Annexin-A1 peptide down-regulates the leukocyte recruitment and up-regulates interleukin-10 release into lung after intestinal ischemia-reperfusion in mice

Background: Intestinal ischemia/reperfusion (IR) injury is a serious and triggering event in the development of remote organ dysfunction, from which the lung is the main target. This condition is characterized by intense neutrophil recruitment, increased microvascular permeability. Intestinal IR is also responsible for induction of adult respiratory distress syndrome, the most serious and life-threatening form of acute lung injury. The purpose of this study was to investigate the effect of annexin-A1 protein as an endogenous regulator of the organ remote injury induced by intestinal ischemia/reperfusion. Male C57bl/6 mice were subjected to intestinal ischemia, induced by 45 min occlusion of the superior mesenteric artery, followed by reperfusion. Results: The intestinal ischemia/reperfusion evoked a high intensity lung inflammation as indicated by the number of neutrophils as compared to control group. Treatment with annexin-A1 peptidomimetic Ac2-26, reduced the number of neutrophils in the lung tissue and increased its number in the blood vessels, which suggests a regulatory effect of the peptide Ac2-26 in the neutrophil migration. Moreover, the peptide Ac2-26 treatment was associated with higher levels of plasma IL-10. Conclusion: Our data suggest that the annexin-A1 peptidomimetic Ac2-26 treatment has a regulatory and protective effect in the intestinal ischemia/reperfusion by attenuation of the leukocyte migration to the lung and induction of the anti-inflammatory cytokine IL-10 release into the plasma. The anti-inflammatory action of annexin-A1 and its peptidomimetic described here may serve as a basis for future therapeutic approach in mitigating inflammatory processes due to intestinal ischemia/reperfusion. © 2013 Guido et al.; licensee BioMed Central Ltd.

Protective effect of mannan oligosaccharides against early colonization by Salmonella Enteritidis in chicks is improved by higher dietary threonine levels

Aims: To evaluate mannan oligosaccharide (MOS) and threonine effects on performance, small intestine morphology and Salmonella spp. counts in Salmonella Enteritidis-challenged birds. Methods and Results: One-day-old chicks (1d) were distributed into five treatments: nonchallenged animals fed basal diet (RB-0), animals fed basal diet and infected with Salmonella Enteritidis (RB-I), animals fed high level of threonine and infected (HT-I), birds fed basal diet with MOS and infected (MOS-I), birds fed high level of threonine and MOS and infected (HT+MOS-I). Birds were inoculated at 2d with Salmonella Enteritidis, except RB-0 birds. Chicks fed higher dietary threonine and MOS showed performance similar to RB-0 and intestinal morphology recovery at 8 dpi. Salmonella counts and the number of Salmonella-positive animals were lower in HT+MOS-I compared with other challenged groups. Conclusion: Mannan oligosaccharides and threonine act synergistically, resulting in improved intestinal environment and recovery after Salmonella inoculation. Significance and Impact of the Study: Nutritional approaches may be useful to prevent Salmonella infection in the first week and putative carcass contamination at slaughter. This is the first report on the possible synergistic effect of mannan oligosaccharides and threonine, and further studies should be performed including performance, microbiota evaluation, composition of intestinal mucins and immune assessment. © 2012 The Society for Applied Microbiology.

Alterations in the duodenum myenteric neurons of Wistar rats after ingesting of 2,4 dichlorophenoxyacetic acid

