Algae Polysaccharides (Carrageenan and Alginate)—A Treasure-Trove of Antiviral Compounds: An In Silico Approach to Identify Potential Candidates for Inhibition of S1-RBD Spike Protein of SARS-CoV2

Abstract

For the last three years, the world has faced the unexpected spread of the pandemic of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The high mortality rate and ever-changing shape of the virus are the challenging factors in the effective management of SARS-CoV-2. However, in last three years, research communities have made significant progress in developing vaccines and controlling the spread of the pandemic to a certain extent. These vaccines contain the attenuated pathogens, which after application did not kill the virus but protected the human by enhancing the immune system response during pandemic exposure. However, the negative side effects and the high cost of the synthetic vaccines are always of concern for researchers, consumers, and the government. Therefore, as an alternative to synthetic drugs, natural medicines or natural plant products have piqued researchers’ interest. Algae are considered as a treasure house of bioactive compounds such as carotenoids, vitamins, polysaccharides, proteins, etc. These bioactive compounds have been well documented for the treatments of various human ailments such as cancer and cardiovascular diseases. Furthermore, sulfated polysaccharides such as alginate and carrageenan have been reported as having antiviral and immunomodulating properties. Therefore, this review addresses algal polysaccharides, especially alginate and carrageenan, and their application in the treatment of COVID-19. In addition, in silico approaches are discussed for the inhibition of the S1-RBD (receptor-binding domain) of SARS-CoV-2, which attaches to the host receptor ACE2 (angiotensin-converting enzyme 2), and the interaction with the network of relative proteins is also explored, which will help in drug discovery and drug design.