Effect of safflower oil (Carthamus tinctorius L.) supplementation in the abdominal adipose tissues and body weight of male Wistar rats undergoing exercise training.

This study aimed to evaluate the effects of safflower oil supplementation on the metabolic parameters, body weight, and abdominal adiposity in male Wistar rats fed with a high-fat diet (HFD) while undergoing exercise training. The rats were assigned to four groups: standard diet and sedentary (SDS), high-fat diet and sedentary (HFDS), high-fat diet and training (HFDT), and high-fat diet, training, and safflower oil (HFDTSO) groups. HFD significantly increased the abdominal adiposity in male Wistar rats. The safflower oil had no effect on the body weight and levels of blood glucose, TG, and TC, but it significantly reduced abdominal adiposity in male Wistar rats fed with an HFD while undergoing exercise training. Safflower oil supplementation reduced the abdominal fat in rats undergoing swimming training.

Lectin obtained from the red seaweed Bryothamnion triquetrum: Secondary structure and anti-inflammatory activity in mice.

Seaweeds are sources of biomolecules with biological activities and pharmacological potential - for example, lectins, a group of proteins that can bind reversibly to carbohydrates or compounds containing them. The aim of this study was to elucidate the structural properties of a lectin extracted from the red seaweed Bryothamnion triquetrum (BtL) and to investigate its anti-inflammatory activity in mice. The lectin was purified by precipitation with ammonium sulfate and ion-exchange chromatography. Its secondary structure and tryptophan (Trp) microenvironment were analyzed by circular dichroism spectroscopy and steady-state fluorescence spectroscopy, respectively. The anti-inflammatory effect was evaluated by means of paw edema induced by carrageenan or dextran, myeloperoxidase activity in paw tissue, and by measurement of leukocyte and neutrophil migration and cytokine quantification in a peritonitis model. The secondary structure of BtL is mostly composed of ß-strands and unordered conformation, and it is quite resistant to extremes of pH and temperature, preserving the exposure of Trp residues under these conditions. In an assessment of biological activities, groups of mice were subjected to pretreatment with BtL before the inflammatory stimulus. BtL had anti-inflammatory effects in the models tested, and hence may be considered a molecule with potential to be used in the pharmaceutical industry.

Role of the route of leukotrienes in an experimental model of oral mucositis induced by 5-fluorouracil 1.

PURPOSE: To investigate the participation of cysteinyl leukotrienes in the pathophysiology of oral mucositis. METHODS: Oral mucositis was induced in hamsters using 5-fluorouracil (5-FU; 60 and 40 mg/kg; i.p., on days 1 and 2, respectively, and with excoriations in jugal mucosa on day 4). Montelukast (10, 20, or 40 mg/kg/d; gavage), MK886 (3 mg/kg/d, i.p.), or saline or celecoxib (7.5 mg/kg/d; i.p.) was administered 1 h prior to 5-FU and daily, until the fourth (MK886) or tenth day, when the animals were euthanized and their jugal mucosa was collected for macroscopic, histopathological, and immunohistochemical evaluation. RESULTS: Neither montelukast nor MK-886 prevented the oral mucositis induced by 5-FU, as observed by histopathological evaluation. In addition, we did not find significant differences in the expression of inducible nitric oxide synthase-2, cyclooxygenase-2, or interleukin (IL)-1ß between the experimental and control groups. However, we did observe a significant decrease in tumor necrosis factor (TNF)-α expression for all doses of montelukast; we also observed a significant decrease in IL-10 with 40 mg/kg/d and MK 886. CONCLUSIONS: Cysteinyl leukotrienes do not play an important role in experimental oral mucositis induced by 5-FU. There is a modulating action specifically on TNF-α.

