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1.
Hydrogen peroxide-induced stress acclimation in plants.
Qureshi, MK, GawroĊski, P, Munir, S, Jindal, S, Kerchev, P
Cellular and molecular life sciences : CMLS. 2022;(2):129
Abstract
Among all reactive oxygen species (ROS), hydrogen peroxide (H2O2) takes a central role in regulating plant development and responses to the environment. The diverse role of H2O2 is achieved through its compartmentalized synthesis, temporal control exerted by the antioxidant machinery, and ability to oxidize specific residues of target proteins. Here, we examine the role of H2O2 in stress acclimation beyond the well-studied transcriptional reprogramming, modulation of plant hormonal networks and long-distance signalling waves by highlighting its global impact on the transcriptional regulation and translational machinery.
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2.
Therapeutic potential of flavonoids in cancer: ROS-mediated mechanisms.
Slika, H, Mansour, H, Wehbe, N, Nasser, SA, Iratni, R, Nasrallah, G, Shaito, A, Ghaddar, T, Kobeissy, F, Eid, AH
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2022;:112442
Abstract
Cancer is a leading cause of morbidity and mortality around the globe. Reactive oxygen species (ROS) play contradicting roles in cancer incidence and progression. Antioxidants have attracted attention as emerging therapeutic agents. Among these are flavonoids, which are natural polyphenols with established anticancer and antioxidant capacities. Increasing evidence shows that flavonoids can inhibit carcinogenesis via suppressing ROS levels. Surprisingly, flavonoids can also trigger excessive oxidative stress, but this can also induce death of malignant cells. In this review, we explore the inherent characteristics that contribute to the antioxidant capacity of flavonoids, and we dissect the scenarios in which they play the contrasting role as pro-oxidants. Furthermore, we elaborate on the pathways that link flavonoid-mediated modulation of ROS to the prevention and treatment of cancer. Special attention is given to the ROS-mediated anticancer functions that (-)-epigallocatechin gallate (EGCG), hesperetin, naringenin, quercetin, luteolin, and apigenin evoke in various cancers. We also delve into the structure-function relations that make flavonoids potent antioxidants. This review provides a detailed perspective that can be utilized in future experiments or trials that aim at utilizing flavonoids or verifying their efficacy for developing new pharmacologic agents. We support the argument that flavonoids are attractive candidates for cancer therapy.
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3.
Improving oxidative stress resilience in plants.
Kerchev, PI, Van Breusegem, F
The Plant journal : for cell and molecular biology. 2022;(2):359-372
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Abstract
Originally conceived as harmful metabolic byproducts, reactive oxygen species (ROS) are now recognized as an integral part of numerous cellular programs. Thanks to their diverse physicochemical properties, compartmentalized production, and tight control exerted by the antioxidant machinery they activate signaling pathways that govern plant growth, development, and defense. Excessive ROS levels are often driven by adverse changes in environmental conditions, ultimately causing oxidative stress. The associated negative impact on cellular constituents have been a major focus of decade-long research efforts to improve the oxidative stress resilience by boosting the antioxidant machinery in model and crop species. We highlight the role of enzymatic and non-enzymatic antioxidants as integral factors of multiple signaling cascades beyond their mere function to prevent oxidative damage under adverse abiotic stress conditions.
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4.
Effects of Salinity Stress on Chloroplast Structure and Function.
Hameed, A, Ahmed, MZ, Hussain, T, Aziz, I, Ahmad, N, Gul, B, Nielsen, BL
Cells. 2021;(8)
Abstract
Salinity is a growing problem affecting soils and agriculture in many parts of the world. The presence of salt in plant cells disrupts many basic metabolic processes, contributing to severe negative effects on plant development and growth. This review focuses on the effects of salinity on chloroplasts, including the structures and function of these organelles. Chloroplasts house various important biochemical reactions, including photosynthesis, most of which are considered essential for plant survival. Salinity can affect these reactions in a number of ways, for example, by changing the chloroplast size, number, lamellar organization, lipid and starch accumulation, and interfering with cross-membrane transportation. Research has shown that maintenance of the normal chloroplast physiology is necessary for the survival of the entire plant. Many plant species have evolved different mechanisms to withstand the harmful effects of salt-induced toxicity on their chloroplasts and its machinery. The differences depend on the plant species and growth stage and can be quite different between salt-sensitive (glycophyte) and salt-tolerant (halophyte) plants. Salt stress tolerance is a complex trait, and many aspects of salt tolerance in plants are not entirely clear yet. In this review, we discuss the different mechanisms of salt stress tolerance in plants with a special focus on chloroplast structure and its functions, including the underlying differences between glycophytes and halophytes.
