scholarly journals Antiviral activity of silymarin and baicalein against dengue virus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhao Xuan Low ◽  
Brian Ming OuYong ◽  
Pouya Hassandarvish ◽  
Chit Laa Poh ◽  
Babu Ramanathan
Keyword(s):  
Antiviral Activity ◽  
Dengue Virus ◽  
Viral Entry ◽  
Dengue Infection ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Vero Cells ◽  
Viral Envelope ◽  
E Protein

AbstractDengue is an arthropod-borne viral disease that has become endemic and a global threat in many countries with no effective antiviral drug available currently. This study showed that flavonoids: silymarin and baicalein could inhibit the dengue virus in vitro and were well tolerated in Vero cells with a half-maximum cytotoxic concentration (CC50) of 749.70 µg/mL and 271.03 µg/mL, respectively. Silymarin and baicalein exerted virucidal effects against DENV-3, with a selective index (SI) of 10.87 and 21.34, respectively. Baicalein showed a better inhibition of intracellular DENV-3 progeny with a SI of 7.82 compared to silymarin. Baicalein effectively blocked DENV-3 attachment (95.59%) to the Vero cells, while silymarin prevented the viral entry (72.46%) into the cells, thus reducing viral infectivity. Both flavonoids showed promising antiviral activity against all four dengue serotypes. The in silico molecular docking showed that silymarin could bind to the viral envelope (E) protein with a binding affinity of − 8.5 kcal/mol and form hydrogen bonds with the amino acids GLN120, TRP229, ASN89, and THR223 of the E protein. Overall, this study showed that silymarin and baicalein exhibited potential anti-DENV activity and could serve as promising antiviral agents for further development against dengue infection.

scholarly journals In Vitro Reconstitution Reveals Key Intermediate States of Trimer Formation by the Dengue Virus Membrane Fusion Protein

2010 ◽  
Vol 84 (11) ◽  
pp. 5730-5740 ◽  
Author(s):  
Maofu Liao ◽  
Claudia Sánchez-San Martín ◽  
Aihua Zheng ◽  
Margaret Kielian
Keyword(s):  
Dengue Virus ◽  
Membrane Fusion ◽  
Transmembrane Protein ◽  
Fusion Reaction ◽  
Low Ph ◽  
Viral Envelope ◽  
Interaction Sites ◽  
E Protein ◽  
Hairpin Formation

ABSTRACT The flavivirus dengue virus (DV) infects cells through a low-pH-triggered membrane fusion reaction mediated by the viral envelope protein E. E is an elongated transmembrane protein with three domains and is organized as a homodimer on the mature virus particle. During fusion, the E protein homodimer dissociates, inserts the hydrophobic fusion loop into target membranes, and refolds into a trimeric hairpin in which domain III (DIII) packs against the central trimer. It is clear that E refolding drives membrane fusion, but the steps in hairpin formation and their pH requirements are unclear. Here, we have used truncated forms of the DV E protein to reconstitute trimerization in vitro. Protein constructs containing domains I and II (DI/II) were monomeric and interacted with membranes to form core trimers. DI/II-membrane interaction and trimerization occurred efficiently at both neutral and low pH. The DI/II core trimer was relatively unstable and could be stabilized by binding exogenous DIII or by the formation of mixed trimers containing DI/II plus E protein with all three domains. The mixed trimer had unoccupied DIII interaction sites that could specifically bind exogenous DIII at either low or neutral pH. Truncated DV E proteins thus reconstitute hairpin formation and define properties of key domain interactions during DV fusion.

scholarly journals In vitro Assessment of Antiviral Effect of Natural Compounds on Porcine Epidemic Diarrhea Coronavirus

2021 ◽  
Vol 8 ◽  
Author(s):  
Manuel Gómez-García ◽  
Héctor Puente ◽  
Héctor Argüello ◽  
Óscar Mencía-Ares ◽  
Pedro Rubio ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Formic Acid ◽  
Antiviral Agents ◽  
Antiviral Effect ◽  
Vero Cells ◽  
Optical Microscope ◽  
Dependent Manner ◽  
Diarrhea Virus ◽  
Porcine Epidemic Diarrhea

