Concanavalin A as a promising lectin-based anti-cancer agent: the molecular mechanisms and therapeutic potential

Photocatalytic effect of gold-zinc oxide composite nanostructures for the selective and controlled killing of antibiotic-resistant bacteria and the removal of resistant bacterial biofilms from the body

Infections involving antibiotic-resistant bacteria have become a major problem. Pathogenic bacteria use mechanisms such as drug target bypass, target modification, and biofilm formation to evade treatment. To respond to these problems, antibacterial research using metal and metal oxide nanoparticles is currently active. Nanoparticles treat bacterial infections through reactive oxygen species generation or antibacterial ion release. However, their application has faced problems related to human compatibility, as they react non-specifically, targeting both mammalian and bacterial cells. In addition, ZnO nanoparticles show low antibacterial activity against Gram-negative bacteria. Thus, the demand for antibacterial substances with enhanced specificity and improved efficacy is increasing. We bound gold to the surface of ZnO nanoparticles, enabling photocatalytic and photothermal actions through visible light irradiation. To improve bacterial specificity, Concanavalin A (Con A), a lectin that can specifically target bacterial membrane lipopolysaccharides, was conjugated with the nanoparticles. We showed that Con A-conjugated Au/ZnO nanoparticles (Au/ZnO-Con A) exhibit photocatalytic and photothermal effects under white light, enhancing their antibacterial ability, and through enhanced specificity, increased antibacterial and anti-biofilm abilities were confirmed. The developed particles showed the potential to alleviate antibiotic resistance in a bacterial skin infection model, presenting a new platform for treating bacterial infections.

Dapansutrile mitigates concanavalin A- induced autoimmune hepatitis: Involvement of NLRP3/IL-1β and JNK/ p38 MAPK pathways

AIM

Dapansutrile (Dapan) is a newly developed anti-inflammatory molecule that supresses the production of NLRP3 inflammasome-dependent IL-1β. Its hepatoprotective effects against autoimmune hepatitis (AIH) have not yet been explored. Hence, this study was conducted to examine the possible protective effects of Dapan against concanavalin A (Con A)-induced hepatitis in mice.

MAIN METHODS

Mice were randomly divided into five groups (n = 6): control, Con A (15 mg/kg), Dapan (60 mg/kg), Dapan (6 mg/kg) + Con A, and Dapan (60 mg/kg) + Con A. Mice were euthanised at the end of the study, and blood and hepatic tissues were collected.

KEY FINDINGS

Hepatic function testing using lactate dehydrogenase, alanine aminotransferase, and aspartate aminotransferase levels, in addition to hepatic tissue histological examination, revealed that intraperitoneal administration of Dapan noticeably ameliorated Con A-induced hepatic enzyme impairment and histopathological disruption. Moreover, Dapan-treated mice had significantly lower malondialdehyde hepatic content and elevated reduced glutathione, superoxide dismutase, and total antioxidant capacity levels than non-treated mice in a dose-dependent manner. The Dapan-treated groups showed significantly lower levels of the inflammatory mediators, NLRP3, TNF-α, IL-6, and IL-1β, in addition to the immunomodulators CD8, CD4, INF-γ, and NFκB and inhibition of JNK and p38 MAPK levels compared to the Con A-treated group.

SIGNIFICANCE

Our results showed that intraperitoneal administration of Dapan could be a therapeutic opportunity to inhibit the development of AIH via inhibition of inflammatory pathways.

ConA-glutamate interactions: New insights into its neuroprotective effect

L-Glutamate is the primary excitatory neurotransmitter in the brain; excessive levels induce L-glutamate-mediated excitotoxicity, linked to Alzheimer's and Parkinson's. Plant-derived molecules with antioxidant and anti-inflammatory properties that modulate this are of interest. Canavalia ensiformis lectin (ConA) serves as a model lectin for CNS studies. This study aimed to analyze in vitro and in silico the neuroprotective potential of ConA against glutamatergic excitotoxicity and identify the involved protein domain and mechanisms. Native and demetallized ConA were used for cytotoxicity and neuroprotection assays in PC12 cells. Molecular docking and fluorescence spectroscopy were also employed. ConA (1-50 mM) did not show cytotoxicity in PC12 cells and protected them from glutamatergic excitotoxicity at 15.6 μg/mL, significantly increasing cell viability from 80 % to over 90 %. Furthermore, affinity and binding assays indicated that the carbohydrate recognition domain was not involved in neuroprotection; instead, the amino acid-binding site played a crucial role. Our findings conclude that ConA possesses neuroprotective potential against glutamatergic excitotoxicity in PC12 cells via an L-glutamate sequestration mechanism mediated by the amino acid-binding site.

Assembly and Functionality of 2D Protein Arrays

Among the unique classes of 2D nanomaterials, 2D protein arrays garner increasing attention due to their remarkable structural stability, exceptional physiochemical properties, and tunable electronic and mechanical attributes. The interest in mimicking and surpassing the precise architecture and advanced functionality of natural protein systems drives the field of 2D protein assembly toward the development of sophisticated functional materials. Recent advancements deepen the understanding of the fundamental principles governing 2D protein self-assembly, accelerating the creation of novel functional biomaterials. These developments encompass biological, chemical, and templated strategies, facilitating the self-organization of proteins into highly ordered and intricate 2D patterns. Consequently, these 2D protein arrays create new opportunities for integrating diverse components, from small molecules to nanoparticles, thereby enhancing the performance and versatility of materials in various applications. This review comprehensively assesses the current state of 2D protein nanotechnology, highlighting the latest methodologies for directing protein assembly into precise 2D architectures. The transformative potential of 2D protein assemblies in designing next-generation biomaterials, particularly in areas such as biomedicine, catalysis, photosystems, and membrane filtration is also emphasized.

Immunomodulatory lectin from Cordia myxa targets PI3K/AKT signalling mediated apoptosis to regress both in-vitro and in-vivo tumour

Plant based medicine is gaining recognition as a complementary approach to conventional treatments. Plants contain lectins that bind to carbohydrates and exhibit various biological properties and being used in cancer treatment. In present investigation Cordia myxa fruit was chosen, screen for presence of lectin and explore its biological role. Screening of lectin was conducted through HA activity. Purification and characterization through conventional methods. HI assay to confirm the carbohydrate specificity. Immunomodulatory role by proliferative assays and ELISA. Apoptosis by annexin-V stain, TUNEL, MOMP and COMET assay and in-vivo antitumour activity by EAC induced ascites and solid tumour model. Gene expression through IB and IHC. The results illustrated that, presence of immunostimulant, ̴12 kDa lectin (CML) with strong leucoaggulutination activity having ovalbumin & fetuin specificity. The CML exhibits immune cell proliferation and secretes immune cytokines IL-2, IL-10 & IL-12. The immunomodulatory experiments infer that, CML induces anti-proliferative response against A549 and EAC by inducing apoptosis, which were validated in an in-vitro & in-vivo models. Mechanistically, CML modulates phosphorylation of PI3K/AKT signalling pathways and modulates downstream apoptotic proteins P53, Bax, Bad, Bcl-2, cytochrome-c, caspase-3 and DFF-40. Overall, the study reports the immunomodulatory lectin in Cordia myxa with its potential therapeutic role.

Regulation of PD-L1 glycosylation and advances in cancer immunotherapy

Protein glycosylation plays a versatile role in regulating homeostasis, such as cell migration, protein sorting, and the immune response. Drugs aimed at targeting glycosylation have strong implications for immunity enhancement, diagnosis, and cancer regression. Programmed death-ligand 1 (PD-L1), expressed in cancer or antigen-presenting cells, binds to programmed cell death protein 1 (PD-1) and suppresses T cells. Glycosylation of PD-L1 at N35, N192, N200, and N219 stabilizes PD-L1 on the cancer cell surface, which contributes to immune evasion by inhibiting T cell activity. To date, at least six glycosyltransferases and four associate proteins are known to regulate PD-L1 glycosylation. Terminal modifications such as poly-N-acetyl-lactosamine (poly-LacNAC), sulfation, and sialylation are commonly found on PD-L1, acting as an immune recognition ligand and regulating certain immune responses. Studies have identified many mechanisms and potential therapeutic targets within the glycosylation pathways of PD-L1, revealing their involvement in cancer pathology, immune evasion, and resistance to immunotherapy. In this review, we covered the glycoforms, terminal moiety, binding lectin, glycosyltransferase, as well as sugar analogs focusing on glycosylated PD-L1. We present a mechanism that originates from the endoplasmic reticulum (ER)-Golgi apparatus (Golgi) and its subsequent translocation to the cell membrane. This pathway determines the immune suppression function of PD-L1 and therefore regulates the immune response such as T cells, monocytes, and macrophages. This collection of findings underscores the significance of glycosylation in the role of PD-L1 in cancer and highlights multiple potential targets and strategies for improving therapeutic intervention and diagnostic techniques.

The Multifaceted Chemistry of Chili Peppers: A Biodiversity Treasure for Nutrition and Biomedicine

Due to its biodiversity, traditional medicine has been recognized worldwide for centuries and continues to affect the development of complementary and alternative therapies. A wide variety of spices, herbs, and trees are known for their curative effects. Chili pepper (Ch-p), a spice-utilizing fruit, is rich in natural medicinally bioactive compounds, such as flavonoids, capsaicinoids, and many other phytochemicals and phytonutrients. Operating in synergy and consortium, these compounds demonstrate their functionality, in comparison to lonely treatment, as active agents in handling many disorders. These may include abnormal coagulation, oxidative stress, obesity, diabetes, inflammation, cancer, and microbe-inducing diseases. Recently, capsaicinoids, particularly capsaicin, have been shown to manage the symptoms of significant viral diseases, including COVID-19. Capsaicin also has the potential to be an effective anesthetic agent and enables Ch-p to be expandedly employed as a topical preparation in relieving pain as well. The phytochemicals of Ch-p are not only beneficial and inexpensive phyto-alternatives in disease management, but they can also be used as scaffolds for the production of novel medicines. The study also substantiates the role of the TRPV1 receptor in the mitigation of chronic diseases in conjunction with capsaicin. Nevertheless, the consumption of Ch-p is the subject of limited medicinal research, necessitating the confirmation of the results from animal studies. The nutritional and biomedical prospection of Ch-p-derived products has been addressed in an accessible format in this artifact, with the potential to precisely enhance and enrich our pharmaceutical industries in the pursuit of human well-being.

