyelination in the experimental model of MS. Our results have shown that ALA treatment significantly increased population of mature OLGs (MOG⁺ cells), as well as decreased oxidative stress (ROSs, COX-2 and PGE2) and apoptosis mediators (caspase-3 and Bax/Bcl2 ratio) in corpus callosum (CC). Surprisingly, ALA significantly stimulates population of NG2 chondroitin sulfate proteoglycan positive glia (NG2⁺ cells or polydendrocytes), from week 4 afterward. Accordingly ALA could prevents apoptosis, delays demyelination and recruits OLGs survival and regeneration mechanisms in CC. We conclude that ALA has protective effects against toxic demyelination via reduction of redox signaling, and alleviation of polydendrocytes vulnerability to excitotoxic challenge.

Modulating inflammation and neuroprotection in multiple sclerosis

Multiple sclerosis (MS) is a neurological disorder of the central nervous system with a presentation and disease course that is largely unpredictable. MS can cause loss of balance, impaired vision or speech, weakness and paralysis, fatigue, depression, and cognitive impairment. Immunomodulation is a major target given the appearance of focal demyelinating lesions in myelin-rich white matter, yet progression and an increasing appreciation for gray matter involvement, even during the earliest phases of the disease, highlights the need to afford neuroprotection and limit neurodegenerative processes that correlate with disability. This review summarizes key aspects of MS pathophysiology and histopathology with a focus on neuroimmune interactions in MS, which may facilitate neurodegeneration through both direct and indirect mechanisms. There is a focus on processes thought to influence disease progression and the role of oxidative stress and mitochondrial dysfunction in MS. The goals and efficacy of current disease-modifying therapies and those in the pipeline are discussed, highlighting recent advances in our understanding of pathways mediating disease progression to identify and translate both immunomodulatory and neuroprotective therapeutics from the bench to the clinic.

Agent based modeling of the effects of potential treatments over the blood-brain barrier in multiple sclerosis

Multiple sclerosis is a disease of the central nervous system that involves the destruction of the insulating sheath of axons, causing severe disabilities. Since the etiology of the disease is not yet fully understood, the use of novel techniques that may help to understand the disease, to suggest potential therapies and to test the effects of candidate treatments is highly advisable. To this end we developed an agent based model that demonstrated its ability to reproduce the typical oscillatory behavior observed in the most common form of multiple sclerosis, relapsing-remitting multiple sclerosis. The model has then been used to test the potential beneficial effects of vitamin D over the disease. Many scientific studies underlined the importance of the blood-brain barrier and of the mechanisms that influence its permeability on the development of the disease. In the present paper we further extend our previously developed model with a mechanism that mimics the blood-brain barrier behavior. The goal of our work is to suggest the best strategies to follow for developing new potential treatments that intervene in the blood-brain barrier. Results suggest that the best treatments should potentially prevent the opening of the blood-brain barrier, as treatments that help in recovering the blood-brain barrier functionality could be less effective.

Assessment of the Relationship Between Red Cell Distribution Width and Multiple Sclerosis