The 2,4 dichlorophenoxyacetic acid (2,4-D) is a systemic herbicide whose effects in animal organic systems have been examined in previous studies, being the neurotoxicity considered the predominant effect. However, the studies that detect the 2,4-D neurotoxicity have merely focused in the central nervous system, and therefore, little is known about the effect of this herbicide in the enteric nervous system. This study aimed to verifying the 2,4-D effects on the myenteric neurons in duodenum of Wistar rats. Ten 60-day-old male Wistar rats (Rattus norvegicus) were divided in two groups: control group (C) that did not receive 2,4-D and experimental group (E) that received 5.0 mg of 2,4-D/kg for 15 days. At the end of experimental period, the animal were euthanized, the duodenum was collected and processed for NADPH-diaphorase histochemical analysis in order to expose the nitrergic myenteric neurons (NADPH-dp). In the light microscopy analysis, the whole-mount preparation obtained from duodenum of each animal were image-captured in 120 and 40 fields, for quantitative and morphometric analyses of myenteric neurons, respectively. The neuronal density was not affected when comparing the two groups, but an increase (p > 0.05) of 8.5% was observed in the cell body area of neurons in the E group. In conclusion, the ingestion of 2,4-D at a dosage of 5.0 mg/kg body weight for 15 days does not change the neuronal density, but promotes the hypertrophy of NADPH-dp myenteric neurons in duodenum of the rats of this study.

A metabolic pathway assembled by enzyme selection may support herbivory of leaf-cutter ants on plant starch

Mutualistic associations shape the evolution in different organism groups. The association between the leaf-cutter ant Atta sexdens and the basidiomycete fungus Leucoagaricus gongylophorus has enabled them to degrade starch from plant material generating glucose, which is a major food source for both mutualists. Starch degradation is promoted by enzymes contained in the fecal fluid that ants deposit on the fungus culture in cut leaves inside the nests. To understand the dynamics of starch degradation in ant nests, we purified and characterized starch degrading enzymes from the ant fecal fluid and from laboratory cultures of L. gongylophorus and found that the ants intestine positively selects fungal α-amylase and a maltase likely produced by the ants, as a negative selection is imposed to fungal maltase and ant α-amylases. Selected enzymes are more resistant to catabolic repression by glucose and proposed to structure a metabolic pathway in which the fungal α-amylase initiates starch catalysis to generate byproducts which are sequentially degraded by the maltase to produce glucose. The pathway is responsible for effective degradation of starch and proposed to represent a major evolutionary innovation enabling efficient starch assimilation from plant material by leaf-cutters. © 2013 Elsevier Ltd.

Lack of protective effects of zinc gluconate against rat colon carcinogenesis

Zinc has been proposed as a promising chemopreventive candidate against colon cancer. However, few studies on the potential beneficial effects of this trace element on cancer chemoprevention are available. The present study was designed to investigate the potential modifying influence of zinc gluconate (ZnGly) on the initiation step of colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH). Male Wistar rats received orally ZnGly (15 mg elemental zinc/kg, 3 times per wk) 2 wk before and during DMH treatment (3 × 40 mg/kg, once a wk). The animals were euthanized at the end of 4th and 16th wk. Colons were analyzed for aberrant crypt foci (ACF) and tumor development. Blood and colon zinc levels, cell proliferation, and apoptosis indexes in colonic crypts were analyzed 24 h after the last DMH administration. Oral treatment with ZnGly did neither alter the number of ACF nor the indexes of cell proliferation and apoptosis in the colonic mucosa. The incidence and multiplicity of colon tumors induced by DMH and their histopathological patterns were not modified by previous treatment with ZnGly. These findings indicate a lack of chemopreventive action of zinc gluconate supplementation on the initiation step of rat colon carcinogenesis induced by DMH. © 2013 Copyright Taylor and Francis Group, LLC.

Enzyme use in kibble diets formulated with wheat bran for dogs: Effects on processing and digestibility