Lectin: A Molecular Tool in Cancer Diagnosis and Therapy with Special Reference to Reproductive Cancers

The prevalence of cancer deaths globally and domestically is higher especially due to the deferment of diagnosis and lack of facilities for women's reproductive cancers. The present review focussed to explore the application of lectins in cancer theranostics. Though there is cancer diagnostic and treatment available there is no promising early diagnostic tool and effective treatment available for the cancer which is the major concern. Lectins are cellulose-binding proteins that are strongly determined in saccharide groups of glycans, glycopeptides, or glycolipids. In the concomitance of events in cells, carbohydrates, and proteins, lectins play an important role. Lectins bind superiorly to the cancer cell membrane and their receptors induce the cytotoxic effect, which results in caspase-mediated cell death, and prohibits tumour development. Lectin snuffing also reveals polyamine stocks and impedes the growth of cancerous cells. They affect the cell cycle by non-apoptotic aggregation, seizure of the cell cycle phase G2, M, and the mediation of caspases. It can also adversely affect the action of telomerase and hinder vascularisation. They promote immunomodulation and adversely limit protein synthesis. Their easy availability and its characteristics support its use in cancer diagnosis and therapy, despite their small corollary effects. Future investigations recommend focussing more on the key applications of lectin by reducing its concurrent effects and carrying out more in-vitro investigations. However, the use of lectin formulations for cancer theranostics is a new area in cancer detection and treatment. In this review, plant lectin appears to be a potential target for cancer research in the fields of diagnosis and theranostics.

The Promising Role of Plant-Derived Lectins in Oral Cancer Therapeutics: A Systematic Review

Oral cancer (OC) continues to pose a significant global health challenge, marked by high morbidity and mortality rates despite advances in diagnosis and treatment. Numerous novel potential anticancer drugs have been evaluated, many of which are derived from natural sources, such as microorganisms, plants, and animals. Among these, plant lectins - a distinctive group of proteins and glycoproteins with strong biological activity - have garnered considerable attention over the years. Several plant lectins can trigger selective apoptotic cancer cell death or possess antiproliferative properties. The objective of this systematic review was to provide insight into the potential applications of plant lectins in the treatment of OC. Plant lectins suppress cancer cells by inducing apoptosis and/or autophagy by modulating various signalling pathways such as the caspase family, mitochondrial-mediated ROS-p38-p53 pathway, PI3K/Akt, and Wnt/β-catenin to inhibit OC. Multiple lectins have been shown to exhibit anticancer properties in cell cultures and in vivo. Polygonatum cyrtonema lectin, Maackia amurensis seed lectin, abrus agglutinin, wheat germ agglutinin, mistletoe lectin, and concanavalin A are among the plant lectins with the highest potential for anticancer activities. This review provides an overview of the current understanding of the role of lectins in cancer diagnosis and therapy, highlighting their potential applications and underlying mechanisms.

Antibacterial and anticancer activities of three novel lectin-conjugated chitosan nanoparticles

To the best of our knowledge, this is the first attempt to synthesize, characterize, and determine the antibacterial and anticancer effects of three novel conjugates of plant lectins: phytohemagglutinin lectin (PHA), soybean agglutinin (SBA), and peanut agglutinin (PNA) with chitosan nanoparticles (CHNPs). The lectin concentration within prepared conjugates was estimated using nannodrop, and the highest concentration was 0.96 mg/ml in PHA-CHNPs. SDS-PAGE showed the molecular weights of conjugates ranged from 26.9 to 63.9 kDa. UV spectrophotometer recorded the absorbance peaks of conjugates somewhere between 200 and 230 nm. Hemagglutination analysis verified the presence of actively binding lectins. The three conjugates showed strong antibacterial activity against Gram-positive and Gram-negative bacteria compared to pure lectins and chitosan nanoparticles. The highest inhibition zone was 55.67 ± 4.04, 38.67 ± 5.51, and 37.33 ± 2.52 for PHA-CHNPs against Enterococcus faecalis, Salmonella typhimurium, and Shigella sonnei, respectively, followed by 36.3 ± 0.15 for PNA-CHNPs against Staphylococcus aureus. The lowest MIC was 1.5 µg/ml for PHA-CHNPs against Enterococcus faecalis, followed by 12 µg/ml for PNA-CHNPs and SBA-CHNPs against Salmonella typhimurium and Enterococcus faecalis, respectively. TEM microphotographs show the conjugation pattern between lectins and chitosan nanoparticles and the morphological differences between control, treated bacteria, and cancer cells. Moreover, 100 μg/ml of PHA-CHNPs affect tongue carcinoma (HNO-97), colorectal cancer (HT-29), and human melanoma (A375) cancer cell lines, reducing cell viability by 38.78 ± 1.85%, 49.88 ± 1.11%, and 66.92 ± 3.60%, respectively. This study develops three innovative conjugates of lectin chitosan nanoparticles that need to be tested as potential antibacterial and anticancer agents for medical and cancer therapy applications. KEY POINTS: • Lectin-conjugated chitosan nanoparticles exhibit antibacterial activity. • All conjugates are safe for oral epithelial cells and human skin fibroblasts. • The PHA-CHNP conjugates have anticancer activity against HNO-97, HT-29, and A375.

