Febuxostat mitigates concanavalin A-induced acute liver injury via modulation of MCP-1, IL-1ß, TNF-α, neutrophil infiltration, and apoptosis in mice.

AIM: Liver plays a crucial role in innate immunity reactions. This role predisposes the liver to innate-mediated liver injury when uncontrolled inflammation occurs. In this study, the effect of febuxostat administration on acute liver injury induced by concanavalin A (Con A) injection into mouse eye orbital sinus was studied. MATERIALS AND METHODS: Two doses of febuxostat (10 and 20 mg/kg, orally) were administered either 1 h before or 30 min after the administration of Con A. Febuxostat at a low dose (10 mg/kg) before and after Con A modulated the elevation of serum ALT, liver uric acid, liver myeloperoxidase (MPO), and interleukin-1ß (IL-1ß) induced by Con A. The same dose of febuxostat before Con A also decreased serum total bilirubin and neutrophil infiltration, as evidenced by flow cytometry and histopathological analysis. KEY FINDINGS: Febuxostat at a high dose (20 mg/kg) significantly improved serum ALT, AST, albumin, total bilirubin, liver uric acid, MPO, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4), IL-1ß, and neutrophil infiltration induced by Con A administration. The results of histopathological examination of liver cells paralleled the observed biochemical improvements. Hepatocyte apoptosis as evidenced by immunohistochemical examination of cleaved caspase-3 was markedly decreased in the febuxostat protection and treatment groups, in a dose-dependent manner SIGNIFICANCE: These results indicate that febuxostat, especially at the higher dose, may be an effective inhibitor of immune reactions evoked by Con A administration.

Preparation and characterization of magnetically responsive bacterial polyester based nanospheres for cancer therapy.

Polyhydroxyalkanoates (PHA) are natural, thermoplastic polyesters and due to their biocompatible and biodegradable properties they are good alternatives for the production of scaffolds for engineered tissues or nanoparticles for drug delivery. As a member of polyhydroxyalkanoate family, polyhydroxybutyrates (PHB) have been widely used as a biomaterial for in vitro and in vivo studies since their mechanical properties are very similar to conventional plastics. By using multi-emulsion technique, iron oxide particles were coated with polyhydroxybutyrate (PHB) polymer synthesized from Alcaligenes eutrophus bacteria and the magnetic carrier system was prepared accordingly. The bare nanoparticles and magnetic nanoparticles were morphologically, structurally and magnetically characterized by using Scanning electron microscope (SEM) and Atomic force microscope (AFM); Fourier Transform Infrared Spectrometry (FTIR), and Electron Spin Resonance (ESR) and Vibrating Sample Magnetometer (VSM) techniques, respectively. Particle size of PHB nanoparticles was determined by Zeta Sizer. It was found that the smallest particles were in the range of 239.43 +/- 5.25 nm in diameter. Concanavalin-A (Con-A) was used for targeting the cancer cells while etoposide was used as drug. Con-A and etoposide were loaded onto the particles. Release studies of etoposide were evaluated and the system was optimized for the further in vivo applications. Finally different formulation magnetic PHB nanoparticles cytotoxicity were evaluated in cell culture studies and used HeLa cell line (cervical cancer cells) as a cancer cells and L929 cells (mouse fibroblast cells) as a non-cancer cell line.

Difference in Ulex europaeus agglutinin I-binding activity of decay-accelerating factor detected in the stools of patients with colorectal cancer and ulcerative colitis.

Expression of decay-accelerating factor (DAF, CD55), a complement-regulatory glycoprotein, is enhanced in colorectal-cancer (CC) cells and colonic epithelium in ulcerative colitis (UC), and stools from these patients contain increased amounts of DAF. Carbohydrate chains of glycoproteins are often altered during malignant transformation or inflammation. In this study, we investigated whether DAF molecules in patients with CC and those with UC differ with respect to oligosaccharide side chains. We analyzed DAF in stools and homogenates of colonic-tissue specimens obtained from patients with CC or UC using solid-phase enzyme-linked assay and Western blotting for reactivity with the lectins Ulex europaeus agglutinin I (UEA-I), wheat-germ agglutinin, peanut agglutinin, and concanavalin A. UEA-I bound to DAF in stools from patients with UC but not in that from the stools of CC patients, as demonstrated on the solid-phase enzyme-linked assay (P <.05, Mann-Whitney U test) and Western blotting. Binding of UEA-I was specifically inhibited by the addition of fucose. The difference in UEA-I reactivity with DAF was observed also in colonic-tissue homogenates from patients with UC and those with CC. DAF expressed in the mucosa and excreted into the stools of UC patients is different from that expressed in CC with regard to UEA-I reactivity. Future studies should be directed toward determining whether a qualitatively unique isoform of DAF is present, of which sugar chains are specific to CC in UC patients.

Polyethylene glycol-modified concanavalin A as an effective agent to stimulate anti-tumor cytotoxicity.

The jack bean lectin, concanavalin A (Con A), was modified with 2,4-bis[O-methoxypoly(ethylene glycol)]-6-chloro-s-triazine, activated PEG2, to form PEG-Con A. The immunoreactivity of PEG-Con A towards anti-Con A antibodies was reduced by increasing the degree of modification of amino groups in the Con A molecule. PEG-Con A had a complete reduction of the immunogenicity in mice and prolonged the clearance-time in blood. Although the mitogenic activity of Con A towards murine spleen cells was reduced by the conjugation with activated PEG2, the administration of PEG-Con A to mice enhanced the anti-tumor cytotoxicity of peripheral lymphocytes against melanoma B16 cells.

