EFFECTS OF HEPARIN IN VIVO ON LYSOSOMAL ENZYMES IN RAT PLASMA

1967 ◽  
Vol 45 (7) ◽  
pp. 1145-1151 ◽  
Author(s):  
S. W. Levy
Keyword(s):  
Esterase Activity ◽  
Lysosomal Enzymes ◽  
Total Activity ◽  
Rat Plasma ◽  
Mechanisms Of Action ◽  
Specific Activities

Studies were carried out to determine the effects of heparin in vivo on acid ribonuclease, β-glucuronidase, acid β-glycerophosphatase, cathepsin, and several esterases in rat plasma. Increases occurred regularly in the specific activities of ribonuclease and β-glucuronidase, and inconsistently in that of acid β-glycerophosphatase. The activity of β-glucuronidase increased to a smaller extent in control animals. No change was observed in the activities of cathepsin or benzoylarginine ethyl esterase. Tributyrin esterase activity increased following the injection of heparin, the rise in total activity being due to an increase in the activities of both eserine-resistant and eserine-sensitive esterases in rat plasma. The results were discussed in terms of possible mechanisms of action of heparin and the significance of lysosomal enzymes in blood.

scholarly journals Mood Components in Cocoa and Chocolate: The Mood Pyramid

Planta Medica ◽  
2018 ◽  
Vol 84 (12/13) ◽  
pp. 839-844 ◽  
Author(s):  
Emmy Tuenter ◽  
Kenn Foubert ◽  
Luc Pieters
Keyword(s):  
Critical Appraisal ◽  
Mechanisms Of Action ◽  
Cocoa Beans ◽  
Minor Constituents ◽  
Specific Activities ◽  
Mood And Cognition ◽  
Cocoa Tree

AbstractCocoa and chocolate, prepared from cocoa beans that originate from the fruits of the cocoa tree Theobroma cacao, have a long-standing reputation as healthy food, including mood-enhancing effects. In spite of many clinical trials with chocolate, cocoa, or its constituents, the mechanisms of action on mood and cognition remain unclear. More in particular, it is still controversial which constituents may contribute to the psychopharmacological activities, ranging from the major cacao flavanols and methylxanthines to the minor amines, amides, and alkaloids. In this review a critical appraisal is made of recent studies on mood and cognition, with a special emphasis on analytical characterization of the test samples. It is concluded that the mood and cognition-enhancing effects of cocoa and chocolate can be ranked from more general activities associated with flavanols and methylxanthines, to more specific activities related to minor constituents such as salsolinol, with on top the orosensory properties of chocolate. Therefore, the “mood pyramid” of cocoa and chocolate is proposed as a new concept. To understand the role and interactions of the different major and minor constituents of cocoa, it is recommended that all test samples used in future in vitro, in vivo, or human studies should be phytochemically characterized in much more detail than is common practice today.

scholarly journals DEVELOPMENTAL STUDIES ON GLYOXYSOMES IN RICINUS ENDOSPERM

1970 ◽  
Vol 44 (1) ◽  
pp. 94-102 ◽  
Author(s):  
B. P. Gerhardt ◽  
Harry Beevers
Keyword(s):  
Enzyme Activities ◽  
Isocitrate Lyase ◽  
Total Activity ◽  
Early Growth ◽  
Soluble Form ◽  
Synthetase Activity ◽  
Developmental Studies ◽  
Lyase Activity ◽  
Specific Activities

The development of glyoxysomes and their associated enzymes, isocitrate lyase and malate synthetase, was studied in the endosperm of castor bean seeds during germination and early growth in darkness. The protein content of the glyoxysome fraction, separated by sucrose density centrifugation, increased linearly from day 2 to day 4 and declined subsequently, while maximum enzyme activities were reached at day 5. The specific activities of the enzymes in the glyoxysomes increased until day 5 and remained constant thereafter. At all stages of germination the only organelle with isocitrate lyase activity was the glyoxysome, but at the earlier stages a greater portion of the total activity was recovered in the soluble form. Malate synthetase was found primarily in the glyoxysomes after day 4, but at earlier stages part of the activity appeared at regions of lower density on the sucrose gradient. It was shown that this particulate malate synthetase activity was due to glyoxysomes broken during preparation, and that, as a result of this breakage, isocitrate lyase was solubilized. We conclude that both enzymes are housed in the glyoxysome in vivo throughout the germination period, and that the rise and fall in enzyme activities in phase with fat breakdown correspond to the net production and destruction of this organelle.