Accumulating data have shown that immune and inflammatory factors are involved in the pathogenesis of multiple sclerosis (MS), and loss of polyunsaturated fatty acids from plasma and blood cell membranes has also been reported in patients with MS, contributing to the variation of erythrocyte deformability. Therefore, the aim of this investigation was to assess the association between red blood cell distribution width (RDW) and MS. A total of 109 patients with MS and 130 healthy individuals were enrolled into the study, and MS patients receiving treatment of subcutaneous recombinant Rebif (IFN-β1a) were followed retrospectively. Complete blood cell counts and Expanded Disability Status Scale (EDSS) score were evaluated in patients with MS before and after treatment. RDW values were significantly higher in patients with MS compared with the controls (13.6 ± 0.89 vs 12.8 ± 0.38, P < 0.001); a positive correlation between RDW and EDSS score was observed in patients with MS (r = 0.789, P < 0.001). Significant differences in the value of RDW and EDSS score were observed between treatment-naive patients and treated patients (13.6 ± 0.95 vs 12.7 ± 0.44, P < 0.001; 3.6 ± 1.39 vs 1.5 ± 0.60, P < 0.001). RDW was associated independently with MS in logistic regression analysis (odds ratio = 7.007; 95% confidence interval [CI] 3.461-14.187; P < 0.001), and receiver-operating characteristics (ROC) analysis showed that a RDW measurement >13.11% evaluated MS with a sensitivity of 70.0% and a specificity of 84.7%, and the area under the ROC curve for RDW was calculated as 0.80 (95% CI 0.739-0.859, P < 0.001). The level of RDW was decreased in treatment responders with the reduction of EDSS score; a strong relationship was also observed in treatment responders between RDW and EDSS score (r = 0.733, P < 0.001), and covariance analysis indicated RDW values decreased significantly in treatment responders (P = 0.025). Our results suggest that elevated RDW values are associated with EDSS score in patients with MS, and the relationship is remarkably influenced by Rebif treatment; RDW may be a useful marker to estimate disability status and treatment effectiveness in patients with MS.

Bioenergetics profile of CD4(+) T cells in relapsing remitting multiple sclerosis subjects

Multiple sclerosis (MS) is a chronic inflammatory autoimmune demyelinating disease of the central nervous system. There are four clinical forms of MS, the most common of which is characterized by a relapsing remitting course (RRMS). The etiology of MS is unknown, but many studies suggested that genetic, environmental and infectious agents may contribute to the development of this disease. In experimental autoimmune encephalomyelitis (EAE), the animal model for MS, it has been shown that CD4(+) T cells play a key role in MS pathogenesis. In fact, these cells are able to cross the blood-brain barrier and cause axonal damage with neuronal death. T cell activation critically depends on mitochondrial ATP synthesis and reactive oxygen species (ROS) production. Interestingly, lots of studies linked the oxidative damage arising from mitochondrial changes to neurodegenerative disorders, such as MS. Based on these evidences, this work focused on the metabolic reprogramming of CD4(+) T cells in MS subjects, being this cell population directly implicated in pathogenesis of disease, paying attention to mitochondrial function and response to oxidative stress. Such aspects, once clarified, may open new opportunities for a therapeutic metabolic modulation of MS disorder.

Direct immunomodulatory influence of IFN-β on human astrocytoma cells

Astrocytes actively play a pivotal role in inflammatory disease intensity of central nervous system especially multiple sclerosis (MS). Although IFN-β is a selective therapy for MS but the role of IFN-β in stimulating the astrocytes to produce cytokines is not clearly revealed. Therefore, it is encouraging to assess the modulatory role of IFN-β on astrocytes of brain tissue. The aim of our study was to analyze the molecular mechanisms of recombinant IFN-β 1a directly affecting IL-10, iNOS, MMP-9 and TIMP-1 expression in central nervous system for the first time. In this way, in vitro procedures conducted by human astrocytoma A172 and 1321N1 cell lines as a model system. The total RNA from A172 and 1321N1 cells treated with IFN-β and LPS/IFN-γ/IFN-β and untreated cells were extracted and evaluated for IL-10, iNOS, MMP-9 and TIMP-1 expression by real-time RT-PCR. We found a significant dose-dependent increase in IL-10 gene expression in A172 and 1321N1 cells treated with IFN-β or LPS/IFN-γ/IFN-β. Moreover, a significant decrease was observed in iNOS expression suggesting a similar mechanism of action for both cells. Eventually there were no significant changes concerning the modulation of the MMP-9 and TIMP-1 in response to IFN-β treatment. In part, the immunomodulatory effect of IFN-β may be due to increase of IL-10 and suppression of iNOS expression in astrocytes of brain tissue.

