scholarly journals Bimodal Behavior of Ascorbic Acid in Musca domestica Larvae

2021 ◽  
Vol 12 (4) ◽  
pp. 5199-5216
Keyword(s):  
Oxidative Stress ◽  
Ascorbic Acid ◽  
Musca Domestica ◽  
Food Supplement ◽  
Water Soluble ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Dietary Antioxidant ◽  
High Concentrations ◽  
Normal Food

Ascorbic acid (Vitamin C) is an excellent water-soluble dietary antioxidant, well known to protect the biomolecules from oxidative stress-linked damages. It is reported to show a contrary behavior by inflicting pro-oxidant effects under varied, altered circumstances. The present work is an attempt to study the antioxidant and pro-oxidant behavior of ascorbic acid in Musca domestica larvae. Its pro-oxidant properties were tested by exposing the larvae to various concentrations of ascorbic acid. For confirming its oxidant scavenging properties, its effects on the antioxidant enzyme profiles were studied in both the normal and stress-induced M. domestica larvae. Oxidative stress was induced by adding D-Galactose (D-Gal) to the normal food supplement of the larvae. Outcomes of the study demonstrate that ascorbic acid acts as an efficient antioxidant when added in lower concentrations, but at high concentrations, it induces oxidative stress in the larvae, thus acting as a pro-oxidant. At the concentration of 10 mM, ascorbic acid significantly reduced the oxidative stress induced by D-Gal (p < 0.05) and maintained the percent pupal survival and percent eclosion. In conclusion, we suggest that ascorbic acid may function as an antioxidant and pro-oxidant in a concentration-dependent manner under normal physiological conditions.

scholarly journals A kinetic study of the effects of galactocerebroside 3-sulphate on human spleen glucocerebrosidase. Evidence for two activator-binding sites

1986 ◽  
Vol 237 (3) ◽  
pp. 655-662 ◽  
Author(s):  
E M Prence ◽  
K O Garrett ◽  
R H Glew
Keyword(s):  
Binding Sites ◽  
Kinetic Studies ◽  
Sodium Cholate ◽  
Water Soluble ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Human Spleen ◽  
High Concentrations ◽  
High Control

Extraction of control human spleen glucocerebrosidase with sodium cholate and butan-l-ol reversibly inactivates the enzyme in terms of its ability to hydrolyse the water-soluble substrate 4-methylumbelliferyl beta-D-glucopyranoside (MUGlc). The acidic brain lipid galactocerebroside 3-sulphate (sulphatide) reconstitutes beta-glucosidase activity in a strongly concentration-dependent manner. In this study we show that sulphatide exhibits three critical micellar concentrations (CMCs): CMC1, 3.72 microM; CMC2, 22.6 microM; CMC3, 60.7 microM. We designate the aggregates formed at these CMCs as primary, secondary and tertiary micelles respectively. From the results of kinetic studies performed at various sulphatide concentrations (0.012-248 microM), we found that sulphatide monomers (less than 3 microM) decreased the Km (for MUGlc) of control glucocerebrosidase from 11 to 4.6 mM, and lowered the Vmax. 2-fold. However, secondary and tertiary micelles were required for expression of high control glucocerebrosidase activities. Glucocerebrosidase prepared from the spleen of a patient with non-neuronopathic type 1 Gaucher's disease exhibited a very low Km (2.8 mM) even in the absence of exogenous lipid, and sulphatide monomers had no effect on the mutant enzyme's Km or Vmax. However, secondary or tertiary micelles markedly increased the Vmax. of the type 1 glucocerebrosidase to 60% of the corresponding control enzyme value. In contrast, for the glucocerebrosidase of the neuronopathic type 2 case, although sulphatide decreased the Km from 9.2 to 1.7 mM, the Vmax. never reached more than 5% that of the control enzyme, even at high concentrations of sulphatide. In addition, we found that secondary and tertiary sulphatide micelles enhanced the rate of inactivation of all three glucocerebrosidase preparations by chymotrypsin. Collectively, these results indicate the presence of two sulphatide-binding sites on glucocerebrosidase: one that enhances substrate binding, and another that enhances catalysis.

