A Nasal Spray Solution of Grapefruit Seed Extract plus Xylitol Displays Virucidal Activity Against SARS-Cov-2 In Vitro

  1. Gustavo Ferrer
  2. Arian Betancourt
  3. Camille Celeste Go
  4. Hector Vazquez
  5. Jonna B. Westover
  6. Valeria Cagno
  7. Caroline Tapparel
  8. Marcos A. Sanchez-Gonzalez

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Abstract

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the ongoing pandemic coronavirus disease 2019 (COVID-19) has triggered worldwide concerted efforts in an attempt to identify effective therapies. In the present study, we have identified two candidate agents with potential activity against SARS-CoV-2 which can be administered intranasally, namely, xylitol and grape seed fruit extract (GSE). A commercially available nasal spray (Xlear) combining xylitol and GSE has been available for years, but the antiviral effects of this solution have not been documented. This in vitro study examined the virucidal effect of Xlear against SARS-CoV-2. To this end, two independent sets of experiments were carried out to test the hypothesis that Xlear is an effective (Experiment I) and replicable (Experiment II) means to deactivate SARS-CoV-2. When tested against SARS-CoV-2, the test compound GSE 0.2% was the only compound effective at reducing >3 log10 CCID50 infectious virus from, 3.67 log10 CCID50/0.1 mL to an undetectable amount of infectious virus. The present results validated by two independent sets of experiments, performed by different labs, on different viral strains, provide early evidence to encourage further pilot and clinical studies aimed at investigating the use of Xlear as a potential treatment for COVID-19

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  1. ScreenIT

    SciScore for 10.1101/2020.11.23.394114: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    As with any research study, the present experimental design is not free from some limitations. The minimum time required for the Xlear solution to exert the virucidal effect was not investigated. Furthermore, to assess the relevance of the time-dependent effect of Xylitol effect in vivo, it will be important to verify if the addition of the spray-on cells previously infected at nontoxic doses would exert a reduction of the viral titer. Also, whether pre-treating the cells with the spray and subsequently adding the virus would decrease the rate of infection would be needed to assess the possible preventive use of the nasal spray.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We found bar graphs of continuous data. We recommend replacing bar graphs with more informative graphics, as many different datasets can lead to the same bar graph. The actual data may suggest different conclusions from the summary statistics. For more information, please see Weissgerber et al (2015).

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • No funding statement was detected.
    • No protocol registration statement was detected.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1101/2020.11.23.394114v1 on bioRxiv