//Can common mouthwash help fight Covid-19?
covid-19 mouthwash

Can common mouthwash help fight Covid-19?

Scientists at Cardiff University found there were “promising signs” that over-the-counter mouthwashes may help to destroy the virus. While the research suggests use of mouthwash may help kill the virus in saliva, there is not evidence it could be used as a treatment for coronavirus, as it will not reach the the respiratory tract or the lungs. Dr Claydon, a specialist periodontologist, said: “If these positive results are reflected in Cardiff University’s clinical trial, CPC-based mouthwashes… could become an important addition to people’s routine, together with hand washing, physical distancing and wearing masks, both now and in the future.”

Here’s more on the study looking at mouthwash as a tool in fighting Covid-19:

Study Abstract

The ability of widely-available mouthwashes to inactivate SARS-CoV-2 in vitro was tested using a protocol capable of detecting a 5-log10 reduction in infectivity, under conditions mimicking the naso/oropharynx. During a 30 second exposure, two rinses containing cetylpyridinium chloride and a third with ethanol/ethyl lauroyl arginate eliminated live virus to EN14476 standards (>4-log10 reduction), while others with ethanol/essential oils and povidone-iodine (PVP-I) eliminated virus by 2-3- log10. Chlorhexidine or ethanol alone had little or no ability to inactivate virus in this assay. Studies are warranted to determine whether these formulations can inactivate virus in the human oropharynx in vivo, and whether this might impact transmission.

Some of the mouthwash that contains cetylpyridinium chloride include:

  • Dentyl mouthwash
  • Crest pro-health multi-protection mouthwash
  • Colgate Total Pro-Shield
  • Sensodyne Pronamel Daily Mouthwash
  • Oral-B Pro-Expert Multi Protection alcohol free mouthwash
  • Colgate Plax Cool Mint
  • OraCare+ Senstiive alcohol-free fluoride mouth wash

Results

In initial experiments, we examined the effect of mouthwashes on the VeroE6/ACE2/TMPRSS2 monolayers used to detect live virus, following serial dilution in DMEM. Four of the seven productsdemonstrated toxicity to the monolayer, which was not eliminated until they were diluted at least 100-1000-fold, limiting the sensitivity of the assay to measure residual infectivity. We therefore usedsize-exclusion chromatography (SEC) to rapidly purify virus away from the products. When virus was purified on S-400 HR microspin columns, only minimal loss of infectivity was observed (Fig 1A), however toxicity from the mouthwashes against the cell monolayer was virtually eliminated (Fig 1B). SEC was therefore used for all assays from this point forwards. This approach also ensures that the activity of the mouthwashes against the virus was rapidly stopped after the desired co-incubation time. In comparison, our results suggest that ‘stopping’ the reaction by serial 10-fold dilution would leave sufficient mouthwash activity to have continued biological activity against the virus. Combined with the use of VeroE6/ACE2/TMPRSS2 cells for titration, which SARS-COV2 enters >1log more efficiently than parental VeroE6, the assay was capable of detecting a 5-log10 decrease in virus titre. This is more than sufficient to detect the 4-log10 reduction in activity specified by EN14476.