scholarly journals The SARS-CoV-2-Inactivating Activity of Hydroxytyrosol-Rich Aqueous Olive Pulp Extract (HIDROX®) and Its Use as a Virucidal Cream for Topical Application

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 232
Author(s):  
Yohei Takeda ◽  
Dulamjav Jamsransuren ◽  
Sachiko Matsuda ◽  
Roberto Crea ◽  
Haruko Ogawa
Keyword(s):  
Molecular Weight ◽  
Severe Acute Respiratory Syndrome ◽  
Viral Genome ◽  
Structural Changes ◽  
Control Measures ◽  
Spike Protein ◽  
Virucidal Activity ◽  
Olive Pulp ◽  
Hand Cream

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally. Although measures to control SARS-CoV-2, namely, vaccination, medication, and chemical disinfectants are being investigated, there is an increase in the demand for auxiliary antiviral approaches using natural compounds. Here we have focused on hydroxytyrosol (HT)-rich aqueous olive pulp extract (HIDROX®) and evaluated its SARS-CoV-2-inactivating activity in vitro. We showed that the HIDROX solution exhibits time- and concentration-dependent SARS-CoV-2-inactivating activities, and that HIDROX has more potent virucidal activity than pure HT. The evaluation of the mechanism of action suggested that both HIDROX and HT induced structural changes in SARS-CoV-2, which changed the molecular weight of the spike proteins. Even though the spike protein is highly glycosylated, this change was induced regardless of the glycosylation status. In addition, HIDROX or HT treatment disrupted the viral genome. Moreover, the HIDROX-containing cream applied on film showed time- and concentration-dependent SARS-CoV-2-inactivating activities. Thus, the HIDROX-containing cream can be applied topically as an antiviral hand cream. Our findings suggest that HIDROX contributes to improving SARS-CoV-2 control measures.

scholarly journals SARS-CoV-2 Inhibition by Sulfonated Compounds

2020 ◽  
Vol 8 (12) ◽  
pp. 1894
Author(s):  
Matteo Gasbarri ◽  
Philip V’kovski ◽  
Giulia Torriani ◽  
Volker Thiel ◽  
Francesco Stellacci ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Vesicular Stomatitis Virus ◽  
Inhibitory Activity ◽  
Spike Protein ◽  
Converting Enzyme ◽  
Virucidal Activity ◽  
Angiotensin Converting Enzyme 2 ◽  
Vesicular Stomatitis ◽  
Heparan Sulfates

Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) depends on angiotensin converting enzyme 2 (ACE2) for cellular entry, but it might also rely on attachment receptors such as heparan sulfates. Several groups have recently demonstrated an affinity of the SARS-CoV2 spike protein for heparan sulfates and a reduced binding to cells in the presence of heparin or heparinase treatment. Here, we investigated the inhibitory activity of several sulfated and sulfonated molecules, which prevent interaction with heparan sulfates, against vesicular stomatitis virus (VSV)-pseudotyped-SARS-CoV-2 and the authentic SARS-CoV-2. Sulfonated cyclodextrins and nanoparticles that have recently shown broad-spectrum non-toxic virucidal activity against many heparan sulfates binding viruses showed inhibitory activity in the micromolar and nanomolar ranges, respectively. In stark contrast with the mechanisms that these compounds present for these other viruses, the inhibition against SARS-CoV-2 was found to be simply reversible.

scholarly journals Identification of Common Deletions in the Spike Protein of Severe Acute Respiratory Syndrome Coronavirus 2

2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Zhe Liu ◽  
Huanying Zheng ◽  
Huifang Lin ◽  
Mingyue Li ◽  
Runyu Yuan ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Virus Replication ◽  
Receptor Binding ◽  
Cleavage Site ◽  
Spike Protein ◽  
Clinical Samples ◽  
Receptor Binding Domain ◽  
Flanking Sequence

