Sulphated Polysaccharides from Ulva clathrata and Cladosiphon okamuranus Seaweeds both Inhibit Viral Attachment/Entry and Cell-Cell Fusion, in NDV Infection

Abstract

Sulphated polysaccharides (SP) extracted from seaweeds have antiviral properties and are much less cytotoxic than conventional drugs, but little is known about their mode of action. Combination antiviral chemotherapy may offer advantages over single agent therapy, increasing efficiency, potency and delaying the emergence of resistant virus. The paramyxoviridae family includes pathogens causing morbidity and mortality worldwide in humans and animals, such as the Newcastle Disease Virus (NDV) in poultry. This study aims at determining the antiviral activity and mechanism of action in vitro of an ulvan (SP from the green seaweed Ulva clathrata), and of its mixture with a fucoidan (SP from Cladosiphon okamuranus), against La Sota NDV strain. The ulvan antiviral activity was tested using syncytia formation, exhibiting an IC50 of 0.1 μg/mL; ulvan had a better anti cell-cell spread effect than that previously shown for fucoidan, and inhibited cell-cell fusion via a direct effect on the F0 protein, but did not show any virucidal effect. The mixture of ulvan and fucoidan showed a greater anti-spread effect than SPs alone, but ulvan antagonizes the effect of fucoidan on the viral attachment/entry. Both SPs may be promising antivirals against paramyxovirus infection but their mixture has no clear synergistic advantage.

Marine Algal Antioxidants as Potential Vectors for Controlling Viral Diseases

“…Fucoidans exert their antiviral activities by blocking the interaction of viruses with the cells, thus inhibiting viral-induced syncytium formation [82]. This property led to attachment of fucoidan to the F0 protein resulting in a great antiviral potency of fucoidan, e.g., higher than the antiviral drug ribavirin [83]. Last but not least, fucoidans also display bioactivity on the immune system at cellular and humoral level by increasing macrophage phagocytosis [84].…”

Antiviral and Cytotoxic Activities of Polysaccharides Extracted from Four Tropical Seaweed Species

“…On the other hand, Ulvans are found in green seaweeds of the order Ulvales, and some species of the genus Ulva sp. have shown antiviral activities [18,19].…”

Can Fucoidan Decrease the Mortalities Caused by Columnaris Disease in Nile Tilapia?

“…Therefore, this study demonstrated apparent anti-bacterial and cutaneous wound healing effects of fucoidan. Fucoidan is known for its anti-bacterial, anti-viral, immunostimulatory, and healing stimulating effects [2][3][4][5][6][7][8][9][10][11]. In a previous study, fucoidan inhibited the growth of Staphylococcus aureus and Escherichia coli [5].…”

“…tangleweed (Lami-naria japonica), wakame (Undaria pinnati da Sporophyll) and limu moui (Cladosiphon okamuranus) [1]. Fucoidan is known for its anti-bacterial, anti-viral, immunostimulatory, and healing stimulating effects [2][3][4][5][6][7][8][9][10][11].…”