Extracts from two wild plants inhibit COVID-19 virus

summary: Extracts from two common wildflowers, the tall goldenrod and wasishida, blocked SARS_CoV_2, the virus that causes COVID-19, from entering human cells. Researchers have warned the public that the plant should not be consumed as a means of self-treatment against coronavirus as it may be toxic. may provide new avenues for

sauce: Emory University

Two common wild plants contain extracts that block the ability of the virus that causes COVID-19 to infect living cells, according to Emory University research.

scientific report This is the first major screening of plant extracts for efficacy against the SARS-CoV-2 virus.

In a laboratory dish test, extracts from tall goldenrod (Solidago altissima) flowers and eagle fern (Pteridium aquilinum) rhizomes each blocked SARS-CoV-2 from entering human cells.

The active compound is present in plants in only trace amounts. Researchers stress that it is ineffective and potentially dangerous for people to try to treat themselves with them. I am warning you.

“Although we are very early in the process, we are working to identify, isolate and scale up molecules from the extract that have shown activity against the virus,” said senior author of the study and associate at Emory School of Medicine. Professor Cassandra Quabe said: Dermatology and Human Health Research Center.

“Once we isolate the active ingredient, we plan to further test its safety and long-term potential as a drug against COVID-19.”

Quave is an ethnobotanist who studies how plants have been used medicinally by traditional peoples and identifies promising new candidates for modern medicine. Her lab maintains the Quave Natural Product Library, which contains thousands of plant and fungal natural products extracted from plants collected at sites around the world.

Caitlin Risener, Ph.D. Candidate for Emory’s Graduate Program in Molecular Systems Pharmacology and the Center for Human Health Research, is the current lead author of the paper.

In previous work to identify potential molecules for the treatment of drug-resistant infections, the Quave lab focused on plants traditionally used by people to treat skin inflammation. I got

Given that COVID-19 is an emerging disease, researchers took a broader approach. They devised a method to rapidly test over 1,800 extracts and 18 compounds from the Quave Natural Product Library for activity against SARS-CoV-2.

“We have shown that our natural product library is a powerful tool to help search for potential treatments for emerging diseases,” says Risener. “Other researchers can adapt our screening method to search for other novel compounds within plants and fungi that may lead to new drugs to treat various pathogens. ”

SARS-CoV-2 is an RNA virus with a spike protein that can bind to a protein called ACE2 on host cells. “The viral spike protein uses the ACE2 protein like a key to allow the virus to enter and infect cells,” explains Quave.

Researchers devised an experiment using SARS-CoV-2 virus-like particles (VLPs) and cells programmed to overexpress ACE2 on their surface. VLPs had stripped away the genetic information necessary to cause COVID-19 infection. Instead, when the VLPs bound to her ACE2 protein and entered the cell, they were programmed to hijack the cellular machinery and activate the fluorescent green protein.

Plant extracts were added to the cells in Petri dishes prior to the introduction of viral particles. By shining a fluorescent light on the dish, we were able to quickly determine whether the virus particles had entered the cells and activated the green proteins.

The researchers identified several extracts that prevented viral entry and focused on those that showed the strongest activity. Both plant species are native to North America and are known for their traditional medicinal use by Native Americans.

Additional experiments showed that the protective power of the plant extract works across four variants of SARS-CoV-2 (alpha, theta, delta and gamma).

To further test these results, the Quave lab, co-author, Emory Professor of Pediatrics, director of Emory’s Laboratory of Biochemistry and Pharmacology, and an HIV researcher within the NIH-sponsored Emory University Center. We collaborated with Raymond Skinazi, co-director of the Therapeutic Science Working Group. For AIDS research. A world leader in antiviral drug development, Skinazi is best known for his groundbreaking pioneering work on HIV drugs.

The Skinazi Institute’s higher biosecurity rating allowed researchers to test the two plant extracts in experiments using the infectious SARS-CoV-2 virus instead of VLPs. The results confirmed the ability of tall goldenrod and eagle fern extracts to inhibit the ability of SARS-CoV-2 to bind to and infect living cells.

“Our results lay the groundwork for the future use of natural product libraries to find new tools and treatments for infectious diseases,” says Quave.

As a next step, researchers are working to determine the exact mechanism that enables the two plant extracts to block binding to the ACE2 protein.

For Risener, one of the best things about this project is that she herself collected samples of tall goldenrods and eagle ferns. In addition to collecting medicinal plants from around the world, the Quave lab also conducts field trips to the Joseph W. Jones Research Center in South Her Georgia.

The Woodruff Foundation established the Center to conserve one of the last remnants of the unique longleaf pine ecosystem that once dominated the southeastern United States.

“It’s great to step into nature to identify and dig up plants,” says Risener. “This is very little a pharmacology grad student can do. Head-to-toe covered in dirt, kneeling on the ground, glowing with excitement and euphoria.”

She also assists in preparing plant extracts and mounting specimens for the Emory Herbarium.

“Collecting the specimens yourself, drying and preserving them creates a personal connection,” she says. “It’s not like being handed a vial of plant material in a lab and told, ‘Please analyze this,'” she said.

After graduation, Risener hopes to pursue a career in science policy outreach and teaching surrounding the study of natural compounds. Some of the more well-known plant-based drugs include aspirin (from willows), penicillin (from fungi), and the cancer drug taxol (from yew trees).

“Plants have such complex chemistry that it is probably impossible for humans to imagine all the plant compounds waiting to be discovered,” says Risener. “The vast medicinal benefits of plants highlight the importance of protecting ecosystems.”

About this pharmacology and COVID-19 research news

author: Carroll Clark
sauce: Emory University
contact: Carol Clark – Emory University
image: image is public domain

Original research: open access.
“Plant inhibitors of SARS-CoV-2 virus entry: a phylogenetic perspective” Caitlin J. Risener et al. scientific report

---

overview

Plant inhibitors of SARS-CoV-2 virus entry: a phylogenetic perspective

The use of botanical supplements increased in the United States during the SARS-CoV-2 pandemic, but their safety and efficacy against COVID-19 have yet to be investigated.

The Quave Natural Product Library is a collection of phylogenetically diverse plant and fungal natural product extracts, including popular supplement ingredients.

Evaluation of 1867 extracts and 18 compounds for viral spike protein binding to host cell ACE2 receptors in a SARS-CoV-2 pseudotyped virus system showing ≥ 50% virus in 76 families (3 fungi, 73 plants) 310 extracts from 188 species spanning across invasion inhibitory activity at 20 μg/mL were identified.

Extracts with greater than 15% mammalian cytotoxicity and extracts containing cardiotoxic cardiac glycosides were excluded.

Three extracts were selected for further testing against four pseudotyped variants and infectious SARS-CoV-2, and were further chemically characterized to show potent (EC₅₀< 5 µg/mL) antiviral activity Solidago is very tall L. (Asteraceae) flowers and pteridium akyrin (L.) Rhizome of Coon (Densteaceae).