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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.
The full study was co-authored by Takumi Satoh of the Tokyo University of Technology; and by Dorit Trudler, Chang-ki Oh and Stuart Lipton of Scripps Research. Read the source news release here.
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.
The Stem Cellar 
All cells require oxygen, the oxidation in the human body to produce energy for functioning of cells. However, the metabolism of oxygen may produce unstable molecules or free radicals, which causing damage to DNA and other structures including cellular protein and lipids. The overloading of free radicals overtime may cause irreversible and lead to diseases and cancers. Thus, free radicals have been linked to a variety of diseases and antioxidants can neutralise those free radicals. Therefore, diet high in antioxidants may reduce risk of many diseases and cancers. Evidence showed that antioxidants supplement do not work as well as naturally occurring antioxidants in foods
Rosemary extract (CA) is a potent antioxidant and anti-inflammation. Experimental study showed that CA can regulate ER stress, oxidative stress and suppressive of NLPR3 inflammasome which is a potential contributor to cytokine storm in Covid-19 patients. Further investigation showed CA was potentially inhibit SAR-CoV-2 infection by modulating the binding site of spikes protein and ACE. Although experimental study showed CA is a potential therapeutic treatment for covid-19 disease but clinical setting is essentially to support the effectiveness of medication. The modulation of binding site between spikes protein and ACE required more evidence to support chemical reaction of CA to inhibit infection of Covid-19. Receptor binding assay can be considered a significant approach to determine the specific binding site of ACE and mechanism study is critical to determine whether CA has ability to bind to extracellular or intracellular domains which can effectively cause inhibition of viral infection.