ABSTRACT Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus first identified in December 2019. Notable features that make SARS-CoV-2 distinct from most other previously identified betacoronaviruses include a receptor binding domain and a unique insertion of 12 nucleotides or 4 amino acids (PRRA) at the S1/S2 boundary. In this study, we identified two deletion variants of SARS-CoV-2 that either directly affect the polybasic cleavage site itself (NSPRRAR) or a flanking sequence (QTQTN). These deletions were verified by multiple sequencing methods. In vitro results showed that the deletion of NSPRRAR likely does not affect virus replication in Vero and Vero-E6 cells; however, the deletion of QTQTN may restrict late-phase viral replication. The deletion of QTQTN was detected in 3 of 68 clinical samples and 12 of 24 in vitro-isolated viruses, while the deletion of NSPRRAR was identified in 3 in vitro-isolated viruses. Our data indicate that (i) there may be distinct selection pressures on SARS-CoV-2 replication or infection in vitro and in vivo; (ii) an efficient mechanism for deleting this region from the viral genome may exist, given that the deletion variant is commonly detected after two rounds of cell passage; and (iii) the PRRA insertion, which is unique to SARS-CoV-2, is not fixed during virus replication in vitro. These findings provide information to aid further investigation of SARS-CoV-2 infection mechanisms and a better understanding of the NSPRRAR deletion variant observed here. IMPORTANCE The spike protein determines the infectivity and host range of coronaviruses. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has two unique features in its spike protein, the receptor binding domain and an insertion of 12 nucleotides at the S1/S2 boundary resulting in a furin-like cleavage site. Here, we identified two deletion variants of SARS-CoV-2 that either directly affect the furin-like cleavage site itself (NSPRRAR) or a flanking sequence (QTQTN), and we investigated these deletions in cell isolates and clinical samples. The absence of the polybasic cleavage site in SARS-CoV-2 did not affect virus replication in Vero or Vero-E6 cells. Our data indicate the PRRAR sequence and the flanking QTQTN sequence are not fixed in vitro; thus, there appears to be distinct selection pressures on SARS-CoV-2 sequences in vitro and in vivo. Further investigation of the mechanism of generating these deletion variants and their infectivity in different animal models would improve our understanding of the origin and evolution of this virus.

scholarly journals SARS-CoV-2 spike protein S1 induces fibrin(ogen) resistant to fibrinolysis: Implications for microclot formation in COVID-19

2021 ◽  
Author(s):  
Lize M Grobbelaar ◽  
Chantelle Venter ◽  
Mare Vlok ◽  
Malebogo Ngoepe ◽  
Gert J Laubscher ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Blood Flow ◽  
Severe Acute Respiratory Syndrome ◽  
Fluorescence Microscopy ◽  
Clinical Relevance ◽  
Structural Changes ◽  
Spike Protein ◽  
Plasma Samples ◽  
Electron And Fluorescence Microscopy ◽  
Scanning Electron

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) -induced infection, the cause of coronavirus disease 2019 (COVID-19), is characterized by unprecedented clinical pathologies. One of the most important pathologies, is hypercoagulation and microclots in the lungs of patients. Here we study the effect of isolated SARS-CoV-2 spike protein S1 subunit as potential inflammagen sui generis. Using scanning electron and fluorescence microscopy as well as mass spectrometry, we investigate the potential of this inflammagen to interact with platelets and fibrin(ogen) directly to cause blood hypercoagulation.  Using platelet poor plasma (PPP), we show that spike protein may interfere with blood flow.  Mass spectrometry also showed that when spike protein S1 is added to healthy PPP, it results in structural changes to β and γ fibrin(ogen), complement 3, and prothrombin. These proteins were substantially resistant to trypsinization, in the presence of spike protein S1. Here we suggest that, in part, the presence of spike protein in circulation may contribute to the hypercoagulation in COVID-19 positive patients and may cause substantial impairment of fibrinolysis. Such lytic impairment may result in the persistent large microclots we have noted here and previously in plasma samples of COVID-19 patients. This observation may have important clinical relevance in the treatment of hypercoagulability in COVID-19 patients.

scholarly journals Severe Acute Respiratory Syndrome Coronavirus-2 Inactivation Activity of the Polyphenol-Rich Tea Leaf Extract with Concentrated Theaflavins and Other Virucidal Catechins

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4803
Author(s):  
Yohei Takeda ◽  
Kyohei Tamura ◽  
Dulamjav Jamsransuren ◽  
Sachiko Matsuda ◽  
Haruko Ogawa
Keyword(s):  
Cell Culture ◽  
Severe Acute Respiratory Syndrome ◽  
Real Time ◽  
Western Blotting ◽  
Leaf Extract ◽  
Culture Media ◽  
Control Measures ◽  
Virucidal Activity ◽  
Rt Pcr ◽  
Tea Leaf

Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is producing a large number of infections and deaths globally, the development of supportive and auxiliary treatments is attracting increasing attention. Here, we evaluated SARS-CoV-2-inactivation activity of the polyphenol-rich tea leaf extract TY-1 containing concentrated theaflavins and other virucidal catechins. The TY-1 was mixed with SARS-CoV-2 solution, and its virucidal activity was evaluated. To evaluate the inhibition activity of TY-1 in SARS-CoV-2 infection, TY-1 was co-added with SARS-CoV-2 into cell culture media. After 1 h of incubation, the cell culture medium was replaced, and the cells were further incubated in the absence of TY-1. The viral titers were then evaluated. To evaluate the impacts of TY-1 on viral proteins and genome, TY-1-treated SARS-CoV-2 structural proteins and viral RNA were analyzed using western blotting and real-time RT-PCR, respectively. TY-1 showed time- and concentration-dependent virucidal activity. TY-1 inhibited SARS-CoV-2 infection of cells. The results of western blotting and real-time RT-PCR suggested that TY-1 induced structural change in the S2 subunit of the S protein and viral genome destruction, respectively. Our findings provided basic insights in vitro into the possible value of TY-1 as a virucidal agent, which could enhance the current SARS-CoV-2 control measures.

In Vitro Efficacy of “Essential Iodine Drops” Against Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2)

2020 ◽  
Author(s):  
Köntös Zoltán
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Room Temperature ◽  
Cytopathic Effect ◽  
Virucidal Activity ◽  
Virus Stock ◽  
Infectious Dose ◽  
Strain Virus ◽  
Respiratory Droplets ◽  
Elemental Iodine

AbstractBackgroundAerosolization of respiratory droplets is considered the main route of coronavirus disease 2019 (COVID-19). Therefore, reducing the viral load of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) shed via respiratory droplets is potentially an ideal strategy to prevent the spread of the pandemic. The in vitro virucidal activity of intranasal Povidone-Iodine (PVP-I) has been demonstrated recently to reduce SARS-CoV-2 viral titres. This study evaluated the virucidal activity of the aqueous solution of Iodine-V (a clathrate complex formed by elemental iodine and fulvic acid) as in Essential Iodine Drops (EID) with 200 μg elemental iodine/ml content against SARS-CoV-2 to ascertain whether it is a better alternative to PVP-I.MethodsSARS-CoV-2 (USAWA1/2020 strain) virus stock was prepared by infecting Vero 76 cells (ATCC CRL-1587) until cytopathic effect (CPE). The virucidal activity of EID against SARS-CoV-2 was tested in three dilutions (1:1; 2:1 and 3:1) in triplicates by incubating at room temperature (22 ± 2°C) for either 60 or 90 seconds. The surviving viruses from each sample were quantified by a standard end-point dilution assay.ResultsEID (200 μg iodine/ml) after exposure for 60 and 90 seconds was compared to controls. In both cases, the viral titre was reduced by 99% (LRV 2.0). The 1:1 dilution of EID with virus reduced SARS-CoV-2 virus from 31,623 cell culture infectious dose 50% (CCCID50) to 316 CCID50 within 90 seconds.ConclusionSubstantial reductions in LRV by Iodine-V in EID confirmed the activity of EID against SARS-CoV-2 in vitro, demonstrating that Iodine-V in EID is effective at inactivating the virus in vitro and therefore suggesting its potential application intranasally to reduce SARS-CoV-2 transmission from known or suspected COVID-19 patients.

scholarly journals Virucidal Efficacy of Different Oral Rinses Against Severe Acute Respiratory Syndrome Coronavirus 2

2020 ◽  
Vol 222 (8) ◽  
pp. 1289-1292 ◽  
Author(s):  
Toni Luise Meister ◽  
Yannick Brüggemann ◽  
Daniel Todt ◽  
Carina Conzelmann ◽  
Janis A Müller ◽  
...  
Keyword(s):  
Viral Load ◽  
Severe Acute Respiratory Syndrome ◽  
Global Health ◽  
Salivary Glands ◽  
Virus Replication ◽  
Virucidal Activity ◽  
Antiviral Efficacy ◽  
Virucidal Efficacy

