Ebsulfur Is a Benzisothiazolone Cytocidal Inhibitor Targeting the Trypanothione Reductase of Trypanosoma brucei

Trypanosoma brucei is the causing agent of African trypanosomiasis. These parasites possess a unique thiol redox system required for DNA synthesis and defense against oxidative stress. It includes trypanothione and trypanothione reductase (TryR) instead of the thioredoxin and glutaredoxin systems of mammalian hosts. Here, we show that the benzisothiazolone compound ebsulfur (EbS), a sulfur analogue of ebselen, is a potent inhibitor of T. brucei growth with a favorable selectivity index over mammalian cells. EbS inhibited the TryR activity and decreased non-protein thiol levels in cultured parasites. The inhibition of TryR by EbS was irreversible and NADPH-dependent. EbS formed a complex with TryR and caused oxidation and inactivation of the enzyme. EbS was more toxic for T. brucei than for Trypanosoma cruzi, probably due to lower levels of TryR and trypanothione in T. brucei. Furthermore, inhibition of TryR produced high intracellular reactive oxygen species. Hydrogen peroxide, known to be constitutively high in T. brucei, enhanced the EbS inhibition of TryR. The elevation of reactive oxygen species production in parasites caused by EbS induced a programmed cell death. Soluble EbS analogues were synthesized and cured T. brucei brucei infection in mice when used together with nifurtimox. Altogether, EbS and EbS analogues disrupt the trypanothione system, hampering the defense against oxidative stress. Thus, EbS is a promising lead for development of drugs against African trypanosomiasis.

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From Past to Present: The Link Between Reactive Oxygen Species in Sperm and Male Infertility

Antioxidants ◽

10.3390/antiox8120616 ◽

2019 ◽

Vol 8 (12) ◽

pp. 616 ◽

Cited By ~ 3

Author(s):

Ana Izabel Silva Balbin Villaverde ◽

Jacob Netherton ◽

Mark A. Baker

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Male Infertility ◽

Mammalian Cells ◽

Reactive Oxygen ◽

Oxygen Species ◽

Signalling Molecules ◽

Function Impairment ◽

Enzymatic Mechanisms

Reactive oxygen species (ROS) can be generated in mammalian cells via both enzymatic and non-enzymatic mechanisms. In sperm cells, while ROS may function as signalling molecules for some physiological pathways, the oxidative stress arising from the ubiquitous production of these compounds has been implicated in the pathogenesis of male infertility. In vitro studies have undoubtedly shown that spermatozoa are indeed susceptible to free radicals. However, many reports correlating ROS with sperm function impairment are based on an oxidative stress scenario created in vitro, lacking a more concrete observation of the real capacity of sperm in the production of ROS. Furthermore, sample contamination by leukocytes and the drawbacks of many dyes and techniques used to measure ROS also greatly impact the reliability of most studies in this field. Therefore, in addition to a careful scrutiny of the data already available, many aspects of the relationship between ROS and sperm physiopathology are still in need of further controlled and solid experiments before any definitive conclusions are drawn.

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Clinical aspects of reactive oxygen and nitrogen species

Biochemical Society Symposium ◽

10.1042/bss0710121 ◽

2004 ◽

Vol 71 ◽

pp. 121-133 ◽

Cited By ~ 25

Author(s):

Ascan Warnholtz ◽

Maria Wendt ◽

Michael August ◽

Thomas Münzel

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Risk Factor ◽

Endothelial Dysfunction ◽

Vascular Tissue ◽

Rapid Development ◽

Reactive Oxygen ◽

Clinical Aspects ◽

No Production ◽

Oxygen Species

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.

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4-Hydroxychalcone Induces Cell Death via Oxidative Stress in MYCN-Amplified Human Neuroblastoma Cells

Oxidative Medicine and Cellular Longevity ◽

10.1155/2019/1670759 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 2

Author(s):

Amnah M. Alshangiti ◽

Eszter Tuboly ◽

Shane V. Hegarty ◽

Cathal M. McCarthy ◽

Aideen M. Sullivan ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Cell Death ◽