Vascular permeability in a human tumor xenograft: molecular size dependence and cutoff size.

Molecular size is one of the key determinants of transvascular transport of therapeutic agents in tumors. However, there are no data in the literature on the molecular size dependence of microvascular permeability in tumors. Therefore, we measured microvascular permeability to various macromolecules in the human colon adenocarcinoma LS174T transplanted in dorsal skin chambers in severe combined immunodeficient mice. These molecules were fluorescently labeled and injected i.v. into mice. The microvascular permeability was calculated from the fluorescence intensity measured by the intravital fluorescence microscopy technique. The value of permeability varied approximately 2-fold in the range of molecular weight from 25,000 to 160,000. These data indicate that tumor vessels are less permselective than normal vessels, presumably due to large pores in the vessel wall. The transport of macromolecules appears to be limited by diffusion through these pores. The cutoff size of the pores was estimated by observations of transvascular transport of sterically stabilized liposomes of 100-600 nm in diameter. We found that tumor vessels in our model were permeable to liposomes of up to 400 nm in diameter, suggesting that the cutoff size of the pores is between 400 and 600 nm in diameter.

Inducción de resistencia contra Toxoplasma gondii en ratones NIH tratados con concanavalina A / Induction of resistence against Toxoplasma gondii in NIH mice treated with concanavalin A

Se evaluó el efecto de la administración de concanavalina A (Con A) en ratones expuestos a Toxoplasma gondii. Cuarenta y ocho ratones, cepa NIH (hembras de 22 a 24 g), libres de parásitositos, fueron distribuidos al azar en ocho grupos (A1, A2, B1, B2, C1, C2, D1, D2) de seis animales cada uno. Estos, fueron inoculados por vía intraperitoneal (i.p.) de la siguiente manera: los de los grupos A, B y C recibieron 10, 20 y 40 µg de Con A, respectivamente, mientras que los del grupo D recibieron 0.1 ml de solución salina fisiológica. Todos los ratones fueron confrontados por vía i.p. con 2 LD DE T. gondii, cepa RH. Los de los grupos A1, B1, C1 y D1 fueron expuestos al protozoario dos días después del tratamiento; mientras que los de los grupos A2, B2, C2 y D2, siete días después de éste. Los porcentajes de animales sobrevivientes obtenidos 15 días después de la infección, fueron 16.66, 16.66, 0, 0, 33.33, 50, 16.66 y 0 para los grupos A1, B1, C1, D1, A2, B2, C2 y D2, respectivamente. Para corroborar los resultados obtenidos en los últimos cuatro grupos, se repitió el experimento, después del cual se observaron consecuencias similares, excepto que en el grupo tratado con 40 µg de Con A, se obtuvo una sobrevivencia del 33.33 por ciento. Los datos obtenidos indican que la inyección i.p. de Con A en ratones NIH genera una protección parcial insepecífica contra T. gondii cepa RH, la cual aumenta si se aplican 20 µg del mitógeno siete días antes de la confrontación

Transport of low and high molecular peptides across rabbit Peyer's patches.

The permeability of peptides across rabbit jejunal epithelium (JE) and Peyer's patches (PP) was compared. Kyotorphin (L-tyrosyl-L-arginine) was almost completely hydrolyzed during its membrane transport in both PP and JE, but [D-Arg2]Kyotorphin (L-tyrosyl-D-arginine) was less hydrolyzed in PP than in JE. Since the permeability of intact [D-Arg2]Kyotorphin was almost equal in PP and JE, no superiority of PP to JE was found for dipeptide transport. More intact fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (FITC-BSA) and concanavalin A (FITC-Con A) were transported in PP than in JE. At both absorption sites, the transport of the intact FITC-Con A was superior to that of the intact FITC-BSA. Colchicine significantly reduced the total transport of the intact and degradation forms of both peptides and the reduction ratio was greater in PP than in JE. Accordingly, it was suggested that PP can be used as prominent absorption sites for polypeptides since they have lower peptidase activity and higher endocytosis activity than JE.

[Polysaccharides in fungi. XXV. Biological activities of two galactomannans from the insect-body portion of Chán hua (fungus: Cordyceps cicadae)].

Biological activities of two galactomannans (CI-P and CI-A) isolated from the insectbody portion of Chán hua (fungus: Cordyceps cicadae) were studied. CI-P having low affinity for concanavalin A (Con A) exhibited potent carbon-clearance activity in mouse, although both polysaccharides had little antitumor activity against sarcoma 180 in mice. Furthermore, CI-P and CI-A was found to have potent hypoglycemic activity in normal mice, and CI-A having high affinity for Con A showed slightly higher activity than CI-P.

A differentiation-defective concanavalin-A-resistant variant of a pluripotent embryonal carcinoma cell line.

A concanavalin-A(Con A)-resistant variant of the pluripotent mouse embryonal carcinoma cell line, PSA1-NG2, was isolated. This variant, designated NG2-2.16, fails to exhibit the extensive spontaneous differentiation displayed by PSA1-NG2 in colonies in vitro and in tumours in vivo. The molecular nature of the defect in NG2-2.16 cells was not revealed by quantitative studies of the binding, uptake and metabolism of tritiated Con A, or by Western blotting of membrane and whole cell homogenates, thus indicating the defect to be the result of a more subtle molecular alteration. Statistical evidence suggests that the same mutation is responsible for both the Con A resistance and the lack of spontaneous differentiation. NG2-2.16 cells were induced to differentiate by exposure to retinoic acid, suggesting that the mutation affects the regulation of differentiation rather than the potential for differentiation.