Neutrophil Elastase Potentiates Cathepsin G-lnduced Platelet Activation

1992 ◽  
Vol 68 (05) ◽  
pp. 570-576 ◽  
Author(s):  
Mary A Selak
Keyword(s):  
Neutrophil Elastase ◽  
Cell Activation ◽  
Thromboxane A2 ◽  
Creatine Phosphate ◽  
Dense Granule ◽  
Cathepsin G ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Low Concentrations ◽  
High Concentrations

SummaryWe have previously demonstrated that human neutrophil cathepsin G is a strong platelet agonist that binds to a specific receptor. This work describes the effect of neutrophil elastase on cathepsin G-induced platelet responses. While platelets were not activated by high concentrations of neutrophil elastase by itself, elastase enhanced aggregation, secretion and calcium mobilization induced by low concentrations of cathepsin G. Platelet aggregation and secretion were potentiated in a concentration-dependent manner by neutrophil elastase with maximal responses observable at 200 nM. Enhancement was observed when elastase was preincubated with platelets for time intervals of 10–60 s prior to addition of a low concentration of cathepsin G and required catalytically-active elastase since phenylmethanesulphonyl fluoride-inhibited enzyme failed to potentiate cell activation. Neutrophil elastase potentiation of platelet responses induced by low concentrations of cathepsin G was markedly inhibited by creatine phosphate/creatine phosphokinase and/or indomethacin, indicating that the synergism between elastase and cathepsin G required the participation of ADP and thromboxane A2. On the other hand, platelet responses were not attenuated by the PAF antagonist BN 52021, signifying that PAF-acether did not play a role in elastase potentiation. At higher concentrations porcine pancreatic elastase exhibits similar effects to neutrophil elastase, demonstrating that the effect of elastase was not unique to the neutrophil protease. While neutrophil elastase failed to alter the ability of cathepsin G to hydrolyze a synthetic chromogenic substrate, preincubation of platelets with elastase increased the apparent affinity of cathepsin G binding to platelets. In contrast to their effect on cathepsin G-induced platelet responses, neither neutrophil nor pancreatic elasatse potentiated aggregation or dense granule release initiated by ADP, PAF-acether, arachidonic acid or U46619, a thromboxane A2 mimetic. Moreover, unlike its effect on cathepsin G, neutrophil elastase inhibited thrombin-induced responses. The current observations demonstrate that elastase can potentiate platelet responses mediated by low concentrations of cathepsin G, suggesting that both enzymes may function synergistically to activate platelets under conditions where neutrophil degranulation occurs.

Inducible nitric oxide synthase augments injury elicited by oxidative stress in rat cardiac myocytes

1998 ◽  
Vol 274 (1) ◽  
pp. C245-C252 ◽  
Author(s):  
Junsuke Igarashi ◽  
Masashi Nishida ◽  
Shiro Hoshida ◽  
Nobushige Yamashita ◽  
Hiroaki Kosaka ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Cardiac Myocytes ◽  
Myocardial Injury ◽  
No Production ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
No Donor ◽  
Oxide Synthase ◽  
Gpx Activity

The effects of nitric oxide (NO) produced by cardiac inducible NO synthase (iNOS) on myocardial injury after oxidative stress were examined. Interleukin-1β induced cultured rat neonatal cardiac myocytes to express iNOS. After induction of iNOS,l-arginine enhanced NO production in a concentration-dependent manner. Glutathione peroxidase (GPX) activity in myocytes was attenuated by elevated iNOS activity and by an NO donor, S-nitroso- N-acetyl-penicillamine (SNAP). Although NO production by iNOS did not induce myocardial injury, NO augmented release of lactate dehydrogenase from myocyte cultures after addition of H2O2(0.1 mM, 1 h). Inhibition of iNOS with Nω-nitro-l-arginine methyl ester ameliorated the effects of NO-enhancing treatments on myocardial injury and GPX activity. SNAP augmented the myocardial injury induced by H2O2. Inhibition of GPX activity with antisense oligodeoxyribonucleotide for GPX mRNA increased myocardial injury by H2O2. Results suggest that the induction of cardiac iNOS promotes myocardial injury due to oxidative stress via inactivation of the intrinsic antioxidant enzyme, GPX.

