Scientists Are Testing Compound in Rosemary as Antiviral Treatment for COVID-19

Rosemary has served its purpose as food garnish or for medicinal use for thousands of years. As luck would have it, an investigation finds early evidence of COVID-19 treatment in the herb's compounds.

Researchers are intrigued to find antiviral effects in most of the molecules found in Rosemary that might "deal a blow against Covid-19" in two different ways, as per IFLScience. Its carnosic acid (CA), particularly, has inspired the team from the Scripps Institute to further do research on the potential application of Rosemary (Rosmarinus officinalis) in COVID-19 treatment.

Since Roman times, Rosemary's oils have been used in traditional medicines. In fact, carnosic acid, which makes up about 2 percent of its dry weight, had already been investigated for its anti-inflammatory effects on the brain even before the pandemic hit.

The new research in the journal Antioxidants shows that carnosic acid could have anti-COVID-19 properties, as well as positive implications in Alzheimer's and Parkinson's disease.

Carnosic acid disrupts SARS-CoV-2's capacity to infect cells

Senior author Professor Stuart Lipton said in Scripps Institute's website 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."

In addition, according to author Dr Chank-ki Oh, carnosic acid "interferes with SARS-CoV-2's capacity to infect cells" and is "almost 90 percent effective in blocking SARS-CoV-2 infection."

Derivative carnosol, also a compound found in Rosemary, also inhibits NLRP3 inflammation linked to the cytokine storms that pose a threat during acute COVID, and the "brain fog" and anxiety commonly associated with Covid. In addition, the team proposed that CA-related compounds may serve as therapeutics against the brain-related after-effects of SARS-CoV-2 infection, termed "long-COVID".

Professor Lipton described carnosic acid as showing signs of being a "pathologically activated therapeutic...inactive and innocuous in its normal state, but converted to an active form when it needs to be active."

Not a substitute for getting vaccinated

A test tube experiment could have different results when applied to humans, which is why most tests fail for one reason or another when transferred to living things. Carnosic acid could easily prove similarly disappointing, the Scripps team say, "so the only reason to be adding rosemary to your meals is if you like the flavor." However, they hope to find a solution that will eventually prove its worth and its benefits will be proved in time.

The review of evidence and mechanistic considerations supporting the future testing of rosemary extract is that its use is generally safe and exhibits no presence of side effects. In addition, the carnosic acid's health-promoting effects have been demonstrated in multiple animal models against chronic neurodegenerative disorders.

"CA exerts neuroprotective and anti-inflammatory effects and has been proposed to be a potential therapeutic against chronic neurodegenerative disorders, such as AD and PD, and acute and chronic effects of infections such as SARS-CoV-2," the authors wrote.

The study highlights two mechanisms in CA's manifestations of SARS-CoV-2, "one at the point of viral entry, possibly through covalent binding to the ACE2 receptor protein, and the other by ameliorating cytokine storm through the inhibition of NLRP3 inflammasome activation." Thus, the conclusion that the compound represents a potential therapeutic for COVID-19 as well as for neurodegenerative disorders.