Oxidative Stress and Neurobiology of Demyelination

Despite a large amount of research which aims at defining the pathophysiology of human demyelination (i.e., multiple sclerosis), etiological bases of disease have been unknown so far. The point of intersection of all assumed etiological factors, which are mainly based upon immunological cascades, is neuroinflammation. The precise definition of the place and role of all pathogenetic factors in the occurrence and development of the disease is of crucial importance for understanding the clinical nature and for finding more effective therapeutic options. There are few studies whose results give more precise data about the role and the importance of other factors in neuroinflammation, besides immunological ones, with regard to clinical and paraclinical correlates of the disease. The review integrates results found in previously performed studies which have evaluated oxidative stress participation in early and late neuroinflammation. The largest number of studies indicates that the use of antioxidants affects the change of neuroinflammation course under experimental conditions, which is reflected in the reduction of the severity and the total reversibility in clinical presentation of the disease, the faster achieving of remission, and the delayed and slow course of neuroinflammation. Therapies based on the knowledge of redox biology targeting free radical generation hold great promise in modulation of the neuroinflammation and its clinical presentations.

The therapeutic effects of MSc1 nanocomplex, synthesized by nanochelating technology, on experimental autoimmune encephalomyelitic C57/BL6 mice

Purpose

Currently approved therapies for multiple sclerosis (MS) at best only slow down its progression. Therefore, it is necessary to utilize novel technologies in order to synthesize smart multifunctional structures. In the present study, for the first time we evaluated the therapeutic potential of MSc1 nanocomplex, which was designed based on novel nanochelating technology.

Materials and methods

MSc1 cell-protection capacity, with and without iron bond, was evaluated against hydrogen peroxide (H₂O₂)-induced oxidative stress in cultured rat pheochromocytoma-12 cells. The ability of MSc1 to maintain iron bond at pH ranges of 1–7 was evaluated. Nanocomplex toxicity was examined by estimating the intraperitoneal median lethal dose (LD₅₀). Experimental autoimmune encephalomyelitic mice were injected with MSc1 14 days after disease induction, when the clinical symptoms appeared. The clinical score, body weight, and disease-induced mortality were monitored until day 54. In the end, after collecting blood samples for assessing hemoglobin and red blood cell count, the brains and livers of the mice were isolated for hematoxylin and eosin staining and analysis of iron content, respectively.

Results

The results showed that MSc1 prevented H₂O₂-induced cell death even after binding with iron, and it preserved its bond with iron constant at pH ranges 1–7. The nanocomplex intraperitoneal LD₅₀ was 1,776.59 mg/kg. MSc1 prompted therapeutic behavior and improved the disabling features of experimental autoimmune encephalomyelitis, which was confirmed by decreased clinical scores versus increased body mass and 100% survival probability. It did not cause any adverse effects on hemoglobin or red blood cell count. Histopathological studies showed no neural loss or lymphocyte infiltration in MSc1-treated mice, while the hepatic iron content was also normal.

Conclusion

These results demonstrate that MSc1 could be a promising beneficial novel agent and has the capacity to be evaluated in further studies.

The discovery and development of new potential antioxidant agents for the treatment of neurodegenerative diseases

INTRODUCTION

Several neurodegenerative disorders (NDs) including Alzheimer's and Huntington's diseases have had associations with the oxidative process and free radical damage. Consequently, in past decades, several natural and synthetic antioxidants have been assessed as therapeutic agents but have shown limitations in bioavailability, metabolic susceptibility and permeability to the blood brain barrier. Given these issues, medicinal chemists are hard at work to modify/improve the chemical structures of these antioxidants, thereby improving their efficacy.

AREAS COVERED

In this review, the authors critically analyze several biological mechanisms involved in the generation of free radicals. Additionally, they analyze free radicals' role in the generation of oxidative stress and in the progression of many NDs. Further, the authors review a collection of natural and synthetic antioxidants, their role as free radical scavengers along with their mechanisms of action and their potential for preventing neurodegenerative diseases.

