scholarly journals ANTIVIRAL ACTIVITY OF EXTRACT AND PURIFIED COMPOUND FROM RED MACROALGAE ASPARAGOPSIS TAXIFORMIS AGAINST H5N1 VIRUS

2021 ◽  
Author(s):  
Emad A. Shalaby ◽  
Sanaa M. M. Shanab
Keyword(s):  
Antiviral Activity ◽  
Peer Review ◽  
Active Compound ◽  
H5n1 Virus ◽  
Host Cells ◽  
Pure Compound ◽  
Red Macroalgae ◽  
Asparagopsis Taxiformis ◽  
Virus Adsorption ◽  
Pure Compounds

Aim and objective: The discovery and development of new natural antiviral compounds which exhibit various antiviral activities are required. The aim of this investigation is to assess the potential use of the red seaweed Asparagopsis taxiformis as a new source of anti H5N1 agent. Methods: The seaweed was collected from Marsa Matrouh, Mediterranean Sea, Egypt during spring season, the effects of successive extracts and the pure compounds from the investigated alga on H5N1 virus were performed using plaque reduction assay. In addition, the mechanism of action of promising extract on the virus adsorption and replication was determined. Chromatographic and spectroscopic analyses were used for the identification of chemical structure of active compound(s) isolated from the studied seaweed. Results: The obtained results showed that petroleum ether and water algal extracts exhibited high antiviral activity (>99.9%) and the mode of action of extracts was not correlated with virus replication but with its adsorption process.The isolated pure compound was identified as 6-methyl-Δ22-stigmasterol-2, 3 di acetate and its antiviral activity (for H5N1)was tested. Pure compound showed antiviral activity reached 56% at 100 µg/ml. Conclusion: The obtained results suggests that crude extracts and isolated active compound from A. taxiformis has the capacity to protect people against pandemic H5N1preventing virus adsorption to the human host cells. Recommendation for testing the extracts and pure compounds from the studied seaweed as potential inhibitor of COVID-19.                     Peer Review History: Received 16 March 2021; Revised 29 March; Accepted 21 April, Available online 15 May 2021 UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.  Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 8.0/10 Reviewer(s) detail: Prof. Dr. Hassan A.H. Al-Shamahy,  Sana'a University, Yemen, [email protected] Dr. Wadhah Hassan Ali Edrees, Hajja University, Yemen, [email protected]   Similar Articles: ANTIDIABETIC AND ANTIHYPERLIPIDEMIC ACTIVITY OF DRACAENA CINNABARI BALF. RESIN ETHANOLIC EXTRACT OF SOQATRA ISLAND IN EXPERIMENTAL ANIMALS ANTIHYPERGLYCEMIC AND ANTI-OXIDANT POTENTIAL OF ETHANOL EXTRACT OF VITEX THYRSIFLORA LEAVES ON DIABETIC RATS

scholarly journals Inhibition of human cytomegalovirus immediate-early gene expression by an antisense oligonucleotide complementary to immediate-early RNA.

1996 ◽  
Vol 40 (9) ◽  
pp. 2004-2011 ◽  
Author(s):  
K P Anderson ◽  
M C Fox ◽  
V Brown-Driver ◽  
M J Martin ◽  
R F Azad
Keyword(s):  
Gene Expression ◽  
Cell Culture ◽  
Antiviral Activity ◽  
Protein Expression ◽  
Human Cytomegalovirus ◽  
Host Cells ◽  
Early Gene ◽  
Immediate Early ◽  
Mrna Levels ◽  
Virus Adsorption

