A edible seaweed extract has been shown to be more effective in inhibiting infection by SARS-CoV-2 in mammalian cells that the remdesivir, the current standard antiviral used to fight disease.

The article, published in “Cell Discovery”, analyzed the antiviral activity of three variants of the anticoagulant heparin (heparin, trisulfated heparin and one non-anticoagulant low molecular weight heparin) and two fucoidans (RPI-27 and RPI-28) extracted from algae. marine. The researchers compared the efficacy of these compounds in laboratory tests versus remdesivir.

The research is the latest example of a decoy strategy that researchers from the Center for Biotechnology and Interdisciplinary Studies (CBIS) of the Rensselear Polytechnic Institute in New York (USA) are developing against viruses such as the new coronavirus.

The spike protein on the surface of SARS-CoV-2 is known to bind to the ACE-2 receptor, a molecule on the surface of human cells. Once anchored, the virus inserts its own genetic material into the cell, hijacking the cellular machinery to produce replica viruses. But, sAccording to the researchers, the virus could easily be ‘tricked’ into binding to a decoy molecule that offers a similar fit. In this way, the neutralized virus would be trapped and eventually degrade naturally.

Previous research has shown that this decoy technique It works to catch other viruses, including dengue, zika, and influenza A.

By treating the infection early, or even before having the infection, the virus would be blocked before it enters the body

“We are learning how to block viral infection; This is the knowledge we will need if we want to quickly deal with other pandemics, “says Jonathan Dordick, the principal investigator. But, he admits, «the reality is that we don’t have great antivirals. To protect ourselves against future pandemics, we will need an arsenal that we can quickly adapt to emerging viruses. “

The researchers conducted a dose-response study known as EC50, short for the effective concentration of the compound that inhibits 50% of viral infectivity, with each of the five compounds in the cells. EC50 results, given in a molar concentration, a lower value indicates a more potent compound.

Of all the compounds, RPI-27 algae extract was the most potent: it produced an EC50 value of about 83 nanomolar, while remdesivir, in previous work, yielded an EC50 of 770 nanomolar.

None of the compounds showed cellular toxicity, even at the highest concentrations tested.

“What we’re interested in is a new way to block the infection,” explains Robert Linhardt. “Covid-19 infection is currently believed to start in the nose and we think that any of these substances could be the basis of a nasal spray. In this way, treating the infection early, or even before having the infection, would block the virus before it enters the body. “

Dordick believes the seaweed compounds “could serve as the basis for oral administration to address possible gastrointestinal infection.”