EXPERT OPINION

So far, preclinical studies on several antioxidants have shown promise for treating NDs, despite their limitations. The authors do highlight the lack of the adequate animal models for preclinical assessment and this does hinder further progression into clinical trials. Further studies are necessary to fully investigate the potential of these antioxidants as ND therapeutic options.

Iron in multiple sclerosis: roles in neurodegeneration and repair

MRI and histological studies have shown global alterations in iron levels in the brains of patients with multiple sclerosis (MS), including increases in the iron stored by macrophages and microglia. Excessive free iron can be toxic, and accumulation of iron in MS has generally been thought to be detrimental. However, iron maintains the integrity of oligodendrocytes and myelin, and facilitates their regeneration following injury. The extracellular matrix, a key regulator of remyelination, might also modulate iron levels. This Review highlights key histological and MRI studies that have investigated changes in iron distribution associated with MS. Potential sources of iron, as well as iron regulatory proteins and the detrimental roles of excessive iron within the CNS, are also discussed, with emphasis on the importance of iron within cells for oxidative metabolism, proliferation and differentiation of oligodendrocytes, and myelination. In light of the beneficial and detrimental properties of iron within the CNS, we present considerations for treatments that target iron in MS. Such treatments must balance trophic and toxic properties of iron, by providing sufficient iron levels for remyelination and repair while avoiding excesses that might overwhelm homeostatic mechanisms and contribute to damage.

Synthesis and DPPH radical scavenging activity of novel compounds obtained from tyrosol and cinnamic acid derivatives

Novel compounds exhibiting DPPH radical scavenging activity were synthesised. The key step was the trifluoroacetic acid-mediated hydroarylation of cinnamic ester with tyrosol.

Mitochondrial dysfunction in demyelinating diseases

Dysfunction of the mitochondrial (mt) system is thought to play an important role in the mechanism of progression of various neurodegenerative disorders, including demyelinating disorders. They are characterized by neuroinflammation, ultimately leading to neurodegeneration. Mitochondria (mt) dysfunction is closely related to the mechanism of neuroinflammation, causing increased production of reactive oxygen species, which is detrimental to neurons and glia. Vice versa, neuroinflammation is increasingly recognized to produce mt failure, which then contributes to further neuronal injury and degeneration. Multiple sclerosis and X-linked adrenoleukodystrophy are examples of neurodemyelinating diseases that despite having a diverse etiology have in common a progressive course and significant neuroinflammation and neurodegeneration, leading to severe neurologic disability. The scientific community has become increasingly interested in how mt dysfunction relates to neuroinflammation and demyelination and what role it may play in the natural history of progressive demyelinating diseases. Research studies investigating how mt failure contributes to the progression of these conditions are emerging. A better understanding of the role of oxidative stress in progressive inflammatory demyelinating diseases might generate new potential neuroprotective therapeutic approaches for these devastating neurologic conditions.

α-Lipoic acid enhances endogenous peroxisome-proliferator-activated receptor-γ to ameliorate experimental autoimmune encephalomyelitis in mice

ALA (α-lipoic acid) is a natural, endogenous antioxidant that acts as a PPAR-γ (peroxisome-proliferator-activated receptor-γ) agonist to counteract oxidative stress. Thus far, the antioxidative and immunomodulatory effects of ALA on EAE (experimental autoimmune encephalomyelitis) are not well understood. In this study, we found that ALA restricts the infiltration of inflammatory cells into the CNS (central nervous system) in MOG (myelin oligodendrocyte glycoprotein)-EAE mice, thus reducing the disease severity. In addition, we revealed that ALA significantly suppresses the number and percentage of encephalitogenic Th1 and Th17 cells and increases splenic Treg-cells (regulatory T-cells). Strikingly, we further demonstrated that ALA induces endogenous PPAR-γ centrally and peripherally but has no effect on HO-1 (haem oxygenase 1). Together, these data suggest that ALA can up-regulate endogenous systemic and central PPAR-γ and enhance systemic Treg-cells to inhibit the inflammatory response and ameliorate MOG-EAE. In conclusion, our data provide the first evidence that ALA can augment the production of PPAR-γ in vivo and modulate adaptive immunity both centrally and peripherally in EAE and may reveal further antioxidative and immunomodulatory mechanisms for the application of ALA in human MS (multiple sclerosis).

