Differential effects of antiseptic mouth rinses on SARS-CoV-2 infectivity in vitro

  1. Chuan Xu
  2. Annie Wang
  3. Eileen R. Hoskin
  4. Carla Cugini
  5. Kenneth Markowitz
  6. Theresa L. Chang
  7. Daniel H. Fine

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Abstract

SARS-CoV-2 is detectable in saliva from asymptomatic individuals, suggesting a potential benefit from the use of mouth rinses to suppress viral load and reduce virus spread. Published studies on reduction of SARS-CoV-2-induced cytotoxic effects by antiseptics do not exclude antiseptic-associated cytotoxicity. Here, we determined the effect of commercially available mouth rinses and antiseptic povidone-iodine on the infectivity of SARS-CoV-2 virus and of a non-pathogenic, recombinant, SARS-CoV-2 infection vector (pseudotyped SARS-CoV-2 virus). We first determined the effect of mouth rinses on cell viability to ensure that antiviral activity was not a consequence of mouth rinse-induced cytotoxicity. Colgate Peroxyl (hydrogen peroxide) exhibited the most cytotoxicity, followed by povidone-iodine, chlorhexidine gluconate (CHG), and Listerine (essential oils and alcohol). Potent anti-viral activities of povidone iodine and Colgate peroxyl mouth rinses was the consequence of rinse-mediated cellular damage. The potency of CHG was greater when the product was not washed off after virus attachment, suggesting that the prolonged effect of mouth rinses on cells impacts anti-viral activity. To minimalize mouth rinse-associated cytotoxicity, mouth rinse was largely removed from treated-viruses by centrifugation prior to infection of cells. A 5% (v/v) dilution of Colgate Peroxyl or povidone-iodine completely blocked viral infectivity. A similar 5% (v/v) dilution of Listerine or CHG had a moderate suppressive effect on the virus, but a 50% (v/v) dilution of Listerine or CHG blocked viral infectivity completely. Prolonged incubation of virus with mouth rinses was not required for viral inactivation. Our results indicate that mouth rinses can significantly reduce virus infectivity, suggesting a potential benefit for reducing SARS-CoV-2 spread.

Importance

SARS-CoV-2 is detectable in saliva from asymptomatic individuals, suggesting the potential necessity for the use of mouth rinses to suppress viral load to reduce virus spread. Published studies on anti-SARS-CoV-2 activities of antiseptics determined by virus-induced cytotoxic effects cannot exclude antiseptic-associated cytotoxicity. We found that all mouth rinses tested inactivated SARS-CoV-2 viruses. Listerine and CHG were less cytotoxic than Colgate Peroxyl or povidone-iodine and were active against the virus. When mouth rinses were present in the cell culture during the infection, the potent anti-viral effect of mouth rinses were in part due to the mouth rinse-associated cytotoxicity. Our results suggest that assessing anti-viral candidates including mouth rinses with minimal potential disruption of cells may help identify active agents that can reduce SARS-CoV-2 spread.

Article activity feed

  1. Rapid Reviews Infectious Diseases

    Chaminda Seneviratne

    Review 2: "Differential effects of antiseptic mouth rinses on SARS-CoV-2 infectivity in vitro"

    This potentially informative in-vitro study finds that some commercially available mouth-rinses have different anti-viral activity/cytotoxicity. Additional animal models and clinical trials are needed to generalize the study’s findings.

  2. Rapid Reviews Infectious Diseases

    Florence Carrouel

    Review 1: "Differential effects of antiseptic mouth rinses on SARS-CoV-2 infectivity in vitro"

    This potentially informative in-vitro study finds that some commercially available mouth-rinses have different anti-viral activity/cytotoxicity. Additional animal models and clinical trials are needed to generalize the study’s findings.

  4. ScreenIT

    SciScore for 10.1101/2020.12.01.405662: (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.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Monoclonal antibody (Ab) against SARS-CoV-2 spike protein (IgG1 clone#43, Cat # 40591-MM43) was purchased from Sino Biological, Inc (Wanye, PA)
    SARS-CoV-2 spike protein ( IgG1 clone#43 , Cat # 40591-MM43 )
    suggested: None
    SARS-CoV-2 spike protein
    suggested: None
    IgG1
    suggested: (Sino Biological Cat# 40591-MM43, RRID:AB_2857934)
    Experimental Models: Cell Lines
    SentencesResources
    Cell culture: HEK293T cells and human angiotensin-converting enzyme 2 (hACE2)-expressing HeLa cells (kindly provided by Dennis Burton; The Scripps Research Institute, La Jolla, CA) were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with 10% fetal bovine serum (FBS).
    HEK293T
    suggested: None
    HeLa
    suggested: None
    Vero E6 cells were cultured in Eagle’s Essential Minimal Medium (EMEM) with 5% FBS.
    Vero E6
    suggested: RRID:CVCL_XD71)
    Pseudotyped SARS-CoV2 luciferase reporter viruses were incubated with or without mouth rinse for 30 min at 37°C before being added to HeLa-hACE2 cells.
    HeLa-hACE2
    suggested: None
    Software and Algorithms
    SentencesResources
    Prism 8 (GraphPad Software, LLC) was used. p < 0.05 was considered significant.
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)

    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: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    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.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • 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.

  5. Version published to 10.1101/2020.12.01.405662v1 on bioRxiv