Novel quaternary phosphonium-type cationic polyacrylamide and elucidation of dual-functional antibacterial/antiviral activity

RSC Advances ◽  
2014 ◽  
Vol 4 (87) ◽  
pp. 46887-46895 ◽  
Author(s):  
Yan Xue ◽  
Yuanfeng Pan ◽  
Huining Xiao ◽  
Yi Zhao

A novel quaternary phosphonium-type cationic polyacrylamide, which can kill bacteria by destroying the cell membrane, as well as inactivate adenovirus by blocking the viral entry, is developed.

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1085
Author(s):  
Ichrak Ben-Amor ◽  
Maria Musarra-Pizzo ◽  
Antonella Smeriglio ◽  
Manuela D’Arrigo ◽  
Rosamaria Pennisi ◽  
...  

Owing to the richness of bioactive compounds, Olea europea leaf extracts exhibit a range of health effects. The present research evaluated the antibacterial and antiviral effect of leaf extracts obtained from Olea europea L. var. sativa (OESA) and Olea europea var. sylvestris (OESY) from Tunisia. LC-DAD-ESI-MS analysis allowed the identification of different compounds that contributed to the observed biological properties. Both OESA and OESY were active against Gram-positive bacteria (MIC values between 7.81 and 15.61 μg/mL and between 15.61 and 31.25 μg/mL against Staphylococcus aureus ATCC 6538 for OESY and OESA, respectively). The antiviral activity against the herpes simplex type 1 (HSV-1) was assessed on Vero cells. The results of cell viability indicated that Olea europea leaf extracts were not toxic to cultured Vero cells. The half maximal cytotoxic concentration (CC50) values for OESA and OESY were 0.2 mg/mL and 0.82 mg/mL, respectively. Furthermore, both a plaque reduction assay and viral entry assay were used to demonstrate the antiviral activity. In conclusion, Olea europea leaf extracts demonstrated a bacteriostatic effect, as well as remarkable antiviral activity, which could provide an alternative treatment against resistant strains.


Author(s):  
Gabriella da Silva Mendes ◽  
Angélica Ribeiro Soares ◽  
Fernanda Otaviano Martins ◽  
Maria Carolina Maciel de Albuquerque ◽  
Sonia Soares Costa ◽  
...  

We evaluated the antiviral activity of the marine alga, Ulva fasciata, collected from Rasa beach and Forno beach, Búzios, Rio de Janeiro, Brazil on the replication of human metapneumovirus (HMPV). The algae extracts were prepared using three different methodologies to compare the activity of different groups of chemical composites obtained through these different methodologies. Four out of the six extracts inhibited nearly 100% of viral replication. The results demonstrated that the majority of the extracts (five out of six) possess virucidal activity and therefore have the ability to interact with the extracellular viral particles and prevent the infection. On the other hand, only two extracts (from Forno beach, obtained by maceration and maceration of the decoction) were able to interact with cell receptors, hindering the viral entry. Finally, only the extract of algae collected at Forno beach, obtained by maceration presented intracellular activity. To our knowledge, this is a pioneer study on antiviral activity of marine algae against HMPV. It is also the first on antiviral activity against HMPV ever done in Brazil. The study also shows the effect of different environment factors and different chemical procedures used to obtain the extract on its biological properties.


2014 ◽  
Vol 20 (5) ◽  
pp. 673-680 ◽  
Author(s):  
Phillip C. Delekta ◽  
Avi Raveh ◽  
Martha J. Larsen ◽  
Pamela J. Schultz ◽  
Giselle Tamayo-Castillo ◽  
...  

Alphaviruses are a prominent class of reemergent pathogens due to their globally expanding ranges, potential for lethality, and possible use as bioweapons. The absence of effective treatments for alphaviruses highlights the need for innovative strategies to identify antiviral agents. Primary screens that use noninfectious self-replicating RNAs, termed replicons, have been used to identify potential antiviral compounds for alphaviruses. Only inhibitors of viral genome replication, however, will be identified using replicons, which excludes many other druggable steps in the viral life cycle. To address this limitation, we developed a western equine encephalitis virus pseudoinfectious particle system that reproduces several crucial viral life cycle steps in addition to genome replication. We used this system to screen a library containing ~26,000 extracts derived from marine microbes, and we identified multiple bacterial strains that produce compounds with potential antiviral activity. We subsequently used pseudoinfectious particle and replicon assays in parallel to counterscreen candidate extracts, and followed antiviral activity during biochemical fractionation and purification to differentiate between inhibitors of viral entry and genome replication. This novel process led to the isolation of a known alphavirus entry inhibitor, bafilomycin, thereby validating the approach for the screening and identification of potential antiviral compounds.