Cerebrospinal fluid and plasma oxidative stress biomarkers in different clinical phenotypes of neuroinflammatory acute attacks. Conceptual accession: from fundamental to clinic

Oxidative stress is revealed as the main contributor in the pathophysiology of neuroinflammation. Analyzing plasma and cerebrospinal fluid (CSF) of patients with different clinical phenotypes of neuroinflammation, defined as clinically isolated syndrome (CIS), and those defined as relapsing remitting multiples sclerosis (RRMS), we tested peripheral and CNS oxidative stress intensity in these neuroinflammatory acute attacks. All obtained values changes were assessed regarding clinical and radiological features of CNS inflammation. The obtained results revealed an increase in malondialdehyde levels in plasma and CSF in CIS and RRMS patients compared to control values (p < 0.05). The obtained values were most prevailed in both study group, CIS and RRMS, in patients with severe clinical presentation (p < 0.05). Measured activities of catalase and total superoxide dismutase were higher in CIS and RRMS patients in plasma compared to control values (p < 0.05), parallel with an increased catalase activity and decrease in superoxide dismutase activity in CSF regarding values obtained in control group (p < 0.05). The positive correlations regarding clinical score were obtained for all tested biomarkers (p < 0.01). Although the positive correlations were observed in MDA levels in plasma and CSF, for both study patients, and their radiological findings (p < 0.01), and a negative correlation in plasma SOD activity and CIS patients' radiological findings (p < 0.01), no other similar correlations were obtained. These findings might be useful in providing the earliest antioxidative treatment in neuroinflammation aimed to preserve total and CNS antioxidative capacity parallel with delaying irreversible, later neurological disabilities.

Efficacy of fish oil on serum of TNF α , IL-1 β , and IL-6 oxidative stress markers in multiple sclerosis treated with interferon beta-1b

Multiple sclerosis (MS) is a chronic inflammatory disease, which leads to focal plaques of demyelination and tissue injury in the central nervous system. Oxidative stress is also thought to promote tissue damage in multiple sclerosis. Current research findings suggest that omega-3 polyunsaturated fatty acids (PUFAs) such as eicosapenta-enoic acid (EPA) and docosahexaenoic acid (DHA) contained in fish oil may have anti-inflammatory, antioxidant, and neuroprotective effects. The aim of the present work was to evaluate the efficacy of fish oil supplementation on serum proinflammatory cytokine levels, oxidative stress markers, and disease progression in MS. 50 patients with relapsing-remitting MS were enrolled. The experimental group received orally 4 g/day of fish oil for 12 months. The primary outcome was serum TNFα levels; secondary outcomes were IL-1β 1b, IL-6, nitric oxide catabolites, lipoperoxides, progression on the expanded disability status scale (EDSS), and annualized relapses rate (ARR). Fish oil treatment decreased the serum levels of TNFα, IL-1β, IL-6, and nitric oxide metabolites compared with placebo group (P ≤ 0.001). There was no significant difference in serum lipoperoxide levels during the study. No differences in EDSS and ARR were found. Conclusion. Fish oil supplementation is highly effective in reducing the levels of cytokines and nitric oxide catabolites in patients with relapsing-remitting MS.