Liquid Phase Exfoliation of Protein Parent Crystals into Nanosheets and Fibrils Based on Orthogonal Supramolecular Interactions

Proteins are attractive building blocks for fabricating diverse and precise nanomaterials. However, the facile fabrication of multidimensional artificial assemblies is highly challenging. Here, inspired by the large-scale production technique of inorganic nanomaterials, we demonstrate the application of liquid phase exfoliation (LPE) on native protein ConA by the design of synthetic ligands. These ligands provide distinct in-plane and out-of-plane supramolecular interactions, allowing the generation of multidimensional architectures based on the same protein by dissociating a single interaction in solution, including 3D porous protein crystals, 2D sizable nanosheets, and 1D fibrils. Importantly, the exfoliated 2D sheets were dozens of times larger than the self-assembled nanosheets, resulting in a dramatic enhancement of the intrinsic bioactivity of the building blocks by receptor clustering and less endocytosis. These findings enable the successful application of LPE on biomacromolecules and open up an alternative avenue to generate advanced multidimensional nanomaterials, without the need for complex protein design and careful adjustment of self-assembly conditions.

Deciphering Pathways and Thermodynamics of Protein Assembly Using Native Mass Spectrometry

Protein oligomerization regulates many critical physiological processes, and its dysregulation can contribute to dysfunction and diseases. Elucidating the assembly pathways and quantifying their underlying thermodynamic and kinetic parameters are crucial for a comprehensive understanding of biological processes and for advancing therapeutics targeting abnormal protein oligomerization. Established binding assays, with limited mass precision, often rely on simplified models for data interpretation. In contrast, high-resolution native mass spectrometry (nMS) can directly determine the stoichiometry of biomolecular complexes in vitro. However, quantification is hindered by the fact that the relative abundances of gas-phase ions generally do not reflect solution concentrations due to nonuniform response factors. Recently, slow mixing mode (SLOMO)-nMS, which can quantify the relative response factors of interacting species, has been demonstrated to reliably measure the affinity (Kd) of binary biomolecular complexes. Here, we introduce an extended form of SLOMO-nMS that enables simultaneous quantification of the thermodynamics in multistep association reactions. Application of this method to homo-oligomerization of concanavalin A and insulin confirmed the reliability of the assay and uncovered details about the assembly processes that had previously resisted elucidation. Results acquired using SLOMO-nMS implemented with charge detection shed new light on the binding of recombinant human angiotensin-converting enzyme 2 and the SARS-CoV-2 spike protein. Importantly, new assembly pathways were uncovered, and the affinities of these interactions, which regulate host cell infection, were quantified. Together, these findings highlight the tremendous potential of SLOMO-nMS to accelerate the characterization of protein assembly pathways and thermodynamics and, in so doing, enhance fundamental biological understanding and facilitate therapeutic development. https://orcid.org/0000-0002-3389-7112.

Antinutrients in Halophyte-Based Crops

The cultivation of halophytes is an alternative approach to sustain agricultural productivity under changing climate. They are densely equipped with a diverse group of metabolites that serve multiple functions, such as providing tolerance to plants against extreme conditions, being used as a food source by humans and ruminants and containing bioactive compounds of medicinal importance. However, some metabolites, when synthesized in greater concentration above their threshold level, are considered antinutrients. Widely reported antinutrients include terpenes, saponins, phytate, alkaloids, cyanides, tannins, lectins, protease inhibitors, calcium oxalate, etc. They reduce the body's ability to absorb essential nutrients from the diet and also cause serious health problems. This review focuses on antinutrients found both in wild and edible halophytes and their beneficial as well as adverse effects on human health. Efforts were made to highlight such antinutrients with scientific evidence and describe some processing methods that might help in reducing antinutrients while using halophytes as a food crop in future biosaline agriculture.

Lectins in oncology and virology: Mechanisms of anticancer activity and SARS-CoV-2 inhibition

Lectins are proteins or glycoproteins of non-immune origin with carbohydrate-binding properties. They are found both prokaryotic and eukaryotic organisms. The most abundant source of the lectins are plants. Many lectins have anticancer effects by directly exerting cytotoxic effects on malignant cells or indirectly activating the immune system. Lectins also have antiviral activities. These proteins can recognise glycoproteins on the surface of enveloped viruses and bind to them. This creates a physical barrier between them and the corresponding receptors on the surface of the host cell, which prevents the virus from entering the cell and can thus effectively inhibit the replication of the virus. In this review, we focus on the anticancer activities of selected lectins and the underlying mechanisms. We also discuss different types of lectins with antiviral activity. We have paid special attention to lectins with inhibitory activity against SARS-CoV-2. Finally, we outline the challenges of using lectins in therapy and suggest future research directions.

Biomimetic protein structural transitions regulate activation and inhibition of the broad-spectrum bactericidal activity of cationic nanoparticles

