The possibility of obtaining these natural compounds in large amounts from different algae converts the extraction and depolymerization processes in key aspects, affecting the structure and activity. Chen and co-authors reviewed the antiviral properties, mechanisms, and applications of some polysaccharides as therapeutic agents and vaccine adjuvants for the treatment of coronavirus. The COVID-19 pandemic, caused by the SARS-CoV-2 virus, caused some researchers to reconsider the potential of algal metabolites, particularly from seaweeds. Cheong and co-authors published a new perspective on the potential applications of carrageenan oligomers in the functional food and pharmaceutical industry with an emphasis on the production, purification, analysis, characterization, and biological properties. Lee presented a complete overview of the potential of carrageenans as preventive microbicides, based on in vitro, in vivo, and ex vivo assays of activity and safety. The dietary and pharmaceutical applications of polysaccharides in the prevention and treatment of viral diseases and the marine glycan-based antiviral drugs undergoing preclinical and clinical trials have been recently reviewed.
Pagarete and coworkers presented a survey on algal antivirals. 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). Ngo and Kim focused on sulfate polysaccharides derived from marine algae and presented an overview of their biological activities, including antiviral. ĭifferent authors have reviewed the antiviral activities of marine-derived polysaccharides, low-molecular-weight fractions and derivatives, and their underlying mechanisms of action and medical applications.
Therefore, carrageenan and its depolymerized products, oligosaccharides, are considered a good alternative for the prevention of a wide range of diseases, mainly caused by enveloped viruses. Despite having good inhibitory effects on virus replication, the high-molecular-weight (MW)-associated poor tissue-penetrating ability of sulfated polysaccharides limits their potential antiviral application in humans. The biological activity of these high-molecular-weight compounds is determined by their chemical structure including the degree of sulfation, molecular weight, constituent sugars, and their stereochemistry. In addition to the various biological activities such as anti-thrombotic, antiviral, anticancer, and immunomodulatory properties, carrageenan can be used to prepare microdimensional-based structures, useful for easy and controlled drug administration. Carrageenans are approved as food grade additives and are used as thickeners and emulsifiers. Sulfated galactans are the main matrix polysaccharide, found as agar or as carrageenan. Red seaweed polysaccharides contain different sulfated galactans, sulfated mannans, carrageenans, and agars, which are active against a wide range of viruses.
In addition, several sulfated seaweed polysaccharides were found as immunomodulators and can be used as vaccine adjuvants in nanomaterials and drug delivery systems. The structural diversity and complexity of seaweed polysaccharides and their derivatives contribute to their activity in different phases of viral infection processes. Seaweeds are attractive candidates for developing potential antivirals due to their relatively high content of sulfated polysaccharides, low production costs, and wide availability they are biodegradable, biocompatible, safe, and non-toxic. Recent research on the strong antiviral activity of polysaccharides, particularly against enveloped viruses, can be found. Although highly sulfated synthetic glycomimetics are effective inhibitors of viral infection both in vitro and in vivo, natural polysaccharides from renewable sources offer advantages in relation to their low cost, absence of toxicity and side effects, wide spectrum of activity, and low induction of resistance. Sulfated polysaccharides mimicking the heparan sulfate are potential antivirals that can interfere with the early stages of viral replication, including the virus entry, by masking the positive charge of the virus surface receptors to prevent them from binding to the heparan sulfate proteoglycans in the host cell surface. Novel antivirals are demanded to fight against viral infections with no available treatment but also to overcome certain problems associated with the use of some current drugs, such as unsatisfactory efficacy, adverse effects, toxicity, viral resistance, and high cost.
0 kommentar(er)