Redox processes in neurodegenerative disease involving reactive oxygen species

Much attention has been devoted to neurodegenerative diseases involving redox processes. This review comprises an update involving redox processes reported in the considerable literature in recent years. The mechanism involves reactive oxygen species and oxidative stress, usually in the brain. There are many examples including Parkinson’s, Huntington’s, Alzheimer’s, prions, Down’s syndrome, ataxia, multiple sclerosis, Creutzfeldt-Jacob disease, amyotrophic lateral sclerosis, schizophrenia, and Tardive Dyskinesia. Evidence indicates a protective role for antioxidants, which may have clinical implications. A multifaceted approach to mode of action appears reasonable.

The patients with clinically isolated syndrome and relapsing remitting multiple sclerosis show different levels of advanced protein oxidation products and total thiol content in plasma and CSF

Advanced oxidation protein products (AOPP) and total thiol (SH) groups levels in plasma and CSF were studied in a cohort of 50 clinically isolated syndrome (CIS) and 57 relapsing remittent multiple sclerosis (RRMS) patients related to 20 control group (CG) patients' values. The obtained results were compared regarding patients demographic, biochemical, clinical (EDSS) and MRI features (total T2 weighted lesions number and Gd enhancement lesion volume). Plasma and CSF AOPP levels in CIS and RRMS patients were higher than those in CG, while SH groups showed lower values compared to CG (p<0.05). Both parameters were higher in CIS than in RRMS patients (p<0.05). Related to EDSS median range, all patients were divided into those with slight or mild and those with severe clinical presentation. AOPP and SH group changes were more pronounced in both, CIS and RRMS patients with higher, compared to those with lower EDSS (p<0.05). AOPP, SH group levels and EDSS positive correlations were observed in both study groups (p<0.01). Both parameters showed the same approach regarding the median range of total T2 weighted lesions and Gd enhancement lesion volume mean values (p<0.05), but no correlation was found between AOPP and SH levels and these patients radiological characteristics (p>0.01). The data support the fact that oxidative stress is always involved in CIS and RRMS pathophysiology, but not always as a disease determinant dependent on its intensity, which might be important for new therapeutic strategies based on antioxidant approach in those patients.

The role of reactive oxygen species and proinflammatory cytokines in type 1 diabetes pathogenesis

Type 1 diabetes (T1D) is a T cell–mediated autoimmune disease characterized by the destruction of insulin-secreting pancreatic β cells. In humans with T1D and in nonobese diabetic (NOD) mice (a murine model for human T1D), autoreactive T cells cause β-cell destruction, as transfer or deletion of these cells induces or prevents disease, respectively. CD4⁺ and CD8⁺ T cells use distinct effector mechanisms and act at different stages throughout T1D to fuel pancreatic β-cell destruction and disease pathogenesis. While these adaptive immune cells employ distinct mechanisms for β-cell destruction, one central means for enhancing their autoreactivity is by the secretion of proinflammatory cytokines, such as IFN-γ, TNF-α, and IL-1. In addition to their production by diabetogenic T cells, proinflammatory cytokines are induced by reactive oxygen species (ROS) via redox-dependent signaling pathways. Highly reactive molecules, proinflammatory cytokines are produced upon lymphocyte infiltration into pancreatic islets and induce disease pathogenicity by directly killing β cells, which characteristically possess low levels of antioxidant defense enzymes. In addition to β-cell destruction, proinflammatory cytokines are necessary for efficient adaptive immune maturation, and in the context of T1D they exacerbate autoimmunity by intensifying adaptive immune responses. The first half of this review discusses the mechanisms by which autoreactive T cells induce T1D pathogenesis and the importance of ROS for efficient adaptive immune activation, which, in the context of T1D, exacerbates autoimmunity. The second half provides a comprehensive and detailed analysis of (1) the mechanisms by which cytokines such as IL-1 and IFN-γ influence islet insulin secretion and apoptosis and (2) the key free radicals and transcription factors that control these processes.

