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1.
[Selenium and zinc: "antioxidants" for healthy aging?].
Steinbrenner, H, Klotz, LO
Zeitschrift fur Gerontologie und Geriatrie. 2020;(4):295-302
Abstract
Selenium and zinc are essential trace elements and an inadequate dietary intake has been implicated in the decline of immune and cognitive functions in aged persons and in the pathogenesis of age-related disorders. Both micronutrients are often marketed as "antioxidants" in mineral supplements; however, neither selenium nor zinc are antioxidants per se but they may exert beneficial effects as components of enzymes and other proteins that catalyze redox reactions and/or are involved in the maintenance of redox homeostasis. According to epidemiological data older individuals have an increased risk of developing deficiencies in the selenium and zinc status; however, such statistical correlations in epidemiological studies do not imply a causal association. Intervention trials are scarce and have yielded inconsistent and sometimes even adverse results. It should also be noted that the observed deficiencies in micronutrients may not necessarily be attributable to inadequate dietary intake as the absorption and distribution within the body might also be influenced by factors such as medications or interaction with other food ingredients. Thus, any dietary supplementation should be implemented with caution and persons who wish to take mineral supplements should first seek medical advice. This article discusses the role of selenium and zinc in biological antioxidant systems, summarizes findings on the supply and supplementation of aged persons with these trace elements and on the influence they may exert on aging-related health issues, such as cognitive decline and type 2 diabetes mellitus.
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2.
Role of Oxidative Stress and Antioxidants in Autism.
Manivasagam, T, Arunadevi, S, Essa, MM, SaravanaBabu, C, Borah, A, Thenmozhi, AJ, Qoronfleh, MW
Advances in neurobiology. 2020;:193-206
Abstract
Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental disorders with poorly understood etiology that are defined exclusively on the basis of behavioral observations. This disorder has been linked to increased levels of oxidative stress and lower antioxidant capacity. Oxidative stress in autism has been studied at the membrane level and also by measuring products of lipid peroxidation, detoxifying agents (such as glutathione), and antioxidants involved in the defense system against reactive oxygen species (ROS). Several studies have suggested alterations in the activities of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and catalase in autism. Additionally, altered glutathione levels and homocysteine/methionine metabolism, increased inflammation, excitotoxicity, as well as mitochondrial and immune dysfunction have been suggested in autism. Moreover, environmental and genetic risk factors may intensify vulnerability to oxidative stress in autism. Collectively, these studies suggest increased oxidative stress in autism that may contribute to the development of this disease both in terms of pathogenesis and clinical symptoms. Antioxidant supplementation, or ways to improve the altered metabolite levels in the interconnected transmethylation and transsulfuration pathways, has been associated with decreased autistic behaviors and severity. This chapter provides a conceptual framework on oxidative stress and antioxidants utility. These types of interventions should be further studied in order to determine their effectiveness at improving metabolic imbalances.
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3.
Grapevine as a Rich Source of Polyphenolic Compounds.
Šikuten, I, Štambuk, P, Andabaka, Ž, Tomaz, I, Marković, Z, Stupić, D, Maletić, E, Kontić, JK, Preiner, D
Molecules (Basel, Switzerland). 2020;(23)
Abstract
Grapes are rich in primary and secondary metabolites. Among the secondary metabolites, polyphenolic compounds are the most abundant in grape berries. Besides their important impacts on grape and wine quality, this class of compounds has beneficial effects on human health. Due to their antioxidant activity, polyphenols and phenolic acids can act as anti-inflammatory and anticancerogenic agents, and can modulate the immune system. In grape berries, polyphenols and phenolic acids can be located in the pericarp and seeds, but distribution differs considerably among these tissues. Although some classes of polyphenols and phenolic acids are under strict genetic control, the final content is highly influenced by environmental factors, such as climate, soil, vineyard, and management. This review aims to present the main classes of polyphenolic compounds and phenolic acids in different berry tissues and grape varieties and special emphasis on their beneficial effect on human health.
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4.
Research progress on the biological activities of selenium polysaccharides.