The development of cationic polymers as alternative materials to antibiotics necessitates addressing the challenge of balancing their antimicrobial activity and toxicity. Here we propose a precise switching strategy inspired by biomimetic voltage-gated ion channels, enabling controlled activation and inhibition of cationic antimicrobial functions through protein conformational transitions in diverse physiological environments. Following thermodynamic studies on the specific recognition between mannose end groups on polycations and concanavalin A (ConA), we synthesized a type of ConA-polycation nanoparticle. The nanoparticle was inhibited under neutral conditions, with cationic moieties shielded by ConA's β-sheet. This shielding suppresses their antimicrobial activity, thereby ensuring satisfactory biocompatibility. In mildly acidic environments, however, the transition of a portion of ConA to an α-helix conformation exposed cations at the particle periphery, activating antibacterial functionality. Compared to inhibited nanoparticles, those in the activated state exhibited a 32-256 times reduction in the minimum bactericidal concentration against bacteria and fungi (2-16 µg/mL). In a murine acute pulmonary infection model, intravenous administration of inhibited nanoparticles effectively reduced bacterial counts by 4-log within 12 h. The biomimetic design, regulating cationic antimicrobial functionality through the alteration in protein secondary structure, significantly retards bacterial resistance development, holding great promise for intelligent antimicrobial materials. STATEMENT OF SIGNIFICANCE: Cationic antimicrobial polymers exhibit advantages distinct from antibiotics due to their lower propensity for resistance development. However, the presence of cationic moieties also poses a threat to healthy cells and tissues, significantly constraining their potential for clinical applications. To address this challenge, we propose a biomimetic strategy that mimics voltage-gated ion channels to activate the antimicrobial functionality of cations selectively in bacterial environments through the conformational transitions of proteins between β-sheets and α-helices. In healthy tissues, the antimicrobial functionality is inhibited, ensuring satisfactory biocompatibility. Antimicrobial cationic materials capable of intelligent switching between an activated state and an inhibited state in response to environmental changes offer an effective strategy to prevent the development of resistance and mitigate potential side effects.

Techno-Functions and Safety Concerns of Plant-Based Peptides in Food Matrices

Plant-based peptides (PBPs) benefit functional food development and environmental sustainability. Proteolysis remains the primary method of peptide production because it is a mild and nontoxic technique. However, potential safety concerns still emanate from toxic or allergenic sequences, amino acid racemization, iso-peptide bond formation, Maillard reaction, dose usage, and frequency. The main aim of this review is to investigate the techno-functions of PBPs in food matrices, as well as their safety concerns. The distinctive characteristics of PBPs exhibit their techno-functions for improving food quality and functionality by contributing to several crucial food formulations and processing. The techno-functions of PBPs include solubility, hydrophobicity, bitterness, foaming, oil-binding, and water-holding capacities, which subsequently affect food matrices. The safety and quality of foodstuff containing PBPs depend on the proper source of plant proteins, the selection of processing approaches, and compliance with legal regulations for allergen labeling and safety evaluations. The safety concerns in allergenicity and toxicity were discussed. The conclusion is that food technologists must apply safe limits and consider potential allergenic components generated during the development of food products with PBPs. Therefore, functional food products containing PBPs can be a promising strategy to provide consumers with wholesome health benefits.

Concanavalin A Delivers a Photoactive Protein to the Bacterial Wall

Modular supramolecular complexes, where different proteins are assembled to gather targeting capability and photofunctional properties within the same structures, are of special interest for bacterial photodynamic inactivation, given their inherent biocompatibility and flexibility. We have recently proposed one such structure, exploiting the tetrameric bacterial protein streptavidin as the main building block, to target S. aureus protein A. To expand the palette of targets, we have linked biotinylated Concanavalin A, a sugar-binding protein, to a methylene blue-labelled streptavidin. By applying a combination of spectroscopy and microscopy, we demonstrate the binding of Concanavalin A to the walls of Gram-positive S. aureus and Gram-negative E. coli. Photoinactivation is observed for both bacterial strains in the low micromolar range, although the moderate affinity for the molecular targets and the low singlet oxygen yields limit the overall efficiency. Finally, we apply a maximum entropy method to the analysis of autocorrelation traces, which proves particularly useful when interpreting signals measured for diffusing systems heterogeneous in size, such as fluorescent species bound to bacteria.

Recent Insights into Glucose-Responsive Concanavalin A-Based Smart Hydrogels for Controlled Insulin Delivery

Many efforts are continuously undertaken to develop glucose-sensitive biomaterials able of controlling glucose levels in the body and self-regulating insulin delivery. Hydrogels that swell or shrink as a function of the environmental free glucose content are suitable systems for monitoring blood glucose, delivering insulin doses adapted to the glucose concentration. In this context, the development of sensors based on reversible binding to glucose molecules represents a continuous challenge. Concanavalin A (Con A) is a bioactive protein isolated from sword bean plants (Canavalia ensiformis) and contains four sugar-binding sites. The high affinity for reversibly and specifically binding glucose and mannose makes Con A as a suitable natural receptor for the development of smart glucose-responsive materials. During the last few years, Con A was used to develop smart materials, such as hydrogels, microgels, nanoparticles and films, for producing glucose biosensors or drug delivery devices. This review is focused on Con A-based materials suitable in the diagnosis and therapeutics of diabetes. A brief outlook on glucose-derived theranostics of cancer is also presented.

Harmful Free Radicals in Aging: A Narrative Review of Their Detrimental Effects on Health

The production of harmful free radicals (H-FRs), especially those with oxygen or nitrogen atoms, depends on both internal and environmental causes. The negative effects of H-FRs are greatly alleviated by antioxidant protection. The harmful impact of oxidative stress, or OS, is brought on by a disparity between the defense mechanisms of the body and the creation of H-FRs. Aging is characterized by a slow decline in tissue and organ competence. Age-mediated pathologies start as an aberrant accumulation of H-FRs, which inhibit cells' capacity to divide, repair, and operate, based on the OS theorem of aging. The natural outcome of this situation is apoptosis. These conditions may include skeletal muscle dysfunction, cancer, cardiovascular, chronic hepatitis, chronic renal, and chronic pulmonary disorders. Given the substantial role that OS plays in the progression of many of these illnesses, antioxidant-based therapy may have a favorable impact on how these diseases progress. To ascertain the true efficacy of this therapy strategy, more research is necessary. The aim of this study is to provide an overview of the literature on this challenging issue that is attracting interest.

