Lectin Isolated from Japanese Red Sword Beans (Canavalia gladiata) as a Potential Cancer Chemopreventive Agent

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.

Exploring the Phytochemicals and Anti-Cancer Potential of the Members of Fabaceae Family: A Comprehensive Review

Cancer is the second-ranked disease and a cause of death for millions of people around the world despite many kinds of available treatments. Phytochemicals are considered a vital source of cancer-inhibiting drugs and utilize specific mechanisms including carcinogen inactivation, the induction of cell cycle arrest, anti-oxidant stress, apoptosis, and regulation of the immune system. Family Fabaceae is the second most diverse family in the plant kingdom, and species of the family are widely distributed across the world. The species of the Fabaceae family are rich in phytochemicals (flavonoids, lectins, saponins, alkaloids, carotenoids, and phenolic acids), which exhibit a variety of health benefits, especially anti-cancer properties; therefore, exploration of the phytochemicals present in various members of this family is crucial. These phytochemicals of the Fabaceae family have not been explored in a better way yet; therefore, this review is an effort to summarize all the possible information related to the phytochemical status of the Fabaceae family and their anti-cancer properties. Moreover, various research gaps have been identified with directions for future research.

Cloning, Characterization, Expression Analysis, and Agglutination Studies of Novel Gene Encoding β-D-Galactose, N-Acetyl-D-Glucosamine and Lactose-Binding Lectin from Rice Bean (Vigna umbellata)

Lectins are glycoproteins and known for their peculiar carbohydrate-binding activity and their insect-pest-resistant properties. Earlier we have published our research finding on novel gene encoding Bowman-Birk type protease inhibitor with insecticidal properties from rice bean. This paper presents first report on cloning, sequencing, and expression of RbL ORF of 843 bp encoding 280 amino acids long lectin precursor from rice bean (Vigna umbellata) seeds. Blast analysis revealed more than 90% similarity of RbL protein with Vigna aconitifolia and Vigna angularis lectins. Phylogenetic analysis also revealed a close relationship between RbL and other legume lectins. Sequence analysis of genomic DNA revealed intronless nature of RbL gene (GenBank accession No. MT043160). The isolated RbL ORF was expressed in E. coli BL-21(DE3) cells and maximum expression was recorded with 0.5 mM IPTG after 4 h incubation at 37 °C. Western blotting confirmed RbL protein expression in E. coli. Recombinant protein (His₆-RbL) of ~ 35 kDa m.wt was purified using Ni-NTA affinity chromatography to the extent of 0.26 mg/ml. In silico analysis characterized RbL protein as acidic, stable, hydrophobic, and secretary protein with one signal peptide cleavage site (A₂₆-A₂₇) and four N-glycosylation sites. Template-based 3D model of RbL was structured using MODELLER tool and validated as good quality model. Structural analysis revealed dominance of β-pleated sheets and β-turns in RbL protein structure. β-D-galactose, N-acetyl-D-glucosamine, and lactose were predicted as putative ligands for RbL protein. Hydrogen bonding and hydrophobic forces were the major interactions between the predicted ligands and RbL protein. Agglutination and agglutination inhibition assays confirmed the binding specificity of RbL protein with the trypsinized rabbit erythrocytes and with the predicted ligands, respectively. Gene ontology analysis functionally annotated RbL protein as a plant defense protein. The novel information generated in the study is not mere pre-experimental findings but could also lay foundation for future research on exploring RbL gene and encoding protein for different biomedical and biotechnological applications.

Edible Sword Bean Extract Induces Apoptosis in Cancer Cells In Vitro and Inhibits Ascites and Solid Tumor Development In Vivo

Antitumor potential of edible sword bean (Canavalia gladiata (L.)) extract has been evaluated against Daltons lymphoma ascites (DLA) using in vitro and in vivo studies. Methanolic extraction was carried out and in vitro studies were performed against both DLA and A549, lung cancer cell lines. The results revealed that sword bean extract inhibited cell growth and induced apoptosis as evidenced by cytotoxic assay, Hoechst 33342 staining and acridine orange/ethidium bromide dual staining. In vivo studies performed on DLA induced solid as well as ascitic tumors models showed administration of sword bean extract (10 mg/kg B.wt.) could significantly inhibit ascitic and solid tumor development in mice. Therefore, our overall results revealed that C. gladiata treatment could significantly inhibit tumor development and induce apoptosis in tumor cells.