Reactive Oxygen Species-mediated Oxidative Stress Research Articles

Mechanical shear flow regulates the malignancy of colorectal cancer cells.

Colorectal cancer (CRC) is notable for its high mortality and high metastatic characteristics. The shear force generated by bloodstream provides mechanical signals regulating multiple responses of cells, including metastatic cancer cells, dispersing in blood vessels. We, therefore, studied the effect of shear flow on circulating CRC cells in the present study. The CRC cell line SW620 was subjected to shear flow of 12.5 dynes/cm2 for 1 and 2 h separately. Resulting elevated caspase-9 and -3 indicated that shear flow initiated the apoptosis of SW620. Enlarged cell size associated with a higher level of cyclin D1 was coincident with the flow cytometric results indicating that the cell cycle was arrested at the G1 phase. An elevated phosphor-eNOSS1177 increased the production of nitric oxide and led to reactive oxygen species-mediated oxidative stress. Shear flow also regulated epithelial-mesenchymal transition (EMT) by increasing E-cadherin and ZO-1 while decreasing Snail and Twist1. The migration and invasion of sheared SW620 were also substantially decreased. Further investigations showed that mitochondrial membrane potential was significantly decreased, whereas mitochondrial mass and ATP production were not changed. In addition to the shear flow of 12.5 dynes/cm2, the expressions of EMT were compared at lower (6.25 dynes/cm2) and at higher (25 dynes/cm2) shear flow. The results showed that lower shear flow increased mesenchymal characteristics and higher shear flow increased epithelial characteristics. Shear flow reduces the malignancy of CRC in their metastatic dispersal that opens up new ways to improve cancer therapies by applying a mechanical shear flow device.

Serratia marcescens induces apoptosis in Diaphorina citri gut cells via reactive oxygen species-mediated oxidative stress.

Asian citrus psyllid, Diaphorina citri, is a notorious pest in the citrus industry because it transmits Candidatus Liberibacter asiaticus, which causes an uncurable, devastating disease in citrus worldwide. Serratia marcescens is widely distributed in various environments that exhibits toxic effects to many insects. To develop strategies for enhancing the efficiency of pathogen-induced host mortality, a better understanding of the toxicity mechanism of Serratia marcescens on Diaphorina citri is critical. Serratia marcescens KH-001 successfully colonized Diaphorina citri gut by feeding artificial diets, resulting in the damage of cells including nucleus, mitochondria, vesicles, and microvilli. Oral ingestion of Serratia marcescens KH-001 strongly induced apoptosis in gut cells by enhancing levels of Cyt c, p53 and caspase-1 and decreasing levels of inhibitors of apoptosis (IAP) and Bax inhibitor-1 (BI-1). The expression of dual oxidase (Duox) and nitric oxide synthase (Nos) was up-regulated by Serratia marcescens KH-001, which increased hydrogen peroxide (H2 O2 ) levels in the gut. Injection of abdomen of Diaphorina citri with H2 O2 accelerated the death of the adults and induced apoptosis in the gut cells by activating Cyt c, p53 and caspase-1 and suppressing IAP and BI-1. Pretreatment of infected Diaphorina citri with vitamin c (Vc) increased the adult survival and diminished the apoptosis-inducing effect. The colonization of Serratia marcescens KH-001 in the guts of Diaphorina citri increased H2 O2 accumulation, leading to severe changes and apoptosis in intestinal cells, which enhanced a higher mortality level of D. citr. This study identifies the underlying virulence mechanism of Serratia marcescens KH-001 on Diaphorina citri that contributes to a widespread application in the integrated management of citrus psyllid. © 2023 Society of Chemical Industry.

Disulfiram Enhances the Antineoplastic Activity and Sensitivity of Murine Hepatocellular Carcinoma to 5-FU via Redox Management.

