Evaluation of Antiviral Effect against SARS-CoV-2 Propagation by Crude Polysaccharides from Seaweed and Abalone Viscera In Vitro

Abstract

Crude polysaccharides, extracted from two seaweed species (Hizikia fusiforme and Sargassum horneri) and Haliotis discus hannai (abalone) viscera, were evaluated for their inhibitory effect against SARS-CoV-2 propagation. Plaque titration revealed that these crude polysaccharides efficiently inhibited SARS-CoV-2 propagation with IC50 values ranging from 0.35 to 4.37 μg/mL. The crude polysaccharide of H. fusiforme showed the strongest antiviral effect, with IC50 of 0.35 μg/mL, followed by S. horneri and abalone viscera with IC50 of 0.56 and 4.37 μg/mL, respectively. In addition, immunofluorescence assay, western blot, and quantitative RT-PCR analysis verified that these polysaccharides could inhibit SARS-CoV-2 replication. In Vero E6 cells, treatment with these crude polysaccharides before or after viral infection strongly inhibited the expression level of SARS-CoV-2 spikes, nucleocapsid proteins, and RNA copies of RNA-dependent RNA-polymerase and nucleocapsid. These results show that these crude marine polysaccharides effectively inhibit SARS-CoV-2 propagation by interference with viral entry.

Bioactivities of the Popular Edible Brown Seaweed Sargassum fusiforme: A Review

“…The results of plaque titration showed that these crude polysaccharides effectively inhibited the spread of SARS-COV-2. 136 Among them, S. f usiforme crude polysaccharides has the strongest antivirus effect. Moreover, treatment of crude polysaccharides can strongly inhibit the expression levels of SARS-COV-2 spike, nucleocapsid protein, and RNA polymerase in the Vero cells model.…”

“…Kang et al evaluated the inhibitory effect of the crude polysaccharides extracted from two kinds of algae ( S. fusiforme and S. horneri ) and Haliotis discus hannai viscera on the spread of SARS-COV-2. The results of plaque titration showed that these crude polysaccharides effectively inhibited the spread of SARS-COV-2 . Among them, S. fusiforme crude polysaccharides has the strongest antivirus effect.…”

“…Moreover, treatment of crude polysaccharides can strongly inhibit the expression levels of SARS-COV-2 spike, nucleocapsid protein, and RNA polymerase in the Vero cells model. 136 Feng et al found that the extract of S. f usiforme has antivirus potential on human adenovirus-7 (HADV-7), and the most effective component is alginate. 137 In addition, they found that the phase in which the adenovirus reacted with alginate after it was added was the most effective phase for antiviral, and its antivirus effect may related to the endoplasmic reticulum stress (ERS) pathway.…”

“…Among them, S. fusiforme crude polysaccharides has the strongest antivirus effect. Moreover, treatment of crude polysaccharides can strongly inhibit the expression levels of SARS-COV-2 spike, nucleocapsid protein, and RNA polymerase in the Vero cells model . Feng et al found that the extract of S. fusiforme has antivirus potential on human adenovirus-7 (HADV-7), and the most effective component is alginate .…”

An integrative approach for compressive quality control of RespireAidTM, a traditional Chinese medicine formula against SARS-CoV-2

“…Polysaccharides from herbal materials are well-known for their immunomodulation effects. Polysaccharides from seaweed were found to inhibit SARS-CoV-2 propagation by blocking viral entry [ 33 ]. Together, these data suggest that different types of carbohydrates could have an important role in the prevention of SARS-CoV-2, beyond the action of just the organic principal components.…”