2018 ◽  
Vol 93 (1) ◽  
Author(s):  
Robert C. Orchard ◽  
Meagan E. Sullender ◽  
Bria F. Dunlap ◽  
Dale R. Balce ◽  
John G. Doench ◽  
...  

ABSTRACT Noroviruses (NoVs) are a leading cause of gastroenteritis worldwide, yet host factors that restrict NoV replication are not well understood. Here, we use a CRISPR activation genome-wide screening to identify host genes that can inhibit murine norovirus (MNoV) replication in human cells. Our screens identified with high confidence 49 genes that can inhibit MNoV infection when overexpressed. A significant number of these genes are in interferon and immune regulation signaling networks, but surprisingly, the majority of the genes identified are neither associated with innate or adaptive immunity nor associated with any antiviral activity. Confirmatory studies of eight of the genes validate the initial screening data. Mechanistic studies on TRIM7 demonstrated a conserved role of the molecule in mouse and human cells in restricting MNoV in a step of infection after viral entry. Furthermore, we demonstrate that two isoforms of TRIM7 have differential antiviral activity. Taken together, these data provide a resource for understanding norovirus biology and demonstrate a robust methodology for identifying new antiviral molecules. IMPORTANCE Norovirus is one of the leading causes of food-borne illness worldwide. Despite its prevalence, our understanding of norovirus biology is limited due to the difficulty in growing human norovirus in vitro and a lack of an animal model. Murine norovirus (MNoV) is a model norovirus system because MNoV replicates robustly in cell culture and in mice. To identify host genes that can restrict norovirus replication when overexpressed, we performed genome-wide CRISPR activation screens to induce gene overexpression at the native locus through recruitment of transcriptional activators to individual gene promoters. We found 49 genes that could block murine norovirus replication in human cells. Several of these genes are associated with classical immune signaling pathways, while many of the molecules we identified have not been previously associated with antiviral activity. Our data are a resource for those studying noroviruses, and we provide a robust approach to identify novel antiviral genes.


Author(s):  
Mojtaba Bakhtiari ◽  
Kamyar Asadipooya

Abstract: A new coronavirus pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2], has been on the rise. This virus is fatal for broad groups of populations, including elderly, men, and patients with comorbidities among which obesity is a possible risk factor. The pathophysiologic connections between obesity/metainflammation and COVID-19 may be directly related to increasing soluble ACE2 (angiotensin-converting enzyme 2] levels which potentiates the viral entrance into the host cells, or indirectly related to dysregulation of immune system, microvascular injury and hypercoagulability. The SARS-CoV-2 S-glycoprotein interacts mainly with ACE2 or possibly DDP4 receptors to enter into the host cells. The host proteases, especially TMPRSS2 (transmembrane protease serine 2], support the fusion process and virus entry. While membranous ACE2 is considered a port of entry to the cell for SARS-CoV-2, it seems that soluble ACE2 retains its virus binding capability and enhances its entry into the cells. Interestingly, ACE2 on cell membrane may have protective roles by diminishing cytokine storm-related injuries to the organs. Applying medications that can reduce soluble ACE2 levels, antagonizing TMPRSS2 or blocking DDP4 can improve the outcomes of COVID-19. Metformin and statins through immunomodulatory activities, Orlistat by reducing viral replication, and thiazolidinediones by upregulating ACE2 expression have potential beneficial effects against COVID-19. However, the combination of dipeptidyl peptidase-4 (DDP4] inhibitors and spironolactone/eplerenone seems to be more effective by reducing soluble ACE2 level, antagonizing TMPRSS2, maintaining ACE2 on cell membrane and reducing risk of viral entry into the cells.


2019 ◽  
Vol 20 (16) ◽  
pp. 3859 ◽  
Author(s):  
Michael Winkler ◽  
Florian Wrensch ◽  
Pascale Bosch ◽  
Maike Knoth ◽  
Michael Schindler ◽  
...  