The efficacy of anticancer drug 5-FU is suppressed due to various factors, including severe side effects and decreased insensitivity during prolonged chemotherapy. Elevated endogenous copper (Cu) levels are one of the prominent hallmark features of cancer cells. In the present investigation, this feature was targeted in diethyl nitrosamine-phenobarbital-induced hepatocellular carcinoma (HCC) in a rat model system by an established anticancer drug, 5-FU, co-administered with copper and its chelating agent, disulfiram. After treatment with the test chemicals in HCC-induced rats, blood and liver samples were subjected to biochemical, molecular, and histopathological analyses. The analysis revealed that reactive oxygen species-mediated oxidative stress is the crucial etiological reason for the pathogenesis of HCC in rats, as evidenced by the significantly compromised activity of major antioxidant enzymes and elevated levels of oxidative damaged products with major histological alterations compared to the control. However, the combination of 5-FU with DSF demonstrated a significant improvement in most of the parameters, followed by 5-FU-Cu in the combination-treated groups. The combination treatment improved the histological details and triggered apoptosis in the cancer cells to a remarkable extent, as the levels of cleaved PARP and caspase-3 were significantly higher than those in the HCC rats treated with the drug alone. The present study envisages that manipulating the Cu-level greatly enhances the antineoplastic activity of 5-FU and sensitizes cancer cells to the increased efficacy of the drug.

N-acetylcysteine elevates Nrf-2/ARE-regulated antioxidant response and mitochondrial biogenesis in different brain regions of monocrotophos exposed rats

Monocrotophos (MCP) is reported to induce the reactive oxygen species-mediated oxidative stress, which is supposed to be one of main mechanisms of MCP-induced neurotoxicity. The present study depicts the positive role of N-acetylcysteine (NAC) against oxidative damage via nuclear factor-erythroid factor 2-related factor 2 (Nrf-2) pathway and mitochondrial biogenesis in different brain regions of rat. Male Albino Wistar rats were divided into control, NAC-treated, MCP and NAC+MCP-treated groups. An intragastric dose of MCP (0.9 mg/kg b.wt) and NAC (200 mg/kg b.wt) was administered for 28 days. Results showed that MCP significantly decreased the activities of mitochondrial complexes, altered the gene expression of Nrf-2/ARE-mediated phase-II detoxifying enzymes and mitochondrial biogenesis factors (peroxiredoxin 1, glutamate-cysteine ligase catalytic subunit, heme oxygenase, NAD(P)H: quinine oxidoreductase 1, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, mitochondrial transcription factor A, nuclear respiratory factors-1 and -2 and manganese superoxide dismutase). The co-administration of NAC modulated these altered mitochondrial biochemicals, restored the gene expressions of phase-II enzymes and mitochondrial biogenesis factors in different regions of rats’ brain. The finding of the present study suggest that NAC administration might protect against the MCP-induced neurotoxicity in rodents.

Zerumbone-induced reactive oxygen species-mediated oxidative stress re-sensitizes breast cancer cells to paclitaxel.

Chemotherapy is an effective approach for cancer therapy when plant-derived sensitizers are combined with chemotherapeutics. Zerumbone, a natural phytochemical, has been documented to have various pharmacological roles. Here, we evaluated the chemosensitization potential of zerumbone in a breast cancer cell line in vitro. Zerumbone-induced cytotoxicity in MCF-7 cells was assessed by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT)-based metabolic analysis. Reactive oxygen species (ROS)-mediated mitochondrial membrane alterations, DNA damage, and apoptotic morphological changes were measured by fluorescence microscopy methods. A biochemical assay was employed to analyze Thiobarbituric acid reactive substances (TBARS) and antioxidant levels. Apoptotic marker expression levels were investigated by immunoblotting. MTT assay revealed that zerumbone significantly enhanced paclitaxel (PTX)-induced cell death in breast cancer cells in a concentration-dependent manner. Furthermore, our study demonstrated that zerumbone (15 μM) significantly enhanced ROS when combined with PTX (1 μM) treatment. Additionally, we observed that zerumbone enhanced the impairment of mitochondrial membrane potential and oxidative DNA damage, thereby inducing apoptosis in combination with PTX. Western blot analysis indicated that zerumbone significantly upregulated BAX, caspase-7, and caspase-9 expression and decreased BCL-2 expression, thereby inducing proapoptotic protein-mediated cell death combined with PTX. The prooxidant properties of zerumbone potentially resensitize breast cancer cells to PTX by enhancing intracellular ROS-mediated oxidative stress.