The Glycan Ectodomain of SARS-CoV-2 Spike Protein Modulates Cytokine Production and Expression of CD206 Mannose Receptor in PBMC Cultures of Pre-COVID-19 Healthy Subjects

The ability of recombinant, SARS-CoV-2 Spike (S) protein to modulate the production of two COVID-19 relevant, pro-inflammatory cytokines (IL-6 and IFN-γ) in PBMC cultures of healthy, pre-COVID-19 subjects was investigated. We observed that cytokine production was largely and diversely modulated by the S protein depending on antigen or mitogen stimulation, as well as on the protein source, insect (S-in) or human (S-hu) cells. While both proteins co-stimulated cytokine production by polyclonally CD3-activated T cells, PBMC activation by the mitogenic lectin Concanavalin A (Con A) was up-modulated by S-hu protein and down-modulated by S-in protein. These modulatory effects were likely mediated by the S glycans, as demonstrated by direct Con A-S binding experiments and use of yeast mannan as Con A binder. While being ineffective in modulating memory antigenic T cell responses, the S proteins and mannan were able to induce IL-6 production in unstimulated PBMC cultures and upregulate the expression of the mannose receptor (CD206), a marker of anti-inflammatory M2 macrophage. Our data point to a relevant role of N-glycans, particularly N-mannosidic chains, decorating the S protein in the immunomodulatory effects here reported. These novel biological activities of the S glycan ectodomain may add to the comprehension of COVID-19 pathology and immunity to SARS-CoV-2.

Computational insights into the circular permutation roles on ConA binding and structural stability

The mechanisms behind Concanavalin A (ConA) circular permutation have been under investigation since 1985. Although a vast amount of information is available about this lectin and its applications, the exact purpose of its processing remains unclear. To shed light on this, this study employed computer simulations to compare the unprocessed ProConA with the mature ConA. This approach aimed to reveal the importance of the post-translational modifications, especially how they affect the lectin stability and carbohydrate-binding properties. To achieve these goals, we conducted 200 ns molecular dynamics simulations and trajectory analyses on the monomeric forms of ProConA and ConA (both unbound and in complex with D-mannose and the GlcNAc2Man9 N-glycan), as well as on their oligomeric forms. Our findings reveal significant stability differences between ProConA and ConA at both the monomeric and tetrameric levels, with ProConA exhibiting consistently lower stability parameters compared to ConA. In terms of carbohydrate binding properties, however, both lectins showed remarkable similarities in their interaction profiles, contact numbers, and binding free energies with D-mannose and the high-mannose N-glycan. Overall, our results suggest that the processing of ProConA significantly enhances the stability of the mature lectin, especially in maintaining the tetrameric oligomer, without substantially affecting its carbohydrate-binding properties.

Understanding the Mode of Action of a Micro-Immunotherapy Formulation: Pre-Clinical Evidence from the Study of 2LEBV® Active Ingredients

BACKGROUND

Epstein-Barr virus (EBV) is often kept silent and asymptomatic; however, its reactivation induces a chronic and/or recurrent infection that is associated with numerous diseases, including cancer and inflammation-related disorders. As no specific treatment is currently available, the immune factors-based micro-immunotherapy (MI) medicine 2LEBV® could be considered a valuable therapeutic option to sustain the immune system in EBV reactivation.

METHODS

The present work aimed to investigate, for the first time, the effect of 2LEBV® in several in vitro models of uninfected immune-related cells.

RESULTS

2LEBV® displayed phagocytosis-enhancing capabilities in granulocytes. In human peripheral blood mononuclear cells (PBMCs), it increased the intra- and extra-cellular expression of interleukin (IL)-2. Moreover, it modulated the secretion of other cytokines, increasing IL-4, IL-6, and tumor necrosis factor-α levels or lowering other cytokines levels such as IL-9. Finally, 2LEBV® reduced the expression of human leukocyte antigen (HLA)-II in endothelial cells and macrophages.

CONCLUSIONS

Although these data are still preliminary and the chosen models do not consider the underlying EBV-reactivation mechanisms, they still provide a better understanding of the mechanisms of action of 2LEBV®, both at functional and molecular levels. Furthermore, they open perspectives regarding the potential targets of 2LEBV® in its employment as a therapeutic intervention for EBV-associated diseases.

Antitumor Activity of a Lectin Purified from Punica granatum Pulps against Ehrlich Ascites Carcinoma (EAC) Cells

BACKGROUND

Lectins are carbohydrate-binding proteins with various pharmacological activities, such as antimicrobial, antidiabetic, antioxidant, and anticancer. Punica granatum fruit extract has traditional uses, however, the anti-cancer activity of purified lectin isolated from P. granatum pulp is yet to be reported.

OBJECTIVE

The goals of this study are purification, characterization of the lectin from P. granatum, and examination of the purified lectin's anticancer potential.

METHODS

Diethylaminoethyl (DEAE) ion-exchange chromatography was used to purify the lectin, and SDSPAGE was used to check the purity and homogeneity of the lectin. Spectrometric and chemical analysis were used to characterize the lectin. The anticancer activity of the lectin was examined using in vivo and in vitro functional assays.

RESULTS

A lectin, designated as PgL of 28.0 ± 1.0 kDa molecular mass, was isolated and purified from the pulps of P. granatum and the lectin contains 40% sugar. Also, it is a bivalent ion-dependent lectin and lost its 75% activity in the presence of urea (8M). The lectin agglutinated blood cells of humans and rats, and sugar molecules such as 4-nitrophenyl-α-D-manopyranoside and 2- nitrophenyl -β- D-glucopyranoside inhibited PgL's hemagglutination activity. At pH ranges of 6.0-8.0 and temperature ranges of 30°C -80°C, PgL exhibited the highest agglutination activity. In vitro MTT assay showed that PgL inhibited Ehrlich ascites carcinoma (EAC) cell growth in a dose-dependent manner. PgL exhibited 39 % and 58.52 % growth inhibition of EAC cells in the mice model at 1.5 and 3.0 mg/kg/day (i.p.), respectively. In addition, PgL significantly increased the survival time (32.0 % and 49.3 %) of EAC-bearing mice at 1.5 and 3.0 mg/kg/day doses (i.p.), respectively, in comparison to untreated EAC-bearing animals (p < 0.01). Also, PgL reduced the tumor weight of EAC-bearing mice (66.6 versus 39.13%; p < 0.01) at the dose of 3.0 mg/kg/day treatment. Furthermore, supplementation of PgL restored the haematological parameters toward normal levels deteriorated in EAC-bearing animals by the toxicity of EAC cells.

CONCLUSION

The results indicated that the purified lectin has anticancer activity and has the potential to be developed as an effective chemotherapy agent.

Structural Analysis and Characterization of an Antiproliferative Lectin from Canavalia villosa Seeds

Cells use glycans to encode information that modulates processes ranging from cell-cell recognition to programmed cell death. This information is encoded within a glycocode, and its decoding is performed by carbohydrate-binding proteins. Among these, lectins stand out due to their specific and reversible interaction with carbohydrates. Changes in glycosylation patterns are observed in several pathologies, including cancer, where abnormal glycans are found on the surfaces of affected tissues. Given the importance of the bioprospection of promising biomolecules, the current work aimed to determine the structural properties and anticancer potential of the mannose-specific lectin from seeds of Canavalia villosa (Cvill). Experimental elucidation of the primary and 3D structures of the lectin, along with glycan array and molecular docking, facilitated the determination of its fine carbohydrate-binding specificity. These structural insights, coupled with the lectin's specificity, have been combined to explain the antiproliferative effect of Cvill against cancer cell lines. This effect is dependent on the carbohydrate-binding activity of Cvill and its uptake in the cells, with concomitant activation of autophagic and apoptotic pathways.

Targeted delivery of a short antimicrobial peptide (CM11) against Helicobacter pylori gastric infection using concanavalin A-coated chitosan nanoparticles

Helicobacter pylori is the cause of most cases of stomach ulcers and also causes some digestive cancers. The emergence and spread of antibiotic-resistant strains of H. pylori is one of the most important challenges in the treatment of its infections. The present study aims to develop a concanavalin A (ConA) coated chitosan (CS) nanocarrier-based drug delivery for the targeted release of peptides to the site of H. pylori infection. Accordingly, chitosan was used as an encapsulating agent for CM11 peptide delivery by applying ionotropic gelation method. Con-A was used for coating CS nanoparticles to target H. pylori. The CS NPs and ConA-CS NPs were characterized by FTIR, dynamic light scattering (DLS), and scanning electron microscopy (SEM). The MIC of CM11-loaded ConA-CS NPs against H. pylori SS1 strain was analyzed in vitro. In order to evaluate the treatment efficiency in vivo, a gastric infection model of H. pylori SS1 strain was established in mice and histopathological studies and IL-1β cytokine assay were performed. Based on the results, the size frequency for CS NPs and ConA-CS NPs was about 200 and 350 nm, respectively. The prepared CM11-loaded ConA-CS NPs exhibited antibacterial activity against H. pylori SS1 strain with a concentration of 32 µg/ml. The highest healing process was observed in synthesized CM11-loaded ConA-CS NPs treatments and a significant decrease in IL-1β was observed. Our findings highlight the potential of chitosan nanoparticles as a drug delivery vehicle in the treatment of gastric infection model of H. pylori SS1 strain.

Celecoxib abrogates concanavalin A-induced hepatitis in mice: Possible involvement of Nrf2/HO-1, JNK signaling pathways and COX-2 expression

Concanavalin A (ConA) is an established model for inducing autoimmune hepatitis (AIH) in mice, mimicking clinical features in human. The aimof the current study is to explore the possible protective effect of celecoxib, a cyclooxygenase-2 inhibitor,on immunological responses elicited in the ConA model of acute hepatitis. ConA (20 mg/kg) was administered intravenously to adult male mice for 6 h. Prior to ConA intoxication, mice in the treatedgroups received daily doses of celecoxib (30 and 60 mg/kg in CMC) for 7 days. Results revealed that administration of celecoxib 60 mg/kg for 7 days significantly protected the liver from ConA-induced liver damage revealed by significant decrease in ALT and AST serum levels. Celecoxib 30 and 60 mg/kg pretreatment enhanced oxidant/antioxidant hemostasis by significantreduction of MDA and NO content and increase hepatic GSH contents and SOD activity. In addition, celecoxib 30 and 60 mg/kg caused significant increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and the stress protein heme oxygenase-1 (HO-1) levels. Moreover, celecoxib 30 and 60 mg/kg inhibited the release of proinflammatory markers including IL-1β and TNF-α along with significant decrease in p-JNK, AKT phosphorylation ratio and caspase-3 expression. Besides, Con A was correlated to high expression of cyclooxygenase COX-2 and this increasing was improved by administration of celecoxib. These changes were in good agreement with improvement in histological deterioration. The protective effect of celecoxib was also associated with significant reduction of autophagy biomarkers (Beclin-1 and LC3II). In conclusion, celecoxib showed antioxidant, anti-inflammatory, anti-apoptotic and anti-autophagy activity against Con A-induced immune-mediated hepatitis. These effects could be produced by modulation of Nrf2/HO-1, IL-1B /p-JNK/p-AKT, JNK/caspase-3, and Beclin-1/LC3II signaling pathways.

