scholarly journals Endogenous Enzymatic Antioxidant Defense and Pathologies

2021 ◽  
Author(s):  
Atika Eddaikra ◽  
Naouel Eddaikra

Oxidative stress is an important component of various diseases. It manifests as an imbalance caused by an excessive production of reactive oxygen species (ROS) which are associated with a deficit of antioxidant activity. This deficit can be the consequence of genetic factors, environmental ones, metabolic imbalance, toxicity or direct attacks by the accumulation of free radicals. These can induce metabolic dysfunction affecting biological macromolecules in their structures or activities. From a physiological perspective, the neutralization of free radicals is ensured by enzymatic, antioxidant and non-enzymatic defense systems. In the present chapter, we will focus on the endogenous enzymatic antioxidant defense system such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPxs), thioredoxin (Trx) and paraxonase which play an important role in homeostatic redox balance. Also, we will review this set of antioxidants enzymes within different pathological states such as diabetes, cancer, autoimmune diseases, cardiovascular, Alzheimer’s, Parkinson’s or parasitic diseases such as Leishmaniasis and Malaria.

2021 ◽  
Vol 22 (17) ◽  
pp. 9326
Author(s):  
Mirza Hasanuzzaman ◽  
Md. Rakib Hossain Raihan ◽  
Abdul Awal Chowdhury Masud ◽  
Khussboo Rahman ◽  
Farzana Nowroz ◽  
...  

The generation of oxygen radicals and their derivatives, known as reactive oxygen species, (ROS) is a part of the signaling process in higher plants at lower concentrations, but at higher concentrations, those ROS cause oxidative stress. Salinity-induced osmotic stress and ionic stress trigger the overproduction of ROS and, ultimately, result in oxidative damage to cell organelles and membrane components, and at severe levels, they cause cell and plant death. The antioxidant defense system protects the plant from salt-induced oxidative damage by detoxifying the ROS and also by maintaining the balance of ROS generation under salt stress. Different plant hormones and genes are also associated with the signaling and antioxidant defense system to protect plants when they are exposed to salt stress. Salt-induced ROS overgeneration is one of the major reasons for hampering the morpho-physiological and biochemical activities of plants which can be largely restored through enhancing the antioxidant defense system that detoxifies ROS. In this review, we discuss the salt-induced generation of ROS, oxidative stress and antioxidant defense of plants under salinity.


Animals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 462 ◽  
Author(s):  
Peter F. Surai ◽  
Ivan I. Kochish ◽  
Vladimir I. Fisinin ◽  
Darren T. Juniper

In commercial animals production, productive stress can negatively impact health status and subsequent productive and reproductive performance. A great body of evidence has demonstrated that as a consequence of productive stress, an overproduction of free radicals, disturbance of redox balance/signaling, and oxidative stress were observed. There is a range of antioxidants that can be supplied with animal feed to help build and maintain the antioxidant defense system of the body responsible for prevention of the damaging effects of free radicals and the toxic products of their metabolism. Among feed-derived antioxidants, selenium (Se) was shown to have a special place as an essential part of 25 selenoproteins identified in animals. There is a comprehensive body of research in monogastric species that clearly shows that Se bioavailability within the diet is very much dependent on the form of the element used. Organic Se, in the form of selenomethionine (SeMet), has been reported to be a much more effective Se source when compared with mineral forms such as sodium selenite or selenate. It has been proposed that one of the main advantages of organic Se in pig and poultry nutrition is the non-specific incorporation of SeMet into general body proteins, thus forming an endogenous Se reserve that can be utilized during periods of stress for additional synthesis of selenoproteins. Responses in ruminant species to supplementary Se tend to be much more variable than those reported in monogastric species, and much of this variability may be a consequence of the different fates of Se forms in the rumen following ingestion. It is likely that the reducing conditions found in the rumen are responsible for the markedly lower assimilation of inorganic forms of Se, thus predisposing selenite-fed animals to potential Se inadequacy that may in turn compromise animal health and production. A growing body of evidence demonstrates that organic Se has a number of benefits, particularly in dairy and beef animals; these include improved Se and antioxidant status and better Se transfer via the placenta, colostrum, and milk to the newborn. However, there is a paucity in the data concerning molecular mechanisms of SeMet assimilation, metabolism and selenoprotein synthesis regulation in ruminant animals, and as such, further investigation is required.


2019 ◽  
Vol 160 (36) ◽  
pp. 1407-1416
Author(s):  
Klára Szentmihályi

Abstract: The author briefly summarizes the relationship between oxidative stress and changes in metal ion metabolism in pathological processes. Essential metal ions such as Ca, Mg, Fe, Cu, Zn, Se are essential in the living organisms, their metabolism and intracellular concentration are strictly regulated. Externally or intrinsically, altered metal ion metabolism can lead to metal ion accumulation or metal ion deficiency. Excess amounts of redox-active essential metals such as Fe, Cu, Co, Cr, Ni can induce free radicals under certain circumstances that cause inflammation, cell damage, and cancerous changes, although the molecular mechanism is still unclear in every detail. Changes in the metabolism of non-essential and non-variable valence metal ions also affect redox homeostasis. Despite the fact that each metal can react in a unique way and with different mechanisms, similar processes occur, where both metal deficiency and excessive metal induce oxidative stress. Antioxidant defense system is damaged, free radicals produced alter the redox balance, and redox homeostasis changed induces the production of cytokines and other transcription factors that affect the intracellular signaling pathways and affect the development of various diseases, including metabolic, cardiovascular, neurological diseases and cancer. Orv Hetil. 2019; 160(36): 1407–1416.


