LA JOLLA, Calif. — A compound found in the medicinal and culinary herb rosemary may prove useful in the fight against COVID-19, according to a team from the Scripps Research Institute. Scientists report that carnosic acid, a substance in the tasty herb, may pack a one-two punch against SARS-CoV-2, the virus causing COVID.
The compound is capable of impeding interactions between the SARS-CoV-2 outer “spike” protein and the body’s receptor protein (ACE2). Coronavirus essentially uses the ACE2 receptor as an entry point into human cells.
Moreover, the research team also collected additional evidence suggesting carnosic acid also offers additional health benefits, as it can inhibit a powerful inflammatory pathway. This pathway just happens to also be quite active in severe COVID-19 cases, as well as various other diseases such as Alzheimer’s.
“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 Stuart Lipton, MD, PhD, Professor and Step Family Foundation Endowed Chair in the Department of Molecular Medicine and founding co-director of the Neurodegeneration New Medicines Center at Scripps Research, in a media release.
Rosemary compound acts like an anti-inflammatory
An earlier 2016 study conducted by Dr. Lipton found that carnosic acid activates an anti-inflammatory, antioxidant “signaling cascade” referred to as the Nrf2 pathway. That prior study also collected evidence suggesting carnosic acid can help relieve “Alzheimer’s-like signs in mouse models.”
For this newest research, study authors dived deeper into carnosic acid’s anti-inflammatory effect on immune cells connected with both COVID-19 and dementia. The team also included additional relevant data and evidence from other studies. In summation, the research team theorizes that carnosic acid may be beneficial in terms of fighting COVID-related inflammation, as well as long COVID symptoms.
Researchers also conducted a COVID-19 infection-blocking experiment. Using a standard infectivity assay, that experiment confirmed carnosic acid can indeed directly block SARS-CoV-2 from infecting cells. Notably, those infection-blocking abilities increase with higher doses of carnosic acid.
It’s important to stress that these findings are preliminary at this point. Still, study authors conclude carnosic acid likely offers useful antiviral properties, all while remaining totally safe and relatively unreactive. As far as why this is the case, carnosic acid is converted to its active form via inflammation, with oxidation being found at infection sites. Once active, researchers hypothesize carnosic acid changes the human body’s ACE2 receptors, blocking SARS-CoV-2 infection.
“Carnosic acid represents a ‘pathologically activated therapeutic’ in preclinical models of disease —inactive and innocuous in its normal state, but converted to an active form where it needs to be active,” Lipton concludes.
The study is published in the journal Antioxidants.