Evaluation of serum oxidant/antioxidant balance in multiple sclerosis

The total oxidative status (TOS)/total anti-oxidative status (TAS) ratio can provide information on an individual's absolute oxidative stress index (OSI). We investigated the alterations in the oxidant-antioxidant balance by measuring the oxidant parameters OSI, TOS, and malondialdehyde (MDA) together with the antioxidant parameters such as TAS, and superoxide dismutase (SOD) in patients with relapsing remitting multiple sclerosis (MS). To our knowledge, this is the first study to evaluate OSI in patients with relapsing remitting MS. 35 ambulatory patients with relapsing-remitting MS (35.8 ± 8.7 years) and 32 age- and activity-matched healthy control subjects (35.1 ± 3.7 years) that participated in the study. Serum TAS and TOS levels were determined using new automated methods. MS patients had higher concentrations of MDA (151.5 ± 51.1 vs. 111.3 ± 27.4 nmol/g protein, respectively; p < 0.001), TOS (148.1 ± 162.5 vs. 48.3 ± 46.4 mmol H(2)O(2) Equiv./g protein, respectively; p = 0.002), OSI (21124 ± 32543 vs. 5294 ± 5562, respectively; p = 0.008), and SOD (4.5 ± 0.7 vs. 3.4 ± 0.6 U/L, respectively; p < 0.001) compared with healthy controls. On the other hand, MS patients had lower concentrations of NO (12.3 ± 6.9 vs. 17.4 ± 2.5 μmol/g protein, respectively; p < 0.001) and TAS (0.82 ± 0.27 vs. 0.26 ± 0.15, respectively; p = 0.011) compared with healthy controls. In conclusion, these findings indicate that the oxidative stress plays an important role in the pathogenesis of MS.

NOX2 complex-derived ROS as immune regulators

Reactive oxygen species (ROS) are a heterogeneous group of highly reactive molecules that oxidize targets in a biologic system. During steady-state conditions, ROS are constantly produced in the electron-transport chain during cellular respiration and by various constitutively active oxidases. ROS production can also be induced by activation of the phagocyte NADPH oxidase 2 (NOX2) complex in a process generally referred to as an oxidative burst. The induced ROS have long been considered proinflammatory, causing cell and tissue destruction. Recent findings have challenged this inflammatory role of ROS, and today, ROS are also known to regulate immune responses and cell proliferation and to determine T-cell autoreactivity. NOX2-derived ROS have been shown to suppress antigen-dependent T-cell reactivity and remarkably to reduce the severity of experimental arthritis in both rats and mice. In this review, we discuss the role of ROS and the NOX2 complex as suppressors of autoimmunity, inflammation, and arthritis.

Tight junctions in brain barriers during central nervous system inflammation

Homeostasis within the central nervous system (CNS) is a prerequisite to elicit proper neuronal function. The CNS is tightly sealed from the changeable milieu of the blood stream by the blood-brain barrier (BBB) and the blood-cerebrospinal fluid (CSF) barrier (BCSFB). Whereas the BBB is established by specialized endothelial cells of CNS microvessels, the BCSFB is formed by the epithelial cells of the choroid plexus. Both constitute physical barriers by a complex network of tight junctions (TJs) between adjacent cells. During many CNS inflammatory disorders, such as multiple sclerosis, human immunodeficiency virus infection, or Alzheimer's disease, production of pro-inflammatory cytokines, matrix metalloproteases, and reactive oxygen species are responsible for alterations of CNS barriers. Barrier dysfunction can contribute to neurological disorders in a passive way by vascular leakage of blood-borne molecules into the CNS and in an active way by guiding the migration of inflammatory cells into the CNS. Both ways may directly be linked to alterations in molecular composition, function, and dynamics of the TJ proteins. This review summarizes current knowledge on the cellular and molecular aspects of the functional and dysfunctional TJ complexes at the BBB and the BCSFB, with a particular emphasis on CNS inflammation and the role of reactive oxygen species.