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5.
A novel multi-target strategy to attenuate the progression of Parkinson's disease by diamine hybrid AGE/ALE inhibitor.
Sasaki, NA, Sonnet, P
Future medicinal chemistry. 2021;(24):2185-2200
Abstract
Instead of a conventional 'one-drug-one-target approach', this article presents a novel multi-target approach with a concept of trapping simultaneously as many detrimental factors as possible involved in the progression of Parkinson's disease. These factors include reactive carbonyl species, reactive oxygen species, Fe3+/Cu2+ and ortho-quinones (o-quinone), in particular. Different from the known multi-target strategies for Parkinson's disease, it is a sort of 'vacuum cleaning' strategy. The new agent consists of reactive carbonyl species scavenging moiety and reactive oxygen species scavenging and metal chelating moiety linked by a spacer. Provided that the capacity of scavenging o-quinones is demonstrated, this type of agent can further broaden its potential therapeutic profile. In order to support this new hypothetical approach, a number of simple in vitro experiments are proposed.
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6.
Use of Thiols in the Treatment of COVID-19: Current Evidence.
Cazzola, M, Rogliani, P, Salvi, SS, Ora, J, Matera, MG
Lung. 2021;(4):335-343
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Abstract
There is a possible role for oxidative stress, a state characterized by an altered balance between the production of free radicals or reactive oxygen species (ROS) and antioxidant defences, in coronavirus disease 2019 (COVID-19), the genesis of which is quite complex. Excessive oxidative stress could be responsible for the alveolar damage, thrombosis, and red blood cell dysregulation observed in COVID-19. Apparently, deficiency of glutathione (GSH), a low-molecular-weight thiol that is the most important non-enzymatic antioxidant molecule and has the potential to keep the cytokine storm in check, is a plausible explanation for the severe manifestations and death in COVID-19 patients. Thiol drugs, which are considered mucolytic, also possess potent antioxidant and anti-inflammatory properties. They exhibit antibacterial activity against a variety of medically important bacteria and may be an effective strategy against influenza virus infection. The importance of oxidative stress during COVID-19 and the various pharmacological characteristics of thiol-based drugs suggest a possible role of thiols in the treatment of COVID-19. Oral and intravenous GSH, as well as GSH precursors such as N-acetylcysteine (NAC), or drugs containing the thiol moiety (erdosteine) may represent a novel therapeutic approach to block NF-kB and address the cytokine storm syndrome and respiratory distress observed in COVID-19 pneumonia patients.
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7.
Reactive Oxygen Species as a Link between Antioxidant Pathways and Autophagy.
Li, D, Ding, Z, Du, K, Ye, X, Cheng, S
Oxidative medicine and cellular longevity. 2021;:5583215
Abstract
Reactive oxygen species (ROS) are highly reactive molecules that can oxidize proteins, lipids, and DNA. Under physiological conditions, ROS are mainly generated in the mitochondria during aerobic metabolism. Under pathological conditions, excessive ROS disrupt cellular homeostasis. High levels of ROS result in severe oxidative damage to the cellular machinery. However, a low/mild level of ROS could serve as a signal to trigger cell survival mechanisms. To prevent and cope with oxidative damage to biomolecules, cells have developed various antioxidant and detoxifying mechanisms. Meanwhile, ROS can initiate autophagy, a process of self-clearance, which helps to reduce oxidative damage by engulfing and degrading oxidized substance. This review summarizes the interactions among ROS, autophagy, and antioxidant pathways. The effects of natural phytochemicals on autophagy induction, antioxidation, and dual-function are also discussed.
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Melatonin interferes with COVID-19 at several distinct ROS-related steps.
