scholarly journals An online monitor of the oxidative capacity of aerosols (o-MOCA)

2017 ◽  
Vol 10 (2) ◽  
pp. 633-644 ◽  
Author(s):  
Arantzazu Eiguren-Fernandez ◽  
Nathan Kreisberg ◽  
Susanne Hering
Keyword(s):  
Oxidative Stress ◽  
Limit Of Detection ◽  
Ambient Air ◽  
Oxidative Capacity ◽  
Cellular Damage ◽  
In Vitro Assays ◽  
Time Resolved ◽  
Consumption Rates ◽  
Online Monitor

Abstract. The capacity of airborne particulate matter to generate reactive oxygen species (ROS) has been correlated with the generation of oxidative stress both in vitro and in vivo. The cellular damage from oxidative stress, and by implication with ROS, is associated with several common diseases, such as asthma and chronic obstructive pulmonary disease (COPD), and some neurological diseases. Yet currently available chemical and in vitro assays to determine the oxidative capacity of ambient particles require large samples, analyses are typically done offline, and the results are not immediate.Here we report the development of an online monitor of the oxidative capacity of aerosols (o-MOCA) to provide online, time-resolved assessment of the capacity of airborne particles to generate ROS. Our approach combines the Liquid Spot Sampler (LSS), which collects particles directly into small volumes of liquid, and a chemical module optimized for online measurement of the oxidative capacity of aerosol using the dithiothreitol (DTT) assay. The LSS uses a three-stage, laminar-flow water condensation approach to enable the collection of particles as small as 5 nm into liquid. The DTT assay has been improved to allow the online, time-resolved analysis of samples collected with the LSS but could be adapted to other collection methods or offline analysis of liquid extracts.The o-MOCA was optimized and its performance evaluated using the 9,10-phenanthraquinone (PQ) as a standard redox-active compound. Laboratory testing shows minimum interferences or carryover between consecutive samples, low blanks, and a reproducible, linear response between the DTT consumption rate (nmol min−1) and PQ concentration (µM). The calculated limit of detection for o-MOCA was 0.15 nmol min−1. The system was validated with a diesel exhaust particle (DEP) extract, previously characterized and used for the development, improvement, and validation of the standard DTT analysis. The DTT consumption rates (nmol min−1) obtained with the o-MOCA were within experimental uncertainties of those previously reported for these DEP samples. In ambient air testing, the fully automated o-MOCA was run unattended for 3 days with 3 h time resolution and showed a diurnal and daily variability in the measured consumption rates (nmol min−1 m−3).

scholarly journals An On-line Monitor of the Oxidative Capacity of Aerosols (o-MOCA)

2016 ◽  
Author(s):  
Arantzazu Eiguren-Fernandez ◽  
Nathan Kreisberg ◽  
Susanne Hering
Keyword(s):  
Oxidative Stress ◽  
Limit Of Detection ◽  
Ambient Air ◽  
Oxidative Capacity ◽  
Cellular Damage ◽  
In Vitro Assays ◽  
Time Resolved ◽  
Consumption Rates ◽  
On Line

Abstract. The capacity of airborne particulate matter to generate reactive oxygen species (ROS) has been correlated with the generation of oxidative stress both in-vitro and in-vivo. The cellular damage from oxidative stress, and by implication with ROS, is associated with several common diseases such as asthma, chronic obstructive pulmonary disease (COPD), and some neurological diseases. Yet currently available chemical and in-vitro assays to determine the oxidative capacity of ambient particles require large samples, analysis are typically done offline, and the results are not immediate. In this manuscript we report the development of an on-line monitor of the oxidative capacity of aerosols (o-MOCA) to provide on-line, time-resolved assessment of the capacity of airborne particles to generate ROS. Our approach combines the Liquid Spot Sampler (LSS), which collects particles directly into small volumes of liquid, and a chemical module optimized for on-line measurement of the oxidative capacity of aerosol using the dithiothreitol (DTT) assay. The LSS uses a three-stage, laminar-flow water condensation approach to enable the collection of particles as small as 5 nm into liquid, without subjecting the sample to temperature extremes. The DTT assay has been improved to allow the on-line, time-resolved analysis of samples collected with the LSS. The o-MOCA was optimized and its performance evaluated using the 9,10-Phenanthraquinone (PQ) as standard redox-active compound. Laboratory testing shows minimum interferences or carry-over between consecutive samples, low blanks, and a reproducible, linear response between the DTT consumption rate (nmol/min) and PQ concentration (µM). The calculated limit of detection for o-MOCA was 0.15 nmol/min. The system was validated with a Diesel Exhaust Particle (DEP) extract, previously characterized and used for the development, improvement, and validation of the standard DTT analysis. The DTT consumption rates (nmol/min) obtained with the o-MOCA were within experimental uncertainties of those previously reported for these DEP samples. In ambient air testing, the fully automated o-MOCA was run unattended for 3 days with 3-h time resolution, and showed a diurnal and daily variability in the measured consumption rates (nmol/min/m3).

