Antiviral Potential of Algal Metabolites—A Comprehensive Review

Abstract

Historically, algae have stimulated significant economic interest particularly as a source of fertilizers, feeds, foods and pharmaceutical precursors. However, there is increasing interest in exploiting algal diversity for their antiviral potential. Here, we present an overview of 50-years of scientific and technological developments in the field of algae antivirals. After bibliometric analysis of 999 scientific references, a survey of 16 clinical trials and analysis of 84 patents, it was possible to identify the dominant algae, molecules and viruses that have been shaping and driving this promising field of research. A description of the most promising discoveries is presented according to molecule class. We observed a diverse range of algae and respective molecules displaying significant antiviral effects against an equally diverse range of viruses. Some natural algae molecules, like carrageenan, cyanovirin or griffithsin, are now considered prime reference molecules for their outstanding antiviral capacity. Crucially, while many algae antiviral applications have already reached successful commercialization, the large spectrum of algae antiviral capacities already identified suggests a strong potential for future expansion of this field.

The Potency of Seaweed Sulfated Polysaccharides for the Correction of Hemostasis Disorders in COVID-19

“…As for SARS-CoV and other coronaviruses, they can bind to host cells by clinging through their GAG [ 125 ]. In this regard, numerous works are devoted to the anticoronavirus ability of PSs [ 126 , 127 , 128 ].…”

Seaweed Sulfated Polysaccharides against Respiratory Viral Infections

“…Symptomatic therapies or antiviral medications are still the major tools to treat vRTIs [ 19 ] as vaccines are currently not yet available for most of the respiratory viruses [ 20 ] except against influenza, adenovirus and more recently, against SARS-CoV-2. However, it is also important to notice that such vaccines will face several specific hurdles: (i) they could be restricted to some countries and dedicated personnel, as evidenced by the adenovirus vaccine available only to military personnel in the US; (ii) their mild efficacy (from 30% to 60% for the influenza vaccine) and need for annual revaccination due to emerging new variants [ 6 ] and (iii) high-cost and need for specific cold chain suppliers as observed with recent mRNA vaccines against SARS-CoV-2.…”

“…The search for appropriate antiviral agents is not only limited to synthetic molecules, but other natural alternatives are also in consideration because of some interesting properties, such as biocompatibility, low toxicity, biodegradability and renewable nature [ 35 , 36 ]. In this context, natural products using terrestrial sources (herbal medicine) [ 37 ] or marine origin [ 20 , 36 ] have gained huge interest. The SARS-CoV-2 pandemic has given rise to many investigations of natural products to treat the associated respiratory disease.…”

“…However, despite a considerable amount of research regarding their antiviral potential, mainly demonstrated through in vitro cell culture assays, the practical application of these seaweeds goes unrecognized. Indeed, to date, there has been limited clinical studies that highlight the effectiveness of seaweed SPS as treatment of infected individuals, restricted to iota-carrageenan [ 20 , 85 , 86 , 87 , 88 ] ( Table 1 ), which is the only sulfated seaweed polysaccharide that has been approved by EMA for its use in common cold [ 20 , 84 ]. Thus, despite their promising potential, their use is mainly limited to nutraceuticals and cosmeceuticals [ 90 , 91 ].…”

Antiviral Activity of Carrageenans and Processing Implications

“…Besednova and co-authors reviewed the studies on the potential use of different algal metabolites, including polysaccharides, for the prevention and treatment of human immunodeficiency virus (HIV) [ 16 ]. Pagarete and coworkers [ 30 ] presented a survey on algal antivirals. The dietary and pharmaceutical applications of polysaccharides in the prevention and treatment of viral diseases [ 31 ] and the marine glycan-based antiviral drugs undergoing preclinical and clinical trials [ 2 ] have been recently reviewed.…”