Mouthwashes have an effect on the novel coronavirus. Credit: © RUB, Marquard
Results of cell culture experiments show that commercially available preparations have an effect on Sars-Cov-2 viruses.
Sars-Cov-2 viruses can be inactivated with certain commercially available mouthwashes. This was demonstrated in experiments for cell culture by virologists from Ruhr-Universität Bochum together with colleagues from Jena, Ulm, Duisburg-Essen, Nuremberg and Bremen. High viral load can be detected in the oral cavity and throat of some Covid-19 patients.
The use of mouthwashes that are effective against Sars-Cov-2 could thus help to reduce the viral load and possibly the risk of coronavirus transmission over the short term. This can be handy, for example, prior to dental treatments. However, mouthwashes are not suitable for treating Covid-19 infections or to protect yourself from catching the virus.
The results of the study are described by the team led by Toni Meister, Professor Stephanie Pfänder and Professor Eike Steinmann of the research group Molecular and Medical Virology in Bochum in the Journal of Infectious Diseases, published online on July 29, 2020. In review of laboratory results in clinical trials is pending.
Eight mouthwashes in a cell culture test
The researchers tested eight mouthwashes with various ingredients available in pharmacies and drugstores in Germany. They mixed each mouthwash with virus particles and an interfering substance, which was intended to replicate the effect of saliva in the mouth. The mixture was then shaken for 30 seconds to simulate the effect of giggling. They then used Vero E6 cells, which are particularly receptive to Sars-Cov-2, to determine the virus titer. To assess the effectiveness of the mouthwashes, the researchers also treated the virus suspensions with cell culture medium instead of the mouthwash before adding them to the cell culture.
All tested preparations reduced the initial virus titer. Three mouthwashes reduced it to such an extent that no virus could be detected after an exposure time of 30 seconds. Whether this effect is confirmed in clinical practice and how long it lasts should be investigated in further studies.
The authors indicate that mouthwashes are not suitable for treatment of Covid-19. “Gargling with a mouthwash may not interfere with the production of viruses in the cells,” explains Toni Meister, “but it could reduce the viral load in the short term where the greatest potential for infection occurs, namely in the oral cavity and throat – and this can be helpful in certain situations, such as at the dentist or during the medical care of Covid-19 patients. ”
Clinical studies in progress
The Bochum group is investigating the possibilities of a clinical study on the effectiveness of mouthwashes on Sars-Cov-2 viruses, in which the scientists want to test whether the effect can also be detected in patients and how long it lasts. Similar studies are already underway in San Francisco; the Bochum team is in contact with the American researchers.
###
Reference: “Virusidal efficacy of various oral lavages against SARS-CoV-2”From Toni Luise Meister, Yannick Brüggemann, Daniel Todt, Carina Conzelmann, Janis A Müller, Rüdiger Groß, Jan Münch, Adalbert Krawczyk, Jörg Steinmann, Jochen Steinmann, Stephanie Pfaender and Eike Steinmann, 29 July 2020, The Journal of Infectious Diseases.
DOI: 10.1093 / infdis / jiaa471
The work was funded by the European Union as part of the Horizon 2020 program (grant number 101003555) and by Stiftung Universitätsmedizin Essen.