Recently, there is an interest in technologies that favour the use of coproducts for animal nutrition. The effect of adding two enzyme mixtures in diets for dogs formulated with wheat bran (WB) was evaluated. Two foods with similar compositions were formulated: negative control (NC; without WB) and test diet (25% of WB). The test diet was divided into four treatments: without enzyme (positive control), enzyme mixture 1 (ENZ1; added before extrusion β-glucanase, xylanase, cellulase, glucoamylase, phytase); enzyme mixture 2 (ENZ2; added before extrusion the ENZ1 more α-amylase); enzyme mixture 2 added after the extrusion (ENZ2ex). ENZ1 and ENZ2 were used to evaluate the enzyme effect on extruder pre-conditioner (processing additive) and ENZ2ex to evaluate the effect of enzyme supplementation for the animal. Digestibility was measured through total collection of faeces and urine. The experiment followed a randomized block design with five treatments (diets) and six dogs per diet, totalling 30 dogs (7.0 ± 1.2 years old and 11.0 ± 2.2 kg of body weight). Data were submitted to analysis of variance and means compared by Tukey's test and orthogonal contrasts (p < 0.05). Reducing sugars showed an important reduction after extrusion, suggesting the formation of carbohydrate complexes. The apparent total tract digestibility (ATTD) of dry matter, organic matter, crude protein, acid-hydrolysed fat and energy was higher in NC than in diets with WB (p < 0.001), without effects of enzyme additions. WB diets resulted in higher faecal production and concentration of short-chain fatty acids (SCFA) and reduced pH and ammonia concentration (p < 0.01), with no effect of enzyme addition. The enzyme addition did not result in improved digestibility of a diet high in non-starch polysaccharides; however, only ATTD was measured and nutrient fermentation in the large intestine may have interfered with the results obtained. WB modified fermentation product formation in the colon of dogs. © 2013 Blackwell Verlag GmbH.

Mechanism and effect of esculetin in an experimental animal model of inflammatory bowel disease

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antimutagenic and anticarcinogenic effects of wheat bran in vivo

Previous studies in rodents treated with the pro-carcinogen 1,2-dimethylhydrazine suggested that the consumption of wheat bran protected against DNA damage in the colon and rectum. Based on this information, we evaluated wheat bran as a functional food in the prevention and treatment of colon cancer. We used the aberrant crypt focus assay to evaluate the anticarcinogenic potential of wheat bran (Triticum aestivum variety CD-104), the comet assay to evaluate its antigenotoxicity potential, and the micronucleus assay to evaluate its antimutagenic potential. The wheat bran gave good antimutagenic and anticarcinogenic responses; the DNA damage decreased from 90.30 to 26.37% and from 63.35 to 28.73%, respectively. However, the wheat bran did not significantly reduce genotoxicity. Further tests will be necessary, including tests in human beings, before this functional food can be recommended as an adjunct in the prevention and treatment of colon cancer. © FUNPEC-RP.

Infection patterns of Paradollfusnema amphisbaenia (Nematoda: Cosmocercidae) in a population of Amphisbaena wuchereri (Squamata: Amphisbaenidae) from Minas Gerais state, south-eastern Brazil, and its relations with host size, sex and fat body mass

Specimens (n= 41) of the amphisbaenid Amphisbaena wuchereri taken from a population in Minas Gerais state, south-eastern Brazil, were examined for gastrointestinal parasites. A single nematode species was found, Paradollfusnema amphisbaenia. This was a new host record for this nematode species. This parasite was encountered in the large intestine (prevalence of 100%), in the stomach (prevalence of 2%) and in the small intestine (prevalence of 7.3%). The intensity of infection ranged from 1 to 457 individual parasites per host and was positively correlated with body size of both male and female amphisbaenians. The discrepancy index (D) indicated that P. amphisbaenia tended to an even distribution in this host population. The nematode, which did not affect fat body mass, induced inflammatory infiltrations in the small intestine, indicating that the parasites might injure the host's organs. Copyright © Cambridge University Press 2012.

Efeitos da polpa do fruto de annona crassiflora mart., nos parâmetros bioquímicos e na carcinogênese de colon de ratos

