A recent study suggests that green tea, matcha, and black tea may effectively deactivate the highly transmissible sub-variants of the Omicron variant of the SARS-CoV-2 virus, which causes COVID-19.
Previous research has demonstrated that tea catechins, which are biologically active compounds found in tea, can effectively deactivate the SARS-CoV-2 virus. In this new study, published in the journal Scientific Reports, healthy volunteers consumed a candy containing either green tea or black tea. Saliva samples collected from these volunteers immediately after consuming the candy showed a significant reduction in the infectivity of the virus in vitro.
Osam Mazda, from the Department of Immunology at Kyoto Prefectural University of Medicine in Japan, stated, “We found that all the Omicron subvariants that we tested were efficiently inactivated by treatment with green tea, Matcha green tea, and black tea.” He added that this study may indicate a molecular basis for the potential usefulness of these compounds in suppressing mutant viruses that could potentially cause future pandemics.
The research revealed that tea catechins, particularly (-)-epigallocatechin gallate (EGCG) and its derivative theaflavin-3,3′-di-O-digallate (TFDG), strongly suppressed the infectivity of certain Omicron subvariants, with a slightly weaker effect on others. Neutralization assays indicated that EGCG and TFDG inhibited the interaction between the spike protein receptor-binding domain (RBD) of the BA.1 subvariant and the ACE2 receptor.
In-silico analysis, which involves computer-based simulations and modeling, suggested that specific amino acid substitutions in the RBDs, such as N460K, G446S, and F490S mutations, played a crucial role in influencing the binding of EGCG and TFDG to the RBDs. These results indicate that different Omicron subvariants may exhibit varying susceptibilities to EGCG and TFDG due to specific amino acid changes in their RBDs.
The study’s findings suggest that candies containing green tea or black tea may be useful in inactivating the virus if consumed by infected individuals. This could potentially reduce the virus load in the oral cavity and gastrointestinal tract of the infected person and help prevent the spread of the virus to nearby non-infected individuals.
While this research is promising, it’s important to note that these findings are based on laboratory experiments and further clinical studies would be needed to determine the practical application of tea catechins in combating COVID-19 variants.