scholarly journals Concentration-Dependent Antioxidant/Pro-Oxidant Activity of Ascorbic Acid in Chickens

2012 ◽  
Vol 66 (6) ◽  
pp. 256-260
Author(s):  
Nadežda Berzina ◽  
Jurijs Markovs ◽  
Mirdza Apsīte ◽  
Svetlana Vasiļjeva ◽  
Galina Smirnova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ascorbic Acid ◽  
Cadmium Concentration ◽  
Dehydroascorbic Acid ◽  
Cadmium Accumulation ◽  
Suppressive Effect ◽  
High Dose ◽  
Dependent Manner ◽  
Treatment Groups ◽  
Liver And Kidney

The effects of ascorbic acid supplementation on biomarkers of oxidative stress, cadmium accumulation in organs, immune system activity and kidney function in chickens were investigated. The treatment groups of chickens were fed either plain diet or diet supplemented with ascorbic acid at 100, 500, 1000 and 2000 mg/kg for four weeks. Liver and kidney tissues were assayed for cadmium concentration, and the hepatic levels of ascorbic acid and dehydroascorbic acid (DHAA; the oxidised form), malondialdehyde, glutathione, activity of glutathione peroxidase, blood serum uric acid, creatinine, lysozyme and circulating immune complexes were measured. Supplementation with a high dose of ascorbic acid (1000 and 2000 mg/kg in the diet) caused an imbalance between pro-oxidative and antioxidative activities, and induced a suppressive effect on innate immunity. The results suggest that oxidative stress compromises renal function. We observed that ascorbic acid increased cadmium accumulation in a dose-dependent manner.

scholarly journals Preclinical Study on the Ameliorating Effect of L-Ascorbic Acid for the Oxidative Stress of Caused by Chronic Administration of Organic Nitrates in Cardiovascular Diseases

2021 ◽  
Author(s):  
Ahmed M Hamdan ◽  
Zuhair M. Mohammedsaleh ◽  
Aalaa Aboelnour ◽  
Sherif M.H. Elkhannishi
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Ascorbic Acid ◽  
Chronic Administration ◽  
Stress Factors ◽  
Male Rats ◽  
Oxidative Stress Marker ◽  
Organic Nitrates ◽  
Dependent Manner ◽  
Dose Dependent

Abstract PurposeThe therapeutic activity of Glyceryl trinitrate (GTN) is mainly regulated by liberating nitric oxide (NO) and reactive nitrogen species (RNS). During this biotransformation, oxidative stress and lipid peroxidation inside the red blood cells (RBCs) occur. The principal objective of our research is to explain the ameliorating effect of L-ascorbic acid for the deleterious effects of chronic administration of nitrovasodilator drugs. MethodsWe studied some biochemical parameters for the oxidative stress using groups of high sucrose/fat (HSF) diet Wistar male rats chronically orally administered ISMN. Afterwards, we evaluated the role of L-ascorbic acid against these biochemical changes. ResultsChronic treatment with organic nitrates caused elevated serum levels of lipid peroxidation, hemoglobin derivatives as methemoglobin and carboxyhemoglobin, rate of hemoglobin autoxidation, the cellular levels of pro-inflammatory cytokines marker (NF-κB) and apoptosis markers (caspase-3) in myocardium muscles in a dose dependent manner. Meanwhile, such exposure caused decline in the enzymatic effect of superoxide dismutase (SOD), glutathione (GSH) and catalase activity (CAT) accompanied with a decrease of in the level of mitochondrial oxidative stress marker (nrf2) in myocardium muscles and decrease in the serum iron and total iron binding capacity (TIBC) in a dose dependent manner. Concomitant treatment with L-ascorbic acid significantly diminished these changes for all examined parameters.ConclusionChronic administration of organic nitrates leads to the alteration of the level of oxidative stress factors in the myocardium tissue due to generation of reactive oxygen species. Using vitamin C can effectively ameliorate such intoxication to overcome the nitrate tolerance.

scholarly journals In Vitro Antioxidant Activity of Dibenz[b,f]azepine and its Analogues

