scholarly journals In vitro antiviral activity and kinetics of the inhibitory effect of some compounds against Feline calicivirus strain F9 – a surrogate model of human noroviruses

2018 ◽  
pp. 55-60
Keyword(s):  
Antiviral Activity ◽  
Surrogate Model ◽  
Inhibitory Effect ◽  
Feline Calicivirus ◽  
Human Noroviruses ◽  
Kinetics Of

Amiodarone induces stress responses and calcium flux mediated by the cell wall in Saccharomyces cerevisiae

2009 ◽  
Vol 55 (3) ◽  
pp. 288-303 ◽  
Author(s):  
William E. Courchesne ◽  
Meral Tunc ◽  
Sha Liao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Stress Responses ◽  
Inhibitory Effect ◽  
Calcium Flux ◽  
Yeast Saccharomyces Cerevisiae ◽  
Proteomic Approach ◽  
Amiodarone Treatment ◽  
Kinetics Of

We used a proteomic approach to study effects of amiodarone on cells of the yeast Saccharomyces cerevisiae. Amiodarone has been shown to have antifungal activity in vitro and causes a massive increase in cytoplasmic calcium levels ([Ca2+]cyt). Proteomic analysis of cells exposed to amiodarone show that this drug elicits stress responses and points to involvement of proteins associated with the cell wall. We tested several of those proteins for involvement in the Ca2+ flux. In particular, the amiodarone-induced Ca2+ flux was decreased in bgl2Δ cells, which have altered levels of β-glucan and chitin. The involvement of the cell wall in the Ca2+ flux induced by amiodarone treatment was tested by addition of yeast cell-wall components. While mannan inhibited the rise in [Ca2+]cyt, β-glucan potentiated the Ca2+ flux by 4.5-fold, providing evidence that the cell wall is directly involved in controlling this Ca2+ flux. This conclusion is corroborated by the inhibition of the Ca2+ flux by calcofluor, which is known to bind to cell-wall chitin and inhibit cell growth. Zymolyase treatment altered the kinetics of amiodarone-induced calcium flux and uncoupled the inhibitory effect of calcofluor. These effects demonstrate that the cell-wall β-glucan regulates calcium flux elicited by amiodarone.

scholarly journals Antiviral Activity ofIsatis indigoticaExtract and Its Derived Indirubin against Japanese Encephalitis Virus

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shu-Jen Chang ◽  
Yi-Chih Chang ◽  
Kai-Zen Lu ◽  
Yi-Yun Tsou ◽  
Cheng-Wen Lin
Keyword(s):  
Antiviral Activity ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Antiviral Effect ◽  
Inhibitory Effect ◽  
Encephalitis Virus ◽  
Simultaneous Treatment ◽  
Virus Attachment ◽  
Antiviral Activities

Isatis indigoticais widely used in Chinese Traditional Medicine for clinical treatment of virus infection, tumor, and inflammation, yet its antiviral activities remain unclear. This study probed antiviral activity ofI. indigoticaextract and its marker compounds against Japanese encephalitis virus (JEV).I. indigoticamethanol extract, indigo, and indirubin proved less cytotoxic than other components, showing inhibitory effect (concentration-dependent) on JEV replicationin vitro. Time-of-addition experiments proved the extract, indigo, and indirubin with potent antiviral effect by pretreatment (before infection) or simultaneous treatment (during infection), but not posttreatment (after entry). Antiviral action of these agents showed correlation with blocking virus attachment and exhibited potent virucidal activity. In particular, indirubin had strong protective ability in a mouse model with lethal JEV challenge. The study could yield anti-JEV agents.

Antiviral Activity of Some Hydroxycoumarin Derivatives

1996 ◽  
Vol 51 (7-8) ◽  
pp. 558-562 ◽  
Author(s):  
Angel S. Galabov ◽  
Tanya Iosifova ◽  
Elka Vassileva ◽  
Ivanka Kostova
Keyword(s):  
Antiviral Activity ◽  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Virus Replication ◽  
Cell Cultures ◽  
Newcastle Disease ◽  
Inhibitory Effect ◽  
Marked Inhibitory Effect ◽  
Herpès Virus

Abstract Esculetin (6,7-dihydroxycoumarin) and its diacetate exhibited a marked inhibitory effect on Newcastle disease virus replication in cell cultures at concentrations of 36 jam and 62 jam, respectively. These compounds were selected from ten hydroxycoumarin derivatives through an in vitro antiviral screen involving viruses of the picorna-, orthomyxo-, paramyxo-, and herpes virus families.

scholarly journals In Vitro Antimicrobial, Antiviral and Cytotoxicity Activities of Aspergillus oryzae Isolated From El-Baida Marsh in Algeria

