Tolerability and Safety of Combined Glatiramer Acetate and N-Acetylcysteine in Relapsing-Remitting Multiple Sclerosis

Effects of N-acetylcysteine on oxidative stress biomarkers, depression, and anxiety symptoms in patients with multiple sclerosis

AIM

N-acetylcysteine (NAC), a thiol-containing antioxidant and glutathione (GSH) precursor, attenuates oxidative stress, and possibly improves psychiatric disorders. This study aimed to evaluate the effects of oral NAC on oxidative stress, depression, and anxiety symptoms in patients with multiple sclerosis (MS).

METHODS

This clinical trial was conducted on 42 MS patients randomly assigned to intervention (n = 21) and control (n = 21) groups. The intervention group received 600 mg of NAC twice daily for 8 weeks, and the control group received a placebo with the same prescription form. An analysis of serum malondialdehyde (MDA), serum nitric oxide (NO), and erythrocyte GSH was carried out on both groups, along with a complete blood count. The Hospital Anxiety and Depression Scale (HADS) was used to assess symptoms of depression (HADS-D) and anxiety (HADS-A).

RESULTS

Compared to the control group, NAC consumption significantly decreased serum MDA concentrations (-0.33 [-5.85-2.50] vs. 2.75 [-0.25-5.22] μmol/L; p = 0.03) and HADS-A scores (-1.6 ± 2.67 vs. 0.33 ± 2.83; p = 0.02). No significant changes were observed in serum NO concentrations, erythrocyte GSH levels, and HADS-D scores (p > 0.05).

CONCLUSIONS

Based on the findings of the present study, NAC supplementation for 8 weeks decreased lipid peroxidation and improved anxiety symptoms in MS patients. The aforementioned results suggest that adjunctive therapy with NAC can be considered an effective strategy for MS management. Further randomized controlled studies are warranted.

The Post-Translational Modifications of Human Salivary Peptides and Proteins Evidenced by Top-Down Platforms

In this review, we extensively describe the main post-translational modifications that give rise to the multiple proteoforms characterized to date in the human salivary proteome and their potential role. Most of the data reported were obtained by our group in over twenty-five years of research carried out on human saliva mainly by applying a top-down strategy. In the beginning, we describe the products generated by proteolytic cleavages, which can occur before and after secretion. In this section, the most relevant families of salivary proteins are also described. Next, we report the current information concerning the human salivary phospho-proteome and the limited news available on sulfo-proteomes. Three sections are dedicated to the description of glycation and enzymatic glycosylation. Citrullination and N- and C-terminal post-translational modifications (PTMs) and miscellaneous other modifications are described in the last two sections. Results highlighting the variation in the level of some proteoforms in local or systemic pathologies are also reviewed throughout the sections of the manuscript to underline the impact and relevance of this information for the development of new diagnostic biomarkers useful in clinical practice.

A pilot study of oxidative pathways in MS fatigue: randomized trial of N-acetyl cysteine

Objective

To assess feasibility, tolerability, and safety of N‐acetyl cysteine (NAC) for fatigue in progressive MS. Secondary objectives evaluated changes in fatigue and oxidative pathway biomarkers on NAC versus placebo.

Methods

Individuals with progressive MS with Modified Fatigue Impact Scale (MFIS) > t38 were randomized 2:1 to NAC 1250mg TID or placebo for 4 weeks. The primary outcome was tolerability and safety. The secondary outcome to evaluate efficacy was MFIS change from baseline to week 4 between groups. Exploratory biomarker outcomes included change in blood GSH/GSSG ratio (reduced‐to‐oxidized glutathione (GSH)) and in vivo relative GSH using 7T MR spectroscopy (MRS) between groups. Fisher exact test was used for categorical and rank sum for continuous outcomes.

Results

Fifiteen were randomized (10 NAC, 5 placebo; mean age 56.1 years, 80% female, median EDSS 6.0). At least one adverse event (AE) occurred in 60% on NAC versus 80% on placebo (p = 0.75). There were two AEs attributed to NAC in one patient (abdominal pain and constipation), with 94% adherence to NAC. MFIS decreased in both groups at week 4, with the mean improvement of 11‐points on NAC versus 18‐points on placebo (p = 0.33). GSH/GSSG ratio decreased on placebo (−0.6) and NAC (−0.1) (p = 0.18). Change in GSH levels to total creatine in anterior and posterior cingulate cortex, insula, caudate, putamen, and thalamus did not differ between groups.

Interpretation

NAC was well‐tolerated in progressive MS, although reduction in fatigue on NAC was similar to placebo. Antioxidant blood and MRS biomarkers were not significantly altered by NAC, which could be due to dose, route of administration, time of sample collection, short half‐life, or lack of effect.

