Plant lectins as prospective antiviral biomolecules in the search for COVID-19 eradication strategies

Abstract

Lectins or clusters of carbohydrate-binding proteins of non-immune origin are distributed chiefly in the Plantae. Lectins have potent anti-infectivity properties for several RNA viruses including SARS-CoV-2. The primary purpose of this review is to review the ability of lectins mediated potential biotherapeutic and bioprophylactic strategy against coronavirus causing COVID-19. Lectins have binding affinity to the glycans of SARS-COV-2 Spike glycoprotein that has N-glycosylation sites. Apart from this, the complement lectin pathway is a “first line host defense” against the viral infection that is activated by mannose-binding lectins. Mannose-binding lectins deficiency in serum influences innate immunity of the host and facilitates infectious diseases including COVID-19. Our accumulated evidence obtained from scientific databases particularly PubMed and Google Scholar databases indicate that mannose-specific/mannose-binding lectins (MBL) have potent efficacies like anti-infectivity, complement cascade induction, immunoadjuvants, DC-SIGN antagonists, or glycomimetic approach, which can prove useful in the strategy of COVID-19 combat along with the glycobiological aspects of SARS-CoV-2 infections and antiviral immunity. For example, plant-derived mannose-specific lectins BanLac, FRIL, Lentil, and GRFT from red algae can inhibit and neutralize SARS-CoV-2 infectivity, as confirmed with in-vitro , in-vivo , and in-silico assessments. Furthermore, Bangladesh has a noteworthy resource of antiviral medicinal plants as well as plant lectins. Intensifying research on the antiviral plant lectins, adopting a glyco-biotechnological approach, and with deeper insights into the “glycovirological” aspects may result in the designing of alternative and potent blueprints against the 21st century's biological pandemic of SARS-CoV-2 causing COVID-19

Association of the Mannose-Binding Lectin 2 BB Genotype with COVID-19-Related Mortality

“…For diseases other than COVID-19, clinical trials, which include complement-targeting therapies, are performed for primary IgA nephropathy, which has no disease-specific treatment and might lead to kidney failure [ 11 ]. Recently, some papers have demonstrated that the administration of mannose-specific plant lectins may potentially prevent SARS-CoV-2 infection [ 29 , 30 ], and Takasumi et al [ 31 ] demonstrated that a novel complement inhibitor—the human form of small mannose-binding lectin-associated protein factor H—targets both the lectin and alternative complement pathway. Rambaldi et al [ 25 ] demonstrated that Narsoplimab, a fully human immunoglobulin gamma 4 (IgG4) monoclonal antibody against MASPs, inhibits lectin pathway activation and has anticoagulant effects.…”

Legume Lectins with Different Specificities as Potential Glycan Probes for Pathogenic Enveloped Viruses

“…Algal and cyanobacterial Man-specific lectins, such as griffithsin and cyanovirin-N, also inhibited the entry of HIV and other enveloped viruses in the host cells in vitro and exerted in vivo cytotoxic effects very similar to those of plant lectins [105][106][107].…”

Therapeutic Options for the SARS-CoV-2 Virus: Is There a Key in Herbal Medicine?

“…79 Ahmed et al (2022) demonstrated the role of various lectins exhibiting antiviral activities, especially against SARS-CoV. However, extensive clinical evidence is required to support the statement 80 (Table 1).…”