Organic acid and essential oils (EOs), well-known antimicrobials, could also possess antiviral activity, a characteristic which has not been completely addressed up to now. In this study, the effect of two organic acids (formic acid and sodium salt of coconut fatty acid distillates) and two single EO compounds (thymol and cinnamaldehye) was evaluated against porcine epidemic diarrhea virus (PEDV). The concentration used for each compound was established by cytotoxicity assays in Vero cells. The antiviral activity was then evaluated at three multiplicities of infection (MOIs) through visual cytopathic effect (CPE) evaluation and an alamarBlue assay as well as real-time reverse-transcription PCR (RT-qPCR) and viral titration of cell supernatants. Formic acid at at a dose of 1,200 ppm was the only compound which showed antiviral activity, with a weak reduction of CPE caused by PEDV. Through the alamarBlue fluorescence assay, we showed a significant anti-CPE effect of formic acid which could not be observed by using an inverted optical microscope. RT-qPCR and infectivity analysis also showed that formic acid significantly reduced viral RNA and viral titers in a PEDV MOI-dependent manner. Our results suggest that the antiviral activity of formic acid could be associated to its inhibitory effect on viral replication. Further studies are required to explore the anti-PEDV activity of formic acid under field conditions alone or together with other antiviral agents.

scholarly journals Broad-spectrum virucidal activity of bacterial secreted lipases against flaviviruses, SARS-CoV-2 and other enveloped viruses

2020 ◽  
Author(s):  
Xi Yu ◽  
Liming Zhang ◽  
Liangqin Tong ◽  
Nana Zhang ◽  
Han Wang ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Lipase Activity ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Viral Envelope ◽  
Global Public Health ◽  
Virucidal Activity ◽  
Extracellular Milieu

AbstractViruses are the major aetiological agents of acute and chronic severe human diseases that place a tremendous burden on global public health and economy; however, for most viruses, effective prophylactics and therapeutics are lacking, in particular, broad-spectrum antiviral agents. Herein, we identified 2 secreted bacterial lipases from a Chromobacterium bacterium, named Chromobacterium antiviral effector-1 (CbAE-1) and CbAE-2, with a broad-spectrum virucidal activity against dengue virus (DENV), Zika virus (ZIKV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human immunodeficiency virus (HIV) and herpes simplex virus (HSV). The CbAEs potently blocked viral infection in the extracellular milieu through their lipase activity. Mechanistic studies showed that this lipase activity directly disrupted the viral envelope structure, thus inactivating infectivity. A mutation of CbAE-1 in its lipase motif fully abrogated the virucidal ability. Furthermore, CbAE-2 presented low toxicity in vivo and in vitro, highlighting its potential as a broad-spectrum antiviral drug.

scholarly journals Evaluation of Antiviral Activities of Curcumin Derivatives against HSV-1 in Vero Cell Line

2010 ◽  
Vol 5 (12) ◽  
pp. 1934578X1000501 ◽  
Author(s):  
Keivan Zandi ◽  
Elissa Ramedani ◽  
Khosro Mohammadi ◽  
Saeed Tajbakhsh ◽  
Iman Deilami ◽  
...  
Keyword(s):  
Cell Culture ◽  
Antiviral Activity ◽  
Vero Cell ◽  
Cell Line ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
In Vitro Study ◽  
Vero Cell Line ◽  
Hsv 1

Antiviral drug resistance is one of the most common problems in medicine, and, therefore, finding new antiviral agents, especially from natural resources, seems to be necessary. This study was designed to assay the antiviral activity of curcumin and its new derivatives like gallium-curcumin and Cu-curcumin on replication of HSV-1 in cell culture. The research was performed as an in vitro study in which the antiviral activity of different concentrations of three substances including curcumin, Gallium-curcumin and Cu-curcumin were tested on HSV-1. The cytotoxicity of the tested compounds was also evaluated on the Vero cell line. The CC50 values for curcumin, gallium-curcumin and Cu-curcumin were 484.2 μg/mL, 255.8 μg/mL and 326.6 μg/mL, respectively, and the respective IC50 values 33.0 μg/mL, 13.9 μg/mL and 23.1 μg/mL. The calculated SI values were 14.6, 18.4 and 14.1, respectively. The results showed that curcumin and its new derivatives have remarkable antiviral effects on HSV-1 in cell culture.

scholarly journals Chloroquine Inhibits Dengue Virus Type 2 Replication in Vero Cells but Not in C6/36 Cells

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Kleber Juvenal Silva Farias ◽  
Paula Renata Lima Machado ◽  
Benedito Antônio Lopes da Fonseca
Keyword(s):  
Dengue Virus ◽  
Virus Type ◽  
Mammalian Cells ◽  
Plaque Assay ◽  
Antiviral Drug ◽  
Vero Cells ◽  
Significant Difference ◽  
Dengue Virus Type 2