The interferon-induced transmembrane proteins 1–3 (IFITM1–3) inhibit host cell entry of several viruses. However, it is incompletely understood how IFITM1–3 exert antiviral activity. Two phenylalanine residues, F75 and F78, within the intramembrane domain 1 (IM1) were previously shown to be required for IFITM3/IFITM3 interactions and for inhibition of viral entry, suggesting that IFITM/IFITM interactions might be pivotal to antiviral activity. Here, we employed a fluorescence resonance energy transfer (FRET) assay to analyze IFITM/IFITM interactions. For assay calibration, we equipped two cytosolic, non-interacting proteins, super yellow fluorescent protein (SYFP) and super cyan fluorescent protein (SCFP), with signals that target proteins to membrane rafts and also analyzed a SCFP-SYFP fusion protein. This strategy allowed us to discriminate background signals resulting from colocalization of proteins at membrane subdomains from signals elicited by protein–protein interactions. Coexpression of IFITM1–3 and IFITM5 fused to fluorescent proteins elicited strong FRET signals, and mutation of F75 and F78 in IFITM3 (mutant IFITM3-FF) abrogated antiviral activity, as expected, but did not alter cellular localization and FRET signals. Moreover, IFITM3-FF co-immunoprecipitated efficiently with wild type (wt) IFITM3, lending further support to the finding that lack of antiviral activity of IFITM3-FF was not due to altered membrane targeting or abrogated IFITM3-IFITM3 interactions. Collectively, we report an assay that allows quantifying IFITM/IFITM interactions. Moreover, we confirm residues F75 and F78 as critical for antiviral activity but also show that these residues are dispensable for IFITM3 membrane localization and IFITM3/IFITM3 interactions.


2002 ◽  
Vol 13 (5) ◽  
pp. 283-288 ◽  
Author(s):  
T Kawahata ◽  
T Otake ◽  
H Mori ◽  
Y Kojima ◽  
I Oishi ◽  
...  

Pf-gp6, a 6 kDa anti-degranulation glycoprotein purified from the extract of Perilla frutescens, was examined for its antiviral activity against HIV-1 and HIV-2 in vitro. HIV-1-induced cytopathic effect and proviral DNA synthesis were inhibited in the presence of Pf-gp6. The 50% inhibitory concentrations of Pf-gp6 for various HIV-1 strains, including clinical isolates and CCR5-using (R5) HIV-1, ranged between 1.3 and 71.0 μg/ml, depending on the combination of viral strain and host cell. Furthermore, Pf-gp6 did not directly inactivate infectious viral particles. A time-of-addition experiment revealed that Pf-gp6 lost its activity before zidovudine but after the CXCR-4 antagonist AMD3100 during the early stage of viral infection. Although the pinpoint target of Pf-gp6 remains to be elucidated, it may interfere with a step between viral entry and reverse transcription.


2014 ◽  
Vol 58 (6) ◽  
pp. 3451-3460 ◽  
Author(s):  
Lidia Mingorance ◽  
Martina Friesland ◽  
Mairene Coto-Llerena ◽  
Sofía Pérez-del-Pulgar ◽  
Loreto Boix ◽  
...  

ABSTRACTHepatitis C virus (HCV) infection is a major biomedical problem worldwide as it causes severe liver disease in millions of humans around the world. Despite the recent approval of specific drugs targeting HCV replication to be used in combination with alpha interferon (IFN-α) and ribavirin, there is still an urgent need for pangenotypic, interferon-free therapies to fight this genetically diverse group of viruses. In this study, we used an unbiased screening cell culture assay to interrogate a chemical library of compounds approved for clinical use in humans. This system enables identifying nontoxic antiviral compounds targeting every aspect of the viral life cycle, be the target viral or cellular. The aim of this study was to identify drugs approved for other therapeutic applications in humans that could be effective components of combination therapies against HCV. As a result of this analysis, we identified 12 compounds with antiviral activity in cell culture, some of which had previously been identified as HCV inhibitors with antiviral activity in cell culture and had been shown to be effective in patients. We selected two novel HCV antivirals, hydroxyzine and benztropine, to characterize them by determining their specificity and genotype spectrum as well as by defining the step of the replication cycle targeted by these compounds. We found that both compounds effectively inhibited viral entry at a postbinding step of genotypes 1, 2, 3, and 4 without affecting entry of other viruses.