2008 ◽  
Vol 5 (s2) ◽  
pp. 1123-1132 ◽  
Author(s):  
H. Vijay Kumar ◽  
C. R. Gnanendra ◽  
Nagaraja Naik ◽  
D. Channe Gowda
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
In Vitro Models ◽  
Antioxidant Compounds ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Dibenz[b,f]azepine and its five derivatives bearing different functional groups were synthesized by known methods. The compounds thus synthesized were evaluated for antioxidant potential through different in vitro models such as (DPPH) free radical scavenging activity,ß-carotene-linoleic acid model system, reducing power assay and phosphomolybdenum method. Under our experimental condition among the synthesized compounds dibenz[b,f]azepine (a) and 10-methoxy-5H-dibenz[b,f]azepine (d) exhibited potent antioxidant activity in concentration dependent manner in all the above four methods. Butylated hydroxyl anisole (BHA) and ascorbic acid (AA) were used as the reference antioxidant compounds. The most active compounds like dibenz[b,f]azepine and its methoxy group substituent have shown more promising antioxidant and radical scavengers compared to the standards like BHA and ascorbic acid. It is conceivable from the studies that the tricyclic amines,i.e. dibenz[b, f]azepine and some of its derivatives are effective in their antioxidant activity properties.

Effects of Mg2+ on Ca2+ waves and Ca2+ transients of rat ventricular myocytes

1996 ◽  
Vol 270 (3) ◽  
pp. H907-H914 ◽  
Author(s):  
H. Terada ◽  
H. Hayashi ◽  
N. Noda ◽  
H. Satoh ◽  
H. Katoh ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Channel Blocker ◽  
Ventricular Myocytes ◽  
Inhibitory Effect ◽  
Antiarrhythmic Action ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Triggered Activity ◽  
Rat Ventricular Myocytes ◽  
High Concentrations

It has been shown that the occurrence of the transient inward current, which is responsible for triggered activity, was often associated with propagating regions of increased intracellular Ca2+ concentration ([Ca2+]i), i.e., the “Ca2+ wave.” To investigate the mechanism of antiarrhythmic action of Mg2+, we have studied effects of high concentrations of Mg2+ on Ca2+ waves in isolated rat ventricular myocytes. [Ca2+]i was estimated using the Ca(2+)-indicating probe indo 1. Ca2+ waves in myocytes, stimulated at 0.2 Hz, were induced by perfusion of isoproterenol (10(-7) M). High Mg2+ concentration suppressed Ca2+ waves in a concentration-dependent manner (36% at 4 mM, 70% at 8 mM, and 82% at 12 mM). The Ca2+ channel blocker verapamil also suppressed Ca2+ waves in a similar way. In contrast with marked depression of Ca2+ transients by verapamil, Ca2+ transients were not affected by high Mg2+ concentration (8 mM). High Mg2+ concentration also reduced frequencies of Ca2+ waves in the absence of electrical stimulation, whereas verapamil failed to reduce frequencies of Ca2+ waves. Reduction in frequency of Ca2+ waves by high Mg2+ concentration was associated with slowing of propagation velocity of Ca2+ waves. To examine whether suppressive effects of high Mg2+ concentration on Ca2+ waves were related to an increase in intracellular Mg2+ concentration ([Mg2+]i), the effect of high-Mg2+ solution on [Mg2+]i was examined in myocytes loaded with mag-fura 2. An increase in extracellular Mg2+ concentration from 1 to 12 mM increased [Mg2+]i from 1.06 +/- 0.16 to 1.87 +/- 0.22 mM (P < 0.01) in 30 min. To examine the effect of high Mg2+ concentration on amount of releasable Ca2+ in the sarcoplasmic reticulum, the effect of high Mg2+ concentration on the Ca2+ transient induced by a rapid application of caffeine was examined. High-Mg2+ solution increased the peak of the caffeine-induced Ca2+ transient. These results suggest that the inhibitory effect of Mg2+ on Ca2+ waves was not due to inhibition of the sarcolemmal Ca2+ channel but could be due to a decreased propensity for the sarcoplasmic reticulum to divest itself of excess Ca2+.

