Extracts from two common wild plants have been found to inhibit SARS-CoV-2, the virus that causes Covid-19, according to a study published in the journal Scientific Reports.
The plants are the tall goldenrod (Solidago altissima) and the eagle fern (Pteridium aquilinum), which are common in various parts of the world. The extracts that could inhibit SARS-Cov-2 were found in the flowers of the tall goldenrod (Solidago altissima) and the rhizomes of the eagle fern.
Although both plants are common, the researchers have advised people not to treat themselves with these extracts. This could be potentially dangerous, because the eagle fern is known to be toxic. Self-treatment could also be ineffective, because the compounds that block the virus are present in extremely small quantities in the plants.
Researchers from Emory University conducted laboratory dish tests on these extracts. They found that the flowers of the tall goldenrod and the rhizomes of the eagle fern both blocked SARS-CoV-2 from entering human cells, separately.
“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 have isolated the active ingredients, we plan to further test for their safety and for their long-range potential as medicines against Covid-19,” a press release from Emory University quoted the study’s senior author, Cassandra Quave, as saying.
SARS-CoV-2 is known to infect people by using its spike protein, which binds to a protein called ACE2 that the host has on their cells. In their experiments, the researchers used virus-like particles from SARS-CoV-2, and cells that were programmed to overexpress ACE2 on their surface. If a virus-like protein bound to an ACE2 protein entered a cell, the experiment would activate a fluorescent green protein.
A plant extract was added to the cells in a petri dish. Scientists now examined whether the viral particles had entered the cells and activated the green protein. They observed that the extracts from tall goldenrod and eagle fern showed the strongest activity protecting against entry of the virus.