An extract from seaweed has outperformed Remdesivir in ousting COVID-19 during cellular tests, according to new research.
The research is part of a larger body of research investigating a 'decoy strategy' against viruses such as COVID-19. This strategy works by urging the virus to 'latch' onto decoys rather than healthy human cells, where it then becomes trapped, neutralized and eventually destroyed.
In the case of COVID-19, the spike protein on the surface of SARS-CoV-2 attaches onto a molecule on the surface of human cells known as the ACE_2 receptor. Once attached, it then inserts its own genetic material inside the cell so it can begin to replicate. Usage of the right decoy would mean that SARS-CoV-2 may be 'distracted' away from human cells and, instead of being able to replicate and cause havoc in the human body, be destroyed. Previous findings have shown thta the strategy works in ousting other viruses like Dengue, Zika and Influenza A.
For the present findings, researchers from the Center for Biotechnology and Interdisciplinary Studies (CBIS) at Rensselaer Polytechnic Institute tested antiviral activity in five compounds. These were three variants of heparin (a common blood thinner) and two fucoidans, extracted from seaweed. All five compounds are long chains of sugar molecules.
The researchers conducted a dose-response study known as an EC50 with each of the compounds against SARS-CoV-2 in mammalian cells. In the end, they found that seaweed extract RPI-27 had significantly better antiviral effects than Remdesivir. While Remdesivir has an EC50 value of 770 nanomolar, RPI-27 had an EC50 value of around 83 nanomolar (the lower the value, the better).
"What interests us is a new way of getting at infection," says Professor Robert Linhardt, one of the study's authors. "The current thinking is that the COVID-19 infection starts in the nose, and either of these substances could be the basis for a nasal spray. If you could simply treat the infection early, or even treat before you have the infection, you would have a way of blocking it before it enters the body."