Study: Chemical Compounds in Green Tea, Dark Chocolate May Inhibit a Key SARS-CoV-2 Enzyme


Proteases are important to the health and viability of cells and viruses. If proteases are inhibited, cells cannot perform many important functions, such as replication.

Chemical compounds found in foods or beverages, such as green tea and dark chocolate, can bind to and block the function of a particular protease in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enzyme, according to a new study by plant biologists at North Carolina State University.

Proteases are important to the health and viability of cells and viruses. If proteases are inhibited, cells cannot perform many important functions, such as replication, according to the study authors.

“One of our lab’s focuses is to find nutraceuticals in food or medicinal plants that inhibit either how a virus attaches to human cells or the propagation of a virus in human cells,” said Deyu Xie, PhD, professor of plant and microbial biology at NC State, in a press release.

The researchers performed both computer stimulations and lab studies showing how the “main protease” in the SARS-CoV-2 virus, or Mpro, reacted when confronted with a number of different plant chemical compounds already known for their potent anti-inflammatory and antioxidant properties.

“Mpro in SARS-CoV-2 is required for the virus to replicate and assemble itself,” Xie said in a press release. “If we can inhibit or deactivate this protease, the virus will die.”

The computer stimulations showed that the studied chemical compounds from green tea, 2 varieties of muscadine grapes, cacao powder, and dark chocolate were able to bind to different portions of Mpro.

Similar results were shown in vitro lab experiments completed by NC State PhD student Yue Zhu. Zhu found that the chemical compounds in green tea and muscadine grapes were very successful at inhibiting Mpro’s function, whereas chemical compounds in cacao powder and dark chocolate reduced Mpro activity by about half.

“Green tea has 5 tested chemical compounds that bind to different sites in the pocket on Mpro, essentially overwhelming it to inhibit its function,” Xie said in a press release. “Muscadine grapes contain these inhibitory chemicals in their skins and seeds. Plants use these compounds to protect themselves, so it is not surprising that plant leaves and skins contain these beneficial compounds.”


Chemical compounds in foods can inhibit a key SARS-CoV-2 enzyme. NC State University.,at%20North%20Carolina%20State%20University. Published November 30, 2020. Accessed December 2, 2020.

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