A. crassiflora Mart. a Brazilian savannah fruit, is a source of phytochemical compounds that possess a wide array of biological activities, including free radical scavenging. This native fruit proved to potentialize the mutagenic process in previous in vivo investigations. The aim of the present study was to investigate the effects of A. crassiflora Mart. pulp intake on colonic cell proliferation and on the development of Aberrant Crypt Foci (ACF) in male Wistar rats. The animals were fed with either a commercial diet or a diet supplemented with A. crassiflora Mart. pulp mixed in 1%, 10% or 20% (w/w) for 4 weeks or 20 weeks. The carcinogen 1,2-dimethylhydrazine dihydrochloride (4 doses, 40 mg kg-1 each) was used to induce colonic ACF. After euthanasia, the blood, liver and colon samples were collected for biochemical determinations, oxidative stress or ACF development analysis, respectively. Immunohistochemical analyses of the colonic mucosa were performed using antibodies against proliferating cell nuclear antigen (PCNA) in normal-appearing colonic crypt and β-catenin in ACF. There was no ACF development in the colon from groups treated with A. crassiflora Mart. pulp. Also, the biochemical and oxidative stress analysis, PCNA labeling and ACF development (number, multiplicity or cellular localization of β-catenin) were unchanged as a result of marolo pulp intake. Thus, the present results suggest that A. crassiflora Mart. pulp intake did not exert any protective effect in the colon carcinogenesis induced by DMH in rats.

Evaluation of the antimutagenic and anticarcinogenic effects of inulin in vivo

The incidence of colorectal cancer is growing worldwide. The characterization of compounds present in the human diet that can prevent the occurrence of colorectal tumors is vital. The oligosaccharide inulin is such a compound. The aim of this study was to evaluate the antigenotoxic, antimutagenic and anticarcinogenic effects of inulin in vivo. Our study is based on 3 assays that are widely used to evaluate chemoprevention (comet assay, micronucleus assay, and aberrant crypt focus assay) and tests 4 protocols of treatment with inulin (pre-treatment, simultaneous, post-treatment, and pre + continuous). Experiments were carried out in Swiss male mice of reproductive age. In order to induce DNA damage, we used the pro-carcinogenic agent 1,2-dimethylhydrazine. Inulin was administered orally at a concentration of 50 mg/kg body weight following the protocols mentioned above. Inulin was not administered to the control groups. Our data from the micronucleus assay reveal antimutagenic effects of inulin in all protocols. The percentage of inulin-induced damage reduction ranged from 47.25 to 141.75% across protocols. These data suggest that inulin could act through desmutagenic and bio-antimutagenic mechanisms. The anticarcinogenic activity (aberrant crypt focus assay) of inulin was observed in all protocols and the percentages of damage reduction ranged from 55.78 to 87.56% across protocols. Further tests, including human trials, will be necessary before this functional food can be proven to be effective in the prevention and treatment of colon cancer. © FUNPEC-RP.

Mannanoligosaccharide (mos) and β-glucan (β-glu) in dietary supplementation for Nile tilapia juveniles dept in cages

This experiment was conducted at an aquicolous enterprise with the objective of evaluating the use of MOS and β-GLU as dietary supplements in an experimental lot in order to follow the zootechnical performance, establishing a relationship with the hematological parameters, the morphological alterations of the intestine, and the enzymatic activity (protease, lipase and amylase), and the water quality of 3,000 tilapia juveniles kept in cages (Wt = 24 ± 0.26g). Nine cages (6.0 m3) were used, with three treatments and three replications. 1: commercial feed without supplementation (control); 2: 0.1% per ton of MOS; 3: 0.03% per ton of purified β-GLU. The feed contained 36% of crude protein (CP) incorporated into the premix MOS and purified β-GLU (BIORIGIN®). The tilapia that had received the diet supplemented with β-GLU in a period of 90 days showed a favorable condition of the immune system, increase in the absorption surface of the front part of the intestine and consequently, growth in the activity of the digestive enzymes, denoting higher efficiency in the use of the nutrients in juveniles, providing satisfactory zootechnical performance in comparison with the other diets. This product may be used as a dietary supplement for this species when kept in cages.

