Factors affecting in vitro and in vivo antioxidant effects. Experimental conditions and nature of oxidants determine antioxidant efficacy

2021 ◽  
pp. 1-9
Author(s):  
Etsuo Niki
Keyword(s):  
Biological Molecules ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Beneficial Effects ◽  
Multiple Oxidants ◽  
Antioxidant Effects

Reactive oxygen and nitrogen species have been implicated in the onset and progression of various diseases and the role of antioxidants in the maintenance of health and prevention of diseases has received much attention. The action and effect of antioxidants have been studied extensively under different reaction conditions in multiple media. The antioxidant effects are determined by many factors. This review aims to discuss several important issues that should be considered for determination of experimental conditions and interpretation of experimental results in order to understand the beneficial effects and limit of antioxidants against detrimental oxidation of biological molecules. Emphasis was laid on cell culture experiments and effects of diversity of multiple oxidants on antioxidant efficacy.

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

scholarly journals Antioxidant Properties of Ergosterol and Its Role in Yeast Resistance to Oxidation

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1024
Author(s):  
Sebastien Dupont ◽  
Paul Fleurat-Lessard ◽  
Richtier Gonçalves Cruz ◽  
Céline Lafarge ◽  
Cédric Grangeteau ◽  
...  
Keyword(s):  
Computational Study ◽  
Antioxidant Properties ◽  
Beneficial Effects ◽  
Tert Butyl Hydroperoxide ◽  
Resistance To Oxidation ◽  
Specific Accumulation ◽  
The Subject

Although the functions and structural roles of sterols have been the subject of numerous studies, the reasons for the diversity of sterols in the different eukaryotic kingdoms remain unclear. It is thought that the specificity of sterols is linked to unidentified supplementary functions that could enable organisms to be better adapted to their environment. Ergosterol is accumulated by late branching fungi that encounter oxidative perturbations in their interfacial habitats. Here, we investigated the antioxidant properties of ergosterol using in vivo, in vitro, and in silico approaches. The results showed that ergosterol is involved in yeast resistance to tert-butyl hydroperoxide and protects lipids against oxidation in liposomes. A computational study based on quantum chemistry revealed that this protection could be related to its antioxidant properties operating through an electron transfer followed by a proton transfer mechanism. This study demonstrates the antioxidant role of ergosterol and proposes knowledge elements to explain the specific accumulation of this sterol in late branching fungi. Ergosterol, as a natural antioxidant molecule, could also play a role in the incompletely understood beneficial effects of some mushrooms on health.

scholarly journals Metformin-stimulated AMPK-α1 promotes microvascular repair in acute lung injury

2013 ◽  
Vol 305 (11) ◽  
pp. L844-L855 ◽  
Author(s):  
Ming-Yuan Jian ◽  
Mikhail F. Alexeyev ◽  
Paul E. Wolkowicz ◽  
Jaroslaw W. Zmijewski ◽  
Judy R. Creighton
Keyword(s):  
Endothelial Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Ex Vivo ◽  
Endothelial Permeability ◽  
Beneficial Effects ◽  
Isolated Lung

Acute lung injury secondary to sepsis is a leading cause of mortality in sepsis-related death. Present therapies are not effective in reversing endothelial cell dysfunction, which plays a key role in increased vascular permeability and compromised lung function. AMP-activated protein kinase (AMPK) is a molecular sensor important for detection and mediation of cellular adaptations to vascular disruptive stimuli. In this study, we sought to determine the role of AMPK in resolving increased endothelial permeability in the sepsis-injured lung. AMPK function was determined in vivo using a rat model of endotoxin-induced lung injury, ex vivo using the isolated lung, and in vitro using cultured rat pulmonary microvascular endothelial cells (PMVECs). AMPK stimulation using N1-(α-d-ribofuranosyl)-5-aminoimidizole-4-carboxamide or metformin decreased the LPS-induced increase in permeability, as determined by filtration coefficient ( Kf) measurements, and resolved edema as indicated by decreased wet-to-dry ratios. The role of AMPK in the endothelial response to LPS was determined by shRNA designed to decrease expression of the AMPK-α1 isoform in capillary endothelial cells. Permeability, wounding, and barrier resistance assays using PMVECs identified AMPK-α1 as the molecule responsible for the beneficial effects of AMPK in the lung. Our findings provide novel evidence for AMPK-α1 as a vascular repair mechanism important in the pulmonary response to sepsis and identify a role for metformin treatment in the management of capillary injury.

