Antiviral Compounds Based on Natural Astragalus polysaccharides (APS): Research and Foresight in the Strategies for Combating SARS-CoV-2 (COVID-19).

Today, finding natural polymers with desirable properties for use in various industries is one of the critical axes of research in the world. Polysaccharides are a group of natural polymers that have various applications in the pharmaceutical industry. The attachment of monosaccharides forms polysaccharides through glycosidic bonds that are widely found in various sources, including plants. Genus Astragalus belongs to the Fabaceae family. Plants belonging to this genus have different polysaccharides. Astragalus polysaccharides (APS) have attracted a great deal of attention among natural polymers because they are non-toxic, biodegradable, and biocompatible. Currently, APS have great drug potential for curing or treating various diseases. Due to the different biological activities of polysaccharides, including Astragalus, this study has investigated the chemical structure of APS, reporting on the antiviral and anti-inflammatory activities as well as stimulation of cytokine secretion by these polysaccharides. Also, in this study, the pharmaceutical approaches of APS compounds, as a natural, new and inexpensive source, have been discussed as suitable candidates for use in pharmaceutical formulations and preparation of new drugs to control COVID-19 infection.