Two compounds isolated from hemp varieties of Cannabis sativa can block the COVID-19 virus from entering human cells, according to a new study led by Oregon State University researchers.
The researchers said the compounds “have the potential to prevent as well as treat infection” by COVID-19, “as a complement to vaccines.”
The study, published on Monday in the Journal of Natural Products, found that cannabigerolic acid, or CBGA, and cannabidiolic acid, or CBDA, bind to the spike proteins on the surface of the coronavirus. The virus depends on the spike proteins to gain access to cells, making the proteins a drug target for vaccines and existing antiviral treatments including monoclonal antibodies.
“These cannabinoid acids are abundant in hemp and in many hemp extracts,” lead researcher Richard van Breemen of Oregon State University’s Global Hemp Innovation Center, College of Pharmacy, and Linus Pauling Institute said in a university release. “They are not controlled substances like THC, the psychoactive ingredient in marijuana, and have a good safety profile in humans.”
CBGA and CBDA are the chemical precursors of cannabigerol, or CBG, and cannabidiol, or CBD, which are popular as supplements in food and cosmetics. However, the study found CBD and CBG were much less effective at binding to the coronavirus spike protein.
Researchers tested the effectiveness of CBGA and CBDA in the lab using live coronavirus strains, including the alpha and beta variants. They found the compounds succeeded at preventing infection in epithelial cells, which line the lungs, heart, blood vessels, intestines and kidneys.
“Cell entry inhibitors, like the acids from hemp, could be used to prevent SARS-CoV-2 infection and also to shorten infections by preventing virus particles from infecting human cells,” said van Bremen.
Because COVID variants of concern, including alpha and beta, have undergone “rapid mutations” in their spike proteins, they can evade antibodies and reduce the effectiveness of vaccines designed using older strains of COVID, he said.
Omicron contains dozens of mutations on the spike protein that have allowed it to better evade immunity from past infections, made it more resistant to vaccines, and reduced the potency of two leading monoclonal antiviral therapies.
But using drugs derived from CBDA and CBGA alongside vaccination would make it more challenging for COVID variants to escape from immunity, said van Bremen.
“Our data show CBDA and CBGA are effective against the two variants we looked at, and we hope that trend will extend to other existing and future variants,” he said.
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