Antibacterial Activity of Plant Lectins: a Review

Abstract

Lectins are proteins that form a heterogeneous group, capable of binding specifically and reversibly to carbohydrates. They occur in various types of organisms, having different functions, in plants they are present in almost all structures, however with greater proportion in seeds roots and rhizomes. This review aims to provide a more detailed understanding of the antibacterial action of lectins and their biotechnological potential against pathogenic bacteria in the last ten years. Several mechanisms of action are described for the antibacterial activity of these proteins among which the best known occurs due to the interaction between the binding site of the lectin and the carbohydrates exposed on the bacterial cell surface. In vivo studies demonstrate that lectins act on the cascade of cytokines and influencing the level of nitric oxide as ways to decrease bacterial infection. To date, lectins have performed a wide antibacterial activity, emphasizing that each lectin acts according to its carbohydrate specificity, in this way, it is possible to have a distinct performance according to the plant species that are extracted. Thus, being an alternative to the antibacterial resistance that occurs in response to antibiotics. Furthermore, more studies with this theme are necessary for clinical application.

Carbohydrate-Binding Properties and Antimicrobial and Anticancer Potential of a New Lectin from the Phloem Sap of Cucurbita pepo

“…Microorganisms often display surface carbohydrates that plant lectins can target [ 31 ]. For instance, the lipopolysaccharide of Shigella contains O-antigen backbones consisting of a repetition of three rhamnoses and one N -acetylglucosamine.…”

Mannose-Binding Lectins as Potent Antivirals against SARS-CoV-2

“…The C. brasiliensis and D. violacea seeds were collected from plants located at Crato, Ceará, Brazil, and the ConBR and DVL lectins were purified as previously described Lectins isolated from plants have been used as biotechnological tools against several infectious diseases [29], demonstrating potent antibacterial and antiviral effects [30][31][32][33]. In the antiviral context, lectins isolated from seeds of Bauhinia variegata (specificity for glucose and galactose) demonstrated activity against Coxsackievirus B3 and Rotavirus [34,35]; from Momordica charantia (specificity for galactose and N-Acetylgalactosamine) against HIV, HSV-1, H1N1, H3N2, and H5N1 [36][37][38][39]; from Mucuna pruriens (specificity for mannose) against HCV [40]; and from Senna tora (specificity for mannose and galactose) against SARS-CoV-2 [41,42].…”

An Update of Lectins from Marine Organisms: Characterization, Extraction Methodology, and Potential Biofunctional Applications

“…Gram-positive bacteria have teichuronic acids, teichoic, and peptidoglycan ( Figure 4 A), whereas Gram-negative bacteria contain lipopolysaccharides ( Figure 4 B). Hydrophobic interactions, van der Waals, and Hydrogen bridges between lectin and sugar site help lectin to bind the carbohydrates, exposed on the outer membrane or cell wall of the bacteria [ 144 ]. It helps to generate a site in the cell membrane, creating its target to apoptosis by removing of intracellular components [ 144 ].…”

“…Hydrophobic interactions, van der Waals, and Hydrogen bridges between lectin and sugar site help lectin to bind the carbohydrates, exposed on the outer membrane or cell wall of the bacteria [ 144 ]. It helps to generate a site in the cell membrane, creating its target to apoptosis by removing of intracellular components [ 144 ]. The antibacterial mechanism of lectin is shown in Figure 4 C.…”