scholarly journals Antioxidant and Wound Healing Property of Gelsolin in 3T3-L1 Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Bhavna Vaid ◽  
Bhupinder Singh Chopra ◽  
Sachin Raut ◽  
Amin Sagar ◽  
Maulik D. Badmalia ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Wound Healing ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Plasma Gelsolin ◽  
Total Antioxidant ◽  
Effective Role ◽  
Healing Property ◽  
Injury Recovery

Delineation of factors which affect wound healing would be of immense value to enable on-time or early healing and reduce comorbidities associated with infections or biochemical stress like diabetes. Plasma gelsolin has been identified earlier to significantly enable injury recovery compared to placebo. This study evaluates the role of rhuGSN for its antioxidant and wound healing properties in murine fibroblasts (3T3-L1 cell line). Total antioxidant capacity of rhuGSN increased in a concentration-dependent manner (0.75-200 μg/mL). Cells pretreated with 0.375 and 0.75 μg/mL rhuGSN for 24 h exhibited a significant increase in viability in a MTT assay. Preincubation of cells with rhuGSN for 24 h followed by oxidative stress induced by exposure to H2O2 for 3 h showed cytoprotective effect. rhuGSN at 12.5 and 25 μg/mL concentration showed an enhanced cell migration after 20 h of injury in a scratch wound healing assay. The proinflammatory cytokine IL-6 levels were elevated in the culture supernatant. These results establish an effective role of rhuGSN against oxidative stress induced by H2O2 and in wound healing of 3T3-L1 fibroblast cells.

scholarly journals Increased Anti-Inflammatory Effects on LPS-Induced Microglia Cells by Spirulina maxima Extract from Ultrasonic Process

2019 ◽  
Vol 9 (10) ◽  
pp. 2144 ◽  
Author(s):  
Woon Yong Choi ◽  
Jae-Hun Sim ◽  
Jung-Youl Lee ◽  
Do Hyung Kang ◽  
Hyeon Yong Lee
Keyword(s):  
Mrna Expression ◽  
Dependent Manner ◽  
Spirulina Maxima ◽  
Concentration Dependent Manner ◽  
Quantitative Correlation ◽  
Tnf Α ◽  
Ultrasonic Process ◽  
Anti Inflammatory ◽  
Low Cytotoxicity ◽  
High Concentrations

The Spirulina maxima exact from a non-thermal ultrasonic process (UE) contains 17.5 mg/g of total chlorophyll, compared to 6.24 mg/g of chlorophyll derived from the conventional 70% ethanol extraction at 80 °C for 12 h (EE). The UE also showed relatively low cytotoxicity against murine microglial cells (BV-2) and inhibited the production of the inflammatory mediators, NO and PGE2. The UE also effectively suppresses both mRNA expression and the production of pro-inflammatory cytokines, such as TNF-α, IL-6 and IL-1β, in a concentration-dependent manner. Notably, TNF-α gene and protein production were most strongly down-regulated, while IL-6 was the least affected by all ranges of treatment concentrations. This work first demonstrated a quantitative correlation between mRNA expression and the production of cytokines, showing that suppression of TNF-α gene expression was most significantly correlated with its secretion. These results clearly proved that the anti-inflammatory effects of Spirulina extract from a nonthermal ultrasonic process, which yielded high concentrations of intact forms of chlorophylls, were increased two-fold compared to those of conventional extracts processed at high temperature.

scholarly journals Polyhydroxyfullerene Binds Cadmium Ions and Alleviates Metal-Induced Oxidative Stress in Saccharomyces cerevisiae

2014 ◽  
Vol 80 (18) ◽  
pp. 5874-5881 ◽  
Author(s):  
Arunava Pradhan ◽  
José Paulo Pinheiro ◽  
Sahadevan Seena ◽  
Cláudia Pascoal ◽  
Fernanda Cássio
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Antioxidant Properties ◽  
Water Soluble ◽  
Interactive Effects ◽  
Membrane Disruption ◽  
Dependent Manner ◽  
Extracellular Medium ◽  
Cadmium Ions ◽  
Ph Dependent

ABSTRACTThe water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeastSaccharomyces cerevisiaeby exposing cells to Cd (≤5 mg liter−1) in the absence or presence of PHF (≤500 mg liter−1) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.

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