Recombinant banana lectin as mucosal immunostimulator

Banana Lectin: A Novel Immunomodulatory Strategy for Mitigating Inflammatory Bowel Disease

Compared to the general population, patients with inflammatory bowel disease (IBD) are less likely to be vaccinated, putting them at an increased risk of vaccine-preventable illnesses. This risk is further compounded by the immunosuppressive therapies commonly used in IBD management. Therefore, developing new treatments for IBD that maintain immune function is crucial, as successful management can lead to better vaccination outcomes and overall health for these patients. Here, we investigate the potential of recombinant banana lectin (rBanLec) as a supporting therapeutic measure to improve IBD control and possibly increase vaccination rates among IBD patients. By examining the therapeutic efficacy of rBanLec in a murine model of experimental colitis, we aim to lay the foundation for its application in improving vaccination outcomes. After inducing experimental colitis in C57BL/6 and BALB/c mice with 2,4,6-trinitrobenzene sulfonic acid, we treated animals orally with varying doses of rBanLec 0.1-10 µg/mL (0.01-1 µg/dose) during the course of the disease. We assessed the severity of colitis and rBanLec's modulation of the immune response compared to control groups. rBanLec administration resulted in an inverse dose-response reduction in colitis severity (less pronounced weight loss, less shortening of the colon) and an improved recovery profile, highlighting its therapeutic potential. Notably, rBanLec-treated mice exhibited significant modulation of the immune response, favoring anti-inflammatory pathways (primarily reduction in a local [TNFα]/[IL-10]) crucial for effective vaccination. Our findings suggest that rBanLec could mitigate the adverse effects of immunosuppressive therapy on vaccine responsiveness in IBD patients. By improving the underlying immune response, rBanLec may increase the efficacy of vaccinations, offering a dual benefit of disease management and prevention of vaccine-preventable illnesses. Further studies are required to translate these findings into clinical practice.

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

The SARS-CoV-2 entry into host cells is mainly mediated by the interactions between the viral spike protein (S) and the ACE-2 cell receptor, which are highly glycosylated. Therefore, carbohydrate binding agents may represent potential candidates to abrogate virus infection. Here, we evaluated the in vitro anti-SARS-CoV-2 activity of two mannose-binding lectins isolated from the Brazilian plants Canavalia brasiliensis and Dioclea violacea (ConBR and DVL). These lectins inhibited SARS-CoV-2 Wuhan-Hu-1 strain and variants Gamma and Omicron infections, with selectivity indexes (SI) of 7, 1.7, and 6.5, respectively for ConBR; and 25, 16.8, and 22.3, for DVL. ConBR and DVL inhibited over 95% of the early stages of the viral infection, with strong virucidal effect, and also protected cells from infection and presented post-entry inhibition. The presence of mannose resulted in the complete lack of anti-SARS-CoV-2 activity by ConBR and DVL, recovering virus titers. ATR-FTIR, molecular docking, and dynamic simulation between SARS-CoV-2 S and either lectins indicated molecular interactions with predicted binding energies of -85.4 and -72.0 Kcal/Mol, respectively. Our findings show that ConBR and DVL lectins possess strong activities against SARS-CoV-2, potentially by interacting with glycans and blocking virus entry into cells, representing potential candidates for the development of novel antiviral drugs.

Exploitation of polyphenols and proteins using nanoencapsulation for anti-viral and brain boosting properties - Evoking a synergistic strategy to combat COVID-19 pandemic

The world is currently under the threat of COVID pandemic and has focused every dimension of research in finding a cure to this novel disease. In this current situation, people are facing mental stress, agony, fear, depression and other associated symptoms which are taking a toll on their overall mental health. Nanoencapsulation of certain brain boosting polyphenols including quercetin, caffeine, cocoa flavanols and proteins like lectins can become new area of interest in the present scenario. Besides the brain boosting benefits, we have also highlighted the anti- viral activities of these compounds which we assume can play a possible role in combating COVID-19 given to their previous history of action against certain viruses. This review outlines the nanoencapsulation approaches of such synergistic compounds as a novel strategy to take the ongoing research a step ahead and also provides a new insight in bringing the role of nanotechnology in addressing the issues related to COVID pandemic.

