The plants are tall goldenrod (Solidago altissima) and eagle fern (Pteridium aquilinum), both of which are common throughout the world. SARS-Cov-2 inhibitory extracts were discovered in the flowers of the tall goldenrod (Solidago altissima) and the rhizomes of the eagle fern.
Despite the fact that both plants are common, the researchers advise people not to use the extracts to treat themselves. Because the eagle fern is known to be toxic, this could be dangerous.
Self-treatment may also be ineffective because the compounds that inhibit the virus are present in minute amounts in the plants.
Emory University researchers tested these extracts in laboratory dishes. They discovered that the flowers of tall goldenrod and the rhizomes of eagle fern both prevented SARS-CoV-2 from entering human cells.
"It's very early in the process, but we're working to identify, isolate and scale up the molecules from the extracts that showed activity against the virus. Once we've isolated the active ingredients, we plan to test them for safety and long-term potential as medicines against Covid-19," the study's senior author, Cassandra Quave said.
SARS-CoV-2 is known to infect people by using its spike protein, which binds to a protein on the host's cells called ACE2. The researchers used virus-like particles from SARS-CoV-2 in their experiments, as well as cells programmed to overexpress ACE2 on their surface. The experiment would activate a fluorescent green protein if a virus-like protein bound to an ACE2 protein entered a cell.
In a petri dish, cells were treated with a plant extract. The researchers now wanted to know if the viral particles had entered the cells and activated the green protein. They discovered that extracts from tall goldenrod and eagle fern had the greatest activity in preventing virus entry.