2020 ◽  
Vol 10 (4) ◽  
pp. 191-195
Author(s):  
Nacef Houda Sara ◽  
Belhattab Rachid ◽  
Galvez Julio ◽  
Rodriguez-Sojo María Jesus ◽  
Vezza Teresa
Keyword(s):  
Antimicrobial Activity ◽  
Antiviral Activity ◽  
Aspergillus Oryzae ◽  
Antimicrobial Property ◽  
Inhibition Zone ◽  
Inhibitory Effect ◽  
Host Cells ◽  
Minimal Inhibitory Concentrations ◽  
Cytotoxicity Activity

This work covers the study of antimicrobial and antiviral activities of the Aspergillus oryzae strain isolated from saline soil (El-Baida marsh in Algeria). The crude extract obtained with ethyl acetate displayed antimicrobial activity against Gram-positive and Gram-negative bacteria and the yeast Candida albicans with a mean of 16.69 mm of inhibition zone and a minimal inhibitory concentrations MICs between 7.28 and 21.85 μgmL-1. We also assessed the antiviral activity against Herpes simplex-2 Virus (HSV-2), in which no inhibitory effect was exhibited. In addition, cytotoxicity activity was tested in Caco-2 and RAW 264, a human epithelial and a murine macrophage cell line, respectively, revealing a no-toxic effect of the extract. The studied isolate extract possesses an antimicrobial property and its non-toxicity to the host cells becomes very important, and can be exploited for the production of new pharmacological and biotechnological agents.        Keywords: Aspergillus oryzae, antimicrobial activity, antiviral activity, cytotoxicity, fungal extraction.

scholarly journals Screening of in vitro antiviral activity of purified terpenoid extracts of selected sea weeds against chikungunya virus

2020 ◽  
pp. 320-324
Author(s):  
Sabira Siraj Sumayya ◽  
Abdulhadeef Shereefa Lubaina ◽  
Kumaraswamy Murugan
Keyword(s):  
Antiviral Activity ◽  
Chikungunya Virus ◽  
Kappaphycus Alvarezii ◽  
Inhibitory Effect ◽  
Hypnea Musciformis ◽  
High Incidence ◽  
Medicinal Properties ◽  
Inhibitory Potential ◽  
Layer Chromatography

Currently, the search of novel phytochemicals with unique biological potentialities is a pre-requisite for the designing ideal drugs for the human kind. Sea weeds are bioresources with a broad spectrum of medicinal properties with minimal side effects. Kerala, the Southern state of India reported high incidence of Chikungunya virus (CHIKV) infections in the last several tears. No specific virucidal therapy or effective vaccines are available. This emphasizes the need of searching for phytochemicals as drugs with less cost and more effective. Therefore, an attempt was made in screening purified terpenoid extracts of selected sea weeds as anti-CHIKV potential. In this study the terpenoids composition from the red algae Hypnea musciformis, Kappaphycus alvarezii and Gracillaria dura were identified and analyzed by thin layer chromatography and Gas chromatography- Mass spectrum. The methanolic extract of seaweeds was purified by column chromatography and each fraction was eluted by using petroleum ether and ethyl acetate as solvent combination. The analysis of the purified fraction of H. musciformis and K. alvarezii revealed the presence of 8 terpenoid fractions, and G. dura showed only 4 major components respectively. Vero cell lines were employed in the antiviral assays, infected to CHIKV, and treated with varied doses of purified terpenoid extracts. In the antiviral activity, terpenoid extracts of G. dura showed remarkable and promising EC50 inhibitory effect at 1.25 μg/ml. Further, the terpenoid extracts displayed efficient virucidal activity against CHIKV (inhibit around 90%) with 5 μg/ml dosage. As the last phase, terpenoid extracts added at time intervals of 0, 1, 2, 3 post-infection periods still maintained a significant inhibitory potential against CHIKV viral replication. Thus, the overall study suggests that the terpenoid extracts of G. dura may be effectively used in the prevention and treatment of CHIKV infections. Clinical studies may be warranted for designing a promising new anti-CHIKV drug.

scholarly journals Ribavirin shows antiviral activity against SARS-CoV-2 and downregulates the activity of TMPRSS2 and the expression of ACE2 in vitro

2021 ◽  
pp. 1-12 ◽  
Author(s):  
Mehmet Altay Unal ◽  
Ceylan Verda Bitirim ◽  
Gokce Yagmur Summak ◽  
Sidar Bereketoglu ◽  
Inci Cevher Zeytin ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Broad Spectrum ◽  
In Silico ◽  
Antiviral Drug ◽  
In Silico Analysis ◽  
Cell Types ◽  
Suppressive Effect ◽  
Inhibitory Effect ◽  
Molecular Techniques