Abstract The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic creates a significant threat to global health. Recent studies suggested the significance of throat and salivary glands as major sites of virus replication and transmission during early coronavirus disease 2019, thus advocating application of oral antiseptics. However, the antiviral efficacy of oral rinsing solutions against SARS-CoV-2 has not been examined. Here, we evaluated the virucidal activity of different available oral rinses against SARS-CoV-2 under conditions mimicking nasopharyngeal secretions. Several formulations with significant SARS-CoV-2 inactivating properties in vitro support the idea that oral rinsing might reduce the viral load of saliva and could thus lower the transmission of SARS-CoV-2.

scholarly journals Neutralizing Human Antibodies against Severe Acute Respiratory Syndrome Coronavirus 2 Isolated from a Human Synthetic Fab Phage Display Library

2021 ◽  
Vol 22 (4) ◽  
pp. 1913
Author(s):  
Yu Jung Kim ◽  
Min Ho Lee ◽  
Se-Ra Lee ◽  
Hyo-Young Chung ◽  
Kwangmin Kim ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Phage Display ◽  
Viral Entry ◽  
Phage Display Library ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Receptor Protein ◽  
In Vitro Assays ◽  
Global Threat

Since it was first reported in Wuhan, China, in 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic outbreak resulting in a tremendous global threat due to its unprecedented rapid spread and an absence of a prophylactic vaccine or therapeutic drugs treating the virus. The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein is a key player in the viral entry into cells through its interaction with the angiotensin-converting enzyme 2 (ACE2) receptor protein, and the RBD has therefore been crucial as a drug target. In this study, we used phage display to develop human monoclonal antibodies (mAbs) that neutralize SARS-CoV-2. A human synthetic Fab phage display library was panned against the RBD of the SARS-CoV-2 spike protein (SARS-2 RBD), yielding ten unique Fabs with moderate apparent affinities (EC50 = 19–663 nM) for the SARS-2 RBD. All of the Fabs showed no cross-reactivity to the MERS-CoV spike protein, while three Fabs cross-reacted with the SARS-CoV spike protein. Five Fabs showed neutralizing activities in in vitro assays based on the Fabs’ activities antagonizing the interaction between the SARS-2 RBD and ACE2. Reformatting the five Fabs into immunoglobulin Gs (IgGs) greatly increased their apparent affinities (KD = 0.08–1.0 nM), presumably due to the effects of avidity, without compromising their non-aggregating properties and thermal stability. Furthermore, two of the mAbs (D12 and C2) significantly showed neutralizing activities on pseudo-typed and authentic SARS-CoV-2. Given their desirable properties and neutralizing activities, we anticipate that these human anti-SARS-CoV-2 mAbs would be suitable reagents to be further developed as antibody therapeutics to treat COVID-19, as well as for diagnostics and research tools.

scholarly journals Discovery of Clioquinol and Analogues as Novel Inhibitors of Severe Acute Respiratory Syndrome Coronavirus 2 Infection, ACE2 and ACE2 - Spike Protein Interaction In Vitro

2020 ◽  
Author(s):  
Omonike A. Olaleye ◽  
Manvir Kaur ◽  
Collins Onyenaka ◽  
Tolu Adebusuyi
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Cytopathic Effect ◽  
Molecular Target ◽  
Clinical Development ◽  
Spike Protein ◽  
Angiotensin Converting Enzyme 2 ◽  
Global Pandemic ◽  
Potential Therapeutics ◽  
Micromolar Range