Zhou, N, Long, H, Wang, C, Yu, L, Zhao, M, Liu, X
Food & function. 2020;(6):4834-4852
Abstract
Selenium polysaccharides are a new type of functional polysaccharide that combines inorganic selenium with polysaccharides to form an organic selenium product. Selenium polysaccharides are obtained using three different methods, have no toxicity or side effects, and are easily absorbed and utilized by the body. A number of studies have demonstrated that selenium polysaccharides possess better antioxidant, antitumour, immune regulation, hypoglycaemic, and heavy metal removal activities than that of either polysaccharides or inorganic selenium. Selenium polysaccharides have gradually become a research topic of interest for the development of functional foods and pharmaceutical products. However, further studies are required to investigate the structures and mechanisms of selenium polysaccharides. At present, reviews that focus on the bioactivities of selenium polysaccharides are lacking. The aim of this study was to summarize the selenium polysaccharide bioactivity reports from the past decades, describe the mechanisms and shortcomings of these studies, and evaluate the need for further development.
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5.
Rationale for the use of N-acetylcysteine in both prevention and adjuvant therapy of COVID-19.
De Flora, S, Balansky, R, La Maestra, S
FASEB journal : official publication of the Federation of American Societies for Experimental Biology. 2020;(10):13185-13193
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Abstract
COVID-19 may cause pneumonia, acute respiratory distress syndrome, cardiovascular alterations, and multiple organ failure, which have been ascribed to a cytokine storm, a systemic inflammatory response, and an attack by the immune system. Moreover, an oxidative stress imbalance has been demonstrated to occur in COVID-19 patients. N- Acetyl-L-cysteine (NAC) is a precursor of reduced glutathione (GSH). Due to its tolerability, this pleiotropic drug has been proposed not only as a mucolytic agent, but also as a preventive/therapeutic agent in a variety of disorders involving GSH depletion and oxidative stress. At very high doses, NAC is also used as an antidote against paracetamol intoxication. Thiols block the angiotensin-converting enzyme 2 thereby hampering penetration of SARS-CoV-2 into cells. Based on a broad range of antioxidant and anti-inflammatory mechanisms, which are herein reviewed, the oral administration of NAC is likely to attenuate the risk of developing COVID-19, as it was previously demonstrated for influenza and influenza-like illnesses. Moreover, high-dose intravenous NAC may be expected to play an adjuvant role in the treatment of severe COVID-19 cases and in the control of its lethal complications, also including pulmonary and cardiovascular adverse events.
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Devilishly radical NETwork in COVID-19: Oxidative stress, neutrophil extracellular traps (NETs), and T cell suppression.
Schönrich, G, Raftery, MJ, Samstag, Y
Advances in biological regulation. 2020;:100741
Abstract
Pandemic coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and poses an unprecedented challenge to healthcare systems due to the lack of a vaccine and specific treatment options. Accordingly, there is an urgent need to understand precisely the pathogenic mechanisms underlying this multifaceted disease. There is increasing evidence that the immune system reacts insufficiently to SARS-CoV-2 and thus contributes to organ damage and to lethality. In this review, we suggest that the overwhelming production of reactive oxygen species (ROS) resulting in oxidative stress is a major cause of local or systemic tissue damage that leads to severe COVID-19. It increases the formation of neutrophil extracellular traps (NETs) and suppresses the adaptive arm of the immune system, i.e. T cells that are necessary to kill virus-infected cells. This creates a vicious cycle that prevents a specific immune response against SARS-CoV-2. The key role of oxidative stress in the pathogenesis of severe COVID-19 implies that therapeutic counterbalancing of ROS by antioxidants such as vitamin C or NAC and/or by antagonizing ROS production by cells of the mononuclear phagocyte system (MPS) and neutrophil granulocytes and/or by blocking of TNF-α can prevent COVID-19 from becoming severe. Controlled clinical trials and preclinical models of COVID-19 are needed to evaluate this hypothesis.
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Effects of vitamin E incorporation in polyethylene on oxidative degradation, wear rates, immune response, and infections in total joint arthroplasty: a review of the current literature.
Lambert, B, Neut, D, van der Veen, HC, Bulstra, SK
International orthopaedics. 2019;(7):1549-1557
Abstract
Highly cross-linked ultrahigh molecular weight polyethylene (UHMWPE) was introduced to decrease wear debris and osteolysis. During cross-linking, free radicals are formed, making highly cross-linked polyethylene vulnerable to oxidative degradation. In order to reduce this process, anti-oxidant vitamin E can be incorporated in polyethylene. This review provides an overview of the effects of vitamin E incorporation on major complications in total joint arthroplasty: material failure due to oxidative degradation, wear debris and subsequent periprosthetic osteolysis, and prosthetic joint infections. Secondly, this review summarizes the first clinical results of total hip and knee arthroplasties with vitamin E incorporated highly cross-linked polyethylene. Based on in vitro studies, incorporation of vitamin E in polyethylene provides good oxidative protection and preserves low wear rates. Incorporation of vitamin E may have the beneficial effect of reduced inflammatory response to its wear particles. Some microorganisms showed reduced adherence to vitamin E-incorporated UHMWPE; however, clinical relevance is doubtful. Short-term clinical studies of total hip and knee arthroplasties with vitamin E-incorporated highly cross-linked UHMWPE reported good clinical results and wear rates similar to highly cross-linked UHMWPE without vitamin E.