ISIS 2922 is a phosphorothioate oligonucleotide that is complementary to human cytomegalovirus (CMV) immediate-early (IE) RNA and that exhibits potent and specific antiviral activity against CMV in cell culture assays. Specific assay systems were developed to separately characterize the antisense and nonantisense components of the antiviral activity mediated by ISIS 2922. In U373 cells transformed with cDNA encoding the CMV IE 55-kDa (IE55) protein, expression was inhibited at nanomolar concentrations comparable to effective concentrations in antiviral assays. The specificity of inhibition was demonstrated by using control oligonucleotides incorporating progressive base changes to destabilize oligonucleotide-RNA base pairing and by showing a lack of inhibition of the CMV IE72 product expressed from the same promoter. Inhibition of IE55 protein expression correlated with a reduction in mRNA levels consistent with an RNase H-mediated termination event. Studies with virus-infected cells demonstrated that antisense and nonantisense mechanisms contribute to the antiviral activity of ISIS 2922. Base complementarity to target RNA was important for optimal activity in antiviral assays, but base changes affecting parameters other than hybridization affinity also influenced antiviral activity. Sequence-independent inhibition of virus adsorption to host cells by phosphorothioate oligonucleotides was also observed at high concentrations. Therefore, at least three different mechanisms may contribute to the antiviral activity of ISIS 2922 in cell culture: antisense-mediated inhibition of target gene expression; nonantisense, sequence-dependent inhibition of virus replication; and sequence-independent inhibition of virus adsorption to host cells.

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.

scholarly journals Resveratrol Inhibits Venezuelan Equine Encephalitis Virus Infection by Interfering with the AKT/GSK Pathway

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 346
Author(s):  
Caitlin W. Lehman ◽  
Kylene Kehn-Hall ◽  
Megha Aggarwal ◽  
Nicole R. Bracci ◽  
Han-Chi Pan ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Fluorescent Protein ◽  
Glycogen Synthase ◽  
Venezuelan Equine Encephalitis Virus ◽  
Encephalitis Virus ◽  
Host Cells ◽  
Dynamics Simulation ◽  
Luciferase Reporter ◽  
Venezuelan Equine Encephalitis ◽  
Equine Encephalitis Virus

The host proteins Protein Kinase B (AKT) and glycogen synthase kinase-3 (GSK-3) are associated with multiple neurodegenerative disorders. They are also important for the replication of Venezuelan equine encephalitis virus (VEEV), thereby making the AKT/GSK-3 pathway an attractive target for developing anti-VEEV therapeutics. Resveratrol, a natural phytochemical, has been shown to substantially inhibit the AKT pathway. Therefore, we attempted to explore whether it exerts any antiviral activity against VEEV. In this study, we utilized green fluorescent protein (GFP)- and luciferase-encoding recombinant VEEV to determine the cytotoxicity and antiviral efficacy via luciferase reporter assays, flow cytometry, and immunofluorescent assays. Our results indicate that resveratrol treatment is capable of inhibiting VEEV replication, resulting in increased viability of Vero and U87MG cells as well as reduced virion production and viral RNA contents within host cells for at least 48 h with a single treatment. Furthermore, the suppression of apoptotic signaling adaptors, caspase-3, caspase-7, and annexin V may also be implicated in resveratrol-mediated antiviral activity. We found that decreased phosphorylation of the AKT/GSK-3 pathway, mediated by resveratrol, can be triggered during the early stages of VEEV infection, suggesting that resveratrol disrupts the viral replication cycle and consequently promotes cell survival. Finally, molecular docking and dynamics simulation studies revealed that resveratrol can directly bind to VEEV glycoproteins, which may interfere with virus attachment and entry. In conclusion, our results suggest that resveratrol exerts inhibitory activity against VEEV infection and upon further modification could be a useful compound to study in neuroprotective research and veterinary sciences.

scholarly journals Flavonol 7-O-Glucoside Herbacitrin Inhibits HIV-1 Replication through Simultaneous Integrase and Reverse Transcriptase Inhibition

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Éva Áy ◽  
Attila Hunyadi ◽  
Mária Mezei ◽  
János Minárovits ◽  
Judit Hohmann
Keyword(s):  
Antiviral Activity ◽  
Reverse Transcriptase ◽  
Cell Cultures ◽  
Core Protein ◽  
Integrase Inhibitor ◽  
Host Cells ◽  
Cytotoxic Activities ◽  
Protein Levels ◽  
Hiv 1 ◽  
Antiretroviral Activity