Mechanisms of reactive oxygen species in oral lichen planus: A literature review

Oral lichen planus is a chronic non-infectious mucosal inflammatory disease caused by an imbalance between reactive oxygen species homeostasis and antioxidant defense systems. Notably, excessive oxidative stress products result in related autoimmune reactions. Further, it activates signaling pathways related to the development of oral lichen planus, as evidenced by the detection of damage to deoxyribonucleic acid, protein, and lipid. Thus, the mechanisms of reactive oxygen species-mediated oxidative stress in the pathogenesis of oral lichen planus are numerous and complex. In this review, we first introduce oxidative stress and oxidative products. Then, we summarize the role and possible mechanisms of reactive oxygen species-mediated oxidative stress in the pathogenesis of oral lichen planus and present a clinical correlation between oxidative stress and oral lichen planus. Finally, we discuss the current challenges and future perspectives.

PH-Responsive Oxygen and Hydrogen Peroxide Self-Supplying Nanosystem for Photodynamic and Chemodynamic Therapy of Wound Infection.

The combination of photodynamic therapy (PDT) and chemodynamic therapy (CDT) has been continuously explored in the antibacterial aspect and has achieved more effective antibacterial effect than a single therapy. We design a pH-responsive O2 and H2O2 self-supplying zeolitic imidazolate framework-67 (ZIF-67) nanosystem for PDT/CDT of wound infection. Under the acidic inflammatory conditions, ZIF-67 can degrade to produce Co2+ and release CaO2 and graphene quantum dots (GQDs). The exposed CaO2 reacted with water to generate H2O2 and O2. The self-supplied O2 alleviates hypoxia at the site of inflammation and enhances external light-initiated GQD-mediated PDT, while H2O2 was catalyzed by endogenous Co2+ to produce hydroxyl radicals for Co2+-triggered CDT. In vitro and in vivo experiments confirm that CaO2/GQDs@ZIF-67 has a combined PDT/CDT effect. The antibacterial mechanism indicates that bacteria post-treated with CaO2/GQDs@ZIF-67 may be sterilized by reactive oxygen species-mediated oxidative stress and the leakage of bacterial contents. The experiments also find that CaO2/GQDs@ZIF-67 may activate the immune response and enhance the therapeutic effect by activating the cyclic GMP-AMP synthase-stimulator of interferon genes signaling pathway.

Targeting mitochondrial reactive oxygen species-mediated oxidative stress attenuates nicotine-induced cardiac remodeling and dysfunction

Long-term nicotine intake is associated with an increased risk of myocardial damage and dysfunction. However, it remains unclear whether targeting mitochondrial reactive oxygen species (ROS) prevents nicotine-induced cardiac remodeling and dysfunction. This study investigated the effects of mitoTEMPO (a mitochondria-targeted antioxidant), and resveratrol (a sirtuin activator) , on nicotine-induced cardiac remodeling and dysfunction. Sprague–Dawley rats were administered 0.6 mg/kg nicotine daily with 0.7 mg/kg mitoTEMPO, 8 mg/kg resveratrol, or vehicle alone for 28 days. At the end of the study, rat hearts were collected to analyze the cardiac structure, mitochondrial ROS level, oxidative stress, and inflammation markers. A subset of rat hearts was perfused ex vivo to determine the cardiac function and myocardial susceptibility to ischemia–reperfusion injury. Nicotine administration significantly augmented mitochondrial ROS level, cardiomyocyte hypertrophy, fibrosis, and inflammation in rat hearts. Nicotine administration also induced left ventricular dysfunction, which was worsened by ischemia–reperfusion in isolated rat hearts. MitoTEMPO and resveratrol both significantly attenuated the adverse cardiac remodeling induced by nicotine, as well as the aggravation of postischemic ventricular dysfunction. Findings from this study show that targeting mitochondrial ROS with mitoTEMPO or resveratrol partially attenuates nicotine-induced cardiac remodeling and dysfunction.