scholarly journals Phytoestrogens: Dietary Intake, Bioavailability, and Protective Mechanisms against Colorectal Neoproliferative Lesions

Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1709 ◽  
Author(s):  
Maria Teresa Viggiani ◽  
Lorenzo Polimeno ◽  
Alfredo Di Leo ◽  
Michele Barone
Keyword(s):  
Dietary Intake ◽  
Intestinal Microbiota ◽  
Estrogen Receptor Beta ◽  
Epidemiological Data ◽  
In Vivo Studies ◽  
Beneficial Effects ◽  
Natural Substances

Phytoestrogens are natural substances that have been extensively studied for their beneficial effect on human health. Herein, we analyzed the data of the literature on the role of phytoestrogens in the prevention of colorectal neoproliferative lesions (CNL). Both in vitro and in vivo studies suggest that the beneficial effects of phytoestrogens on CNL mainly depend on their ability to bind estrogen receptor beta (ERβ) in the intestinal mucosa and counter ER-alpha (ERα) activity. Epidemiological data demonstrate a correlation between the low prevalence of CNL in Eastern populations and the consumption of soy products (phytoestrogen-enriched diet). However, both observational and interventional studies have produced inconclusive results. In our opinion, these discrepancies depend on an inadequate evaluation of phytoestrogen intake (dietary questionnaires were not aimed at establishing phytoestrogen intake) and absorption (depending mainly on the intestinal microbiota of the analyzed subjects). For this reason, in the present review, we performed an overview of phytoestrogen dietary intake and metabolism to offer the reader the opportunity for a better interpretation of the literature. Future prospective trials focusing on the protective effect of phytoestrogens against CNL should take into account both their dietary intake and absorption, considering the effective role of the intestinal microbiota.

Fructose Phosphorylation and Dephosphorylation by the Intestinal Mucosa of the Rat During Fructose Absorption

1957 ◽  
Vol 189 (2) ◽  
pp. 301-306 ◽  
Author(s):  
Nicholas M. Papadopoulos ◽  
Joseph H. Roe
Keyword(s):  
Intestinal Mucosa ◽  
Phosphate Esters ◽  
Reduction Techniques ◽  
Mucosal Cells ◽  
Normal Metabolism ◽  
Fasted Rats

The role of phosphorylation in the absorption of fructose from the intestinal tract of the fasted rat by in vitro and in vivo techniques was studied. The authors' method for the determination of fructose phosphate esters was used and these esters were identified by paper chromatography and copper reduction techniques. Buffered homogenate of intestinal mucosa of a fasted rat, mixed with ATP, MgCl2, KF and fructose, when incubated at 30°, showed the formation of fructose-6-phosphate and fructose-1, 6-diphosphate at a rate that corresponded to the decrease in free fructose. The same homogenate, mixed with fructose-1, 6-diphosphate and incubated at 37°, showed the formation of fructose-6-phosphate and free fructose at a rate that corresponded to the decrease in the concentration of the diphosphate ester. Following intraduodenal injection of fructose solution into anesthetized fasted rats, homogenates of the intestinal mucosa showed the presence of fructose-6-phosphate and fructose-1, 6-diphosphate in average concentrations 14 and 5 times, respectively, those found in control muocsa, also concentrations of free fructose in the blood of the portal vein up to 24.6 mg % were observed. The large increase in fructose phosphate esters in the intestinal mucosa, observed after fructose administration, suggests that phosphorylation of sugars in absorption serves a more extensive function than to initiate glycolysis for the normal metabolism of the mucosal cells. The data obtained suggest that phosphorylation and dephosphorylation are functional steps in the absorption of fructose from the alimentary tract of the rat.

