Emory University researchers have discovered that the COVID-19 virus cannot infect live cells when exposed to extracts from two common wild plants. These results, which were published in Scientific Reports, are the first systematic search for antiviral efficacy in plant extracts against SARS-CoV-2.
In laboratory dish trials, extracts of the flowers of tall goldenrod (Solidago altissima) and the rhizomes of eagle fern (Pteridium aquilinum) both blocked the entry of SARS-CoV-2 into human cells. A small quantity of the active compounds are found in the plant structures. It has been determined by the specialists that any individual who attempts to treat oneself with these chemicals is doing so at his or her own peril. The eagle fern is a recognized toxic plant, as the warnings state.
Despite the fact that it is very early in the process, researchers are attempting to identify, isolate, and scale up the compounds from the extracts that demonstrated effectiveness against the virus, as stated by the study’s senior author, Cassandra Quave. Despite the fact that this is still extremely early in the process, work is being done on it.
For his work as an ethnobotanist, Quave investigates the historical therapeutic uses of plants by indigenous peoples in order to identify novel drug possibilities. Her lab is in charge of the Quave Natural Product Library, a collection of thousands of plant and fungal product isolates from all around the world.
As a technique of discovering potential chemicals for use in the treatment of drug-resistant bacterial infections, the Quave lab previously focused on plants that traditional people had utilized to alleviate skin irritation. This action was taken because numerous bacterial illnesses had grown resistant to existing medicines and new therapies were needed.
Given the condition’s relative novelty, the researchers opted for a more all-encompassing methodology. They developed a method to rapidly test the effectiveness of more than 1,800 extracts and 18 compounds from the Quave Natural Product Library against SARS-CoV-2.
Researchers conducted experiments using SARS-CoV-2 virus-like particles (VLPs) and cells engineered to overexpress ACE2 on their surface. Before testing the VLPs, the genetic information required to cause a COVID-19 infection was deleted. Instead, a virus-like particle (VLP) was built to take over the machinery within a cell and activate a brilliant green protein if it bound to an ACE2 protein and entered a cell.
On order to prepare the cells in a petri dish for the entry of the virus particles, they were treated with a plant extract. Putting a fluorescent light over the plate revealed whether the virus particles had entered the cells and triggered the green protein, providing a quick response to the researchers’ inquiry.
After finding many promising plant extracts that blocked the virus’ entry, the researchers zeroed down on two particularly active ones: tall goldenrod and eagle fern. Both plants are native to North America and have long histories of medicinal usage among indigenous peoples.
Additional testing revealed that the plant extracts’ protective effects held true against the four subtypes of SARS-CoV-2 (alpha, theta, delta, and gamma).
Professor of Pediatrics Raymond Schinazi is also the Director of the Division of Laboratory of Biochemical Pharmacology at Emory University and a Co-Director of the HIV Cure Scientific Working Group at Emory’s NIH-Funded Center for AIDS Research (NIH). With Schinazi’s help, the Quave lab was able to put these findings through further testing. In the field of antiviral therapy, he is considered a world leader due to his groundbreaking work on new HIV drugs.
The two plant extracts were tested using infectious SARS-CoV-2 virus rather than VLPs since the Schinazi laboratory had a higher biosecurity grade than the other laboratories. The results demonstrated that eagle fern and tall goldenrod extracts inhibited SARS-ability CoV-2’s to infect living cells by binding to them.
The next step for the researchers is to zero in on the precise mechanism through which the two plant extracts block ACE2 protein binding. The unique longleaf pine ecosystem, formerly widespread over the southern portion of the United States, is now only represented by a few of remnants, and the Woodruff Foundation built the facility to help with their preservation.
