The culinary herb rosemary is commonly used in our kitchens to season an array of dishes, and is also considered a good source for vitamins and minerals.
Rosemary is also valued for its medicinal properties, and has traditionally been used to help alleviate muscle pain, boost the immune and circulatory system, as well as many other health benefits.
Now, scientists at Scripps Research have found evidence that a compound contained in rosemary could be a two-pronged weapon against the SARS-CoV-2 coronavirus that causes COVID-19.
The research was partly funded by the California Institute for Regenerative Medicine (CIRM).
Published in the journal Antioxidants, the study found that the compound, carnosic acid, can block the interaction between the SARS-CoV-2 outer “spike” protein and the receptor protein, ACE2, which the virus uses to gain entry to cells.
“We think that carnosic acid, or some optimized derivative, is worth investigating as a potentially cheap, safe, and effective treatment for COVID-19 and some other inflammation-related disorders,” says study senior author Dr. Stuart Lipton of Scripps Research.
The team also reviewed prior studies and presented new evidence that carnosic acid could inhibit a powerful inflammatory pathway that is active in severe COVID-19, as well as in other diseases including Alzheimer’s.
They also proposed that this effect could be beneficial in treating the post-COVID syndrome known as “long COVID” whose reported symptoms include cognitive difficulties often described as “brain fog.”
While the research is preliminary, the researchers propose that carnosic acid has this antiviral effect because it is converted to its active form by the inflammation and oxidation found at sites of infection. In that active form, they suggest, the compound modifies the ACE2 receptor for SARS-CoV-2—making the receptor impregnable to the virus and thereby blocking infection.
Lipton and his colleagues are now working with Scripps Research chemists to synthesize and test more potent derivatives of carnosic acid with improved drug characteristics for potential use in inflammation-related disorders.
Disclaimer: This research is still in its early phase and there is no suggestion that sprinkling rosemary on everything you eat could help prevent or fight COVID-19. For the latest guidance on COVID-19, see the official CDC website.