Antiviral activity of lambda-carrageenan against influenza viruses and severe acute respiratory syndrome coronavirus 2.

ABSTRACT: 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 (?-CGN), purified from marine red algae. Cell culture-based assays revealed that the macromolecule efficiently inhibited both influenza A and B viruses with EC₅₀ values ranging from 0.3 to 1.4 ?g/ml, as well as currently circulating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an EC₅₀ value of 0.9?±?1.1 ?g/ml. No toxicity to the host cells was observed at concentrations up to 300 ?g/ml. Plaque titration and western blot analysis verified that ?-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, ?-CGN could be a promising antiviral agent for preventing infection with several respiratory viruses.

SUBMITTER: Jang Y 

PROVIDER: S-EPMC7804421 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature