Some substances contained in green tea, muscat grapes, bitter cocoa powder and dark chocolate have been shown to inhibit an enzyme used by the SARS-Cov-2 virus to replicate. This is what North Carolina State University researchers have observed and the study results are available online in the journal Frontiers in Plant Science (Zhu et al, Front Plant Sci, 30 Nov 2020).
Plants develop particular antioxidant substances, such as flavanols and proanthocyanidins, to protect themselves from external threats such as parasites, molds and fungi. These substances are mainly contained in the leaves and in the outer shells.
Therefore, the researchers wondered if these same substances that protect plants can also protect humans from external attacks as in the case of the new coronavirus. So, studies based on computer simulations and experiments in the laboratory were performed to evaluate how the different antioxidants interact with the virus. The new coronavirus has, in particular, proteins on its surface that allow it to enter the cell and replicate. One of these proteins, called Mpro, is also the main protein that allows the coronavirus to proliferate. Mpro is characterized by a pocket that, when filled, loses its function, the viral replication activity of Mpro is inhibited and the virus dies. Well, scientists have observed that green tea contains as many as five compounds capable of binding at different points in the Mpro pocket, completely inhibiting it. Muscat grapes, thanks to the substances contained in the peel and seeds, have also been shown to completely inhibit the action of Mpro.
As for bitter cocoa powder and dark chocolate, the antioxidants contained in these foods were found to be able to inhibit the action of Mpro by up to 50%. These results were observed thanks to computer simulations and then confirmed by laboratory tests.
Here is another proof of how particular food choices can support the immune system in case of external aggressions.