Understanding oxidants and antioxidants: Classical team with new players

Abstract

The free radical oxidants such as reactive oxygen species, reactive nitrogen species, and reactive sulfur species are produced inside cells through various metabolic processes. The body is equipped with an antioxidant defense system that guards against oxidative damage caused by these reactive oxidants and plays a major role in protecting cells from oxidative stress and damage. Antioxidants such as glutathione (GSH), thioredoxin, ascorbic acid and enzymes, for example, superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) counter the oxidative stress and protect lipids, proteins, and DNA. Antioxidants such as tocopherols, ascorbic acid, carotenoids, flavonoids, amino acids are also natural antioxidants present in foods. There is increasing demand and availability of designer foods fortified with antioxidants and probiotics that may be important in human health. The review article presents a brief overview of oxidants and antioxidant systems inside the human body including the role of probiotics and inflammation. Practical applications Antioxidants such as GSH, thioredoxin, ascorbic acid, etc. and protective enzymes, for example, SOD, GPx, CAT, etc. counter oxidative stress and protect cellular biomolecules. Antioxidants such as tocopherols, ascorbic acid, carotenoids, flavonoids, amino acids, phospholipids, and sterols are natural antioxidants found in consumed foods. They play a major role in scavenging free radical and non‐radical oxidants, and protect cells from oxidative stress and damage. The importance of antioxidants can be understood from the fact that oxidative damage is now associated with a variety of diseases including cancer, neurodegeneration, diabetes, etc. Several approaches to improve human health and achieve longevity use dietary antioxidants as formulation in diet and fortified foods. Antioxidants also maintain freshness and prolonging the shelf life of food products. The fortified or designer foods that are added with antioxidant nutrients and the use of microorganisms as probiotics are increasingly available in the market as health foods and supplements.

Neurotoxic Anatoxin-a Can Also Exert Immunotoxicity by the Induction of Apoptosis on Carassius auratus Lymphocytes in vitro When Exposed to Environmentally Relevant Concentrations

“…CAT and SOD, which decompose hydrogen peroxide and superoxide anions, are important in the first defense line of organisms against excess free radicals (Yang et al, 2014). SOD activity correlates well with the immune competence of aquatic organisms because SOD is significant in minimizing the oxidative damage to host cells in immune defenses (Ali et al, 2020). Poniedzialek et al (2015) suggested that the exposure of cylindrospermopsin (CYN) induces a dose-dependent increase in H 2 O 2 concentration in 0.5 h, and when the concentration of H 2 O 2 was highest, the activities of SOD and CAT decreased significantly.…”

“…Throughout the entire antioxidant protection process, GR can catalyze GSSG to form GSH, and GPX catalysis can help GSH to remove H 2 O 2 from cells. GSH, an important nonenzyme antioxidant substance in cells, can prevent oxidative damage caused by reactive oxidants, can directly or indirectly maintain intracellular oxidative balance, and plays a significant role in protecting cells from oxidative stress (Ali et al, 2020). Rymuszka and Sieroslawska (2018) revealed that in primary leukocytes and small-cell lung cancer cells exposed to nodularin (0.01-0.1 mu g/mL), intracellular ROS production increased significantly and GSH levels decreased.…”

Investigation of Heterologously Expressed Glucose-6-Phosphate Dehydrogenase Genes in a Yeast zwf1 Deletion

“…All cells from bacteria to humans have developed mechanisms to cope with oxidative stress caused by reactive oxygen species (ROS), which are a by-product of respiratory metabolism and cause damage to membranes and DNA [1]. The importance of corresponding signaling pathways that elicit a proper cellular response to ROS accumulation, especially in tumor cells, has been underlined by studies ultimately earning last year's award of the Nobel prize for physiology and medicine (see [2], and references therein).…”

A comparative study on normal and obese mice indicates that the secretome of mesenchymal stromal cells is influenced by tissue environment and physiopathological conditions

“…Catalase protects cells from the toxic effects of hydrogen peroxide, and GSR maintains high levels of reduced glutathione in the cell cytoplasm [23]. BLVRA, CRAT, Nampt, and Sorcin are part of metabolic networks.…”