Ribavirin is a guanosine analog with broad-spectrum antiviral activity against RNA viruses. Based on this, we aimed to show the anti-SARS-CoV-2 activity of this drug molecule via in vitro, in silico, and molecular techniques. Ribavirin showed antiviral activity in Vero E6 cells following SARS-CoV-2 infection, whereas the drug itself did not show any toxic effect over the concentration range tested. In silico analysis suggested that ribavirin has a broad-spectrum impact on SARS-CoV-2, acting at different viral proteins. According to the detailed molecular techniques, ribavirin was shown to decrease the expression of TMPRSS2 at both mRNA and protein levels 48 h after treatment. The suppressive effect of ribavirin in ACE2 protein expression was shown to be dependent on cell types. Finally, proteolytic activity assays showed that ribavirin also showed an inhibitory effect on the TMPRSS2 enzyme. Based on these results, we hypothesized that ribavirin may inhibit the expression of TMPRSS2 by modulating the formation of inhibitory G-quadruplex structures at the TMPRSS2 promoter. As a conclusion, ribavirin is a potential antiviral drug for the treatment against SARS-CoV-2, and it interferes with the effects of TMPRSS2 and ACE2 expression.

Uptake of a Series of Neutral Dipeptides Including l-Alanyl-l-Alanine, Glycylglycine and Glycylsarcosine by Hamster Jejunum in Vitro

1984 ◽  
Vol 67 (5) ◽  
pp. 541-549 ◽  
Author(s):  
D. M. Matthews ◽  
D. Burston
Keyword(s):  
Amino Acids ◽  
Free Amino ◽  
Inhibitory Effect ◽  
Progressive Increase ◽  
The Other ◽  
Uptake System ◽  
Apparent Affinity ◽  
Inhibitory Ability ◽  
Kinetics Of

1. This paper is the last of a set reporting an investigation of the kinetics of jejunal uptake and inhibitory ability of a series of neutral dipeptides, glycylglycine, l-ananyl-l-alanine, l-valyl-l-valine and l-leucyl-l-leucine, with progressively longer and more lipophilic side chains. 2. The results suggested that at pH 5, uptake of l-alanyl-l-alanine, like that of l-valyl-l-valine and l-leucyl-l-leucine, was the result of two processes, uptake of intact peptide and uptake of free amino acid released extracellularly. On the other hand, uptake of glycylglycine was entirely in the form of intact peptide. In contrast to uptake of l-valyl-l-valine and l-leucyl-l-leucine, the proportion of intact l-alanyl-l-alanine taken up by mediated transport was greatest at the lowest concentration studied and smallest at the highest concentration. 3. Taking the series of results as a whole, whereas the corresponding series of amino acids, glycine, l-alanine, l-valine and l-leucine, showed a progressive increase in apparent affinity for uptake and a decrease in Vmax., we could find no such regular progression with the peptides. 4. The results of work on inhibition of uptake of one dipeptide by another were unexpectedly complex. Examples were the very powerful inhibitory effect of l-valyl-l-valine on uptake of glycylsarcosine, not suggested by the Kt of the former peptide, and the failure of glycylsarcosine to cause complete inhibition of uptake of l-alanyl-l-alanine and l-leucyl-l-leucine, though it could completely inhibit uptake of l-valyl-l-valine. There may be more than one uptake system for intact peptides, but we cannot yet suggest an explanation for all the results on inhibitions of uptake.

Alteration of the pharmacokinetics of high-dose ara-C by its metabolite, high ara-U in patients with acute leukemia.

1983 ◽  
Vol 1 (12) ◽  
pp. 763-771 ◽  
Author(s):  
R L Capizzi ◽  
J L Yang ◽  
E Cheng ◽  
T Bjornsson ◽  
D Sahasrabudhe ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Cytosine Arabinoside ◽  
Half Life ◽  
Disease Status ◽  
Inhibitory Effect ◽  
High Dose ◽  
Elimination Half ◽  
Kinetics Of ◽  
Time Of Administration