MedPharmRes ◽  
2017 ◽  
Vol 2 (4) ◽  
pp. 1-6
Author(s):  
Binh Vong ◽  
Thuy Trinh ◽  
Nghiep Ngo ◽  
◽  
◽  
...  

Reactive oxygen species (ROS) or oxidative stress has been reported with strongly involving to pathogenesis of many diseases in human. On the other hand, ROS play a critical regulation as secondary signal to maintain intracellular redox equilibrium. Basically, the antioxidant defense systems in the body counteract with overproduced ROS. However, when the redox balance is broken under severe oxidative stress conditions, it leads to tissue injuries and numerous disorders. In this review, we briefly introduce the systems of ROS and antioxidants systems in the body and discuss the opposite roles of ROS in normal physiological conditions and diseases. For ROS-related diseases, conventional and currently developed antioxidant therapies are also described in this review.


2013 ◽  
Vol 304 (5) ◽  
pp. E495-E506 ◽  
Author(s):  
S. Keipert ◽  
M. Ost ◽  
A. Chadt ◽  
A. Voigt ◽  
V. Ayala ◽  
...  

Ectopic expression of uncoupling protein 1 (UCP1) in skeletal muscle (SM) mitochondria increases lifespan considerably in high-fat diet-fed UCP1 Tg mice compared with wild types (WT). To clarify the underlying mechanisms, we investigated substrate metabolism as well as oxidative stress damage and antioxidant defense in SM of low-fat- and high-fat-fed mice. Tg mice showed an increased protein expression of phosphorylated AMP-activated protein kinase, markers of lipid turnover (p-ACC, FAT/CD36), and an increased SM ex vivo fatty acid oxidation. Surprisingly, UCP1 Tg mice showed elevated lipid peroxidative protein modifications with no changes in glycoxidation or direct protein oxidation. This was paralleled by an induction of catalase and superoxide dismutase activity, an increased redox signaling (MAPK signaling pathway), and increased expression of stress-protective heat shock protein 25. We conclude that increased skeletal muscle mitochondrial uncoupling in vivo does not reduce the oxidative stress status in the muscle cell. Moreover, it increases lipid metabolism and reactive lipid-derived carbonyls. This stress induction in turn increases the endogenous antioxidant defense system and redox signaling. Altogether, our data argue for an adaptive role of reactive species as essential signaling molecules for health and longevity.


2009 ◽  
Vol 39 (4) ◽  
pp. 723-730 ◽  
Author(s):  
Jihong Qin ◽  
Qing Liu

In the subalpine zone of the Qinghai–Tibetan Plateau of China, Dragon spruce (Picea asperata Mast.) is commonly used for reforestation. The aim of the present work was to study the effects of seasonally frozen soil on the germination of P. asperata seeds and to investigate whether these effects were associated with resumption of the antioxidant defense system. The nonfrozen treatment resulted in near failure of germination (1%) and was associated with relatively high levels of hydrogen peroxide (H2O2) and low activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxide (APX). Germination of P. asperata seeds at 10 cm under the seasonally frozen soil was higher than that at 5 cm by 26%; this higher germination rate was associated with the recovery of SOD, CAT, and APX activities. The levels of malondialdehyde (MDA) in seeds from seasonally frozen treatments were higher than those in the nonfrozen treatment, implying greater lipid peroxidation and that frozen seeds might have suffered from oxidative stress. The results indicate that seasonally frozen soil facilitated the germination of P. asperata seeds and that germination was closely related to the resumption of antioxidant enzymes activity. Overall, these findings suggest that the disappearance of seasonally frozen ground caused by global warming might result in failure of regeneration of P. asperata.


2007 ◽  
Vol 23 (5-6-1) ◽  
pp. 181-191
Author(s):  
U. Kravchenko ◽  
G. Borjaev ◽  
M. Nevitov ◽  
A. Ostapchuk ◽  
E. Kistanova

The purpose of the present work was, under conditions of the model experiment on rats, to tap the information about the features of shortterm acclimatization of the antioxidant system in various organs to toxicity of cadmium at stages of an ontogenesis and about the preventive role of the antioxidant selenopyran in this process. The obtained results showed the ontogenetic differences in the adaptive reactivity of the enzymatic antioxidant defense system in the most important organs and tissues of rats under conditions of oxidative stress induced by cadmium. The ontogenetic differences of Se redistribution in a body under influence of cadmium administration were found. The discovered decrease of Se concentration in the liver of young animals and the increase of its concentration in the liver of old animals correlated positively with the changes of GPx activity. Preventive administration of selenopyran (9- phenyl-simmetrical octa-hydroselenoxanthene) to old animals reduced the oxidative stress intensity. Animals of all age groups showed higher selenium concentration in the tissues and the increase in the selenium-dependent GPx activity.


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