scholarly journals Influence of Oxidative Stress on Time-Resolved Oxygen Detection by [Ru(Phen)3]2+ In Vivo and In Vitro

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 485
Author(s):  
Veronika Huntosova ◽  
Denis Horvath ◽  
Robert Seliga ◽  
Georges Wagnieres
Keyword(s):  
Oxidative Stress ◽  
Tissue Oxygenation ◽  
Intact Cell ◽  
Molecular Probes ◽  
Stress Factors ◽  
Time Resolved ◽  
Invasive Approach ◽  
Oxygen Detection

Detection of tissue and cell oxygenation is of high importance in fundamental biological and in many medical applications, particularly for monitoring dysfunction in the early stages of cancer. Measurements of the luminescence lifetimes of molecular probes offer a very promising and non-invasive approach to estimate tissue and cell oxygenation in vivo and in vitro. We optimized the evaluation of oxygen detection in vivo by [Ru(Phen)3]2+ in the chicken embryo chorioallantoic membrane model. Its luminescence lifetimes measured in the CAM were analyzed through hierarchical clustering. The detection of the tissue oxygenation at the oxidative stress conditions is still challenging. We applied simultaneous time-resolved recording of the mitochondrial probe MitoTrackerTM OrangeCMTMRos fluorescence and [Ru(Phen)3]2+ phosphorescence imaging in the intact cell without affecting the sensitivities of these molecular probes. [Ru(Phen)3]2+ was demonstrated to be suitable for in vitro detection of oxygen under various stress factors that mimic oxidative stress: other molecular sensors, H2O2, and curcumin-mediated photodynamic therapy in glioma cancer cells. Low phototoxicities of the molecular probes were finally observed. Our study offers a high potential for the application and generalization of tissue oxygenation as an innovative approach based on the similarities between interdependent biological influences. It is particularly suitable for therapeutic approaches targeting metabolic alterations as well as oxygen, glucose, or lipid deprivation.

scholarly journals A Comparative Study of the Antioxidative Effects of Helichrysum italicum and Helichrysum arenarium Infusions

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 380
Author(s):  
Katja Kramberger ◽  
Zala Jenko Pražnikar ◽  
Alenka Baruca Arbeiter ◽  
Ana Petelin ◽  
Dunja Bandelj ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
High Performance ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Morphological Type ◽  
Mass Spectrometry Analysis ◽  
In Vitro Assays ◽  
Spectrometry Analysis ◽  
Stress Related Genes

Helichrysum arenarium (L.) Moench (abbrev. as HA) has a long tradition in European ethnomedicine and its inflorescences are approved as a herbal medicinal product. In the Mediterranean part of Europe, Helichrysum italicum (Roth) G. Don (abbrev. as HI) is more common. Since infusions from both plants are traditionally used, we aimed to compare their antioxidative potential using in vitro assays. Two morphologically distinct HI plants, HIa and HIb, were compared to a commercially available HA product. Genetic analysis using microsatellites confirmed a clear differentiation between HI and HA and suggested that HIb was a hybrid resulting from spontaneous hybridization from unknown HI subspecies. High-performance liquid chromatography–mass spectrometry analysis showed the highest amounts of hydroxycinnamic acids and total arzanol derivatives in HIa, whereas HIb was richest in monohydroxybenzoic acids, caffeic acids, and coumarins, and HA contained the highest amounts of flavonoids, especially flavanones. HIa exhibited the highest radical scavenging activity; it was more efficient in protecting different cell lines from induced oxidative stress and in inducing oxidative stress-related genes superoxide dismutase 1, catalase, and glutathione reductase 1. The antioxidative potential of HI was not only dependent on the morphological type of the plant but also on the harvest date, revealing important information for obtaining the best possible product. Considering the superior properties of HI compared to HA, the evaluation of HI as a medicinal plant could be recommended.

