Purification, characterisation, and carbohydrate specificity of the lectin of Ficus cunia

Ficus cunia Buch.-Ham. ex Roxb. (leaves): An experimental evaluation of the cytotoxicity, thrombolytic, analgesic and neuropharmacological activities of its methanol extract

Background The aim of this experiment was to evaluate the cytotoxic, thrombolytic, analgesic, sedative-hypnotic and anxiolytic activities of the methanolic extract of Ficus cunia leaves. Methods Primary phytochemical screening was accomplished by using established methods. Cytotoxicity was studied by brine shrimp lethality test, and the thrombolytic assay was conducted through clot lysis method with human blood. The in vivo action was done using mice of both sexes. The analgesic activity was evaluated by acetic acid-induced writhing test and formalin-induced paw licking test. Open field, hole cross and thiopental Na-induced sleeping time test were used to examine the sedative-hypnotic activity, and elevated plus maze (EPM) and hole board test were used to identify the anxiolytic activity. Results The results elicited that the extract contained several phytochemicals such as alkaloid, flavonoid, and tannin. The extract was found to have a median lethal concentration (LC50) value of 55.48 μg/mL in the brine shrimp lethality bioassay. It was also assessed for antithrombotic activity when compared with streptokinase; it has significant (p < 0.001) thrombolytic effect (34.72 ± 1.74%) contrasted with standard streptokinase (67 ± 1.56%). The extract at doses of 200 and 400 mg/kg produced inhibition of 32.58% and 46.63% in acetic acid-induced pain and 45.88 and 61.18% in formalin-induced pain. The sedative and hypnotic activities on the central nervous system of the methanol extract of F. cunia (MEFC) leaves were evaluated. The extract delivered critical sedative impact at the doses of 200 and 400 mg/kg (by oral route) treated with reference to the substance diazepam, and the hypnotic impact was also observed in the case of mice. MEFC at its maximum dose (400 mg/kg) significantly (p < 0.01) increased the time spent in the open arms of the EPM. In the hole board test, there was a dose-dependent (at 200 and 400 mg/kg) and a significant (p < 0.05 and p < 0.01) increase in the number of head pokes in comparison to control. Conclusions The results of the present study gave a helpful baseline in progression for the possible use of MEFC as a cytotoxic, thrombolytic, analgesic, sedative-hypnotic and anxiolytic drug.

Purification and characterisation of a pronase-inducible lectin isolated from human serum

A new lectin was purified to electrophoretic homogeneity from pronase treated human serum by a single-step of affinity chromatography on concanavalin A-Sepharose 4B. The isolated lectin agglutinated five types of vertebrate RBC, with highest titer against hen RBC. This activity was independent of divalent cations, insensitive to EDTA and specific to mannosamine, glucosamine as well as galactosamine. Purified lectin gave a single symmetrical peak in its native form with a molecular mass estimate of 6kDa in FPLC analysis and 6.5kDa by MALDI-TOF MS. SDS-PAGE analysis of the lectin revealed that it is a homo-oligomer of a 3kDa subunit protein. Isolated lectin did possess both, hemagglutinating and phenoloxidase activities, but did not exhibit any antibacterial or antifungal activities. In addition, this lectin could oxidize all nine different phenolic substrates tested, with hydroquinone proving to be the best among them. Phenoloxidase inhibitors namely, phenylthiourea and tropolone inhibited this oxidation activity.

Ficus spp. (fig): ethnobotany and potential as anticancer and anti-inflammatory agents

This review explores medieval, ancient and modern sources for ethnopharmacological uses of Ficus (fig) species, specifically for employment against malignant disease and inflammation. The close connection between inflammatory/infectious and cancerous diseases is apparent both from the medieval/ancient merging of these concepts and the modern pharmacological recognition of the initiating and promoting importance of inflammation for cancer growth. Also considered are chemical groups and compounds underlying the anticancer and anti-inflammatory actions, the relationship of fig wasps and fig botany, extraction and storage of fig latex, and traditional methods of preparing fig medicaments including fig lye, fig wine and medicinal poultices.

