Prevention of human enterovirus 71 infection by kappa carrageenan

Enterovirus 71 (EV 71), the newest member of Enteroviridae, is notorious for its etiological role in epidemics of the hand-foot-and-mouth disease, particularly in association with fatal neurological complications in young children. Searching for new and more effective agents against EV 71 infections has never relented as corresponding vaccines or antiviral drugs remain unavailable. Sulfated polysaccharides from seaweed are known to possess a broad range of biological activities across anti-virus, anti-tumor, immunomodulation, anti-coagulation, etc. In this study, we report kappa carrageenan also has a strong and effective anti-EV 71 activity able to reduce plaque formation, prevent viral replication before or during viral adsorption, as well as inhibit EV 71-induced apoptosis. In virus binding assay, kappa carrageenan was shown able to bind EV 71 firmly, forming carrageenan-viruses complexes, whereby the virus-receptor interaction is likely disrupted. Added together, kappa carrageenan may be an ideal candidate worthwhile to develop into anti-EV 71 agents.