Researchers at Oregon State University say that chemical compounds found in hemp can block the virus that causes COVID-19 from entering human cells.
Those findings come from a study published Monday in the Journal of Natural Products, authored by Richard van Breemen, a scientist with Oregon State’s Global Hemp Innovation Center, College of Pharmacy and Linus Pauling Institute.
Van Breeman said that hemp, known by its scientific name as Cannabis sativa, contains a pair of cannabinoid acids that bind to the SARS-CoV-2 spike protein, preventing the virus from infecting people. With the help of his colleagues, van Breeman discovered that two acids, cannabigerolic acid, or CBGA, and cannabidiolic acid, CBDA, target the same spike protein that COVID-19 vaccines and antibody therapy target to prevent and treat the disease.
“These cannabinoid acids are abundant in hemp and in many hemp extracts,” van Breemen said. “They are not controlled substances like THC, the psychoactive ingredient in marijuana, and have a good safety profile in humans. And our research showed the hemp compounds were equally effective against variants of SARS-CoV-2, including variant B.1.1.7, which was first detected in the United Kingdom, and variant B.1.351, first detected in South Africa.”
According to OSU, the variants van Breeman referred to are the alpha and beta variants of COVID-19, respectively.
Van Breeman explained that the SARS-CoV-2 virus has crown-like protrusions on its outer surface, RNA strands that encode its four main structural proteins — spike, envelope, membrane, and nucleocapsid — as well as 16 nonstructural proteins and several "accessory proteins," according to OSU.
“Any part of the infection and replication cycle is a potential target for antiviral intervention, and the connection of the spike protein’s receptor binding domain to the human cell surface receptor ACE2 is a critical step in that cycle,” he said. “That means 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. They bind to the spike proteins so those proteins can’t bind to the ACE2 enzyme, which is abundant on the outer membrane of endothelial cells in the lungs and other organs.”
He observed that compounds that block virus-receptor interaction have been used in treatments for other viral infections, including HIV-1 and hepatitis, and could similarly be used to treat COVID-19.
The scientific team at OSU used a mass spectrometry-based screening technique invented in van Breeman's laboratory to discover the compounds. They screened a range of botanical compounds used as a dietary supplement including red clover, wild yam, hops, and three species of licorice, OSU said.
Hemp is a source of fiber, food, and animal feed. Multiple hemp extracts and compounds are used in cosmetics, body lotions, dietary supplements, and food.
“These compounds can be taken orally and have a long history of safe use in humans,” van Breemen said. “They have the potential to prevent as well as treat infection by SARS-CoV-2. CBDA and CBGA are produced by the hemp plant as precursors to CBD and CBG, which are familiar to many consumers. However, they are different from the acids and are not contained in hemp products.”