Here we report the evaluation of the antiretroviral effect of two flavonoid 7-O-glucosides, herbacitrin (1) and gossypitrin (2), together with quercetin (3), a well-studied flavonol. Antiviral activity of the flavonoids was assessed by analyzing HIV-1 p24 core protein levels in the supernatants of HIV-1 infected MT-4 and MT-2 cell cultures. The compounds showed mild to weak cytotoxic activities on the host cells; herbacitrin was the strongest in this regard (CC50=27.8 and 63.64 μM on MT-4 and MT-2 cells, respectively). In nontoxic concentrations, herbacitrin and quercetin reduced HIV-1 replication, whereas gossypitrin was ineffective. Herbacitrin was found to inhibit reverse transcriptase at 21.5 μM, while it was a more potent integrase inhibitor already active at 2.15 μM. Therefore, our observations suggest that herbacitrin exerts antiretroviral activity through simultaneously acting on these two targets of HIV-1 and that integrase inhibition might play a major role in this activity.

scholarly journals Modelling the impact of the macroalgae Asparagopsis taxiformis on rumen microbial fermentation

2020 ◽  
Author(s):  
Rafael Muñoz-Tamayo ◽  
Juana C. Chagas ◽  
Mohammad Ramin ◽  
Sophie J. Krizsan
Keyword(s):  
Methane Production ◽  
Volatile Fatty Acids ◽  
Mean Squared Error ◽  
Microbial Fermentation ◽  
Model Structure ◽  
Red Macroalgae ◽  
Asparagopsis Taxiformis ◽  
The Impact

AbstractBackgroundThe red macroalgae Asparagopsis taxiformis is a potent natural supplement for reducing methane production from cattle. A. taxiformis contains several anti-methanogenic compounds including bromoform that inhibits directly methanogenesis. The positive and adverse effects of A. taxiformis on the rumen microbiota are dose-dependent and operate in a dynamic fashion. It is therefore key to characterize the dynamic response of the rumen microbial fermentation for identifying optimal conditions on the use of A. taxiformis as a dietary supplement for methane mitigation. Accordingly, the objective of this work was to model the effect of A. taxiformis supplementation on the rumen microbial fermentation under in vitro conditions. We adapted a published mathematical model of rumen microbial fermentation to account for A. taxiformis supplementation. We modelled the impact of A. taxiformis on the fermentation and methane production by two mechanisms, namely (i) direct inhibition of the growth rate of methanogenesis by bromoform and (ii) hydrogen control on sugars utilization and on the flux distribution towards volatile fatty acids production. We calibrated our model using a multi-experiment estimation approach that integrated experimental data with six macroalgae supplementation levels from a published in vitro study assessing the dose-response impact of A. taxiformis on rumen fermentation.Resultsour model captured satisfactorily the effect of A. taxiformis on the dynamic profile of rumen microbial fermentation for the six supplementation levels of A. taxiformis with an average determination coefficient of 0.88 and an average coefficient of variation of the root mean squared error of 15.2% for acetate, butyrate, propionate, ammonia and methane.Conclusionsour results indicated the potential of our model as prediction tool for assessing the impact of additives such as seaweeds on the rumen microbial fermentation and methane production in vitro. Additional dynamic data on hydrogen and bromoform are required to validate our model structure and look for model structure improvements. We are working on model extensions to account for in vivo conditions. We expect this model development can be useful to help the design of sustainable nutritional strategies promoting healthy rumen function and low environmental footprint.

scholarly journals Ability of Foot-and-Mouth Disease Virus To Form Plaques in Cell Culture Is Associated with Suppression of Alpha/Beta Interferon

1999 ◽  
Vol 73 (12) ◽  
pp. 9891-9898 ◽  
Author(s):  
Jarasvech Chinsangaram ◽  
Maria E. Piccone ◽  
Marvin J. Grubman
Keyword(s):  
Antiviral Activity ◽  
Disease Virus ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Host Cells ◽  
Wild Type Virus ◽  
Beta Interferon ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Alpha Beta