AbstractSevere Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the etiological agent for coronavirus disease 2019 (COVID-19), has emerged as an ongoing global pandemic. Presently, there are no clinically approved vaccines nor drugs for COVID-19. Hence, there is an urgent need to accelerate the development of effective antivirals. Here in, we discovered Clioquinol (5-chloro-7-iodo-8-quinolinol (CLQ)), a FDA approved drug and two of its analogues (7-bromo-5-chloro-8-hydroxyquinoline (CLBQ14); and 5, 7-Dichloro-8-hydroxyquinoline (CLCQ)) as potent inhibitors of SARS-CoV-2 infection induced cytopathic effect in vitro. In addition, all three compounds showed potent anti-exopeptidase activity against recombinant human angiotensin converting enzyme 2 (rhACE2) and inhibited the binding of rhACE2 with SARS-CoV-2 Spike (RBD) protein. CLQ displayed the highest potency in the low micromolar range, with its antiviral activity showing strong correlation with inhibition of rhACE2 and rhACE2-RBD interaction. Altogether, our findings provide a new mode of action and molecular target for CLQ and validates this pharmacophore as a promising lead series for clinical development of potential therapeutics for COVID-19.

scholarly journals Povidone-iodine demonstrates rapid in-vitro virucidal activity against SARS-CoV-2, the virus causing COVID-19 disease

2020 ◽  
Author(s):  
Danielle E. Anderson ◽  
Velraj Sivalingam ◽  
Adrian Eng Zheng Kang ◽  
Abhishek Ananthanarayanan ◽  
Harsha Arumugam ◽  
...  
Keyword(s):  
Hand Hygiene ◽  
Povidone Iodine ◽  
Control Measures ◽  
Physical Contact ◽  
Virucidal Activity ◽  
Antiseptic Solution ◽  
Infection Control Measures ◽  
Mouth Wash ◽  
Oral Decontamination

Abstract Introduction: Within six months of its emergence, SARS‑CoV‑2 has infected 5.5 million people worldwide, causing >345,000 deaths. The virus is transmitted through respiratory droplets and physical contact from contaminated surfaces to the mucosa. Hand hygiene and oral decontamination among other measures are key to preventing the spread of the virus. We report the in-vitro virucidal activity of topical and oral povidone-iodine (PVP‑I) products against SARS‑CoV‑2.Methods: Suspension assays were used to assess the virucidal activity of PVP‑I against SARS‑CoV‑2. Products were tested at a contact time of 30 seconds for virucidal activity. Viral titres were calculated using the Spearman-Kärber method and reported as TCID50/mL.Results: All four products (antiseptic solution [PVP-I 10%], skin cleanser [PVP-I 7.5%], gargle and mouth wash [PVP-I 1%] and throat spray [PVP-I 0.45%] achieved ≥99.99% virucidal activity against SARS-CoV-2, corresponding to ≥4 log10 reduction of virus titre, within 30 seconds of contact.Conclusion: This study provides evidence of rapid and effective virucidal activity of PVP-I against SARS-CoV-2. PVP-I-based products are widely available for medical and personal use for hand hygiene and oral decontamination and could be readily integrated into COVID-19 infection control measures in hospital and community settings.

scholarly journals SARS-CoV-2 invades host cells via a novel route: CD147-spike protein

2020 ◽  
Author(s):  
Ke Wang ◽  
Wei Chen ◽  
Yu-Sen Zhou ◽  
Jian-Qi Lian ◽  
Zheng Zhang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Severe Acute Respiratory Syndrome ◽  
Research Finding ◽  
Antiviral Drugs ◽  
Host Cells ◽  
Spike Protein ◽  
Affinity Constant ◽  
Humanized Antibody ◽  
The World

SUMMARYCurrently, COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been widely spread around the world; nevertheless, so far there exist no specific antiviral drugs for treatment of the disease, which poses great challenge to control and contain the virus. Here, we reported a research finding that SARS-CoV-2 invaded host cells via a novel route of CD147-spike protein (SP). SP bound to CD147, a receptor on the host cells, thereby mediating the viral invasion. Our further research confirmed this finding. First, in vitro antiviral tests indicated Meplazumab, an anti-CD147 humanized antibody, significantly inhibited the viruses from invading host cells, with an EC50 of 24.86 μg/mL and IC50 of 15.16 μg/mL. Second, we validated the interaction between CD147 and SP, with an affinity constant of 1.85×10−7M. Co-Immunoprecipitation and ELISA also confirmed the binding of the two proteins. Finally, the localization of CD147 and SP was observed in SARS-CoV-2 infected Vero E6 cells by immuno-electron microscope. Therefore, the discovery of the new route CD147-SP for SARS-CoV-2 invading host cells provides a critical target for development of specific antiviral drugs.

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