"Interestingly, eugenol, but not other constituents (e.g. ursolic acid, oleanolic acid and β-caryophylline), of tulsi leaf inhibits the interaction between ACE2 and viral spike S1", said Dr. Pahan.
CHICAGO, IL, November 02, 2021 /24-7PressRelease/ -- Holy basil or tulsi is mainly cultivated for religious and traditional medicine purposes. Now, scientists at the Rush University Medical Center (Chicago) show that one compound from tulsi leaf successfully controls lung inflammation, decreases fever, and recovers heart function in a mouse model of COVID-19.
Results of the study are just published in the Journal of Neuroimmune Pharmacology: https://link.springer.com/article/10.1007%2Fs11481-021-10028-1
"Understanding the mechanism is important to developing effective therapy for COVID-19," said Kalipada Pahan, PhD, the Floyd A. Davis Professor of Neurology at Rush and a Research Career Scientist at the Jesse Brown VA Medical Center.
Other authors of the article are Dr. Ramesh K. Paidi, Dr. Malabendu Jana, Dr. Sumita Raha, Mary McKay, and Monica Sheinin from Rush University Medical Center and Dr. Rama K. Mishra from Northwestern University.
Since spike S1 of SARS-CoV-2 binds to angiotensin-converting enzyme 2 (ACE2) for entering into the cells, the researchers have screened different components of tulsi leaf based on inhibition of such binding.
"Interestingly, eugenol, but not other major constituents (e.g. ursolic acid, oleanolic acid and β-caryophylline), of tulsi leaf inhibits the interaction between ACE2 and viral spike S1," said Dr. Pahan. Eugenol also effectively prevents viral entry into human cells.
A good COVID-19 drug should not bind and inhibit ACE2 as it is a beneficial molecule. "It is nice to see that eugenol binds to spike S1, not ACE2," said Dr. Pahan.
Moreover, researchers have demonstrated that after oral treatment, eugenol reduces fever, decreases lung inflammation, normalizes heart function, and enhances locomotor activities in a mouse model of COVID-19.
In addition to tulsi, eugenol is naturally available in clove, ginger, celery, etc. "Therefore, oral eugenol could be a safer approach than available options to prevent SARS-CoV-2 infection and protect COVID-19 patients from various complications," said Dr. Pahan.
Now, eugenol is under clinical development and Dr. Pahan hopes his team's new treatment will control infection in people who haven't been vaccinated and that it will be useful in the event a new strain of the virus emerges that eludes vaccines' protection.
Pahan Lab is a research laboratory at the Rush University Medical Center.
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