Cytotoxic Effect ◽

Neuroblastoma Cells ◽

Reactive Oxygen ◽

Prognostic Indicator ◽

Oxygen Species ◽

Human Neuroblastoma Cells ◽

Human Neuroblastoma

Neuroblastoma is an embryonal malignancy that arises from cells of sympathoadrenal lineage during the development of the nervous system. It is the most common pediatric extracranial solid tumor and is responsible for 15% of childhood deaths from cancer. Fifty percent of cases are diagnosed as high-risk metastatic disease with a low overall 5-year survival rate. More than half of patients experience disease recurrence that can be refractory to treatment. Amplification of the MYCN gene is an important prognostic indicator that is associated with rapid disease progression and a poor prognosis, highlighting the need for new therapeutic approaches. In recent years, there has been an increasing focus on identifying anticancer properties of naturally occurring chalcones, which are secondary metabolites with variable phenolic structures. Here, we report that 4-hydroxychalcone is a potent cytotoxin for MYCN-amplified IMR-32 and SK-N-BE (2) neuroblastoma cells, when compared to non-MYCN-amplified SH-SY5Y neuroblastoma cells and to the non-neuroblastoma human embryonic kidney cell line, HEK293t. Moreover, 4-hydroxychalcone treatment significantly decreased cellular levels of the antioxidant glutathione and increased cellular reactive oxygen species. In addition, 4-hydroxychalcone treatment led to impairments in mitochondrial respiratory function, compared to controls. In support of this, the cytotoxic effect of 4-hydroxychalcone was prevented by co-treatment with either the antioxidant N-acetyl-L-cysteine, a pharmacological inhibitor of oxidative stress-induced cell death (IM-54) or the mitochondrial reactive oxygen species scavenger, Mito-TEMPO. When combined with the anticancer drugs cisplatin or doxorubicin, 4-hydroxychalcone led to greater reductions in cell viability than was induced by either anti-cancer agent alone. In summary, this study identifies a cytotoxic effect of 4-hydroxychalcone in MYCN-amplified human neuroblastoma cells, which rationalizes its further study in the development of new therapies for pediatric neuroblastoma.

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Surface-bound reactive oxygen species generating nanozymes for selective antibacterial action

Nature Communications ◽

10.1038/s41467-021-20965-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Feng Gao ◽

Tianyi Shao ◽

Yunpeng Yu ◽

Yujie Xiong ◽

Lihua Yang

Keyword(s):

Reactive Oxygen Species ◽

Mammalian Cells ◽

Bacterial Resistance ◽

Reactive Oxygen ◽

Resistant Bacteria ◽

Oxygen Species ◽

Antibiotic Resistant ◽

Generate Surface ◽

Inert Substrate ◽

Silver Palladium

AbstractActing by producing reactive oxygen species (ROS) in situ, nanozymes are promising as antimicrobials. ROS’ intrinsic inability to distinguish bacteria from mammalian cells, however, deprives nanozymes of the selectivity necessary for an ideal antimicrobial. Here we report that nanozymes that generate surface-bound ROS selectively kill bacteria over mammalian cells. This result is robust across three distinct nanozymes that universally generate surface-bound ROS, with an oxidase-like silver-palladium bimetallic alloy nanocage, AgPd0.38, being the lead model. The selectivity is attributable to both the surface-bound nature of ROS these nanozymes generate and an unexpected antidote role of endocytosis. Though surface-bound, the ROS on AgPd0.38 efficiently eliminated antibiotic-resistant bacteria and effectively delayed the onset of bacterial resistance emergence. When used as coating additives, AgPd0.38 enabled an inert substrate to inhibit biofilm formation and suppress infection-related immune responses in mouse models. This work opens an avenue toward biocompatible nanozymes and may have implication in our fight against antimicrobial resistance.

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Protective Effects of Gintonin on Reactive Oxygen Species-Induced HT22 Cell Damages: Involvement of LPA1 Receptor-BDNF-AKT Signaling Pathway

Molecules ◽

10.3390/molecules26144138 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4138

Author(s):

Yeon-Jin Cho ◽

Sun-Hye Choi ◽

Ra-Mi Lee ◽

Han-Sung Cho ◽

Hyewhon Rhim ◽

...

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Signaling Pathway ◽

Reactive Oxygen ◽

Akt Signaling ◽

Atp Depletion ◽

Oxygen Species ◽

Akt Signaling Pathway ◽

Neuroprotective Effects ◽

Lpa1 Receptor

Gintonin is a kind of ginseng-derived glycolipoprotein that acts as an exogenous LPA receptor ligand. Gintonin has in vitro and in vivo neuroprotective effects; however, little is known about the cellular mechanisms underlying the neuroprotection. In the present study, we aimed to clarify how gintonin attenuates iodoacetic acid (IAA)-induced oxidative stress. The mouse hippocampal cell line HT22 was used. Gintonin treatment significantly attenuated IAA-induced reactive oxygen species (ROS) overproduction, ATP depletion, and cell death. However, treatment with Ki16425, an LPA1/3 receptor antagonist, suppressed the neuroprotective effects of gintonin. Gintonin elicited [Ca2⁺]i transients in HT22 cells. Gintonin-mediated [Ca2⁺]i transients through the LPA1 receptor-PLC-IP3 signaling pathway were coupled to increase both the expression and release of BDNF. The released BDNF activated the TrkB receptor. Induction of TrkB phosphorylation was further linked to Akt activation. Phosphorylated Akt reduced IAA-induced oxidative stress and increased cell survival. Our results indicate that gintonin attenuated IAA-induced oxidative stress in neuronal cells by activating the LPA1 receptor-BDNF-TrkB-Akt signaling pathway. One of the gintonin-mediated neuroprotective effects may be achieved via anti-oxidative stress in nervous systems.