Role of the route of leukotrienes in an experimental model of oral mucositis induced by 5-fluorouracil

Abstract Purpose: To investigate the participation of cysteinyl leukotrienes in the pathophysiology of oral mucositis. Methods: Oral mucositis was induced in hamsters using 5-fluorouracil (5-FU; 60 and 40 mg/kg; i.p., on days 1 and 2, respectively, and with excoriations in jugal mucosa on day 4). Montelukast (10, 20, or 40 mg/kg/d; gavage), MK886 (3 mg/kg/d, i.p.), or saline or celecoxib (7.5 mg/kg/d; i.p.) was administered 1 h prior to 5-FU and daily, until the fourth (MK886) or tenth day, when the animals were euthanized and their jugal mucosa was collected for macroscopic, histopathological, and immunohistochemical evaluation. Results: Neither montelukast nor MK-886 prevented the oral mucositis induced by 5-FU, as observed by histopathological evaluation. In addition, we did not find significant differences in the expression of inducible nitric oxide synthase-2, cyclooxygenase-2, or interleukin (IL)-1β between the experimental and control groups. However, we did observe a significant decrease in tumor necrosis factor (TNF)-α expression for all doses of montelukast; we also observed a significant decrease in IL-10 with 40 mg/kg/d and MK 886. Conclusions: Cysteinyl leukotrienes do not play an important role in experimental oral mucositis induced by 5-FU. There is a modulating action specifically on TNF-α.

Side-Effects of Irinotecan (CPT-11), the Clinically Used Drug for Colon Cancer Therapy, Are Eliminated in Experimental Animals Treated with Latex Proteins from Calotropis procera (Apocynaceae).

Intestinal mucositis (IM) is the critical side effect of irinotecan (CPT-11), which is the front-line drug used for the treatment of colorectal cancer. This study aimed to evaluate the effectiveness of latex proteins (LP) from Calotropis procera to prevent IM and diarrhea in animals. Swiss mice were treated daily with saline or LP (1, 5, or 50 mg/kg, i.v.) 24 h prior to CTP-11 (75 mg/kg/4 days, i.p) and for additional 6 days. Animal survival, body weight variation, and diarrhea were registered. After animal sacrifice (day 7 post first injection of CPT-11), intestinal samples were collected to study morphology and inflammatory parameters. Animals given LP exhibited improved parameters (survival, body weight, and absence of diarrhea) as compared with the CPT-11 control. The severity of IM observed in animals given CPT-11 was reduced in animals treated with LP. Treatment with LP also prevented the reduction in the villus/crypt ratio promoted by CPT-11. The rise in MPO activity and pro-inflammatory cytokines, over-contractility of the smooth muscle, and diarrhea were all abrogated in LP-treated mice. Markedly reduced immunostaining intensity for COX-2, TNF-α, IL-1ß, iNOS, and NF-κB was observed in the intestinal tissue of animals treated with LP. The side-effects of CPT-11 were eliminated by LP treatment in experimental animals and improved clinical parameters characteristic of IM All known biochemical pathogenesis. Copyright © 2016 John Wiley & Sons, Ltd.

Chemotherapy-associated steatohepatitis induced by irinotecan: a novel animal model.

PURPOSE: Nonalcoholic steatohepatitis (NASH) has been associated with irinotecan (IRI)-based cancer chemotherapy regimens. The purpose of this study was to propose and test a consistent model of IRI-induced NASH, filling a gap in the medical literature. METHODS: Swiss male mice were distributed in groups (n = 8) and injected with saline (5 mL/kg, i.p.; control) or IRI (25, 50, 75 or 100 mg/kg, i.p.) thrice a week for 7 weeks. Blood samples were collected to measure the serum concentrations of proteins, alanine and aspartate aminotransferases (ALT and AST). Each week animals were euthanized, and the livers were submitted to myeloperoxidase (MPO) assay, lipid dosage, immunohistochemistry for inducible nitric oxide synthase (iNOS), TNF-α and interleukin-1ß (IL-1ß), and histopathological analysis. Survival rates were also determined. RESULTS: Mice treated with IRI had a significantly (p < 0.05) lower survival rate than controls and time- and dose-dependent body weight loss. ALT and AST plasma levels increased in relation to controls only in mice receiving IRI 50 mg/kg (p < 0.05). The histopathological features characteristic of NASH was observed, including steatosis, lobular neutrophil infiltration and ballooning hepatocytic degeneration. Additional findings included increased MPO, lipid accumulation, portal neutrophil infiltration, IL-1ß and iNOS expression and fibrosis in liver tissues and low serum protein levels compared to controls. CONCLUSION: This is the first report of a consistent model of IRI-induced NASH capable of mimicking clinical findings.