scholarly journals Intra-Vitreal Administration of Microvesicles Derived from Human Adipose-Derived Multipotent Stromal Cells Improves Retinal Functionality in Dogs with Retinal Degeneration

2019 ◽  
Vol 8 (4) ◽  
pp. 510
Author(s):  
Anna Cislo-Pakuluk ◽  
Agnieszka Smieszek ◽  
Natalia Kucharczyk ◽  
Peter G.C. Bedford ◽  
Krzysztof Marycz
Keyword(s):  
Oxidative Stress ◽  
Retinal Degeneration ◽  
Stromal Cells ◽  
Clinical Studies ◽  
Stress Conditions ◽  
In Vitro Assays ◽  
Multipotent Stromal Cells ◽  
Mitochondrial Potential ◽  
And Oxidative Stress

This study was designed to determine the influence of microvesicles (MVs) derived from multipotent stromal cells isolated from human adipose tissue (hASCs) on retinal functionality in dogs with various types of retinal degeneration. The biological properties of hASC-MVs were first determined using an in vitro model of retinal Muller-like cells (CaMLCs). The in vitro assays included analysis of hASC-MVs influence on cell viability and metabolism. Brain-derived neurotrophic factor (BDNF) expression was also determined. Evaluation of the hASC-MVs was performed under normal and oxidative stress conditions. Preliminary clinical studies were performed on ten dogs with retinal degeneration. The clinical studies included behavioral tests, fundoscopy and electroretinography before and after hASC-MVs intra-vitreal injection. The in vitro study showed that CaMLCs treated with hASC-MVs were characterized by improved viability and mitochondrial potential, both under normal and oxidative stress conditions. Additionally, hASC-MVs under oxidative stress conditions reduced the number of senescence-associated markers, correlating with the increased expression of BDNF. The preliminary clinical study showed that the intra-vitreal administration of hASC-MVs significantly improved the dogs’ general behavior and tracking ability. Furthermore, fundoscopy demonstrated that the retinal blood vessels appeared to be less attenuated, and electroretinography using HMsERG demonstrated an increase in a- and b-wave amplitude after treatment. These results shed promising light on the application of cell-free therapies in veterinary medicine for retinal degenerative disorders treatment.

scholarly journals The Zebrafish Embryo as a Model to Test Protective Effects of Food Antioxidant Compounds

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5786
Author(s):  
Cristina Arteaga ◽  
Nuria Boix ◽  
Elisabet Teixido ◽  
Fernanda Marizande ◽  
Santiago Cadena ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Zebrafish Embryo ◽  
In Vitro Assays ◽  
Antioxidant Compounds ◽  
Protective Effects ◽  
Tert Butyl Hydroperoxide ◽  
In Vivo Effects ◽  
Β Carotene

The antioxidant activity of food compounds is one of the properties generating the most interest, due to its health benefits and correlation with the prevention of chronic disease. This activity is usually measured using in vitro assays, which cannot predict in vivo effects or mechanisms of action. The objective of this study was to evaluate the in vivo protective effects of six phenolic compounds (naringenin, apigenin, rutin, oleuropein, chlorogenic acid, and curcumin) and three carotenoids (lycopene B, β-carotene, and astaxanthin) naturally present in foods using a zebrafish embryo model. The zebrafish embryo was pretreated with each of the nine antioxidant compounds and then exposed to tert-butyl hydroperoxide (tBOOH), a known inducer of oxidative stress in zebrafish. Significant differences were determined by comparing the concentration-response of the tBOOH induced lethality and dysmorphogenesis against the pretreated embryos with the antioxidant compounds. A protective effect of each compound, except β-carotene, against oxidative-stress-induced lethality was found. Furthermore, apigenin, rutin, and curcumin also showed protective effects against dysmorphogenesis. On the other hand, β-carotene exhibited increased lethality and dysmorphogenesis compared to the tBOOH treatment alone.

scholarly journals Inhibition of Digestive Enzymes, Antioxidant and Free Radical Scavenging Capacities of Stem Bark Extracts of Coula edulis Baill (Olacaceae)