Effects of exercise on endothelium and endothelium/smooth muscle cross talk: role of exercise-induced hemodynamics

2011 ◽  
Vol 111 (1) ◽  
pp. 311-320 ◽  
Author(s):  
S. C. Newcomer ◽  
Dick H. J. Thijssen ◽  
D. J. Green
Keyword(s):  
Physical Activity ◽  
Shear Stress ◽  
Wall Stress ◽  
Beneficial Effects ◽  
Exercise Induced ◽  
Response To Exercise ◽  
And Training

Physical activity, exercise training, and fitness are associated with decreased cardiovascular risk. In the context that a risk factor “gap” exists in the explanation for the beneficial effects of exercise on cardiovascular disease, it has recently been proposed that exercise generates hemodynamic stimuli which exert direct effects on the vasculature that are antiatherogenic. In this review we briefly introduce some of the in vitro and in vivo evidence relating exercise hemodynamic modulation and vascular adaptation. In vitro data clearly demonstrate the importance of shear stress as a potential mechanism underlying vascular adaptations associated with exercise. Supporting this is in vivo human data demonstrating that exercise-mediated shear stress induces localized impacts on arterial function and diameter. Emerging evidence suggests that exercise-related changes in hemodynamic stimuli other than shear stress may also be associated with arterial remodeling. Taken together, in vitro and in vivo data strongly imply that hemodynamic influences combine to orchestrate a response to exercise and training that regulates wall stress and peripheral vascular resistance and contributes to the antiatherogenic impacts of physical activity, fitness, and training.

scholarly journals Dietary compounds as potential modulators of microRNA expression in psoriasis

2019 ◽  
Vol 10 ◽  
pp. 204062231986480 ◽  
Author(s):  
Hristina Kocic ◽  
Giovanni Damiani ◽  
Bojana Stamenkovic ◽  
Michael Tirant ◽  
Andrija Jovic ◽  
...  
Keyword(s):  
Vitamin D ◽  
Omega 3 ◽  
Experimental Conditions ◽  
Keratinocyte Proliferation ◽  
Methyl Donors ◽  
Beneficial Effects ◽  
Small Noncoding Rnas ◽  
The Impact

Nutrigenomic DNA reprogramming in different chronic diseases and cancer has been assessed through the stimulation of gene expression and mRNA synthesis versus DNA silencing by CpG DNA modification (methylation); histone modification (acetylation, methylation) and expression of small noncoding RNAs, known as microRNAs (miRNAs). With regard to the specific nutrigenomic effects in psoriasis, the influence of specific diets on inflammatory cell signaling transcriptional factors such as nuclear factor (NF)-κB and Wnt signaling pathways, on disease-related specific cytokine expression, pro/antioxidant balance, keratinocyte proliferation/apoptosis and on proliferation/differentiation ratio have been documented; however, the influence of dietary compounds on the balance between ‘good and bad’ miRNA expression has not been considered. This review aims to summarize knowledge about aberrant microRNAs expression in psoriasis and to emphasize the potential impact of some dietary compounds on endogenous miRNA synthesis in experimental conditions in vivo and in vitro. Among the aberrantly expressed miRNAs in psoriasis, one of the most prominently upregulated seems to be miR-21. The beneficial effects of phenolic compounds (curcumin and resveratrol), vitamin D, methyl donors, and omega-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) are discussed. Highly expressed miR-155 has been downregulated by flavonoids (through a quercetin-rich diet) and by vitamin D. Quercetin has been effective in modulating miR-146a. On the other hand, downregulated miR-125b expression was restored by vitamin D, Coenzyme Q10 and by microelement selenium. In conclusion, the miRNA profile, together with other ‘omics’, may constitute a multifaceted approach to explore the impact of diet on psoriasis prevention and treatment.

THE ROLE OF A 3-0 SULFO GROUP IN THE GLUCOSAMINE RESIDUE OF A SYNTHETIC OLIGOSACCHARIDE FOR THE DETERMINATION OF ANTITHROMBOTIC ACTIONS

1987 ◽  
Author(s):  
J M Walenga ◽  
J Fareed ◽  
M Petitou ◽  
J C Lormeau ◽  
M Samama ◽  
...  
Keyword(s):  
Sulfo Group ◽  
Factor Xa ◽  
Antithrombotic Effect ◽  
Antithrombotic Activity ◽  
Thrombosis Model ◽  
Factor Xa Inhibition