Camp, OG, Bai, D, Gonullu, DC, Nayak, N, Abu-Soud, HM
Journal of inorganic biochemistry. 2021;:111546
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Abstract
Recent studies have shown a correlation between COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and the distinct, exaggerated immune response titled "cytokine storm". This immune response leads to excessive production and accumulation of reactive oxygen species (ROS) that cause clinical signs characteristic of COVID-19 such as decreased oxygen saturation, alteration of hemoglobin properties, decreased nitric oxide (NO) bioavailability, vasoconstriction, elevated cytokines, cardiac and/or renal injury, enhanced D-dimer, leukocytosis, and an increased neutrophil to lymphocyte ratio. Particularly, neutrophil myeloperoxidase (MPO) is thought to be especially abundant and, as a result, contributes substantially to oxidative stress and the pathophysiology of COVID-19. Conversely, melatonin, a potent MPO inhibitor, has been noted for its anti-inflammatory, anti-oxidative, anti-apoptotic, and neuroprotective actions. Melatonin has been proposed as a safe therapeutic agent for COVID-19 recently, having been given with a US Food and Drug Administration emergency authorized cocktail, REGEN-COV2, for management of COVID-19 progression. This review distinctly highlights both how the destructive interactions of HOCl with tetrapyrrole rings may contribute to oxygen deficiency and hypoxia, vitamin B12 deficiency, NO deficiency, increased oxidative stress, and sleep disturbance, as well as how melatonin acts to prevent these events, thereby improving COVID-19 prognosis.
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9.
Oxidative stress in the skin: Impact and related protection.
Chen, J, Liu, Y, Zhao, Z, Qiu, J
International journal of cosmetic science. 2021;(5):495-509
Abstract
Skin, our first interface to the external environment, is subjected to oxidative stress caused by a variety of factors such as solar ultraviolet, infrared and visible light, environmental pollution, including ozone and particulate matters, and psychological stress. Excessive reactive species, including reactive oxygen species and reactive nitrogen species, exacerbate skin pigmentation and aging, which further lead to skin tone unevenness, pigmentary disorder, skin roughness and wrinkles. Besides these, skin microbiota are also a very important factor ensuring the proper functions of skin. While environmental factors such as UV and pollutants impact skin microbiota compositions, skin dysbiosis results in various skin conditions. In this review, we summarize the generation of oxidative stress from exogenous and endogenous sources. We further introduce current knowledge on the possible roles of oxidative stress in skin pigmentation and aging, specifically with emphasis on oxidative stress and skin pigmentation. Meanwhile, we summarize the science and rationale of using three well-known antioxidants, namely vitamin C, resveratrol and ferulic acid, in the treatment of hyperpigmentation. Finally, we discuss the strategy for preventing oxidative stress-induced skin pigmentation and aging.
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Deterioration of orthodox seeds during ageing: Influencing factors, physiological alterations and the role of reactive oxygen species.
Zhang, K, Zhang, Y, Sun, J, Meng, J, Tao, J
Plant physiology and biochemistry : PPB. 2021;:475-485
Abstract
Seed viability is an important trait in agriculture which directly influences seedling emergence and crop yield. However, even when stored under optimal conditions, all seeds will eventually lose their viability. Our primary aims were to describe factors influencing seed deterioration, determine the morphological, physiological, and biochemical changes that occur during the process of seed ageing, and explore the mechanisms involved in seed deterioration. High relative humidity and high temperature are two factors that accelerate seed deterioration. As seeds age, frequently observed changes include membrane damage and the destruction of organelle structure, an increase in the loss of seed leachate, decreases of respiratory rates and ATP production, and a loss of enzymatic activity. These phenomena could be inter-related and reflect the general breakdown in cellular organization. Many processes can result in seed ageing; it is likely that oxidative damage caused by free radicals and reactive oxygen species (ROS) is primarily responsible. ROS can have vital interactions with any macromolecule of biological interest that result in damage to various cellular components caused by protein damage, lipid peroxidation, chromosomal abnormalities, and DNA lesions. Further, ROS may also cause programmed cell death by inducing the opening of mitochondrial permeability transition pores and the release of cytochrome C. Some repairs can occur in the early stages of imbibition, but repair processes fail if sufficient damage has been caused to critical functional components. As a result, a given seed will lose its viability and eventually fail to germinate in a relatively short time period.