Mechanisms of CuO Nanoparticles at an Environmentally Relevant Level Enhancing Production of Hydrogen from Anaerobic Fermentation of Waste-Activated Sludge

To date, almost all previous studies reported the inhibitory effects of CuO nanoparticles on the production of methane from waste-activated sludge (WAS), whereas their potential effects on hydrogen production remained unknown. This study investigated how CuO nanoparticles affected the production of hydrogen from WAS to fill this knowledge gap. Experimental results surprisingly showed CuO nanoparticles at an environmentally relevant level (5 mg/g of TS) significantly enhanced hydrogen production by 45.2 ± 0.1% compared to the control, while CuO nanoparticles at 50–100 mg/g of TS had little impact on hydrogen production. A mechanistic study revealed that although CuO nanoparticles at 5 mg/g of TS weakly inhibited acetogenesis, they enhanced WAS solubilization significantly, leading to improved hydrogen production. In contrast, although CuO nanoparticles at 50 and 100 mg/g of TS promoted WAS solubilization, the acidogenesis and acetogenesis processes were both suppressed, with the improvement offsetting inhibition. Microbial community analysis confirmed that CuO nanoparticles at high levels reduced the populations of key bacteria (e.g., Rhodobacter sp.) involved in hydrogen generation. Reactive oxygen species-mediated oxidative stress was revealed to be a key factor of CuO nanoparticle toxicity. This work revealed that anaerobic fermentation for hydrogen production rather than for methane production would be a better option for anaerobic treatment of sludge containing CuO nanoparticles.

Alda-1 Attenuates Hyperoxia-Induced Acute Lung Injury in Mice.

Acute lung injury (ALI), a milder form of acute respiratory distress syndrome (ARDS), is a leading cause of mortality in older adults with an increasing prevalence. Oxygen therapy, is a common treatment for ALI, involving exposure to a high concentration of oxygen. Unfortunately, hyperoxia induces the formation of reactive oxygen species which can cause an increase in 4-HNE (4-hydroxy 2 nonenal), a toxic byproduct of lipid peroxidation. Mitochondrial aldehyde dehydrogenase 2 (ALDH2) serves as an endogenous shield against oxidative stress-mediated damage by clearing 4-HNE. Alda-1 [(N-(1, 3 benzodioxol-5-ylmethyl)-2, 6- dichloro-benzamide)], a small molecular activator of ALDH2, protects against reactive oxygen species-mediated oxidative stress by promoting ALDH2 activity. As a result, Alda-1 shields against ischemic reperfusion injury, heart failure, stroke, and myocardial infarction. However, the mechanisms of Alda-1 in hyperoxia-induced ALI remains unclear. C57BL/6 mice implanted with Alzet pumps received Alda-1 in a sustained fashion while being exposed to hyperoxia for 48 h. The mice displayed suppressed immune cell infiltration, decreased protein leakage and alveolar permeability compared to controls. Mechanistic analysis shows that mice pretreated with Alda-1 also experience decreased oxidative stress and enhanced levels of p-Akt and mTOR pathway associated proteins. These results show that continuous delivery of Alda-1 protects against hyperoxia-induced lung injury in mice.

Study on the effect of reactive oxygen species-mediated oxidative stress on the activation of mitochondrial apoptosis and the tenderness of yak meat

This study investigated the effect of reactive oxygen species-mediated oxidative stress on activation of mitochondrial apoptosis and tenderness of yak meat during postmortem ageing. Oxidative stress degree, Ca2+ levels, membrane permeability transition pore opening, mitochondrial membrane potential, apoptotic factors and the shear force were examined. Results showed that the ROS generated by H2O2 significantly increased mitochondrial oxidative stress by decreasing the activities of superoxide dismutase, catalase and glutathione peroxidase, and increasing lipid peroxidation. Furthermore, oxidative stress enhanced Ca2+ production and cytochrome c release, changed the levels of Bcl-2 family proteins and activated caspase-9 and -3 activities. Ultimately, oxidative stress increased the apoptosis rate and tenderness of yak meat. These observations confirmed that ROS-mediated oxidative stress participates in the activation of the apoptotic cascade reaction involving Ca2+ and Bcl-2 family proteins. The results further suggested that ROS-mediated oxidative stress plays a significant role in meat tenderization through the mitochondrial apoptotic pathway.

Graphene Oxide-Coated Surface: Inhibition of Bacterial Biofilm Formation due to Specific Surface-Interface Interactions.