2021 ◽  
Vol 10 (5) ◽  
pp. 1
Author(s):  
Eric Beyegue ◽  
Boris G. K. Azantsa ◽  
Angie M-A Mbong ◽  
Julius E. Oben
Keyword(s):  
Oxidative Stress ◽  
Free Radical ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Ethanolic Extract ◽  
Stem Bark ◽  
Alpha Amylase ◽  
In Vitro Assays ◽  
Oh Radicals

Prolonged hyperglycemia enhances oxidative stress. Bioactive compounds extracted possess antioxidant, anti-free radical potentials or the ability to reduce blood sugar levels. The objective of this study was to evaluate the antioxidant properties of extracts of stem bark of Coula edulis Baill., their abilities to trap free radicals and glucose, as well as their ability to inhibit α-amylase and invertase activities. In vitro assays were used to test the trapping capacity of extracts on DPPH, ABTS, NO, and OH radicals; to evaluate the antioxidant capacity, the activity of glycosylation and the capacity of inhibition of the activities of α-amylase and invertase were conducted. Also, phenolic, flavonoid and alkaloid contents of extracts were determined. Results showed that extracts of the stem bark of C. edulis have anti-radical properties. The extracts chelate DPPH, hydroxyl (OH), nitrite oxide (NO), ABTS radicals, and even glucose. The IC50 values varied depending on the nature of the extraction solvent. Ethanolic extract has the highest polyphenolic content (289.12 ± 30.31 µg catechin equivalent/g), flavonoids (1.12 ± 0.09 µg quercetin equivalent/g) and alkaloids (5.54 ± 0.59 µg quinin equivalent/g). The extracts also reduce invertase and α-amylase activities. C. edulis extracts present strong antioxidant potentials and can be used as a source of natural antioxidants for the prevention of oxidative stress and hyperglycemia.

Immunomodulatory Drugs Inhibit H2O2 Decomposition in Multiple Myeloma Cells and Its Mediated Cytotoxicity Is Determined By Cellular Antioxidative Capacity

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2475-2475
Author(s):  
Sinto Sebastian Chirackal ◽  
Yuan Xiao Zhu ◽  
Esteban Braggio ◽  
Chang-Xin Shi ◽  
Sonali Panchabhai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Multiple Myeloma ◽  
Protein Expression ◽  
Cell Lines ◽  
Oxidative Capacity ◽  
Antioxidative Capacity ◽  
H2o2 Decomposition ◽  
Gene And Protein Expression ◽  
Induced Apoptosis