Mechanisms of action of antihyperglycemic mexicanolides isolated from Swietenia humillis: in vivo and in silico approaches

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381 ◽  
Author(s):  
B Ovalle-Magallanes ◽  
A Madariaga-Mazón ◽  
A Navarrete ◽  
R Mata
Keyword(s):  
In Silico ◽  
Mechanisms Of Action

Anti-thrombotic Effect of a PAI-1 Inhibitor in Rats Given Endotoxin

1996 ◽  
Vol 75 (01) ◽  
pp. 118-126 ◽  
Author(s):  
T Abrahamsson ◽  
V Nerme ◽  
M Strömqvist ◽  
B Åkerblom ◽  
A Legnehed ◽  
...  
Keyword(s):  
Plasminogen Activator Inhibitor ◽  
Rat Plasma ◽  
Clot Lysis ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Fab Fragment ◽  
Dose Dependent Decrease ◽  
Pai 1

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.

Accumulation of Human Apolipoprotein-E in Rat Plasma After in vivo Intramuscular Injection of Naked DNA

1994 ◽  
Vol 200 (1) ◽  
pp. 298-305 ◽  
Author(s):  
V.M. Fazio ◽  
S. Fazio ◽  
M. Rinaldi ◽  
M.V. Catani ◽  
S. Zotti ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Intramuscular Injection ◽  
Rat Plasma ◽  
Human Apolipoprotein ◽  
Naked Dna

scholarly journals Mining of high throughput screening database reveals AP-1 and autophagy pathways as potential targets for COVID-19 therapeutics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hu Zhu ◽  
Catherine Z. Chen ◽  
Srilatha Sakamuru ◽  
Jinghua Zhao ◽  
Deborah K. Ngan ◽  
...  
Keyword(s):  
Clinical Trials ◽  
High Throughput Screening ◽  
Animal Studies ◽  
Cytopathic Effect ◽  
Mechanisms Of Action ◽  
Activity Profile ◽  
Pathway Activity ◽  
Global Pandemic ◽  
Approved Drugs

AbstractThe recent global pandemic of the Coronavirus disease 2019 (COVID-19) caused by the new coronavirus SARS-CoV-2 presents an urgent need for the development of new therapeutic candidates. Many efforts have been devoted to screening existing drug libraries with the hope to repurpose approved drugs as potential treatments for COVID-19. However, the antiviral mechanisms of action of the drugs found active in these phenotypic screens remain largely unknown. In an effort to deconvolute the viral targets in pursuit of more effective anti-COVID-19 drug development, we mined our in-house database of approved drug screens against 994 assays and compared their activity profiles with the drug activity profile in a cytopathic effect (CPE) assay of SARS-CoV-2. We found that the autophagy and AP-1 signaling pathway activity profiles are significantly correlated with the anti-SARS-CoV-2 activity profile. In addition, a class of neurology/psychiatry drugs was found to be significantly enriched with anti-SARS-CoV-2 activity. Taken together, these results provide new insights into SARS-CoV-2 infection and potential targets for COVID-19 therapeutics, which can be further validated by in vivo animal studies and human clinical trials.

scholarly journals Chirality Matters: Biological Activity of Optically Pure Silybin and Its Congeners

2021 ◽  
Vol 22 (15) ◽  
pp. 7885
Author(s):  
Vladimír Křen
Keyword(s):  
Neurological Diseases ◽  
Biological Effects ◽  
Drug Metabolizing Enzymes ◽  
Metabolizing Enzymes ◽  
Biological Targets ◽  
Molecular Effects ◽  
Anisotropic Systems ◽  
Specific Activities ◽  
Optically Pure

