Researchers from the CSIR-Institute of Himalayan Bioresource Technology in Palampur have identified organic chemicals in tea plants that could be potentially used to stop the proliferation of the novel coronavirus1.
They have found that the chemicals, known as polyphenols, bind to a specific viral protein more efficiently than three commercially available anti-HIV drugs approved for treating COVID-19 patients.
These chemicals, they say, might block the activity of the viral protein that helps the virus to thrive inside human cells.
Tea polyphenols have been shown to inhibit the growth of the human immunodeficiency virus (HIV). These chemicals also possess anticancer and antidiabetic properties. However, their roles against the coronaviruses, particularly the novel coronavirus, were largely unexplored.
Using computer-based models, the scientists screened 65 bioactive chemicals found in tea plants. They then tested these chemicals’ efficiency in binding to the main protease, one of the proteins that the coronavirus uses to grow inside human cells.
They detected a few polyphenols that could bind efficiently to the viral protein. Of the effective polyphenols, theaflavin-3-O-gallate, oolonghomobisflavan-A and theasinensin-D formed stable bonds with the viral protein. They found that the bonds between the polyphenols and the viral protein were stronger than those formed by anti-HIV drugs such as atazanavir, darunavir and lopinavir.
The researchers say that olonghomobisflavan-A formed the strongest bond with the viral protein. This polyphenol could outperform the anti-HIV drugs in inhibiting the activity of the viral protein, they add.
1. Bharadwaj, K. V. et al. Identification of bioactive molecules from Tea plant as SARS-CoV-2 main protease inhibitors. J. Biomol. Struct. Dynam. (2020) doi: 10.1080/07391102.2020.1766572