Abstract Introduction Lenalidomide is an immunomodulatory drug (IMID) used to treat Multiple Myeloma (MM). Although a role for cereblon (CRBN)-mediated degradation of Ikaros proteins (IKZF1 and IKZF3) has been shown, the complete molecular and biochemical mechanisms responsible for lenalidomide-mediated anti-MM activity and/or resistance are undiscovered. Therefore, we aimed to analyze whether IMIDs (thalidomide, lenalidomide, and pomalidomide) are inducing oxidative stress in MM and what determines these drugs varying sensitivity and/or resistance. Methodology Amplex Red Assay has been performed to analyze IMIDs-mediated inhibition of H2O2 decomposition in both, in-vitro and in-vivo assays. Lentiviruses were prepared in 293T cells for CRBN, IgL-λ & IgL-k, and Bim knockdown experiment. Quantification of MM cellular anti-oxidative capacity for determining IMID sensitivity was standardized with H2O2-mediated oxidation of FADH2 and NAD(P)H. To measure apoptosis and gene expression analysis 106 cells were incubated with lenalidomide for 24 to 96 hours before they were examined by annexin-PI and FACS analysis. Gene and protein expression were measured by RT-PCR, western blot, and immunohistochemistry. Results We discovered that IMIDs inhibit peroxidase-mediated decomposition of H2O2 in both, in vitro horseradish peroxidase (HRP) assays and in human MM cell lines (HMCLs). Of the IMIDs analyzed, pomalidomide was the more potent inhibitor. H2O2 treatment effectively degraded IKZF1 and IKZF3 in HMCLs. To confirm the central role of CRBN in IKZF1 and IKZF3 degradation by H2O2-induced oxidative stress, we used CRBN knockdown OPM2 isogeneic cells and the CRBN-overexpressing OCIMY-5 cell line. We treated both sets of isogenic cell lines with lenalidomide and H2O2 for 3 hours, and we showed that H2O2 similarly mediates IKZF1 and IKZF3 degradation in a CRBN-dependent fashion. Next, we tested viability of CRBN present and absent cell lines with increasing concentrations of lenalidomide and H2O2 for 3 days. Lenalidomide-induced cytotoxicity was CRBN dependent, but H2O2 was not after 3 days, as shown by MTT assays. The capacity of MM cells to decompose H2O2 was measured via a biochemical test that quantitatively measured cellular anti-oxidative capacity. IMID sensitivity was well correlated with cellular anti-oxidative capacity, likely, cells more efficiently decompose H2O2was resistant and cells were not sensitive to IMID. This result shows that antioxidant capacity determines lenalidomide sensitivity among HMCLs with similar CRBN protein expression. We discovered that lenalidomide-mediated cytotoxicity in MM was attributable to oxidative damage of intracellular immunoglobulin proteins. By using several sets of isogenic cells lines with and without CRBN expression, we confirmed that lenalidomide treatment caused accumulation of IgL dimers only in CRBN-positive cells. Lenalidomide-induced IgL dimerization lead to decreased secretion and consequent intracellular accumulation of IgL, as evidenced by unchanged IgL mRNA expression, increased total intracellular IgL protein, and decreased secretion of IgL. After 72 hours of lenalidomide treatment we found decreased XBP-1u, increased XBP-1s, and over-expressed GRP78/BiP endoplasmic reticulum stress (ERS) marker proteins in CRBN positive cells but not in CRBN knock-down cells. We observed Bim requirement, especially BimEL, after lenalidomide treatment in CRBN-positive lenalidomide-sensitive cells. Our data reveals that lenalidomide-mediated; progressive ERS can positively enhance bortezomib-induced apoptosis in an in-vitro MM model. We pretreated MM cells with lenalidomide and then treated them with bortezomib. OPM2 cells pretreated with lenalidomide for 2 days clearly showed increased sensitivity to bortezomib-induced apoptosis compared with cells that were not pretreated. Conclusion IMIDs inhibit H2O2 decomposition. Ikaros protein degradation is a consequence of H2O2 mediated oxidative stress. Therefore, cells producing high H2O2 and with less antioxidative capacity are more sensitive to IMIDs. On the basis of this discovery, we would be able to predict which patients will benefit from IMIDs-mediated therapy and develop new drugs other than IMIDs that can inhibit intracellular H2O2 decomposition in MM. At present, CRBN may be required for IMIDs to effectively inhibit H2O2decomposition. Disclosures Chirackal: Mayo Clinic: Patents & Royalties: Filed a professional US patent for quantifying cellular anti-oxidative capacity. Fonseca:Mayo Clinic: Patents & Royalties: Filed a professional US patent for quantifying cellular anti-oxidative capacity.

scholarly journals Protective Mechanisms of Flavonoids in Parkinson’s Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Kasthuri Bai Magalingam ◽  
Ammu Kutty Radhakrishnan ◽  
Nagaraja Haleagrahara
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Movement Disorder ◽  
Dopaminergic Neurons ◽  
Target Therapy ◽  
Cellular Damage ◽  
Substantia Nigra Pars Compacta ◽  
Protective Mechanisms

Parkinson’s disease is a chronic, debilitating neurodegenerative movement disorder characterized by progressive degeneration of dopaminergic neurons in thesubstantia nigra pars compactaregion in human midbrain. To date, oxidative stress is the well accepted concept in the etiology and progression of Parkinson’s disease. Hence, the therapeutic agent is targeted against suppressing and alleviating the oxidative stress-induced cellular damage. Within the past decades, an explosion of research discoveries has reported on the protective mechanisms of flavonoids, which are plant-based polyphenols, in the treatment of neurodegenerative disease using bothin vitroandin vivomodels. In this paper, we have reviewed the literature on the neuroprotective mechanisms of flavonoids in protecting the dopaminergic neurons hence reducing the symptoms of this movement disorder. The mechanism reviewed includes effect of flavonoids in activation of endogenous antioxidant enzymes, suppressing the lipid peroxidation, inhibition of inflammatory mediators, flavonoids as a mitochondrial target therapy, and modulation of gene expression in neuronal cells.

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