Characterization of a galactose binding serum lectin from the Indian catfish, Clarias batrachus: possible involvement of fish lectins in differential recognition of pathogens

A lectin with molecular mass around 200 kDa was isolated from the serum of the Indian catfish Clarias batrachus. The bioactivity of this serum lectin was Ca2+ and pH dependent. The lectin appeared to be specific for alpha-methyl galactose and sialoglycoproteins like porcine and bovine submaxillary mucin and could agglutinate human, rabbit, mice, rat and chicken erythrocytes. This fish lectin was able to specifically agglutinate different gram negative bacteria. When it was checked against different strains of the fish pathogen Aeromonas sp., it significantly altered the viability and pathogenicity of the bacteria. Binding of the lectin to Aeromonas sp., resulted in a dose dependent increase in the bactericidal activity of fish macrophages. However, when the lectin was checked against different gram positive bacteria it could not agglutinate or affect the viability of those strains and also failed to bring about any significant change in the bactericidal potential of fish macrophages. The lectin was able to induce the proliferation of head kidney lymphocytes of Clarias and helped in the release of 'IL-1' like cytokines from head kidney macrophages.

Mucin binding mitogenic lectin from freshwater Indian gastropod Belamyia bengalensis: purification and molecular characterization

A lectin was purified from the hemolymph of the freshwater Indian gastropod Belamyia bengalensis. The purification involved successive ion-exchange chromatography on Resource Q and gel filtration on Superose 12 column in FPLC system. Homogeneity of the protein was confirmed by polyacrylamide gel electrophoresis. Belamyia bengalensis lectin (BBL) was a monomeric protein with a molecular weight of 33 kDa as demonstrated by gel filtration and SDS-PAGE. It is a glycoprotein containing 6% total sugar and its activity is highly dependent on Ca(2+). BBL agglutinated human erythrocytes and is a blood group non-specific lectin. It agglutinated animal erythrocytes also. Hapten inhibition studies indicated that BBL shows binding specificity only for N-acetyl-D-glucosamine and N-acetyl-D-galactosamine at a high concentration among the mono- and oligosaccharides tested. Among the glycoproteins used for hemagglutination-inhibition assay, porcine submaxillary mucin was found to be the best inhibitor. Chemical modification studies indicated that Lys, Arg, and Trp are essential for the sugar-binding activity of BBL. Circular dichroism spectra revealed high content of alpha-helical structure in the lectin. BBL is a potent mitogen as it stimulated the T-lymphocyte proliferation, specifically the Th1 subset.

The glycosylated enzyme-binding assay for the study of the interaction of free and immobilized lectins with carbohydrates

The glycosylated enzymes (invertase and glucose oxidase) were used as the competitive markers for a simple and rapid determination of the lectin-saccharide interactions. The method, based on the formation of the conjugate of an appropriate glycoenzyme with the specific carbohydrate-binding lectins and the inhibition of the conjugate formation with a monosaccharide, was described. This method was used to estimate the relative carbohydrate specificity of Concanavalin A for monosaccharides derived from D-mannose. The inhibition effect of the saccharides on the formation of Concanavalin A-glycosylated enzyme precipitate was compared with their influence on the enzyme sorption on conjugate Concanavalin A-bead cellulose support. The amount of the interacting enzyme was estimated either indirectly from its concentration in a supernatant that was determined spectrophotometrically (Con A was in a free or immobilized form) or directly in the immobilized form linked to Con A-sorbent using the flow microcalorimetric method. The results obtained, using different methods, agreed in general.

Purification and characterization of an N-acetyllactosamine-specific lectin from tubers of Arum maculatum

A lectin was purified from the tubers of Arum maculatum (family Araceae) by affinity chromatography on a thyroglobulin-Sepharose column. The lectin is not a glycoprotein and has a subunit molecular weight of 14,600. It is specifically inhibited by N-acetyllactosamine (Gal beta 1,4GlcNAc), but is not significantly inhibited by monosaccharides or by lactose (Gal beta 1,4Glc), lacto-N-biose 1 (Gal beta 1,3GlcNAc), or chitobiose (GlcNAc beta 1,4GlcNAc). Asialoglycoproteins which contain N-acetyllactosamine structures are even more effective inhibitors of the lectin. This lectin should be a useful probe for N-acetyllactosamine groups in glycoproteins.