Anti-inflammatory effect of a sulphated polysaccharide fraction extracted from the red algae Hypnea musciformis via the suppression of neutrophil migration by the nitric oxide signalling pathway.

OBJECTIVES: The aim of this study was to evaluate the anti-inflammatory effect of a sulphated polysaccharide fraction (PLS) extracted from the alga Hypnea musciformis and investigate the possible involvement of the nitric oxide (NO) pathway in this effect. METHODS: The anti-inflammatory activity of PLS was evaluated using inflammatory agents (carrageenan and dextran) to induce paw oedema and peritonitis in Swiss mice. Samples of paw tissue and peritoneal fluid were removed to determine myeloperoxidase (MPO) activity, NO3 /NO2 levels, and interleukin-1ß (IL-1ß) level. The involvement of NO in the modulation of neutrophil migration in carrageenan-induced paw oedema or peritonitis was also investigated. KEY FINDINGS: Compared with vehicle-treated mice, mice pretreated with PLS (10 mg/kg) inhibited carrageenan-induced and dextran-induced oedema; it also inhibited total and differential peritoneal leucocyte counts in a model of peritonitis. These PLS effects were reversed by l-arginine treatment and recovered with the administration of a NO synthase blocker (aminoguanidine). Furthermore, PLS reduced the MPO activity, decreased IL-1ß levels, and increased NO3 /NO2 levels in the peritoneal cavity. CONCLUSIONS: PLS reduced the inflammatory response by modulating neutrophil migration, which appeared to be dependent on the NO pathway.

Antiinflammatory and antinociceptive effects in mice of a sulfated polysaccharide fraction extracted from the marine red algae Gracilaria caudata.

Many algal species contain relatively high concentrations of polysaccharide substances, a number of which have been shown to have anti-inflammatory and/or immunomodulatory activity. In this study, we evaluated the anti-inflammatory and antinociceptive effects in mice of a sulfated polysaccharide fraction (PLS) extracted from the algae Gracilaria caudata. The antiinflammatory activity of PLS was evaluated using several inflammatory agents (carrageenan, dextran, bradykinin, and histamine) to induce paw edema and peritonitis in Swiss mice. Samples of the paw tissue and peritoneal fluid were removed to determine myeloperoxidase (MPO) activity or TNF-α and IL-1ß levels, respectively. Mechanical hypernociception was induced by subcutaneous injection of carrageenan into the plantar surface of the paw. Pretreatment of mice by intraperitoneal administration of PLS (2.5, 5, and 10 mg/kg) significantly and dose-dependently reduced carrageenan-induced paw edema (p < 0.05) compared to vehicle-treated mice. Similarly, PLS 10 mg/kg effectively inhibited edema induced by dextran and histamine; however, edema induced by bradykinin was unaffected by PLS. PLS 10 mg/kg inhibited total and differential peritoneal leukocyte counts following carrageenan-induced peritonitis. Furthermore, PLS reduced carrageenan-increased MPO activity in paws and reduced cytokine levels in the peritoneal cavity. Finally PLS pretreatment also reduced hypernociception 3-4 h after carrageenan. We conclude that PLS reduces the inflammatory response and hypernociception in mice by reducing neutrophil migration and cytokines concentration.