Dengue viruses are the most important arthropod-borne viruses in terms of morbidity and mortality in the world. Since there is no dengue vaccine available for human use, we have set out to investigate the use of chloroquine as an antiviral drug against dengue. Chloroquine, an amine acidotropic drug known to affect intracellular exocytic pathways by increasing endosomal pH, was used in the in vitro treatment of Vero and C6/36 cells infected with dengue virus type 2 (DENV-2). Real-time RT-PCR and plaque assays were used to quantify the DENV-2 load in infected Vero and C6/36 cells after chloroquine treatment. Our results showed that a dose of 50 μg/ml of chloroquine was not toxic to the cells and induced a statistically significant inhibition of virus production in infected Vero cells when compared to untreated cells. In C6/36 cells, chloroquine does not induce a statistically significant difference in viral replication when compared to untreated cells, showing that this virus uses an unlikely pathway of penetration in these cells, and results were also confirmed by the plaque assay (PFU). These data suggest that the inhibition of virus infection induced by chloroquine is due to interference with acidic vesicles in mammalian cells.

scholarly journals Synthesis and Antiviral Activity of Camphene Derivatives against Different Types of Viruses

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2235
Author(s):  
Anastasiya S. Sokolova ◽  
Valentina P. Putilova ◽  
Olga I. Yarovaya ◽  
Anastasiya V. Zybkina ◽  
Ekaterina D. Mordvinova ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Antiviral Activity ◽  
Rational Design ◽  
Ebola Virus ◽  
Viral Infections ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Surface Proteins ◽  
Hantaan Virus

To date, the ‘one bug-one drug’ approach to antiviral drug development cannot effectively respond to the constant threat posed by an increasing diversity of viruses causing outbreaks of viral infections that turn out to be pathogenic for humans. Evidently, there is an urgent need for new strategies to develop efficient antiviral agents with broad-spectrum activities. In this paper, we identified camphene derivatives that showed broad antiviral activities in vitro against a panel of enveloped pathogenic viruses, including influenza virus A/PR/8/34 (H1N1), Ebola virus (EBOV), and the Hantaan virus. The lead-compound 2a, with pyrrolidine cycle in its structure, displayed antiviral activity against influenza virus (IC50 = 45.3 µM), Ebola pseudotype viruses (IC50 = 0.12 µM), and authentic EBOV (IC50 = 18.3 µM), as well as against pseudoviruses with Hantaan virus Gn-Gc glycoprotein (IC50 = 9.1 µM). The results of antiviral activity studies using pseudotype viruses and molecular modeling suggest that surface proteins of the viruses required for the fusion process between viral and cellular membranes are the likely target of compound 2a. The key structural fragments responsible for efficient binding are the bicyclic natural framework and the nitrogen atom. These data encourage us to conduct further investigations using bicyclic monoterpenoids as a scaffold for the rational design of membrane-fusion targeting inhibitors.

scholarly journals Bisbenzylisoquinoline Alkaloids of Cissampelos Sympodialis With in Vitro Antiviral Activity Against Zika Virus

2021 ◽  
Vol 12 ◽  
Author(s):  
Poliena Gomes da Silva ◽  
Aventino H. Fonseca ◽  
Malu P. Ribeiro ◽  
Taizia D. Silva ◽  
Cristiane F. F. Grael ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Zika Virus ◽  
High Performance ◽  
Antiviral Agents ◽  
Virus Titer ◽  
Vero Cells ◽  
Positive Control ◽  
Bisbenzylisoquinoline Alkaloids ◽  
Bioassay Guided Fractionation

In search of new antiviral compounds against Zika virus we conducted a bioassay-guided fractionation of bisbenzyilisoquinoline alkaloids isolated from Cissampelos sympodialis (Menispermaceae), a medicinal plant species endemic to Brazil. Six subfractions were obtained from a tertiary alkaloidal fraction of the rhizomes (TAFrz) using preparative high-performance liquid chromatography. All the subfractions were tested against Zika virus-infected Vero cells as the cellular model to evaluate cytotoxicity and antiviral effective concentrations. The results showed that three of the six TAFrz subfractions tested were active. The most active ones were the subfraction 6 (that consisted of the alkaloids methylwarifteine and warifteine present as a mixture at a ratio of 8.8:1.2 respectively) and the subfraction 5, that was later identified as warifteine, the major tertiary alkaloid of this species. Warifteine was able to significantly reduce virus titer in Zika virus-infected Vero cells with an IC50 of 2.2 μg/ml and this effect was selective (selectivity index, SI = 68.3). Subfraction 6 had an IC50 = 3.5 μg/ml and was more cytotoxic than pure warifteine, with SI = 6.14. Fraction 5 and fraction 6 were more potent in decreasing the viral titer of Zika virus-infected Vero cells than 6-methylmercaptopurine riboside (IC50 = 24.5 μg/ml and SI = 11.9), a mercaptopurine riboside with ZIKV antiviral activity used as a positive control. Our data demonstrate that alkaloids of the bisbenzylisoquinoline type may be explored as new antiviral agents or as an useful pharmacophore for investigating ZIKV antiviral activity.

