Green tea and black tea effective against Omicron variants of the COVID-19 virus: Study

In a recent study published in Scientific Reports, it was revealed that green tea, Matcha, and black tea were effective in inactivating Omicron subvariants. The findings build upon previous research demonstrating the efficacy of these compounds in inactivating conventional SARS-CoV-2 by binding to the receptor binding domain (RBD) of the S-protein.

(−)-epigallocatechin gallate or EGCG and theaflavin-3,3’-di-O-digallat or TFDG, which are tea catechins exhibited strong inhibitory effects on the BA.1 and XE subvariants, while their impact on BA.2.75 was comparatively weaker. Further investigation through a neutralization assay unveiled that EGCG and TFDG hindered the interaction between the BA.1 receptor binding domain and ACE2, a crucial receptor for viral entry.

In silico analyses provided insights into the specific amino acid substitutions within the receptor binding domains that critically influenced the binding of EGCG and TFDG to the receptor binding domains. These findings lay the groundwork for understanding the varying susceptibility of Omicron subvariants to these tea compounds.

To bridge the gap between laboratory research and real-world application, healthy volunteers consumed candies containing green tea or black tea. Saliva samples collected immediately after consumption demonstrated a significant reduction in BA.1 virus infectivity in vitro. The study not only showcases the potential of tea compounds in combatting SARS-CoV-2 subvariants but also provides valuable insights into the molecular basis of their effectiveness.

Reference: Shin-Ya, M., Nakashio, M., Ohgitani, E. et al. Effects of tea, catechins and catechin derivatives on Omicron subvariants of SARS-CoV-2. Sci Rep 13, 16577 (2023). https://doi.org/10.1038/s41598-023-43563-3