Registered

clinicaltrials.gov NCT02804594.

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.

Top-down proteomic profiling of human saliva in multiple sclerosis patients

Multiple sclerosis is a chronic disease of the central nervous system characterized by inflammation, demyelination and neurodegeneration which is of undetermined origin. To date a single diagnostic test of multiple sclerosis does not exists and novel biomarkers are demanded for a more accurate and early diagnosis. In this study, we performed the quantitative analysis of 119 salivary peptides/proteins from 49 multiple sclerosis patients and 54 healthy controls by a mass spectrometry-based top-down proteomic approach. Statistical analysis evidenced different levels on 23 proteins: 8 proteins showed lower levels in multiple sclerosis patients with respect to controls and they were mono- and di-oxidized cystatin SN, mono- and di-oxidized cystatin S1, mono-oxidized cystatin SA and mono-phosphorylated statherin. 15 proteins showed higher levels in multiple sclerosis patients with respect to controls and they were antileukoproteinase, two proteoforms of Prolactin-Inducible Protein, P-C peptide (Fr.1-14, Fr. 26-44, and Fr. 36-44), SV1 fragment of statherin, cystatin SN Des_1-4, cystatin SN P₁₁ → L variant, and cystatin A T₉₆ → M variant. The differences observed between the salivary proteomic profile of patients suffering from multiple sclerosis and healthy subjects is consistent with the inflammatory condition and altered immune response typical of the pathology. Data are available via ProteomeXchange with identifier PXD009440.

SIGNIFICANCE

To date a single diagnostic test of multiple sclerosis does not exist, and diagnosis is based on multiple tests which mainly include the analysis of cerebrospinal fluid. However, the need for lumbar puncture makes the analysis of cerebrospinal fluid impractical for monitoring disease activity and response to treatment. The possible use of saliva as a diagnostic fluid for oral and systemic diseases has been largely investigated, but only marginally in multiple sclerosis compared to other body fluids. Our study demonstrates that the salivary proteome of multiple sclerosis patients differs considerably compared to that of sex and age matched healthy individuals and suggests that some differences might be associated with the different disease-modifying therapy used to treat multiple sclerosis patients.

Dose-dependent S-allyl cysteine ameliorates multiple sclerosis disease-related pathology by reducing oxidative stress and biomarkers of dysbiosis in experimental autoimmune encephalomyelitis

Garlic is a component of the Mediterranean diet. S-allyl cysteine (SAC), the most common organosulphur present in garlic, possesses neuroprotective properties. This investigation was performed to evaluate the dose-dependent protective action of SAC on oxidative damage, inflammation and gut microbiota alterations biomarkers. Experimental autoimmune encephalomyelitis (EAE) as a model of multiple sclerosis (MS) was induced by the myelin oligodendrocyte glycoprotein (MOG), whose effects were quantified by examining the changes in: clinical score, lipid peroxidation products, carbonylated proteins, glutathione system, tumor necrosis factor alpha (TNFα), and lipopolysaccharide membrane bacteria (LPS). Our results reveal that MOG induces paralysis, oxidative damage and increases in LPS binding protein (LBP) and LPS levels. In this work, two doses of SAC were compared with two dose of N-acetyl cysteine (NAC). SAC was more effective than NAC and it prevented the harmful effects induced by MOG more effectively at the dose of 50mg/kg than that of 18mg/kg. Surprisingly, NAC increases LBP levels while SAC had not such negative effect. In conclusion the data show the ability of SAC to modify EAE evolution.

New Insights into the Role of Oxidative Stress Mechanisms in the Pathophysiology and Treatment of Multiple Sclerosis

Multiple sclerosis (MS) is a multifactorial disease of the central nervous system (CNS) characterized by an inflammatory process and demyelination. The etiology of the disease is still not fully understood. Therefore, finding new etiological factors is of such crucial importance. It is suspected that the development of MS may be affected by oxidative stress (OS). In the acute phase OS initiates inflammatory processes and in the chronic phase it sustains neurodegeneration. Redox processes in MS are associated with mitochondrial dysfunction, dysregulation of axonal bioenergetics, iron accumulation in the brain, impaired oxidant/antioxidant balance, and OS memory. The present paper is a review of the current literature about the role of OS in MS and it focuses on all major aspects. The article explains the mechanisms of OS, reports unique biomarkers with regard to their clinical significance, and presents a poorly understood relationship between OS and neurodegeneration. It also provides novel methods of treatment, including the use of antioxidants and the role of antioxidants in neuroprotection. Furthermore, adding new drugs in the treatment of relapse may be useful. The article considers the significance of OS in the current treatment of MS patients.