There is increasing awareness of the ubiquitous role of oxidative stress in neurodegenerative disease states. A continuing challenge is to be able to distinguish between oxidative changes that occur early in the disease from those that are secondary manifestations of neuronal degeneration. This perspective highlights the role of oxidative stress in Alzheimer’s, Parkinson’s, and Huntington’s diseases, amyotrophic lateral sclerosis, and multiple sclerosis, neurodegenerative and neuroinflammatory disorders where there is evidence for a primary contribution of oxidative stress in neuronal death, as opposed to other diseases where oxidative stress more likely plays a secondary or by-stander role. We begin with a brief review of the biochemistry of oxidative stress as it relates to mechanisms that lead to cell death, and why the central nervous system is particularly susceptible to such mechanisms. Following a review of oxidative stress involvement in individual disease states, some conclusions are provided as ...

https://pubs.acs.org/doi/pdf/10.1021/tx700210j

Oxidative stress and neurotoxicity

Accumulating data indicate that oxidative stress (OS) plays a major role in the pathogenesis of multiple sclerosis (MS). Reactive oxygen species (ROS), leading to OS, generated in excess primarily by macrophages, have been implicated as mediators of demyelination and axonal damage in both MS and experimental autoimmune encephalomyelitis (EAE), its animal model. ROS cause damage to cardinal cellular components such as lipids, proteins and nucleic acids (e. g., RNA, DNA), resulting in cell death by necrosis or apoptosis. In addition, weakened cellular antioxidant defense systems in the central nervous system (CNS) in MS, and its vulnerability to ROS effects may increase damage. Thus, treatment with antioxidants might theoretically prevent propagation of tissue damage and improve both survival and neurological outcome. Indeed, several experimental studies have been performed to see whether dietary intake of several antioxidants prevents or reduces the progression of EAE. Although a few antioxidants showed some efficacy in these studies, little information is available on the effect of treatments with such compounds in patients with MS. Well-designed clinical studies using antioxidant intake, as well as investigations based on larger cohorts studied over a longer periods of time, are needed in order to assess whether antioxidant intake together with other conventional treatments, might be beneficial in treating MS.

The role of oxidative stress in the pathogenesis of multiple sclerosis: the need for effective antioxidant therapy.

Over the past three decades, selenium has been intensively investigated as an antioxidant trace element. It is widely distributed throughout the body, but is particularly well maintained in the brain, even upon prolonged dietary selenium deficiency. Changes in selenium concentration in blood and brain have been reported in Alzheimer's disease and brain tumors. The functions of selenium are believed to be carried out by selenoproteins, in which selenium is specifically incorporated as the amino acid, selenocysteine. Several selenoproteins are expressed in brain, but many questions remain about their roles in neuronal function. Glutathione peroxidase has been localized in glial cells, and its expression is increased surrounding the damaged area in Parkinson's disease and occlusive cerebrovascular disease, consistent with its protective role against oxidative damage. Selenoprotein P has been reported to possess antioxidant activities and the ability to promote neuronal cell survival. Recent studies in cell culture and gene knockout models support a function for selenoprotein P in delivery of selenium to the brain. mRNAs for other selenoproteins, including selenoprotein W, thioredoxin reductases, 15-kDa selenoprotein and type 2 iodothyronine deiodinase, are also detected in the brain. Future research directions will surely unravel the important functions of this class of proteins in the brain.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1471-4159.2003.01854.x

Selenium and selenoproteins in the brain and brain diseases

This review highlights the role of oxidative stress and imbalances in metal ion homeostasis in the neurodegenerative diseases Alzheimer's disease and Parkinson's disease and in the progressive demyelinating disease multiple sclerosis. The chemistry and biochemistry of oxidative stress-induced protein damage are first described, followed by the evidence for a pathological role of oxidative stress in these disease states. It is tempting to speculate that free radical oxygen chemistry contributes to pathogenesis in all these conditions, though it is as yet undetermined what types of oxidative changes occur early in the disease, and what types are secondary manifestations of neuronal degeneration.

Metal ions and oxidative protein modification in neurological disease

A chronic inflammatory disease is a condition characterized by persistent inflammation. A number of human pathologies fall into this category, and a great deal of research has been conducted to learn more about their characteristics and underlying mechanisms. In many cases, a genetic component has been identified, but also external factors like food, smoke, or environmental pollutants can significantly contribute to worsen their symptoms. Accumulated evidence clearly shows that chronic inflammatory diseases are subjected to a redox control. Here, we shall review the identity, source, regulation, and biological activity of redox molecules, to put in a better perspective their key-role in cancer, diabetes, cardiovascular diseases, atherosclerosis, chronic obstructive pulmonary diseases, and inflammatory bowel diseases. In addition, the impact of redox species on autoimmune disorders (rheumatoid arthritis, systemic lupus erythematosus, psoriasis, and celiac disease) and neurodegenerative diseases (A...

Chronic inflammatory disorders and their redox control: from molecular mechanisms to therapeutic opportunities.

It is well known that brain and nervous system cells are prone to oxidative damage because of their relatively low content of antioxidants, especially enzymatic ones, and of the high levels of both membrane polyunsaturated fatty acids (PUFA) and iron easily released from injured cells. We have investigated the oxidative stress in the blood (plasma, erythrocytes and lymphocytes) of 28 patients affected with multiple sclerosis (MS) and of 30 healthy age matched controls, by performing a multiparameter analysis of non-enzymatic and enzymatic antioxidants--Vitamin E (Vit. E), ubiquinone (UBI), reduced and oxidized glutathione (GSH, GS-SG), superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and fatty acid patterns of phospholipids (PL-FA). PL-FA and Vit. E were assayed by GC-MS; UBI and GSH/GS-SG by HPLC; SOD, GPX and CAT by spectrophotometry. In comparison to controls, patients with MS showed significantly reduced levels of plasma UBI (0.21 +/- 0.10 vs. 0.78 +/- 0.08 mg/ml, p < 0.001), plasma Vit. E (7.4 +/- 2.1 vs. 11.4 +/- 1.8 mg/ml, p < 0.01), lymphocyte UBI (8.1 +/- 4.0 vs. 30.3 +/- 7.2 ng/ml blood, p < 0.001) and erythrocyte GPX (22.6 +/- 5.7 vs. 36.3 +/- 6.4 U/g Hb, p < 0.001). This blood antioxidant deficiency was associated with plasma levels of PL-PUFA--especially C20:3 n-6 and C20:4 n-6--significantly higher than controls. In conclusion, the blood of patients with MS shows the signs of a significant oxidative stress. The possibility of counteracting it by antioxidant administration plus an appropriate diet, might represent a promising way of inhibiting the progression of the disease. Antioxidant supplements should include not only GSH repleting agents, but also Vit. E, ubiquinol, and selenium.

C Syburra

Papers

Oxidative stress in patients with multiple sclerosis.