Influenza virus and coronavirus, belonging to enveloped RNA viruses, are major causes of human respiratory diseases. The aim of this study was to investigate the broad spectrum antiviral activity of a naturally existing sulfated polysaccharide, lambda-carrageenan (λ-CGN), purified from marine red algae. Cell culture-based assays revealed that the macromolecule efficiently inhibited both influenza A and B viruses with EC 50 values ranging from 0.3 to 1.4 μg/ml, as well as currently circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an EC 50 value of 0.9 ± 1.1 μg/ml. No toxicity to the host cells was observed at concentrations up to 300 μg/ml. Plaque titration and western blot analysis verified that λ-CGN reduced expression of viral proteins in cell lysates and suppressed progeny virus production in culture supernatants in a dose-dependent manner. This polyanionic compound exerts antiviral activity by targeting viral attachment to cell surface receptors and preventing virus entry. Moreover, its intranasal administration to mice during influenza A viral challenge not only alleviated infection-mediated reductions in body weight but also protected 60% of mice from virus-induced mortality. Thus, λ-CGN could be a promising antiviral agent for preventing infection with several respiratory viruses.
【저자키워드】 Microbiology, Drug discovery, 【초록키워드】 viruses, SARS-CoV-2, coronavirus, Mortality, Antiviral, Influenza, body weight, Toxicity, Influenza virus, Viral proteins, antiviral activity, severe acute respiratory syndrome Coronavirus, virus, influenza A, respiratory diseases, respiratory viruses, Viral, mice, western blot, RNA viruses, Cell culture, virus entry, lambda-carrageenan, polysaccharide, respiratory, antiviral agent, expression, intranasal, broad spectrum, administration, Concentration, viral challenge, host cells, cell surface receptor, host cell, cell surface receptors, acute respiratory syndrome, Viral protein, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, dose-dependent manner, culture supernatant, circulating, Western blot analysis, plaque, progeny, virus production, cell lysates, culture supernatants, enveloped RNA viruses, macromolecule, Plaque titration, inhibited, reduced, cause, reductions in, suppressed, purified, cell lysate, preventing infection, sulfated, 【제목키워드】 coronavirus, Influenza virus, antiviral activity, respiratory, acute respiratory syndrome,