**Natalia Besednova 1, Tatiana Zaporozhets 1, Tatiana Kuznetsova 1, Ilona Makarenkova 1, Lydmila Fedyanina 2, Sergey Kryzhanovsky 2, Olesya Malyarenko <sup>3</sup> and Svetlana Ermakova 3,\***


Received: 15 May 2019; Accepted: 20 June 2019; Published: 22 June 2019

**Abstract:** Context: Seaweed metabolites (fucoidans, carrageenans, ulvans, lectins, and polyphenols) are biologically active compounds that target proteins or genes of the influenza virus and host components that are necessary for replication and reproduction of the virus. Objective: This review gathers the information available in the literature regarding to the useful properties of seaweeds metabolites as potential agents for the prevention and therapy of influenza infection. Materials and methods: The sources of scientific literature were found in various electronic databases (i.e., PubMed, Web of Science, and ScienceDirect) and library search. The retrospective search depth is 25 years. Results: Influenza is a serious medical and social problem for humanity. Recently developed drugs are quite effective against currently circulating influenza virus strains, but their use can lead to the selection of resistant viral strains. In this regard, new therapeutic approaches and drugs with a broad spectrum of activity are needed. Metabolites of seaweeds fulfill these requirements. This review presents the results of in vitro and in vivo experimental and clinical studies about the effectiveness of these compounds in combating influenza infection and explains the necessity of their use as a potential basis for the creation of new drugs with a broad spectrum of activity.

**Keywords:** Flu; alga; sulphated polysaccharides; alginates; lectins; polyphenols; anti-viral activity