Discoidin I from Dictyostelium discoideum and Interactions with oligosaccharides: specificity, affinity, crystal structures, and comparison with discoidin II.

Discoidin I (DiscI) and discoidin II (DiscII) are N-acetylgalactosamine (GalNAc)-binding proteins from Dictyostelium discoideum. They consist of two domains: an N-terminal discoidin domain and a C-terminal H-type lectin domain. They were cloned and expressed in high yield in recombinant form in Escherichia coli. Although both lectins bind galactose (Gal) and GalNAc, glycan array experiments performed on the recombinant proteins displayed strong differences in their specificity for oligosaccharides. DiscI and DiscII bind preferentially to Gal/GalNAcbeta1-3Gal/GalNAc-containing and Gal/GalNAcbeta1-4GlcNAcbeta1-6Gal/GalNAc-containing glycans, respectively. The affinity of the interaction of DiscI with monosaccharides and disaccharides was evaluated using isothermal titration calorimetry experiments. The three-dimensional structures of native DiscI and its complexes with GalNAc, GalNAcbeta1-3Gal, and Galbeta1-3GalNAc were solved by X-ray crystallography. DiscI forms trimers with involvement of calcium at the monomer interface. The N-terminal discoidin domain presents a structural similarity to F-type lectins such as the eel agglutinin, where an amphiphilic binding pocket suggests possible carbohydrate-binding activity. In the C-terminal H-type lectin domain, the GalNAc residue establishes specific hydrogen bonds that explain the observed affinity (K(d)=3x10(-4) M). The different specificities of DiscI and DiscII for oligosaccharides were rationalized from the different structures obtained by either X-ray crystallography or molecular modeling.

Structure determination of Discoidin II from Dictyostelium discoideum and carbohydrate binding properties of the lectin domain.

The social amoeba Dictyostelium discoideum adopts a cohesive stage upon starvation and then produces Discoidin I and II, two proteins able to bind galactose and N-acetyl-galactosamine. The N-terminal domain or discoidin domain (DS) is widely distributed in eukaryotes where it plays a role in extracellular matrix binding while the C-terminal domain displays sequence similarities to invertebrate lectins. We present the first X-ray structures of the wild-type and recombinant Discoidin II in unliganded state and in complex with monosaccharides. The protein forms a homotrimer which presents two binding surfaces situated on the opposite boundaries of the structure. The binding sites of the N-terminal domain contain PEG molecules that could mimics binding of natural ligand. The C-terminal lectin domain interactions with N-acetyl-D-galactosamine and methyl-beta-galactoside are described. The carbohydrate binding sites are located at the interface between monomers. Specificity for galacto configuration can be rationalized since the axial O4 hydroxyl group is involved in several hydrogen bonds with protein side chains. Titration microcalorimetry allowed characterization of affinity and demonstrated the enthalpy-driven character of the interaction. Those results highlight the structural differentiation of the DS domain involved in many cell-adhesion processes from the lectin activity of Dictyostelium discoidins.

Purification and biological effects of Araucaria angustifolia (Araucariaceae) seed lectin.

This paper describes the purification and characterization of a new N-acetyl-d-glucosamine-specific lectin from Araucaria angustifolia (AaL) seeds (Araucariaceae) and its anti-inflammatory and antibacterial activities. AaL was purified using a combination of affinity chromatography on a chitin column and ion exchange chromatography on Sephacel-DEAE. The pure protein has 8.0kDa (SDS-PAGE) and specifically agglutinates rabbit erythrocytes, effect that was independent of the presence of divalent cations and was inhibited after incubation with glucose and N-acetyl-d-glucosamine. AaL showed antibacterial activity against Gram-negative and Gram-positive strains, shown by scanning electron microscopy. AaL, intravenously injected into rats, showed anti-inflammatory effect, via carbohydrate site interaction, in the models of paw edema and peritonitis. This lectin can be used as a tool for studying bacterial infections and inflammatory processes.