The pharmacokinetics of high-dose cytosine arabinoside (HiDAC) given as a three-hour intravenous infusion at 3 g/m2 were studied in five patients with acute leukemia during relapse and/or remission of their disease. Apparent steady state plasma levels of ara-C during 13 infusions averaged 115 +/- 32 microM. Upon cessation of the infusion, cytosine arabinoside (ara-C) was rapidly cleared from the plasma. The apparent postinfusion kinetics of ara-C were triexponential with a distribution half-life of 16 minutes and elimination half-lives of 1.8 hours and six hours. Total clearance averaged 86 L per hour and mean residence time averaged 0.47 hours. Disease status (relapse or remission) had no apparent effect on the pharmacokinetic characteristics of ara-C. Peak levels of ara-U averaged 310 microM and the metabolite had an average apparent elimination half-life of 3.75 hours. Despite the persistence of ara-U at about 100 microM at the time of administration of subsequent infusions of ara-C, there was no further accumulation of ara-U in the plasma with repetitive infusions of HiDAC. In vitro studies indicate that ara-U can exert an inhibitory effect on deoxycytidine (dCyd) deaminase activity. The ratio of the Ki of ara-U to the Km of ara-C for cytidine (Cyd)-dCyd deaminase is 40:1; however, during the gamma phase of ara-C elimination, the ratio of ara-U:ara-C in plasma is at least 100:1. Thus, a retardation of systemic catabolism of ara-C by ara-U is possible. Two to three hours after the termination of the HiDAC infusion, the ara-C cerebrospinal fluid: plasma ratio is 1-3:1, a feature of potential therapeutic significance. The slower elimination of ara-C from the CSF may also contribute to the plasma gamma half-life.

scholarly journals A rational approach to identifying effective combined anticoronaviral therapies against feline coronavirus

2020 ◽  
Author(s):  
S.E. Cook ◽  
H. Vogel ◽  
D. Castillo ◽  
M. Olsen ◽  
N. Pedersen ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Viral Replication ◽  
Clinical Signs ◽  
Treatment Strategies ◽  
Antiviral Effect ◽  
Inhibitory Effect ◽  
Rational Approach ◽  
Neurological Involvement ◽  
Ocular Involvement

AbstractFeline infectious peritonitis (FIP), caused by a genetic mutant of feline enteric coronavirus known as FIPV, is a highly fatal disease of cats with no currently available vaccine or FDA-approved cure. Dissemination of FIPV in affected cats results in a range of clinical signs including cavitary effusions, anorexia, fever and lesions of pyogranulomatous vasculitis and peri-vasculitis with or without central nervous system and/or ocular involvement. There is a critical need for effective and approved antiviral therapies against coronaviruses including FIPV and zoonotic coronaviruses such as SARS-CoV-2, the cause of COVID-19. With regards to SARS-CoV-2, preliminary evidence suggests that there may be potential clinical and pathological overlap with feline coronaviral disease including enteric and neurological involvement in some cases. We have screened 89 putative antiviral compounds and have identified 25 compounds with antiviral activity against FIPV, representing a variety of drug classes and mechanisms of antiviral action. Based upon successful combination treatment strategies for human patients with HIV or hepatitis C virus infections, we have identified combinations of drugs targeting different steps of the FIPV life cycle resulting in synergistic antiviral effect. Translationally, we suggest that a combined anticoronaviral therapy (cACT) with multiple mechanisms of action and penetration of all potential anatomic sites of viral infection should be applied towards other challenging to treat coronaviruses, like SARS-CoV-2.Author summaryWe have screened 89 compounds in vitro for antiviral activity against FIPV. The putative antiviral activity of these compounds was either purported to be a direct effect on viral proteins involved in viral replication or an indirect inhibitory effect on normal cellular pathways usurped by FIPV to aid viral replication. Twenty-five of these compounds were found to have significant antiviral activity. Certain combinations of these compounds were determined to be superior to monotherapy alone.

scholarly journals In vitro Activity of Polyhydroxycarboxylates against Herpesviruses and Hiv

2001 ◽  
Vol 12 (6) ◽  
pp. 337-345 ◽  
Author(s):  
Astrid Meerbach ◽  
Johan Neyts ◽  
Jan Balzarini ◽  
Björn Helbig ◽  
Erik De Clercq ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Sexual Transmission ◽  
Close Correlation ◽  
Inhibitory Effect ◽  
Host Cells ◽  
Virus Adsorption ◽  
Carboxylic Groups ◽  
Simplex Virus ◽  
Hsv 1

The antiviral activity of 17 polyhydroxycarboxylates derived from phenolic compounds was evaluated against herpesviruses and HIV. When present during virus adsorption several of the polymers exhibited potent activity against herpes simplex virus type 1 (HSV-1), HSV-2, thymidine kinase deficient HSV-1, human cytomegalovirus (HCMV) and HIV-1 and HIV-2 at concentrations that were not toxic to the host cells. A close correlation was found between the 50% inhibitory concentrations of the polyhydroxycarboxylates against HCMV-induced cytopathicity, their inhibitory effect on the expression of HCMV-specific immediate early antigens and their inhibitory effects on HCMV adsorption to the cells. The antiviral activity of the phenolic polymers was dependent on the presence of a sufficient number of carboxylic groups. The mechanism of antiviral action of the polyhydroxycarboxylates can thus be ascribed to inhibition of virus adsorption. This type of compound may have potential in a vaginal gel to prevent sexual transmission of HSV and HIV.

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