Graphene oxide (GO) is a promising and remarkable nanomaterial that exhibits antimicrobial activity due to its specific surface–interface interactions. In the present work, for the first time, we have reported the antibacterial activity of GO-coated surfaces prepared by two different methods (Hummers’ and improved, i.e., GOH and GOI) against bacterial biofilm formation. The bacterial toxicity of the deposited GO-coated surfaces was investigated for both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) models of bacteria. The mechanism of inhibition is different on the coated surface than that in suspension, as determined by measurement of the percentage inhibition of biofilm formation, Ellman’s assay, and colony forming unit (CFU) studies. The difference in the nature, degree of oxidative functionalities, and size of the synthesized GO nanoparticles mitigates biofilm formation. To better understand the antimicrobial mechanism of GO when coated on surfaces, we were able to demonstrate that beside reactive oxygen species-mediated oxidative stress, the physical properties of the GO-coated substrate effectively inactivate bacterial cell proliferation, which forms biofilms. Light and atomic force microscopy (AFM) images display a higher inhibition in the proliferation of planktonic cells in Gram-negative bacteria as compared to that in Gram-positive bacteria. The existence of a smooth surface with fewer porous domains in GOI inhibits biofilm formation, as demonstrated by optical microscopy and AFM images. The oxidative stress was found to be lower in the coated surface as compared to that in the suspensions as the latter enables exposure of both a large fraction of the active edges and functionalities of the GO sheets. In suspension, GOH is selective against S. aureus whereas GOI showed inhibition toward E. coli. This study provides new insights to better understand the bactericidal activity of GO-coated surfaces and contributes to the design of graphene-based antimicrobial surface coatings, which will be valuable in biomedical applications.

High glucose-induced p53 phosphorylation contributes to impairment of endothelial antioxidant system

High levels of glucose (HG) induce reactive oxygen species-mediated oxidative stress in endothelial cells (ECs), which leads to endothelial dysfunction and tissue damage. However, the molecular mechanisms involved in HG-induced endothelial oxidative stress and damage remain elusive. Here we show that cellular ATP level-modulated p53 Thr55 phosphorylation plays a critical role in the process. Upon HG exposure, the elevated ATP levels induced the kinase activity of TAF1 (TBP-associated factor 1), which leads to p53 Thr55 phosphorylation. The phosphorylation dissociates p53 from the glutathione peroxidase 1 (GPX1) promoter and results in reduction of GPX1 expression. Inhibition of TAF1-mediated p53 Thr55 phosphorylation abolished those events, supporting the role of TAF1 in sensing cellular ATP elevation and in regulating GPX1 expression under the HG condition. Importantly, treating cells with HG increased intracellular H2O2 and cell apoptosis, as well as suppressed nitric oxide (NO) bioavailability and tube network formation. These effects were also remarkably reversed by inhibition of TAF1 and p53 Thr55 phosphorylation. We conclude that HG leads to endothelial dysfunction via TAF1-mediated p53 Thr55 phosphorylation and subsequent GPX1 inactivation. Our study thus revealed a novel mechanism by which HG induces endothelial oxidative stress and damage and possibly provided an avenue for targeted therapy for diabetes-associated cardiovascular diseases.

Inorganic Arsenic Induces NRF2-Regulated Antioxidant Defenses in Both Cerebral Cortex and Hippocampus in Vivo.

Inorganic arsenic is reported to induce the reactive oxygen species-mediated oxidative stress, which is supposed to be one of the main mechanisms of arsenic-related neurological diseases. Nuclear factor erythroid 2-related factor 2 (NRF2), a master regulator of antioxidant defense systems, up-regulates the expression of target genes to fight against oxidative damages caused by harmful substances, including metals. In the present study, mice were used as a model to investigate the oxidative stress levels and the expressions of NRF2-regulated antioxidant substances in both cerebral cortex and hippocampus with 5, 10 and 20mg/kg NaAsO2 exposure intra-gastrically. Our results showed that acute NaAsO2 treatment resulted in decreased total anti-oxidative capacity (T-AOC) and increased maleic dialdehyde production in the nervous system. We also detected rapidly elevation of NRF2 protein levels by enhancement of Nrf2 transcription, especially at 20mg/kg NaAsO2 exposure group. In the meantime, mRNA and protein levels of Nrf2 encoding antioxidant enzymes heme oxygenase-1 (HO-1), NAD(P)H: quinine oxidoreductase 1 (NQO1) and glutathione S-transferase (GST) were consistently elevated time- and dose-dependently both in the cerebral cortex and hippocampus. Taken together, the presence study demonstrated the activation of NRF2 pathway, an early antioxidant defensive response, in both cerebral cortex and hippocampus upon inorganic arsenic (iAs) exposure in vivo. A better knowledge on the roles of NRF2 pathway in maintaining cellular redox homeostasis would be helpful for the strategies on improvement of neurotoxicity related to this metalloid.