ABSTRACT A genetic variant of foot-and-mouth disease virus lacking the leader proteinase coding region (A12-LLV2) is attenuated in both cattle and swine and, in contrast to wild-type virus (A12-IC), does not spread from the initial site of infection after aerosol exposure of bovines. We have identified secondary cells from susceptible animals, i.e., bovine, ovine, and porcine animals, in which infection with A12-LLV2, in contrast to A12-IC infection, does not produce plaques; this result indicates that this virus cannot spread from the site of initial infection to neighboring cells. Nevertheless, A12-LLV2 can infect these cells, but cytopathic effects and virus yields are significantly reduced compared to those seen with A12-IC infection. Reverse transcription-PCR analysis demonstrates that both A12-LLV2 and A12-IC induce the production of alpha/beta interferon (IFN-α/β) mRNA in host cells. However, only supernatants from A12-LLV2-infected cells have significant antiviral activity. The antiviral activity in supernatants from A12-LLV2-infected embryonic bovine kidney cells is IFN-α/β specific, as assayed with mouse embryonic fibroblast cells with or without IFN-α/β receptors. The results obtained with cell cultures demonstrate that the ability of A12-IC to form plaques is associated with the suppression of IFN-α/β expression and suggest a role for this host factor in the inability of A12-LLV2 to spread and cause disease in susceptible animals.

scholarly journals Newcastle disease virus may enter cells by caveolae-mediated endocytosis

2007 ◽  
Vol 88 (2) ◽  
pp. 559-569 ◽  
Author(s):  
Celia Cantín ◽  
Javier Holguera ◽  
Laura Ferreira ◽  
Enrique Villar ◽  
Isabel Muñoz-Barroso
Keyword(s):  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Inhibitory Effect ◽  
Endocytic Pathway ◽  
Host Cells ◽  
Virus Concentration ◽  
Double Labelling ◽  
Virus Adsorption ◽  
Labelling Immunofluorescence

The entry into cells of Newcastle disease virus (NDV), a prototype member of the paramyxoviruses, is believed to occur by direct fusion at the plasma membrane through a pH-independent mechanism. In addition, NDV may enter host cells by an endocytic pathway. Treatment of cells with drugs that block caveolae-dependent endocytosis reduced NDV fusion and infectivity, the degree of inhibition being dependent on virus concentration. The inhibitory effect was reduced greatly when drugs were added after virus adsorption. Cells treated with methyl β-cyclodextrin, a drug that sequesters cholesterol from membranes, reduced the extent of fusion, infectivity and virus–cell binding; this indicates that cholesterol plays a role in NDV entry. Double-labelling immunofluorescence assays performed with anti-NDV monoclonal antibodies and antibodies against the early endosome marker EEA1 revealed the localization of the virus in these intracellular structures. Using fluorescence microscopy, it was found that cell–cell fusion was enhanced at low pH. It is concluded that NDV may infect cells through a caveolae-dependent endocytic pathway, suggesting that this pathway could be an alternative route for virus entry into cells.

scholarly journals Antiviral Activity of a Turbot (Scophthalmus maximus) NK-Lysin Peptide by Inhibition of Low-pH Virus-Induced Membrane Fusion

Marine Drugs ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 87 ◽  
Author(s):  
Alberto Falco ◽  
Regla Medina-Gali ◽  
José Poveda ◽  
Melissa Bello-Perez ◽  
Beatriz Novoa ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Viral Infections ◽  
Scophthalmus Maximus ◽  
Low Ph ◽  
Host Cells ◽  
Viral Origin ◽  
Membrane Rupture ◽  
Viral Particles ◽  
Strong Antiviral Activity ◽  
Turbot Scophthalmus Maximus

