SARS-CoV-2 membrane bursts with some mouthwashes

A study has made it possible to visualize for the first time that the SARS-CoV-2 membrane bursts when it comes into contact with a chemical compound present in some mouthwashes. This would have the consequence that the virus decreases its ability to infect human cells.

The study, carried out by the Universitat de València (UV) in eastern Spain and the Dentaid Research Center, determines that this membrane breakdown occurs upon contact with Cetylpyridinium Chloride (CPC), present in some mouthwashes, according to a statement from the academic institution.

The study was published in the ‘Journal of Oral Microbiology.’

Sars-CoV-2 viral load

According to the sources, the SARS-CoV-2 virus has been shown to have a strong affinity for oral tissues and actively replicates in the salivary glands; the saliva of infected individuals normally has a high virus load.

Reducing the viral load in the mouth could be a strategy to reduce its spread. In this sense, several studies have shown that some mouthwashes can inactivate some viruses transmitted through the air, such as the flu, some coronaviruses, and even SARS-CoV-2.

Numerous dental societies have recommended using CPC mouthrinses to help decrease the risk of SARS-CoV-2 transmission.

Now, the study completes these investigations and explains the mechanism of the antiviral activity of the CPC molecule. The results show that the antiviral action of CPC is produced thanks to its ability to break the membrane of SARS-CoV-2 and, as has been demonstrated in other studies, would have the consequence that the virus decreases its ability to infect human cells.

A research group signs the study from the Department of Biochemistry and Molecular Biology of Valencia. Headed by Professor Ismael Mingarro , and by researchers Manuel Bañó and Rubén León , from the Dentaid Research Center.

The mechanism of antiviral activity of CPC

The study generated pseudo viral particles (VLPs) that mimic the SARS-CoV-2 virus. They contain the four structural proteins of the virus and have the size and morphology of the viral particles of the virus that causes covid-19. The only difference with the SARS-CoV-2 virions is that the VLPs do not contain the genetic material, making them non-infective. The generated VLPs were treated with CPC, and it was observed how those in contact with the CPC were disaggregated, explains Ismael Mingarro. “The disintegration was observed using electron microscopy techniques, where it was possible to demonstrate how these particles burst when they come into contact with the CPC,” he points out.

Furthermore, the results demonstrate that CPC significantly decreases the integrity of SARS-CoV-2 VLPs at a concentration as low as 0.05%. “These results corroborate the mechanism of action by which Cetylpyridinium Chloride (CPC) would act on the SARS-CoV-2 membrane, causing its degradation,” explains Manuel Bañó, a researcher at the Dentaid Research Center. CPC is a critical ingredient in many types of mouthwash that works as an antiseptic that kills bacteria and other microorganisms, such as viruses.

“This work explains the mechanism by which CPC can degrade the SARS-CoV-2 membrane. It is important because it lays the foundations for future experiments in which to demonstrate that the use of mouthwashes is a complementary strategy to prevent the transmission of respiratory infectious diseases transmitted by viruses such as the flu or covid-19,” adds Bañó. Ismael Migarro is a professor of Biochemistry and Molecular Biology at the UV, and his research is focused on membrane proteins.