ANTIDIABETIC, ANTIATHEROSCLEROTIC AND HEPATOPROTECTIVE PROPERTIES OF DECALEPIS HAMILTONII IN STREPTOZOTOCIN-INDUCED DIABETIC RATS

ABSTRACT Decalepis root is consumed as ingredient in pickles and is a common ingredient in many of the ayurvedic preparation. Streptozotocin (STZ) is a potential source of oxidative stress that induces diabetes. In the present study, we have investigated the effect of Decalepis root extract (DRE) on antioxidant defence system in the body and other diabetic complications in rats. Rats were prefed with DRE (0.05 and 0.1%) and then injected with STZ (50 mg/kg bodyweight, i.p.). The results demonstrated that STZ injection lead to increased oxidation of tissue lipids apart from diabetic changes, decreased activities of the antioxidant enzymes causing liver and DNA damage. In rats, which were prefed with DRE, peroxidation of lipids was prevented to a significant level (heart 19%, kidney 42% and liver 88%). DRE protected the rats against STZ induced oxidative stress, reduced the risk of oxidative stress, DNA damage and ameliorated liver damage and diabetic condition. PRACTICAL APPLICATIONS The results obtained in this study clearly demonstrated that Decalepis root extract is plant-derived and nontoxic, it could be introduced in the cancer therapy regime in combination with conventional therapeutic agents, after some more detailed investigation. This extract could be used not only as food preservative (to replace for the toxic butylated hydroxyanisole and butylated hydroxytoluene currently under use) but also can be used in the preparation of nutraceutical and pharmaceutical products. Reactive oxygen species-mediated oxidative stress is now regarded as a major factor leading to degenerative diseases such as ageing, cardiovascular disease, cancer, diabetes, stroke, osteoporosis, diseases of the brain and nervous system and eye diseases such as cataract and age-related macular degeneration; a suitable antioxidant therapies with the extract could be one of the medicine to control these degenerative diseases. This study presents cost effective source of highly potent antioxidants that is safe and natural with antidiabetic, anti-atherosclerotic and hepatoprotective properties.

Environmental Contamination of Chrysotile Asbestos and Its Toxic Effects on Antioxidative System of Lemna gibba

Asbestos was monitored in various plant samples around an asbestos cement factory. Asbestos residue was found on the surface of all plant samples monitored. Based on asbestos concentration found in different plant samples during monitoring and on the property of asbestos to cause reactive oxygen species-mediated oxidative stress in animal models, laboratory experiments were conducted to assess the toxicity of chrysotile asbestos on an aquatic macrophyte, duckweed (Lemna gibba.). L. gibba plants were exposed to four concentrations (0.5, 1.0, 2.0, and 5.0 microg/mL) of chrysotile asbestos under laboratory conditions, and alterations in the glutathione and ascorbate antioxidative system were estimated at postexposure days 7, 14, 21, and 28 in order to assess changes in their level as suitable biomarkers of chrysotile contamination. Chrysotile exposure caused a decrease in total and reduced glutathione and an enhancement in the oxidized glutathione as well as the reduced/oxidized glutathione ratio. An increase in ascorbate pool size, and reduced as well as oxidized ascorbate was found to be accompanied by a decrease in the ratio of reduced/oxidized ascorbate. Alteration in the glutathione and ascorbate level might be considered as a biomarker of exposure to an unsafe environment because these are essential compounds of the general antioxidative strategy to overcome oxidative stress due to environmental constraints. Because an increase in the oxidation rate of antioxidants weakens cellular defenses and indicates a precarious state, they could constitute indicators of toxicity.