2021 ◽  
Author(s):  
Robert J Stott ◽  
Toshana L Foster

In the absence of effective vaccines and treatments, annual outbreaks of severe human haemorrhagic fever caused by arenaviruses, such as Lassa virus, continue to pose a significant human health threat. Understanding the balance of cellular factors that inhibit or promote arenavirus infection may have important implications for the development of effective antiviral strategies. Here, we identified the cell-intrinsic zinc transmembrane metalloprotease, ZMPSTE24, as a restriction factor against arenaviruses. Notably, CRISPR-Cas9-mediated knockout of ZMPSTE24 in human alveolar epithelial A549 cells increased arenavirus glycoprotein-mediated viral entry in pseudoparticle assays and live virus infection models. As a barrier to viral entry and replication, ZMPSTE24 may act as a downstream effector of interferon-induced transmembrane protein (IFITM) antiviral function; though through a yet poorly understood mechanism. Overexpression of IFITM1, IFITM2 and IFITM3 proteins did not restrict the entry of pseudoparticles carrying arenavirus envelope glycoproteins and live virus infection, yet depletion of IFITM protein expression enhanced virus entry and replication. Furthermore, gain-of-function studies revealed that IFITMs augment the antiviral activity of ZMPSTE24 against arenaviruses, suggesting a cooperative effect of viral restriction. We show that ZMPSTE24 and IFITMs affect the kinetics of cellular endocytosis, suggesting that perturbation of membrane structure and stability is likely the mechanism of ZMPSTE24-mediated restriction and cooperative ZMPSTE24-IFITM antiviral activity. Collectively, our findings define the role of ZMPSTE24 host restriction activity in the early stages of arenavirus infection. Moreover, we provide insight into the importance of cellular membrane integrity for productive fusion of arenaviruses and highlight a novel avenue for therapeutic development.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Adita Ayu Permanasari ◽  
Chie Aoki-Utsubo ◽  
Tutik Sri Wahyuni ◽  
Lidya Tumewu ◽  
Myrna Adianti ◽  
...  

Abstract Background Current therapy of chronic hepatitis C virus (HCV) with direct-acting antivirals (DAAs) has dramatically improved the sustained virologic response (SVR) of affected patients; however, treatment with DAAs remains expensive, and drug-resistant HCV variants remain a threat. As a result, there is still a need to continue to develop affordable and effective drugs for the treatment of HCV. Previously, we have demonstrated that a crude extract from Artocarpus heterophyllus leaves is a potential anti-HCV candidate. In this study, we have further purified this crude extract, examined which sub-fraction possesses the highest antiviral activity, and then explored its efficacy at different HCV life cycle stages. We also assessed synergistic antiviral effects between the A. heterophyllus extract and commercially available anti-HCV drugs. Methods We used vacuum liquid chromatography (VLC) and high-performance liquid chromatography (HPLC) to fractionate a dichloromethane extract of A. heterophyllus leaves. We then examined the anti-HCV activity of the fractions using HCV genotype 2a, JFH1a; the antiviral mode of action was determined by exploring adding the treatments at different times. We examined the antiviral effects on the viral entry stage through a virucidal activity test, viral adsorption examination, and pretreatment of cells with the drug. The effects on the post-viral entry stage were determined by the levels of HCV protein expression and HCV RNA expression in infected cells. Results Through activity guided purification, we identified the sub-fraction FR3T3 as possessing the most robust anti-HCV activity with an IC50 value of 4.7 ± 1.0 μg/mL. Mode-of-action analysis revealed that FR3T3 inhibited post-viral entry stages such as HCV NS3 protein expression and HCV RNA replication with marginal effects on the viral entry stage. Thin-layer Chromatography (TLC) indicated that FR3T3 contained terpenoids and chlorophyll-related compounds. We also found a synergistic antiviral activity when the DCM extract of A. heterohyllus was used in combination therapy with commercial anti-HCV drugs; Ribavirin, Simeprevir, Cyclosporin A. Conclusions The extract of A. heterophyllus and its sub-fraction, FR3T3, presented here have anti-HCV activities and could be candidate drugs for add-on-therapy for treatment of chronic HCV infections.


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