Cyanometabolites: molecules with immense antiviral potential.

Cyanometabolites are active compounds derived from cyanobacteria that include small low molecular weight peptides, oligosaccharides, lectins, phenols, fatty acids, and alkaloids. Some of these compounds may pose a threat to human and environment. However, majority of them are known to have various health benefits with antiviral properties against pathogenic viruses including Human immunodeficiency virus (HIV), Ebola virus (EBOV), Herpes simplex virus (HSV), Influenza A virus (IAV) etc. Cyanometabolites classified as lectins include scytovirin (SVN), Oscillatoria agardhii agglutinin (OAAH), cyanovirin-N (CV-N), Microcystis viridis lectin (MVL), and microvirin (MVN) also possess a potent antiviral activity against viral diseases with unique properties to recognize different viral epitopes. Studies showed that a small linear peptide, microginin FR1, isolated from a water bloom of Microcystis species, inhibits angiotensin-converting enzyme (ACE), making it useful for the treatment of coronavirus disease 2019 (COVID-19). Our review provides an overview of the antiviral properties of cyanobacteria from the late 90s till now and emphasizes the significance of their metabolites in combating viral diseases, particularly severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has received limited attention in previous publications. The enormous medicinal potential of cyanobacteria is also emphasized in this review, which justifies their use as a dietary supplement to fend off pandemics in future.