COVID-19: A Nasal Spray Made From Seaweed Extracts Could Prevent Infection

A recently published research has shown Remdesivir as the current standard in the treatment to combat COVID-19. A clinical trial by Beigel et al. showed that Remdesivir was superior to placebo in shortening the time to recovery in adults who were hospitalized with COVID-19. However, Remdesivir has been shown to have side effects such as liver damage. Therefore, investigation of other possible antivirals is still underway in hopes of providing a better alternative. Recent research published by Kwon and colleagues in the Journal of Cell Discovery is developing strategies to combat viruses such as the novel coronavirus (COVID-19) which has currently been classified as a pandemic.

Seaweed

Mechanism of novel coronavirus

The spike protein on the surface of SARS-Cov-2 attaches to the ACE-2 receptor – a molecule on the surface of human cells. Subsequently, the virus injects its genetic material into the host cell and reproduces. On the other hand, there is a chance that the virus can instead latch onto a decoy molecule that has an analogous look. This technique can neutralize the virus which can then get degraded by macrophages. Prior research on other viruses has demonstrated paramount success using the decoy technique.

Professor Jonathan Dordick stated that understanding the mechanism of how to prevent a viral infection can be the stepping stone to the combat of pandemics and other global health concerns. He then added that we currently do not have a wide range of antiviral therapeutics. Therefore, in order to combat pandemics, we will need novel strategies that can quickly target viruses.

Research On Seaweed Extract As Nasal Spray

Kwon et al. examined the activity of three versions of heparin and two fucoidans all extracted from a type of edible seaweed. The five compounds are sulfated polysaccharides which have proven to be an effective trap.

A dose-response study was performed and the effective concentration of the compound that produces a half-maximal response (EC50) was measured in molar concentration with each of the above five compounds. A lower EC50 is an indication of higher potency compared to a higher EC50. A variant of fucoidans, RPI-27, had an EC50 value of 83 nanomolar while another study in mammalian cells showed an EC50 of 770 nanomolar in Remdesivir. Heparin had lower EC50 compared to its variant non-anticoagulant analog of heparin, 2.1 micromolar, and 5.0 micromolar respectively. After testing at high concentrations no cellular toxicity was observed.

Professor Robert Linhardt stated that seaweed extract can be the basis of a nasal spray since COVID-19 infections start at the nose. In addition, Professor Linhard stated that if the infection is treated early or before it occurs then there is a great chance of preventing the infection before it begins attacking the immune system. Professor Dordick also indicated that seaweed extract can play a role in oral administration to address gastrointestinal effects.

Professors Dordick and Linhardt recognized that based on the SARS-CoV2-sequence the domains on the structure of the protein binded with heparin. The protein is coated in glycans which protects it from degradation against human enzymes and allows it to bind to the receptor on the surface.

Professor Dordick that it is a complex issue that still requires further investigation. He also added that the larger sulfated polysaccharides are more successful at the decoy technique due to the larger number of sites available for the virus to bind to.

Professors Dordick and Linhard continue to research novel strategies to combat the novel coronavirus.