Lipid metabolism of commercial layers fed diets containing aflatoxin, fumonisin, and a binder

Aflatoxins (AF) and fumonisins (FU) are a major problem faced by poultry farmers, leading to huge economic losses. This experiment was conducted to determine the effects of AF (1 mg/kg of feed) and FU (25 mg/kg of feed), singly or in combination, on the lipid metabolism in commercial layers and investigate the efficacy of a commercial binder (2 kg/t of feed) on reducing the toxic effects of these mycotoxins. A total of 168 Hisex Brown layer hens, 37 wk of age, were randomized into a 3 × 2 + 1 factorial arrangement (3 diets with no binder containing AF, FU, and AF+FU; 3 diets with binder containing AF, FU, and AF+FU; and a control diet with no mycotoxins and binders), totaling 7 treatments. The hens contaminated with AF showed the characteristic effects of aflatoxicosis, such as a yellow liver, resulting from the accumulation of liver fat, lower values of plasma very low-density lipoprotein and triglycerides, and higher relative weight of the kidneys and liver. Hepatotoxic and nephrotoxic effects of FU were not observed in this study. On the other hand, the FU caused a reduction in small intestine length and an increase in abdominal fat deposition. The glucan-based binder prevented some of the deleterious effects of these mycotoxins, particularly the effects of AF on hepatic lipid metabolism, kidney relative weight, and FU in the small intestine. © 2013 Poultry Science Association Inc.

Visceral colouration of Eupemphix nattereri (Anura: Leiuperidae): effects of NDP-α-melanocyte stimulating hormone

Amphibians have melanin-containing cells in visceral organs that are similar to pigmentary cells from the epidermis. Both of them are derived from the ectodermal neural crest. Epidermal cells respond to α-melanocyte stimulating hormone (α-MSH), which is associated to the dispersion of melanin granules within melanocytes. Therefore, our aim was to test whether a non-degradable analogue of the α-MSH changes the superficial colouration of organs of Eupemphix nattereri. The hormone rapidly increases (within 12 hours) the colouration on the surface of the pericardium, heart, testes, nerves of the lumbar plexus, and lumbosacral parietal peritoneum. Colouration increased late (after 24 hours) in the kidneys and mesentery following hormone administration. However, this hormone did not change colouration of intestine, rectum and lungs. Our findings could be explained by the similarities between epidermal and visceral melanocytes, since both cells have a common embryonic origin. Furthermore, the increase in visceral colouration may be related to the dispersion of melanosomes within melanocytes, which causes the darkening of organs. Our results demonstrate for the first time that the visceral colouration is responsive, thereby altering the internal pattern of organs' colouration in anurans. © 2013 Copyright 2013 Unione Zoologica Italiana.

Organically produced coffee exerts protective effects against the micronuclei induction by mutagens in mouse gut and bone marrow

While researchers have extensively evaluated the beneficial effects of coffee consumption in reducing the frequency of certain diseases, studies examining the differences between organic and conventional coffee intake are still needed. Therefore, this paper aims to investigate the functional effects of organic and conventional coffee by examining both its chemical composition and its mutagenic/antimutagenic properties. Infusions of 10% or 20% (w/v) of organic and conventional coffee were administered by gavage (10 mL/kg b.w., once or twice a day) to male Swiss mice against doxorubicin (DXR) and 1,2-dimethylhydrazine dihydrochloride (DMH)-induced mutagenicity. The levels of chlorogenic acids, caffeine and trigonelline from the coffee infusions and oxidative stress analysis from the liver were measured by HPLC. Gut and bone marrow micronucleus assays were used as mutagenic/antimutagenic endpoints, as well as the crypt measurements and gut apoptosis index. The in vivo tests revealed that only organic coffee exerted protective effects, despite oxidative stress analysis and crypt measurements not showing differences among treatments. Intriguingly, the low dose (10% w/v mL/kg) displayed a robust protective effect that showed a significant reduction in bone marrow micronuclei (26.8%), gut micronuclei (11.5%) and apoptosis (27.8%), whereas the higher coffee dose (2 × 20% w/v) only showed a protective effect against bone marrow micronucleus (43.7%). These results highlight that organic coffee could be considered to have beneficial functional effects, although it is still a challenge to define conclusions from analytical data and all the possible interactions from this complex food matrix. © 2013 Elsevier Ltd. All rights reserved.