This review focuses on the specific biological effects of optically pure silymarin flavo-nolignans, mainly silybins A and B, isosilybins A and B, silychristins A and B, and their 2,3-dehydro derivatives. The chirality of these flavonolignans is also discussed in terms of their analysis, preparative separation and chemical reactions. We demonstrated the specific activities of the respective diastereomers of flavonolignans and also the enantiomers of their 2,3-dehydro derivatives in the 3D anisotropic systems typically represented by biological systems. In vivo, silymarin flavonolignans do not act as redox antioxidants, but they play a role as specific ligands of biological targets, according to the “lock-and-key” concept. Estrogenic, antidiabetic, anticancer, antiviral, and antiparasitic effects have been demonstrated in optically pure flavonolignans. Potential application of pure flavonolignans has also been shown in cardiovascular and neurological diseases. Inhibition of drug-metabolizing enzymes and modulation of multidrug resistance activity by these compounds are discussed in detail. The future of “silymarin applications” lies in the use of optically pure components that can be applied directly or used as valuable lead structures, and in the exploration of their true molecular effects.

scholarly journals Development of 18F-Labeled Radiotracers for PET Imaging of the Adenosine A2A Receptor: Synthesis, Radiolabeling and Preliminary Biological Evaluation

2021 ◽  
Vol 22 (5) ◽  
pp. 2285
Author(s):  
Thu Hang Lai ◽  
Susann Schröder ◽  
Magali Toussaint ◽  
Sladjana Dukić-Stefanović ◽  
Mathias Kranz ◽  
...  
Keyword(s):  
Specific Binding ◽  
Brain Slices ◽  
Total Activity ◽  
Biological Evaluation ◽  
Adenosine A2a Receptor ◽  
Positron Emission ◽  
A2a Receptor ◽  
Adenosine A2a

The adenosine A2A receptor (A2AR) represents a potential therapeutic target for neurodegenerative diseases. Aiming at the development of a positron emission tomography (PET) radiotracer to monitor changes of receptor density and/or occupancy during the A2AR-tailored therapy, we designed a library of fluorinated analogs based on a recently published lead compound (PPY). Among those, the highly affine 4-fluorobenzyl derivate (PPY1; Ki(hA2AR) = 5.3 nM) and the 2-fluorobenzyl derivate (PPY2; Ki(hA2AR) = 2.1 nM) were chosen for 18F-labeling via an alcohol-enhanced copper-mediated procedure starting from the corresponding boronic acid pinacol ester precursors. Investigations of the metabolic stability of [18F]PPY1 and [18F]PPY2 in CD-1 mice by radio-HPLC analysis revealed parent fractions of more than 76% of total activity in the brain. Specific binding of [18F]PPY2 on mice brain slices was demonstrated by in vitro autoradiography. In vivo PET/magnetic resonance imaging (MRI) studies in CD-1 mice revealed a reasonable high initial brain uptake for both radiotracers, followed by a fast clearance.

scholarly journals Marine-Derived Compounds with Anti-Alzheimer’s Disease Activities

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 410
Author(s):  
Salar Hafez Ghoran ◽  
Anake Kijjoa
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Thinking Skills ◽  
Mechanisms Of Action ◽  
Brain Disorder ◽  
Brain Functioning ◽  
Pharmacologically Active ◽  
Pharmacologically Active Compounds

Alzheimer’s disease (AD) is an irreversible and progressive brain disorder that slowly destroys memory and thinking skills, and, eventually, the ability to perform simple tasks. As the aging population continues to increase exponentially, AD has become a big concern for society. Therefore, neuroprotective compounds are in the spotlight, as a means to tackle this problem. On the other hand, since it is believed—in many cultures—that marine organisms in an individual diet cannot only improve brain functioning, but also slow down its dysfunction, many researchers have focused on identifying neuroprotective compounds from marine resources. The fact that the marine environment is a rich source of structurally unique and biologically and pharmacologically active compounds, with unprecedented mechanisms of action, marine macroorganisms, such as tunicates, corals, sponges, algae, as well as microorganisms, such as marine-derived bacteria, actinomycetes, and fungi, have been the target sources of these compounds. Therefore, this literature review summarizes and categorizes various classes of marine-derived compounds that are able to inhibit key enzymes involved in AD, including acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), β-secretase (BACE-1), and different kinases, together with the related pathways involved in the pathogenesis of AD. The compounds discussed herein are emerging as promising anti-AD activities for further in-depth in vitro and in vivo investigations, to gain more insight of their mechanisms of action and for the development of potential anti-AD drug leads.

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