BanLec-eGFP Chimera as a Tool for Evaluation of Lectin Binding to High-Mannose Glycans on Microorganisms

Fluorescently labeled lectins are useful tools for in vivo and in vitro studies of the structure and function of tissues and various pathogens such as viruses, bacteria, and fungi. For the evaluation of high-mannose glycans present on various glycoproteins, a three-dimensional (3D) model of the chimera was designed from the crystal structures of recombinant banana lectin (BanLec, Protein Data Bank entry (PDB): 5EXG) and an enhanced green fluorescent protein (eGFP, PDB 4EUL) by applying molecular modeling and molecular mechanics and expressed in Escherichia coli. BanLec-eGFP, produced as a soluble cytosolic protein of about 42 kDa, revealed β-sheets (41%) as the predominant secondary structures, with the emission peak maximum detected at 509 nm (excitation wavelength 488 nm). More than 65% of the primary structure was confirmed by mass spectrometry. Competitive BanLec-eGFP binding to high mannose glycans of the influenza vaccine (Vaxigrip®) was shown in a fluorescence-linked lectin sorbent assay (FLLSA) with monosaccharides (mannose and glucose) and wild type BanLec and H84T BanLec mutant. BanLec-eGFP exhibited binding to mannose residues on different strains of Salmonella in flow cytometry, with especially pronounced binding to a Salmonella Typhi clinical isolate. BanLec-eGFP can be a useful tool for screening high-mannose glycosylation sites on different microorganisms.

Antiviral lectins: Selective inhibitors of viral entry

Many natural lectins have been reported to have antiviral activity. As some of these have been put forward as potential development candidates for preventing or treating viral infections, we have set out in this review to survey the literature on antiviral lectins. The review groups lectins by structural class and class of source organism we also detail their carbohydrate specificity and their reported antiviral activities. The review concludes with a brief discussion of several of the pertinent hurdles that heterologous proteins must clear to be useful clinical candidates and cites examples where such studies have been reported for antiviral lectins. Though the clearest path currently being followed is the use of antiviral lectins as anti-HIV microbicides via topical mucosal administration, some investigators have also found systemic efficacy against acute infections following subcutaneous administration.

Traditional uses, phytochemistry and pharmacology of wild banana (Musa acuminata Colla): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Musa acuminata, the wild species of banana is a plant of the tropical and subtropical regions. Over the past few decades, the health benefits of M. acuminata have received much attention. All parts of the plant including fruits, peel, pseudostem, corm, flowers, leaves, sap and roots have found their use in the treatment of many diseases in traditional medicine. Literature review have indicated use of M. acuminata in the treatment of various diseases such as fever, cough, bronchitis, dysentery, allergic infections, sexually transmitted infections, and some of the non-communicable diseases. The reported pharmacological activities of M. acuminata include antioxidant, antidiabetic, immunomodulatory, hypolipidemic, anticancer, and antimicrobial especially anti-HIV activity. This review presents information on the phytochemicals and pharmacological studies to validate the traditional use of different parts of M. acuminata in various diseases and ailments. A comprehensive assessment of the biological activities of M. acuminata extracts is included and possible mechanisms and phytochemicals involved have also been correlated to provide effective intervention strategies for preventing or managing diseases.

MATERIALS AND METHODS

A literature search was performed on M. acuminata using ethnobotanical textbooks, published articles in peer-reviewed journals, local magazines, unpublished materials, and scientific databases such as Pubmed, Scopus, Web of Science, ScienceDirect, and Google Scholar. The Plant List, Promusa, Musalit, the Integrated Taxonomic Information System (ITIS) databases were used to validate the scientific names and also provide information on the subspecies and cultivars of M. acuminata.

RESULT AND DISCUSSION

The edible part of M. acuminata provides energy, vitamins and minerals. All other parts of the plant have been used in the treatment of many diseases in traditional medicine. The rich diversity of phytochemicals present in them probably contributes to their beneficial effects, and validates the role of M. acuminata plant parts used by various tribes and ethnic groups across the geographical areas of the world.

CONCLUSION

This review presents information on phytochemicals and pharmacological activities of M. acuminata plant parts. Pharmacological studies support the traditional uses of the plant, and probably validate the uses of M. acuminata by the indigenous people to treat and heal many infections and diseases. Some studies on animal models have been carried out, which also provide evidence of efficacy of the M. acuminata plant as a therapeutic agent. These observations suggest that M. acuminata plant parts possesses pluripharmacological properties, and can be used in designing potent therapeutic agents. However, individual bioactive constituent(s) from different parts of this plant need further investigations to confirm various pharmacological claims, and to explore the potential of M. acuminata in the development of drugs and use in functional foods.

Banana lectin: a brief review

Lectins are a group of proteins of non-immune origin that recognize and bind to carbohydrates without modifying them. Banana is the common name for both herbaceous plants of the genus Musa and for the fruit they produce. They are indeed a promising source for many medicinal applications. Banana lectins have the potential for inhibiting HIV-1 reverse transcriptase activity, suppressing cancer cell proliferation and stimulating macrophage activities. Nevertheless, compared to other plant lectins, there is relatively little information in the literature on banana lectins, particularly with respect to their structure and biological functions. Herein we focus our review on the structure, functions and exploitable properties of banana lectins.