We have previously reported on the antithromboticaction of a chemically synthesized heparin pentasaccharide which exhibits high affinity to anti thrombinIII and sole anti-factor Xa activity. In order to investigate the relative importance of the 3-0 sulfo group of this pentasaccharide, we evaluated the in vitro and in vivo antithrombotic activity of a synthetic pentasccharide devoid of the sulfo group at the third position of the glucosamine residue. In amidolytic and clot-based assays the 3-0 de- sulfated pentasaccharide (3-0-DP) failed to exhibit any antifactor Xa actions at concentrations <100 ug/ml in humanor rabbit plasmas, whereas pentasaccharide showed strong factor Xa inhibition at 1.0 ug/ml IK-=3.2x10 M)and at 10.0 ug/ml in rabbit plasma (K.=9.0×10™7 M). Using a rabbit stasis thrombosis model in which thrombosis was induce by human serum or an activated pro-thrombin complex concentrate, 3-0-DP failed to produce any antithrombotic action in acute intravenous regimens at dosages up to 200 ug/kg. In these two models, pentasaccharide produced >80% inhibition of induced thrombosis. These studies demonstrate the critical importance of the 3-0 sulfo group in this heparin pentasaccharide for the determination of antithrombotic activity, and that in this type of oligosaccharide, anti-factor Xa activity is responsible for producing the antithrombotic effect.

Anionic and cationic exchange mechanisms in the skin of anurans, with special reference to Leptodactylidae in vivo

1971 ◽  
Vol 262 (842) ◽  
pp. 163-174 ◽  
Keyword(s):  
Transport Mechanism ◽  
Selective Inhibition ◽  
The Other ◽  
Sodium Absorption ◽  
Experimental Conditions ◽  
Net Flux ◽  
Cationic Exchange

In several species of anurans, the in vivo skin has been shown to absorb Na + and Cl - independently from dilute external solutions. That the mechanism for sodium absorption is different from that of chloride absroption is born out by the following: (1) Either of these ions is absorbed without an accompanying ion when this latter is impermeant. (2) From NaCl solutions there can be an unequal absorption of sodium and chloride. (3) A selective inhibition of the absorption of one of the ions can be produced experimentally, while the net flux of the other remains unchanged. In all these situations, the absorbed ion has to be exchanged against an endogenous ion of the same charge. In Calyptocephalella gayi , H + and HCO - 3 are exchanged against sodium and chloride respectively. A comparison of the relationships between H + excretion and Na + absorption in vivo skins and shortcircuited in vitro skins shows that in the latter no H + excretion occurs, only the Na + transport being maintained under these experimental conditions. From this, one must conclude that the active Na + transport is the motive factor of the transport mechanism. H + excretion by the in vivo skin plays the role of physiologically short-circuiting the Na + transport.

scholarly journals The Role of DPP4 Activity in Cardiovascular Districts: In Vivo and In Vitro Evidence

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
L. Pala ◽  
C. M. Rotella
Keyword(s):  
Minimal Risk ◽  
Incretin Hormone ◽  
Dipeptidyl Peptidase 4 ◽  
Beneficial Effects ◽  
Positive Effects ◽  
Glucagon Like Peptide 1 ◽  
A Site

The introduction of incretin hormone-based therapies represents a novel therapeutic strategy, since these drugs not only improve glycemia with minimal risk of hypoglycemia, but also have other extraglycemic beneficial effects. These agents, which are effective in improving glucose control, could also have positive effects on the incidence of cardiovascular events. The aim of this review is to summarize the present literature about the role of dipeptidyl peptidase 4 (DPP4) in cardiovascular districts, not only strictly correlated to its effect on glucagon-like peptide-1 (GLP-1) circulating levels, but also to what is known about possible cardiovascular actions. Actually, DPP4 is known to be present in many cells and tissues and its effects go beyond purely metabolic aspects. Almost always the inhibition of DPP4 activity is associated with improved cardiovascular profile, but it has shown to possess antithrombotic properties and these different effects could be connected with a site and/or species specificity of DPP4. Certainly, DPP4 seems to exert many functions, both directly and indirectly, on cardiovascular districts, opening new possibilities of prevention and treatment of complications at this level, not only in patients affected by diabetes mellitus.

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