Expression, purification, characterization, and cytotoxic evaluation of the ML1-STxB fusion protein

Targeted delivery of a toxin substance to cancer cells is one of the most recent cancer treatment options. Mistletoe Lectin-1 (ML1) in Viscum album L. is a Ribosome-inactivating proteins with anticancer properties. Therefore, it appears that a recombinant protein with selective permeability can be generated by fusing ML1 protein with Shiga toxin B, which can bind to Gb3 receptor that is abundantly expressed on cancer cells. In this study, we sought to produce and purify a fusion protein containing ML1 fused to STxB and evaluate its cytotoxic activities. The ML1-STxB fusion protein coding sequence was cloned into the pET28a plasmid, then was transformed into E. coli BL21-DE3 cells. Following induction of protein expression, Ni-NTA affinity chromatography was used to purify the protein. Using SDS-PAGE and western blotting, the expression and purification processes were validated. On the SkBr3 cell line, the cytotoxic effects of the recombinant proteins were evaluated. On SDS-PAGE and western blotting membrane, analysis of purified proteins revealed a band of approximately 41 kDa for rML1-STxB. Ultimately, statistical analysis demonstrated that rML1-STxB exerted significant cytotoxic effects on SkBr3 cells at 18.09 and 22.52 ng/L. The production, purification, and encapsulation of rML1-STxB fusion protein with potential cancer cell-specific toxicity were successful. However, additional research must be conducted on the cytotoxic effects of this fusion protein on other malignant cell lines and in vivo cancer models.

The lectin DrfL inhibits cell migration, adhesion and triggers autophagy-dependent cell death in glioma cells

Glioblastoma multiforme (GBM) is the most aggressive type of glioma, displaying atypical glycosylation pattern that may modulate signaling pathways involved in tumorigenesis. Lectins are glycan binding proteins with antitumor properties. The present study was designed to evaluate the antitumor capacity of the Dioclea reflexa lectin (DrfL) on glioma cell cultures. Our results demonstrated that DrfL induced morphological changes and cytotoxic effects in glioma cell cultures of C6, U-87MG and GBM1 cell lines. The action of DrfL was dependent upon interaction with glycans, and required a carbohydrate recognition domain (CRD), and the cytotoxic effect was apparently selective for tumor cells, not altering viability and morphology of primary astrocytes. DrfL inhibited tumor cell migration, adhesion, proliferation and survival, and these effects were accompanied by activation of p38MAPK and JNK (p46/54), along with inhibition of Akt and ERK1/2. DrfL also upregulated pro-apoptotic (BNIP3 and PUMA) and autophagic proteins (Atg5 and LC3 cleavage) in GBM cells. Noteworthy, inhibition of autophagy and caspase-8 were both able to attenuate cell death in GBM cells treated with DrfL. Our results indicate that DrfL cytotoxicity against GBM involves modulation of cell pathways, including MAPKs and Akt, which are associated with autophagy and caspase-8 dependent cell death.

Nutritional, functional, and bioactive properties of african underutilized legumes

Globally, legumes are vital constituents of diet and perform critical roles in maintaining well-being owing to the dense nutritional contents and functional properties of their seeds. While much emphasis has been placed on the major grain legumes over the years, the neglected and underutilized legumes (NULs) are gaining significant recognition as probable crops to alleviate malnutrition and give a boost to food security in Africa. Consumption of these underutilized legumes has been associated with several health-promoting benefits and can be utilized as functional foods due to their rich dietary fibers, vitamins, polyunsaturated fatty acids (PUFAs), proteins/essential amino acids, micro-nutrients, and bioactive compounds. Despite the plethora of nutritional benefits, the underutilized legumes have not received much research attention compared to common mainstream grain legumes, thus hindering their adoption and utilization. Consequently, research efforts geared toward improvement, utilization, and incorporation into mainstream agriculture in Africa are more convincing than ever. This work reviews some selected NULs of Africa (Adzuki beans (Vigna angularis), African yam bean (Sphenostylis stenocarpa), Bambara groundnut (Vigna subterranea), Jack bean (Canavalia ensiformis), Kidney bean (Phaseolus vulgaris), Lima bean (Phaseolus lunatus), Marama bean (Tylosema esculentum), Mung bean, (Vigna radiata), Rice bean (Vigna Umbellata), and Winged bean (Psophocarpus tetragonolobus)), and their nutritional, and functional properties. Furthermore, we highlight the prospects and current challenges associated with the utilization of the NULs and discusses the strategies to facilitate their exploitation as not only sources of vital nutrients, but also their integration for the development of cheap and accessible functional foods.