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How to express the antioxidant properties of substances properly?

Chemical Papers ◽

10.1007/s11696-021-01799-1 ◽

2021 ◽

Author(s):

Małgorzata Olszowy-Tomczyk

Keyword(s):

Oxidative Stress ◽

Reactive Oxygen Species ◽

Literature Review ◽

Antioxidant Activities ◽

Antioxidant Properties ◽

Reactive Oxygen ◽

The Body ◽

Universal Method ◽

Oxygen Species ◽

Good Tool

AbstractOxidative stress, associated with an imbalance between the oxidants (reactive oxygen species) and the antioxidants in the body, contributes to the development of many diseases. The body’s fight against reactive oxygen species is supported by antioxidants. Nowadays, there are too many analytical methods, but there is no one universal technique for assessing antioxidant properties. Moreover, the applied different ways of expressing the results lead to their incompatibility and unreasonable interpretation. The paper is a literature review concerning the most frequent ways of antioxidant activities expression and for an easy and universal method of the obtained results discussion. This paper is an attempt to point out their disadvantages and advantages. The manuscript can support the searching interpretation of the obtained results which will be a good tool for the development of a number of fields, especially medicine what can help in the future detection and treatment of many serious diseases. Graphic abstract

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The role of oxidative/nitrosative stress in pathogenesis of paracetamol-induced toxic hepatitis

Medicinski pregled ◽

10.2298/mpns1012827r ◽

2010 ◽

Vol 63 (11-12) ◽

pp. 827-832 ◽

Cited By ~ 7

Author(s):

Tatjana Radosavljevic ◽

Dusan Mladenovic ◽

Danijela Vucevic ◽

Rada Jesic-Vukicevic

Keyword(s):

Oxidative Stress ◽

Nitric Oxide ◽

Reactive Oxygen Species ◽

Liver Injury ◽

Kupffer Cells ◽

Reactive Oxygen ◽

Oxygen Species ◽

Severe Liver ◽

Hepatocellular Necrosis

Introduction. Paracetamol is an effective analgesic/antipyretic drug when used at therapeutic doses. However, the overdose of paracetamol can cause severe liver injury and liver necrosis. The mechanism of paracetamol-induced liver injury is still not completely understood. Reactive metabolite formation, depletion of glutathione and alkylation of proteins are the triggers of inhibition of mitochondrial respiration, adenosine triphosphate depletion and mitochondrial oxidant stress leading to hepatocellular necrosis. Role of oxidative stress in paracetamol-induced liver injury. The importance of oxidative stress in paracetamol hepatotoxicity is controversial. Paracetamol induced liver injury cause the formation of reactive oxygen species. The potent sources of reactive oxygen are mitochondria, neutrophils, Kupffer cells and the enzyme xatnine oxidase. Free radicals lead to lipid peroxidation, enzymatic inactivation and protein oxidation. Role of mitochondria in paracetamol-induced oxidative stress. The production of mitochondrial reactive oxygen species is increased, and the glutathione content is decreased in paracetamol overdose. Oxidative stress in mitochondria leads to mito?chondrial dysfunction with adenosine triphosphate depletion, increase mitochondrial permeability transition, deoxyribonu?cleic acid fragmentation which contribute to the development of hepatocellular necrosis in the liver after paracetamol overdose. Role of Kupffer cells in paracetamol-induced liver injury. Paracetamol activates Kupffer cells, which then release numerous cytokines and signalling molecules, including nitric oxide and superoxide. Kupffer cells are important in peroxynitrite formation. On the other hand, the activated Kupffer cells release anti-inflammatory cytokines. Role of neutrophils in paracetamol-induced liver injury. Paracetamol-induced liver injury leads to the accumulation of neutrophils, which release lysosomal enzymes and generate superoxide anion radicals through the enzyme nicotinamide adenine dinucleotide phosphate oxidase. Hydrogen peroxide, which is influenced by the neutrophil-derived enzyme myeloperoxidase, generates hypochlorus acid as a potent oxidant. Role of peroxynitrite in paracetamol-induced oxidative stress. Superoxide can react with nitric oxide to form peroxynitrite, as a potent oxidant. Nitrotyrosine is formed by the reaction of tyrosine with peroxynitrite in paracetamol hepatotoxicity. Conclusion. Overdose of paracetamol may produce severe liver injury with hepatocellular necrosis. The most important mechanisms of cell injury are metabolic activation of paracetamol, glutathione depletion, alkylation of proteins, especially mitochondrial proteins, and formation of reactive oxygen/nitrogen species.

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