Global health is under attack by increasingly-frequent pandemics of viral origin. Antimicrobial peptides are a valuable tool to combat pathogenic microorganisms. Previous studies from our group have shown that the membrane-lytic region of turbot (Scophthalmus maximus) NK-lysine short peptide (Nkl71–100) exerts an anti-protozoal activity, probably due to membrane rupture. In addition, NK-lysine protein is highly expressed in zebrafish in response to viral infections. In this work several biophysical methods, such as vesicle aggregation, leakage and fluorescence anisotropy, are employed to investigate the interaction of Nkl71–100 with different glycerophospholipid vesicles. At acidic pH, Nkl71–100 preferably interacts with phosphatidylserine (PS), disrupts PS membranes, and allows the content leakage from vesicles. Furthermore, Nkl71–100 exerts strong antiviral activity against spring viremia of carp virus (SVCV) by inhibiting not only the binding of viral particles to host cells, but also the fusion of virus and cell membranes, which requires a low pH context. Such antiviral activity seems to be related to the important role that PS plays in these steps of the replication cycle of SVCV, a feature that is shared by other families of virus-comprising members with health and veterinary relevance. Consequently, Nkl71–100 is shown as a promising broad-spectrum antiviral candidate.

scholarly journals Doratoxylon apetalum, an Indigenous Medicinal Plant from Mascarene Islands, Is a Potent Inhibitor of Zika and Dengue Virus Infection in Human Cells

2019 ◽  
Vol 20 (10) ◽  
pp. 2382 ◽  
Author(s):  
Juliano G. Haddad ◽  
Andrea Cristine Koishi ◽  
Arnaud Gaudry ◽  
Claudia Nunes Duarte dos Santos ◽  
Wildriss Viranaicken ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Medicinal Plant ◽  
Dengue Virus ◽  
Denv Infection ◽  
Antiviral Drugs ◽  
Human Cells ◽  
Host Cells ◽  
Global Public Health ◽  
Denv Serotypes ◽  
Mascarene Islands

Zika virus (ZIKV) and Dengue virus (DENV) are mosquito-borne viruses of the Flavivirus genus that could cause congenital microcephaly and hemorrhage, respectively, in humans, and thus present a risk to global public health. A preventive vaccine against ZIKV remains unavailable, and no specific antiviral drugs against ZIKV and DENV are licensed. Medicinal plants may be a source of natural antiviral drugs which mostly target viral entry. In this study, we evaluate the antiviral activity of Doratoxylum apetalum, an indigenous medicinal plant from the Mascarene Islands, against ZIKV and DENV infection. Our data indicated that D. apetalum exhibited potent antiviral activity against a contemporary epidemic strain of ZIKV and clinical isolates of four DENV serotypes at non-cytotoxic concentrations in human cells. Time-of-drug-addition assays revealed that D. apetalum extract acts on ZIKV entry by preventing the internalisation of virus particles into the host cells. Our data suggest that D. apetalum-mediated ZIKV inhibition relates to virus particle inactivation. We suggest that D. apetalum could be a promising natural source for the development of potential antivirals against medically important flaviviruses.

scholarly journals Effect on Hantavirus Replication of Resins from Heliotropium Species and Other Selected Compounds

2008 ◽  
Vol 3 (4) ◽  
pp. 1934578X0800300
Author(s):  
René Torres Gaona ◽  
Héctor Galeno Araya ◽  
Brenda Modak Canobra
Keyword(s):  
Antiviral Activity ◽  
Inhibition Assay ◽  
Pure Compounds

The present investigation on Heliotropium species was carried out in an attempt to detect possible replication inhibitors of Hantavirus variety Andes. Using the plaque inhibition assay, we have evaluated a group of compounds and resins isolated from Heliotropium species. The antiviral activity was determined between the concentration range 2.5-40.0 μg/mL. Antiviral activity was detected in all the tested resins, particularly that of H. huascoense, with an EC50 value of 12.5 μg/mL. Of the pure compounds tested, the aromatic geranyl derivative filifolinone was the most active. The EC50 value of this compound, 11.3 μg/mL, was similar to that of the control, ribavirin. However, these substances were not selective, but this screening has served to identify those compounds with most promise.

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