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8.
Role of Zinc in Immune System and Anti-Cancer Defense Mechanisms.
Skrajnowska, D, Bobrowska-Korczak, B
Nutrients. 2019;(10)
Abstract
The human body cannot store zinc reserves, so a deficiency can arise relatively quickly, e.g., through an improper diet. Severe zinc deficiency is rare, but mild deficiencies are common around the world. Many epidemiological studies have shown a relationship between the zinc content in the diet and the risk of cancer. The anti-cancer effect of zinc is most often associated with its antioxidant properties. However, this is just one of many possibilities, including the influence of zinc on the immune system, transcription factors, cell differentiation and proliferation, DNA and RNA synthesis and repair, enzyme activation or inhibition, the regulation of cellular signaling, and the stabilization of the cell structure and membranes. This study presents selected issues regarding the current knowledge of anti-cancer mechanisms involving this element.
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The controversial role of vitamin D as an antioxidant: results from randomised controlled trials.
Tagliaferri, S, Porri, D, De Giuseppe, R, Manuelli, M, Alessio, F, Cena, H
Nutrition research reviews. 2019;(1):99-105
Abstract
Increased oxidative stress has been implicated as a potential causal factor in the development of several diseases. In the last decade, an extensive literature has been produced on vitamin D, not limited to its well-known function like a steroid hormone on skeletal tissue, but for its potential pleiotropic role in human health. Several researchers have suggested relationships between vitamin D intake and health outcomes such as cancer prevention and increased immunity, or possible role in preventing diabetes, and in inflammation. Little is known about its antioxidant effect. The aim of the present review was to explore major evidence regarding the potential scavenger capacity of vitamin D in high-evidence human studies. Studies considered by the present review suggest that the potential role of vitamin D as an antioxidant could not be confirmed. Current literature showed controversial effects about the ability of cholecalciferol to prevent or ameliorate oxidative stress biomarkers, and there is need of further and high-quality studies testing the antioxidant effect of vitamin D supplementation.
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10.
The Link Between Selenium, Oxidative Stress and Pregnancy Induced Hypertensive Disorders.
Bizerea, TO, Dezsi, SG, Marginean, O, Stroescu, R, Rogobete, A, Bizerea-Spiridon, O, Ilie, C
Clinical laboratory. 2018;(10):1593-1610
Abstract
BACKGROUND The first line of defence against oxidative stress (OS) are the endogenous antioxidants, such as the Se containing compounds. During pregnancy, OS is caused by the intense growth activity of the fetus; therefore, the placenta is a key place for the activity of many seleno-compounds such as glutathione-peroxidase and thioredoxinreductase. METHODS This review aims to establish the link between the type of selenium compounds, their concentration, their metabolic pathways, and their role in both physiologic and pathologic processes during pregnancy. RESULTS A review of current literature establishes that Se containing compounds have a strong antioxidant effect. The limits that define deviations from the normal concentration range of selenium are very close. Both selenium deficiency and excess have an effect on human health. It is well known that oxidative stress, namely the increase in the concentration of reactive species of oxygen and nitrogen (ROS and RNS) and the disruption of cellular redox homeostasis, are responsible for a number of inflammatory, degenerative, autoimmune, and neoplastic diseases. Selenium deficiency in the pregnant woman's body is considered a risk factor for immune deficiency, PIH, spontaneous abortions, and premature birth. In regard to the fetus, while there seems to be a certain protection against selenium-induced toxicity, studies have shown that selenium defficiency leads to IUGR and SGA newborns. Also, combined deficiency of selenium and iodine has been linked to endemic cretinism in newborns. CONCLUSIONS The antioxidant role that selenium performs through selenoproteins is major. Selenium-containing proteins, especially glutathione peroxidase, as antioxidant enzymes, are involved in regulating the ROS and RNS levels and redox balancing in almost all tissues. Among the multiple benefits of selenium in optimal concentrations in the body are stimulation and support of female fertility, as well as good development of the fetus. Hypertensive pathologies that occur in one of ten pregnant women, especially during the second part of the gestation period, are largely due to selenium deficiency.