scholarly journals In Vitro and in Vivo Antiviral Activity of Mizoribine Against Foot-And-Mouth Disease Virus

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1723 ◽  
Author(s):  
Shi-Fang Li ◽  
Mei-Jiao Gong ◽  
Yue-Feng Sun ◽  
Jun-Jun Shao ◽  
Yong-Guang Zhang ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Early Stage ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Mouth Disease Virus ◽  
Foot And Mouth

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals, which has significant economic consequences in affected countries. As the currently available vaccines against FMD provide no protection until 4–7 days post-vaccination, the only alternative method to control the spread of FMD virus (FMDV) during outbreaks is the application of antiviral agents. Hence, it is important to identify effective antiviral agents against FMDV infection. In this study, we found that mizoribine has potent antiviral activity against FMDV replication in IBRS-2 cells. A time-of-drug-addition assay demonstrated that mizoribine functions at the early stage of replication. Moreover, mizoribine also showed antiviral effect on FMDV in vivo. In summary, these results revealed that mizoribine could be a potential antiviral drug against FMDV.

scholarly journals In Vitro Evaluation of the Antiviral Activity of Methylene Blue Alone or in Combination against SARS-CoV-2

2021 ◽  
Vol 10 (14) ◽  
pp. 3007
Author(s):  
Mathieu Gendrot ◽  
Priscilla Jardot ◽  
Océane Delandre ◽  
Manon Boxberger ◽  
Julien Andreani ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Antiviral Activity ◽  
Viral Entry ◽  
Low Cost ◽  
Antiviral Drug ◽  
Effective Concentration ◽  
Rt Pcr ◽  
Post Entry ◽  
Median Effective Concentration

A new severe acute respiratory syndrome coronavirus (SARS-CoV-2) causing coronavirus diseases 2019 (COVID-19), which emerged in Wuhan, China in December 2019, has spread worldwide. Currently, very few treatments are officially recommended against SARS-CoV-2. Identifying effective, low-cost antiviral drugs with limited side effects that are affordable immediately is urgently needed. Methylene blue, a synthesized thiazine dye, may be a potential antiviral drug. Antiviral activity of methylene blue used alone or in combination with several antimalarial drugs or remdesivir was assessed against infected Vero E6 cells infected with two clinically isolated SARS-CoV-2 strains (IHUMI-3 and IHUMI-6). Effects both on viral entry in the cell and on post-entry were also investigated. After 48 h post-infection, the viral replication was estimated by RT-PCR. The median effective concentration (EC50) and 90% effective concentration (EC90) of methylene blue against IHUMI-3 were 0.41 ± 0.34 µM and 1.85 ± 1.41 µM, respectively; 1.06 ± 0.46 µM and 5.68 ± 1.83 µM against IHUMI-6. Methylene blue interacted at both entry and post-entry stages of SARS-CoV-2 infection in Vero E6 cells as retrieved for hydroxychloroquine. The effects of methylene blue were additive with those of quinine, mefloquine and pyronaridine. The combinations of methylene blue with chloroquine, hydroxychloroquine, desethylamodiaquine, piperaquine, lumefantrine, ferroquine, dihydroartemisinin and remdesivir were antagonist. These results support the potential interest of methylene blue to treat COVID-19.

scholarly journals Inhibition of Enterovirus 71 by Picochlorum sp. 122 via AKT and ATM/ATR Signaling Pathways

2021 ◽  
Author(s):  
Min Guo ◽  
Ruilin Zheng ◽  
Hua-lian Wu ◽  
Danyang Chen ◽  
Jingyao Su ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Signaling Pathways ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Vero Cells ◽  
Host Cells ◽  
Global Public Health ◽  
Protein Levels

Abstract Enterovirus 71 (EV71) pose a critical threat in global public health and may lead to severe and even lethal cases of hand-foot-and-mouth disease (HFMD). No effective antiviral agents are available to the masses for treatment of HFMD caused by EV71. Polysaccharide provides a good clinical application for antivirus. Polysaccharides extracted from Picochlorum sp. 122 (PPE) is a kind of seaweed Polysaccharides, the reports on its antiviral activity are limited. In this study, the antiviral activity was verified in Vero cells. Briefly, PPE has been demonstrated to restrain EV71 infection through MTT assay and cellular cytopathic effect. In addition, the decrease of the nucleic acid and protein levels of VP1 indicated PPE effectively inhibited the proliferation of EV71 in Vero cells. Furthermore, the annexinV-affinity assay suggested that PPE protected host cells from apoptosis. The mechanistic investigations revealed that PPE restrained EV71-induced host-cells apoptosis by AKT and ATM/ATR signaling pathways. In conclusion, these results demonstrate PPE is a hopeful antiviral drug for the infection of EV71.

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